This book is devoted to the physics of electron-beam, ion-beam, optical, and x-ray lithography. The need for this book results from the following considerations. The astonishing achievements in microelectronics are in large part connected with successfully applying the relatively new technology of processing (changing the prop erties of) a material into a device whose component dimensions are submicron, called photolithography. In this method the device is imaged as a pattern on a metal film that has been deposited onto a transparent substrate and by means of a broad stream of light is transferred to a semiconductor wafer within which the physical structure of the devices and the integrated circuit connections are formed layer by layer. The smallest dimensions of the device components are limited by the diffraction of the light when the pattern is transferred and are approximately the same as the wavelength of the light. Photolithography by light having a wavelength of A ~ 0.4 flm has made it possible to serially produce integrated circuits having devices whose minimal size is 2-3 flm in the 4 pattern and having 10-105 transistors per circuit.

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.

In this revised and expanded edition, the authors provide a comprehensive overview of the tools, technologies, and physical models needed to understand, build, and analyze microdevices. Students, specialists within the field, and researchers in related fields will appreciate their unified presentation and extensive references.

les Houches This Winter School on "The Physics and Fabrication of Microstructures" originated with a European industrial decision to investigate in some detail the potential of custom-designed microstructures for new devices. Beginning in 1985, GEC and THOMSON started a collaboration on these subjects, supported by an ESPRIT grant from the Commission of the European Com munity. To the outside observer of the whole field, it appears clear that the world effort is very largely based in the United States and Japan. It also appears that cooperation and dissemination of results are very well organised outside Europe and act as a major influence on the development of new concepts and devices. In Japan, a main research programme of the Research and Development for Basic Technology for Future Industries is focused on "Future Electron Devices". In Japan and in the United States, many workshops are organised annually in order to bring together the major specialists in industry and academia, allowing fast dissemination of advances and contacts for setting up cooperative efforts.

VLSI Electronics: Microstructure Science, Volume 7 presents a comprehensive exposition and assessment of the developments and trends in VLSI (Very Large Scale Integration) electronics. This treatise covers subjects that range from microscopic aspects of materials behavior and device performance to the comprehension of VLSI in systems applications. Each chapter is prepared by a recognized authority. The topics contained in this volume include a basic introduction to the application of superconductivity in high-speed digital systems; the expected impact of VLSI technology on the implementation of AI (artificial intelligence); the limits to improvement of silicon integrated circuits; and the various spontaneous noise sources in VLSI circuits and their effect on circuit operation. Scientists, engineers, researchers, device designers, and systems architects will find the book very useful.

The Physical Electronics Department of SRI International (formerly Stanford Research Institute) has been pioneering the development of devices fabricated to submicron tolerances for well over 20 years. In 1961, a landmark paper on electron-beam lithography and its associated technologies was published by K. R. Shoulderst (then at SRI), which set the stage for our subsequent efforts in this field. He had the foresight to believe that the building of such small devices was actually within the range of human capabilities. As a result of this initial momentum, our experience in the technologies associated with microfabrication has become remarkably comprehensive, despite the relatively small size of our research activity. We have frequently been asked to deliver seminars or provide reviews on various aspects of micro fabrication. These activities made us aware of the need for a comprehensive overview of the physics of microfabrication. We hope that this book will fill that need.