Download or read book Impact of Electrochemical Process on the Degradation Mechanisms of AlGaN GaN HEMTs written by Feng Gao (Ph. D.) and published by . This book was released on 2014 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: AlGaN/GaN high electron mobility transistors (HEMTs) constitute a new generation of transistors with excellent electrical characteristics and great potential to replace silicon technology in the future, especially in high power and high frequency applications. However, the poor long term reliability of these devices is an important bottleneck for their wide market insertion and limits their advanced development. This thesis tackles this problem by focusing on understanding the physics behind various degradation modes and providing new quantitative models to explain these mechanisms. The first part of the thesis, Chapters 2 and 3, reports studies of the origin of permanent structural and electrical degradation in AlGaN/GaN HEMTs. Hydroxyl groups (OH-) from the environment and/or adsorbed water on the III-N surface are found to play an important role in the formation of surface pits during the OFF-state electrical stress. The mechanism of this water-related structural degradation is explained by an electrochemical cell formed at the gate edge where gate metal, the II-N surface and the passivation layer meet. Moreover, the permanent decrease of the drain current is directly linked with the formation of the surface pits, while the permanent increase of the gate current is found to be uncorrelated with the structural degradation. The second part of the thesis, Chapters 4 and 5, identifies water-related redox couples in ambient air as important sources of dynamic on-resistance and drain current collapse in AlGaN/GaN HEMTs. Through in-situ X-ray photoelectron spectroscopy (XPS), direct signature of the water-related species is found at the AlGaN surface at room temperature. It is also found that these species, as well as the current collapse, can be thermally removed above 200 °C in vacuum conditions. An electron trapping mechanism based on H2O/H2 and H2O/O2 redox couples is proposed to explain the 0.5 eV energy level commonly attributed to surface trapping states. Moreover, the role of silicon nitride passivation in successfully removing current collapse in these devices is explained by blocking the water molecules away from the AlGaN surface. Finally, fluorocarbon, a highly hydrophobic material, is proven to be an excellent passivation to overcome transient degradation mechanisms in AlGaN/GaN HEMTs.
Download or read book AlGaN GaN HEMTs Reliability written by Ponky Ivo and published by Cuvillier Verlag. This book was released on 2012-10-25 with total page 132 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. AlGaN/GaN HEMTs mit unterschiedlichen epitaktischen Designs und Prozessmodifikationen wurden auf ihre Zuverlässigkeit und Stabilität untersucht. DC-Stufenstresstests wurden als Screeningmethode für die Bauelementrobustheit durchgeführt. Mit dieser Methode erhält man eine kritische Source-Drain-Spannung, die den Beginn der Degradation kennzeichnet. Verschiedene Degradationsmodi wurden beobachtet, die vom epitaxialem Design, der epitaxialen Qualität und der Prozesstechnologie abhängen. Elektrische und optische Messungen zusammen mit elektrischen Feldsimulationen wurden durchgeführt, um Einblick in das Degradationsverhalten zu bekommen. Es hat sich gezeigt, dass AlGaN/GaN HEMTs mit einer GaN Cap-Schicht eine höhere kritische Drain-Source-Spannung zeigen als Transistoren ohne diese Schicht. HEMTs mit niedriger Aluminiumkonzentration in der AlGaN-Barriere zeigen ebenfalls eine höhere kritische Drain-Source-Spannung. Transistoren mit AlGaNBackbarrier, die auf n-Typ SiC-Substraten gewachsen wurden, zeigen eine besonders hohe Stabilität und Robustheit. Für den Betrieb im ON-State als auch im OFF-State ist ein hohes elektrisches Feld entscheidend für den Beginn der Degradation. Daher sind epitaxiale Designs, die das elektrische Feld so weit wie möglich reduzieren, von großer Wichtigkeit. Es wird gezeigt, dass die Qualität der Bufferschicht und der Wachstumsprozess der epitaxierten Schichten großen Einfluß auf die Robustheit der Bauelemente haben. Zu Beginn des Stressprozesses werden Punktdefekte und Versetzungen erzeugt, die im weiteren Verlauf des Stresstests zu Agglomeration von Defektclustern führen. Der Beginn der Degradation wurde mit Hilfe der Elektrolumineszenz untersucht. Im OFF-State werden ausgedehnte lokalisierte Defekte als stark leuchtende Flecken detektiert, wobei gleichzeitig ein Anstieg der Leckströme zu beobachten ist.
