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.

Download or read book Semiconductor Wafer Bonding VIII Science Technology and Applications written by and published by The Electrochemical Society. This book was released on 2005 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Large signal Modeling of GaN HEMTs for Linear Power Amplifier Design written by Endalkachew Shewarega Mengistu and published by kassel university press GmbH. This book was released on 2008 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Large Signal Modeling of GaN Device for High Power Amplifier Design written by Anwar Hasan Jarndal and published by kassel university press GmbH. This book was released on 2006 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AlGaN GaN HEMTs on Semi Insulating GaN Substrates by MOCVD and MBE written by and published by . This book was released on 2007 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon (Si) implantation into AIGaN/GaN high electron mobility transistors (HEMTs) has been studied in this program as a method to reduce the sharp increase in the dynamic source resistance at increasing current levels that result in a reduction both in the transconductance gm and the current gain cut-off frequency fT. During the program two different approaches have been investigated to decrease the electric field in the source access region. To prevent breakdown between source and gate, different barrier layers have been investigated. Ultimately, these barriers allow an overlap between the gate and the source implant region. First, a regrown AIGaN/GaN channel as the barrier between the source implant region and the gate has been investigated. In the past, silicon has been found to create a buried parasitic layer conductive path at the re-grown interface. In this work, multiple-cycle treatment with hydrofluoric acid and ozone was used to reduce the silicon at the regrowth interface by 80%. Second, using silicon nitride (SiN) as the barrier layer between the implanted source region and the gate allowed a regrowth free structure. MOCVD grown SiN was deposited in situ after the activation anneal of the implanted silicon. With channels lengths down to 0.3 jam and gate lengths of 200 nm, these devices exhibited constant dynamic source resistances which improved the transconductance linearity at high current levels significantly.

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 Progress in Microwave GaN HEMT Grown by MBE on Silicon and Smart Cut TM Engineered Substrates for High Power Applications written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: SiCOI (SiC On Insulator) composite substrates obtained by the Smart-Cut TM process are alternative possible substrates for epitaxial growth of Wide Band Gap (WBG) materials such as GaN and GaN alloys. Similar to bonded SOI structure, the SiCOI structures basically comprises a thin film of single SiC crystal bonded onto a substrate such as, for instance, silicon substrate. Additionally to the well known insulation properties, SiCOI substrates have been proven to be adapted to the growth of high quality GaN layer. This first study has proven compatibility of SiCOI structure for single layer GaN MBE growth. We present here last results of AlGaN / GaN HEMT structure grown by MBE with NH3 as nitrogen precursor onto SiCOI (on silicon) structure realised by Smart Cut TM. First of all, complete SiCOI structure realisation will be described and typical physical characterization results will be presented for this kind of substrate. Then, will be detailed MBE epitaxy set-up and growth parameters for HEMT structure, including specific buffer layer stack description. Finally, physical and electrical characterisation results for epi-layers and HEMT structure will be presented. Those results show strong compatibility of SiCOI structure for MBE epitaxy of GaN based HEMT structure and demonstrate the interest of Smart Cut TM approach to build composite substrates, like SiCOI, for hetero-epitaxy application.

