Deeply Scaled Gan High Electron Mobility Transistors For Radio Frequency Applications
DOWNLOAD
Download Deeply Scaled Gan High Electron Mobility Transistors For Radio Frequency Applications PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Deeply Scaled Gan High Electron Mobility Transistors For Radio Frequency Applications book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Deeply Scaled Gan High Electron Mobility Transistors For Radio Frequency Applications
DOWNLOAD
Author : Dong Seup Lee
language : en
Publisher:
Release Date : 2014
Deeply Scaled Gan High Electron Mobility Transistors For Radio Frequency Applications written by Dong Seup Lee and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The performance of GaN devices has increased continuously in the last two decades. However, in spite of the improvements, there are still several critical issues limiting the high frequency operation of these devices. One of the key challenges is the lower-than-expected maximum current gain cutoff frequency (fT) of deeply-scaled GaN HEMTs. The fT of the short channel devices is well below both projections from maximum frequency in the long channel devices and theoretical expectations based on material properties. Another important issue is a roll-off of the device frequency performance under wide bias range, which limits the large-signal high speed operation in the deeply-scaled devices. This thesis focuses on these two important problems and investigates them both analytically and experimentally. First, through systematic study of the transistor delay, the critical factors limiting intrinsic and extrinsic device speed are clarified and several technologies are demonstrated to overcome these limits. This has allowed the demonstration of state-of-the-art high frequency performance GaN HEMTs. Second, in order to understand the origin of the decrease in device speed at high drain and gate bias, a new extraction method and novel transistor structure have been developed, which provide an excellent guide for future device optimization.
A Compact Transport And Charge Model For Gan Based High Electron Mobility Transistors For Rf Applications
DOWNLOAD
Author : Ujwal Radhakrishna
language : en
Publisher:
Release Date : 2013
A Compact Transport And Charge Model For Gan Based High Electron Mobility Transistors For Rf Applications written by Ujwal Radhakrishna and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013 with categories.
Gallium Nitride (GaN)-based high electron mobility transistors (HEMTs) are rapidly emerging as front-runners in high-power mm-wave circuit applications. For circuit design with current devices and to allow sensible future performance projections from device engineering in such a rapidly evolving technology, compact device models are essential. In this thesis, a physics-based compact model is developed for short channel GaN HEMTs. The model is based on the concept of virtual source (VS) transport originally developed for scaled silicon field effect transistors. Self-consistent current and charge expressions in the model require very few parameters. The parameters have straightforward physical meanings and can be extracted through independent measurements. The model is implemented in Verilog-A and is compatible with state of the art circuit simulators. The new model is calibrated and validated with experimental DC I-V and S-parameter measurements of fabricated devices. Using the model, a projection of cut-off frequency (f-[tau]) of GaN-based HEMTs with scaling is performed to highlight performance bottlenecks.
Millimeter Wave Gan High Electron Mobility Transistors And Their Integration With Silicon Electronics
DOWNLOAD
Author : Jinwook Will Chung
language : en
Publisher:
Release Date : 2011
Millimeter Wave Gan High Electron Mobility Transistors And Their Integration With Silicon Electronics written by Jinwook Will Chung and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
In spite of the great progress in performance achieved during the last few years, GaN high electron mobility transistors (HEMTs) still have several important issues to be solved for millimeter-wave (30 ~ 300 GHz) applications. One of the key challenges is to improve its high frequency characteristics. In this thesis, we particularly focus on fT and fma, two of the most important figures of merit in frequency performance of GaN HEMTs and investigate them both analytically and experimentally. Based on an improved physical understanding and new process technologies, we aim to demonstrate the state-of-the-art high frequency performance of GaN HEMTs. To maximize fmax, parasitic components in the device (Ri, R, Rg, Cgd, and go) are carefully minimized and the optimized 60-nm AlGaN/GaN HEMT shows a very high fmax of 300 GHz. The lower-than-expected fT observed in many AlGaN/GaN HEMTs is attributed to a significant drop of the intrinsic transconductance at high frequency (RF gm) with respect to the intrinsic DC g. (called RF gm-collapse). By suppressing RF gm-collapse and harmoniously scaling the device, a record fT of 225 GHz is achieved in the 55-nm AlGaN/GaN HEMT. Another important challenge for the wide adoption of GaN devices is to develop suitable technology to integrate these GaN transistors with Si(100) electronics. In this thesis, we demonstrate a new technology to integrate, for the first time, GaN HEMTs and Si(100) MOSFETs on the same chip. This integration enables the development of hybrid circuits that take advantage of the high-frequency and power capability of GaN and the unsurpassed circuit scalability and complexity of Si electronics.
