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NISTR 7568

Programs, Activities, and Accomplishments

March 2009

NISTIR 7568

ELECTRONICS AND ELECTRICAL LABORATORY

U.S. Department of Commerce Gary Locke, Secretary

National Institute of Standards and March 2009 Patrick D. Gallagher, Deputy Director

INDEX

Electronics and Laboratory at a Glance ...... 6 Director’s Message ...... 7 EEEL Strategic Technical Area: ...... 8 EEEL Strategic Technical Area: Bioelectronics ...... 9 EEEL Strategic Technical Area: ...... 10 EEEL Strategic Technical Area: ...... 11 EEEL Strategic Technical Area: Homeland ...... 12 of Law Enforcement Standards ...... 14 Office of Programs ...... 16 Electronics Division ...... 19 Device and Thermal Metrology ...... 20 Micro-Nano-Technology (MNT) ...... 22 ...... 24 CMOS Device and Reliability ...... 26 Macro Electronics ...... 28 Nanoelectronic Device Metrology...... 30 for Integrated Electronics and ...... 32 Knowledge Facilitation ...... 34 Division...... 37 Display Metrology ...... 38 Radiometry...... 40 High-Speed ...... 42 Fiber Sources and Applications ...... 44 Quantum and Terahertz Technology ...... 46 Nanostructure Fabrication and Metrology ...... 48 Semiconductor Growth and Devices...... 50 Metrology ...... 52 Quantum Electrical Metrology Division ...... 55 Quantum Development and Dissemination ...... 56 Metrology of the ...... 58 Quantum Conductance/Graphene-Based Quantum Metrology ...... 60 AC-DC Difference ...... 62 and Impedance Metrology ...... 64 Electronic Kilogram ...... 66 Metrology and the ...... 68 Quantum ...... 70 Quantum Information and Measurements ...... 72 Quantum Magnetic Sensors and Materials...... 74 Electromagnetics Division...... 77 This document describes Advanced High Frequency Devices ...... 78 the technical programs of the Advanced Materials Metrology...... 80 Fundamental Guided- Metrology ...... 82 laboratory. Antenna Metrology...... 84 Field Parameter Metrology ...... 86 Contact NIST/EEEL, ...... 88 100 Bureau Drive, MS 8100, Nanomagnetics ...... 90 Gaithersburg, MD 20899-8100, Biomagnetics ...... 92 : (301) 975-2220, Superconductivity ...... 94 On the Web: www.nist.gov/eeel/

Electronics and Electrical Engineering Laboratory 5 ELECTRONICS AND ELECTRICAL ENGINEERING LABORATORY AT A GLANCE

One of NIST's and Standards Laboratories, the Electronics and Electrical Engineering Laboratory (EEEL) conducts , provides measurement services, and helps set standards in support of: the fundamental and practical physical standards and measurement services for electrical quantities; the fundamental electronic of , magnetics, and superconductors; information and technologies, such as fiber , , , electronic displays, and electronics manufacturing supply chain collaboration; forensics and security measurement ; maintaining the and integrity of electrical power ; and the development of nanoscale and microelectromechanical devices. EEEL provides support to law enforcement, corrections, and criminal justice agencies, including homeland security.

Vision

To be the world's leading electromagnetic measurements and standards laboratory.

Mission

To promote U.S. and industrial competitiveness by advancing measurement , standards, and technology, primarily for the electronics and electrical industries, in ways that enhance economic security and promote our quality of life.

Values

Integrity ...within our and in our interactions with our stakeholders

Impact ...through leadership in measurements and standards for our customers and the nation

Excellence ...in all of our undertakings

EEEL consists of four programmatic divisions and two -managed : Office of Law Enforcement Standards Office of Microelectronics Programs Semiconductor Electronics Division Optoelectronics Division Quantum Electrical Metrology Division Electromagnetics Division

6 Electronics and Electrical Engineering Laboratory DIRECTOR’S MESSAGE

The Electronics and Electrical Engineering Laboratory supports U.S. by developing measurement science and providing measurement services over the electromagnetic spectrum from DC to light . We provide measurements for DC and low-frequency voltage and current, through and terahertz quantities, from infrared to ultraviolet laser power and energy. Our world-class measurement services are supported by research efforts that develop the foundations for tomorrow’s measurement , and our talented and dedicated staff members strive to ensure that we are positioned to meet the nation’s most important measurement needs.

In this report, you will find that EEEL researchers are developing the world’s most advanced sensors, providing advanced gamma-ray imagers for astronomical researchers and single-photon detectors that test the limits of quantum information. Our and are leading the world in a new definition of the kilogram based on electrical units and developing and measurements to support a new generation of electronic devices. We are creating novel measurements of electrical and optical waveforms that provide frequency, phase, and temporal response at unprecedented accuracy and ever increasing bandwidths and data rates. Our research in bioelectronics is yielding new methods for analyzing DNA, and our efforts in bioimaging will improve the accuracy of magnetic resonance (MRI), thus improving diagnostic capability.

Our in and smart grid standards and measurements will improve electrical and address the nation’s energy concerns. Our job is to support U.S. innovation by addressing the most pressing electronic and electrical Kent Rochford, Acting Director measurement needs, and our staff members take this challenge seriously.

To learn more, please visit our , www.nist.gov/eeel/. We invite your and interest in our measurement offerings, measurement science developments, and opportunities for collaboration.

James Othoff, Deputy Director

Electronics and Electrical Engineering Laboratory 7 EEEL STRATEGIC TECHNICAL AREA: ENERGY

One of the most important issues facing the nation is the need to improve our energy infrastructure to be more flexible, efficient, and reliable while reducing negative environmental impacts. EEEL is on existing research programs in all of its divisions to better meet this need now and in the future. Our unifying vision is to improve the electric to become a new “Smart Grid,” providing a two-way flow of and information. By incorporating distributed , communications, and sensors into the power grid to improve its ability to respond to changes, the Smart Grid will become a more robust and innovative energy delivery platform capable of supporting distributed and renewable sources of energy (such as wind, solar, and geothermal) and new products such as plug-in electric and able to modify energy use in response to external conditions. Under the Energy Independence and Security Act of December 2007, NIST is given a new responsibility to “coordinate the development of a framework ... to achieve interoperability of Smart Grid devices and systems.” EEEL is currently leading NIST’s efforts to respond to this important and challenging mandate by boldly leading and orchestrating the efforts to develop the comprehensive standards structure necessary for the effective and rapid of Smart Grid technologies. These efforts include engaging a broad range of stakeholders through working groups and workshops, developing a shared vision of interoperability, fully assessing the current standards landscape, accelerating standards development by relevant standards , and recommending standards, policies, or practices to the Federal Energy Regulatory Commission (FERC) once stakeholder consensus is reached.

Metrology development and research in EEEL addresses all facets of our energy vision, including Smart Grid. Our electric power and energy calibrations help to ensure that electric power metering is accurate. Our measurements of power monitoring devices support the ability to monitor the operational state of the power grid in real time to minimize disruptions and outages. To support the Department of Energy (DOE), we have performed electrical efficiency testing for electrical equipment such as power and electric motors. We characterize new electronic materials such as carbide to support their use in advanced high-speed power electronics. Our measurements of superconductors support their use for energy applications such as for higher-capacity power transmission lines. Additionally, our measurements of advanced optoelectronic materials and organic semiconductors and devices support improved-efficiency solid-state and organic . Future work is also envisioned to improve energy generation and storage applications.

8 Electronics and Electrical Engineering Laboratory EEEL STRATEGIC TECHNICAL AREA:

BIOELECTRONICS “Bringing the Benefits of Moore’s Law to ”

Bioelectronics is a field of research that applies the recent advances in electronics to create medical equipment that will lower the cost of healthcare and improve the way in which doctors diagnosis and treat illness, cancer, and disease. It will provide tools for researchers that will help them to better understand how our bodies work. That knowledge will enable doctors to diagnose medical problems much earlier than they can now, so that treatments can be more effective and less invasive and costly. Electronic technologies have already revolutionized medicine with X-ray and MRI imaging technologies and a long list of other kinds of medical applications including blood measurements, electrocardiograms, and brain activity monitoring. In , electronics has become so reliable and ubiquitous in medicine that we don’t usually think about how important it has become in the plethora of applications that save lives every day. Bioelectronics will enable new advances in medicine by using the -chip technologies that have made processors smaller, faster, and cheaper, and NIST will help make them as commonplace and reliable as going to the 's office to take your blood pressure. Figure 1. Single-molecule mass spectrometry Bioelectronics encompasses a range of topics at the interface of and using electronic nanopore measurements electronics, including elements from electronics, , , (Robertson et al., PNAS 2008; 104:8207-8211). biomaterials, and bioengineering. One aspect of bioelectronics is the application The entry of individual poly(ethylene glycol) of electronics to problems in biology and medicine. This includes electronics for molecules into a single pore (top) causes transient detection, characterization, and measurement of biological materials, especially reductions in the ionic current. Larger polymers on the molecular, sub-cellular, and cellular . Another aspect is the block the pore conductance more than do smaller application of biological systems and/or processes to create novel electronic ones. Each peak in a histogram of molecule- components. A third aspect of bioelectronics is based on the interfacing of induced current blockade (bottom) electronics with biological systems—for example, brain- interfacing. corresponds to a particular size molecule in a Applications in this area include assistive technologies for individuals with brain- polydisperse sample. The difference in the length related disease or injury, such as paralysis, and artificial retinas. of the molecules that cause successive peaks is 3 Angstroms (red data). The blue trace corresponds EEEL has identified and is working on opportunities to develop new molecular to current blockades caused by a monodisperse and cellular instrumentation tools for (e.g., metrology for PEG sample with 29 ethylene glycol repeat units. biomolecule detection, identification, and quantification) and new methods to improve the bioelectronic interface (in-vivo electronic/biointerface chips). These include the use of protein nanopores for the detection and quantification of ions, RNA and DNA, proteins, and toxins; the use of single-protein nanopores for aqueous-based mass spectrometry (fig. 1); the use of solid-state nanopores and nanowires for biomarker detection; the ability to manipulate single particles with magnetic traps; the integration of microelectrodes to position cells and to observe growth and toxin response of cell ; the integration of microwave heating elements in microfluidic structures to control Figure 2. Integration of microwave elements and cycle (fig. 2); the use of microwave techniques to measure with microfluidic systems for pinpoint single cell ion channel events with 10 MHz ; the adaptation of micro- temperature control and cycling (Shah et al., mechanical beams to DNA characterization; and the ability to form disposable J. Micromech. Microeng. 2008; 17: 2224-2230). chips with integrated electrodes.

Electronics and Electrical Engineering Laboratory 9 EEEL STRATEGIC TECHNICAL AREA: NANOTECHNOLOGY

Nanotechnology opens new doors to tremendous innovation because material and device behavior is radically different at the nanoscale, allowing new properties and functionalities to emerge, but also creating significant new measurement challenges. Those who can this new functionality into new products and tools will tremendous competitive advantage and huge economic and technical rewards. EEEL is developing the measurement infrastructure that is necessary to facilitate the transition of nanotechnology from the lab to the commercial market. EEEL is also harnessing advances in nanotechnology to improve our quantum electrical standards to better tie the U.S. legal electrical standards to the international system of units and to ensure reproducible standard electrical measurements.

Nanotechnology is poised to make a huge difference in the $250 billion . EEEL is developing metrology that will help enable new nanoelectronic information processing technologies to supplement and/or supplant conventional complementary metal oxide semiconductor (CMOS) devices that are the of today’s integrated circuits. EEEL has made recent advances in creating test structures and associated test methods for determining the fundamental electrical properties of nanoelectronic components such as Si and GaN nanowire test structures and hybrid molecular/Si test structures. EEEL is developing the tools needed by scientists and engineers to quantify, design, simulate, and manufacture reliability into nanoscale devices. Novel defect characterization techniques have been developed and used to begin to determine the fundamental relationship between materials’ properties and nanoelectronic device reliability. New computational state variables other than electronic charge are highly desired in order for future, high- information processing devices to reduce the amount of energy per unit area that is necessary for operation. EEEL is making strong efforts to develop the metrology in areas such as spintronics and . EEEL is also making advances in magnetics and optical applications. For example, EEEL has demonstrated single-photon sources and detectors for applications such as novel quantum-based systems, quantum computing, and new quantum-based radiometry standards.

Before nanoscale components can fulfill their scientific, technical, and commercial promise, better methods are needed to control their growth, purification, and identification. EEEL has advanced the controlled growth of compound semiconductor quantum dots (InGaAs) and nanowires (GaN) for optoelectronic applications. By utilizing microfluidic methods, EEEL has demonstrated well-controlled nanoparticle formation. Laser-based methods have been utilized for the purification and inexpensive identification of nanotubes. High- performance have been fabricated by the directed assembly of Si nanowires.

Additionally, EEEL is exploiting novel properties in nanotechnological devices to improve our quantum electrical standards. Recent advances have been made in applying Josephson junction technology to improve the capabilities and dissemination of AC and DC voltage standards as well as quantum-based power generation standards. EEEL also is investigating whether the unique properties of graphene – a single layer of carbon atoms – can be harnessed to create better quantum resistance standards and improve the dissemination of the Ohm.

10 Electronics and Electrical Engineering Laboratory EEEL STRATEGIC TECHNICAL AREA: SPINTRONICS

Spintronics, which exploits the magnetic spin of the instead of its charge, has the potential to revolutionize the microelectronics industry, just as microelectronics revolu - tionized -based electronics and just as transistors revolutionized -tube electronics. Future spintronic devices will be 10 times faster, 15 percent the size, and use only about 1 percent of the energy of today’s conventional electronics. The goal of the EEEL Spintronics is to develop new tools and measurements that bring high-frequency metrology to the nanoscale in order to create “beyond-CMOS” spintronic devices and archi - tectures. The program has three thrusts: metallic spintronics (ferromagnet-based microwave spin-transfer nano-oscillators, spin-transfer magnetic random-access memory (MRAM), spin-wave interconnects, and spin analogs of electronic devices), molecular spin- tronics (molecular spin-resonance , single-molecule/nano-particle spin devices), and the development of a nanoscale workbench (to perform spatially resolved, high-frequency, broadband measurements of active nano-devices).

The growth in computing power is a consequence of smaller electronic devices working at higher frequencies. In charge-based devices, this to a significant increase in energy dissipation, which causes chips to get hot. This represents a significant design and performance challenge today, but by 2019 it is expected to halt the dimensional scaling of devices that are based on complementary metal-oxide semi conductors (CMOS). Spintronics could not only solve the heating problem but could combine computer logic with nonvolatile spin-MRAM.

Future applications of this technology include reference oscillators and directional microwave and receivers in devices such as cell phones and systems, Figure 1: Cross-sectional sketch of a spin- wireless chip-to-chip communications, nanoscale clocks, spectrum analyzers, and torque nano-oscillator. The two magnetic layers high-frequency processors. Other spintronic devices could be spin batteries, spin are “active” or “fixed” because of their different and transistors, spin signal mixers, and spin-wave interconnects. thickness and magnetization. A H is usually applied at some angle when studying A variety of organic materials have promising spin properties, and molecules can be gigahertz excitations in such devices. synthetically tuned at the atomic scale; thus, molecular electronic devices with spin- dependent tunneling offer an innovative approach in spintronics. EEEL is develo- ping test structures and methods to determine the fundamental spin-properties of organic materials and assess their use in spintronic devices. Tunneling in a monolayer array of 10,000 molecules between cobalt and electrodes has recently been demonstrated.

The nanoscale workbench will be an advanced metrology tool to measure the high- frequency response of active, nanoscale, spin, and molecular devices. The workbench will combine high spatial resolution with -frequency measurements to probe the Figure 2: of a nanopore frequency dependence of defects, the effects of hybridization of atomic energy device with a monolayer of self- bands, and environmental factors that can affect device performance. With this tool assembled molecules and the chemical EEEL will be able to measure spin decay lengths and decoherence times associated with structure of the octanethiol molecule. The spin currents in real devices and understand the roles of interfaces and structure. The arrow shows the direction of an applied workbench will operate over a broad range of device using an ultra-high magnetic field. vacuum chamber and four, broadband, scanning probes with tunneling .

Electronics and Electrical Engineering Laboratory 11 EEEL STRATEGIC TECHNICAL AREA: HOMELAND SECURITY

EEEL's role in homeland security began in 1999, when the laboratory's Office of Law Enforcement Standards (OLES) joined the nation's first concerted effort to develop standards for equipment to protect first responders against chemical, biological, radiological, nuclear, and (CBRNE) agents. This experience proved invaluable, and soon after September 11, 2001, OLES was awarded technical leadership of a broad range of programs focused on CBRNE countermeasures.

Today, OLES oversees scores of programs funded by the Department of Homeland Security (DHS). Many of these programs utilize technical resources and expertise within EEEL and elsewhere in NIST. In FY 2008 OLES's homeland security activities brought $25M into NIST, making OLES the recipient of the greatest amount of other agency funding at NIST. In addition, EEEL and OLES partner with DHS and other organizations to identify and address critical homeland security needs, and their personnel serve as key with DHS and chair/serve on dozens of technical committees and working groups.

Recent Accomplishments

• Conducted functional tests of radio-frequency identification (RFID) tags in realistic first responder environments • Developed and demonstrated that emergency response organizations can use to verify that their conform with the P25 Inter-RF Subsystem Interface (ISSI) • Developed a detection model that uses spectra to discriminate between hazardous (acetone, motor oil, bleach) and non-hazardous (apple juice, baby formula, shampoo) liquids

Project Descriptions

The following are a few examples of the exciting homeland security work being done at EEEL:

Performance Metrics and Transmission Standards for RF-Based Emergency Equipment • Determining how environmental conditions affect the performance of radio frequency-based personal safety systems. Land Mobile Radio (LMR) Standards and Technologies • Facilitating development of the suite of standards known as 25, which ensures the interoperability of first responder radios made by different manufacturers Liquid Detection Standards • Determining the feasibility of using microwaves to identify explosive liquids in nonmetal containers Standards for Near Infrared to Radar Frequency Detection of Explosive Devices • Improving the understanding of explosive devices and their electromagnetic properties

12 Electronics and Electrical Engineering Laboratory Electronics and Electrical Engineering Laboratory 13 OFFICE OF LAW ENFORCEMENT STANDARDS

When Congress created NIST’s Office of Law Enforcement (OLES) in 1971, no one imagined what it would achieve. A 1960s Presidential Commission had cited “lack of reliable technologies” as a major weakness in the criminal justice and public safety , and OLES was chartered to bring NIST’s world-class metrology and standards development talents to bear on the crisis. OLES is a program- organization within EEEL. The office and manages standards-development and research on behalf of agencies such as the Department of Homeland Security (DHS), the Department of Justice (DOJ), and others. OLES also maintains metrology activities and laboratories for equipment unique to law enforcement, criminal justice agents, and emergency responders.

In FY 2008 the office received approximately $55M from with the DOJ National Institute of Justice (NIJ) and Oriented Policing Services (COPS), and the DHS Science and Technology Directorate and its SAFECOM program. This funding makes OLES NIST's largest source of outside agency (OA) funding. These federal partnerships enable OLES to achieve its mission to develop metrology, standards, and test methods for and support of technologies essential to law enforcement and public safety agencies. Over the years, as the definition of public safety has expanded, so has the Office’s expertise.

Major Achievements

OLES began by developing in 1972 the first performance standard and testing program for ballistic body armor – bullet-resistant vests. That effort, which continues today, is credited with saving the lives of more than 3,100 law enforcement officers in the U.S. and countless thousands of law enforcement, corrections, and security personnel worldwide. Yet it was just the beginning.

Over the decades, OLES has: • developed 300+ standards, equipment guides, and technical reports on technologies ranging from metal detectors and mobile radios to protective gloves and pepper spray; • developed, beginning two years before September 11, 2001, standards for personal protective equipment for chemical, biological, radiological, nuclear, and explosive (CBRNE) threats – an effort that earned OLES its current position managing the development of performance standards for DHS; • conducted groundbreaking work in forensic science that has pioneered advances in arson, ballistics, , and DNA analyses; and • expanded its early work on radio technologies into a central role in developing nationwide interoperable communications for emergency responders.

Professionalism and Partnerships

OLES’s strengths are its exceptional staff and its partnerships. OLES staff members are recognized experts in a wide range of disciplines. They hold memberships in

14 Electronics and Electrical Engineering Laboratory scores of technical and scientific organizations, chair technical reference data sets and field investigation guides • computer and policy-making committees in those organizations, and forensic tool testing • fire investigation tools for scenes, work closely with the public and private sectors. OLES’s fire modeling, and burn pattern recognition • Standard partnerships are many – federal agencies, practitioners, Reference Materials (SRMs) for bullets and standards for bullet academia, industry, non-government standards bodies, and casings • SRMs for DNA analyses • DNA assays and scientific and technical organizations. software • equipment and software validation • and forensic training. The program has also updated essential SRMs for glass Program Descriptions refractive index and glass density (needed to calibrate instruments used to analyze glass evidence) and developed a Below are brief descriptions of some activities underway in the method for enhancing unerased audio on magnetic tape – a Office’s six Program Areas. significant development in audio forensics.

