Download or read book Investigation of Lattice and Thermal Stress in GaN AlGaN Field Effect Transistors written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes work performed in support of the program "Investigation of Lattice and Thermal Stress in GaN/AlGaN Field-Effect Transistors" (Contract No N00014-05-C-0120) for the period 10/1/06 - 4/30/07. Our overall goal is to understand the role and contribution of residual stress and junction temperature on the degradation of AlGaN/GaN HEMT electrical device characteristics To execute this goal, electrical stress measurements will be performed on devices with varying residual stress, and under varying conditions We plan to use the micro-kaman technique to monitor the evolution of residual stress in the active region of the device over time and under quiescent electrical bias The question of whether a stress relaxation, potentially inducing dislocations, or simply changing the piezoelectric contribution to the 2DEG charge, contributes to device degradation will be investigated We will seek to understand the influence of junction temperature on the magnitude of the stress at the active junction. The effect of physical, thermal, and electrical stress on device reliability will be investigated.

Download or read book Investigation of Lattice and Thermal Stress in GaN A1GaN Field Effect Transistors written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes work performed in support of the program Investigation of Lattice and Thermal Stress in GaN/AlGaN Field-Effect Transistors (Contract No. N00014-05- C-0120) for the period 7/1/06 - 9/30/06. Our overall goal is to understand the role and contribution of residual stress and junction temperature on the degradation of AlGaN/GaN HEMT electrical device characteristics. To execute this goal, electrical stress measurements will be performed on devices with varying residual stress, and under varying conditions. We plan to use the micro-Raman technique to monitor the evolution of residual stress in the active region of the device over time and under quiescent electrical bias. The question of whether a stress relaxation, potentially inducing dislocations, or simply changing the piezoelectric contribution to the 2DEG charge, contributes to device degradation will be investigated. We will seek to understand the influence of junction temperature on the magnitude of the stress at the active junction. The effect of physical, thermal, and electrical stress on device reliability will be investigated.

Download or read book Gan based Materials And Devices Growth Fabrication Characterization And Performance written by Robert F Davis and published by World Scientific. This book was released on 2004-05-07 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unique materials properties of GaN-based semiconductors have stimulated a great deal of interest in research and development regarding nitride materials growth and optoelectronic and nitride-based electronic devices. High electron mobility and saturation velocity, high sheet carrier concentration at heterojunction interfaces, high breakdown field, and low thermal impedance of GaN-based films grown over SiC or bulk AlN substrates make nitride-based electronic devices very promising. The chemical inertness of nitrides is another key property.This volume, written by experts on different aspects of nitride technology, addresses the entire spectrum of issues related to nitride materials and devices, and it will be useful for technologists, scientists, engineers, and graduate students who are working on wide bandgap materials and devices. The book can also be used as a supplementary text for graduate courses on wide bandgap semiconductor technology.

Download or read book Thermal Analysis of AlGaN GaN Heterostructure Field Effect Transistors Using Nematic Liquid Crystals and In house Codes written by Dimitri Kakovitch and published by . This book was released on 2003 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Electrical Bias Mechanical Stress Temperature and Ambient Effect on AlGaN GaN Hemt Time Dependent Degradation written by Amit Gupta and published by . This book was released on 2013 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: AlGaN/GaN HEMT technology is promising for RF and high power applications. However commercial usability of this technology is currently hindered because of its limited electrical reliability which still remains a major concern. AlGaN/GaN HEMTs have been shown to degrade irreversibly under typical device operation and there is widespread disagreement on the underlying fundamental physics for the observed device degradation. Electrical degradation in AlGaN/GaN HEMTs due to DC stressing is studied typically by performing electrical step stress tests and a critical voltage is determined. Device degradation is characterized by changes measured in electrical parameters, such as increase in Rs and RD, decrease in IDsat, decrease in gm, Vt shift and sub-threshold change. The widely accepted theory attributes such degradation to the inverse piezoelectric effect. Electric field due to applied bias generates biaxial tensile stress which together with intrinsic stress from lattice mismatch increases the elastic energy of AlGaN layer.

