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.

These two volumes present a complete description of the various methods of making and studying the crystal and electronic structure. The books also assist in determining the origin and the influence of defects in the intrinsic properties and of applying these materials for various optical (LEDs, lasers, detectors) and electronic (transistors, non-volatile memories) devices. These two volumes give a comprehensive description of both experimental and theoretical developments in the field of III-V nitrides over the past thirty years. The various chapters address issues related to crystal growth and structure, doping and alloy phenomena, band structure, optical and electronic properties, non-linear optical phenomena, the origin and the effect of strain in the hetero-epitaxy and the electronic structure, phonons, the theory and experimental observations of the effect of hydrogen, investigation of the electronic structure of defects using transport and magnetic resonance measurements, MQWs and superlattices, device processing and applications of these materials to LEDs, Lasers, Ultraviolet and X-ray Detectors, Transistors and non-volatile semiconductor memories. The various chapters were written by experts and an attempt has been made to address the topics in a tutorial fashion,including an historical review,a description of the state of the art, anticipation of future developments, and presentation of a complete list of references. The level of treatment of the various topics is appropriate for graduate students, laboratory practitioners, as well as experts in the field.

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.

This thesis outlines the principles, device physics, and technological applications of electronics based on the ultra-wide bandgap semiconductor aluminum nitride. It discusses the basic principles of electrostatics and transport properties of polarization-induced two-dimensional electron and hole channels in semiconductor heterostructures based on aluminum nitride. It explains the discovery of high-density two-dimensional hole gases in undoped heterojunctions, and shows how these high conductivity n- and p-type channels are used for high performance nFETs and pFETs, along with wide bandgap RF, mm-wave, and CMOS applications. The thesis goes on to discuss how the several material advantages of aluminum nitride, such as its high thermal conductivity and piezoelectric coefficient, enable not just high performance of transistors, but also monolithic integration of passive elements such as high frequency filters, enabling a new form factor for integrated RF electronics.

Semiconductor components based on silicon have been used in a wide range of applications for some time now. These elemental semiconductors are now well researched and technologically well developed. In the meantime the focus has switched to a new group of materials: ceramic semiconductors based on nitrides are currently the subject of research due to their optical and electronic characteristics. They open up new industrial possibilities in the field of photosensors, as light sources or as electronic components. This collection of review articles provides a systematic and in-depth overview of the topic, on both a high and current level. It offers information on the physical basics as well as the latest results in a compact yet comprehensive manner. The contributions cover the physical processes involved in manufacture, from semiconductor growth, via their atomic structures and the related characteristics right up to future industrial applications. A highly pertinent book for anyone working in applied materials research or the semiconductor industry.

This timely monograph addresses an important class of semiconductors and devices that constitute the underlying technology for blue lasers. It succinctly treats structural, electrical and optical properties of nitrides and the substrates on which they are deposited, band structures of nitrides, optical processes, deposition and fabrication technologies, light-emitting diodes, and lasers. It also includes many tables and figures detailing the properties and performance of nitride semiconductors and devices.