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Book AlGaN GaN HEMTs Reliability Degradation Modes and Analysis

Download or read book AlGaN GaN HEMTs Reliability Degradation Modes and Analysis written by Ponky Ivo and published by Cuvillier. This book was released on 2012-10-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: AlGaN/GaN HEMTs reliability and stability issues were investigated in dependence on epitaxial design and process modification. DC-Step-Stress-Tests have been performed on wafers as a fast device robustness screening method. As a criterion of robustness they deliver a critical source-drain voltage for the onset of degradation. Several degradation modes were observed which depend on epi design, epi quality and process technology. Electrical and optical characterizations together with electric field simulations were performed to get insight into respective degradation modes. It has been found that AlGaN/GaN HEMT devices with GaN cap show higher critical source-drain voltages as compared to non-capped devices. Devices with low Al concentration in the AlGaN barrier layer also show higher critical source-drain voltages. Superior stability and robustness performance have been achieved from devices with AlGaN backbarrier epi design grown on n-type SiC substrate. For the onset on any degradation modes the presence of high electrical fields is most decisive for ON- and OFF-state operation conditions. Therefore careful epi design to reduce high electric field is mandatory. It is also shown that epi buffer quality and growth process have a great impact on device robustness. Defects such as point defects and dislocations are assumed to be created initially during stressing and accumulated to larger defect clusters during device stressing. Electroluminescence (EL) measurements were performed to detect early degradation. Extended localized defects are resulting as bright spots at OFF-state conditions in conjunction with a gate leakage increase.

Book Reliability Studies of AlGaN GaN HEMTs with High k Dielectrics

Download or read book Reliability Studies of AlGaN GaN HEMTs with High k Dielectrics written by and published by . This book was released on 2015 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Power GaN Devices

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.

Book High frequency AlGaN GaN HEMTs Fabrication and Noise Characterization

Download or read book High frequency AlGaN GaN HEMTs Fabrication and Noise Characterization written by Alexei Vasilievich Vertiatchikh and published by . This book was released on 2004 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Simulation of Short Channel AlGaN GaN HEMTs

Download or read book Simulation of Short Channel AlGaN GaN HEMTs written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing data rates demanded by third generation cellular communication systems and other high frequency applications require the use of power amplifiers operating at frequencies exceeding 1 GHz with output of the order of hundreds to thousands of watts. The area of very high frequency, very high power electronics is currently dominated by vacuum tube based devices as conventional semiconductor devices suffer from relatively low breakdown voltages precluding their operation at very high voltages and high powers. The vacuum tube based devices, however, suffer from the issues of high cost, large size and reliability issues. In recent years AlGaN/GaN HEMTs have demonstrated output power densities as high as 11 W/mm operating at microwave frequencies greater than 10 GHz. The extremely high output power density levels are achieved due to the high breakdown voltages of these wide bandgap devices and due to the large polarization induced charge leading to high output current densities. This work investigates the performance of the AlGaN/GaN HEMT using device modeling. Polarization effects have been incorporated using a highly doped AlGaN spacer layer. This thesis examines the effect of the device structure and doping profile on the AlGaN/GaN HEMT's microwave performance including the unilateral power gain and maximum frequency of oscillation.

Book Trapping Effects in AlGaN GaN HEMTs for High Frequency Applications

Download or read book Trapping Effects in AlGaN GaN HEMTs for High Frequency Applications written by Chieh Kai Yang and published by . This book was released on 2011 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Any defect site existing in the AlGaN/GaN HEMTs can be electrically active during device operation. The activated defect site not only could lead to a degradation in the output characteristics but may introduce additional nonlinearity which seriously downgrades the values of devices for various applications. This motivates us to study the detailed path experimentally and theoretically how an electrically-activated defect site could impact the device performances during practical device operation. In this study, the g oal is (1) to give device engineers ideas on how further improvements can be devised to strengthen the existing GaN technology and (2) to provide circuit designers with better understanding on how to use GaN devices more efficiently for the development of reliable commercial GaN products for higher power applications in wireless systems. Single tone characterization results of AlGaN/GaN HEMTs for Class A operation are presented and compared. A new combined large signal network analyzer / deep level optical spectroscopy system is utilized to study the impact of illumination on the CW large-signal load line and small-signal S-parameters variations to identify the possible energy level of the trapping center responsible for the degradation of the device performance. A new pulsed-IV pulsed-RF "coldFET" technique is introduced to extract parasitic elements existing in the access regions of AlGaN/GaN HEMTs. The observation of bias-dependence is detailed and a simple semi-physical model is proposed which provides a satisfactory description of experimental results. The low-frequency noise, an important figure of merit in terms of reliability, is briefly-reviewed. Additive phase noise measurements are presented and the effects of illumination and load impedance are examined. A physical expression is derived and simulated which successfully establishes a relationship between the access resistance and the low-frequency noise and provides a qualitative description of the measurement results.

