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 Microwave Power AlGaN GaN Heterojunction Field Effect Transistor for X band Applications written by Shujun Cai and published by . This book was released on 2002 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Current Trends In Heterojunction Bipolar Transistors written by M F Chang and published by World Scientific. This book was released on 1996-01-29 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in communication, digital signal processing and computational systems demand very high performance electronic circuits. Heterojunction Bipolar Transistors (HBTs) have the potential of providing a more efficient solution to many key system requirements through intrinsic device advantages. This book reviews the present status of GaAs, InP and silicon-based HBT technologies and their applications to digital, analog, microwave and mixed-signal circuits and systems. It represents the first major effort to cover the complete scope of the HBT technology development in the past decade, starting from the fundamental device physics, material growth, device reliability, scaling, processing, modeling to advanced HBT integrated circuit design for various system applications.

Download or read book Investigation of GaInP GaAs Double Heterojunction Bipolar Transistors for Microwave Power Amplifier Applications written by Pin-Fan Chen and published by . This book was released on 2001 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AlGaN GaN High Electron Mobility Transistors on Silicon Substrate for RF microwave Applications written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Xiii, 87 leaves : ill. ; 30 cm.

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 AlGaN GaN High Electron Mobility Transistors on Silicon Substrate for RF microwave Applications written by Shuo Jia and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Current Gain Improvement of AlGaN GaN Heterojunction Bipolar Transistors written by Yu Teng Tseng and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Studies on Gallium Arsenide Heterojunction Bipolar Transistors HBTs for Microwave Power Applications written by Wah Peng Neo and published by . This book was released on 2006 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Compound Semiconductor written by and published by . This book was released on 1998 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Characterisation and Numerical Simulation of Double Heterojunction Bipolar Transistors for Microwave Power Applications written by Mohammed Sotoodeh and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 AlGaN GaN Microwave Power High mobility transistors written by Yifeng Wu and published by . This book was released on 1997 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Distributed Power Amplifiers for RF and Microwave Communications written by Narendra Kumar and published by Artech House. This book was released on 2015-06-01 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new resource presents readers with all relevant information and comprehensive design methodology of wideband amplifiers. This book specifically focuses on distributed amplifiers and their main components, and presents numerous RF and microwave applications including well-known historical and recent architectures, theoretical approaches, circuit simulation, and practical implementation techniques. A great resource for practicing designers and engineers, this book contains numerous well-known and novel practical circuits, architectures, and theoretical approaches with detailed description of their operational principles.

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.