Critical Incident Technologies (CIT) deals with technologies Public Safety and Security Technologies (PSST) studies essential for rapid first response. Working with DHS, and other chemical-based less-than-lethal technologies, such as pepper federal partners, CIT develops performance standards, test spray, and technologies for detecting CB agents and explosives. protocols, reference materials and reference data, conformity The program focuses on: reference materials for testing assessment programs, and guides to help first responders select biothreat detection devices and instruments • ability of devices reliable equipment and services. CIT programs encompass: to detect chemical warfare agents and toxic industrial chemicals chemical detectors • and nuclear detectors • X-ray and • field-deployable standard explosive test materials • gamma-ray screening systems • chemical respirators and personal performance standards for chemical systems such pepper spray protective equipment (PPE) • chemical and biological (CB) suits and saliva specimens for drug testing • and law enforcement riot and ensembles • decontamination equipment • protective clothing gear designed for use in violent situations. PSST also develops and monitoring systems for firefighters • electronic devices for CB protection equipment guides with information for firefighting environments • urban search and rescue • evaluating and purchasing safe and reliable equipment. security sensors and networks • radio-frequency (RF)- based security and emergency response equipment • building Public Safety Communications Systems (PSCS) helps to blast and fire resistance • first responder credentials • latent implement a standard nationwide system that enables all law fingerprint evaluation • and biometric technologies. enforcement and public safety agencies to communicate and share data across jurisdictional and technological boundaries. PSCS Detection, Inspection, and Enforcement Technologies (DIET) works with DHS SAFECOM and DOJ COPs to leverage existing expands the use of the electromagnetic spectrum for detecting standards and requirements, advise IT and wireless standards concealed threats. DIET developed the first committees, and evaluate commercial devices that can provide performance standard in the 1970s and has advanced the interim interoperability. Through its oversight of the Public Safety technology ever since. Today the program explores other Communications Laboratory, PSCS advances interoperability segments of the spectrum – from microwave to ultraviolet – for related to: land mobile radios • Voice-over- Protocol • use in security and law enforcement. Current programs focus on Radio Over Wireless Broadband • interoperability devices • standoff detection and imaging of concealed objects • metrology emerging technologies such as SDR, cognitive radio, and MANET • for detection and tracking of individuals behind barriers • RF and data exchange. It also conducts studies in fundamental areas technologies to capture biometric information such as respiration, such as and audio quality and RF propagation. heart rate, body , and voice • checkpoint detection of metal objects • detectors of hazardous liquids • thermal imaging and Protective Systems (WPS) provides ongoing for firefighters • portable X-ray systems for bomb squads • and technical support and research for the NIJ standard for complex scene projectors. The program also characterizes ballistic-resistant body armor. Its evaluation of new materials performance and is developing a reliable method for testing and ballistic threats, along with its ongoing revisions of the electroshock weapons such as Tasers. current standard, help ensure continued effectiveness of this key technology. The program also develops and supports Forensic Sciences develops tools that enable responders and standards for other essential equipment, including: stab- investigators to gather, handle, and analyze evidence safely and resistant body armor • ballistic helmets • bulletproof glass • riot in ways that ensure its integrity in court. The program focuses helmets • ballistic shields and plates • armor • metallic on: the National Software Reference Library • electronic crime handcuffs • and firearms and holsters.

Electronics and Electrical Engineering Laboratory 15 OFFICE OF MICROELECTRONICS PROGRAMS

The , which contributed approximately $7T to the U.S. in 2007 and has enabled rapid productivity improvements across multiple sectors, relies on the microelectronics industry for vital components. The microelectronics industry, in turn, relies upon NIST for measurement science and technology to help them meet their own aggressive goals for growth. NIST works closely with industry to develop and apply enabling technology, measurements, and standards to both support today’s production and build capability for future technology generations.

Historical Perspective

NIST’s predecessor, the National Bureau of Standards (NBS), began work in the mid- to meet the measurement needs of the infant semiconductor industry. While this was initially focused on transistor applications in other government agencies, in the early 1960s the Bureau sought industry guidance from the American Society for Testing and Materials (ASTM) and the U.S. Electronic Industries Association (EIA). ASTM’s top priority was the accurate measurement of silicon resistivity. NBS scientists developed a practical nondestructive method 10 times more precise than previous destructive methods. The method is the basis for five industrial standards and for resistivity Standard Reference Materials widely used to calibrate the industry’s measurement instruments. The second project, recommended by a panel of EIA experts, addressed the “second breakdown” failure of transistors. The results of this project have been widely applied, including solving a problem in main control responsible for delaying the launch of a shuttle.

Industrial Metrology Needs

By the late 1980s, NBS (now NIST) recognized that the semiconductor industry was applying a much wider range of science and engineering technology than the existing NIST program was designed to cover. The necessary expertise existed at NIST, but in diverse parts of the organization. In 1991, NIST established the Office of Microelectronics Programs (OMP) to coordinate and fund metrological research and development across the agency and to provide the industry with easy single-point access to NIST’s widespread projects. Roadmaps developed by the U.S. Semiconductor Industry Association (SIA) have independently identified the broad technological coverage and growing industrial needs for NIST’s semiconductor metrology developments. As the available funding and the scope of the activities grew, the collective technical program became known as the National Semiconductor Metrology Program (NSMP), operated by the OMP.

16 Electronics and Electrical Engineering Laboratory The NSMP has stimulated a greater interest in semiconductor metrology, motivating most of NIST’s laboratories to launch additional projects of their own and to cost-share OMP-funded projects. Most but not all, of OMP’s projects are partially funded by the NSMP, which directed a $12 million budget in fiscal year 2008.

Fostering NIST’s Relationships with the Industry

NIST’s relationships with the SIA, SEMATECH, and its subsidiary, International SEMATECH Manufacturing Initiative (ISMI), and the Semiconductor Research Corporation (SRC) are also coordinated through the OMP. Staff members from OMP and NIST Laboratories represent NIST on the SIA committees that develop the International Technology Roadmap for Semiconductors (ITRS), as well as on numerous SRC Technical Advisory Boards. In 2007, NIST initiated a funding program for the Nanotechnology Research Initiative (NRI) providing $2.8M a year for five years. NRI is a subsidiary of the SRC. NIST staff members are also active in the International Electronics Manufacturers Initiative (iNEMI), the EIA, the International Organization for Standardization (ISO), and Semiconductor Equipment and Materials International (SEMI). NIST supports the U.S. National Committee Technical Advisory Group for the International Electrotechnical Commission Technical Committee TC113 on Nanotechnology Standardization for Electrical and Electronic Products and Systems (Technical Advisor, USNC TAG for IEC TC 113 on nanotechnology) by funding the Technical Advisor to that organization.

NIST supports, together with the SRC, a graduate student at one of the SRC . This year the recipient is from the of at Amherst. He is a student working with Prof. James Watkins at the National Science Foundation (NSF) Center for Hierarchical Manufacturing. The student has already accepted an appointment for the summer of 2009 to work at in Chandler, AZ.

Electronics and Electrical Engineering Laboratory 17 18 Electronics and Electrical Engineering Laboratory SEMICONDUCTOR ELECTRONICS DIVISION

The primary mission of the Semiconductor Electronics Division is to provide the "Bioelectronics is the discipline measurement and software infrastructure to U.S. industry for mainstream silicon resulting from the convergence of CMOS (complementary metal-oxide semiconductor) and beyond CMOS biology and electronics and it has the technologies, as well as other advanced semiconductor technology needs. The potential to significantly impact many division provides necessary measurements, physical standards, and supporting data areas important to the nation's and technology; associated generic technology; software for improving economy and well-being, including interoperability; and fundamental research results to industry, government, and healthcare and medicine, homeland academia. Its programs also respond to industry measurement needs related to security, forensics, and protecting the bioelectronics, microelectromechanical systems (MEMS), power electronics, environment and the food supply." organic/ electronics, and various sub-areas of nanotechnology including nanoelectronics, nanocharacterization, nanoreliability, nanobiotechnology, and - from A Framework for Bioelectronics: nano- and micro-. Discovery and Innovation, pg. 1 (Feb. 2009) The division has extensive interactions with individual companies, industry organizations, professional societies, and universities; these activities enable the development of a research agenda responsive to the needs of industry and the nation. Active participation in industry roadmapping, such as the Semiconductor Industry Association's International Technology Roadmap for Semiconductors (ITRS), and standards development activities for SEMI are practiced by the division to prioritize and establish programs with the highest potential impact. Division researchers work with SEMI on new standards to help guide the future path of the semiconductor electronics industry in areas such as MEMS, high-k , e- diagnostics, e-manufacturing, time , and traceability. The division helps shape the future direction of semiconductor technology by providing innovative metrology breakthroughs that will propel our industry forward. The division widely disseminates the results of its research, especially in the areas of methods and Standard Reference Materials (SRMs), through a variety of channels: publications, software, conferences and workshops, and participation in standards organizations and consortia.

The division, with a staff of about 80 including full-time and part-time employees as well as guest researchers, post-doctoral associates, contractors, and students, is based in Gaithersburg, Maryland, and is one of four divisions within the Electronics and Electrical Engineering Laboratory at NIST. The division's technical activities are organized into three groups: the Enabling Devices and ICs Group, the CMOS and Novel Devices Group, and the Electronic Information Group. The division assists industry by providing tools such as new or improved measurement methods, SRMs, test structures and chips, and software that support the needed measurement infrastructure. Division personnel visit industrial sites, host a variety of visitors, and make available tutorial material on an as-needed basis. We also are active in conference and workshop activities that directly benefit the industry.

Electronics and Electrical Engineering Laboratory 19 POWER DEVICE AND THERMAL METROLOGY

Summary Description

Power converters for , -mode power conversion, silicon carbide (SiC) that are plug-in electric/hybrid-electric using power semiconductor devices beginning to replace conventional vehicles, alternate/clean power and other passive power electronic devices made with silicon. Power generation, and the advanced components, provides the means to semiconductor devices made with power delivery grid rely on the convert power from one voltage to SiC enable operation at higher advancement of power another, to convert between direct , higher speeds, and higher semiconductor devices to succeed. current (DC) and temperatures. These new devices are Producers of power (AC) power, and to control motion necessary to meet the nation’s semiconductor devices want their by delivering electrical power to energy and defense priorities. products to handle higher motor windings or mechanical The project is addressing a wide voltages and temperatures and to . As power semiconductor range of key issues from methods to operate at higher frequencies, technology has evolved from slow, monitor material degradation in SiC thus enabling power converters low-voltage, low-power devices to power semiconductor devices to with higher efficiencies and lower today’s fast, high-voltage, high- methods to avoid development of costs. New semiconductor power devices, switch mode power hot spots in . The materials and devices to address conversion has become pervasive project has pioneered electrical and these needs are rapidly being and essential in all electrical and thermal measurement methods for developed, but with these new electronic equipment except for IGBTs, advanced SiC power devices, materials and devices come new in the most extreme conditions such and high-density integrated circuits requirements for characterizing as very high-voltage, high- and has transferred these their performance and reliability. temperature, and cost-sensitive measurement systems to industry. The Power Device and Thermal products. The project is also playing a central Metrology Project is developing NIST provided the theoretical role in initiating and leading federal the new electrical and thermal foundation, measurement methods, programs to develop advanced measurement methods and and equipment that led to the power semiconductor devices equipment necessary to development and rapid adoption of necessary to meet the nation’s characterize these devices. This the most widely used high-power power conversion needs for power project has played and will , the Insulated generation and delivery, advanced continue to play a major role in Gate Bipolar Transistor (IGBT). As naval ship power distribution the growth of the power the IGBT reached its fundamental systems, secure power grids for semiconductor, power electronics, limits, NIST work began to focus on army main and forward bases, and and energy systems industries. devices made with new wide-band- plug-in hybrid and electric gap semiconductor materials such as propulsion vehicles.

20 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Provided leadership, data, theoretical models, and analysis for the DARPA High Power Electronics program necessary to develop the first SiC power modules and solid state power substation. • Initiated and led DOE efforts on grid connection of alternate/clean energy sources and identified methods to substantially reduce cost and improve performance and efficiency. • Developed test structures and methods to determine spatial and temporal resolution of transient thermal and demonstrating that NIST- developed calibration method provides ten-fold improvement in transient temperature accuracy.

Selected Publications

• A. R. Hefner, "Performance Analysis of 10 kV, 100 A SiC Half- Power Modules," in Proceedings of the Government Microcircuit Applications and Critical Technology Conference (GOMACTech) 2008 (2008) • T. H. Duong, J. M. Ortiz-Rodriguez, R. N. Raju, A. R. Hefner, "-Thermal of a 100 A, 10 kV Half-Bridge SiC MOSFET/JBS Power Module," in Proceedings of the 2008 IEEE Power Electronics Specialists Conference (PESC) (2008) • A. R. Hefner, “Power Conditioning System Technologies for High- Megawatt Fuel Cell Plants,” in 2008 Office of Fossil Energy Fuel Cell Program Annual Report, www.netl.doe.gov/technologies/coalpower/fuelcells/seca/refshelf.html

Figure 1. Performing high-speed, high-voltage silicon carbide device characterization using NIST-developed, specialized equipment.

Image Copyright Robert Rathe

Contact

Allen Hefner

(301) 975-2071

[email protected]

Electronics and Electrical Engineering Laboratory 21 MICRO-NANO-TECHNOLOGY (MNT)

Summary Description

Imagine if your cell phone could The of the in to produce integrated circuits to include test your food for salmonella 1959 marked the beginning of the new functionality at the chip level, such as when an alert was issued by the microelectronics revolution. From that sensors and actuators. This Centers for Disease Control and date to the present, the primary goal of offers the possibility of creating systems Prevention (CDC) or take a drop the microelectronics industry has been to of unprecedented complexity and power, of your blood, analyze it, integrate ever-larger numbers of even but also introduces new challenges for and send the results to your smaller transistors to produce faster and metrology. Every new function beyond doctor when you were sick. more powerful integrated-circuit chips. the classical ones of amplification, Further imagine if it could The industry’s continued success in , , and filtering consult with your doctor about achieving this goal has been requires development of new on-chip the optimum treatment, immortalized in Moore’s Law, which measurement capability including manufacture the required drugs, requires roughly doubling the number of appropriate standards. and inject microrobots into your transistors on state-of-the art computer The activities of the project fall into three blood stream to deliver the memory and logic chips every eighteen major areas. The first area, which is called drugs to the organs where months. In fact, Moore’s Law, which has Standards for Micro Technologies, is they were needed. been incorporated in The International addressing the technology and metrology This is the promise of the Technology Roadmap for Semi- needed to support the integration of microelectronics revolution conductors (ITRS), is the foundation microcircuits, microfluidic devices, micro- as it progresses into the 21st upon which many new technologies sensors, and micro-actuators, including century – even smaller and even were built and many old technologies the emerging field of microrobotics, more powerful. The goal of this were dramatically improved. It is no which has the potential to revolutionize EEEL project is to provide the exaggeration to say that these nano-manufacturing technology and metrology required to support technologies have revolutionized the health care. The second major project the evolving micro- and nano- world in fundamental ways. area, Cellular Bioelectronics Metrology, is technologies that are the basis Now, a new paradigm, which is adding focused on the technology and metrology for the microelectronics completely new capabilities to integrated needed to enable a Smart Petri Dish, which industry’s relentless progress circuit chips, is a rapidly growing will provide highly integrated electronic as it shifts its emphasis from component of the microelectronics means to carry out conventional cell ever increasing computational industry’s roadmap. This component, growth and measurements. The power to a diverse set which is often referred to as “More than third major project area, Nano of sensor and Moore” to distinguish it from Moore’s Law Electromechanical Systems, is concerned applications. scaling, is based on applying, adapting, with developing and applying microfluidic and extending the same technology used and nanofluidic devices to the formation,

22 Electronics and Electrical Engineering Laboratory characterization, separation, and collaboration on the recent development measurement of nanoparticles, including of a nano-scale glass-blowing technology.

Major Accomplishments

• Developed and demonstrated a single-mask process for fabricating nanofluidic devices with complex out-of-plane topography that will provide improved performance in manipulating and characterizing nanoparticles. • Developed novel techniques for measuring microhotplate temperature in-situ and demonstrated the long-term repeatability of these techniques that makes them suitable to support Built-in Self-Test (BIST) in microhotplate-based gas sensors. • Developed and demonstrated liposome nanoparticle formation in microfluidic devices that provides unprecedented control of nanoscale-liposome size and size distribution for innovative drug delivery and nanoparticle environmental health and safety.

Selected Publications

• J. C. Marshall et al., “Young's Modulus Measurements in Standard IC CMOS Processes Using MEMS Test Structures,” IEEE Electron Device Letters, Vol. 28, No. 11, pp. 960-963 ( 2007) • A. Jahn et al., “Preparation of Nanoparticles by Continuous-Flow ,” Journal of Nanoparticle Research, Vol. 10, No. 6, pp. 925-934 (2008) • E. A. Strychalski et al., “Non-Planar Nanofluidic Devices for Single Molecule Analysis

Figure 1. High Resolution Transmission Electron (HRTEM) image of a portion of a linewidth test structure showing the atomic planes used to accurately determine the width of the structure. Figure 2. Figure 3. Layout for a MEMS test structure chip Photograph of the NIST micro , which is probably the world’s smallest. that has been fabricated with a standard CMOS IC process to serve as a reference material for a number of different physical properties important for MEMS devices.

Contact

Jon Geist

(301) 975-5484

[email protected]

Electronics and Electrical Engineering Laboratory 23 NANOBIOTECHNOLOGY

Summary Description

Each person, like his or her Over 60 years ago, the ability to make that the ability to simultaneously detect thumbprint, is unique. However, precise and quantitative electronic and quantify many biological molecules medicine for disease is distributed measurements in living cells made it (or biomarkers) is essential to understand to patients as if they are all the possible to understand the molecular basis human wellness and disease. That will same. In the future, in a manner of nerve activity and how single biological require a significant breakthrough in similar to a home blood glucose molecules work. One of the metrology because each human cell can test, a single drop of blood will Nanobiotechnology Project’s goals is to express over 30,000 different proteins allow doctors to accurately take this metrology paradigm to the next and many other types of biomarkers. In prescribe preventative treatment level: to combine electronic and optical addition, because cells and tissues are and/or medicine that is tailored measurements to address critical needs in time-dependent and complex, to that individual’s needs. health care and homeland security. The understanding how therapeutic agents This new era of personalized methods under development will provide a affect them is an open question. medicine will benefit patients better understanding of complex dynamic Conventional metrologies are not up to directly by correctly identifying processes in cells, organs, and tissues, by this task. Therefore, new systems that can and properly treating disease detecting, identifying, and quantifying determine the state of a particular patient, in its early stages. specific biological molecules, including and monitor the effect of therapies on his This advance in health care will RNA, DNA, proteins, and other or her health, are needed to achieve the have an enormous impact on the biomarkers. This research will to goal of personalized medicine. quality of life. Economic benefits integrated microfluidic and microelectronic Electronics has the potential to address will also be substantial because systems that will be much more powerful these challenging measurement issues better therapies will lead to than the current generation of blood because semiconductor devices can be longer and more productive lives glucose sensors that revolutionized point- miniaturized, are scaleable, make use of and lower health care costs. of-care diagnostics for diabetics. systems integration, and have the EEEL’s Nanobiotechnology Project The reductionist paradigm, which has appropriate dynamic and temporal is developing technologies that brought about spectacular gains in our characteristics. Techniques that hold will permit the accurate understanding of physical and chemical promise, and that are just emerging from and simultaneous measurement systems, has been applied to biology and the fields of bioelectronics and biophysics, of many tiny biological molecules culminated with the sequencing of the include nanotransducers (nanopores, that indicate how well our entire human genome. While powerful, nanowires), single-molecule optical organs and tissues are working this approach has not provided a complete characterization, and manipulation and and how they respond to understanding of how cells and organs isolation approaches (including treatments. work. The new Systems Biology dielectrophoresis, laser tweezers, and Personalized Medicine approach suggests microfluidics). These and related techniques

24 Electronics and Electrical Engineering Laboratory must be further advanced and validated, so distinguish between molecules that differ that measurements of complex molecular in length by only 0.3 nm. interactions with single molecule sensitivity In addition, with scientists in the NCNR, can be made available to researchers and CSTL, and elsewhere, Nanobiotechnology the healthcare community. Project staff members are developing Towards that goal, project staff members methods for determining the structure of are developing new nanoscopic tools for integral membrane proteins, which are the biomarker metrology. For example, principal targets of health-related researchers have shown that single therapeutic agents. By design, the nanopores can be used to identify and used in these studies contain membrane quantify ions, RNA, DNA, proteins, and mimics that will also serve as a platform for toxins. They have also demonstrated that the personalized medicine systems similar conductance-based methods can described above.

Major Accomplishments

• Developed a new method to determine the structure of membrane proteins, which will help pharmaceutical companies design better drugs for the health care industry. • Devised an electronic method to measure the interaction between anthrax toxins, which will aid in the development of therapeutics against this biowarfare agent. • Developed a method to extract single mitochondria from cells, a technique that could prove useful for identifying human remains that are damaged (e.g., in combat or terror attacks) and for determining the cause of certain diseases. • Invented a conductance-based method to determine the size (or mass) of individual single molecules in solution. This significant advance should enable the electronic detection of many different types of biomarkers simultaneously on a single chip.

Selected Publications

• J. J. Kasianowicz, J. W. F. Robertson, E. R. Chan, J. E. Reiner, V. M. Stanford, “Nanoscopic Porous Sensors,” Annual Reviews of Analytical 1, 737-766 (2008) • B. J. Nablo, K. M. Halverson, J. W. F. Robertson, T. L. Nguyen, S. Bavari, R. G. Panchal, R. Gussio, O. V. Krasilnikov, J. J. Kasianowicz, “Probing the Bacillus Anthracis PA63 Channel with Nonelectrolyte Polymers,” Biophys. J. 95, 1157-1164 (2008) • J. W .F. Robertson, C. G. Rodrigues, V. M. Stanford, K. Rubinson, O. V. Krasilnikov, J. J. Kasianowicz, “Single Molecule Mass Spectrometry in Solution Using Solitary Nanopores,” Proc. Natl. Acad. Sci (USA) 104, 8207-8222 (2007) Contact Figure 1. The binding of Edema Factor toxin (yellow) to a Protective Antigen nanopore (orange) is a John J. Kasianowicz critical step in anthrax-induced death and can be monitored electronically. Specifically, the presence of even a trace amount of Edema Factor (EF) can be readily detected because it (301) 975-5853 blocks the current through the pore for positive potentials. EEEL demonstrated that this electronic method could be used to rapidly screen for therapeutic agents to inhibit the [email protected] interaction of these two toxins. The cell membrane mimic (purple) is 4 nm thick.

