Download or read book Positron Beam Studies of Fluorine Implanted Gallium Nitride and Aluminium Gallium Nitride written by Chung-Choi Cheng and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Positron Beam Studies of Fluorine Implanted Gallium Nitride and Aluminium Gallium Nitride" by Chung-choi, Cheng, 鄭仲材, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b4327857 Subjects: Gallium nitride Aluminum nitride Positron beams Semiconductors - Spectra
Download or read book Positron Beam Studies of Fluorine Implanted Gallium Nitride and Aluminium Gallium Nitride written by Chung-choi Cheng and published by . This book was released on 2009 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Luminescence Studies of Ion Implanted Gallium Nitride and Aluminum Gallium Nitride written by Erin N. Claunch and published by . This book was released on 2003-03 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, research on the wide bandgap semiconductors such as GaN and Al(x)Ga(1-x)N became very popular for their applications on various devices. Therefore comprehensive and systematic luminescence studies of Si implanted Al(x)Ga(1-x)N, Mg doped GaN, and Si+N implanted GaN grown on sapphire substrates by molecular beam epitaxial method have been made as a function of ion dose and anneal temperature.
Download or read book Gallium Nitride Processing for Electronics Sensors and Spintronics written by Stephen J. Pearton and published by Springer Science & Business Media. This book was released on 2006-02-24 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor spintronics is expected to lead to a new generation of transistors, lasers and integrated magnetic sensors that can be used to create ultra-low power, high speed memory, logic and photonic devices. Useful spintronic devices will need materials with practical magnetic ordering temperatures and current research points to gallium and aluminium nitride magnetic superconductors as having great potential. This book details current research into the properties of III-nitride semiconductors and their usefulness in novel devices such as spin-polarized light emitters, spin field effect transistors, integrated sensors and high temperature electronics. Written by three leading researchers in nitride semiconductors, the book provides an excellent introduction to gallium nitride technology and will be of interest to all reseachers and industrial practitioners wishing to keep up to date with developments that may lead to the next generation of transistors, lasers and integrated magnetic sensors.
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 Luminescence Study of Ion Implanted Gallium Nitride written by Eric Silkowski and published by . This book was released on 1996-11-01 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Luminescence and absorption measurements were used to demonstrate the efficacy of ion implantation for introducing various classes of dopants into GaN. A wide range of implantation and annealing studies were performed with several dopant species (Ar, Zn, C, O, Si, Be, Mg, Nd, Er). Room temperature ion implantation was performed on MOCVD- and MBE-grown GaN samples at energies between 100 and 1150 keV with doses ranging from 1 x 10(exp 13) to 1 x 10 (exp 15)/sq cm. Conventional furnace annealing in flowing NH3 or N2 gas resulted in good implantation damage recovery at an annealing temperature of 1000 deg C for 90 min. Annealing temperature was found to be the determining factor in implantation damage recovery. It was discovered that surface degradation occurred for annealing in an NH3 environment at temperatures above 1000 deg C. An optimal annealing temperature of 1000 deg C and an optimal annealing gas environment of NH3 were found for the optical activation of Zn, Mg, Er, and Nd. Several new luminescence features were observed for the various dopants. Zn- implanted GaN was found to have a strong luminescence peak in the blue at 2.86 eV. The energetic location and width of this luminescence peak was insensitive to temperature changes and excitation intensity changes. These properties suggested that an internal Zn center transition was responsible.
Download or read book Gallium Nitride and Related Materials II Volume 468 written by C. R. Abernathy and published by Materials Research Society. This book was released on 1997-08-13 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book from MRS dedicated to III-Nitrides, focuses on developments in AlN, GaN, InN and their alloys that are now finding application in short-wavelength lasers (~400nm, cw at room temperature) and high-power electronics (2.8W/mm at GHz). Experts from fields including crystal growth, condensed matter theory, source chemistry, device processing and device design come together in the volume to address issues of both scientific and technological relevance. And while much of the book reports on advances in material preparation and the understanding of defect issues, similar advances in material and device processing are also reported. Topics include: growth and doping; substrates and substrate effects; characterization; processing and device performance and design.
Download or read book Electrical Activation Studies of Silicon Implanted Aluminum Gallium Nitride with High Aluminum Mole Fraction written by Elizabeth A. Moore and published by . This book was released on 2007 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research demonstrates a method for producing highly conductive Si-implanted n-type aluminum gallium nitride (AlxGa1-xN) alloys, and represents a comprehensive analysis of the resulting material's electrical and optical properties as a function of Al mole fraction, anneal temperature, anneal time, and implantation dose. Highly conductive alloys are critical to the fabrication of devices operating in deep UV, high-temperature, high-power, and high-frequency environments, and thus this research is significant in regard to the application of such devices. The AlxGa1-xN wafers of this study, with Al concentrations of 10 to 50%, were implanted at room temperature with silicon ions at energies of 200 keV with doses of 1x1014, 5x1014, and 1x1015 cm-2 and annealed from 1100 to 1350 C for 20 to 40 minutes in flowing nitrogen. Excellent activation was achieved for each of the implanted silicon doses for all of the five Al mole fractions studied, with most activation efficiencies above 90%. These activation efficiencies are the highest reported activations, to the best of my knowledge. The mobilities were found to decrease as the Al concentration of the AlxGa1-xN was increased from 10 to 50% and also as the implanted silicon dose was increased. Typical mobilities ranged from 101 cm2/V s for the Al0.1Ga0.9N implanted with 1x1014 cm-2 silicon ions to 35 cm2/V s obtained for the Al0.5Ga0.5N implanted with 1x1015 cm-2 silicon ions. The cathodoluminescence results support the electrical results in determining the optimal annealing conditions.