Download or read book State of the Art Program on Compound Semiconductors 53 SOTAPOCS 53 written by M. E. Overberg and published by The Electrochemical Society. This book was released on 2011 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitride Semiconductor Technology written by Fabrizio Roccaforte and published by John Wiley & Sons. This book was released on 2020-07-30 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book "Nitride Semiconductor Technology" provides an overview of nitride semiconductors and their uses in optoelectronics and power electronics devices. It explains the physical properties of those materials as well as their growth methods. Their applications in high electron mobility transistors, vertical power devices, LEDs, laser diodes, and vertical-cavity surface-emitting lasers are discussed in detail. The book further examines reliability issues in these materials and puts forward perspectives of integrating them with 2D materials for novel high-frequency and high-power devices. In summary, it covers nitride semiconductor technology from materials to devices and provides the basis for further research.
Download or read book Gallium Nitride and Silicon Carbide Power Technologies 4 written by K. Shenai and published by The Electrochemical Society. This book was released on with total page 312 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 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 Gallium Nitride enabled High Frequency and High Efficiency Power Conversion written by Gaudenzio Meneghesso and published by Springer. This book was released on 2018-05-12 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book demonstrates to readers why Gallium Nitride (GaN) transistors have a superior performance as compared to the already mature Silicon technology. The new GaN-based transistors here described enable both high frequency and high efficiency power conversion, leading to smaller and more efficient power systems. Coverage includes i) GaN substrates and device physics; ii) innovative GaN -transistors structure (lateral and vertical); iii) reliability and robustness of GaN-power transistors; iv) impact of parasitic on GaN based power conversion, v) new power converter architectures and vi) GaN in switched mode power conversion. Provides single-source reference to Gallium Nitride (GaN)-based technologies, from the material level to circuit level, both for power conversions architectures and switched mode power amplifiers; Demonstrates how GaN is a superior technology for switching devices, enabling both high frequency, high efficiency and lower cost power conversion; Enables design of smaller, cheaper and more efficient power supplies.
Download or read book Gallium Nitride GaN written by Farid Medjdoub and published by CRC Press. This book was released on 2017-12-19 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addresses a Growing Need for High-Power and High-Frequency Transistors Gallium Nitride (GaN): Physics, Devices, and Technology offers a balanced perspective on the state of the art in gallium nitride technology. A semiconductor commonly used in bright light-emitting diodes, GaN can serve as a great alternative to existing devices used in microelectronics. It has a wide band gap and high electron mobility that gives it special properties for applications in optoelectronic, high-power, and high-frequency devices, and because of its high off-state breakdown strength combined with excellent on-state channel conductivity, GaN is an ideal candidate for switching power transistors. Explores Recent Progress in High-Frequency GaN Technology Written by a panel of academic and industry experts from around the globe, this book reviews the advantages of GaN-based material systems suitable for high-frequency, high-power applications. It provides an overview of the semiconductor environment, outlines the fundamental device physics of GaN, and describes GaN materials and device structures that are needed for the next stage of microelectronics and optoelectronics. The book details the development of radio frequency (RF) semiconductor devices and circuits, considers the current challenges that the industry now faces, and examines future trends. In addition, the authors: Propose a design in which multiple LED stacks can be connected in a series using interband tunnel junction (TJ) interconnects Examine GaN technology while in its early stages of high-volume deployment in commercial and military products Consider the potential use of both sunlight and hydrogen as promising and prominent energy sources for this technology Introduce two unique methods, PEC oxidation and vapor cooling condensation methods, for the deposition of high-quality oxide layers A single-source reference for students and professionals, Gallium Nitride (GaN): Physics, Devices, and Technology provides an overall assessment of the semiconductor environment, discusses the potential use of GaN-based technology for RF semiconductor devices, and highlights the current and emerging applications of GaN.
