Defects And Properties Of Semiconductors

Covering topics that are especially important in electronic device development, this book surveys the properties, effects, roles and characterization of structurally extended defects in semiconductors. The basic properties of extended defects are outlined, and their effect on the electronic properties of semiconductors, their role in semiconductor devices, and techniques for their characterization are discussed. This text is suitable for advanced undergraduate and graduate students in materials science and engineering, and for those studying semiconductor physics.

This volume contains nearly all of the papers presented at the Symposium on "Defects and Qualities of Semiconductors" which was held in Tokyo on May 17-18, 1984, under the sponsorship of the SOCIETY OF NON-TRADITIONAL TECHNOLOGY. The Symposium was organized by the promoting committee of the research project "Quality Developement of Semiconductors by Utilization of Crystal Defects" sponsored by the Science and Technology Agency of Japan. Defect study in semiconductor engineering started originally with seeking methods how to suppress generation of harmful defects during device processing in order to achieve a high yield of device fabrication. Recently, a new trend has appeared in which crystal defects are positively utilized to improve the device performance and reliability. A typical example is the intrinsic gettering technique for Czochralski silicon. Thus, a new term "DEFECT ENGINEERING" was born. It is becoming more important to control density and distribution of defects than to eliminate all the defects. Very precise and deep knowledge on defects is required to establish such techniques as generation and development of defects desired depending on type of devices and degree of integration. Electrical, optical and mechanical effects of defects should be also understood correctly. Such knowledge is essential even for eliminating defects from some specified device regions. It is the time now to investigate defect properties and defect kinetics in an energetic way. From this point of view, all the speakers in this symposium were invited among the most active investigators in the field of defect engineering in Japan.

Research advances in III-nitride semiconductor materials and device have led to an exponential increase in activity directed towards electronic and optoelectronic applications. There is also great scientific interest in this class of materials because they appear to form the first semiconductor system in which extended defects do not severely affect the optical properties of devices. The volume consists of chapters written by a number of leading researchers in nitride materials and device technology with the emphasis on the dopants incorporations, impurities identifications, defects engineering, defects characterization, ion implantation, irradiation-induced defects, residual stress, structural defects and phonon confinement. This unique volume provides a comprehensive review and introduction of defects and structural properties of GaN and related compounds for newcomers to the field and stimulus to further advances for experienced researchers. Given the current level of interest and research activity directed towards nitride materials and devices, the publication of the volume is particularly timely. Early pioneering work by Pankove and co-workers in the 1970s yielded a metal-insulator-semiconductor GaN light-emitting diode (LED), but the difficulty of producing p-type GaN precluded much further effort. The current level of activity in nitride semiconductors was inspired largely by the results of Akasaki and co-workers and of Nakamura and co-workers in the late 1980s and early 1990s in the development of p-type doping in GaN and the demonstration of nitride-based LEDs at visible wavelengths. These advances were followed by the successful fabrication and commercialization of nitride blue laser diodes by Nakamura et al at Nichia. The chapters contained in this volume constitutes a mere sampling of the broad range of research on nitride semiconductor materials and defect issues currently being pursued in academic, government, and industrial laboratories worldwide.

This book provides an up-to-date review of the experimental and theoretical methods used for studying defects in semiconductors, this book focuses on recent developments driven by the requirements of new materials, including nitrides, oxide semiconductors and 2-D semiconductors.

Defects in semiconductors have been studied for many years, in many cases with a view toward controlling their behaviour through various forms of “defect engineering”. For example, in the bulk, charging significantly affects the total concentration of defects that are available to mediate phenomena such as solid-state diffusion. Surface defects play an important role in mediating surface mass transport during high temperature processing steps such as epitaxial film deposition, diffusional smoothing in reflow, and nanostructure formation in memory device fabrication. “Charged Defects in Semiconductors” details the current state of knowledge regarding the properties of the ionized defects that can affect the behaviour of advanced transistors, photo-active devices, catalysts, and sensors. Features: group IV, III-V, and oxide semiconductors; intrinsic and extrinsic defects; and, point defects, as well as defect pairs, complexes and clusters.

The systematic study of defects in semiconductors began in the early fifties. FrQm that time on many questions about the defect structure and properties have been an swered, but many others are still a matter of investigation and discussion. Moreover, during these years new problems arose in connection with the identification and char acterization of defects, their role in determining transport and optical properties of semiconductor materials and devices, as well as from the technology of the ever in creasing scale of integration. This book presents to the reader a view into both basic concepts of defect physics and recent developments of high resolution experimental techniques. The book does not aim at an exhaustive presentation of modern defect physics; rather it gathers a number of topics which represent the present-time research in this field. The volume collects the contributions to the Advanced Research Workshop "Point, Extended and Surface Defects in Semiconductors" held at the Ettore Majo rana Centre at Erice (Italy) from 2 to 7 November 1988, in the framework of the International School of Materials Science and Technology. The workshop has brought together scientists from thirteen countries. Most participants are currently working on defect problems in either silicon submicron technology or in quantum wells and superlattices, where point defects, dislocations, interfaces and surfaces are closely packed together.

This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoretical paths. Expert contributors Reviews of the most important recent literature Clear illustrations A broad view, including examination of defects in different semiconductors

From its early beginning before the war, the field of semiconductors has developped as a classical example where the standard approximations of 'band theory' can be safely used to study its interesting electronic properties. Thus in these covalent crystals, the electronic structure is only weakly coupled with the atomic vibrations; one-electron Bloch functions can be used and their energy bands can be accurately computed in the neighborhood of the energy gap between the valence and conduction bands; nand p doping can be obtained by introducing substitutional impurities which only introduce shallow donors and acceptors and can be studied by an effective-mass weak-scattering description. Yet, even at the beginning, it was known from luminescence studies that these simple concepts failed to describe the various 'deep levels' introduced near the middle of the energy gap by strong localized imperfections. These imperfections not only include some interstitial and many substitutional atoms, but also 'broken bonds' associated with surfaces and interfaces, dis location cores and 'vacancies', i.e., vacant iattice sites in the crystal. In all these cases, the electronic structure can be strongly correlated with the details of the atomic structure and the atomic motion. Because these 'deep levels' are strongly localised, electron-electron correlations can also playa significant role, and any weak perturbation treatment from the perfect crystal structure obviously fails. Thus, approximate 'strong coupling' techniques must often be used, in line' with a more chemical de scription of bonding.