Physics, Fabrication, and Applications of Multilayered Structures


Book Description

Low-dimensional materials are of fundamental interest in physics and chemistry and have also found a wide variety of technological applica tions in fields ranging from microelectronics to optics. Since 1986, several seminars and summer schools devoted to low-dimensional systems have been supported by NATO. The present one, Physics, Fabrication and Applications of Multilayered structures, brought together specialists from different fields in order to review fabrication techniques, charac terization methods, physics and applications. Artificially layered materials are attractive because alternately layering two (or more) elements, by evaporation or sputtering, is a way to obtain new materials with (hopefully) new physical properties that pure materials or alloys do not allow. These new possibilities can be ob tained in electronic transport, optics, magnetism or the reflectivity of x-rays and slow neutrons. By changing the components and the thickness of the layers one can track continuously how the new properties appear and follow the importance of the multilayer structure of the materials. In addition, with their large number of interfaces the study of inter face properties becomes easier in multilayered structures than in mono layers or bilayers. As a rule, the role of the interface quality, and also the coupling between layers, increases as the thickness of the layer decreases. Several applications at the development stage require layer thicknesses of just a few atomic layers.




The Physics of Submicron Semiconductor Devices


Book Description

The papers contained in the volume represent lectures delivered as a 1983 NATO ASI, held at Urbino, Italy. The lecture series was designed to identify the key submicron and ultrasubmicron device physics, transport, materials and contact issues. Nonequilibrium transport, quantum transport, interfacial and size constraints issues were also highlighted. The ASI was supported by NATO and the European Research Office. H. L. Grubin D. K. Ferry C. Jacoboni v CONTENTS MODELLING OF SUB-MICRON DEVICES.................. .......... 1 E. Constant BOLTZMANN TRANSPORT EQUATION... ... ...... .................... 33 K. Hess TRANSPORT AND MATERIAL CONSIDERATIONS FOR SUBMICRON DEVICES. . .. . . . . .. . . . .. . .. . .... ... .. . . . .. . . . .. . . . . . . . . . . 45 H. L. Grubin EPITAXIAL GROWTH FOR SUB MICRON STRUCTURES.................. 179 C. E. C. Wood INSULATOR/SEMICONDUCTOR INTERFACES.......................... 195 C. W. Wilms en THEORY OF THE ELECTRONIC STRUCTURE OF SEMICONDUCTOR SURFACES AND INTERFACES......................................... 223 C. Calandra DEEP LEVELS AT COMPOUND-SEMICONDUCTOR INTERFACES........... 253 W. Monch ENSEMBLE MONTE CARLO TECHNIqUES............................. 289 C. Jacoboni NOISE AND DIFFUSION IN SUBMICRON STRUCTURES................. 323 L. Reggiani SUPERLATTICES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 . . . . . . . . . . . . K. Hess SUBMICRON LITHOGRAPHY 373 C. D. W. Wilkinson and S. P. Beaumont QUANTUM EFFECTS IN DEVICE STRUCTURES DUE TO SUBMICRON CONFINEMENT IN ONE DIMENSION.... ....................... 401 B. D. McCombe vii viii CONTENTS PHYSICS OF HETEROSTRUCTURES AND HETEROSTRUCTURE DEVICES..... 445 P. J. Price CORRELATION EFFECTS IN SHORT TIME, NONS TAT I ONARY TRANSPORT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477 . . . . . . . . . . . . J. J. Niez DEVICE-DEVICE INTERACTIONS............ ...................... 503 D. K. Ferry QUANTUM TRANSPORT AND THE WIGNER FUNCTION................... 521 G. J. Iafrate FAR INFRARED MEASUREMENTS OF VELOCITY OVERSHOOT AND HOT ELECTRON DYNAMICS IN SEMICONDUCTOR DEVICES............. 577 S. J. Allen, Jr.




Ultrathin Magnetic Structures II


Book Description

The ability to understand and control the unique properties of interfaces has created an entirely new field of magnetism, with profound impact in technology and serving as the basis for a revolution in electronics. Our understanding of the physics of magnetic nanostructures has also advanced significantly. This rapid development has generated a need for a comprehensive treatment that can serve as an introduction to the field for those entering it from diverse fields, but which will also serve as a timely overview for those already working in this area. The four-volume work Ultra-Thin Magnetic Structures aims to fulfill this dual need. The original two volumes – now available once more – are "An Introduction to the Electronic, Magnetic and Structural Properties" (Vol. I) and Measurement Techniques and Novel Magnetic Properties (this volume). Two new volumes, "Fundamentals of Nanomagnetism" and "Applications of Nanomagnetism," extend and complete this comprehensive work by presenting the foundations of spintronics.










