Download or read book Growth and Fabrication of GaN Based Heterojunction Bipolar Transistors written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: GaN HBTs are promising for microwave power applications but face numerous technology barriers. In this project, we are addressing the enhancement of the hole concentration in p-type GaN by piezoelectric effects and/or the use of superlattices. We are currently assessing the activity of Mg-doped GaN on sapphire and lithium gallate as grown by MBE. In addition, we are modeling these effects to optimize the hole concentration in realistic HBT structures.

Download or read book Growth and Fabrication of GaN Based Heterojunction Biopolar Transistors written by and published by . This book was released on 2000 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this progress report, we summarize the results to date of experiments to prove the existence of a two dimensional hole gas. If possible, this hole gas will result in enhanced performance Heterojunctions bipolar transistors for military and commercial applications. Also summarized is the background work required to achieve the two dimensional hole gas including several never before reported results on the behavior of p-type dopants in III-Nitrides.

Download or read book Design and Fabrication of GaN based Heterojunction Bipolar Transistors written by Kyu-Pil Lee and published by . This book was released on 2003 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Design and Fabrication of Gallium Nitride silicon Carbide Heterojunction Bipolar Transistors written by Hong Wu and published by . This book was released on 2003 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Growth and Fabrication of GaN written by and published by . This book was released on 1999 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: A GaN/AlGaN heterojunction bipolar transistor structure with Mg doping in the base and Si Doping in the emitter and collector regions was grown by Metal Organic Chemical Vapor Deposition in c-axis Al(2)O(3). Secondary Ion Mass Spectrometry measurements showed no increase in the O concentration (2-3x10(18) cm( -3)) in the AlGaN emitter and fairly low levels of C (~4-5x10(17) cm ( -3)) throughout the structure. Due to the non-ohmic behavior of the base contact at room temperature, the current gain of large area (~90 um diameter) devices was

Download or read book Development of GaN based PNP Heterojunction Bipolar Transistors written by Daniel S. Green and published by . This book was released on 2006 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: GaN-based electronics have progressed mightily in the last 15 years. The primary focus of this development has been the AlGaN/GaN heterostructure FET, with the commercialization of this device in progress. Bipolar transistors however offer a few key potential advantages over the FET device, including the primary advantage of normally off operation. Additionally, the pnp heterostructure bipolar transistor (HBT) in particular offers more attractive base performance relative to the npn HBT. The pnp HBT also serves as an excellent test vehicle for the several material parameters of p-Gan that remain poor defined. However, implementation of the pnp HBT has been limited by the difficulty contacting p-GaN collector material.

Download or read book Material and Device Studies for the Development of Gallium Nitride Heterojunction Bipolar Transistors by Molecular Beam Epitaxy written by Wei Li and published by . This book was released on 2008 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Due to its unique physical properties, gallium nitride (GaN) is under intense investigation for the development of transistors for high power, high frequency and high temperature applications. The majority of existing literature addresses field effect transistors. This dissertation addresses a wide spectrum of materials and device studies required for the development of GaN-based heterojunction bipolar transistors (HBTs). The investigated structure has the emitter region based on n-Al x Ga 1-x N alloys, while the base and collector were based on p-In y Ga 1-y N and n-GaN, respectively. The growth and doping of the various layers of the transistor structure, on sapphire substrate, GaN-templates and free standing GaN substrates are addressed. Particular emphasis was placed on the p-type doping of the AlGaN and InGaN alloys with magnesium, both doping of bulk films as well as superlattices. The experimental results were compared with theoretical predictions of a self-consistent solution to the one-dimensional poisson and schrodinger equations. A hole concentration for p-InGaN of 9x10 18 CM -3 was obtained, which is the highest value published. The device aspect of this research addressed issues related to the development of novel methods of selective growth by molecular beam epitaxy (MBE) of the emitter onto the base. This was found to be necessary to avoid damage of the base during mesa etching. The final product of this research was the fabrication and DC characterization of HBT devices. This included various lithography, metallization, etching and annealing steps. The devices were evaluated under common base and common emitter configurations and the best result obtained was a room temperature gain of 59.

