Transistors to Integrated Circuits Howar
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
High Performance Power Distribution Networks with On-Chip Decoupling Capacitors for Nanoscale Integrated Circuits
High Performance Power Distribution Networks with On-Chip Decoupling Capacitors for Nanoscale Integrated Circuits by Mikhail Popovich Submitted in Partial Ful¯llment of the Requirements for the Degree Doctor of Philosophy Supervised by Professor Eby G. Friedman Department of Electrical and Computer Engineering The College School of Engineering and Applied Sciences University of Rochester Rochester, New York 2007 ii It has become appallingly obvious that our technology has exceeded our humanity. | Albert Einstein iii Dedication This work is dedicated to my parents, Mr. Evgeniy Antonovich and Mrs. Lyud- mila Mikhailovna, my wife Oksana, and my daughter Elizabeth Michelle. iv Curriculum Vitae Mikhail Popovich was born in Izhevsk, Russia in 1975. He received the B.S. degree in electrical engineering from Izhevsk State Technical University, Izhevsk, Russia in 1998, and the M.S. degree in electrical and computer engineering from the University of Rochester, Rochester, NY in 2002, where he is completing the Ph.D. degree in electrical engineering. He was an intern at Freescale Semiconductor Corporation, Tempe, AZ, in the summer 2005, where he worked on signal integrity in RF and mixed-signal ICs and developed design techniques and methodologies for placing distributed on-chip de- coupling capacitors. His professional experience also includes characterization of sub- strate and interconnect crosstalk noise in CMOS imaging circuits for the Eastman Kodak Company, Rochester, NY. He has authored a book and several conference and journal papers in the areas of power distribution networks in CMOS VLSI circuits, placement of on-chip decoupling capacitors, and the inductive properties of on-chip v interconnect. His research interests are in the areas of on-chip noise, signal integrity, and interconnect design including on-chip inductive e®ects, optimization of power distribution networks, and the design of on-chip decoupling capacitors. -
Introduction to the Course. in This Lecture I Would Try to Set the Course in Perspective
Introduction to the course. In this lecture I would try to set the course in perspective. Before we embark on learning something, it is good to ponder why it would be interesting, besides the fact that it can fetch useful course credits. What do you understand by VLSI? In retrospect, integrated circuits having 10s of devices were called small scale integrated circuits (SSI), a few hundreds were called medium scale few thousands large scale. The game stopped with VLSI as people lost the count (not really). What does the word VLSI bring to your mind? Discussion to follow. What do you understand by technology? Discussion to follow. Technology is the application of scientific knowledge for practical purposes. For example, why you may not call VLSI circuit design as VLSI technology? This is by convention in the semiconductor business research and business community. The convention is to treat fabrication technology as the “technology”. In this course we would discuss and try to learn how Silicon Integrated Circuits are fabricated. Integrated circuits are fabricated by a sequence of fabrication steps called unit processes. A unit process would add to or subtract from a substrate. Examples of unit processes can be cleaning of a wafer, deposition of a thin film of a material and so on. The unit processes are not uniquely applied to VLSI fabrication only. I can combine several of these unit processes to make solar cells. I can do same for making MEMS devices. So the unit processes can be thought of as pieces in a jigsaw puzzles. The outcome would depend on how you sequence the unit processes. -
CHAPTER 8: Diffusion
1 Chapter 8 CHAPTER 8: Diffusion Diffusion and ion implantation are the two key processes to introduce a controlled amount of dopants into semiconductors and to alter the conductivity type. Figure 8.1 compares these two techniques and the resulting dopant profiles. In the diffusion process, the dopant atoms are introduced from the gas phase of by using doped-oxide sources. The doping concentration decreases monotonically from the surface, and the in-depth distribution of the dopant is determined mainly by the temperature and diffusion time. Figure 8.1b reveals the ion implantation process, which will be discussed in Chapter 9. Generally speaking, diffusion and ion implantation complement each other. For instance, diffusion is used to form a deep junction, such as an n-tub in a CMOS device, while ion implantation is utilized to form a shallow junction, like a source / drain junction of a MOSFET. Boron is the most common p-type impurity in silicon, whereas arsenic and phosphorus are used extensively as n-type dopants. These three elements are highly soluble in silicon with solubilities exceeding 5 x 1020 atoms / cm3 in the diffusion temperature range (between 800oC and 1200oC). These dopants can be introduced via several means, including solid sources (BN for B, As2O3 for As, and P2O5 for P), liquid sources (BBr3, AsCl3, and POCl3), and gaseous sources (B2H6, AsH3, and PH3). Usually, the gaseous source is transported to the semiconductor surface by an inert gas (e.g. N2) and is then reduced at the surface. 2 Chapter 8 Figure 8.1: Comparison of (a) diffusion and (b) ion implantation for the selective introduction of dopants into a semiconductor substrate. -