Electronics and Electrical Engineering Laboratory 25 CMOS DEVICE AND RELIABILITY

Summary Description

Microelectronics play an Electronic devices and their reliability the of flicker and increasing role in many critical have long been important topics of random fluctuations in a device’s aspects of our daily lives, research at NIST. Over the years, NIST operational parameters. Such including use in airplanes, has played a central role in this phenomena can be potential show automobiles, and medical important field. Many of the commonly stoppers. The physical origin of applications. As a result, an used test structures and test these fluctuations could be the electronics failure is increasingly methodologies in the industry were first result of only one broken bond or more life-threatening, and developed at NIST. NIST also led many “trap” in the vicinity of the device’s reliability assurance is needed of the national and international channel region. Project now more than ever before. As standard setting efforts and helped are using advanced high-speed electronic devices are write the testing protocols. Now, capture techniques to monitor and miniaturized down to the nano industry cannot keep up with the analyze the noise and fluctuations scale, reliability assurance is increasing pace of introducing new over long periods of time. Such data becoming much more complex materials and new device structures into will provide insight into the location and challenging due to new advanced semiconductor technology. and physical origin of the defects degradation mechanisms that Project researchers are responding to responsible. come into play as structures get industry needs by investigating failure New material systems such as high- smaller and to the inherent modes and degradation phenomenon in permittivity gate dielectrics and III-V difficulties in measuring such nano scale CMOS (Complimentary semiconductors are being investigated effects in as-manufactured Metal Oxide Semiconductor) devices as possible replacements for silicon- structures. The goal of this project with as small as 45 nm and based CMOS technology. Other efforts is to develop new test methods, “wire” devices with much smaller in the project include characterizing characterization procedures, and dimensions. One particular degradation defects in hafnium oxide/ models to enable the process affects p-channel devices and is arsenide devices and semiconductor industry to extremely difficult to characterize, understanding their chemical . A continue to manufacture requiring novel high-speed techniques combination of electrical and optical integrated circuits for reliable to capture the full extent of the techniques is being used to determine electronics and to make the jump degradation. A suite of specialized the band structure and energy barriers into revolutionary new instrumentation is being developed to in such systems. There is also work in technologies that will present probe these effects at even higher determining the long-term reliability of even more severe cross-cutting speeds. devices fabricated using silicon carbide. reliability challenges. Another phenomenon of concern in Special high-temperature probe extremely small electronic devices is stations capable of heating samples to

26 Electronics and Electrical Engineering Laboratory 400°C were developed to perform the gate dielectric. These data are the time-dependent dielectric breakdown first of their kind and are being used to tests on the silicon oxide layer used as project the lifetime of the devices.

Major Accomplishments

• Developed the world’s fastest pulsed current-voltage sweep measurement, achieving a complete high-fidelity sweep of the transistor’s operational characteristics in 2 s. This allows -induced degradation to be fully measured before it relaxes. These data will help project the lifetime of devices under realistic operating conditions. • Developed a high-accuracy method for characterizing the bias-temperature- instability phenomenon in (metal-oxide semiconductor field-effect transistors). Such a method is important for industry to be able to obtain accurate parameters for reliability models. • Discovered a new electron trapping and detrapping mechanism in the negative-bias- temperature-instability of p-MOSFETs that was not comprehended in previous studies. The mechanism helps explain degradation data published in earlier studies. • Developed a high-speed capture method to obtain and analyze random telegraph signal (RTS) fluctuations in nano-scale CMOS devices. These data suggest that the assumed over the last several decades to explain the origin of the noise is not correct. A new model is being formulated.

Selected Publications

• L. Yu, K. P. Cheung, J. S. Suehle, J. P. Campbell, K. Sheng, A. J. Lelis, S.-H. Ryu, “Channel Hot-Carrier Effect of 4H-SiC MOSFET,” European Conference on Silicon Carbide and Related Materials, Barcelona, Spain (2008) • J. P. Campbell, K. P. Cheung, J. S. Suehle, A. Oates, “Electron Trapping: An Unexpected Mechanism of NBTI and Its Implications,” 2008 VLSI Technology Symp., Hawaii, USA, pp. 76-77 (2008) • J. P. Campbell, K. P. Cheung, J. S. Suehle, A. Oates, "Negative-Bias Temperature Instability Induced Electron Trapping," Appl. Phys. Lett. vol. 93, no. 3, p. 033512 (2008).

Figure 1. Loading 12” containing state-of-the-art CMOS devices into a probe station in preparation of making high-speed measurements of transient changes in device characteristics due to temperature-bias stress.

Figure 2. Panel discussion during the recent Reliability Forum held at NIST. The Forum was Contact jointly sponsored by SRC, NIST, and ISMI. Experts from 32 organizations around the Kin P. Cheung world representing industry, academia, and government participated. The looming crisis in (301) 975-3093 reliability assurance of advanced microelectronics was addressed with a vision [email protected] for setting future reliability research directions.

Electronics and Electrical Engineering Laboratory 27 MACRO ELECTRONICS

Summary Description

The concept of electronic paper and The Macro Electronics Project was printable technology for flexible wearable electronics used to be a established in 2005 to address electronics. Extensive studies of product of . metrology gaps that limit or prevent the fundamental charge transport in these This futuristic concept for new commercialization of electronics novel materials systems allowed the electronics is closer to reality than incorporating thin-film active electronic development of -based device most people know and represents a materials and devices. Like silicon in its models that accurately describe the fundamental change in the infancy as a technology, there is much electrical characteristics of transistors. industry. This is that remains unknown about the Understanding of macroscale device macro electronics – thin, flexible, electronic, structural, and chemical operation was greatly enhanced by the portable, and cheap – and it properties of new materials expected development of -voltage promises to revolutionize how to find use in macro electronic measurements and analysis methods as people interact with electronics and applications. Additionally, there exists a a means to characterizing the electronic impact the quality of life. Imagine limited understanding of what properties of the channel region and electronics so cheap that they can be deleterious extrinsic effects may be parasitic contact effects for organic printed directly onto food packaging introduced during material processing, TFTs. Researchers have also to give real-time freshness status, or how to optimize device to demonstrated correlations between unrolling solar cell arrays to minimize parasitic effects that limit the molecular design, microstructure, and power up temporary shelters. extrinsic electrical performance, and electronic properties for organic thin Researchers at EEEL are developing the physical mechanisms responsible film and single crystal field-effect high-impact measurements that for electrical drift phenomena and transistors. investigate the most promising device failure. Metrology that provides Researchers are also developing means to enable commercialization insight to the above allows the rational metrology to enable organic-based of new and diverse macro electronic design of new materials and photovoltaic devices as a commercially technologies for a growing list of accelerates the development of viable technology for providing low- large-area consumer electronic computer-aided physics-based tools cost . Initial emphasis applications. There is a tremendous for macro electronic device design and has been placed on developing commercial market potential for circuit simulation. metrology that will increase the these electronics: printed and Project researchers initially focused on fundamental understanding of is a $400M-per- developing metrology and measurement photophysical and electronic processes year industry as of 2008, and it is methodology for thin-film transistors in photovoltaic devices to allow rapid expected to reach $15B (TFTs) based on solution-processed and significant improvements in per year by 2015. organic semiconductors (polymeric and materials synthesis and device small-molecule); a potentially cheap engineering and processing.

28 Electronics and Electrical Engineering Laboratory Most recently, project researchers in than organic-based devices given collaboration with Penn State their compatibility with existing University began addressing semiconductor processing methods, metrology gaps that may limit the and they may provide significant commercialization of zinc oxide TFTs improvements in electronic as a high-performance alternative to performance. Preliminary studies hydrogenated amorphous silicon have focused on understanding technology (second in economic device reliability and stability, as well importance only to single crystal as fundamental charge transport and silicon). Zinc oxide TFTs may face a the electronic structure of zinc oxide lower entry barrier to manufacturing thin films.

Major Accomplishments

• Developed a novel process for fabricating self-patterned organic thin-film transistors via chemical modification of the electrode interface that simplifies device fabrication and may yield significant reductions in manufacturing costs by eliminating subtractive processing steps. • Demonstrated the most correlation to date between molecular design, microstructure, and electronic properties for organic thin-film transistors. • Developed the most advanced capacitance-voltage measurements and analysis techniques for characterizing the contact and channel properties of organic thin-film transistors.

Selected Publications

• D. J. Gundlach, J. E. Royer, S. K. Park, S. Subramanian, O. D. Jurchescu, B. H. Hamadani, A. J. Moad, R. J. Kline, L. C. Teague, O. Kirillov, C. A. Richter, J. G Kushmerick, L. J. Richter, S. R. Parkin, T. N. Jackson, J. E. Anthony, “Contact Induced Crystallinity for High Performance Soluble Acene-Based Transistors,” , vol. 7, pp. 216-221 (2008) • O. D. Jurchescu, B. H. Hamadani, H. D. Xiong, S. K. Park, S. Subramanian, N. M. Zimmerman, J. E. Anthony, T. N. Jackson, D. J. Gundlach, “Correlation Between Microstructure, Electronic Properties and in Organic Thin Film Transistors,” Letters, vol. 92, 132103 (2008) • B. H. Hamadani, C. A. Richter, J. S. Suehle, D. J. Gundlach, “Insights into the Characterization of Polymer-Based Organic Thin Film Transistors Using Capacitance-Voltage Analysis,“ Applied Physics Letters, vol. 92, 203303 (2008) Contact

David J. Gundlach Figure 1. Characterizing the electronic properties of single-crystal organic field-effect (301) 975-2048 transistors in a vacuum cryogenic probe station. [email protected] Image Copyright Robert Rathe

Electronics and Electrical Engineering Laboratory 29 NANOELECTRONIC DEVICE METROLOGY

Summary Description

More than 60 years ago, the Throughout its history, the total metrology package – a set of new invention of the transistor semiconductor industry has constantly tools, tests, and methods for the revolutionized technology for aimed to build information-processing nanoelectronics age – that will help communications, , devices that deliver higher performance enter the transportation, healthcare, and greater information storage marketplace more quickly. Such a large manufacturing, and , as density, while costing less and using task is well suited to NIST's uniquely well as national security and less power. Continuation of this trend broad expertise and experimental defense. The transistor, which is requires new breakthroughs, and the capabilities. the basic building block of industry is looking to move beyond the New computational state variables microelectronics, has been scaled current standard of integrated circuits other than electronic charge (such as to ever smaller sizes until state-of- built using complementary metal- spin and molecular configuration) are the-art integrated circuits contain oxide-semiconductor (CMOS) being investigated in order for future, billions of transistors each of technology. low-power, high-performance which is tens of nanometers in Current CMOS-based transistors are information processing devices to size. Fundamental limitations are now considered a type of reduce the amount of energy per unit being reached for conventional nanoelectronics, with dimensions of a area that is required. The project transistors, and novel computing few dozen nanometers and research partners with key researcher teams devices capable of replacing it as ongoing to shrink them further. But associated with the Nanoelectronics the logic switch are needed. The right now, the main challenge in Research Initiative (NRI) to advance Nanoelectronic Device Metrology moving CMOS forward is making the this visionary, high-risk area of Project aims to develop innovative circuits faster, which involves research. measurements and standards that determining how to regulate their The project has four major goals: to help enable next-generation power consumption. Researchers develop tests and methods to technologies to develop to the aiming to develop the field of accurately measure the electrical point where commercial nanoelectronics are therefore properties of small groups of applications become feasible. The investigating ways to exploit the molecules, ensembles that are the project is targeting critical tools to properties of materials at the nanoscale basis of an emerging class of assess and speed the development in order to achieve this goal. minuscule circuits known as molecular of technologies such as molecular EEEL scientists are involved in a wide electronics; to develop the metrology electronics, memristors, organic range of nanoelectronics research. The for research into silicon-based spintronics, and Si-nanowire goal of the Nanoelectronic Device nanoelectronics; to develop advanced transistors. Metrology Project is a fundamental techniques to measure the very small one. Project scientists are developing a typical of nanoelectronic

30 Electronics and Electrical Engineering Laboratory devices (e.g., nanowire transistors the development of organic and memristors); and to devise spintronics and other alternative measurement techniques to help with technologies.

Major Accomplishments

• Demonstrated that molecular monolayers can be assembled on the same silicon (Si (100)) that is used to manufacture today’s high-performance integrated circuits, a step toward CMOS-compatible molecular electronics. • Developed a “directed self-assembly” approach to fabricate high-performance Si nanowire FETs on the wafer scale, demonstrating that self-assembled nanowires can impact large scale integration. • Combined aspects of molecular electronics and spintronics to design and fabricate a novel device called a "molecular spin-valve." We used a powerful characterization method, inelastic electron tunneling spectroscopy, to study charge and spin transport in this innovative structure.

Selected Publications

• C. A. Richter, H. Xiong, X. Zhu, W. Wang, V. Stanford, W. K. Hong, T. Lee, D. Ioannou, Q. Li, "Metrology for the Electrical Characterization of Semiconductor Nanowires," IEEE Transactions on Electron Devices, Vol. 55, No. 11 (2008) • N. Gergel-Hackett, C. D. Zangmeister, C. A. Hacker, L. J. Richter, C. A. Richter, “Demonstration of Molecular Assembly on Si (100) for CMOS-Compatible Molecule-Based Electronic Devices,” J. Am. Chem. Soc.; (Communication); 130(13) 4259-4261 (2008) • W. Wang, A. Scott, N. Gergel-Hackett, C. A. Hacker, D. B. Janes, C. A. Richter, “Probing Molecules in Integrated Silicon-Molecule-Metal Junctions by Inelastic Tunneling Spectroscopy,” Nano Letters 8 (2), 478-484 (2008)

Figure 1. Loading a molecular electronic sample for electrical characterization. Image Copyright Robert Rathe

Figure 2. Si-nanowire FET: directed self-assembly.

Contact

Curt A. Richter

(301) 975-2082

[email protected]

Electronics and Electrical Engineering Laboratory 31 INFRASTRUCTURE FOR INTEGRATED ELECTRONICS DESIGN AND MANUFACTURING (IIEDM)

Summary Description

In the tightly interconnected but In the highly competitive global composition information (to ensure globally distributed electronics semiconductor and electronics industry, environmental compliance and industry, vast amounts of information the key to survival for companies is their market acceptability). Just as importantly must flow unimpeded and correctly ability to dramatically increase their pace as having the ability to exchange between industry members in order to of innovation, manufacturing, and market information is the requirement that the create and reliably manufacture the share. This is because most electronic information exchange is correct and next-generation electronic products. products debut as a high profit margin understandable. Unfortunately, instead of doing product when first released but rapidly If a product’s information cannot be business using a common set of transition down to mere exchanged between companies or is standards, companies, trade consortia, status. Cell phones are a perfect example accidentally altered in transmission, the and standards organizations have all of this trend where most models typically entire product can be ruined. What created their own standards on how have a 6 to 18 month shelf life before industry needs is a robust IT infrastructure to interact and exchange product being made obsolete by newer models. consisting of standards for collaboration, information. The result is a tangled This means that companies typically only business process integration, and the mess of competing data exchange have one chance to design, manufacture, exchange of technical data. standards where there are few if any and market a new product. Failure on any Unfortunately, due to a variety of reasons industry-wide standards, with some level ( flaw, manufacturing (lack of coordination across industry, lack even having been created for the sole process taking too long, product not of support for standards development purpose of giving a particular allowed in target market, etc.) can result in efforts, and a lack of trust between member an economic advantage. This lost , profit, and future investments. business competitors), industry is far from causes confusion and distrust Few semiconductor and electronics having the uniform set of standards that throughout the industry and impedes companies can survive failure for long. are needed to achieve their goal of fast commerce. The IIEDM project at NIST Industry knows that the key to surviving data exchange and integration. In fact, is uniquely suited to solving this this viciously fast product development with multiple companies, trade consortia, problem due to its researchers' cycle is the need for information and and standards development bodies all technical expertise and neutrality, accurate sharing of data. In designing and working to establish the needed IT which allows industry consortia, producing new products, vast amounts of infrastructure, industry has been left with academic institutions, and standards information need to be exchanged a tangled mess of competing standards bodies to improve their data between industry partners. Examples with no clear idea of which, if any, exchange standards without concerns include product design information standard should be used and supported. of favoritism or bias towards one (necessary to outsource a product’s Project researchers work with industry to particular technology or standard. production across multiple companies and enable the robust IT infrastructure needed multiple countries) and product material to support the electronics industry. Key

32 Electronics and Electrical Engineering Laboratory areas that the project is working on project’s researchers are able to increase include: the ability to accurately describe industry’s participation in standards electronic components and their development projects that traditionally no attributes, how this data is organized and single company will pursue due to its packaged, and how it is accessed and broad-based benefit to industry. In used through a product’s lifecycle (from addition, being outside of industry gives the product design, through its this project a unique ability to survey manufacturing, and, ultimately, to its industry activity and guide efforts to avoid ). Using NIST’s reputation for overlapping standards development and neutrality and technical expertise, the prevent interoperability problems.

Major Accomplishments

• Provided technical expertise and leadership in the development of IPC 1752, the U.S.’s first material declaration standard, which was created to support efforts to prove compliance with Europe’s new restrictions on hazardous materials in electronics. Products failing to comply would be banned from the EU market, negatively impacting the $46 billion dollars of U.S. high-tech exports marketed in Europe. • Chaired the Information Management Systems chapter of the iNEMI industry roadmapping effort, which seeks to identify future technology roadblocks in managing product information. This allows solutions to be developed and in place by the time needed by industry.

Selected Publications

• E. Simmon, J. Messina, K. Brady, "Information Management for Environmental Concerns," FEO MAGAZINE, No. 2 (2008) • E. Simmon, J. Messina, "Improving Environmental Information Handling and Data Exchange within the Electronics Industry," Proceedings of 2008 IEEE International Symposium on Electronics and the Environment, San Francisco, CA (2008) • J. Moyne, Y. S. Li-Baboud, X. Zhu, D. Anand, S. Hussain, "Semiconductor Manufacturing Equipment Data Acquisition Simulation for Timing Performance Analysis," Proceedings of ISPCS 2008 – International IEEE Symposium on Precision Clock Synchronization for Measurement, Control and Communication,” Ann Arbor, MI (2008) Figure 1. The project brings standards development techniques and technologies to the semiconductor industry

Contact Figure 2. will John Messina impact multiple areas outside of (301) 975-4284 manufacturing. [email protected]

Electronics and Electrical Engineering Laboratory 33 KNOWLEDGE FACILITATION

Summary Description

The Knowledge Facilitation EEEL has taken the lead in developing via the NIST external website with no Project spearheads the EEEL several IT applications at NIST that help further action by the researcher required. effort to eliminate paper and to both the researchers and management The project database also interacts with automate manual, labor the progress a project is making the EEEL trip and talk database to report intensive activities. The project toward meeting its defined goals. The EEEL travel and talks given by project staff. Both employs cutting-edge web- project database allows researchers to of those applications were also developed based technologies to develop enter milestones, deliverables, tasks, and by the Knowledge Facilitation Project. custom applications in support cost centers by project and to update their Project staff members are also of efficient EEEL operations. status quarterly. Management can use the developing an RFID inventory application These applications, which are database to monitor progress without for EEEL. Inventories cost the division in developed in house and are not disrupting the researcher, and the labor, as the technical staff members available commercially, researcher can use the database to spend valuable time locating equipment. automate tasks and decrease generate progress reports to outside By marking each piece of equipment with the administrative requirements sponsors. This database is maintained by an RFID tag, coupled with an application of the technical and support fiscal year so a history of the project and its developed by project staff, the inventory staff, while increasing milestones and accomplish ments is can be performed by non-technical staff responsiveness to customers and maintained. This application contains all as often as management requests. The implementing a secure paperless project-related information such as cost savings in technical staff time alone environment. As a result, EEEL funding, milestones, staff, progress, etc. is enormous. scientists are able to spend more for all of the 97 projects in EEEL. Access to With a renewed emphasis on safety, time working in their labs than the data is provided by user roles; i.e., project staff members are developing a working at their computers to division chief, group leader, project leader, safety database to store information fulfill administrative and staff. Each person’s ability to edit about hazards located in each researcher’s requirements. information increases based on his or her laboratory. The database will store As more and more EEEL data are defined role. This database interacts information about , high voltage, stored electronically, project directly with the NIST publications etc., and it will automatically print warning staff members have developed database to report publications the project signs for the laboratory doors. Hazard ways to share the information has produced. The NIST publications data- reports by building and floor will be easily through a variety of reporting base allows researchers to enter their generated, so management can verify mechanisms, minimizing the papers into the editorial review process safety procedures during quarterly safety number of times the data have electronically, and, once the paper is inspections. Project staff members are to be entered. published, the system can make a PDF committed to helping the researchers version of the paper available to the public spend more time in the lab.

34 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed a web-based application in JAVA to initiate, store, and manage the workflow process for all NIST publications. This EEEL application was so successful, it was adopted NIST wide. • Developed the to Support Calibrations (ISSC), which is a structured-query language database-driven application. The ISSC stores all of the administrative, technical, and financial data involved with items calibrated at NIST. • Developed a scheduling and accounting system for the NIST AML Nanofabrication Facility. It allows researchers to schedule time on equipment in the Nanofab and charges them by the time the facility was used. • Developed and demonstrated a inventory application, using RFID technology, for inventory control for EEEL. This will ultimately free researchers from having to do time-consuming inventory assessments. • Developed follow-on application to the ISSC to manage internal NIST calibration data.

Selected Software Applications

• Electronic Project Database

• OLES Body Armor Database

• EEEL Solvency

• Personnel Database

• Trip Database

• Bibliography Database

• RFID Inventory Database

• Cost Center Database Figure 1. Using RFID • Check Standards Database Technology for equipment inventory.

Contact

Kevin Brady

(301) 975-3644

[email protected]

Electronics and Electrical Engineering Laboratory 35 36 Electronics and Electrical Engineering Laboratory OPTOELECTRONICS DIVISION

Optoelectronics is the study of electronic devices that produce, detect, and control light. The mission of the Optoelectronics Division is to provide the optoelectronics industry and its suppliers and customers with comprehensive and technically advanced measurement capabilities and standards, as well as traceability to those standards. We take metrology seriously. In optoelectronics, as in many other fields, metrology is a key part of the industrial infrastructure that establishes competitiveness. Consistently specified products are essential in fair trade, and measurements are a key element in efficient manufacturing. The cost of measurements often ranges between 10 % and 30 % of the cost of producing a product. Advancing the field of optoelectronics metrology is therefore an important task.

The division is comprised of eight projects focused on four major areas: radiometry, , quantum optics, and nanophotonics. Our activities are well-aligned with the national and NIST priorities of measurements and technology for energy, environment, manufacturing, healthcare, physical infrastructure, and . Our focus on a small number of significant technical areas enables us to maximize impact and benefit from collaboration among the projects made possible by our common optoelectronic technology focus.

The division maintains the U.S. national standards for laser power and energy measurements and uses them to provide the broadest range of laser calibration capabilities available anywhere. Each year we perform over 200 calibrations of power- or energy- measuring instruments for more than 50 customers. We also provide artifact calibration standards called Standard Reference Materials. These components provide customers with the capability of performing periodic instrument calibrations traceable to national standards in their own laboratories. We also develop solutions for tomorrow’s critical measurement challenges in nanoscale optoelectronics, the creation and characterization of engineered photon states, quantum information, and optical communications.