Book Wide Bandgap Based Devices

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

Book Investigation of Electrical Bias Mechanical Stress Temperature and Ambient Effect on AlGaN GaN Hemt Time Dependent Degradation

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.

Book Thermal Stability and Degradation Analysis of GaN AlGaN Heterostructure

Download or read book Thermal Stability and Degradation Analysis of GaN AlGaN Heterostructure written by Teng Zhang and published by . This book was released on 2018 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: AlGaN/GaN heterostructure is one of the most important materials in applications like High Electron Mobility Transistors (HEMT) and other high speed high power devices. Harsh environment is often encountered for these devices so the thermal stability of the AlGaN/GaN heterostructure is essential. Despite large efforts spent in the last decades, the reliability of GaN HEMT and GaN related devices still represent an issue. The role of high temperature in the degradation of AlGaN/GaN heterostructure is controversial and multiple process occur simultaneously upon thermal activation. This work presents a study of thermal stability of AlGaN/GaN heterostructure in various temperature and different atmosphere. X-ray diffraction and Raman spectroscopy were utilized to characterize the structure degradation. For N2 atmosphere annealing, crystal structure can be maintained up to 1000 C, with better crystallinity due to recrystallization. The FWHM drop for N2 annealed sample is up to 38.9%. Significant degradation is observed when annealed in air: (i) irreversible lattice relaxation; (ii) oxidation and defect propagation; (iii) phase separation of AlGaN. Starting from 750 C, no crystal structure of AlGaN can be detected. Possible failure mechanism is discussed, and these results may be instructive for future device fabrication and optimization.

Book Large Signal Modeling of AlGaN GaN HEMTs for RF and High Power Applications

Download or read book Large Signal Modeling of AlGaN GaN HEMTs for RF and High Power Applications written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Advanced High Speed Devices

Download or read book Advanced High Speed Devices written by Michael S. Shur and published by World Scientific. This book was released on 2010 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced High Speed Devices covers five areas of advanced device technology: terahertz and high speed electronics, ultraviolet emitters and detectors, advanced III-V field effect transistors, III-N materials and devices, and SiC devices. These emerging areas have attracted a lot of attention and the up-to-date results presented in the book will be of interest to most device and electronics engineers and scientists. The contributors range from prominent academics, such as Professor Lester Eastman, to key US Government scientists, such as Dr Michael Wraback. Sample Chapter(s). Chapter 1: Simulation and Experimental Results on Gan Based Ultra-Short Planar Negative Differential Conductivity Diodes for THZ Power Generation (563 KB). Contents: Simulation and Experimental Results on GaN Basee Ultra-Short Planar Negative Differential Conductivity Diodes for THz Power Generation (B Aslan et al.); Millimeter Wave to Terahertz in CMOS (K K O S Sankaran et al.); Surface Acoustic Wave Propagation in GaN-On-Sapphire Under Pulsed Sub-Band Ultraviolet Illumination (V S Chivukula et al.); The First 70nm 6-Inch GaAs PHEMT MMIC Process (H Karimy et al.); Performance of MOSFETs on Reactive-Ion-Etched GaN Surfaces (K Tang et al.); GaN Transistors for Power Switching and Millimeter-Wave Applications (T Ueda et al.); Bi-Directional Scalable Solid-State Circuit Breakers for Hybrid-Electric Vehicles (D P Urciuoli & V Veliadis); and other papers. Readership: Electronic engineers, solid state physicists, graduate students studying physics or electrical engineering.

Book AlGaN GaN HEMT power amplifiers with optimized power added efficiency for X band applications

Download or read book AlGaN GaN HEMT power amplifiers with optimized power added efficiency for X band applications written by Jutta Kühn and published by KIT Scientific Publishing. This book was released on 2011 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has arisen out of the strong demand for a superior power-added efficiency (PAE) of AlGaN/GaN high electron mobility transistor (HEMT) high-power amplifiers (HPAs) that are part of any advanced wireless multifunctional RF-system with limited prime energy. Different concepts and approaches on device and design level for PAE improvements are analyzed, e.g. structural and layout changes of the GaN transistor and advanced circuit design techniques for PAE improvements of GaN HEMT HPAs.

Book Large Signal Properties of AlGaN GaN HEMTs on High Resistivity Silicon Substrates Grown by MBE

Download or read book Large Signal Properties of AlGaN GaN HEMTs on High Resistivity Silicon Substrates Grown by MBE written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The large signal characteristics of 1 Pm long S-gate AlGaN/GaN HEMTs on resistive silicon substrates have been measured and analyzed. The HEMTs demonstrated maximum transconductance and current density values of 350 mS/mm and 1,200 mA/mm respectively. High current gain and maximum power gain frequencies ft and fmax were measured at 25 GHz and 43 GHz .Large signal gain and power density values of 16 dBand 1.7 W/mm for a two-finger 1x75 Pm 2 HEMT respectively were observed at 5 GHz. The device also exhibited PAE values as high as 40%with P1dB around +2.0 dBm for Class AB operation.