MOSFET - Wikipedia, the Free Encyclopedia
MOSFET - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/MOSFET MOSFET From Wikipedia, the free encyclopedia The metal-oxide-semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET), is by far the most common field-effect transistor in both digital and analog circuits. The MOSFET is composed of a channel of n-type or p-type semiconductor material (see article on semiconductor devices), and is accordingly called an NMOSFET or a PMOSFET (also commonly nMOSFET, pMOSFET, NMOS FET, PMOS FET, nMOS FET, pMOS FET). The 'metal' in the name (for transistors upto the 65 nanometer technology node) is an anachronism from early chips in which the gates were metal; They use polysilicon gates. IGFET is a related, more general term meaning insulated-gate field-effect transistor, and is almost synonymous with "MOSFET", though it can refer to FETs with a gate insulator that is not oxide. Some prefer to use "IGFET" when referring to devices with polysilicon gates, but most still call them MOSFETs. With the new generation of high-k technology that Intel and IBM have announced [1] (http://www.intel.com/technology/silicon/45nm_technology.htm) , metal gates in conjunction with the a high-k dielectric material replacing the silicon dioxide are making a comeback replacing the polysilicon. Usually the semiconductor of choice is silicon, but some chip manufacturers, most notably IBM, have begun to use a mixture of silicon and germanium (SiGe) in MOSFET channels. Unfortunately, many semiconductors with better electrical properties than silicon, such as gallium arsenide, do not form good gate oxides and thus are not suitable for MOSFETs. -
Which Pnictogen Is Best?† Cite This: New J
NJC PAPER Pnictogen bonding with alkoxide cages: which pnictogen is best?† Cite this: New J. Chem., 2019, 43,14305 Henry J. Trubenstein, ‡ Shiva Moaven, ‡ Maythe Vega, Daniel K. Unruh and Anthony F. Cozzolino * Pnictogen bonding is beginning to emerge as a useful supramolecular interaction. The design strategies for these systems are still in the early stages of development and much attention has been focused on the lighter pnictogens. Pnictogen bond donors can have up to three independent sites for binding which can result in triple pnictogen bonding. This has been observed in the self-assembly of antimony alkoxide cages, but not with the lighter congeners. This work reports structural characterization of an analogous arsenic alkoxide cage that engages in a single pnictogen bond and synthetic explorations of Received 14th July 2019, the bismuth congener. DFT calculations are used to evaluate the differences between the structures. Accepted 13th August 2019 Ultimately the partial charge on the pnictogen and the energy of the pnictogen lone pair dictate the DOI: 10.1039/c9nj03648b strength, orientation and number of pnictogen bonds that these cages form. Antimony cages strike the best balance between strength and directionality, allowing them to achieve triple pnictogen bonding rsc.li/njc where the other congeners do not. Introduction or bismuth.15–23 Recently, antimony centred PnBs have been purposefully designed into molecules to actively direct the self- A pnictogen bond (PnB), in analogy to a halogen or chalcogen assembly of reversed bilayer vesicles,24 enable anion binding bond (XB/HaB or ChB), is ‘‘the net attractive interaction between with applications in sensing and transport,25–28 self-assembly an electrophilic region associated with a [pnictogen] atom in a complex architectures through triple pnictogen bonding29 and molecular entity [the PnB donor] and a nucleophilic region in allow for supramolecular catalysis.30 These applications rely on another, or the same, molecular entity [the PnB acceptor].’’1 the predictable formation of PnBs. -
Transistors to Integrated Circuits
resistanc collectod ean r capacit foune yar o t d commercial silicon controlled rectifier, today's necessarye b relative .Th e advantage lineaf so r thyristor. This later wor alss kowa r baseou n do and circular structures are considered both for 1956 research [19]. base resistanc r collectofo d an er capacity. Parameters, which are expected to affect the In the process of diffusing the p-type substrate frequency behavior considerede ar , , including wafer into an n-p-n configuration for the first emitter depletion layer capacity, collector stage of p-n-p-n construction, particularly in the depletion layer capacit diffusiod yan n transit redistribution "drive-in" e donophasth f ro e time. Finall parametere yth s which mighe b t diffusion at higher temperature in a dry gas obtainabl comparee ear d with those needer dfo ambient (typically > 1100°C in H2), Frosch a few typical switching applications." would seriously damag r waferseou wafee Th . r surface woul e erodedb pittedd an d r eveo , n The Planar Process totally destroyed. Every time this happenee dth s e apparenlosexpressiowa th s y b tn o n The development of oxide masking by Frosch Frosch' smentiono t face t no , ourn o , s (N.H.). and Derick [9,10] on silicon deserves special We would make some adjustments, get more attention inasmuch as they anticipated planar, oxide- silicon wafers ready, and try again. protected device processing. Silicon is the key ingredien oxids MOSFEr it fo d ey an tpave wa Te dth In the early Spring of 1955, Frosch commented integrated electronics [22]. -
Donor Qubits in Silicon
04/09/2015 Experiments with spin qubits in siliconDonor and diamond qubits in silicon Gavin W Morley University of Warwick Gavin W Morley, Spin qubits in silicon and diamond, QuICC Warwick, August 2015 Experiments with spin qubits in silicon and diamond: overview • Lecture 1 – Magnetic resonance – Silicon • Lecture 2 – Silicon (cont.) Lab tours • Lecture 3 Friday morning – Diamond Gavin W Morley, Spin qubits in silicon and diamond, QuICC Warwick, August 2015 1 04/09/2015 Experiments with spin qubits in silicon and diamond: overview • Lecture 1 – Magnetic resonance 1. Prepare (spin Hamiltonian) 2. Control (electromagnetic pulses) 3. Measure (spin state readout) – Silicon Gavin W Morley, Spin qubits in silicon and diamond, QuICC Warwick, August 2015 – Magnetic resonance 1. Prepare (spin Hamiltonian) 2. Control (electromagnetic pulses) 3. Measure (spin state readout) Gavin W Morley, Spin qubits in silicon and diamond, QuICC Warwick, August 2015 2 04/09/2015 Magnetic resonance: prepare - put a spin ½ into a magnetic field H Ŝ Hamiltonian = ωS z with energy, ħ ωS = g µB B0 for g-factor, g ~ 2, Bohr magneton µB = e ħ/2me, electron spin S = ½ Energy m = ½ of a s spin Magnetic field, B0 ms = -½ Gavin W Morley, Spin qubits in silicon and diamond, QuICC Warwick, August 2015 Magnetic resonance: prepare - put a spin ½ into a magnetic field Larmor precession at angular frequency ωS Gavin W Morley, Spin qubits in silicon and diamond, QuICC Warwick, August 2015 3 04/09/2015 Magnetic resonance: prepare - put a spin ½ into a magnetic field Larmor precession -
Planar Process with Noyce’S Interconnection Via a Diffused Layer of Metal Conductors
Future Horizons Ltd Blakes Green Cottage TN15 0LQ, UK Tel: +44 1732 740440 Fax: +44 1732 608045 [email protected] www.futurehorizons.com Research Brief: 2019/01 – The Planar IC Process The Planar IC Process On 1 December 1957, Jean Hoerni, a Swiss physicist and Fairchild Semiconductor co-founder, recorded in his patent notebook an entry called "A method of protecting exposed p-n junctions at the surface of silicon transistors by oxide masking techniques." This was the first formal documentation of the planar semiconductor process, a radically new transistor design in which the oxide layer was left in place on the silicon wafer to protect the sensitive p-n junctions underneath. Focused on getting its first semiconductor devices into production, Fairchild did not pursue Hoerni’s planar approach at that time and it was not until 14 January 1959 that Hoerni finally wrote up his disclosure for what would become U.S. Patent 3025589. One week later, on 23 January 1959, Robert (Bob) Noyce, a fellow Fairchild co-founder, wrote up a disclosure for the planar IC. Fairchild’s first working planar IC was built some 16 months later in May 1960. Sixty years on, this technology remains the basis for virtually all semiconductor manufacturing today. The Early Days By the late 1950s, even though barely a decade old, transistors had already gone through several stages of development, including the material transition from germanium to silicon and the move from piece by piece to batch manufacturing through a simple photolithographic and Page 1 of 8 © Future Horizons 1989-2019, Reproduction Prohibited - All Rights Reserved The Planar IC Process The Global Semiconductor Industry Analysts Research Brief: 2019/01 etching technique known as the Mesa process. -
Donor-Acceptor Methods for Band Gap Reduction in Conjugated Polymers: the Role of Electron Rich Donor Heterocycles