The division is well-connected with both public and private stakeholders. We maintain close contact with the optoelectronics industry through major industry associations, such as the Optoelectronics Industry Development Association (OIDA). We also directly gather input from and assist customers in companies and universities. With collaborators, we lead fundamental research in areas such as fiber sources for next-generation atomic clocks, single photonics for ultra-secure communications, and carbon nanotubes for state-of-the-art detector coatings. We also transfer detector technology, trace gas sensing methodology, and other research to the public sector. Finally, we represent NIST to the major domestic and international standards-developing organizations active in optoelectronics – especially the American National Standards Institute (ANSI), the International Electrotechnical Commission (IEC), the International Organization for Standardization (ISO), and the Telecommunications Industry Association (TIA) – and provide impartial technical expertise in their negotiations.

Our intent is to be the preeminent source of optoelectronics metrology in the world. We strive to provide the best optoelectronic measurement services possible and perform the research and development that best enhances measurement sciences in optoelectronics.

Electronics and Electrical Engineering Laboratory 37 DISPLAY METROLOGY

Summary Description

Televisions, computers, and The is a major user set of best practices in critical telecommunications of electronic displays for medical, measurement areas. These areas equipment are merging into automotive, , consumer, include reflection metrology and advanced systems that enable and computational use. The first stray light management (veiling unforeseen applications in three applications require glare, ambient contributions) and many areas, such as stringent testing to ensure the development of transfer (remote learning), adequate performance for standards and devices to facilitate entertainment (3D movies), viewing and interpreting digital direct comparisons of different and medicine (remote images. For example, medical display technologies under different surgery). Displays are radiologists require displays that lighting conditions – from the everywhere – thermal imagers will provide accurate contrast and brilliant daylight in an airplane for firefighters, airplane resolution of digital images; cockpit to the dark automobile cockpits, and your doctor’s correct medical diagnoses depend interior at night. office. To facilitate worldwide upon it. In addition, well-defined In the area of reflection commerce in displays, methods for specification and metrology, EEEL researchers have methods for characterizing verification of display quality are developed quantitative methods display quality are needed to necessary to enable worldwide based upon the bidirectional ensure that a display will commerce of displays. Sound reflectance distribution function. work under the available metrology tools are urgently They are using a three-component lighting conditions – ranging needed in this highly competitive reflection model of specular (with from daylight for cell phone environment of new and emerging a distinct virtual image users to smoky for display technologies to ensure proportional to the luminance of firefighters. To ensure equity quantitative metrics for ), Lambertian (perfectly in the marketplace, comparing the performance of diffuse, luminance proportional to NIST is working with industry emerging technologies. Further, the illuminance), and haze (a to develop standards and universally recognized and diffuse intermediate state of the necessary measurement accepted standard documents are between specular and Lambertian tools to characterize displays needed to provide customers with that is peaked in the specular under a wide variety of the necessary knowledge to make direction but proportional to the conditions. informed purchases for their illuminance). EEEL is extending applications. these techniques to address issues To address these needs, EEEL has related to daylight readability of focused on developing a common displays.

38 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed world-class short course on display metrology. Other NMIs send their staff to NIST to learn about best practices. • Developed methods for characterizing luminance probes for use with high- contrast medical displays, critical for clinical diagnostics. • Published popular consumer guide for purchasing flat panel , featured in Home Theater Magazine. • Led international standards activities; e.g., SID International Committee for Display Metrology.

Selected Publications

• E. Kelley, M. Lindfors, J. Penczek, “Display Daylight Ambient Contrast Measurement Methods and Daylight Readability,” J. Soc. Inf. Display 14, 1019-1030 (2006) • J. B. Dinaburg, F. Amon, A. Hamins, P. Boynton, “Performance of Liquid- Crystal Displays for Fire-Service Thermal-Imaging Cameras,” J. Soc. Inf. Display 16, 703 (2008) • M. Dowell and E. Kelley, “Tricks of the Trade: Tips for Buying Flat Panel Display Televisions,” NCSLI Metrologist, 28-29 (2008)

Figure 1. Reflection measurement apparatus for large flat panel displays. Reflection measurements are critical to the evaluation of display performance under ambient illumination conditions, which can vary from blue illumination on a cell phone to the reflected light from office walls onto a desktop monitor.

Figure 2. Multi-sun-level photoluminescence measurement apparatus under calibration.

Contacts

Edward Kelley Paul Boynton

(301) 975-3014

[email protected]

Electronics and Electrical Engineering Laboratory 39 LASER RADIOMETRY

Summary Description

Accurate characterization Meeting the current and future nanotube coatings, project staff of lasers is important needs of the laser and members have developed a set of to applications such optoelectronics industries requires characterization tools for as communications, medicine, investigation and development of practical measurements of bulk and semiconductor improved measurement methods nanomaterials using non-contact manufacturing, as well and instrumentation for high- probes pioneered at NIST. Existing as laser safety. accuracy laser metrology over a measurement tools are neither This project focuses on wide range of powers, , practical nor useful for current measurements of critical laser and wavelengths. The and future large-scale production parameters, especially laser Optoelectronics Division has of nanomaterials. These tools power and energy. historically used electrically often rely on physical contact Project staff members calibrated laser calorimeters to between the test probe and the participate in national and provide traceability to the SI units material under study. However, international standards for laser power and energy. The physical contact between probes committees for laser safety division has also developed and nanomaterials may alter the and optoelectronic devices. measurement capabilities based material property of interest; e.g., Through research into new on a Laser Optimized Cryogenic differentiating bulk resistance optical materials and Radiometer, which provides an from contact resistance. detectors, the Optoelectronics order of magnitude in accuracy Advanced, cost-effective Division has extended improvement for laser power analytical techniques are needed and improved measurements measurements, compared to so that manufacturers, product of lasers and optical detectors, electrically calibrated radio - developers, and regulatory including development meters. agencies can truly "see" what they of low-noise, spectrally With few exceptions, all of the have. Photons, being massless and flat, highly uniform primary measurement standards chargeless, are an ideal, non- optical detectors; high- for establishing traceability to contact probe. These non-contact accuracy transfer standards fundamental units for radiometry techniques, relying on photon- for optical-fiber and laser are based on thermal detectors. interactions, include power measurements; and Research into optical coatings has resonant-coupled photo - advanced laser systems for led to superior thermal detectors conductive decay, high-Q laser power and energy with absorber coatings consisting dielectric measurements, measurements. of purified carbon nanotubes. To absorption spectroscopy, and support advanced carbon fluorescence.

40 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Completed international comparisons of laser power with , Great Britain, Japan, Mexico, Russia, and Switzerland. • Demonstrated a novel optical detector with spectral response variations less than 1 % over a wavelength range from 600 nm to 1800 nm. • Published absolute reflectance and absorbance values of films, critical for international documentary standards and as input to commercial product development. • Developed critical metrology for high-efficiency, laser-based manufacturing processes.

Selected Publications

• J. Lehman, K. Hurst, A. Dillon, A. M. Radojevic, R. M. Osgood, “Multiwall Carbon Nanotube Absorber on a Thin Film Pyroelectric Detector,” Opt. Lett. 32, 772-774 (2007) • Vayshenker, J. Lehman, D. Livigni, X. Li, K. Amemiya, D. Fukuda, S. Mukai, S. Kimura, Figure 2. Thermal image of a high-energy laser M. Endo, J. Morel, A. Gambon, “Trilateral Optical Powermeter Comparison Between . The targeted red area is a mirror being NIST, NMIJ/AIST, and METAS,” Appl. Opt. Lett 46, 643-646 (2007) heated slightly above room temperature while • K. Ramadurai, C. L. Cromer, J. H. Lehman, K. E. Hurst, L. A Lewis, A. C. Dillon, R. J. illuminated with a 250 mJ laser pulse. Mahajan, “Evaluation of Thermal Threshold of Carbon Nanotubes for Thermal Detector (Photo by Dan King.) Coatings,” J. Appl. Phys. 103, 013103 (2008)

Figure 1. Photograph (right) and scanning electron microscope images (left) of a thin-film pyroelectric detector coated with multi-walled carbon nanotubes. We have observed that multi-walled carbon nanotubes are superior to single-wall carbon nanotubes for a thermal absorber having high absorption efficiency, high damage threshold over a broad wavelength range. (Lehman et al., Opt. Letts., 32, 772-774 (2007).

Figure 3. Flowing water optical power meter (black cone) for optical power measurements of high-power laser sources. (Photo by Chris Cromer.)

Contact

John Lehman

(301) 497-3654

[email protected]

Electronics and Electrical Engineering Laboratory 41 HIGH-SPEED MEASUREMENTS

Summary Description

E-, Web searches, Optoelectronic communications calibrated pulse generators is the text messages, hardware translates electric calibration of and transfers, phone currents into light waves and back other high-speed temporal calls, even wireless calls all again at a pace that can move data waveform measurement systems spend time as pulses of light as fast as 40 gigabits per second — used in the , flashing through fiber-optic a speed great enough to transmit wireless communications, and fiber lines spanning tens, hundreds, full-length digital movies across the optic communications industries. or thousands of miles. country in something over a When combined with the NIST Today's economy relies second. EEEL has pioneered the Timebase Correction Software, on these forms of high-speed high-speed measurement standards engineers can overcome some of communications, and NIST and methods crucial to the the bandwidth limitations of their plays a crucial role in functioning of high-speed test equipment, enabling product providing the means to test communication equipment as well specifications with known the equipment on which these as other vital radar, remote rather than the communications depend sensing, wireless communications, current practice of placing upper by developing novel methods and computer-. limits on signal accuracy, leading for calibrating optical and Through a combination of electro- to needlessly large tolerances in electrical waveforms. optic sampling (EOS) and high-speed components and These methods will enable covariance-based systems. the design and qualification analysis, EEEL calibrates high-speed With the prospect of faster all- of current and next- to be used as electrical optical switching equipment, generation communication pulse generators for characterizing engineers will need a way of networks that is required high-speed test equipment in both measuring light-signal quality, to achieve the goal of true time- and frequency-domains. understanding its inevitable broadband access in every The covariance analysis creates a degradation, and dynamically American community. framework for maintaining the compensating for such impairments correlations in the uncertainties of in the equipment sending the the frequency-domain impedance original signal. To this end, EEEL is measurements and mismatch measuring light signal quality as corrections in the EOS measurements well as various forms of signal so that uncertainties in the time- degradation in work indispensable domain can also be determined. An to next-generation all-optical important application of these networking.

42 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed first traceable electro-optic sampling system to calibrate photodiodes up to 110 GHz. • Demonstrated world’s only calibrated complex frequency response and time- domain impulse response with mismatch corrections and full point-by-point uncertainty analysis in both time and frequency domains thus enabling traceability to new classes of high-speed devices. • Created publicly available software to correct for both random and systematic timebase errors in high-speed sampling oscilloscopes.

Selected Publications

• J. A. Jargon, X. Wu, and A. E. Willner, “Optical Performance Monitoring Using Artificial Neural Networks Trained with Eye- Parameters,” IEEE Photon. Technol. Lett., vol. 21, pp. 54-56 (2009) • P. D. Hale, D. F. Williams, A. Dienstfrey, C. M. Wang, A. Lewandowski, T. S. Clement, D. A. Keenan, “Complete Waveform Characterization at NIST,” Conference on Precision Electromagnetic Measurements, June 8-13, 2008, pp. 680-681 (2008) • D. F. Williams, A. Lewandowski, T. S. Clement, C. M. Wang, P. D. Hale, J. M. Morgan, D. A. Keenan, and A. Dienstfrey, “Covariance-Based Uncertainty Analysis of the NIST Electro-Optic Sampling System,” IEEE Trans. Microwave Tech., vol. 54, pp. 481-491 (2006)

Figure 1. Graphical representation of the Figure 2. A digital optical correlation matrix corresponding to communications signal measured with systematic errors in measuring the waveform linear optical sampling. The gray dots of Figure 1. Light areas show times that are are an "eye" diagram of the signal, highly correlated with each other, while dark which has a four-level phase-sift keying areas show times that are only partially format, dominated by random noise. Figure 3. Calibrated waveform a pulse generator correlated. Knowledge of the covariance The colored dots are obtained by delivers to a 50 Ohm load (top) and the standard matrix, which is closely related to the waveform averaging the eye diagram uncertainty of the voltage at every time (bottom). correlation matrix, allows transformation of with a precision time base to reveal The uncertainty is the square root of the diagonal the uncertainty between the time and individual signal trajectories, allowing elements of the covariance matrix. This frequency domains, when appropriate. The signal to be distinguished measurement is directly traceable to the NIST technique for transforming the uncertainty from noise. electro-optic sampling system through techniques was developed at NIST. developed at NIST.

Contact

Paul Hale

(301) 497-5367

[email protected]

Electronics and Electrical Engineering Laboratory 43 FIBER SOURCES AND APPLICATIONS

Summary Description

Optical frequency combs In 2005, NIST John L. Hall methods are inadequate; however, convert a laser source shared the Nobel Prize in physics project scientists have containing a single frequency for his part in the invention of the demonstrated that it is possible to of light into pulses that optical frequency comb. In the transmit these highly stable include thousands of frequency domain, the of a over 250 km of standard frequencies. This project aims frequency comb is literally a comb , as a first step to a to develop frequency comb of narrow, sub-, optical nationwide fiber-optic distribution technology for a growing list lines, while, in the time domain, of clock signals. of applications. the output is a highly coherent EEEL scientists also have begun to Using a comb working at pulse train with sub-femtosecond explore other applications that optical telecommunications timing . The original comb could benefit from the uniquely wavelengths, project relied on a titanium-sapphire coherent and broadband output of have transmitted laser, but, in the last five years, these comb sources. In the area of signals from next-generation scientists in this project and spectroscopy, they have measured optical atomic clocks across elsewhere have built combs using the coherent optical response of a hundreds of kilometers. They much less expensive commercial molecular gas over 15 THz of have demonstrated how pairs fiber-optic telecommunications optical bandwidth. In laser of combs working together components and are exploring the ranging, they have demonstrated can increase by a factor of promise of using economical -level ranging at one hundred the speed of devices to improve timekeeping, kilometer distances in millisecond trace chemical analysis with chemical analysis, precision timescales. This rapid absolute significant enhancements in ranging, and ranging could support large-scale sensitivity. Frequency combs diagnostics. manufacturing or the future also promise to enable Working with the NIST Time and formation flying of satellite arrays. extremely accurate distance Frequency Division, project Finally, in the area of tele- measurements and to assess scientists have demonstrated that communications, project scientists the quality of high-speed fiber-laser based frequency combs have demonstrated high-resolution telecommunications can support measurements of the measurements of high-speed signals with unprecedented highest performance optical clocks phase-modulated waveforms. Such precision. at fractional frequency measurements could provide novel uncertainties below one part in diagnostic capabilities in next- 1017. At these uncertainties, generation high-speed telecom- current satellite transmission munications.

44 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed first self-referenced phase-locked fiber-based frequency comb source in the 1100 nm to 2200 nm wavelength region to support the most advanced optical clocks. • Demonstrated coherent transfer of high-frequency stability optical signals over 250 km of fiber with a fractional stability of 3x10-16 at 1 s. • Expanded potential applications of fiber frequency combs by demonstrating high-resolution molecular spectroscopy, ranging, and characterization of telecomm modulators.

Selected Publications

• I. Coddington, W. Swann, N. R. Newbury, "Coherent, Multiheterodyne Spectroscopy Using Stabilized Optical Frequency Combs," Phys. Rev. Lett., Vol. 100, No. 013902, pp. 013902-1-013902-4 (2008) • P. Williams, T. Dennis, I. Coddington, W. Swann, N. R. Newbury, "Vector Characterization of High-Speed Components Using Linear Optical Sampling with Milliradian Resolution," accepted for publication in IEEE Photonics Technology Letters. • N. R. Newbury, P. Williams, W. Swann, "Coherent Transfer of an Optical Carrier over 251 km," Opt. Lett., Vol. 32, No. 21, pp. 3056-3058 (2007)

Figure 1. Optical response of hydrogen cyanide (HCN) molecules. Image was obtained directly in the radio- frequency domain by mixing the signals from two fiber combs, one of which passes through the HCN sample and the other serving as a reference. Figure 3. Diagram of Linear Optical Sampling System (top) and the measured and Figure 2. The light traveled a total of 251 km, 76 km around installed fiber in the Boulder phase (bottom) for a 10 Gbit/s phase modulated Research and Administration Network (red line) and 175 km on spooled fiber maintained signal with 1.3 milliradians of phase noise. at NIST. Using an optical feedback technique, we stabilized the light to a Contact fractional stability 6x10-19 Nathan Newbury at 100 seconds. (c) 2008 Google (301) 497-4227 - Map data (c) 2008 [email protected] Tele Atlas.

Electronics and Electrical Engineering Laboratory 45 QUANTUM INFORMATION AND TERAHERTZ TECHNOLOGY

Summary Description

Our nation requires the flow This project has two main focuses – Over the past several years, the of information for the the development of optical photon “Terahertz” portion of this project has banking industry, the , technologies for quantum focused on bolometric detection of and others to be completely information science and technology THz radiation. Initial work on secure. Coding information and the development and application cryogenic detectors has been with single particles of light of terahertz and millimeter-wave extended to antenna-coupled (photons) holds the key to technology and metrology for bolometers operating at room ultimate protection from imaging and spectroscopy. temperature. These detectors provide eavesdropping, guaranteed by In the development of single a rugged, low-cost alternative for the laws of physics. photonics for quantum information homeland security applications; e.g., This project develops devices science and technology, researchers mobile police units or portal scanners and measurements that work closely with the Nanostructure in airports. Researchers have enable world-record-setting Fabrication and Metrology Project on established that imaging in the demonstrations of secure the generation of novel non-classical terahertz frequency range has the communications. states of light and the detection of potential for effectively detecting Sensors that can detect single photons. Currently, EEEL weapons and contraband concealed concealed weapons and investigates the use of nonlinear by clothing. EEEL staff members have explosives under clothing are fibers and nonlinear crystals as a fabricated a focal plane array of critical to homeland security. source of correlated photon pairs or antenna-coupled bolometers and Terahertz imaging systems squeezed light and is manipulating demonstrated best-in-class, real-time are capable of revealing the squeezed light to make imaging. Plans are to continue to objects and chemicals that Schroedinger “Cat” states of light. In explore applications of room- metal detectors cannot, but addition to making non-classical temperature (uncooled) and without the risk that states of light, EEEL researchers build cryogenic antenna-coupled micro- X-rays pose. detector systems that are the best in bolometers and perform side-by-side This project develops the the world at operating at the single imaging of the same scenes with terahertz systems and photon level. Presently, this project is passive and actively illuminated measurements that enable primarily focused on using two terahertz systems to help applications including different superconducting detector settle many outstanding pheno- airport security, technologies – transition-edge menological questions, such as the navigation, and industrial sensors (TES) and superconducting capability of terahertz systems to processing. nanowire single-photon detectors selectively identify specific target (SNSPD). materials.

46 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Demonstrated the highest system detection efficiency for single photons, >95 % at 1550 nm. • Demonstrated, for the first time, time-correlated single-photon counting with superconducting single-photon detectors. • Developed and demonstrated an ultra-wideband, millimeter-wave/terahertz detector array for use in contraband detection (with VTT of ). • Developed and characterized a novel, aqueous blackbody calibration (ABC) source for calibrating optical power in the mm-wave to terahertz frequency band.

Selected Publications

• D. Petrovykh, H. Kimura-Suda, A. Opdahl, L. Richter, M. J. Tarlov, L. Whitman, "Alkanethiols on : Multicomponent Self-Assembled Monolayers," Langmuir, Vol. 22, No. 6 (2006) • D. Petrovykh, V. Perez-Dieste, A. Opdahl, H. Kimura-Suda, J. Sullivan, M. J. Tarlov, F. Himpsel, L. Whitman, "Nucleobase Orientation and Ordering in Films of Single-Stranded DNA on Gold," Journal of the American Chemical Society, Vol. 128, No. 1 (2006) • K. Balss, C. T. Avedisian, R. Cavicchi, M. J. Tarlov, "Nanosecond Imaging of Microboiling Behavior on Pulsed-Heated Au Films Modified With Hydrophilic and Hydrophobic Self-Assembled Monolayers," Langmuir, Vol. 21, No. 23 (2005)

Figure 2. Four tungsten transition-edge sensors with aluminum wiring. The upper two are 25 μm by 25 μm. The lower two sensors are 50 μm by 50 μm.

Contact

Sae Woo Nam

Figure 1. Passive millimeter- (303) 497-3148 wave image of concealed contraband (handgun and [email protected] knife).

Electronics and Electrical Engineering Laboratory 47 NANOSTRUCTURE FABRICATION AND METROLOGY

Summary Description

The photon is the This project develops semiconductor communications and the fundamental particle of light, nanostructures, especially self- traceability of optical power to the analogous to the electron as assembled quantum dots and photon. the fundamental carrier of photonic crystals, for a variety of Quantum-dot-based detectors of . applications including single single photons exhibit linear gain at Project members generate, photonics, laser diodes, and ultralow photon fluxes, which manipulate, and detect single quantum optical metrology. It also enables them to count the number photons, which require develops quantum optical metrology of photons in a pulse of light. The making nanoscale structures based on other sources and photon number-resolving capability a few tens of atoms wide or detectors (not based on of the detector developed by the less. Confined in this manner, semiconductor nanostructures). It Nanostructure Fabrication and the photons and collaborates extensively with the Metrology Project is unique in exhibit “quantum” properties Quantum Information and Terahertz compound-semiconductor-based much different from those Technology Project and with JILA to devices. physical properties exhibited accomplish some of its goals. Quantum dot lasers were initially by larger objects. Semiconductor quantum dot investigated because they were In particular, the uncertainty sources of single photons and expected to have low threshold associated with large numbers entangled photon pairs offer many currents, have high differential of particles can be eliminated, advantages compared to competing gain and modulation bandwidths, and measurement accuracy quantum emitter sources. The and be temperature-insensitive. to the fundamental limit quantum dots can be tailored to Although not all of these can be achieved. emit at specific wavelengths. The have been realized, The single-photon emitters spontaneous emission lifetime is 1 quantum dot lasers have and true photon counters ns, which leads to very high rates of demonstrated some previously developed at NIST enable its single-photon emission. Perhaps unpredicted and unusual behavior. scientists to produce and the biggest advantage of these This project, in collaboration with characterize new quantum sources is that they are easily JILA, has recently demonstrated states of light that will push integrated with high-finesse wavelength bistability in a two- measurement science far cavities, enabling even faster section monolithic quantum dot beyond its current limits over emission and directional output. laser and also a “dark pulse” laser, the next decade. High-speed and high-efficiency a novel pulsed laser in which the single-photon sources are an pulses have lower intensity than important enabler of quantum the DC level.

