Heterostructures on Silicon: One Step Further with Silicon


Book Description

In the field of logic circuits in microelectronics, the leadership of silicon is now strongly established due to the achievement of its technology. Near unity yield of one million transistor chips on very large wafers (6 inches today, 8 inches tomorrow) are currently accomplished in industry. The superiority of silicon over other material can be summarized as follow: - The Si/Si0 interface is the most perfect passivating interface ever 2 obtained (less than 10" e y-I cm2 interface state density) - Silicon has a large thermal conductivity so that large crystals can be pulled. - Silicon is a hard material so that large wafers can be handled safely. - Silicon is thermally stable up to 1100°C so that numerous metallurgical operations (oxydation, diffusion, annealing ... ) can be achieved safely. - There is profusion of silicon on earth so that the base silicon wafer is cheap. Unfortunatly, there are fundamental limits that cannot be overcome in silicon due to material properties: laser action, infra-red detection, high mobility for instance. The development of new technologies of deposition and growth has opened new possibilities for silicon based structures. The well known properties of silicon can now be extended and properly used in mixed structures for areas such as opto-electronics, high-speed devices. This has been pioneered by the integration of a GaAs light emitting diode on a silicon based structure by an MIT group in 1985.




Semiconductors and Semimetals


Book Description

Semiconductors and Semimetals




Electrodynamics of Solids and Microwave Superconductivity


Book Description

This book presents the interdisciplinary field of solid electrodynamics and its applications in superconductor and microwave technologies. It gives scientists and engineers the foundation necessary to deal with theoretical and applied electromagnetics, continuum mechanics, applied superconductivity, high-speed electronic circuit design, microwave engineering and transducer technology.




Surface Processing and Laser Assisted Chemistry


Book Description

The papers in this volume cover all aspects of laser assisted surface processing ranging from the preparation of high-Tc superconducting layer structures to industrial laser applications for device fabrication. The topics presented give recent results in organometallic chemistry and laser photochemistry, and novel surface characterization techniques. The ability to control the surface morphology by digital deposition and etching shows one of the future directions for exciting applications of laser surface processing, some of which may apply UV and VUV excitation. The understanding of elementary proceses is essential for the design of novel deposition methods, with diamond CVD being an outstanding example. The high quality of these contributions once again demonstrates that the E-MRS is an efficient forum for interaction between research workers and industry.




The New Superconducting Electronics


Book Description

This volume is based on the proceedings of the NATO-sponsored Advanced Studies Institute (ASn on The New Superconducting Electronics (held 9-20 August 1992 in Waterville Valley, New Hampshire USA). The contents herein are intended to provide an update to an earlier volume on the same subject (based on a NATO ASI held in 1988). Four years seems a relatively short time interval, and our title itself, featuring The New Superconducting Electronics, may appear somewhat pretentious. Nevertheless, we feel strongly that the ASI fostered a timely reexamination of the technical progress and application potential of this rapid-paced field. There are, indeed, many new avenues for technological innovation which were not envisioned or considered possible four years ago. The greatest advances by far have occurred with regard to oxide superconductors, the so-called high transition-temperature superconductors, known in short as HTS. These advances are mainly in the ability to fabricate both (1) high-quality, relatively large-area films for microwave filters and (2) multilayer device structures, principally superconducting-normal-superconducting (SNS) Josephson junctions, for superconducting-quantum-interference-device (SQUID) magnetometers. Additionally, we have seen the invention and development of the flux-flow transistor, a planar three-terminal device. During the earlier ASI only the very first HTS films with adequate critical-current density had just been fabricated, and these were of limited area and had high resistance for microwave current.




Beam Processing and Laser Chemistry


Book Description

This volume discusses both the practical and theoretical aspects of energy beam materials processing. It highlights the recent advances in the use of beams and incoherent light sources to enhance or modify chemical processes at solid surfaces. Special attention is given to the latest developments in the use of ion, electron and photon beams, and on laser-assisted process chemistry. Thin film and surface and interface reactions as well as bulk phase transformations are discussed. Practical technological details and the criteria for present and future applications are also reviewed. The papers collected in this volume reflect the continuing strong interest and variety of development in this field.