DONOR-ACCEPTOR METHODS FOR BAND GAP REDUCTION IN CONJUGATED POLYMERS: THE ROLE OF ELECTRON RICH DONOR HETEROCYCLES By CHRISTOPHER A. THOMAS A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2002 Copyright 2002 by Christopher A. Thomas All rights reserved. ACKNOWLEDGMENTS I thank my parents, Nancy and Larry, for their continuous support and attempts to understand and encourage me during what has been simultaneously the most enjoyable and most stressful part of my life. They made this document possible by encouraging and par- ticipating in experiences that ensured I would have the backgound and interest in trying to figure out how the world works. The decision about whom to work for in graduate school is one of the events I have agonized the most about in my life. As promised, the graduate advisor-student relationship is a complicated entity consisting of advisor, boss, counselor and friend that can change its active role without warning. Despite this, I am positive that there is no other person that I would rather have worked with during this process. I especially appreciate being given an unusual amount of decision making and direction setting power in the projects I was involved with and the freedom to explore aspects of science that interested me even when they did not overlap cleanly with Professor Reynolds’ research interests or funding. For their major contributions to my enjoyment and interest in chemistry, I thank Joe Carolan for his contagious enthusiasm, and Joel Galanda, who immensely affected the three years of my life he was involved with my chemistry and physical science education. -
Donor-Acceptor Properties of Trivalent Phosphorus and Arsenic Ligands Larry James Vande Griend Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1975 Donor-acceptor properties of trivalent phosphorus and arsenic ligands Larry James Vande Griend Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Inorganic Chemistry Commons Recommended Citation Vande Griend, Larry James, "Donor-acceptor properties of trivalent phosphorus and arsenic ligands " (1975). Retrospective Theses and Dissertations. 5764. https://lib.dr.iastate.edu/rtd/5764 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While the most advanced technologcal means to photogaph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. 1. The sign or "terget" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necasitstsd cutung thru an image and du^icating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image. -
CHAPTER 1: Semiconductor Materials & Physics
Chapter 1 1 CHAPTER 1: Semiconductor Materials & Physics In this chapter, the basic properties of semiconductors and microelectronic devices are discussed. 1.1 Semiconductor Materials Solid-state materials can be categorized into three classes - insulators, semiconductors, and conductors. As shown in Figure 1.1, the resistivity of semiconductors, ρ, is typically between 10-2 and 108 Ω-cm. The portion of the periodic table related to semiconductors is depicted in Table 1.1. Figure 1.1: Typical range of conductivities for insulators, semiconductors, and conductors. Semiconductors can be composed of a single element such as silicon and germanium or consist of two or more elements for compound semiconductors. A binary III-V semiconductor is one comprising one element from Column III (such as gallium) and another element from Column V (for instance, arsenic). The common element and compound semiconductors are displayed in Table 1.2. City University of Hong Kong Chapter 1 2 Table 1.1: Portion of the Periodic Table Related to Semiconductors. Period Column II III IV V VI 2 B C N Boron Carbon Nitrogen 3 Mg Al Si P S Magnesium Aluminum Silicon Phosphorus Sulfur 4 Zn Ga Ge As Se Zinc Gallium Germanium Arsenic Selenium 5 Cd In Sn Sb Te Cadmium Indium Tin Antimony Tellurium 6 Hg Pd Mercury Lead Table 1.2: Element and compound semiconductors. Elements IV-IV III-V II-VI IV-VI Compounds Compounds Compounds Compounds Si SiC AlAs CdS PbS Ge AlSb CdSe PbTe BN CdTe GaAs ZnS GaP ZnSe GaSb ZnTe InAs InP InSb City University of Hong Kong Chapter 1 3 1.2 Crystal Structure Most semiconductor materials are single crystals. -
Lecture 7: Extrinsic Semiconductors - Fermi Level
Lecture 7: Extrinsic semiconductors - Fermi level Contents 1 Dopant materials 1 2 EF in extrinsic semiconductors 5 3 Temperature dependence of carrier concentration 6 3.1 Low temperature regime (T < Ts)................7 3.2 Medium temperature regime (Ts < T < Ti)...........8 1 Dopant materials Typical doping concentrations in semiconductors are in ppm (10−6) and ppb (10−9). This small addition of `impurities' can cause orders of magnitude increase in conductivity. The impurity has to be of the right kind. For Si, n-type impurities are P, As, and Sb while p-type impurities are B, Al, Ga, and In. These form energy states close to the conduction and valence band and the ionization energies are a few tens of meV . Ge lies the same group IV as Si so that these elements are also used as impurities for Ge. The ionization energy data n-type impurities for Si and Ge are summarized in table 1. The ionization energy data for p-type impurities for Si and Ge is summarized in table 2. The dopant ionization energies for Ge are lower than Si. Ge has a lower band gap (0.67 eV ) compared to Si (1.10 eV ). Also, the Table 1: Ionization energies in meV for n-type impurities for Si and Ge. Typical values are close to room temperature thermal energy. Material P As Sb Si 45 54 39 Ge 12 12.7 9.6 1 MM5017: Electronic materials, devices, and fabrication Table 2: Ionization energies in meV for p-type impurities. Typical values are comparable to room temperature thermal energy.