48 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed a photon-number resolving detector based on quantum dots (Quantum Dot Optically Gated Field Effect Transistor, QDOGFET). • Demonstrated a type of mode-locked laser that produces “dark pulses.” • Demonstrated a bistable, switchable quantum dot laser. • Developed spectral--burning technique to demonstrate that exciton time in a quantum dot is limited only by the spontaneous emission lifetime. • Measured g(3) and g(4), the third- and fourth-order intensity correlation, from a pseudothermal source of light.

Selected Publications

• E. J. Gansen, M. A. Rowe, M. B. Greene, D. Rosenberg, T. E. Harvey, M. Y. Su, R. H. Hadfield, S. W. Nam, R. P. Mirin, “Photon-Number-Discriminating Detection Using a Quantum-Dot, Optically Gated, Field-effect Transistor,” Nature Photonics 1, 585 (2007) • M. Feng, N. A. Brilliant, S. T. Cundiff, R. P. Mirin, K. L. Silverman, “Wavelength Bistability in Two-Section Mode-Locked Quantum-Dot Diode Lasers,” IEEE Phot. Tech. Lett. 19, 804 (2007) • J. J. , M. J. Stevens, R. P. Mirin, K. L. Silverman, “High-Resolution

Spectral Hole Burning in InxGa1-xAs/GaAs Quantum Dots,” Appl. Phys. Lett. 88, 061114 (2006)

Contact

Richard Mirin Figure 1. A scanning electron micrograph of a (303) 497-7955 QDOGFET device used for photon-number resolving [email protected] detection.

Electronics and Electrical Engineering Laboratory 49 SEMICONDUCTOR GROWTH AND DEVICES

Summary Description

At the heart of a DVD player, Compound semiconductor materials tools and devices. A simple example or in the fiber optic system form the basis for the diode lasers, is that the optical emission can be that transmits telephone calls LEDs, photodetectors, and high- used to measure externally applied and data, lies a tiny crystal of efficiency solar cells critical to optical strain. Future devices will extend semiconductor that emits communication, display, data this work on nanowires-as- laser light. That storage, and energy conservation and transistors and light emitters to semiconductor chip has been generation. Many of these semi - include nanowire lasers, produced, or “grown,” in a conductor devices now incor porate applications, near-field optical sophisticated piece of structures with a high degree of probes, oscillators for com - equipment to make it pure strain and nanostructures so small munications equipment, single- and efficient for light that the properties of the devices photon emitters and detectors, and generation and detection. depend on their physical dimensions integration of photonics with This project advances cutting- as well as the bulk materials silicon circuitry. edge research in improving properties. The scientific understanding needed semiconductor crystal growth A major focus in this project is the to engineer these devices will make for devices that generate, growth and processing of GaN use of this project’s in control, and sense light. nanowires for nanometrology and quantum dot and nanowire One emphasis is on precisely device applications. Staff in the nucleation and growth mechanisms, growing nanowires one- project have grown GaN nanowires including the role of strain in thousand times narrower than with catalyst-free molecular beam nanostructures. This project supports a human hair. These epitaxy (MBE) that are strain-free, manufacturing of compound structures hold promise for very low in chemical impurities, and semiconductor devices with the enabling high-efficiency solar usually entirely free of structural world’s only composition standards energy cells and energy- defects. These properties lead to for these materials. EEEL staff also saving lighting to combat our high optical emission intensity, lead a cavity ringdown spectroscopy nation’s dependence on fossil consistent doping behavior, and program that focuses on direct fuel, as well as microscopic high mechanical resonance quality measurement of impurities in the sensors and lasers for the factors, all of which are needed for source gases used in compound early detection and treatment future technical applications that semiconductor manufacturing. of cancer. will surpass GaN thin films in Researchers have achieved sensitivity performance. The nanowire archi- below 50 nmol mol-1 for water in tecture is also a framework for arsine and below 10 nmol mol-1 for inventing new characterization water in phosphine.

50 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Grew and characterized defect-free GaN nanowires, leading to an R&D Micro Nano 25 Award for NIST in 2006. • Developed a comprehensive model for estimating carrier concentration and mobility based on nanowire resistance. • Explained the role of growth parameters in the uniformity of InGaAs quantum dot size and spacing. • Applied, for the first time, cavity ringdown spectroscopy to measure water vapor as a contaminant in arsine and phosphine. • Released AlGaAs composition Standard Reference Materials in 2006.

Selected Publications

• L. M. Mansfield, K. A. Bertness, P. T. Blanchard, T. E. Harvey, A. W. Sanders, N. A. Sanford, “GaN Nanowire Carrier Concentration Calculated from Light and Dark Resistance Measurements,” submitted to the Journal of Electronic Materials (2008) • K. A. Bertness, A. Roshko, L. M. Mansfield, T. E. Harvey, N. A. Sanford, “Mechanism for Spontaneous Growth of GaN Nanowires with Molecular Beam Epitaxy,” Journal of Crystal Growth, Vol. 310, 3154-3158 (2008) • S. M. Tanner, J. M. Gray, C. T. Rogers, K. A. Bertness, N. A. Sanford, “High-Q GaN Nanowire Resonators and Oscillators,” Applied Physics Letters, Vol. 91, 203117 (2007)

Figure 1. Scanning electron microscopy picture of GaN nanowires Contact grown with catalyst-free MBE, with insert showing Kris Bertness nanowire tips. Note the hexagonal cross-section, (303) 497-5069 consistent high aspect ratio, and flexibility of [email protected] nanowires.

Electronics and Electrical Engineering Laboratory 51 OPTICAL MATERIALS METROLOGY

Summary Description

The 21st century has It is internationally recognized that position since EEEL-grown nano- heightened needs for LED-based solid-state lighting wires are proven to be some of the conserving energy, producing using III-nitride semiconductors best in the world, and NIST has clean energy at low cost, and (GaN, AlGaN, InGaN) is poised to developed new metrology methods providing safety and security significantly reduce energy to analyze these nanostructures. at home and abroad. To fully demand for the 21st century. EEEL staff can also grow nanowires optimize energy-efficient Illumination consumes approxi - on silicon substrates, thus enabling lighting and displays, next- mately 30 % of the U.S. energy numerous possibilities in new generation solar cells, and budget. Due to various comp - device integration. Recently, sensors, NIST scientists are lications, conventional planar LEDs project staff teamed with a DARPA measuring the critical made from these materials are sponsored “iMINT” University properties of optical materials. inherently inefficient. Moreover, Focus Center on nanotechnology. Especially important are nano- the planar morphology also results Of 11 such Centers now sponsored engineered structures for new in low-light extraction efficiency. by the DARPA MTO office, DARPA technologies, since the There is much room for improving has publicly recognized NIST’s fundamental properties of LEDs in order to meet the looming progress in GaN nanowires as one nanostructures are not the worldwide demands on reduced of the 3 most significant outcomes same as those for bulk lighting costs in the face of of all 11 Centers. The dense materials. This project has mounting energy costs. nanowire morphology also enables made remarkable advances in NIST scientists found that the GaN improved light collection effi - developing measurement tools is fundamentally superior when ciency. Recent advances include and methods for optical grown as nanowires instead of starting work to use nanowires for materials that enable planar films. They also quickly improving photovoltaic devices as enhanced products. A realized that dense nanowire well. particular focus is on arrays would enable LEDs with Nanowire LEDs and lasers are also semiconductor nanowires, a greatly improved light extraction developed for new active-tip near- breakthrough technology efficiency. These findings, con- field scanning optical microscopy offering superior capabilities clusions, and motivations aimed at (NSOM) tools for metrology. for future-generation developing nanowires for LED Additionally, EEEL researchers are microscopes, lighting, illumination technology have been working on the application of photovoltaics, cell phones, and arrived at independently by nanowires for cancer research and other electronics. competing research groups around advanced sensors for biological the world. EEEL is in a strong and chemical agents.

52 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Demonstrated the first core-sleeve nanowire heterostructures employing MBE-grown Si-doped cores and HVPE-grown Mg-doped sleeves. • Demonstrated the best measurement to date for the surface recombination velocity of GaN. • Demonstrated the best GaN nanowire Metal-Semiconductor Field Effect Transistor (MESFET) devices to date. • Demonstrated the use of steady state and transient photoconductivity to estimate carrier concentration, mobility, and capture cross section for nanowires. • Demonstrated nanowire UV detectors sensitive to only a few hundred photons per second.

Selected Publications

• B. Schlager, K. A. Bertness, P. T. Blanchard, L. H. Robins, A. Roshko, N. A. Sanford, “Steady-State and Time-Resolved Photoluminescence from Relaxed and Strained GaN Nanowires Grown by Catalyst-Free Molecular-Beam Epitaxy,” Journal of Applied Physics 103, 124309 (2008) • P. T. Blanchard, K. A. Bertness, T. E. Harvey, L. M. Mansfield, A. W. Sanders, N. A. Sanford, “Metal-Semiconductor Field Effect Transistors (MESFETs) Made from Individual GaN Nanowires,” IEEE Transactions on Nanotechnology (to be published, 2008) • S. M. Tanner, J. M. Gray, C. T. Rogers, K. A. Bertness, N. A. Sanford, “High-Q GaN Nanowire Resonators and Oscillators,” Applied Physics Letters 91, 203117 (2007)

Figure 1. GaN nanowire MESFET shown in (a) view and (b) tilted. Note hexagonal shape of the underlying nanowire as revealed in the overlaying gate contact. Nanowire grown by MBE at NIST-Boulder. Graph illustrates operation of MESFET device.

Contact

Figure 2. Core-sleeve p-n GaN nanowire Norman A. Sanford heterostructure. n-type Si-doped core and p-type Mg-doped sleeve are indicated. (303) 497-5239 Core grown by MBE at NIST-Boulder, sleeve subsequently overgrown by HVPE at [email protected] NIST-Gaithersburg.

Electronics and Electrical Engineering Laboratory 53 54 Electronics and Electrical Engineering Laboratory QUANTUM ELECTRICAL METROLOGY DIVISION

The Quantum Electrical Metrology Division unites fundamental electrical metrology and leading-edge quantum-based measurement research to create a dynamic organization with a mission to lead quantum electrical metrology into the future. The division consists of three groups: Fundamental Electrical Measurements, Applied Electrical Metrology, and Quantum Devices. The first two groups are located in Gaithersburg, MD, and boast of a proud 100-year history of precision electrical metrology. The Quantum Devices Group located in Boulder, CO, brings a 35-year history of creating world-leading quantum-based standards and measurement systems. The division works to provide the world’s best electrically based measurements and standards.

The project descriptions that follow give a detailed description of the work underway in the division. The research falls into three general categories. The division has the responsibility to realize and advance our understanding of the fundamental electrical “units,” including the (both DC and AC), the ohm, and the farad. This work also extends to measuring fundamental constants, with world-leading work on measuring Planck’s constant through electrical measurements using a balance and new work measuring Boltzmann’s constant through electrical (Johnson) noise. The division also provides U.S. industry and other National Metrology Institutes (NMIs) with connection to the electrical units through calibration services and measurement expertise. This includes interlaboratory comparisons and more recently the creation and dissemination of quantum-based electrical standards that allow the highest level of measurement precision to be achieved outside of NIST. Finally, the division uses its expertise in electrical measurements and quantum effects to develop new measurement methods and systems that extend our capabilities into new regimes, such as quantum voltage systems, quantum computing and quantum limited measurements, and quantum sensors for electromagnetic radiation from microwaves through gamma rays.

The division has a staff of about 120, which includes government employees as well as guest researchers, post-doctoral associates, contractors, and graduate and undergraduate students. With facilities on both the Gaithersburg and Boulder campuses, the division has far-reaching ties with universities, government agencies, other NMIs, and U.S. industry. The division’s outreach, which also includes visiting industrial and other sites, attending and sponsoring conferences, and hosting numerous visitors at both campuses, greatly increases the impact and dissemination of our work.

Electronics and Electrical Engineering Laboratory 55 QUANTUM VOLTAGE SYSTEM DEVELOPMENT AND DISSEMINATION

Summary Description

Accurate representation of In 1990, an international agreement the uniformity of voltage measure- the volt and precise redefined the volt in terms of the ments. One key development at NIST techniques for measuring voltage generated by a superconduc- is the programmable Josephson voltage are essential to the ting integrated circuit developed voltage standard (PJVS) system, electrical and electronics jointly at NIST and the Physikalisch- which can provide desired voltages industries. Technische Bundesanstalt (PTB), with an uncertainty better than a Determining how to do this Germany's NMI. The circuit contains few parts in a billion. PJVS replicas throughout the U.S. with thousands of Josephson junctions, are used at NIST and throughout the extraordinary accuracy is each one a sandwich consisting of an world to provide voltage calibrations one of the main roles insulating layer between two for a variety of applications, of EEEL. superconducting segments and particularly that This is accomplished by having a typical thickness of a few measure other electrical units. The developing new quantum hundred nanometers. system is regularly used in the NIST standards using Josephson Current will flow across a Josephson voltage calibration lab and is also junctions, superconductor- junction despite the insulating layer, being implemented in a novel electric based devices whose and, with alternating current (ac), a power calibration system that will quantum behavior makes voltage develops across the junction provide the them perfect frequency-to- that is exactly proportional to the ac with the world's most precise voltage converters. EEEL frequency. This relationship depends electrical standards, which, in turn, scientists are using this only on fundamental constants of support the reliable operation of the property to create quantum physics and does not electrical power grid. extremely accurate DC and depend on the physical properties of Project scientists have also made AC voltage standards and the junction, such as its dimensions substantial improvements to the also to develop novel or environmental conditions like process of accurately transferring a methods for the precise temperature. Josephson junctions, fundamental standard to end users. measurement of other as perfect frequency-to-voltage For example, we have developed a fundamental electrical converters, provide a quantum basis portable, compact Josephson voltage quantities. for a voltage standard because standard (CJVS) that scientists can frequencies can be defined with carry with them to compare Josephson enormous precision. voltage systems in different Josephson voltage standard systems geographic locations. The CJVS have been deployed around the decreased end-user uncertainty by a world since 1990, greatly improving factor of 10 or better.

56 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed an ac Josephson voltage standard (ACJVS) that provides the most accurate ac voltage measurements ever made. • Developed a protocol to successfully compare the NIST Compact Josephson Voltage Standard (CJVS) with the JVS of National Research Council (NRC) Canada. • Performed a direct JVS comparison with Lockheed Martin Mission Services in Denver and found a difference between the two systems of a few parts in 1010, a result that supports traceability of SI units for U.S. industry and other government agencies.

Selected Publications

• Y. Tang, “Application of NIST Compact Josephson Voltage Standard for Intercomparison,” Proceedings of International Conference on Advances in Metrology 2006, Dec.11 -16, 2006, New Delhi, (2006) • S. K. Jaiswal, J. Sims, and Y. Tang, “Characterization of a Low Thermal Scanner for Automatic Voltage Measurement with the NIST Josephson Voltage Standard,” Measurement Science Conference Proceedings, January 22 - 26, 2007, Long Beach, CA (2007) • T. E. Lipe, J. R. Kinard, Y. Tang and J. E. Sims, “Improvements in the NIST Calibration Service for Thermal Transfer Standards,” NCSLI MEASURE, Vol. 2, No. 1, pp. 70-74 Figure 1. Set up the direct JVS comparison between (2007) the NRC JVS, Canada, and NIST compact JVS.

Figure 3. NIST provided a link for Centro Nacional de Metrología (CENAM) to Bureau International des Poids et Measures (BIPM) via a JVS comparison (notice that the pink point representing the CENAM measurement has one of the best links to BIPM).

Figure 2. ACJVS system installed at NIST- Gaithersburg.

Contact

Thomas Lipe

(301) 975-4251

[email protected]

Electronics and Electrical Engineering Laboratory 57 METROLOGY OF THE OHM

Summary Description

Resistance standards traceable to The Ohm Project has been a development of improved NIST provide references for leader in providing internationally standards and techniques for measurements of current at levels consistent resistance standards better agreement between from 2000 A to below 1 pA and are that are readily available to primary references. used to support a wide variety of support the scientific and The project collaborates in impedance, temperature, strain, industrial foundations of the U.S. research on nanometer scale and power measurements. This economy. Through this very broad single-electron devices project develops the technology of customer base, the activities of designed as biometric sensors, quantum electrical measurements the project enable cost-effective and two members participate in including the world’s best high- electrical measurements at NIST the new Quantum Conductance resistance standards and and at more than 300 U.S. sites, Project that aims to develop superconducting quantum leading to improved performance quantum Hall resistance (QHR) interference device ()-based of products and services in a devices from graphene. Project scaling techniques. EEEL maintains competitive world environment. staff members pursue close working relationships with The resistance calibration service scientific breakthroughs to researchers in other leading NMIs brings a yearly income to NIST of maintain accurate local and successfully completed 2 several hundred thousands of representations of the unit bilateral comparisons with the dollars as well as supporting over (conventional standards) and Bureau International des Poids et a dozen other calibration areas. to develop improved quantum Measures (BIPM) and piloted 5 Project staff members provide metrology, including the recent international key comparisons in extensive customer contact and introduction of resistive- the past 10 years. This leadership consultation on topics including winding cryogenic current has resulted in collaborative teraohmmeter measurements, the comparators (CCCs) that research to develop and deploy characterization processes used enable stable SQUID operation sophisticated multi-function, high- with resistive shunts at very high with improved current precision, and low- current levels, and power loading sensitivity. This advance was cryogenic current comparators measurements to support a recent combined with a two-terminal (CCCs) of a new NIST design, which Air Force . Project CCC bridge design that NIST have been installed and tested at scientists work in the U.S. and developed in the 1970s, and NIST and are being installed at international communities, provides the world’s only direct NMIs in Argentina, Australia, including support for CCC scaling from the QHR to and Mexico. comparisons at low, moderate, resistance values from 100 k to and high resistance levels and 100 M and above.

58 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Piloted SIM Key Comparisons at 1 Ω, 1 MΩ, and 1 GΩ; developed analysis to link Systema Interamericano de Metrología (SIM) NMIs to the international community. • Automated and reported 1000 V dual-calibrator bridge measurements using fully guarded robotic actuators. • Developed CCCs for scaling up to 1 GΩ with multiple links to the QHR standard; disseminating the measurement techniques to three other NMIs. • At CPEM08, presented CCC work, SIM results, and teraohmmeter . Collaborated on two papers presented by other NMIs. • At NCSLI-2008, presented papers on power loading in 1 Ω and teraohmmeter procedures.

Selected Publications

• R. E. Elmquist, D. G. Jarrett, N. F. Zhang, “SIM RMO Comparison Report; 1 Ω, 1 MΩ, and 1 GΩ,” submitted to BIPM, to be published in Metrologia Tech. Supp. (2008) • G. R. Jones and R. E. Elmquist, “Power Loading Effects in Precision 1 Ω Resistors,” NCSLI Conf. Proc., August 3-7, 2008. Extended version accepted for NCSLI Measure (2008) • D. G. Jarrett, M. E. Kraft, I. Castro, B. Degler, M. Evans “Procedures for the Traceability of High-R esistance Standards Using a Teraohmmeter,” NCSLI Conf. Proc., August 3-7, 2008. Extended version accepted for NCSLI Measure (2008)

Figure 2. Guest Researcher Dr. F. Figure 3. Summer Undergraduate Research Hernandez (CENAM, Mexico) tests Fellowship researcher A. Mercado helps Figure 1. Guest Researcher Marcos Bierzychudek one of four high-resistance CCC develop a characterization process for insu- (INTI, Argentina) with R. Elmquist and M. Kraft systems constructed in 2008. lating materials to be used in a NASA probe. setting up a CCC cryostat in the AML Resistance lab.

Contact

Rand Elmquist

(301) 975-6591

[email protected]

Electronics and Electrical Engineering Laboratory 59 QUANTUM CONDUCTANCE/ GRAPHENE-BASED QUANTUM METROLOGY

Summary Description

Graphene is a new material Progress in fundamental electrical thus NMIs currently disseminate with truly extraordinary standards and electronics is usually resistance through artifact standards. electronic properties that has incremental and based on brute force These have limited accuracy and are great potential in many areas engineering with sporadic episodes inherently unstable, resulting in time where conventional materials of . Graphene represents consuming and costly calibrations. are running into obstacles. one of these rare opportunities to New graphene-based QHR standards Although conceptually dramatically improve measurement with higher-temperature operation graphene is an unrolled capabilities by utilizing a completely have the promise to greatly improve carbon nanotube (CNT), new scientific principle. However, the dissemination of quantum-based graphene transcends the application of the truly unique resistance metrology to customers. limitations of CNTs by characteristics of graphene requires In microelectronics, it is well known offering the potential to measuring the physical properties and that the continuation of Moore’s Law fabricate complete systems developing new fabrication methods. is already facing major challenges in entirely out of graphene, EEEL’s efforts are currently focused power management and is being ranging from the macro to on developing graphene to advance confronted by the discreteness of nanoscale. The opportunities NIST’s core mission – specifically, the matter itself. The U.S. semiconductor for both exciting new science development of intrinsic quantum industry spends billions of dollars to and important applications electrical standards and metrology to make incremental advances and have led to an explosion enable the development of innovative desperately needs technology that of research on graphene future electronics. transcends CMOS limitations. The at universities, domestic and Since the first quantum Hall major semiconductor industries have foreign national labs, and resistance (QHR) standards were established consortia such as the industrial labs. developed over 25 years ago, Nanoelectronics Research Initiative The goal of the Quantum fabrication of improved GaAs- (NRI) to direct various laboratories Conductance Project is to GaAlAs heterostructures has been a (academic, national, and corporate) develop graphene metrology goal of leading National Metrology to come up with visionary solutions to for intrinsic electrical Institutes (NMIs) around the world; the foreshadowed limitations in standards, specifically near- however, they are consistently in silicon. Graphene promises to be one room-temperature short supply because of the difficulty of these potential solutions, and we quantum Hall resistance in producing even moderate quality will exploit the new opportunities for standards. QHR standards. Operating today’s discovery offered by graphene that QHR devices requires extensive specifically apply to electrical cryogenic equipment and expertise; metrology.