Reliability Of Gan High Electron Mobility Transistors On Silicon Substrates
DOWNLOAD
Author : Sefa Demirtas
language : en
Publisher:
Release Date : 2009
Reliability Of Gan High Electron Mobility Transistors On Silicon Substrates written by Sefa Demirtas and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with categories.
GaN High Electron Mobility Transistors are promising devices for high power and high frequency applications such as cellular base stations, radar and wireless network systems, due to the high bandgap and high breakdown field of GaN. However, their reliability is the main hindrance to the deployment of these transistors in a wide scale. In this study, we have investigated the reliability of GaN HEMTs grown on Si substrates. The large lattice and thermal mismatch between GaN and Si adds an additional reliability concern as compared to conventional substrates such as SiC and sapphire. We have performed systematic electrical stress experiments to understand the physics of degradation in these devices. Relevant device parameters are recorded continuously during these stress tests by a benign characterization suite. We conclude from these experiments that high voltage stress conditions are more effective in degrading the device than high current conditions. High voltage stress is found to impact the device in two different ways. The first is increased trapping in the large number of traps in the highly mismatched device structure even before any stress. The second is through the converse piezoelectric effect discussed by Joh et al. for GaN-on-SiC devices. We also have found evidence that these two mechanisms are connected. We have used UV illumination to enhance detrapping and shown that trapped electrons screen the electric field in the device and increase the critical voltage at which gate current degrades.
Advanced Technologies For Improving High Frequency Performance Of Algan Gan High Electron Mobility Transistors
DOWNLOAD
Author : Jinwook Will Chung
language : en
Publisher:
Release Date : 2008
Advanced Technologies For Improving High Frequency Performance Of Algan Gan High Electron Mobility Transistors written by Jinwook Will Chung and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008 with categories.
In this thesis, we have used a combination of physical analysis, numerical simulation and experimental work to identify and overcome some of the main challenges in AlGaN/GaN high electron mobility transistors (HEMTs) for high frequency applications. In spite of their excellent material properties, GaN-based HEMTs are still below the theoretical predictions in their high frequency performance. If the frequency performance could be improved, the superior breakdown characteristics of nitride semiconductors would make these devices the best option for power amplifiers at any frequency. To achieve this goal, we have first identified some critical parameters that limit the high frequency performance of AlGaN/GaN HEMTs and then we have demonstrated several new technologies to increase the performance. Some of these technologies include advanced drain delay engineering, charge control in the channel and new N-face GaN HEMTs. Although more work is needed in the future to combine all these new technologies, the initial results are extremely promising.
Reliability Of W Band Inain Gan High Electron Mobility Transistors
DOWNLOAD
Author : Yufei Wu (Ph. D.)
language : en
Publisher:
Release Date : 2017
Reliability Of W Band Inain Gan High Electron Mobility Transistors written by Yufei Wu (Ph. D.) and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017 with categories.
AlGaN/GaN High Electron Mobility Transistors (HEMTs) have enjoyed tremendous market growth in RF power amplifiers over the past decades. In the quest for enhancing the operating frequency of GaN HEMTs, there has been a great effort to scale down the gate length. Maintaining acceptable short-channel effects requires shrinking the barrier thickness at the same time. However, a limitation exists since there is a minimum barrier thickness that is needed to obtain a sufficiently high two-dimensional electron gas density. One possible solution to this problem is the use of a new barrier material, i.e., InAlN. Due to its high spontaneous polarization, if InAlN is used as a barrier material in GaN HEMTs, a much smaller layer thickness is required compared with conventional HEMTs. This enables further barrier thickness scaling and therefore gate length scaling and a higher frequency response. However, as a relatively new structure, reliability studies of InAlN/GaN HEMTs are still lacking. Solid reliability is essential before the wide commercial deployment of this new technology. This thesis investigates the most relevant degradation mechanisms under important stress regimes, aiming at building a comprehensive understanding of InAIN/GaN HEMT reliability. Through investigating various voltage, current, and temperature stress levels, we have identified one recoverable degradation mechanism as well as three permanent degradation mechanisms. Under high drain voltage, hot-electron trapping results in temporary drain current decrease and drain resistance increase. In addition, under high drain voltage but relatively low drain current level, permanent negative threshold voltage shift and drain current increase have been observed. We attribute the phenomena to dehydrogenation of pre-existing defects in GaN channel by hot electrons. Under high positive gate bias, defect generation in the AIN interlayer due to high electric field across AIN has proven to be responsible for the observed gate leakage current increase. Also, under high-power stress conditions, positive threshold voltage shift and maximum drain current decrease have been consistently observed. We verified through both thermal stress experiments and Transmission Electron Microscopy (TEM) analysis that Schottky gate sinking is the cause. This work provides fundamental understanding of potential reliability concerns in InAlN/GaN HEMTs and is essential in accelerating the future commercialization of this promising technology.
