Physics Of Submicron Devices

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.

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.

The aim of this book is to resolve the problem of electron and hole transport with a coherent and consistent theory that is relevant to the understanding of transport phenomena in submicron devices. Along the road, readers encounter landmarks in theoretical physics as the authors guide them through the strong and weak aspects of various hypotheses.

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.