60 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Organized collaborative research program on graphene with other NIST Laboratories and leading U.S. research groups.

• Fabricated exfoliated graphene on Si/SiO2 substrate for testing. • Fabricated first graphene devices at NIST in the Center for Nanoscale Science and Technology (CNST). • Measured external collaborator’s graphene quantum resistance standard against national resistance standards to 3 %.

Selected Publications

• D. Petrovykh, H. Kimura-Suda, A. Opdahl, L. Richter, M. J. Tarlov, L. Whitman, "Alkanethiols on Platinum: Multicomponent Self-Assembled Monolayers," Langmuir, Vol. 22, No. No. 6, (2006) • D. Petrovykh, V. Perez-Dieste, A. Opdahl, H. Kimura-Suda, J. Sullivan, M. J. Tarlov, F. Himpsel, L. Whitman, "Nucleobase Orientation and Ordering in Films of Single- Stranded DNA on Gold," Journal of the American Chemical Society, Vol. 128, No. 1, (2006) • K. Balss, C. T. Avedisian, R. Cavicchi, M. J. Tarlov, "Nanosecond Imaging of Microboiling Behavior on Pulsed-Heated Au Films Modified With Hydrophilic and Hydrophobic Self- Assembled Monolayers," Langmuir, Vol. 21, No. No. 23, (2005)

Figure 1. Graphene Hall bar developed at NIST by undergraduate students.

Figure 1. Graphene Hall bar developed at NIST by undergraduate students.

Contact

David Newell

Figure 2. Graphene Hall (301) 975-4228 plateaus measured with respect to national [email protected] standards.

Electronics and Electrical Engineering Laboratory 61 AC-DC DIFFERENCE

Summary Description

Extremely accurate The use of thermal converters for ac adding more and using measurements of an voltage metrology was introduced by the thermoelement at a reduced input unchanging voltage signal Frank Hermach at NIST in 1952. The amplitude. The resulting device, the can be made relatively basic thermal converter is a thermo- Multijunction Thermal Converter routinely using a quantum element, consisting of a (MJTC), is the most accurate means of voltage source. However, positioned at the midpoint of a heater measuring AC voltage and current at for many real-life wire, enclosed in an evacuated bulb. voltages above 500 mV and currents up applications, the accurate The thermoelement senses the heat to 50 mA; uncertain ties of about 5x10-7 measurement of a varying generated by an electrical signal applied or less are possible in the audio electrical signal is a more to the heater. By comparing the heating frequency. Unfor tunately, tradi tional important and challenging effect of an unknown AC signal to that MJTCs made with wire are difficult to measurement need. The of the average of both polarities of a make and nearly impossible to obtain. NIST AC-DC Difference known DC signal, the Root Mean To address this problem, NIST is presently Project provides U.S. Square (RMS) AC quantity may be making MJTCs using semiconductor industry with the essential measured in terms of the known DC fabrication techniques. These devices fall link between ac and the quantity, giving the AC-DC difference into two broad categories; one type of corresponding DC electrical of the thermal converter. The traditio - MJTCs is designed for high-frequency AC standards via a world-class nal thermoelement has an input voltage voltage metrology, the other for high- calibration service, and, of a few or an input current of a current AC metrology. The high- through cutting-edge few milliamperes, with a best frequency MJTCs (Fig. 1) are fabricated research into new AC-DC uncertainty of about 1 μV/V or μA/A on quartz substrates, for reduced difference measurement over the frequency range from 10 Hz to dielectric loss, and are predicted to have techniques, employs both 1 MHz. In combination with a precision very small AC-DC differences up to 100 quantum standards and or , the thermal converter MHz at a few volts. The high-current standards fabricated in is commonly used at voltages up to MJTCs (Fig. 2) have very large heater novel ways. 1000 V and currents up to 100 A and, in structures capable of taking currents up combination with circuits, is to 1 A. We plan to up to eight of used at voltages as low as 2 mV. these high-current MJTCs in a single The fundamental errors in thermo- module to achieve a 10 A current elements are thermoelectric errors, converter. Initial results are very encoura- produced when a current flows through ging, and we anticipate using both of a temperature gradient. These thermo- these MJTCs in our measurement services electric errors may be reduced by before the end of the year.

62 Electronics and Electrical Engineering Laboratory In addition to new artifact standards, in uncertainties obtained using traditional collaboration with the Quantum scaling techniques. The AC Josephson Voltage Project, we are developing a Voltage Standard (ACJVS, Fig. 3) quantum standard for AC voltage, promises unprecedented reductions in based on pulse-programmable uncertainty over its operating range of Josephson Junctions. We have already 2 mV to about 275 mV and, coupled provided a quantum-based calibration with MJTCs, should allow us to to a customer with reductions in substantially reduce the uncertainties uncertainty of as much as 98 % over for AC voltage metrology.

Major Accomplishments

• Fabricated prototype multijunction thermal converters based on quartz substrates for AC voltage measurements up to 100 MHz. • Fabricated prototype multijunction thermal converters based on silicon substrates for AC current measurements up to 1 A. • Began dissemination of AC voltage based on ACJVS, providing the most accurate calibrations of AC-DC difference ever made. • Reduced current converter uncertainties at 100 A and 100 kHz from about 1200 μA/A Figure 1. Photograph of quartz-based to about 200 μA/A using NIST-built two-stage current transformers and shunts. multijunction thermal converter.

Selected Publications

• T. E. Lipe, J. R. Kinard, Y. Tang, S. P. Benz, C. J. Burroughs, P. D. Dresselhaus, “Thermal Voltage Converter Calibrations using a Quantum AC Source,” Metrologia, vol. 45, pp. 275-280 (2008) • P. S. Filipski, J. R. Kinard, T. E. Lipe, Y. Tang, S. P. Benz, “Correction of Systematic Errors Due to the Voltage Leads in AC Josephson Voltage Standard,” in CPEM 2008 Digest, pp. 598-599, CPEM 2008, Broomfield, CO (2008) • L. Scarioni, T. E. Lipe, J. R. Kinard, “Design and Fabrication of MJTCs on Quartz Substrates at NIST,” in CPEM 2008 Digest, pp. 648-649, CPEM 2008, Broomfield, CO (2008)

Figure 2. Photograph of 1 A MJTC current converter.

Contact

Thomas E. Lipe

(301) 975-4251 Figure 3. ACJVS system installed [email protected] at NIST-Gaithersburg.

Electronics and Electrical Engineering Laboratory 63 FARAD AND IMPEDANCE METROLOGY

Summary Description

Accurate capacitance The primary facility for connecting mer techniques and modern Digital measurements are essential for the U.S. legal system of electrical Signal Processor (DSP) techniques electronic systems and sensors. units to the international system of has the potential to extend our This project aims to provide units is the NIST calculable expertise over a much wider the world’s best basis for , with which the measure- . accurate impedance ment of capacitance is effectively Consistency between resistance and measurements by tying achieved through a measurement of impedance measurement services the U.S. legal system of length. Both the calculable capacitor from NIST is expected by the electrical units to the and the chain of high-precision instrumentation industry and International System of Units measurements that transfers the SI DOD laboratories. An improved (SI) through the realization of unit to the calibration laboratories is resistance-capacitance (RC) link is the SI unit of capacitance. maintained, improved, and com - also needed to realize the farad This work also forms the pared with other National Metro - from the QHR standard, if the foundation of NIST’s logy Institutes to ensure measure- proposed redefinition of the SI measurement services for ment consistency on an interna - occurs in the near future, and to , ensuring a tional level. advance basic research such as sound metrological basis for Over the last few decades, NIST has closing the quantum metrology impedance measurements, both successfully invested in two key triangle. nationally and internationally, quantum representations of Development of wideband and ensuring that the claims of electrical quantities; both the impedance measurement services measurement accuracy by U.S. Quantum Hall Resistance (QHR) and requires reference standards that industries are recognized and Josephson Voltage standards have can be characterized over the accepted worldwide. now achieved measurement uncer - impedance and frequency ranges of The need continues for a better tainties approaching parts in 109. interest. NIST has developed a representation of capacitance These quantum standards, however, system to characterize commercial and also for better calibration represent only a few points in a four-terminal-pair capacitance tools at NIST with which multi-dimensional world of elec- standards from 1 pF to 1 nF over the researchers can objectively trical measurements. The crucial link frequency range from 1 kHz to 10 verify claims of improved between the fundamental electrical MHz. A bootstrapping technique performance specifications, to standards and commercial electronic using an LCR meter and an inductive achieve consistency and help instrumentation is provided by can extend the avoid technical trade barriers. precision ac measurement stan- characterization to higher-valued dards. A combination of transfor- capacitance standards up to 10 μF.

64 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed a DSP-based signal generator that can be phase and frequency locked to a Josephson source, enabling the development of a quantum electrical power standard. • Developed concept for new calculable capacitor based on laser frequency combs. • Developed a programmable capacitance standard to provide capacitance values from 100 pF to 10 µF with a resolution of 1 pF. • Orchestrated and led a capacitance key comparison for many countries in South, North, and Central America.

Selected Publications

• B. C. Waltrip, B. Gong, T. L. Nelson, C. J. Burroughs, A. Rüfenacht, S. P. Benz, P. D. Dresselhaus, Y. Wang, “Ac Power Standard Using a Programmable Josephson Voltage Standard,” IEEE Transactions on Instrumentation and Measurement (2009, accepted) • Y. Wang, R. D. Lee, L. Lu, J. Lawall, A. Chijioke, “Next-Generation Calculable Capacitor Using a Tunable-Laser Interferometer,” Digest of Conference on Precision Electromagnetic Measurements (CPEM 2008), Broomfield, Colorado (2008) • R. D. Lee, Y. Wang, G. J. FitzPatrick, “3-d Field Simulation to Design a Calculable Capacitor,” Digest of Conference on Precision Electromagnetic Measurements (CPEM 2008), Broomfield, Colorado (2008)

Figure 1. Setting up an automated system Figure 2. Performing a special test for for determining the frequency a four-terminal-pair capacitance dependence of fused-silica . standard.

Contact

Yicheng Wang

(301) 975-4278

[email protected]

Electronics and Electrical Engineering Laboratory 65 ELECTRONIC KILOGRAM

Summary Description

The unit of mass is still NIST has led the world since 1998 of mass, time, length, voltage, defined for the world by a with three consistent results for and resistance are based on in- 1 kg lump of metal kept in the determination of Planck’s lab peripheral systems: mass Paris, . This artifact constant (a fundamental constant artifacts, GPS, laser interfero- mass standard is suffering related to mass). The most recent meter, Josephson array volt from 120 years of wear and NIST value reported in 2005 has system, and quantum Hall contamination, so its value the lowest uncertainty so far, at 36 calibrated standard resistor. over time is becoming parts in 109. Two results from the Precise measurement, calibration, uncertain at several parts National Physical Laboratory (NPL) and other instrumentation issues in 108. While this is a very in England and one from the must be well characterized, which small amount of change, it Avogadro International Con- is why this type of is has great implications for sortium have varied by 300 and best and only performed at deterring the values of 1000 parts in 109, respectively. This national standards laboratories. science’s fundamental shows that significant progress has The International Committee for constants. As a potential been made since the first NPL and Measures (CIPM) has replacement, the Electronic result in 1988, but also shows how recommended a redefinition when Kilogram Project compares difficult and complicated this the experiment proves its the energy in power experiment is. feasibility with several labs generated by mechanical Four international laboratories reproducing a consistent result and electrical means. besides NIST are working with the within the present NIST uncer - Einstein’s famous same technique. In the tainty. With the next opportunity E=mc2 relates this energy experiment, a mass balance uses occurring in 2011, the race is on to measurement to mass. The a precisely aligned induction coil improve the experiments and electronic kilogram will in a high-stability magnetic field, trigger a change in the define mass in terms of where a current applied to the International System of Units (SI) quantum mechanical coil provides an electromagnetic that will provide a quantum-based systems similar to the force in opposi tion to the matrix of units for the foreseeable second (atomic clocks) and gravitational attraction on a mass future, permanently stabilizing the meter (laser standard. As a necessary and both scientific measurements and wavelength), which are all complementary measurement, commercial standardization in unchanging in time. the coil is moved to generate a production and trade of electrical, voltage while recording the coil mass, and force measurement velocity. The reference quantities equipment.

66 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Reported the lowest uncertainty in the world of 36 x 10-9 on a value of the Planck constant in 2005 that was consistent with original value reported in 1998. • Publications of April 2005 Metrologia paper sparked CIPM decision to consider redefinition of kilogram.

Selected Publications

• R. Steiner, E. Williams, R. Liu, D. Newell, “Uncertainty Improvements of the NIST Electronic Kilogram,” IEEE Trans. on Instrum. and Meas., vol. 56, no. 2, pp. 592-596 (2007) • M. Mills, P. J. Mohr, T. J. Quinn, B. N. Taylor, E. R. Williams, “Redefinition of the Kilogram, , Kelvin and Mole: a Proposed Approach to Implementing CIPM Recommendation 1 (CI-2005),” Metrologia, vol. 43, no. 3, pp. 227–46 (2005) • M. Mills, P. J. Mohr, T. J. Quinn, B. N. Taylor, E. R. Williams, “Redefinition of the Kilogram: a Decision Whose Time Has Come,” Metrologia, vol. 42 no. 2, pp. 71-80 (2005)

Figure 1. Artifact International Prototype Kilogram (IPK).

Figure 2. NIST Electronic Kilogram.

Figure 3. Time comparison of scatter in the IPK copies versus the present scatter in NIST e-kilogram data.

Contact

Richard Steiner

(301) 975-4226

[email protected]

Electronics and Electrical Engineering Laboratory 67 ELECTRIC POWER METROLOGY AND THE SMART GRID

Summary Description

Our country's way of life Power outages are at a minimum traditional depends on the electric power an inconvenience, but extended technologies (such as wind and distribution system. Keeping periods without power can be life- solar) that may introduce the national electric grid in threatening; e.g., to patients in distortions into the flow of power good working order – and and during extreme delivered to customers. EEEL is ensuring power is measured weather. of the U.S. developing systems to characterize accurately and billed fairly – electric power industry has the distortions and verify that requires a set of standards for complicated the task of ensuring meters can still operate accurately electric power measurements. the dependability of the nation's even when these distortions are NIST is deeply involved in complex power infrastructure. present. developing and maintaining NIST performs invaluable research Modern society's embrace of more these standards. Our efforts that supports reliable power efficient electrical devices is also include devising metrology delivery, public safety, and driving new standards research. To that allows new technologies accurate pricing of electric power. encourage reductions in electric to connect into existing Ironically, modern technological power consumption, the U.S. power production and advances are making this task even Department of Energy (DOE) delivery systems, as well as more difficult. For example, designates minimum efficiencies standards that protect the sensors and actuators used to for electrical equipment, such as infrastructure from potential control the operation of electric power transformers and electric dangers introduced by power systems are now widely motors. NIST advises DOE by deregulation. This project's connected via modems and the developing technically sound work also supports the Web, but because they are sampling strategies and realization of the Smart Grid, designed for speed and other instrumentation for testing these the future model of the U.S. functional considerations rather devices. electric power grid that than security, they may be To remain competitive in the global incorporates cutting-edge vulnerable to attack. In power market, U.S. industry needs technologies to achieve conjunction with utilities and standards that are internationally unprecedented efficiency, vendors, NIST researchers are acceptable. International comparisons reliability, and safety. identifying these weaknesses and are essential for the validation of reviewing the standards affected measurement techniques used at by them. National Metrology Institutes across Deregulation has also opened the the globe and also for transnational door to suppliers using non- sales of electric power.

68 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed hardware and software to test more secure electric power communication techniques and to make sure that these techniques meet the relevant standards. • Orchestrated, led, and analyzed a comparison of electric power measurements among countries that participate in the Interamerican Metrology System (SIM; North, South, and Central America). • Performed essential electric power metrology for the Smart Grid, a model for the modernization of electric power production and distribution. The Smart Grid will be more reliable, efficient, and safer than today's grid.

Selected Publications

• B. C. Waltrip, B. Gong, T. L. Nelson, C. J. Burroughs, A. Rüfenacht, S. P. Benz, P. D. Dresselhaus, Y. Wang, “Ac power Standard Using a Programmable Josephson Voltage Standard,” IEEE Transactions on Instrumentation and Measurement (2009, accepted)

Figure 1. Calibrating a Measurement Unit (PMU).

Contact

Thomas Nelson

(301) 975-2986

[email protected]

Electronics and Electrical Engineering Laboratory 69 QUANTUM SENSORS

Summary Description

The ability to accurately The Quantum Sensors Project is a uranium and plutonium isotopic measure the energy of world leader in developing new mixtures. The gamma-ray devices photons from the infrared to detector systems. Project are being developed specifically to gamma rays enables amazing researchers have developed tran- help in the verification of inter - scientific applications, from sition edge sensors (TES) for use in national nonproliferation treaties, probing the origins of the a variety of applications. These by determining the plutonium universe to detecting terrorist devices utilize a strip of super- content of spent nuclear fuel. The activities. The Quantum conducting material, biased in its alpha-particle devices have simi - Sensors Project develops transition from normal to super- larly impressive performance and sensors based on quantum conducting states, as an extremely have demonstrated the ability to phenomena for spectroscopy, sensitive thermometer. This ther- analyze mixed-actinide samples. imaging, and other precision mometer is attached to an absorber These detectors are being deve- measurements. EEEL that is isolated from a cold ( 100 loped for use in nuclear forensics. integrates these sensors with mK) by a micromachined of both systems have custom superconducting and structure. The heat deposited by been delivered to our collaborators room-temperature incident photons is then measured at Los Alamos National Laboratory. electronics, cryogenic to accurately deter mine their In the infrared regime, our TES structures, and software to energy. These TES detec tors and bolometers have achieved world- create complete measurement superconducting quan tum inter - record sensitivity. This impressive systems. Working with ference device (SQUID) readout result confirms the utility of TES collaborators in industry, circuits are desig ned, fabricated, technology for this application as academia, and other and implemented for use by a well. We are actively collaborating government agencies, EEEL variety of different scientific and with many groups and are applies this measurement technical communities. providing either detectors or capability to applications One example is the development of superconducting readout and including materials analysis, gamma-ray and alpha-particle multiplexing circuits to many particle physics, nuclear detectors based on TES technology infrared and sub-millimeter nonproliferation and that have more than 10 times instruments. Most recently, our forensics, , better energy resolution than detector efforts are focused on cosmology, and homeland conventional detectors. These developing new - defense. detectors can resolve more lines in sensitive bolometers for cosmic the complicated gamma-ray spectra microwave background measure- of nuclear materials such as ments.

70 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Delivered gamma-ray and alpha-particle spectrometer systems to Los Alamos National Laboratory for development of nuclear forensic methods. • Achieved world-record alpha-particle spectral resolution using TES detectors. • Delivered detector and components to several astronomical instruments including the Atacama Cosmological , SCUBA-2, SPIDER, and the South Pole Telescope. • Designed, fabricated, and tested polarization-sensitive pixels suitable for cosmic microwave background measurements. • Demonstrated (with Konrad Lehnert, Physics Laboratory) parametric with sub-quantum noise-squeezed behavior.

Selected Publications

• R. D. Horansky, J. N. Ullom, J. A. Beall, G. C. Hilton, K. D. Irwin, D. E. Dry, E. P. Hastings, S. P. Lamont, C. R. Rudy, M. W. Rabin, “Superconducting Calorimetric Alpha Particle Sensors for Nuclear Nonproliferation Applications,” Appl. Phys. Lett. 93, 123504, DOI:10.1063/1.2978204 (2008) • J. A. B. Mates, G. C. Hilton, K. D. Irwin, L. R. Vale, K. W. Lehnert, “Demonstration of a Multiplexer of Dissipationless Superconducting Quantum Interference Devices,” Appl. Phys. Lett. 92, 023514, DOI:10.1063/1.2803852 (2008) • N. A. Miller, G. C. O'Neil, J. A. Beall, G. C. Hilton, K. D. Irwin, D. R. Schmidt, L. R. Vale, J. N. Ullom, “High resolution X-ray Transition-Edge Sensor Cooled By Junction ,” Appl. Phys. Lett. 92, 163501, DOI:10.1063/1.2913160 (2008)

Figure 1. SQUID-based multiplexer for SCUBA-2: This 1280 pixel (32 column x 40 row) multiplexer is used as the readout circuit for a submillimeter-wavelength astronomical camera for the SCUBA2 instrument currently operating on Mauna Kea in Hawaii. Figure 4. Focal plane of 256 pixel gamma spectroscopy system. In this picture, three of the four detector bays are populated with gamma-ray detector chips. The chip on the far right is a fully functional 64 pixel detector, while the other populated bays contain test chips.

Contact

Figure 3. Focal plane for BICEP-2, a 256-pixel Kent Irwin Figure 2. One pixel of a SQUID multiplexer polarimeter array being developed at readout circuit currently being used by a JPL/Caltech with NIST SQUID for (303) 497-4991 variety of astronomical instruments deployment at the South Pole. Photos including the Atacama Cosmological courtesy A. Turner (JPL) and J. Brevik [email protected] Telescope in Chile. (Caltech).