Download or read book Wideband Transferred Substrate AlGaN GaN Heterojunction Bipolar Transistors for Microwave Power Applications written by and published by . This book was released on 2001 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report reviews efforts to develop growth and fabrication technology for the GaN HBT at UCSB. Conventional devices are grown by plasma assisted MBE on MOCVD GaN templates on sapphire and fully MOCVD devices. HBTs were also fabricated on LEO material identifying threading dislocations as the primary source of collector-emitter leakage which was reduced by 4 orders of magnitude for devices on non-dislocated material. Base doping studies show that the mechanism of this leakage is localized punch-through caused by compensation near the dislocation. The cause of the large offset voltage in common emitter characteristics is discussed. The Mg memory effect in MOCVD grown GaN HBTs is investigated and MBE grown device layers are shown to produce sharp doping profiles. The low current gain of these devices, (3-6) is discussed. An air bridge and etch back process is used to fabricate transistors compatible with RF testing. The devices had a common emitter dilferential current gain of 3.5 with a short circuit current gain cutoff frequency of 2 CHz and an emitter current density of over 6 kA/cmA2. Remaining issues are high base resistance, low current gain, and emitter mesa etch process development.

Download or read book Demonstration and Modeling of a Nitride based Heterojunction Bipolar Transistor Using Nanomembrane Transfer written by Clincy Cheung and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heterojunction bipolar transistors (HBT) are sought as a building block for implementation of modern broadband electronics, defense applications, and other mm-wave electronic systems demanding in high-speed and high-power performance. The push for greater frequency performance, higher power densities and reliability have pushed research towards wide-bandgap materials such as Gallium Nitride (GaN) given its superior intrinsic material properties, providing for higher breakdown voltage, and enabling higher power performance. However, GaN faces a fundamental limitation with p-type doping, limiting its adoption in RF power electronics. Attempts at a wide bandgap HBT to-date has exclusively relied on epitaxial growth using metal-organic chemical vapor deposition or molecular beam epitaxy (MBE) to fabricate a GaN-based transistor; however, none have yielded a device with both sufficient current gain and transition frequency - both key measures of performance in a bipolar transistor. Alternative materials for the different HBT layers have been considered but are limited by significant lattice mismatch. To bypass p-type GaN limitations and improve the base-collector junction with minimal interface trap density, a nanomembrane interlayer device transfer is proposed as an alternative for fabrication of an HBT. There are two aims in this dissertation: to demonstrate an experimental HBT with a sufficient current gain above 20 and demonstrate using computer-aided modeling that sufficient frequency performance can be achieved - both to demonstrate that a wide-bandgap HBT is both possible and worth further exploration for RF electronics. In Chapter 1, the landscape of research into wide-bandgap bipolar transistors is presented. In Chapter 2, multiple methods of integration for different diode pairs within the HBT are evaluated for probability of success in the overall device, where a GaAs-GaN base-collector diode is demonstrated to have the best performance using nanomembrane layer transfer. Additionally, an MBE-grown AlGaAs-GaAs film stack was transferred and demonstrated an emitter-base structure can be transferred with no degradation in performance. In Chapter 3, fabrication of the HBT is demonstrated using the best methods selected from Chapter 2, where a AlGaAs-GaAs-GaN HBT was demonstrated to have a current gain greater than 70. In Chapter 4, technology computer-aided design simulations were developed to validate the DC results shown in Chapter 2 and 3, and simulated transition frequencies of at least 60 GHz for the experimental structure fabricated in Chapter 3. Finally, in Chapter 5, next steps are outlined for exploration beyond this initial proof-of-concept device. Taken altogether, this dissertation serves to demonstrate a device structure with the potential to vastly exceed existing solutions that can be applied to a vast array of wide-bandgap materials without being limited by its p-type analogues, enabling performance for a wide array of applications in the next generations of electronics.