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 GaN Based HEMTs for High Voltage Operation Design Technology and Characterization written by Eldad Bahat-Treidel and published by Cuvillier Verlag. This book was released on 2012-06-08 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gallium nitride (GaN)-based High Electron Mobility Transistors (HEMTs) for high voltage, high power switching and regulating for space applications are studied in this work. Efficient power switching is associated with operation in high OFF-state blocking voltage while keeping the ON-state resistance, the dynamic dispersion and leakage currents as low as possible. The potential of such devices to operate at high voltages is limited by a chain of factors such as subthreshold leakages and the device geometry. Blocking voltage enhancement is a complicated problem that requires parallel methods for solution; epitaxial layers design, device structural and geometry design, and suitable semiconductor manufacturing technique. In this work physical-based device simulation as an engineering tool was developed. An overview on GaN-based HEMTs physical based device simulation using Silvaco-“ATLAS” is given. The simulation is utilized to analyze, give insight to the modes of operation of the device and for design and evaluation of innovative concepts. Physical-based models that describe the properties of the semiconductor material are introduced. A detailed description of the specific AlGaN/GaN HEMT structure definition and geometries are given along with the complex fine meshing requirements. Nitride-semiconductor specific material properties and their physical models are reviewed focusing on the energetic band structure, epitaxial strain tensor calculation in wurtzite materials and build-in polarization models. Special attention for thermal conductivity, carriers’ mobility and Schottky-gate-reverse-bias-tunneling is paid. Empirical parameters matching and adjustment of models parameters to match the experimental device measured results are discussed. An enhancement of breakdown voltage in AlxGa1-xN/GaN HEMT devices by increasing the electron confinement in the transistor channel using a low Al content AlyGa1-yN back-barrier layer structure is systematically studied. It is shown that the reduced sub-threshold drain-leakage current through the buffer layer postpones the punch-through and therefore shifts the breakdown of the device to higher voltages. It is also shown that the punch-through voltage (VPT) scales up with the device dimensions (gate to drain separation). An optimized electron confinement results both, in a scaling of breakdown voltage with device geometry and a significantly reduced sub-threshold drain and gate leakage currents. These beneficial properties are pronounced even further if gate recess technology is applied for device fabrication. For the systematic study a large variations of back-barrier epitaxial structures were grown on sapphire, n-type 4H-SiC and semi-insulating 4H-SiC substrates. The devices with 5 μm gate-drain separation grown on n-SiC owning Al0.05Ga0.95N and Al0.10Ga0.90N back-barrier exhibit 304 V and 0.43 m × cm2 and 342 V and 0.41 m × cm2 respectively. To investigate the impact of AlyGa1-yN back-barrier on the device properties the devices were characterized in DC along with microwave mode and robustness DC-step-stress test. Physical-based device simulations give insight in the respective electronic mechanisms and to the punch-through process that leads to device breakdown. Systematic study of GaN-based HEMT devices with insulating carbon-doped GaN back-barrier for high voltage operation is also presented. Suppression of the OFF-state sub-threshold drain leakage-currents enables breakdown voltage enhancement over 1000 V with low ON-state resistance. The devices with 5 μm gate-drain separation on SI-SiC and 7 μm gate-drain separation on n-SiC exhibit 938 V and 0.39 m × cm2 and 942 V and 0.39 m × cm2 respectively. Power device figure of merit of ~2.3 × 109 V2/-cm2 was calculated for these devices. The impacts of variations of carbon doping concentration, GaN channel thickness and substrates are evaluated. Trade-off considerations in ON-state resistance and of current collapse are addressed. A novel GaN-based HEMTs with innovative planar Multiple-Grating-Field-Plates (MGFPs) for high voltage operation are described. A synergy effect with additional electron channel confinement by using a heterojunction AlGaN back-barrier is demonstrated. Suppression of the OFF-state sub-threshold gate and drain leakage-currents enables breakdown voltage enhancement over 700 V and low ON-state resistance of 0.68 m × cm2. Such devices have a minor trade-off in ON-state resistance, lag factor, maximum oscillation frequency and cut-off frequency. Systematic study of the MGFP design and the effect of Al composition in the back-barrier are described. Physics-based device simulation results give insight into electric field distribution and charge carrier concentration depending on field-plate design. The GaN superior material breakdown strength properties are not always a guarantee for high voltage devices. In addition to superior epitaxial growth design and optimization for high voltage operation the device geometrical layout design and the device manufacturing process design and parameters optimization are important criteria for breakdown voltage enhancement. Smart layout prevent immature breakdown due to lateral proximity of highly biased interconnects. Optimization of inter device isolation designed for high voltage prevents substantial subthreshold leakage. An example for high voltage test device layout design and an example for critical inter-device insulation manufacturing process optimization are presented. While major efforts are being made to improve the forward blocking performance, devices with reverse blocking capability are also desired in a number of applications. A novel GaN-based HEMT with reverse blocking capability for Class-S switch-mode amplifiers is introduced. The high voltage protection is achieved by introducing an integrated recessed Schottky contact as a drain electrode. Results from our Schottky-drain HEMT demonstrate an excellent reverse blocking with minor trade-off in the ON-state resistance for the complete device. The excellent quality of the forward diode characteristics indicates high robustness of the recess process. The reverse blocking capability of the diode is better than –110 V. Physical-based device simulations give insight in the respective electronic mechanisms. Zusammenfassung In dieser Arbeit wurden Galliumnitrid (GaN)-basierte Hochspannungs-HEMTs (High Electron Mobility Transistor) für Hochleistungsschalt- und Regelanwendungen in der Raumfahrt untersucht. Effizientes Leistungsschalten erfordert einen Betrieb bei hohen Sperrspannungen gepaart mit niedrigem Einschaltwiderstand, geringer dynamischer Dispersion und minimalen Leckströmen. Dabei wird das aus dem Halbleitermaterial herrührende Potential für extrem spannungsfeste Transistoren aufgrund mehrerer Faktoren aus dem lateralen und dem vertikalen Bauelementedesign oft nicht erreicht. Physikalisch-basierte Simulationswerkzeuge für die Bauelemente wurden daher entwickelt. Die damit durchgeführte Analyse der unterschiedlichen Transistorbetriebszustände ermöglichte das Entwickeln innovativer Bauelementdesignkonzepte. Das Erhöhen der Bauelementsperrspannung erfordert parallele und ineinandergreifende Lösungsansätze für die Epitaxieschichten, das strukturelle und das geometrische Design und für die Prozessierungstechnologie. Neuartige Bauelementstrukturen mit einer rückseitigen Kanalbarriere (back-barrier) aus AlGaN oder Kohlenstoff-dotierem GaN in Kombination mit neuartigen geometrischen Strukturen wie den Mehrfachgitterfeldplatten (MGFP, Multiple-Grating-Field-Plate) wurden untersucht. Die elektrische Gleichspannungscharakterisierung zeigte dabei eine signifikante Verringerung der Leckströme im gesperrten Zustand. Dies resultierte bei nach wie vor sehr kleinem Einschaltwiderstand in einer Durchbruchspannungserhöhung um das etwa Zehnfache auf über 1000 V. Vorzeitige Spannungsüberschläge aufgrund von Feldstärkenspitzen an Verbindungsmetallisierungen werden durch ein geschickt gestaltetes Bauelementlayout verhindert. Eine Optimierung der Halbleiterisolierung zwischen den aktiven Strukturen führte auch im kV-Bereich zu vernachlässigbaren Leckströme. Während das Hauptaugenmerk der Arbeit auf der Erhöhung der Spannungsfestigkeit im Vorwärtsbetrieb des Transistors lag, ist für einige Anwendung auch ein rückwärtiges Sperren erwünscht. Für Schaltverstärker im S-Klassenbetrieb wurde ein neuartiger GaN-HEMT entwickelt, dessen rückwärtiges Sperrverhalten durch einen tiefgelegten Schottkykontakt als Drainelektrode hervorgerufen wird. Eine derartige Struktur ergab eine rückwärtige Spannungsfestigkeit von über 110 V.