Electronics and Electrical Engineering Laboratory 71 QUANTUM INFORMATION AND MEASUREMENTS

Summary Description

America’s future NIST is home to a broad interdisciplinary (“entanglement”) of multiple quantum prosperity and security program in quantum information entities, probing at a fundamental level may rely in part on the science, which is exploring multiple the limits which quantum phenomena exotic properties of of qubits. The efforts place on electrical measurements, and quantum . include ion-trap quantum computing led creating instrumentation to approach Research on quantum by national Medal of Science Winner these limits. information (QI) seeks to Dave Wineland, neutral atom quantum In concrete terms, this work includes control and exploit these computing led by Nobel laureate Bill theoretical investigations of properties, and researchers , and quantum computing interactions in qubits and single-charge are already generating incorporating superconducting qubits devices as well as design, fabrication, “unbreakable” codes for led by Ray Simmonds of this project. and characterization of a wide variety ultra-secure encryption. Each of these approaches has associated of superconducting microdevices. In They may someday build advantages and challenges. Qubits made the qubit arena, we have significantly quantum computers that from ions and atoms are relatively easy improved performance by modifying can solve problems in to isolate from environmental influences the device structure to reduce or seconds that today’s best and thus can maintain their coherence or remove dielectric materials (which could not stable quantum state for longer times. contain naturally occurring or “rogue” solve in years. This project They are, however, more difficult to qubits originating in atomic-level applies the properties of a manipulate, and their properties are defects) from the circuits where macroscopic quantum dictated by nature. Superconductivity possible and to substitute more defect- system, superconductivity, can be used to create “artificial atoms” free materials where they cannot be to the development of which are easy to connect to each other removed. (Complementary work on quantum bits (qubits), and manipulate but are more susceptible quantum materials for qubits is being quantum circuits, and to decoherence by interaction with their performed in the Quantum Magnetic electrical measurement environment. Work in this project falls Sensors and Materials Project.) In the techniques that are limited into several areas: improving the instrumentation area, we have only by the laws of performance of superconducting qubits designed and demonstrated ultra-low- quantum physics. by understanding the sources of noise superconducting microwave decoherence and mitigating them, amplifiers which have the promise to creating and demonstrating the improve microwave measurements in a elements of a quantum computer such broad array of applications and as quantum memory and a quantum potentially push these measurements to bus, investigating the interaction the quantum limit.

72 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Demonstrated coherent quantum state storage and transfer between two phase qubits. Featured on the cover of Nature. • Demonstrated DC SQUID microwave amplifier operating in the 7 GHz band with world record gain. • Developed vacuum gap capacitors and crossovers and integrated them into superconducting qubits. • Developed a resonator technique for evaluating qubit materials which allows rapid screen of candidate materials and fabrication methods. • Performed seminal work on the role of quasiparticle poisoning in superconducting circuits which has had a major effect in redirection of qubit development.

Selected Publications

• M. A. Sillanpaa, J. I. Park, R. W. Simmonds, “Coherent Quantum State Storage and Transfer Between Two Phase Qubits Via a Resonant Cavity,” Nature, Vol. 449, No. 7161, pp. 438-442 (2007) • L. Spietz, K. Irwin, J. Aumentado, “Input Impedance and Gain of a Gigahertz Amplifier Using a DC Superconducting Quantum Interference Device in a Quarter Wave Resonator, “ Applied Physics Letters, Vol. 93, No. 8, pp. 082506-1-3 (2008) • O. Naaman and J. Aumentado, “Poisson Transition Rates from Time-Domain Measurements with a Finite Bandwidth,” J., Physical Review Letters, Vol. 96, No. 10, pp. 100201/1-4 (2006)

Figure 1. Depiction of a single microwave photon being transmitted between two superconducting qubit circuits, creating for the first time a “quantum electrical bus” between qubits that preserves and transfers the quantum state from one qubit to the other. Figure 2. Micrograph of a superconduc- ting qubit circuit that incorporates a unique vacuum gap capacitor to reduce dielectric decoherence in the circuit.

Contact

Bob Schwall

(303) 497-4732

[email protected]

Electronics and Electrical Engineering Laboratory 73 QUANTUM MAGNETIC SENSORS AND MATERIALS

Summary Description

Ultra-sensitive magnetic NIST is a world leader in the making a tunnel barrier. sensors, quantum computers, area of high-sensitivity Traditionally these tunnel and next-generation magnetic field sensors. To junctions use convenient semiconductors all require the achieve this, EEEL has explored amorphous, thermal oxide fabrication of extremely pure spintronic devices, including barriers because the thickness is well-characterized materials. anisotropic magneto-resistive easily controllable, and they tend Quantum coherent materials (AMR) and tunneling magneto- to be pin-hole free. However, it show great promise for resistive (TMR) devices. With has been shown that these layers magnetic sensors as well as the AMR devices, researchers have energy-absorbing defects information processing developed tape read heads with at random frequencies due to technology. For magnetic many sensing elements. These their amorphous nature. sensors, spin-based transport in devices are designed to operate Therefore, EEEL developed a metals and across tunnel at DC and are used to image process to grow epitaxial tunnel barriers is important because it magnetic tapes. A system was junctions. This was challenging increases the signal to noise and built for the FBI that is being because the tunnel current reduces the power. These validated for use on analog depended exponentially on the devices have applications in a audio tape evidence. The TMR barrier thickness, and epitaxial wide variety of fields, ranging devices are targeted towards barriers require high from sensing to imaging. EEEL low-noise field sensors and are temperatures to crystallize. has developed large element integrated with a flux Working around these issues arrays and systems to make concentrator. EEEL researchers using precision, ultra-high forensic copies of magnetic have achieved noise levels vacuum molecular beam epitaxy tapes for data migration and better than one millionth of the (MBE) growth, and lattice authenticity analysis. In the area Earth’s magnetic field, with a matched, superconducting of quantum computing, EEEL is sufficient dynamic range to run rhenium films on sapphire developing crystalline tunnel them in an unshielded substrates, EEEL is the first to be junctions that will improve environment. These devices are able to fabricate, characterize, quantum state visibility and very low power and are and successfully integrate them measurements. EEEL is also targeted toward geological and into devices. In addition, the working to improve the exploratory work. performance of the devices coherence of these devices by For quantum computing, EEEL is improved significantly, enabling developing low-loss dielectrics. developing superconducting us to use optical lithography devices using a novel approach to rather than e-beam.

74 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Developed low-noise magnetic field sensors applicable for geological applications. • Developed magnetic imaging arrays and a system for conducting forensic analysis of magnetic tapes using this technology. • Demonstrated the first implementation of epitaxial Josephson junction for quantum computing applications. • Demonstrated that epitaxial Josephson junctions reduce the number of detrimental splittings in a solid state qubit.

Selected Publications

• F. C. S. da Silva, S. T. Halloran, A. B. Kos, D. P. Pappas, “256-Channel Magnetic Imaging System,” Rev. Sci. Instrum. 79, 013709 (2008) • S. Oh, K. Cicak, J. S. Kline, M. A. Sillanpää, K. D. Osborn, J. D. Whittaker, R. W. Simmonds, D. P. Pappas, “Elimination of Two Level Fluctuators in Superconducting Quantum Bits by an Epitaxial Tunnel Barrier,” Phys Rev. B74 Rapid Communications, 100502® (2006) • F. C. da Silva, S. T. Halloran, L. Yuan, D. P. Pappas, “A Z-Component Magnetoresistive Sensor,” Applied Physics Letters 92, 142502 (2008)

Figure 1. One second of audio in a imaged using the 256-sensor array showing: (I) regular audio signature, (II) erased region, and (III) erase head stop Figure 2. Qubit spectroscopy showing the event. The white arrow between regions I and II indicates the erase mark starting of the qubit being in the <1>| state point. The dotted rectangle highlights the erase stop event showed in detail in (b) and after a long microwave pulse is applied at each compared with the Bitter imaging technique (c). The black arrows indicate the bias current; the brighter the color, the higher the recorder signature marks. probability. When the microwave energy is equal to the energy spacing between the lowest two levels of the qubit, this probability reaches a maximum. (a) An amorphous barrier qubit and (b) an epitaxial barrier qubit. Both qubits have identical junction areas. The only difference is the trilayer structure.

Contact

David Pappas

(303) 497-3374

[email protected]

Electronics and Electrical Engineering Laboratory 75 76 Electronics and Electrical Engineering Laboratory ELECTROMAGNETICS DIVISION

The Electromagnetics Division develops and promotes electromagnetic measurements, standards, and technology to support a broad range of technical needs. The Division’s programs focus on accurate and reliable measurements throughout the radio spectrum. Key program directions include: (1) development of advanced measurement technologies required by both research-and-development and manufacturing communities; (2) the development and characterization of standard reference artifacts, measurement methods, and services that provide the basis for international recognition of measurements; and (3) the provision of expert technical support for national and international standards activities. Examples to indicate the breadth of areas influenced by our programs include high-speed microelectronics for computation and telecommunications, advanced antenna systems for applications in military and deep space communications, remote observation of the Earth’s biosphere, acquisition and quantitative characterization of high-speed waveforms, medical diagnostic imaging, and reliable communications for our nation’s emergency first-responders.

The Division’s technical activities are organized into three research groups. The Radio- Frequency Electronics Group provides a broad range of state-of-the-art calibration services for fundamental radio-frequency and microwave quantities, which ensures that the U.S. scientific and industrial base has access to a measurement system that is reliable, accurate, and internationally accepted. In addition, this group extends new measurement tools and to higher operating frequencies, wider signal bandwidth, and smaller length scales. These are required for next-generation applications in microelectronics, high-speed communications, computing, and data storage. This group also develops new methods to measure the electromagnetic properties of materials and understand the interactions of electromagnetic waves with advanced materials.

The Radio-Frequency Fields Group develops theory and measurement techniques for the characterization of fundamental properties of advanced antenna systems and for the accurate measurement of electromagnetic fields. These capabilities are applied to the measurement of emissions and susceptibilities of electronic systems and devices. Of growing interest is the development of advanced measurement methods to characterize complex modulated telecommunication signals and to study the challenges faced by advanced communications when operated in complex real-world environments.

The Magnetics Group performs advanced research on fundamental aspects of and magnetodynamics, with particular focus on the behavior of nanoscale devices and systems for applications to magnetic sensors, magnetic information storage, and spintronics. This group also develops measurement technologies, methods and systems for quantitative biomagnetic imaging and “smart” magnetic contrast agents. In addition, this program maintains unique capabilities for the electromechanical characterization of superconductors, which enables large-scale applications of superconducting technologies.

Electronics and Electrical Engineering Laboratory 77 ADVANCED HIGH-FREQUENCY DEVICES

Summary Description

Ceaseless demand for increases in speed The primary goal of this program is hand they recognize that and integration of electronic devices metrology that enables advanced quantitative measure ment will drives a large segment of U.S. economic high-frequency device make a major contribution to activity and impacts virtually every (electronics) development. Based these efforts. On the other hand, aspect of modern life, from improved on current trends in high- these industrial entities are not medical diagnostics to faster computers frequency electronics, the program able to clearly articulate their to higher bandwidth communications. is focused on metrology for two measurement needs. In addition The operating frequencies of electronics classes of devices: (1) high- to clarifying and providing the are rapidly moving into the microwave frequency nanoscale devices measurement methods, work in frequency range and beyond, while (bringing high-frequency to the this field will enable new integration requirements force device nanoscale) and (2) high-frequency functionality that goes beyond sizes down to the nanometer scale. This devices based on novel materials conventional electronics. The trend requires ever faster, more (bringing high-frequency to new initial investment in this area has sensitive, and less invasive characteri - materials). yielded several specific zation techniques and creates entirely By learning how to fabricate and achievements: broadband new measurement challenges related to measure specific devices, this characterization of nanotubes, strong interactions among devices and program develops metrology that advances in near-field microwave with the local environment. Further is broadly applicable to whole microscopy, and superconducting progress in the incorporation of novel classes of devices. The microwave power limiters. nanotechnologies into electronics and electronics research-and- External agencies, including the communications applications is contin- development community of Defense Advanced Research gent on the develop ment of high- industry, government, and Projects Agency (DARPA) and the frequency metrology at the nanoscale to academia needs the metrological Office of Naval Research (ONR), define the relevant technical barriers and tools that are being developed to have recognized the value of this develop strategies to overcome them. discern which high-frequency program and have invested The Advanced High-Frequency Devices device they should accordingly. Over the course of Program develops measurement pursue and which they should the next 5 to 10 years, we will techniques and devices for characte - abandon. The impact of these build on established rizing nanoscale structures relevant for developments on the electronics measurement techniques to apply beyond CMOS electronics, high- industry will be immense. Several high frequency electromagnetic frequency bioelectronic applications, and industrial consortia have been metrology to nanoscale devices localized electromagnetic-field imaging. created just to pursue research for electronic and biological on advanced devices. On the one systems.

78 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Designed, fabricated, measured, modeled, and performed error analysis for two-, high-frequency, GaN nanowire devices. • Developed a full model for characterization of nanoscale two-port devices. The model includes device characteristics as well as contact impedance.

• Performed broadband measurements of SrTiO3 thin films at room temperature. These are the basis for a chapter on challenges in thin-film measurements. • Developed integrated microelectronic-microfluidics measurement structures for broadband electromagnetic characterization of picoliter fluid volumes.

Selected Publications

• T. Wallis, A. Imtiaz, H. Nembach, P. Rice, P. Kabos, “Metrology for High-Frequency Nanoelectronics,” 2007 International Conference on Frontiers of Characterization and Metrology for Nanoelectronics (formerly, Characterization and Metrology for ULSI Technology), Gaithersburg, MD (2007) • N. Orloff, J. Mateu, M. Murakami, I. Takeuchi, J. C. Booth, “Broadband Characterization of Multilayer Dielectric Thin-Films,” 2007 IEEE MTT-S International Microwave Symposium, Honolulu, HI (2007) • J. C. Booth, N. Orloff, J. Mateu, “Nonlinear Effects in Thin-Film Ferroelectric Transmission Lines at Microwave Frequencies,” Proc. International Symposium on Applications of Ferroelectrics, Santa Fe, NM (2008)

Figure 1. On-wafer nonlinear characterizations.

Contacts

Jim Booth Phone: (303) 497-7900 [email protected]

Pavel Kabos, Phone: (303) 497-3997 [email protected]

Electronics and Electrical Engineering Laboratory 79 ADVANCED MATERIALS METROLOGY

Summary Description

Everywhere around us are materials Over 100 years ago it dawned on EEEL is performing state-of-the- that are composed of tiny molecules scientists that a moving charge art research that anticipates the and atoms that are influenced by produced electromagnetic waves measurement needs of industry invisible electromagnetic rays that that traveled at the speed of light. years in advance in travel as radio waves, microwaves, Later it was found that these nondestructive substrate and sunlight. Just how these waves waves traveled as corpuscles measurements, micro fluidics, behave near and in materials has a called photons that interacted low- thin-film characterization, strong influence on many areas of with materials. Electromagnetic and near-field probing tech- our life, from the TV we watch to devices cannot operate without niques. Industry, universities, devices in the doctor’s office. the interaction of electromagnetic other government laboratories, Understanding and harnessing the waves with materials, and the and standards committees have interaction of microwaves with characterization of the interface adopted many EEEL measurement materials and the electrical between fields and materials will methods. These include systems properties of materials is very be a critical task for any device or and test fixtures, best practices, important to the development of metrology development from and documentary standards. new medical technologies and new nanoscale to larger scales. EEEL EEEL is expanding capabilities in electronics. The primary objectives of areas of impact over the next 5 to advanced areas of near-field the Advanced Materials Metrology 10 years will be developing microwave microscopy, liquid Program are to develop, improve, measurements at frequencies characterization, and micro- and analyze measurements of the approaching 1 terahertz, defining fluidics. electromagnetic properties of theoretical concepts, and The benefits of this work are materials from the large-scale down developing the optimum many. Quantifying the interac- to the nanoscale. The emphasis for measurement tools to extend tion of electromagnetic fields the program is on measurement electromagnetic metrology and with matter is a fundamental methods for substrates, thin films, reference materials to the measurement challenge. This liquids, biological materials, and nanoscale. We will develop quan- work directly benefits and artificial materials. Our program will titative electromagnetic measure - leads basic research and devel- advance the state of the art by ments of thin-film electronic opment in microelectronics, introducing advanced concepts materials, liquids, biomaterials, , and nanotech- based on the underlying physics that and other advanced materials over nology and influences a wide govern the nature and properties of a wide range of experimental range of commercial, military, the materials. conditions including frequency, and homeland security appli- temperature, and magnetic fields. cations.

80 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Constructed and evaluated a liquid test fixture for the Transportation Security Administration (TSA). • Completed a study of the interaction of radio-frequency to terahertz electromagnetic fields with material sizess from the macroscopic to nanoscale. • Completed an electromagnetic analysis of near-field nanoscale probes. • Completed an analysis of split-post and split-cylinder resonance techniques. • Performed on-wafer metrology to study printed wiring board measurement problems.

Selected Publications

• J. Baker-Jarvis, M. D. Janezic, J. H. Lehman, “Dielectric-Resonator Method for Measuring the Electrical Conductivity of Carbon Nanotubes from Microwave to Millimeter Frequencies,” Journal of Nanomaterials, vol. 2007, 12086 (2007) • J. Baker-Jarvis, M. D. Janezic, D. Love, T. M. Wallis, C. L. Holloway, P. Kabos, “Phase Velocity in Resonant Structures,” IEEE Transactions on Magnetics, vol. 42, pp. 3344- 3346 (2006) • M. Janezic, J. Jargon, J. R. Baker-Jarvis, “Relative Permittivity Measurements Using the Higher-Order Resonant Mode of a Near-Field Microwave Probe,” International Union of Radio Science (URSI), Chicago, IL (2008)

Figure 1. Dielectric measurement of liquids.

Contact

James Baker-Jarvis

(303) 497-5621

[email protected]

Electronics and Electrical Engineering Laboratory 81 FUNDAMENTAL GUIDED-WAVE METROLOGY

Summary Description

Information zips around inside modern The number of devices that use to support their internal calibration personal computers at microwave microwaves is constantly growing. processes. This includes frequencies. At these speeds, the There is a constant push to use higher establishing their traceability, information can interact with the frequencies. Signals are becoming support for accreditation, materials of the computer chips and much more complex, including calibration standards, and buses and possibly change in modulation effects, multiport/ verification of their systems. The unexpected ways. These interactions differential signals, complex systems supported by these must be measured and understood to waveforms, and other unusual signal measurements may be anything keep computers functioning correctly, schemes. The capability to measure from satellite systems to weapons especially as they get smaller and faster. signals on integrated circuits is or other military systems, Helping computer chip manufacturers becoming critical for advanced computer chips, cell phones, or make these measurements is just one devices. These new requirements are microwave ovens. One recent example of how the microwave dictated by the needs of the example is a calibration for the standards and measuring techniques telecommunication, computing, Food and Drug Administration developed by the Fundamental Guided- defense, and general electronics (FDA) to support its microwave Wave Metrology (FGWM) Program of communities. EEEL’s work looks at oven standards. The microwave EEEL supports industry. A common set the fundamental measurement measure ment services are being of basic measurement capabilities and problems for microwave thermal transformed to better meet the standards are necessary to support all noise, scattering-parameter, power, needs of the program’s customers. these different users of RF and and waveform measurements. A The FGWM Program is developing a microwave devices. The FGWM Program large range of state-of-the-art strategy for moving the develops and maintains the U.S. national microwave measurement measurement services into the standards for RF and microwave capabilities, theoretical future and is developing improved quantities, providing a wide range of developments, techniques, and methods for delivering the state-of-the-art measurement standards for customers are services. The main cornerstone of capabilities and develops new provided. The FGWM Program covers this approach is a strong research- measurement methods and systems. from 100 kilohertz to above 110 and-development program in these Everyday consumer devices (such as gigahertz. areas. The measurement services microwave ovens) as well as future The customers for the microwave are a natural outcome of the advanced electronics systems are measurement services come from a program’s focus on the research of supported by the work of the FGWM broad slice of the electronics the fundamental metrology that Program. industry. These customers underlies the measurement generally use NIST measurements capabilities.

82 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Completed and evaluated a new WR-15 calorimeter for power measurements. • Completed a 1.85 millimeter direct comparison power system and uncertainty analysis. • Extended s-parameter capabilities to 1.85 millimeter connectors with uncertainty analysis. • Constructed and tested a 400 gigahertz electro-optic sampling system. • Terminated the classic artifact-based s-parameter measurement services. (These are being replaced with a measurement comparison approach.)

Selected Publications

• A. Lewandowski, D. Williams, “Characterization and Modeling of Random Vector Network Analyzer Measurement Errors,” 17th International Conference on Microwaves, Radar and Wireless Communications (MIKON) (Warsaw, Poland), pp. 1-4 (2008) • J. P. Randa, D. K. Walker, “On-Wafer Measurement of Transistor Noise Parameters at NIST,” IEEE Transactions on Instrumentation and Measurement, vol. 56, pp. 551- 554 (2007) • D. Gu, D. Walker, J. P. Randa, “Noise-Parameter Measurement with Automated Variable Terminations,” Conference on Precision Electromagnetic Measurements (CPEM), Broomfield, CO (2008)

Figure 1. Probe station for making automated on-wafer device measurements.

Contact

Ronald Ginley

(303) 497-5737

[email protected]

Electronics and Electrical Engineering Laboratory 83 ANTENNA METROLOGY

Summary Description

Antennas are the eyes, ears, EEEL’s Antenna Metrology Program has of kilometers — and continue to and voices of everything for three decades served companies advance it both theoretically and from cell phones to and government agencies seeking to experimentally. The private sector and interplanetary . maximize the efficiency of other government agencies provide The Antenna Metrology communications, relying on the world’s most testing services based on EEEL’s Program carries on EEEL's highest performance antennas. -breaking work. In hundreds of pioneering work on testing Program physicists and engi neers are test ranges worldwide, engineers test high-end antennas for leaders in testing key antenna antennas using probes designed to critical hardware such as performance characteristics used in capture an antenna’s output. In the communications satellites, some of the world’s most sensitive U.S., each antenna probe is NIST- scientific spacecraft, radar, applications, such as those of radar and traceable, or NIST-calibrated. Such and aircraft. The program aircraft and of satellites and spacecraft testing measures an antenna’s near- focuses on improving its vital for communications, weather field at close distances (a few near-field scanning method, , and space science. Precise centimeters), then uses mathematical which transforms understanding of antenna perfor- algorithms developed at NIST to measurements taken at mance enables of determine the far-field. Near-field centimeter distances into satellites and spacecraft bound for scanning allows for accurate accurate predictions of an other planets to avoid overbuilding assessment of the gain (the amount of antenna’s far-field, valid at antennas and related power sources, power transmitted or received in the distances of kilometers and such as batteries and solar panels. They antenna’s primary direction), beyond. Using mathematical can thereby minimize spacecraft polarization (the orientation of the tools developed at EEEL, the — and costs — where an ), and pattern technique is used at incremental pound can cost $10,000 to (the angular distribution of transmitted hundreds of test ranges launch. Equally important, proper or received energy) of antennas worldwide. Recent advances testing of antennas on scientific operating at frequencies from 1.5 promise to extend the spacecraft costing hundreds of millions gigahertz to 110 gigahertz. method’s use. of dollars provides assurance that Project scientists recently scored a precious data will make it back to Earth. major success in the race to stay ahead EEEL scientists pioneered the near-field of increasing antenna frequencies with scanning technique — now the standard their development of a dynamic laser- method for testing high-performance based antenna-probe tracking system antennas designed to communicate with probe-position correction across tens, thousands, or even millions algorithms, which enable the use of

84 Electronics and Electrical Engineering Laboratory existing near-field scanning ranges at radiometer systems for improved much higher frequencies than weather and climate prediction. Project previously attainable — thereby scientists are also working on imaging extending the life of some of the applications that could one day nation’s key antenna-testing infra- pinpoint undesired electromagnetic structure. Such higher frequencies hold reflections in test chambers, enabling significant promise in the areas of even more accurate antenna medical and security imaging and calibration.