Download or read book Ambient Temperature Effects on the Performance of A1GaN GaN Heterostructure Field effect Transistors written by Yang-An Tan and published by . This book was released on 2007 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book DC Microwave and Noise Properties of Gan Based Heterojunction Field Effect Transistors and Their Reliability Issues written by Congyong Zhu and published by . This book was released on 2013 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: AlGaN/GaN and InAlN/GaN-based heterojunction field effect transistors (HFETs) have demonstrated great high power and high frequency performance. Although AlGaN/GaN HFETs are commercially available, there still remain issues regarding long-term reliability, particularly degradation and ultimately device failure due to the gate-drain region where the electric field peaks. One of the proposed degradation mechanisms is the inverse-piezoelectric effect that results from the vertical electric field and increases the tensile strain. Other proposed mechanisms include hot-electron-induced trap generation, impurity diffusion, surface oxidation, and hot-electron/phonon effects. To investigate the degradation mechanism and its impact on DC, microwave, and noise performance, comprehensive stress experiments were conducted in both un-passivated and passivated AlGaN/GaN HFETs. It was found that degradation of AlGaN/GaN HFETs under reverse-gate-bias stress is dominated by inverse-piezoelectric effect and/or hot-electron injection due to gate leakage. Degradation under on-state-high-field stress is dominated by hot-electron/phonon effects, especially at high drain bias. Both effects are induced by the high electric field present during stress, where the inverse-piezoelectric effect only relates to the vertical electric field and the hot-electron effect relates to the total electric field. InAlN/GaN-based HFETs are expected to have even better performance as power amplifiers due to the large 2DEG density at the InAlN/GaN interface and better lattice-matching. Electrical stress experiments were therefore conducted on InAlN/GaN HFETs with indium compositions ranging from 15.7% to 20.0%. Devices with indium composition of 18.5% were found to give the best compromise between reliability and device performance. For indium compositions of 15.7% and 17.5%, the HFET devices degraded very fast (25 h) under on-state-high-field stress, while the HFET devices with 20.0% indium composition showed very small drain. It was also demonstrated that hot-electron/phonon effects are the major degradation mechanism for InAlN/GaN HFETs due to a large 2DEG density under on-state operations, whereas the inverse-piezoelectric effect is very small due to the small strain for the near lattice-matched InAlN barrier. Compared to lattice-matched InAlN/GaN HFETs, AlGaN/GaN HFETs have much larger strain in the barrier and about half of the drain current level; however, the hot electron/hot phonon effects are still important, especially at high drain bias.

Download or read book Power GaN Devices written by Matteo Meneghini and published by Springer. This book was released on 2016-09-08 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the first comprehensive overview of the properties and fabrication methods of GaN-based power transistors, with contributions from the most active research groups in the field. It describes how gallium nitride has emerged as an excellent material for the fabrication of power transistors; thanks to the high energy gap, high breakdown field, and saturation velocity of GaN, these devices can reach breakdown voltages beyond the kV range, and very high switching frequencies, thus being suitable for application in power conversion systems. Based on GaN, switching-mode power converters with efficiency in excess of 99 % have been already demonstrated, thus clearing the way for massive adoption of GaN transistors in the power conversion market. This is expected to have important advantages at both the environmental and economic level, since power conversion losses account for 10 % of global electricity consumption. The first part of the book describes the properties and advantages of gallium nitride compared to conventional semiconductor materials. The second part of the book describes the techniques used for device fabrication, and the methods for GaN-on-Silicon mass production. Specific attention is paid to the three most advanced device structures: lateral transistors, vertical power devices, and nanowire-based HEMTs. Other relevant topics covered by the book are the strategies for normally-off operation, and the problems related to device reliability. The last chapter reviews the switching characteristics of GaN HEMTs based on a systems level approach. This book is a unique reference for people working in the materials, device and power electronics fields; it provides interdisciplinary information on material growth, device fabrication, reliability issues and circuit-level switching investigation.

Download or read book Analysis and Optimization of AlGaN GaN High Electron Mobility Transistors for Microwave Applications written by Michael Hosch and published by Cuvillier Verlag. This book was released on 2011-08-08 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis deals with the analysis and optimization of some of the most prominent non-ideal effects in AlGaN/GaN high electron mobility transistors used in microwave applications as well as the optimization of the RF gain. The effect of current collapse, the root cause of leakage currents as well as field-dependent self-heating effects have been investigated by eletrical characterization using well established techniques and have been analyzed using 2-dimensional physical device simulations. It will be shown that the origin of all effects is strongly related to the device surface and some are even competing effects making device optimization a challenge. However, a detailed localization of the regions affecting device performance will be given leading to a better understanding for fabrication process optimization. Finally, I simulation study is conducted giving suggestions for RF gain improvement based on very simple device layout variations.

