DOCSLIB.ORG

Chemical Vapor Deposition

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chemical Vapor Deposition University of Iowa Microfabrication Facility (UIMF) Optical Science and Technology Center UIMF Training – Module 2 Plasma Etching and Thin-film technologies Aju Jugessur Ph.D. Outline Plasma Etching Technologies Thin-film deposition technologies Applications 2 Outline • Introduction • Principles of dry-etching • Etch plasmas: DC and RF • Physical and Chemical etching • Etching reactors 3 Dry Etching A family of methods by which a solid surface is etched in the gas phase by ion bombardment, chemically by a chemical reaction with reactive species at the surface or could be a combination of physical and chemical mechanisms. The need for better control of the CD dimension triggered a major research and development in all types of dry-etching processes based on plasmas. Dry-etch – physical: ions, momentum transfer, anisotropic, More widely used for small features Combination of physical and chemical – Combines both directionality and selectivity Degree of anisotropy controlled by plasma conditions 4 Relationship between the various dry etching techniques Dry-etching Glow-discharge methods Ion beam methods – – diode set-up triode set-ups Physical etching only Plasma etching Reactive ion Sputter etching Ion milling Ion beam Reactive ion etching assisted chem. beam etching sputtering etch 0.2-2 Torr 0.01- 0.2 Torr 10-3 to 10-4 Torr Low energy High energy High energy No reactive Reactive Some reactive bombardment bombardment bombardment neutrals neutrals added neutrals 5 Some common Dry etching systems CAIBE RIBE IBE MIE MERIE RIE Barrel PE etching Pressure ~ 10-4 ~10-4 ~10-4 10-3 10-3 – 10-3-10-1 10-1-100 10-1-10 1 (Torr) -10-2 10-2 Etch Chem./ Chem. Phys. Phys. Chem/ Chem/ chem Chem Mechanism phys. /phys. phys phys SelecDvity good good poor poor good good excellent good Profile Anis. Anis. Anis. Anis. Anis. Iso. Or Iso. Iso. Or Or iso. anis. anis. CAIBE: chemically assisted ion beam etching; MERIE: magnetically ehnanced reactive ion etching; PE: plasma etching; RIBE: reactive ion beam etching; RIE: reactive ion etching; MIE: magnetically enhanced ion etching 6 Directionality of etching process volatile Volatile product volatile neutral ion ion neutral product neutral product + + ion + inhibitor Ion-enhanced Sputtering Chemical Ion-enhanced energetic inhibitor Physical and chemical Side-walls are protected Mask is etched most Chemical etching at etching at high voltage from undercutting by rapidly near mask corner. low voltage and high and low pressure a surface species, Slope becomes less steep, pressure leads to isotropic Directional anisotropy e.g. a polymer not all ions reaching bottom etch and lateral undercuts parallel to sides 7 Etch plasmas: DC and RF Plasmas A plasma may be considered as a region of a gas discharge which contains essentially equal quantities of positive and negative charge associated with various species of charge carrier. DC plasmas The simplest plasma reactor consists of opposed parallel plates electrodes in a chamber maintained at low pressure, 0.001 to 1 Torr. Applying a 1.5 kV between anode and V cathode separated by 15 cm results Vp cathode in a 100 V/cm field. 0 Anode ions Electrical breakdown of Ar gas occur electrons when accelerated electrons in field transfer an amount of kinetic energy to overcome the argon ionizing potential (15.7 ev). V e Such energetic collisions generate a second free e- and +ve ion, creating an avalanche of ions and electrons resulting in a gas Plasma sheath breakdown emitting a characteristic glow. 8 Kinetic theory – random velocity distribution of flux of ions and electrons n < v > j = i,e i,e i,e 4 Where ji,e : random velocity distribution of flux of ions and electrons ni,e :densities of ions and electrons vi,e : average velocities Ions are heavier than electrons (~ 4000 to 100,000 heavier); average velocity of electrons is larger implying larger electron flux Bombarding energy of ion is proportional to the potential difference between plasma potential and surface being struck by ions. 9 RF plasmas In an RF-generated plasma, a radio frequency voltage is applied between the two electrodes causing the free electrons to oscillate and collide with gas molecules leading to a sustainable plasma. RF-excited plasmas can be sustained without relying on the emission of secondary electrons from the target. Lower pressure than DC ~ 40 mTorr – more anisotropy RF allows etching of dielectrics as well as metals. Matching Ground shield network cathode 13.56 mHz RF electrode with target RF generator, 1.2 kW anode Substrate