Download or read book Development of a Fabrication Process for InP InGaAs Based Heterojunction Bipolar Transistors written by Matthew Jon Soucek and published by . This book was released on 1994 with total page 364 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 An Exploration of GaN based Heterojunction Bipolar Transistors written by Ajay Raman and published by . This book was released on 2013 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collector-up HBT structure has the advantage of lower Base-Collector capacitance but the disadvantage of undesired injection and recombination of electrons from the emitter to the extrinsic base region. In addition, HBTs with graded base layers can be designed to obtain polarization hole doping as well as quasi electric field in the base similar to the N-polar HBTs while employing the more mature Ga-polar growth to grow the devices. The device results are presented and future challenges are presented.

Download or read book The Fabrication and Characterization of InP based Heterojunction Bipolar Transistors written by James C. Vlcek and published by . This book was released on 1985 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Growth Fabrication and Characterization of Gallium Nitrade Based Bipolar Transistors written by Huili Xing and published by . This book was released on 2003 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Fabrication of InGaN GaN Heterojunction Bipolar Transistors for Microwave Power Amplifiers written by David Martin Keogh and published by . This book was released on 2006 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The GaN material system is widely recognized for its opto-electronic properties, with the recent commercialization of blue, green, and violet light emitting devices, but also has enormous potential for high power applications across a range of frequencies. The combination of high breakdown field, high electron saturation velocity, and high thermal conductivity, make it especially useful for delivering high power at high frequencies for wireless base stations, emerging WiMAX technology, and satellite communications. Though HEMTs have shown impressive performance, HBTs have many advantages as compared to HEMTs, and therefore represent an important technology. Bipolar technology, however, has not achieved the same level of success as HEMTs, as a result of some important technological obstacles. For example, the main issue with GaN-based HBTs is the issue of acceptor impurity activation, which is typically less than 1% for GaN, limiting free hole concentrations to less than 1x1018 cm-3. Through the use of InGaN alloys in the base of an HBT, however, it is possible to achieve doping levels greater than 1x1019 cm-3, with higher mobilities and less lattice damage, enabling a high performance RF device. This dissertation embodies the design, fabrication, and characterization of InGaN/GaN HBTs under DC and RF conditions. Design of the epitaxial layer structure accounts for the piezo-electric and polarization effects present in the nitrides, which is critical for proper device operation. Furthermore, the DC and RF performance is simulated using physically based TCAD device design software to estimate the performance of an InGaN/GaN HBT. In addition, the performance of a fully-matched Class-B power amplifier is simulated at 1 GHz. Processing of InGaN/GaN HBTs was a significant portion of this thesis, and as such, a robust scheme for their fabrication was developed. Dry-etching was accomplished using Inductively Coupled Plasma (ICP), and the effects of etch conditions on the characteristics of the device explored. Also, boiling KOH solutions were found to be useful for improving the surface quality after dry-etching, and as part of a digital etching process. The final process enabled the successful fabrication of InGaN/GaN HBTs with excellent DC performance, and a maximum cut-off frequency of 0.8 GHz.

Download or read book Extreme Environment Electronics written by John D. Cressler and published by CRC Press. This book was released on 2017-12-19 with total page 1041 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world’s foremost experts in extreme environment electronics, the book provides in-depth information on a wide array of topics. It begins by describing the extreme conditions and then delves into a description of suitable semiconductor technologies and the modeling of devices within those technologies. It also discusses reliability issues and failure mechanisms that readers need to be aware of, as well as best practices for the design of these electronics. Continuing beyond just the "paper design" of building blocks, the book rounds out coverage of the design realization process with verification techniques and chapters on electronic packaging for extreme environments. The final set of chapters describes actual chip-level designs for applications in energy and space exploration. Requiring only a basic background in electronics, the book combines theoretical and practical aspects in each self-contained chapter. Appendices supply additional background material. With its broad coverage and depth, and the expertise of the contributing authors, this is an invaluable reference for engineers, scientists, and technical managers, as well as researchers and graduate students. A hands-on resource, it explores what is required to successfully operate electronics in the most demanding conditions.