Download or read book State of the Art Program on Compound Semiconductors XLI and Nitride and Wide Bandgap Semiconductors for Sensors Photonics and Electronics V written by H. M. Ng and published by The Electrochemical Society. This book was released on 2004 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silicon Compatible Materials Processes and Technologies for Advanced Integrated Circuits and Emerging Applications 6 written by Fred Roozeboom and published by The Electrochemical Society. This book was released on with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gallium Nitride Electronics written by Rüdiger Quay and published by Springer Science & Business Media. This book was released on 2008-04-05 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on nearly a decade of materials and electronics research at the leading research institution on the nitride topic in Europe. It is a comprehensive monograph and tutorial that will be of interest to graduate students of electrical engineering, communication engineering, and physics; to materials, device, and circuit engineers in research and industry; to all scientists with a general interest in advanced electronics.
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 The Physics of Semiconductor Devices written by R. K. Sharma and published by Springer. This book was released on 2019-01-31 with total page 1299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book disseminates the current knowledge of semiconductor physics and its applications across the scientific community. It is based on a biennial workshop that provides the participating research groups with a stimulating platform for interaction and collaboration with colleagues from the same scientific community. The book discusses the latest developments in the field of III-nitrides; materials & devices, compound semiconductors, VLSI technology, optoelectronics, sensors, photovoltaics, crystal growth, epitaxy and characterization, graphene and other 2D materials and organic semiconductors.
Download or read book Fabrication of GaAs Devices written by Albert G. Baca and published by IET. This book was released on 2005-09 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides fundamental and practical information on all aspects of GaAs processing and gives pragmatic advice on cleaning and passivation, wet and dry etching and photolithography. Other topics covered include device performance for HBTs (Heterojunction Bipolar Transistors) and FETs (Field Effect Transistors), how these relate to processing choices, and special processing issues such as wet oxidation, which are especially important in optoelectronic devices. This book is suitable for both new and practising engineers.
Download or read book Polarization Effects in Semiconductors written by Debdeep Jena and published by Springer Science & Business Media. This book was released on 2008 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polarization Effects in Semiconductors: From Ab Initio Theory to Device Applications presents the latest understanding of the solid state physics, electronic implications and practical applications of the unique spontaneous or pyro-electric polarization charge of wurtzite compound semiconductors, and associated piezo-electric effects in strained thin film heterostructures. These heterostructures are used in wide band gap semiconductor based sensors, in addition to various electronic and opto-electronic semiconductor devices. The book covers the ab initio theory of polarization in cubic and hexagonal semiconductors, growth of thin film GaN, GaN/AlGaN GaAlN/ AlGaInN, and other nitrides, and SiC heterostructures. It discusses the effects of spontaneous and piezoelectric polarization on band diagrams and electronic properties of abrupt and compositionally graded heterostructures, electronic characterization of polarization-induced charge distributions by scanning-probe spectroscopies, and gauge factors and strain effects. In addition, polarization in extended defects, piezo-electric strain/charge engineering, and application to device design and processing are covered. The effects of polarization on the fundamental electron transport properties, and on the basic optical transitions are described. The crucial role of polarization in devices such as high electron mobility transistors (HEMTs) and light-emitting diodes (LEDs) is covered. The chapters are authored by professors and researchers in the fields of physics, applied physics and electrical engineering, who worked for 5 years under the "Polarization Effects in Semiconductors" DOD funded Multi Disciplinary University Research Initiative. This book will be of interest to graduate students and researchers working in the field of wide-bandgap semiconductor physics and their device applications. It will also be useful for practicing engineers in the field of wide-bandgap semiconductor device research and development.
Download or read book GaN and Related Materials written by Stephen J. Pearton and published by CRC Press. This book was released on 2021-10-08 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents views on current developments in heat and mass transfer research related to the modern development of heat exchangers. Devotes special attention to the different modes of heat and mass transfer mechanisms in relation to the new development of heat exchangers design. Dedicates particular attention to the future needs and demands for further development in heat and mass transfer. GaN and related materials are attracting tremendous interest for their applications to high-density optical data storage, blue/green diode lasers and LEDs, high-temperature electronics for high-power microwave applications, electronics for aerospace and automobiles, and stable passivation films for semiconductors. In addition, there is great scientific interest in the nitrides, because they appear to form the first semiconductor system in which extended defects do not severely affect the optical properties of devices. This series provides a forum for the latest research in this rapidly-changing field, offering readers a basic understanding of new developments in recent research. Series volumes feature a balance between original theoretical and experimental research in basic physics, device physics, novel materials and quantum structures, processing, and systems.