holder for deposition Vacuum chamber wall 10 11 12 An RF plasma, formed at low gas pressures, consists of positive cations, negative ions, radicals, vibrationally excited polyatomic species and photons (create the plasma glow). The RF frequency chosen is 13.56 MHz because it does not interfere with radio-transmitted signals, RF power supply is between 1-2 kW. When initiating a plasma arc, electrons charge up the capacitively coupled electrode; since no charge can be transferred over the capacitor the electrode surface acquires a –ve DC bias Energy of charge particles bombarding the surface in a glow discharge is determined by 3 different potentials established in the reaction chamber Plasma potential, Vp The self-bias Vdc The bias on the capacitively coupled electrode (VRF)pp Max. energy of +ve ions striking a substrate placed on cathode is proportional to E = e(V +V ) = eV max DC p T 13 Types of physical Etching • Physical sputtering • Reactive Ion etching • Plasma etching Physical Sputtering (& Ion Beam Milling) Higher < 100 mTorr • physical momentum transfer Excitation • directional etch – anisotropic possible energy • poor selectivity • radiation damage possible Reactive Ion Etching • physical (ion) and chemical 100 mTorr • directional range • more selective than sputtering Plasma etching • chemical, thus faster by 10-10000x • isotropic • more selective Higher • less prone to radiation damage pressure 14 Schematic view of the microscopic processes occurring during the dry-etch of a silicon wafer redisposition 8. Pump out Incoming gas Gas in 1. Electron impact To pump reactions plasma Etchant 7. Transport into Key Steps: creation bulk of gas 1. Generation of reactive species 2. Transport to 2. Species transported to surface Surface + gas- phase reactions by diffusion Gaseous 3. Adsorption at surface product 4. Chemical reaction – formation of Gaseous reactants volatile products sheath + + + + 3 4. Etchant/film 5. desorption 5. Product desorption Adsorbed reactants reaction 6. Ion bombardment Film on Desorption: substance release from wafer or through a surface wafer Adsorption:adhesion of ions atoms to surface 15 16 17 Produces electric field lines from a helical resonator combined with an electrostatic shield to produce electric field lines that are circumferential in response to the RF field 18 19 20 Etch Parameters within control • Gas composition: types and ratios • Flows: -affecting generation of active species -affect consumption of active species -affect removal rate of reactive by-products -affect residence time • Pressure • Power/Bias • Temperature • Magnetic field 21 Ex: Dry etching - Reactive Ion Etching III-V III-V etch PECVD etch silica etch Mask 200 nm 200 nm 200 nm Gas manifold PMMA SiO2 SiO2 Gases CHF3 SiCl4:O2 SiCl4:O2 Process Corrected Standard 15:0 15:1 chamber flow process vent Plasma and (sccm) wafer monitoring RF forward 250 250 Wafer heating power (W) and cooling Pressure Open Open Pump N 2 (mTorr) valve valve exhaust (5 mT) (5mT) Turbo Etch time 12 17 20 pump (mins) Rf generator Plate silicon silicon carrier Epitaxial 850 nm 1300 nm structure wafer wafer 22 Chamber contamination → micro-masking - grass formation grass 130 nm Al0.6Ga0.4As grass500 nm GaAs 1800 nm Al0.6Ga0.4As Dry-etch optimization Side wall passivation O2 SiCl :O 4 2 500 nm 15:1 SiCl 4 → SiCl 4−x + Cl x SiCl4 +O2 → SiO2 + mCl4 x = 1,2 23 Parameter control in plasma processes The challenge: to implement a useful and reproducible Excitation frequency Gas flow rate etch-process involves the control of a large number of Excitation power parameters which affect the n , f(e), Geometrical factors e process N, (surface) τ Use of factorial Nature of discharge gas Pumping speed experimental design techniques very useful Consequences Geometrical factors Nature of surface of plasma- (surface) surface interaction Temperature of surface Potential of surface 24 25 Etching profiles in physical etching Ideal result in dry or wet etching is high-fidelity transfer of mask pattern onto substrate, with no distortion of CDs. Ion etching or ion milling do not lead to undercutting of the mask but the walls of an etched cut are not necessarily vertical. Faceting due to angle- Trenching dependent sputter rate Facets in mask Faceting – sputtering creates angles features. An Trenching – ditching due to glancing incidence of ions angled facet (~60°) in the resist propagates as the mask is eroded away. Sloped walls may be created in the underlying substrate 26 Redeposition Backscattering Angular distribution of incident ions Redeposited material Back scattering Angular distribution of ions Redeposition of material sputtered Backscattering is a form of Off-vertical ion trajectories can from bottom of a trench. By tilting redeposition, associated with also be caused by sheath and rotating the substrate during involatile etch products. A fraction scattering and field non- etching, etch profiles can be of sputtered and involatile species uniformities. improved. from the surface is backscattered onto substrate after several collisions with gas species. 