Fabrication And Electrical Measurements Of Gallium Nitride High Electron Mobility Transistors
DOWNLOAD
Author : Yi Fan Qi
language : en
Publisher:
Release Date : 2014
Fabrication And Electrical Measurements Of Gallium Nitride High Electron Mobility Transistors written by Yi Fan Qi and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
"Gallium nitride (GaN) high electron mobility transistors (HEMTs) have a potential in electronic fields such as broadband communication and radar applications. GaN possesses many advantages including a direct and wide bandgap, making GaN HEMTs ideal to high voltage and high temperature. Experiments have yielded devices with high power output efficiency and bandwidth compared to other modern transistor devices. In this work, GaN HEMTs on silicon substrates with various gate lengths have been designed and fabricated. The current-voltage characteristics and breakdown voltages of the HEMTs have been measured. The design, fabrication, and characterization of different devices were presented, as well as the measurements and discussion of devices under effects of heat treatment. Although the fabrication technology is still immature and under development, GaN HEMTs have shown promising results in radio frequency, high power, and wireless power transfer applications. The goal of this work is to investigate the electrical properties of the GaN HEMTs and to develop this technology in high power devices in the future." --
Gallium Nitride Gan
DOWNLOAD
Author : Farid Medjdoub
language : en
Publisher: CRC Press
Release Date : 2017-12-19
Gallium Nitride Gan written by Farid Medjdoub and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-12-19 with Technology & Engineering categories.
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.
Advanced Gan Devices And Technology For Rf And Power Switching Applications
DOWNLOAD
Author : Bo Song
language : en
Publisher:
Release Date : 2016
Advanced Gan Devices And Technology For Rf And Power Switching Applications written by Bo Song and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
GaN-based devices show great potential for high-speed RF power applications as well as power switching applications due to the high electron velocity and high breakdown field in GaN over Si, GaAs and SiC. Another unique property of III-V nitride materials (GaN, AlN, InN) is polarization, which can be engineered to induce 2-dimensional electron gas (2DEG) at heterojunction interfaces as well as induce 3-D electron gas in thick (bulk) layers by grading the alloy composition of the layers, e.g. AlGaN, without impurity doping. This unconventional doping scheme is termed as polarization-doping or Pi-doping. This work focuses on device development and proposals to advance GaN technologies for RF and power switching applications. During the quest to realize THz GaN transistors, it has been identified that the ultimate factors limiting the GaN high electron mobility transistors (HEMTs) are the intrinsic transconductance (gm) and the fringing capacitance (Cfringing) associated with the T-gate: speed gm/Cfringing. In InAlN/GaN HEMTs, the device current gain cut-off speed is increased from 230 GHz to >300 GHz by reducing Cfringing and further increased to ~ 400 GHz by improving gm. Effects of scaling the source-drain distance on ultra-scaled devices are also studied. Low leakage and low current collapse (or frequency dispersion) are crucial for transistors. A record-low leakage of 1x10-12 A/mm simultaneously with a low current collapse is achieved in AlGaN/GaN-on-Si HEMTs employing the regrown ohmic contact technology. The device improvement is attributed to the contact regrowth since generation of surface traps is minimized by avoiding the conventional high temperature annealing process to form alloyed ohmic contacts. For high-voltage high-current power switching applications (>100 kW), vertical devices are highly desirable over lateral ones. To this end, we have proposed a series of GaN devices grown on bulk GaN substrates and employing the unique feature in the GaN material family - polarization doping. Analytical modeling suggests that at the same breakdown voltage, a up to 2x lower specific on-resistance (Ron,sp) can be achieved in Pi-doped devices compared to impurity doped GaN power devices. High voltage impurity and Pi-doped GaN p-n diodes with a breakdown voltage (BV) >1.2 kV and avalanche breakdown capability have been developed experimentally. Another concept called GaN Lateral Polar Super Junctions (LPSJ) is also proposed and theoretically analyzed, featuring uniformly Pi-doped n/p-pillars to overcome the conventional tradeoff between BV and Ron,sp in a unipolar drift region of a power device. The design space for GaN LPSJs is explored using a 2D analytical model of BV and Ron,sp under both charge balanced and imbalanced conditions.
Algan Gan High Electron Mobility Transistors On Silicon Substrate For Rf Microwave Applications
DOWNLOAD
Author : Shuo Jia
language : en
Publisher:
Release Date : 2005
Algan Gan High Electron Mobility Transistors On Silicon Substrate For Rf Microwave Applications written by Shuo Jia and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2005 with Gallium nitride categories.