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.

The purposes of this book are many. First, we must point out that it is not a device book, as a proper treatment of the range of important devices would require a much larger volume even without treating the important physics for submicron devices. Rather, the book is written principally to pull together and present in a single place, and in a (hopefully) uniform treatment, much of the understanding on relevant physics for submicron devices. Indeed, the understand ing that we are trying to convey through this work has existed in the literature for quite some time, but has not been brought to the full attention of those whose business is the making of submicron devices. It should be remarked that much of the important physics that is discussed here may not be found readily in devices at the 1.0-JLm level, but will be found to be dominant at the O.I-JLm level. The range between these two is rapidly being covered as technology moves from the 256K RAM to the 16M RAM chips.

Nanoscale Science, whose birth and further growth and development has been driven by the needs of the microelectronics industry on one hand, and by the sheer human curiosity on the other hand, has given researchers an unprecedented capability to design and construct devices whose function ality is based on quantum and mesoscopic effects. A necessary step in this process has been the development of reliable fabrication techniques in the nanometer scale: two-dimensional systems, quantum wires and dots, and Coulomb blockade structures with almost ideal properties can nowadays be fabricated, and subjected to experimental studies. How does one fabricate micro/nanostructures of low dimensionality? How does one perform a nanoscale characterization of these structures? What are the fundamental properties typical to the structures? Which new physical processes in nanostructures need to be understood? What new physical processes may allow us to create new nanostructures? An improved understanding of these topics is necessary for creation of new concepts for future electronic and optoelectronic devices and for characterizing device structures based on those concepts.

Research on electronic transport in ultra small dimensions has been highly stimulated by the sensational developments in silicon technology and very large scale integration. The papers in this volume, however, have been influenced to no lesser extent by the advent of molecular beam epitaxy and metal/organic chemical vapor deposition which has made possible the control of semiconductor boundaries on a quantum level. This new control of boundary condi tions in ultra small electronic research is the mathematical reason for a whole set of innovative ideas. For the first time in the history of semiconductors, it is possible to design device functions from physical considerations involving ~ngstom scale dimensions. At the time the meeting was held, July 1982, it was one of the first strong signals of the powerful developments in this area. During the meeting, important questions have been answered concerning ballistic transport, Monte Carlo simulations of high field transport and other developments pertinent to new device concepts and the understanding of small devices from physics to function. The committee members want to express their deep appreciation to the speakers who have made the meeting a success. The USER pro ject of DOD has been a vital stimulous and thanks go to the Army Research Office and the Office of Naval Research for financial sup port. Urbana, January 1984 K. Hess, Conference Chairman J. R. Brews L. R. Cooper, Ex Officio D. K. Ferry H. L. Grubin G. J. Iafrate M. I. Nathan A. F.

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.

Contributed papers of the workshop held at IIT, Madras, in 2003.

The advent of the microelectronics technology has made ever-increasing numbers of small devices on a same chip. The rapid emergence of ultra-large-scaled-integrated (ULSI) technology has moved device dimension into the sub-quarter-micron regime and put more than 10 million transistors on a single chip. While traditional closed-form analytical models furnish useful intuition into how semiconductor devices behave, they no longer provide consistently accurate results for all modes of operation of these very small devices. The reason is that, in such devices, various physical mechanisms affect the device performance in a complex manner, and the conventional assumptions (i. e. , one-dimensional treatment, low-level injection, quasi-static approximation, etc. ) em ployed in developing analytical models become questionable. Thus, the use of numerical device simulation becomes important in device modeling. Researchers and engineers will rely even more on device simulation for device design and analysis in the future. This book provides comprehensive coverage of device simulation and analysis for various modem semiconductor devices. It will serve as a reference for researchers, engineers, and students who require in-depth, up-to-date information and understanding of semiconductor device physics and characteristics. The materials of the book are limited to conventional and mainstream semiconductor devices; photonic devices such as light emitting and laser diodes are not included, nor does the book cover device modeling, device fabrication, and circuit applications.

Fuelled by rapid growth in communications technology, silicon heterostructures and related high-speed semiconductors are spearheading the drive toward smaller, faster and lower power devices. High-Speed Heterostructure Devices is a textbook on modern high-speed semiconductor devices intended for both graduate students and practising engineers. This book is concerned with the underlying physics of heterostructures as well as some of the most recent techniques for modeling and simulating these devices. Emphasis is placed on heterostructure devices of the immediate future such as the MODFET, HBT and RTD. The principles of operation of other devices such as the Bloch Oscillator, RITD, Gunn diode, quantum cascade laser and SOI and LD MOSFETs are also introduced. Initially developed for a graduate course taught at Ohio State University, the book comes with a complete set of homework problems and a web link to MATLAB programs supporting the lecture material.