Download or read book Gallium Nitride and Related Materials written by and published by . This book was released on 1996 with total page 1014 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoluminescence and Electrical Studies of Fluorine and Lithium Implanted Gallium Phosphide and Germanium written by Bryan Stephen Seymour and published by . This book was released on 1982 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aluminum Gallium Nitride written by David DiSanto and published by . This book was released on 2005 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decade, All-, GaXN/GaN High Electron Mobility Transistors (HEMTs) have been intensively studied because their intrinsic electrical properties make them attractive for high power microwave device applications. Despite much progress, current slump continues to be a problem, limiting output power, reducing reliability, and complicating device modelling. In this work, a complete AĨ-, G, ̃N/GÑ HEMT fabrication procedure was developed, and electrical characteristics related to current slump, microwave modelling, and delay time analysis were explored. Low resistance ohmic contacts were achieved, enabling high channel current densities. Schottky contacts were developed with a new ion implant isolation architecture, enabling gate leakage currents 2 to 4 orders of magnitude lower than typical results from the literature. Through pulsed current-voltage measurements, the importance of bias stresses in the gate-source region was demonstrated for the first time. In contrast to the conventional "virtual gate" model, gate-source stresses were shown to be more important than gatedrain stresses when biased near threshold. Slow slump transients were studied by passivating transistor surfaces with ultrathin layers. These results excluded dielectric strain and electron injection reduction as viable passivation mechanisms. A novel model was proposed associating slow slump behaviour with trapping of many electrons at screw dislocation sites. The effect of slump on RF properties was examined through microwave measurements by extracting the parasitic source and drain resistances without special biasing. Besides significantly improving the accuracy of small-signal modelling, we were able to show the bias dependence of parasitic resistances which confirmed the effect of source-side bias stressing. The question of channel electron velocities in nitride transistors remains controversial. We determined an effective electron velocity of - 1.9 x 1 o7 cmls through two methods. We first extracted effective velocities through delay time analysis, and then through the small-signal model elements. To our knowledge, this was the first time an equivalent model extraction led to self-consistent electron velocity values for nitride transistors. Finally, our equivalent circuit model showed the correct interrelation between frequency response and access resistances. The cohesive picture of current slump, equivalent circuit model extraction, and delay time analysis gives a high degree of confidence in these results.
Download or read book Transmission Electron Microscopy Studies of Gallium Nitride Nanostructures Grown by Molecular Beam Epitaxy written by and published by . This book was released on 2010 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigations of the Gallium Nitride Aluminum Nitride and Indium Nitride Semiconductors Structural Optical Electronic and Interfacial Properties written by Samuel Clagett Strite (III) and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Described in this thesis is an investigation of some fundamental physical properties of both zincblende and wurtzite Group III - Nitride wide bandgap semiconductor materials. All of the thin films studied were grown by plasma-enhanced molecular beam epitaxy on either GaAs and SiC substrates. This growth method proved to be suitable for nitride expitaxial growth although compromises between the plasma power and the crystal growth rate had to be sought. The zincblende polytypes of GaN and InN were studied with the intent of evaluating their potential as a wide bandgap semiconductor system for short wavelength optical devices. The metastability of these crystals has led us to the conclusion that the zincblende nitrides are not a promising candidate for these applications due to their tendency to nucleate wurtzite domains. Bulk samples of zincblende GaN and InN and wurtzite GaN, AlN and InN were studied by x-ray photoemission spectroscopy (XPS) in an effort to determine their valence band structure. We report the various energies of the valence band density of states maxima as well as the ionicity gaps of each material. Wurtzite GaN/AlN and InN/AlN heterostructures were also investigated by XPS in order to estimate the valence band discontinuities of these heterojunctions. We measured valence band discontinuities of $Delta$E$rmsbsp{v}{GaN/AlN}$ = 0.4 $pm$ 0.4 eV and $Delta$E$rmsbsp{v}{InN/AlN}$ = 1.1 $pm$ 0.4 eV. Our results indicate that both systems have heterojunction band lineups fundamentally suitable for common optical device applications.
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2007 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cyclotron Produced Radionuclides written by International Atomic Energy Agency and published by . This book was released on 2009 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Application of radioisotopes has shown significant growth in the past decade, and a major factor contributing towards this growth is the availability of a large number of cyclotrons dedicated to the production of radioisotopes for medical applications. Although there are many articles in journals on cyclotrons and their use for radioisotope production, there is no single source of information for beginners on radioisotope production using cyclotrons. This publication attempts to address this deficiency. Its contains chapters on accelerator technology, theoretical considerations of nuclear reactions, the technology behind targetry, techniques on preparation of targets, irradiation of targets under high beam currents, target processing and target recovery.
Download or read book Ion solid Interactions Author title index written by Walter M. Gibson and published by . This book was released on 1980 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Modern Ion Beam Materials Analysis written by Yongqiang Wang and published by Materials Research Society. This book was released on 2010-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Modern Ion Beam Materials Analysis, 2nd Edition is a compilation of updated techniques and data for use in the ion-beam analysis of materials. The information presented is unavailable collectively from any other source, and places a strong emphasis on practical examples of the analysis techniques as they are applied to common problems. Revised and updated from the popular handbook previously released in 1995, this edition is written and compiled by over 30 leading authorities in the field of ion beam analysis and is an important reference tool for technicians, students and professionals. It is an excellent introduction to the fundamentals and lab practices of ion beam analysis and useful as a teaching text for undergraduate senior or first-year graduate students. It is the most recent and comprehensive collection of nuclear and atomic data for the applications of ion beam materials analysis.