High-Temperature Superconducting Materials Science and Engineering


Book Description

This book explores the fascinating field of high-temperature superconductivity. Basic concepts–including experimental techniques and theoretical issues–are discussed in a clear, systematic manner. In addition, the most recent research results in the measurements, materials synthesis and processing, and characterization of physical properties of high-temperature superconductors are presented. Researchers and students alike can use this book as a comprehensive introduction not only to superconductivity but also to materials-related research in electromagnetic ceramics. Special features of the book: - presents recent developments in vortex-state properties, defects characterization, and phase equilibrium - introduces basic concepts for experimental techniques at low temperatures and high magnetic fields - provides a valuable reference for materials-related research - discusses potential industrial applications of high-temperature superconductivity - includes novel processing technologies for thin film and bulk materials - suggests areas of research and specific problems whose solution can make high-Tc superconductors a practical reality




Germanium-silicon Strained Layers and Heterostructures


Book Description

Biaxial strain in coherent GeSi layers grown on Si substrates provides a powerful tool for tailoring bandgaps and band offsets. Extremely high electron and hole mobilities have been obtained in modulation-doped GeSi strained layer heterostructures. Ultra-high-speed Heterojunction Bipolar Transistors and MODFETs, and long wavelength (1 to 20 micrometre) IR Detectors have been fabricated using these layers. Quantum wells, ultra-thin period superlattices, and quantum dots can also be fabricated using the strained layers. These devices were previously implemented using III-V semiconductors. Now they can be fabricated using existing Si technology, which is mature and reliable. GeSi strained layer technology has made it possible to manufacture monolithic Si integrated circuits containing heterojunction devices.




Physics and Technology of Amorphous-Crystalline Heterostructure Silicon Solar Cells


Book Description

Today’s solar cell multi-GW market is dominated by crystalline silicon (c-Si) wafer technology, however new cell concepts are entering the market. One very promising solar cell design to answer these needs is the silicon hetero-junction solar cell, of which the emitter and back surface field are basically produced by a low temperature growth of ultra-thin layers of amorphous silicon. In this design, amorphous silicon (a-Si:H) constitutes both „emitter“ and „base-contact/back surface field“ on both sides of a thin crystalline silicon wafer-base (c-Si) where the electrons and holes are photogenerated; at the same time, a-Si:H passivates the c-Si surface. Recently, cell efficiencies above 23% have been demonstrated for such solar cells. In this book, the editors present an overview of the state-of-the-art in physics and technology of amorphous-crystalline heterostructure silicon solar cells. The heterojunction concept is introduced, processes and resulting properties of the materials used in the cell and their heterointerfaces are discussed and characterization techniques and simulation tools are presented.




Superconducting Electronics


Book Description

The genesis of the NATO Advanced Study Institute (ASI) upon which this volume is based, occurred during the summer of 1986 when we came to the realization that there had been significant progress during the early 1980's in the field of superconducting electronics and in applications of this technology. Despite this progress, there was a perception among many engineers and scientists that, with the possible exception of a limited number of esoteric fundamental studies and applications (e.g., the Josephson voltage standard or the SQUID magnetometer), there was no significant future for electronic systems incorporating superconducting elements. One of the major reasons for this perception was the aversion to handling liquid helium or including a closed-cycle helium liquefier. In addition, many critics felt that IBM's cancellation of its superconducting computer project in 1983 was "proof" that superconductors could not possibly compete with semiconductors in high-speed signal processing. From our perspective, the need for liquid helium was outweighed by improved performance, i. e., higher speed, lower noise, greater sensitivity and much lower power dissipation. For many commercial, medical, scientific and military applications, these attributes can lead to either enhanced capability (e.g., compact real-time signal processing) or measurements that cannot be made using any other technology (e.g., SQUID magnetometry to detect neuromagnetic activity).