Download or read book Radiation Response and Reliability of High Speed AlGaN GaN HEMTs written by Jin Chen and published by . This book was released on 2016 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gallium Nitride and Silicon Carbide Power Technologies written by K. Shenai and published by The Electrochemical Society. This book was released on 2011 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 High mobility 2DEGs at AlGaN GaN Interfaces Grown by PA MBE and the Transport Study written by Yuxing Ren and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: AlGaN/GaN high-mobility transistor (HEMT) has been attracting people's attention and is proved to have satisfactory performance due to its related properties such as high break-down voltage, high saturation velocity, high frequency, etc. Molecular Beam Epitaxy (MBE) is one of the methods used for growth of high-quality AlGaN/GaN heterostructure with a two-dimensional electron gas (2DEG) in between. The high mobility of the 2DEGs, which is essential for ideal device performance, is determined by the charge density of the 2DEG. It is influenced by not only Al composition and AlGaN thickness, but also by dislocation density and the MBE background impurity. In order to achieve a high mobility, the relationship of mobility and 2DEG charge density is studied systematically on samples with various Al composition and AlGaN thickness grown by plasma-assisted MBE. Hall measurement is adopted for the measurement of 2DEG mobility and corresponding charge density. GaN bulk substrate and GaN template substrate with different dislocation densities are used for MBE growth as a comparison study on the influence of dislocation density. A gate control method is also explored on one specific sample with fixed dislocation density and background impurity to experimentally study the relationship of mobility and 2DEG density. Temperature-dependent Hall measurement is conducted to study transport property at low-temperature where the mobility is mainly limited by dislocation and background impurity rather than phonons. By analyzing the experimental data and comparing with theoretical calculations, the influence of dislocation density and background impurity is explained.

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2616 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A1GaN GaN HEMTs Grown by Molecular Beam Epitaxy on Sapphire SiC and HVPE GaN Templates written by Nils G. Weimann and published by . This book was released on 2002 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Beam Epitaxy of GaN and related alloys is becoming a rival to the more established Metalorganic Vapor Phase Epitaxy. Excellent control of impurity, interface abruptness, and in- situ monitoring of the growth are driving the increase in quality of MBE epilayers. We have developed nucleation schemes with plasma-assisted MBE on three types of substrates, consisting of sapphire, semi-insulating (SI- ) SiC, and HVPE SI-GaN templates on sapphire. While sapphire and SI-SiC are established substrates for the growth of AlGaN/GaN HEMT epilayers, HVPE GaN templates may provide a path to low-cost large-diameter substrates for electronic devices. We compare device results of HEMTs fabricated on these substrates. As a metric for device performance, the saturated RF power output in class A operation is measured at 2 GHz. We achieved a saturated power density of 2.2 W/mm from HEMTs on sapphire, 1.1 W/mm from HEMTs on HVPE GaN templates on sapphire, and 6.3 W/mm from HEMTs on semi-insulating 611-SiC substrates. The difference in output power can be attributed to self-heating due to insufficient thermal conductivity of the sapphire substrate, and to trapping in the compensation- doped HVPE template.

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 Handbook for III V High Electron Mobility Transistor Technologies written by D. Nirmal and published by CRC Press. This book was released on 2019-05-14 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focusses on III-V high electron mobility transistors (HEMTs) including basic physics, material used, fabrications details, modeling, simulation, and other important aspects. It initiates by describing principle of operation, material systems and material technologies followed by description of the structure, I-V characteristics, modeling of DC and RF parameters of AlGaN/GaN HEMTs. The book also provides information about source/drain engineering, gate engineering and channel engineering techniques used to improve the DC-RF and breakdown performance of HEMTs. Finally, the book also highlights the importance of metal oxide semiconductor high electron mobility transistors (MOS-HEMT). Key Features Combines III-As/P/N HEMTs with reliability and current status in single volume Includes AC/DC modelling and (sub)millimeter wave devices with reliability analysis Covers all theoretical and experimental aspects of HEMTs Discusses AlGaN/GaN transistors Presents DC, RF and breakdown characteristics of HEMTs on various material systems using graphs and plots