27 28 Etch reactor configurations • Barrel etcher • Parallel-electrode (planar) reactors • Hexode etchers (cylindrical batch etch reactors) • Single wafer etchers 29 Loading effects – Uniformity and Nonuniformity Dry-etch – number of radicals in the plasma is in same range as the number of atoms to be removed. Wet-etch – number of etchant molecules might is 105 times higher than the number of atoms to be removed.
Load more

Recommended publications
  • MEMS Technology for Physiologically Integrated Devices
    A BioMEMS Review: MEMS Technology for Physiologically Integrated Devices AMY C. RICHARDS GRAYSON, REBECCA S. SHAWGO, AUDREY M. JOHNSON, NOLAN T. FLYNN, YAWEN LI, MICHAEL J. CIMA, AND ROBERT LANGER Invited Paper MEMS devices are manufactured using similar microfabrica- I. INTRODUCTION tion techniques as those used to create integrated circuits. They often, however, have moving components that allow physical Microelectromechanical systems (MEMS) devices are or analytical functions to be performed by the device. Although manufactured using similar microfabrication techniques as MEMS can be aseptically fabricated and hermetically sealed, those used to create integrated circuits. They often have biocompatibility of the component materials is a key issue for moving components that allow a physical or analytical MEMS used in vivo. Interest in MEMS for biological applications function to be performed by the device in addition to (BioMEMS) is growing rapidly, with opportunities in areas such as biosensors, pacemakers, immunoisolation capsules, and drug their electrical functions. Microfabrication of silicon-based delivery. The key to many of these applications lies in the lever- structures is usually achieved by repeating sequences of aging of features unique to MEMS (for example, analyte sensitivity, photolithography, etching, and deposition steps in order to electrical responsiveness, temporal control, and feature sizes produce the desired configuration of features, such as traces similar to cells and organelles) for maximum impact. In this paper, (thin metal wires), vias (interlayer connections), reservoirs, we focus on how the biological integration of MEMS and other valves, or membranes, in a layer-by-layer fashion. The implantable devices can be improved through the application of microfabrication technology and concepts.
    [Show full text]
  • Design of a Microelectronic Manufacturing Laboratory
    2006-1635: DESIGN OF A MICROELECTRONIC MANUFACTURING LABORATORY Stilson Applin, Montana State University Todd Kaiser, Montana State University Page 11.407.1 Page © American Society for Engineering Education, 2006 Design of a Microelectronic Manufacturing Laboratory Abstract The design of an undergraduate microelectronic manufacturing laboratory for teaching will be described in the following paper. This laboratory emphasizes learning the processes of semiconductor manufacturing and clean room protocol. The laboratory is housed in a 500 square foot, class 10,000 facility. In the laboratory the students, with a junior standing and a science based background, will use a pre-made six mask set to create P and N type transistors as well as inverters and diodes. The students will be conducting oxidization, RCA clean, photolithography, etching, diffusion, metallization and other processes. A brief description of these processes and the methods used to teach them will also be described. In addition to these processes students will also learn about clean room protocol, chemical safety, and testing devices. All of these skills will be marketable to future employers and graduate schools. These same skills and processes will be covered in a seminar course for educators, with the main purpose of inspiring the high school teachers to teach about semiconductor manufacturing. The cost effective design is what makes the laboratory unique. The expenditure control is important due to the size of the Electrical Engineering department. The department has only 250 undergraduates and 40 graduate students, thus internal funding is difficult to obtain. A user fee paid by the students will cover the funding. This fee will be small and manageable for any college student.
    [Show full text]
  • Advanced Solar Technology Sample
    ADVANCED SOLAR TECHNOLOGY SAMPLE TECHNOLOGY ACQUISITION REPORT CONTENTS Technology 1: Microsystems Enabled Photovoltaics (MEPV) - Photovoltaic solar concentrator ............... 4 Technology 2: Method and apparatus for integrating an infrared (ir) photovoltaic cell on a thin film photovoltaic cell ............................................................................................................................................ 7 Technology 3: Photovoltaic cells with quantum dots with built-in-charge and methods of making same 10 Technology 4: Super-transparent electodes for photovoltaic applications ................................................. 13 Technology 5: Optical concentrator and associated photovoltaic devices ................................................. 15 Technology 6: Hybrid photovoltaic devices and applications thereof ........................................................ 18 Technology 7: Methods of manufacturing photovoltaic electrodes ............................................................ 20 Technology 8: Thin film photovoltaic cell structure, nanoantenna, and method for manufacturing ......... 23 Technology 9: Apparatuses, systems and methods for cleaning photovoltaic devices .............................. 26 Technology 10: Photovoltaic structures having a light scattering Interface layer and methods of making the same ....................................................................................................................................................... 28 Technology 11: Rapid thermal
    [Show full text]
  • A Review of Current Methods in Microfluidic Device Fabrication And
    inventions Review A Review of Current Methods in Microfluidic Device Fabrication and Future Commercialization Prospects Bruce K. Gale * ID , Alexander R. Jafek ID , Christopher J. Lambert ID , Brady L. Goenner, Hossein Moghimifam, Ugochukwu C. Nze ID and Suraj Kumar Kamarapu ID Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112, USA; [email protected] (A.R.J.); [email protected] (C.J.L.); [email protected] (B.L.G.); [email protected] (H.M.); [email protected] (U.C.N.); [email protected] (S.K.K.) * Correspondence: [email protected]; Tel.: +1-801-585-5944 Received: 30 June 2018; Accepted: 20 August 2018; Published: 28 August 2018 Abstract: Microfluidic devices currently play an important role in many biological, chemical, and engineering applications, and there are many ways to fabricate the necessary channel and feature dimensions. In this review, we provide an overview of microfabrication techniques that are relevant to both research and commercial use. A special emphasis on both the most practical and the recently developed methods for microfluidic device fabrication is applied, and it leads us to specifically address laminate, molding, 3D printing, and high resolution nanofabrication techniques. The methods are compared for their relative costs and benefits, with special attention paid to the commercialization prospects of the various technologies. Keywords: microfabrication; nanofabrication; microfluidics; nanofluidics; 3D printing; laminates; molding 1. Introduction Microfluidics is a growing field of research which pertains to the manipulation of fluids on the microscale level, and it is identified most commonly by devices with critical dimensions of less than 1 mm.
    [Show full text]
  • Microfabrication and Microfluidics for 3D Brain-On-Chip
    Microfabrication and microfluidics for 3D brain-on-chip Bart Schurink Microfabrication and microfluidics for 3D brain-on-chip Bart Schurink i Members of the committee: Chairman Prof. dr. ir. J.M.W. Hilgenkamp (voorzitter) Universiteit Twente Promotor Prof. dr. J.G.E. Gardeniers Universiteit Twente Co-promotor/supervisor Dr. R. Luttge Universiteit Eindhoven Members Prof. dr. J.C.T. Eijkel University of Twente Prof. dr. H.B.J. Karperien University of Twente Prof. dr. A.S. Holmes Imperial College London Prof. dr. ir. J.M.J. den Toonder Technical University of Eindhoven Prof. dr. ir. R. Dekker Delft University of Technology The work in this thesis was carried out in the Mesoscale Chemical Systems group and MESA+ Institute for Nanotechnology, University of Twente. It is part of the MESOTAS project financially supported by ERC, Starting Grant no. 280281 Title: Microfabrication and microfluidics for 3D brain-on-chip Author: Bart Schurink ISBN: 978-90-365-4142-8 DOI: 10.3990/1.9789036541428 Publisher: Gildeprint, Enschede, The Netherlands Copyright © 2016 by Bart Schurink, Enschede, The Netherlands. No part of the this book may be copied, photocopied, reproduced, translated or reduced to any electronic medium or machine-readable form, in whole or in part, without specific permission of the author. ii Microfabrication and microfluidics for 3D brain-on-chip PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Twente, op gezag van de rector magnificus, Prof. dr. H. Brinksma, volgens besluit van het College voor Promoties in het openbaar te verdedigen op donderdag 23 juni 2016 door Bart Schurink Geboren op 6 november 1982 te Oldenzaal, Nederland iii Dit proefschrift is goedgekeurd door de promotor: Prof.
    [Show full text]
  • A Technology Overview and Applications of Bio-MEMS
    INSTITUTE OF SMART STRUCTURES AND SYSTEMS (ISSS) JOURNAL OF ISSS J. ISSS Vol. 3 No. 2, pp. 39-59, Sept. 2014. REVIEW ARTICLE A Technology Overview and Applications of Bio-MEMS Nidhi Maheshwari+, Gaurav Chatterjee+, V. Ramgopal Rao. Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai, India-400076. Corresponding Author: [email protected] + Both the authors have contributed equally. Keywords: Abstract Bio-MEMS, immobilization, Miniaturization of conventional technologies has long cantilever, micro-fabrication, been understood to have many benefits, like: lower cost of biosensor. production, lower form factor leading to portable applications, and lower power consumption. Micro/Nano fabrication has seen tremendous research and commercial activity in the past few decades buoyed by the silicon revolution. As an offset of the same fabrication platform, the Micro-electro-mechanical- systems (MEMS) technology was conceived to fabricate complex mechanical structures on a micro level. MEMS technology has generated considerable research interest recently, and has even led to some commercially successful applications. Almost every smart phone is now equipped with a MEMS accelerometer-gyroscope system. MEMS technology is now being used for realizing devices having biomedical applications. Such devices can be placed under a subset of MEMS called the Bio-MEMS (Biological MEMS). In this paper, a brief introduction to the Bio-MEMS technology and the current state of art applications is discussed. 1. Introduction Generally, the Bio-MEMS can be defined as any The interdisciplinary nature of the Bio-MEMS research is system or device, which is fabricated using the highlighted in Figure 2. This highlights the overlapping of micro-nano fabrication technology, and used many different scientific disciplines, and the need for a healthy for biomedical applications such as diagnostics, collaborative effort.
    [Show full text]
  • Design and Simulation of an RF-MEMS Switch and Analysis of Its
    Advances in Science, Technology and Engineering Systems Journal Vol. 3, No. 1, 76-81 (2018) ASTESJ www.astesj.com ISSN: 2415-6698 Special issue on Advancement in Engineering Technology Design and Simulation of an RF-MEMS Switch and analysis of its Electromagnetic aspect in realtion to stress Amna Riaz*,1, Muhammad Umair Javed Ilam Sindhu2, Tahir Zaidi3 1University of Azad Jammu and Kashmir, Department of Electrical Engineering, Muzaffarabad, 13100, Pakistan 2Memorial University of Newfoundland, Department of Electrical and Computer Engineering, A1B 3X5, Canada 3National University of Science and Technology, Department of Electrical Engineering Department, EME College, 13100, Pakistan A R T I C L E I N F O A B S T R A C T Article history: Microelectromechanical Systems (MEMS) are devices made up of several electrical and Received: 31 May, 2017 mechanical components. They consist of mechanical functions (sensing, thermal, inertial) Accepted: 05 September, 2017 and electrical functions (switching, decision making) on a single chip made by Online: 30 January, 2018 microfabrication methods. These chips exhibit combined properties of the two functions. The size of system has characteristic dimensions less than 1mm but more than 1μm. The Keywords : configuration of these components determine the final deliverables of the switch. MEMS RF-MEMS can be designed to meet user requirements on any level from microbiological application Residual Stresses such as biomedical transducers or tissue engineering, to mechanical systems such as Coplanar waveguide microfluidic diagnoses or chemical fuel cells. The low cost, small mass and minimal power Skin depth consumption of the MEMS makes it possible to readily integrate to any kind of system in Return loss any environment.
    [Show full text]
  • Microfabrication of Plastic-PDMS Microfluidic Devices Using Polyimide Release Layer and Selective Adhesive Bonding
    BNL-114324-2017-JA Microfabrication of Plastic-PDMS Microfluidic Devices Using Polyimide Release Layer and Selective Adhesive Bonding S. Wang, M. Lu Submitted to the Journal of Micromechanics and Microengineering March 2017 Center for Functional Nanomaterials Brookhaven National Laboratory U.S. Department of Energy USDOE Office of Science (SC), Basic Energy Sciences (SC-22) Notice: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE- SC0012704 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or any third party’s use or the results of such use of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof or its contractors or subcontractors. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
    [Show full text]
  • Techniques and Considerations in the Microfabrication of Parylene C Microelectromechanical Systems
    micromachines Review Techniques and Considerations in the Microfabrication of Parylene C Microelectromechanical Systems Jessica Ortigoza-Diaz 1, Kee Scholten 1 ID , Christopher Larson 1 ID , Angelica Cobo 1, Trevor Hudson 1, James Yoo 1 ID , Alex Baldwin 1 ID , Ahuva Weltman Hirschberg 1 and Ellis Meng 1,2,* 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA; [email protected] (J.O.-D.); [email protected] (K.S.); [email protected] (C.L.); [email protected] (A.C.); [email protected] (T.H.); [email protected] (J.Y.); [email protected] (A.B.); [email protected] (A.W.H.) 2 Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA * Correspondence: [email protected]; Tel.: +1-213-740-6952 Received: 31 July 2018; Accepted: 18 August 2018; Published: 22 August 2018 Abstract: Parylene C is a promising material for constructing flexible, biocompatible and corrosion- resistant microelectromechanical systems (MEMS) devices. Historically, Parylene C has been employed as an encapsulation material for medical implants, such as stents and pacemakers, due to its strong barrier properties and biocompatibility. In the past few decades, the adaptation of planar microfabrication processes to thin film Parylene C has encouraged its use as an insulator, structural and substrate material for MEMS and other microelectronic devices. However, Parylene C presents unique challenges during microfabrication and during use with liquids, especially for flexible, thin film electronic devices. In particular, the flexibility and low thermal budget of Parylene C require modification of the fabrication techniques inherited from silicon MEMS, and poor adhesion at Parylene-Parylene and Parylene-metal interfaces causes device failure under prolonged use in wet environments.
    [Show full text]
  • Creating a Solar Cell Array from a Single Silicon Wafer
    Creating a Solar Cell Array from a Single Silicon Wafer Samyukta Gade – Materials Engineering Roderick Marstell – Materials Engineering Advisor: Dr. Richard Savage College of Engineering California Polytechnic State University San Luis Obispo 2012 Approval Page Project Title: Creating a Solar Cell Array from a Single Silicon Wafer Author: Samyukta Gade, Roderick Marstell Date Submitted: 6-1-2012 CAL POLY STATE UNIVERSITY Materials Engineering Department Since this project is a result of a class assignment, it has been graded and accepted as fulfillment of the course requirements. Acceptance does not imply technical accuracy or reliability. Any use of the information in this report, including numerical data, is done at the risk of the user. These risks may include catastrophic failure of the device or infringement of patent or copyright laws. The students, faculty, and staff of Cal Poly State University, San Luis Obispo cannot be held liable for any misuse of the project. Prof. Richard Savage ____________________________ Faculty Advisor Signature Prof. Trevor Harding ____________________________ Department Chair Signature ii Acknowledgments We would like to thank Dr. Savage for all the support he has given us during the design, planning, and execution. There is no way that we would have completed this project without his assistance. We also want to thank Elizabeth Brooks, Buddy Bump, and Nicolas Wiswell. They were instrumental in processing support and, in the case of Buddy, made testing possible. iii Abstract Two different processes to create multi-celled solar panels from single wafers were made and implemented. To do this, the cells must not have a common ground, and both designs use different approaches to solve this problem.