Science and Engineering of One- and Zero-Dimensional Semiconductors


Book Description

This volume comprises the proceedings of the NATO Advanced Research Workshop on the Science and Engineering of 1- and O-dimensional semiconductors held at the University of Cadiz from 29th March to 1st April 1989, under the auspices of the NATO International Scientific Exchange Program. There is a wealth of scientific activity on the properties of two-dimensional semiconductors arising largely from the ease with which such structures can now be grown by precision epitaxy techniques or created by inversion at the silicon-silicon dioxide interface. Only recently, however, has there burgeoned an interest in the properties of structures in which carriers are further confined with only one or, in the extreme, zero degrees of freedom. This workshop was one of the first meetings to concentrate almost exclusively on this subject: that the attendance of some forty researchers only represented the community of researchers in the field testifies to its rapid expansion, which has arisen from the increasing availability of technologies for fabricating structures with small enough (sub - O. I/tm) dimensions. Part I of this volume is a short section on important topics in nanofabrication. It should not be assumed from the brevity of this section that there is little new to be said on this issue: rather that to have done justice to it would have diverted attention from the main purpose of the meeting which was to highlight experimental and theoretical research on the structures themselves.




Science and Technology of Fast Ion Conductors


Book Description

The rediscovery of fast ion conduction in solids in the 1960's stimulated interest both in the scientific community in which the fundamentals of diffusion, order-disorder phenomena and crystal structure evaluation required re-examination, and in the technical community in which novel approaches to energy conversion and chemical sensing became possible with the introduction of the new field of "Solid State Ionics. " Because of both the novelty and the vitality of this field, it has grown rapidly in many directions. This growth has included the discovery of many new crystalline fast ion conductors, and the extension to the fields of organic and amorphous compounds. The growth has involved the extension of classical diffusion theory in an attempt to account for carrier interactions and the development of sophisticated computer models. Diffraction techniques have been refined to detect carrier distributions and anharmonic vibrations. Similar advances in the application of other techniques such as NMR, Raman, IR, and Impedance Spectroscopies to this field have also occurred. The applications of fast ion conducting solid electrolytes have also developed in many directions. High energy density Na/S batteries are now reaching the last stages of development, Li batteries are being implanted in humans for heart pacemakers, and solid state fuel cells are again being considered for future power plants. The proliferation of inexpensive microcomputers has stimulated the need for improved chemical sensors--a major application now being the zirconia auto exhaust sensor being sold by the millions each year.




Polaritons in Periodic and Quasiperiodic Structures


Book Description

In recent years there have been exciting developments in techniques for producing multilayered structures of different materials, often with thicknesses as small as only a few atomic layers. These artificial structures, known as superlattices, can either be grown with the layers stacked in an alternating fashion (the periodic case) or according to some other well-defined mathematical rule (the quasiperiodic case). This book describes research on the excitations (or wave-like behavior) of these materials, with emphasis on how the material properties are coupled to photons (the quanta of the light or the electromagnetic radiation) to produce "mixed waves called polaritons.·Clear and comprehensive account of polaritons in multilayered structures·Covers both periodic and quasiperiodic superlattices·Careful attention to theoretical developments and tools·Invaluable guide for researchers in this field·Shows developments from the basics to advanced topics




Low-dimensional Semiconductors


Book Description

This text is a first attempt to pull together the whole of semiconductor science and technology since 1970 in so far as semiconductor multilayers are concerned. Material, technology, physics and device issues are described with approximately equal emphasis, and form a single coherant point of view. The subject matter is the concern of over half of today's active semiconductor scientists and technologists, the remainder working on bulk semiconductors and devices. It is now routine to design and the prepare semiconductor multilayers at a time, with independent control over the dropping and composition in each layer. In turn these multilayers can be patterned with features that as a small as a few atomic layers in lateral extent. The resulting structures open up many new ares of exciting solid state and quantum physics. They have also led to whole new generations of electronic and optoelectronic devices whose superior performance relates back to the multilayer structures. The principles established in the field have several decades to go, advancing towards the ultimate of materials engineering, the design and preparation of solids atom by atom. The book should appeal equally to physicists, electronic engineers and materials scientists.




Growth and Optical Properties of Wide-Gap II–VI Low-Dimensional Semiconductors


Book Description

This volume contains the Proceedings of the NATO Advanced Research Workshop on "Growth and Optical Properties of Wide Gap II-VI Low Dimensional Semiconductors", held from 2 - 6 August 1988 in Regensburg, Federal Republic of Germany, under the auspices of the NATO International Scientific Exchange Programme. Semiconducting compounds formed by combining an element from column II of the periodic table with an element from column VI (so called II-VI Semiconductors) have long promised many optoelectronic devices operating in the visible region of the spectrum. However, these materials have encountered numerous problems including: large number of defects and difficulties in obtaining p- and n-type doping. Advances in new methods of material preparation may hold the key to unlocking the unfulfilled promises. During the workshop a full session was taken up covering the prospects for wide-gap II-VI Semiconductor devices, particularly light emitting ones. The growth of bulk materials was reviewed with the view of considering II-VI substrates for the novel epitaxial techniques such as MOCVD, MBE, ALE, MOMBE and ALE-MBE. The controlled introduction of impurities during non-equilibrium growth to provide control of the doping type and conductivity was emphasized.