Download or read book Thermal Management of Gallium Nitride Electronics written by Marko Tadjer and published by Woodhead Publishing. This book was released on 2022-07-13 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal Management of Gallium Nitride Electronics outlines the technical approaches undertaken by leaders in the community, the challenges they have faced, and the resulting advances in the field. This book serves as a one-stop reference for compound semiconductor device researchers tasked with solving this engineering challenge for future material systems based on ultra-wide bandgap semiconductors. A number of perspectives are included, such as the growth methods of nanocrystalline diamond, the materials integration of polycrystalline diamond through wafer bonding, and the new physics of thermal transport across heterogeneous interfaces. Over the past 10 years, the book's authors have performed pioneering experiments in the integration of nanocrystalline diamond capping layers into the fabrication process of compound semiconductor devices. Significant research efforts of integrating diamond and GaN have been reported by a number of groups since then, thus resulting in active thermal management options that do not necessarily lead to performance derating to avoid self-heating during radio frequency or power switching operation of these devices. Self-heating refers to the increased channel temperature caused by increased energy transfer from electrons to the lattice at high power. This book chronicles those breakthroughs. Includes the fundamentals of thermal management of wide-bandgap semiconductors, with historical context, a review of common heating issues, thermal transport physics, and characterization methods Reviews the latest strategies to overcome heating issues through materials modeling, growth and device design strategies Touches on emerging, real-world applications for thermal management strategies in power electronics

Download or read book An Experimental Study of AlGaN GaN Heterostructure Field effect Transistors HFETs written by Wei San Tan and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fabrication and Investigation of AlGaN GaN Metal oxide semiconductor High electron Mobility Field effect Transistors with Gate Insulators Grown Using PEC Oxidation Method written by 黃立賢 and published by . This book was released on 2009 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book GaN Transistors for Efficient Power Conversion written by Alex Lidow and published by John Wiley & Sons. This book was released on 2019-08-12 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: An up-to-date, practical guide on upgrading from silicon to GaN, and how to use GaN transistors in power conversion systems design This updated, third edition of a popular book on GaN transistors for efficient power conversion has been substantially expanded to keep students and practicing power conversion engineers ahead of the learning curve in GaN technology advancements. Acknowledging that GaN transistors are not one-to-one replacements for the current MOSFET technology, this book serves as a practical guide for understanding basic GaN transistor construction, characteristics, and applications. Included are discussions on the fundamental physics of these power semiconductors, layout, and other circuit design considerations, as well as specific application examples demonstrating design techniques when employing GaN devices. GaN Transistors for Efficient Power Conversion, 3rd Edition brings key updates to the chapters of Driving GaN Transistors; Modeling, Simulation, and Measurement of GaN Transistors; DC-DC Power Conversion; Envelope Tracking; and Highly Resonant Wireless Energy Transfer. It also offers new chapters on Thermal Management, Multilevel Converters, and Lidar, and revises many others throughout. Written by leaders in the power semiconductor field and industry pioneers in GaN power transistor technology and applications Updated with 35% new material, including three new chapters on Thermal Management, Multilevel Converters, Wireless Power, and Lidar Features practical guidance on formulating specific circuit designs when constructing power conversion systems using GaN transistors A valuable resource for professional engineers, systems designers, and electrical engineering students who need to fully understand the state-of-the-art GaN Transistors for Efficient Power Conversion, 3rd Edition is an essential learning tool and reference guide that enables power conversion engineers to design energy-efficient, smaller, and more cost-effective products using GaN transistors.

Download or read book Intricacies of Modeling and Analysis of DC Characteristics of Single and Multi Channel Laterally Gated AlGaN GaN Heterojunction Field Effect Transistors written by Mauricio Buitrago and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present thesis offers a detailed description about the modeling of single- and multi-channel laterally-gated AlGaN/GaN heterojunction field effect transistors (HFETs) through device investigation in the Comsol Multiphysics® simulation environment. After two decades of research, studying GaN HFETs continues to be a very interesting area of investigation. This is because of the interest in using these devices in high frequency applications as well as low frequency power management. Laterally-gated GaN HFETs have recently drawn the attention of semiconductor devices engineers that search for obtaining higher current densities, higher linearity, better stability at higher frequencies, and better power management while increasing packing density. The presented simulations offer an in-depth analysis of the observations made at thermal equilibrium and the results obtained for the DC characteristics of these devices, along with the comparison of these characteristics with those of the top-gated varieties. These observations demonstrate the improved effectiveness of lateral gating in controlling multiple vertically stacked 2DEG channels. Although there is improvement on several parameters like current density, linearity, and ON resistance (Ron), as the number of channels increases, simulations demonstrate a certain degree of degradation of drain-induced barrier lowering (DIBL) and knee voltage (Vknee). For these simulations, the devices' self-heating at higher current densities was not considered. Also, the ohmic contacts were assumed to be ideal.