    [Show full text]
  • MEMS and MEMS Microfabrication
    MEMS and MEMS Microfabrication MEMS and MEMS Microfabrication What are MEMS? Micro Electro-Mechanical Systems (MEMS) are a technology field that can be defined as microscopic implementations of mechanical and electro-mechanical elements (ie devices and structures) that are made using the techniques of Microfabrication. These devices are widely used in everyday products such as Smartphones (microphones, gyroscope, magnetometer), Wearable devices (accelerometers, heart rate sensors), Automotive (pressure, flow, acceleration sensors) and many other applications. MEMS are everywhere Smartphones and Tablets Wearable Devices Automotive What are the differences between MEMS and Semiconductors? MEMS and Semiconductors are completely different technologies. Semiconductor devices make use of the electronic properties of materials such as Silicon. These properties have meant semiconductors now are the basis of most advanced electronics. Semiconductors have progressed since the 1960’s to the sophisticated microprocessors, memory chips, and wireless components that enable our Laptops, Tablets, and Smartphones, and the Internet of Things. Synergistically combined with Semiconductors, MEMS are Lab-on-a-chip essential in allowing devices to sense and physically interact with the world. MEMS devices can vary from a relatively simple structure to extremely complex electromechanical systems with multiple moving elements under the control of integrated microelectronics. MEMS can capture physical data such as measuring temperature, air pressure, magnetic fields and radiation. MEMS may use semiconductor material for its electronic qualities, but also utilize its mechanical properties. Silicon can be flexed with almost no energy dissipation, thereby providing highly repeatable motion and very little fatigue. Silicon based MEMS devices can have service lifetimes in the range trillions of cycles without failure.
    [Show full text]
  • Microelectromechanical Resonator-Based Components for Wireless Communications
    ESPOO 2006 VTT PUBLICATIONS 616 VTT PUBLICATIONS 616 PUBLICATIONS VTT Communications Wireless for Components Resonator­Based Microelectromechanical Starting in the early 1960's, when the integrated­circuit (IC) technology was developed, micromachining and microelectromechanical systems (MEMS) have grown into a broad research field with several commercial successes. Typical applications of MEMS are in physical, chemical and biochemical sensors, as well as in optical systems such as the digital micromirror device of Texas Instruments. From the 1990's, the advances in the processing technologies and the tremendous growth of the wireless­communication market have drawn much interest into radio­frequency MEMS devices (RF MEMS) such as filters, oscillators, switches and tunable capacitors. This thesis considers electrostatically­actuated RF­MEMS filters and delay lines. The intermodulation properties of capacitively­coupled MEMS filters are analytically solved in closed form and the theory is verified in numerical simulations as well as in measurements with MEMS resonators. The theory is utilized to formulate a design procedure for MEMS filters that takes systems specifications for tolerable intermodulation distortion and insertion­loss into account. For delay lines, capacitive actuation of bulk­ acoustic waves in a solid rod is analyzed. In particular, challenges in impedance matching due to the weakness of the electrostatic coupling are quantified. Finally, a new kind of resonator­chain delay line is introduced. This delay line is characterized by record•low acoustic signal velocity, narrow­band response, and much lower characteristic impedance than Ari Alastalo found for the solid•rod waveguide enabling efficient signal coupling. Microelectromechanical Resonator­ Based Components for Wireless Communications Filters and Transmission Lines Tätä julkaisua myy Denna publikation säljs av This publication is available from VTT VTT VTT PL 1000 PB 1000 P.O.
    [Show full text]