Major Accomplishments

• Completed and documented a method for estimating uncertainty due to the source of known brightness temperature being in the near-field of the radiometer. • Determined gains and compared results of three antennas (one dual-port probe) using both the extrapolation and pattern integration methods. • Established a test bed at 13.56 megahertz for testing radio-frequency identification (RFID) cards for load modulation (return signal strength) and durability when cards are exposed to or to high strength alternating electric and magnetic fields.

Selected Publications

• M. Francis, R. Wittmann, “Near-Field Scanning Measurements: Theory and Practice,” in Modern Antenna Handbook, John , Ch. 19, pp. 929-976 (2008) • R. Wittmann, M. Francis, R. Direen, “Chamber Imaging Using Near-Field Scanning,” in Proc. 2008 IEEE Antennas and Propagation Symposium (San Diego, CA), ID 10.1109/APS.2008.4619141 (2008) • J. Guerrieri, K. MacReynolds, M. Francis, R. Wittmann, D. Tamura, “Planar Near-Field Measurement Results Up To 94 GHz Using Probe Position Correction,” in Proc. 27th AMTA Symposium (Newport, RI), pp. 110-116 (2005)

Figure 1. The EEEL millimeter-wave extrapolation range being prepared for antenna measurements.

Contact

Michael Francis

(303) 497-5873

[email protected]

Electronics and Electrical Engineering Laboratory 85 FIELD PARAMETER METROLOGY

Summary Description

Consider the consequences if This program generates reference EM evaluated for EMC up nearby electronics could fields and calibrates EM probes to 40 gigahertz. Closed test systems interfere with a jet’s required for their accurate such as transverse EM cells have been instruments or cause an measurement. Accurate EM field widely adopted for testing small automobile to stall. measurements are needed to charac- antennas, sensors, and probes, but are The Electromagnetic Field terize our wireless world and ensure normally limited by geometrical Parameter Program develops that the valuable electromagnetic constraints to below 1 gigahertz. EEEL ways of measuring spectrum is optimally used, that recently finished and electromagnetic (EM) electronic systems are compatible and testing of a new closed-cell co-conical emissions and susceptibilities neither sources nor victims of EM system that can be used to to electronic interference interference, and that people are not test such devices up to 45 gigahertz. of electronic devices exposed to hazardous fields. As instru - This new test fixture reduces test times and systems. mentation and electronics achieve from weeks to hours. The program maintains the higher clock rates, EM field parameter The program provides information to capability to provide EM field metrology is needed at ever higher standards organizations to help measurements. frequencies. The program is working to correlate measurements between Applications include the extend current methods and facilities to various EMC test facilities. The program communications needs of higher frequencies and develop new also coope rates with the national test first-responders to test methods to increase accuracy and laboratories of our international emergencies, measurements reduce measurement costs. partners to perform round-robin of the shielding effectiveness The program is working on extending testing and comparison of standard of advanced materials, open area test site test methods to antennas and probes. This assures effects from and on other frequencies above the 1 gigahertz international agreement in their electronic components, specified by most international performance and reduces the uncer- the of electromagnetic compatibility (EMC) tainties in the areas of metrology that electromagnetic fields in standards. Fully anechoic chambers are affect international trade. The rooms and buildings, accepted as standard sites for program’s goal is to develop and and the effects on biological approximate free-space measure - evaluate reliable and cost-effective subjects. ments. Time domain methods are being standards, test methods, and measure- studied as a way to measure the ment services related to complex EM characteristics of these rooms and to fields for EMC of electronic devices and improve the results obtained therein. other applications in health, defense, This type of chamber is also being and homeland security.

86 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Completed a co-conical field generation system (CFGS) for the Air Force. The CFGS will reduce hazard probe calibration times from weeks to hours. • Completed and documented high-intensity radiated field (HIRF) shielding effectiveness tests on representative commercial aircraft (Boeing 737-200, Boeing 767-400ER, Bombardier Global 5000, Beechcraft Premier 1A Composite Business Jet); the results were delivered to the FAA. • Described analytically and verified experimentally a new method to quantify the shielding effectiveness of physically small but electrically large enclosures (e.g., instrument and computer housings) in reverberation chambers; introduced the method into the applicable IEEE standard.

Selected Publications

• K. Remley, G. Koepke, C. Holloway, C. Grosvenor, D. Camell, J. Ladbury, D. Novotny, W. Young, G. Hough, M. McKinley, Y. Becquet, J. Korsnes, “Measurements to Support Broadband Modulated-Signal Radio Transmissions for the Public-Safety Sector,” NIST Technical Note 1546 (2008) • C. Grosvenor, D. Camell, G. Koepke, D. Novotny, R. Johnk, “Electromagnetic Airframe Penetration Measurements of a Beechcraft Premier 1A,” NIST Technical Note 1548 (2008) • D. Camell, R. Johnk, D. Novotny, C. Grosvenor, “Free-Space Antenna Factors Through the Use of Time-Domain ,” in Proc. 2007 IEEE International Symposium on Electromagnetic Compatibility (Honolulu, HI), pp. 1-5 (2007)

Figure 1. The co-conical field generation system developed by EEEL in preparation for testing.

Contact

Galen Koepke

(303) 497-5766

[email protected]

Electronics and Electrical Engineering Laboratory 87 WIRELESS SYSTEMS METROLOGY

Summary Description

Imagine how much safer a fire The Wireless Systems Metrology based representations and the fighter’s job would be if it Program supports the growing effects of terminating impedance were possible for a to wireless industry by developing on intermodulation . navigate in a burning building methods to test the operation and Researchers are also working to and locate those in need of functionality of wireless devices in develop traceability to fundamental assistance. the presence of various types of parameters such as power and The Wireless Systems distortion. This includes multipath electric field. Metrology Program develops distortion, ranging from a line-of- ways to measure complex sight environment (low-multipath) telecommunication signals to a pure Rayleigh environment used by industry, public (high-multipath). safety (rescue workers), The Wireless Systems Metrology and government. Program is also concerned with the The program develops impact of nonlinear distortion on methods to measure the transmission of wireless signals, communication and data which can be especially severe for signals and to imitate complex new wideband modulated signal environments where reliable transmissions. Accurately reception may be a problem. measuring distortion behavior of Applications include nonlinear radio-frequency devices developing tests to evaluate is a key element in understanding the effects of interference on how the device will perform once it wireless communications used is incorporated into a system. Even in factories for the control of under weakly nonlinear conditions, robots, methods to measure low-noise devices such as those cellular telephone fields, used in receiver front ends will test facilities for evaluating exhibit nonlinear behavior that search and rescue includes harmonic generation and communications, and intermodulation distortion. The robot communications. program has studied problems that commonly arise in performing and interpreting nonlinear measure- ments, such as power- and wave-

88 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Demonstrated that a reverberation chamber can be used to generate a variable multipath environment, which allows wireless devices to be tested in the laboratory rather than in field tests. • Developed standards to ensure reliable wireless communications for emergency responders in difficult radio environments. • Assisted the National Institute of Environmental Health Sciences, which is conducting a long-term animal study to evaluate health risks associated with cellular telephone fields, by testing the performance of 21 reverberation chambers that will be utilized in the study.

Selected Publications

• E. Genender, C. Holloway, K. Remley, J. Ladbury, G. Koepke, H. Garbe, “Using a Reverberation Chamber to Simulate the Power Delay Profile of a Wireless Environment,” in Proc. 2008 EMC Europe Symposium (Hamburg, Germany), pp. 219- 224 (2008) • K. Remley, G. Koepke, C. Grosvenor, R. Johnk, J. Ladbury, D. Camell, J. Coder, “NIST Tests of the Wireless Environment in Automobile Manufacturing Facilities,” NIST Technical Note 1550 (2008) • K. Remley, G. Hough, G. Koepke, R. Johnk, D. Camell, C. Grosvenor, “Wireless Communications in for Urban Search and Rescue Robots,” in Proc. 2008 Performance Metrics for Intelligent Systems, Gaithersburg, MD (2008)

Figure 1. EEEL staff measure the wireless communication link environment in an automotive factory.

Contact

Catherine Remley

(303) 497-3652

[email protected]

Electronics and Electrical Engineering Laboratory 89 NANOMAGNETICS

Summary Description

Hard-disk drives in personal Future computer hard disk drives are responsible for nano-oscillator computers continue to likely to require patterned media and solved a potential become smaller, faster, and composed of uniform, barrier to widespread application cheaper. These magnetic perpendicularly magnetized nanodots by demonstrating how oscillations devices push the limits of instead of present-day continuous can be made to occur in a zero technology, with current data magnetic films. EEEL has applied magnetic field. bit densities of 50 billion per demonstrated that the magnetic In addition to oscillators, electron square centimeter. fields required to switch the spin torque may be used to switch The magnetic orientation of magnetization of nanodots is critically future nonvolatile magnetic thin films in write heads, read dependent on the quality of their random-access memory (MRAM) heads, and recording media all edges. EEEL is developing new, highly elements. Compared to switching switch extremely quickly. sensitive, magneto-optic instruments memory bits with magnetic fields, The Nanomagnetics Program to measure the dynamics of magnetic this method would offer higher investigates the high- nanodots as a function of frequency, speed, greater reliability, and frequency behavior of with the goal of evaluating nanodot lower power, and it is scalable to nanoscale magnetic materials quality and homogeneity via a rapid smaller device dimensions. EEEL is and devices. The switching of spectroscopic analysis of individual developing methods to measure magnetization at frequencies nanodots. the switching behavior of in the hundreds of megahertz Spintronics exploits the interaction prototype spin-MRAM. to hundreds of gigahertz will between electrons’ spin angular Imperfections in magnetoresistive be the foundation for future momentum and the magnetization sensors give rise to random magnetic data storage of a film. EEEL developed the first magnetic fluctuations, which limit systems and microwave microwave spin-transfer nano- their sensitivity. EEEL has obtained integrated circuits. oscillators based on point current evidence of these These technologies will contacts to planar films. These processes in the form of electron depend on newly discovered oscillators have very sharp microscope images of magnetic properties and limitations of resonant frequencies. EEEL showed domain fluctuations in active magnetic materials and how signals emitted by multiple devices. EEEL has fabricated devices that appear only at nano-oscillators will naturally improved magnetic tunnel-junction the nanoscale. synchronize, coherently combining sensors by annealing them in high their outputs and stabilizing their fields in a reducing environment oscillation frequency. EEEL and by using explained the mechanism concentrators.

90 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Determined that magnetic reversal in perpendicularly magnetized nanostructures is highly dependent on the nature and condition of the edges. • Determined that spin-transfer-driven oscillations in nanocontacts made to spin- valve structures can occur in zero field, which will enable applications such as on- chip timing and signal processing. • Demonstrated mutual phase-locking of microwave spin-torque nano-oscillators. Spin waves, rather than magnetic fields, are the primary interaction mechanism. • Identified sources of 1/f noise and time-dependent nanoscale fluctuations in magnetic films. Imaged magnetic fluctuations in active magnetic sensors.

Selected Publications

• T. J. Silva and W. H. Rippard, “Developments in Nano-Oscillators Based Upon Spin- Transfer Point-Contact Devices,” Journal of Magnetism and Magnetic Materials, vol. 320, pp. 1260-1271 (2008) • W. H. Rippard and M. R. Pufall, “Microwave Generation in Magnetic Multilayers and Nanostructures,” in Handbook of Magnetism and Advanced Magnetic Materials, John Wiley, Sussex, U.K. (2007) • R. Heindl, S. E. Russek, T. J. Silva, W. H. Rippard, J. A. Katine, and M. J. Carey, “Size Dependence of Intrinsic Spin Transfer Switching in Elliptical Spin Valves,” Applied Physics Letters, vol. 92, 262504 (2008)

Figure 1. Top : of a model used to include nanodot edge damage in micromagnetic . Bottom graph: Diameter dependence of the switching field from simulations for various values of edge damage. The insets show the time evolution in a 50 nanometer nanodot as it undergoes reversal in the undamaged and edge- damaged cases over a time of approximately 1 nanosecond. The color scale represents the z-component of the magnetization.

Figure 2. Simulation showing spin-wave Figure 3. Simulation of magnetization for a Figure 4. Removal of a wafer of spin-MRAM interaction between two spin-transfer oscillators. 176 nanometer by 60 nanometer device. Colors devices from ion-beam system. Focused ion beam cut breaks coupling. Oscillators represent the average x-axis magnetization phase-lock without the cut. The scanning (red positive, blue negative). Magnetic electron micrograph shows actual device. oscillations grow until device . Contacts Tom Silva (303) 497-7826, [email protected]

Bill Rippard (303) 497-3882, [email protected]

Stephen Russek (303) 497-5097, [email protected]

Electronics and Electrical Engineering Laboratory 91 BIOMAGNETICS

Summary Description

Magnetic resonance imaging Customized microscopic magnets could Currently, MRI scanners drift over time, (MRI) gives detailed medical add color and sensitivity to MRI. In and different give different images of the body’s internal collaboration with the National images. Quantitative, traceable MRI will tissues and organs without Institutes of Health (NIH), EEEL has provide accurate and consistent images, the use of harmful radiation. shown how such micromagnets could validate disease mechanisms and MRI is based on magnetic as “smart tags” to identify particular therapeutic outcomes, and facilitate the of the protons in cells, tissues, or physiological transition to computer-aided diagnos - water. The Biomagnetics conditions. Each micromagnet consists tics. The will use Program seeks to improve MRI of two round, vertically stacked quantitative MRI to objectively test the through the invention of magnetic disks, a few in efficacy of new drugs. multifunctional magnetic diameter, separated by a gap. Biological and chemical samples contrast agents and the Customized magnetic fields can be naturally emit characteristic signatures development of created by adjusting materials, gap, or of terahertz radiation, but detecting measurements and standards disk thickness or diameter. The open and measuring them is a challenge to make MRI quantitative and design allows the of water because the signals are weak and traceable, instead of through the micromagnet, producing a absorbed rapidly by the atmosphere. A qualitative and instrument signal that may be thousands of times prototype imager developed by EEEL dependent. stronger than that produced by a uses a sensitive superconducting The Biomagnetics Program similarly sized, but stationary, volume detector, microelectronics, and optics also develops terahertz of water. The diffusion effectively to operate in the terahertz range. The detectors with unprecedented increases local MRI sensitivity, which system can detect temperature sensitivity and resolution for could lead to faster imaging, images differences smaller than 0.5 °C, which bio-imaging, identification of that are richer in information, or could differentiate between, for trace chemical molecules, and reduced dose requirements for contrast example, tumors and healthy tissue. remote atmospheric sensing agents. The micromagnets can be made The technique is sensitive enough to to monitor climate change. using conventional detect the weak terahertz signals The imaging of malignant skin techniques and are compatible with naturally emitted by samples, tumors by the passive standard MRI hardware. eliminating the need to actively detection of terahertz In collaboration with a committee of the illuminate them. The technology may radiation is safe International Society for Magnetic become a new tool for early tumor and painless. Resonance in Medicine (ISMRM), EEEL is detection and rapid and precise developing a standard “phantom” for identification of chemical hazards for the calibration of MRI machines. homeland security.

92 Electronics and Electrical Engineering Laboratory Major Accomplishments

• Invented MRI contrast agents with spectral signatures based on the geometry of the magnetic microstructures. • Developed and characterized a passive heterodyne hot electron bolometer imager operating at 850 gigahertz with spatial resolution of 4 millimeters. • Showed that the efficiency of solutions of the single-molecule Fe-8 nanomagnet as an MRI contrast agent compared to that of a gadolinium chelate depends on concentration. • Developed a novel platform for microfluidic manipulation of magnetic particles based on an array of magnetic spin valves with bistable ferromagnetic “on” and antiferromagnetic “off” states.

Selected Publications

• G. Zabow, S. Dodd, J. Moreland, A. Koretsky, “Micro-Engineered Local Field Control for High-Sensitivity Multispectral MRI,” Nature, vol. 453, pp. 1058-1063 (2008) • E. Gerecht, D. Z. Gu, L. X. You, K. S. Yngvesson, "A Passive Heterodyne, Hot Electron Bolometer Imager Operating at 850 GHz," IEEE Transactions on Microwave Theory and Techniques, vol. 56, pp. 1083-1091 (2008) • B. Cage, S. E. Russek, R. Shoemaker, A. J. Barker, C. Stoldt, V. Ramachandaran, N. S. Dalal, “The Utility of the Single-Molecule Magnet Fe-8 as a Magnetic Resonance Imaging Contrast Agent Over a Broad Range of Concentration,” Polyhedron, vol. 26, pp. 2413-2419 (2007)

Figure 3. Heterodyne terahertz imaging and spectroscopy system Image Copyright Geoffrey Wheeler, 2007

Figure 1. Scanning electron micrograph of Figure 2. Model of phantom under engineered magnets, 3 micrometers in development by EEEL and the ISMRM diameter, for enhanced MRI contrast. Committee on Standards for Quantitative MRI. It will include traceable dimensions and magnetic contrast agents.

Contacts

John Moreland (303) 497-3641 [email protected]

Stephen Russek (303) 497-5097 [email protected]

Electronics and Electrical Engineering Laboratory 93 SUPERCONDUCTIVITY

Summary Description

Energy losses in the transmission The global market for super- mental Reactor (ITER), and in support of electricity from generation conductors is about $5 billion, largely of the Department of Energy’s High- plants to amount to over five dominated by superconducting Energy Physics percent. Underground electrical magnets for magnetic resonance program. NIST’s data on the distribution lines in cities are at imaging (MRI) machines. However, irreversible strain limit and

the limits of their current-carrying recent successful demonstration alternating-field losses of Nb3Sn capacities. These are examples of projects point to increasing superconductor wires have already problems that could be mitigated applications in power transmission impelled ITER to change its wire with superconductors. lines, fault current limiters, transfor- specifications and heat-treatment The Superconductivity Program mers, synchronous condensers, schedule. The reason strain is such an conducts enabling research in magnetic devices, and important parameter is that, in most superconductivity for energy, other components for the electrical applications, superconductors are power grid reliability, medical power grid. Applications in proton subject to powerful Lorentz forces instruments, and fundamental radiation cancer treatments are also due to the current they carry in the physics. The program has a emerging. Measurements to charac- magnetic field of neighboring wires. worldwide reputation for its terize superconductors require These forces strain the wires, usually measurements of the effects of specialized expertise, and the to their detriment. mechanical strain and measurements must be reliable in Recent research in this program has temperature on the ability of order to solve engineering problems shown that the reduction of critical superconductor wires to carry that prevent wider use of both current with compressive strain in the extremely high current. conventional and high-temperature high-temperature Y-Ba-Cu-O super- Additionally, the program superconductors. conduc tor, which is being developed develops standard measurement To further its unique role as the de for electric transmission lines, is techniques and international facto reference laboratory for super - intrinsic to the superconductor grains. documentary standards for conductor critical current measure- In fact, the reversible strain effect in measurements to characterize ments, the program recently single-crystal thin films is comparable superconductors. It provides developed the world’s first high- to that of multi-granular Y-Ba-Cu-O quality assurance and reference current unified apparatus to measure coated conductors. This could have data for commercial and critical current as a function of strain, profound implications for the prototype high-temperature and temperature, and magnetic field. It is development of practical high- low-temperature being used for fundamental research temperature superconductors. The superconductors. at NIST, the U.S. contribution to the Superconductivity Program has deve- International Thermonuclear Experi - loped an apparatus to measure the

94 Electronics and Electrical Engineering Laboratory critical current of Y-Ba-Cu-O coated development of high-temperature conductors as a function of strain, superconductors has shown how to temperature, magnetic field, and prevent Y-Ba-Cu-O from delaminating magnetic field angle. Other research from their metal substrates when in support of the commercial under strain.

Major Accomplishments

• Designed and constructed a unified temperature-strain apparatus. Figure 1. Unified apparatus for the measurement • Demonstrated that the reversible strain effect in Y-Ba-Cu-O is intragranular of superconductor critical-current density as a in origin. function of magnetic field, mechanical strain, and • Developed a model to describe the reversible strain effect in Y-Ba-Cu-O grain temperature. boundaries. • Constructed new electromechanical test structures for second-generation, high- temperature superconductors, including a new apparatus to measure the strain effect in variable magnetic-field angles. • Showed how low irreversible strain limits could explain serious damage in ITER prototype magnets.

• Formulated a scaling law for the flux pinning force in MgB2 superconductors. • Updated 12 International Electrotechnical Commission (IEC) standards, including Figure 2. Two - spring sample holders. measures of uncertainty. Superconductor wires are soldered to the outer circumference of the springs. Torque applied to the spring puts the wires into tension or compression. Selected Publications

• D. C. van der Laan, J. W. Ekin, “Large Intrinsic Effect of Axial Strain on the Critical Current of High-Temperature Superconductors for Electric Power Applications,” Applied Physics Letters, vol. 90, 052506 (2007) • N. Cheggour, J. W. Ekin, L. F. Goodrich, “Critical-Current Measurements on an ITER

Nb3Sn Strand: Effect of Axial Tensile Strain,” IEEE Transactions on Applied Superconductivity, vol. 17, pp. 1366-1369 (2007) • L. F. Goodrich, N. Cheggour, J. W. Ekin, T. C. Stauffer, “Critical-Current

Measurements on ITER Nb3Sn Strands: Effect of Temperature,” IEEE Transactions on Applied Superconductivity, vol. 17, pp. 1398-1401 (2007) Figure 3. Upper part of new high-current apparatus. The worm gear that is applied to torque the spring can be seen through the window.

Figure 4. Critical-current Contact measurement of a single- crystal thin film of Y-Ba- Loren Goodrich Cu-O deposited on a

SrTiO3 crystal. Axial (303) 497-3143 compressive strain is applied by bending the [email protected] beam.

Electronics and Electrical Engineering Laboratory 95