Download or read book Wide Bandgap Based Devices written by Farid Medjdoub and published by MDPI. This book was released on 2021-05-26 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging wide bandgap (WBG) semiconductors hold the potential to advance the global industry in the same way that, more than 50 years ago, the invention of the silicon (Si) chip enabled the modern computer era. SiC- and GaN-based devices are starting to become more commercially available. Smaller, faster, and more efficient than their counterpart Si-based components, these WBG devices also offer greater expected reliability in tougher operating conditions. Furthermore, in this frame, a new class of microelectronic-grade semiconducting materials that have an even larger bandgap than the previously established wide bandgap semiconductors, such as GaN and SiC, have been created, and are thus referred to as “ultra-wide bandgap” materials. These materials, which include AlGaN, AlN, diamond, Ga2O3, and BN, offer theoretically superior properties, including a higher critical breakdown field, higher temperature operation, and potentially higher radiation tolerance. These attributes, in turn, make it possible to use revolutionary new devices for extreme environments, such as high-efficiency power transistors, because of the improved Baliga figure of merit, ultra-high voltage pulsed power switches, high-efficiency UV-LEDs, and electronics. This Special Issue aims to collect high quality research papers, short communications, and review articles that focus on wide bandgap device design, fabrication, and advanced characterization. The Special Issue will also publish selected papers from the 43rd Workshop on Compound Semiconductor Devices and Integrated Circuits, held in France (WOCSDICE 2019), which brings together scientists and engineers working in the area of III–V, and other compound semiconductor devices and integrated circuits. In particular, the following topics are addressed: – GaN- and SiC-based devices for power and optoelectronic applications – Ga2O3 substrate development, and Ga2O3 thin film growth, doping, and devices – AlN-based emerging material and devices – BN epitaxial growth, characterization, and devices

Download or read book Analytic Modeling of Tunnel Field Effect Transistors and Experimental Investigation of GaN High Electron Mobility Transistors written by Jianzhi Wu and published by . This book was released on 2016 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: High density and lower power drive the aggressive scaling down of CMOS transistors. Yet, the scaling of Si bulk MOSFETs are approaching physical limits, suffering from poor electrostatic control due to short channel effects, gate leakage current caused by gate oxide tunneling, and most importantly the non-scaled supply voltage imposed by thermionic emission limitation. Tunnel FETs (TFETs) based on band-to-band tunneling current injection mechanism, have emerged as promising candidates to deliver steep turn-off slopes, thus enables a sharp reduction of supply voltage to below 0.5 V. This dissertation is primarily devoted to develop an accurate analytic model for TFETs with a double-gate structure, providing physical insights to the design principles. At the core of the model is a gate-controlled channel potential that satisfies the source and drain boundary conditions. The potential is of an exponential profile with a characteristic scale length given by the device thickness. Both the source-to-channel tunneling and source-to-drain tunneling are developed and included in the model. It has been verified by numerical simulations for a wide range of bandgaps and channel lengths. Also incorporated in the model are the short-channel effect, source doping effect, ambipolar effect, and de-bias of gate voltage by channel charge. Based on these, the guidelines for scaling TFETs to sub-10-nm channel lengths are brought forth. The model is continuous, physical and predictive in the sense that there is no need for ad hoc fitting parameters. For high-power and high-frequency applications, GaN high-electron-mobility-transistors (HEMTs) stand out as promising candidate devices for achieving high breakdown voltage, high output current and high transconductance characteristics. Yet, the performance of GaN HEMTs suffers from mobility degradation due to poor thermal dissipation of conventional epitaxial substrates. This dissertation also experimentally demonstrates the GaN HEMTs fabricated on diamond substrate with extraordinary thermal management capability. The self-heating induced current droop is effectively absent in the saturated Ids-Vds characteristics of the resulting devices, thus paving the way for enhancing the energy conversion efficiency.

Download or read book Investigation of AlGaN GaN Heterostructure Ion Sensitive Field Effect Transistor for PH Sensor Application written by 陳韋帆 and published by . This book was released on 2014 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: