Preface to the Silicon Processing Vol. 1 Book

This 2nd Edition of SILICON PROCESSING FOR THE VLSI ERA: Volume 1 - Process Technology (© 2000) follows the 1986 publication of the 1st Edition. More than 20,000 volumes of the 1st Edition were sold, attesting to its widespread acceptance throughout the Microelectronics Community. Professionals and students of this vibrant technology should find our new, 2nd Edition equally useful.

Many new processes and materials have been incorporated into IC fabrication in the 15 years since the 1st Edition was written.

Those are covered in the 2nd Edition, and include: 300-mm Wafers, DUV Lithography, CA-Resists, High-Energy Implantation, HDP-CVD & Etch, Step-&-Scan Aligners, CMP, Dual-Damascene Interconnects, Copper, & Low-k Dielectrics.

Altogether the material of our new book comprises more than 900 pages, 600 illustrations, and 1500 references (with over half of the citations from 1996 to 1999). It also includes those topics from the 1st Edition that are still in use.

The effort of writing and producing this new edition was predominantly carried out by Dr. Stanley Wolf. He revised eight of the 17 Chapters (Chaps. 1, 2, 3, 4, 6, 11, 12, and 14), and entirely wrote the five new ones (Chaps. 5, 13, 15, 16, and 17).

Three of the 17 chapters were revised by Richard N. Tauber (Chaps. 7, 8, and 9), and another by Michael Current (Chap. 10).

Valuable input to Stanley Wolf was also provided by many persons. Foremost of these were R. N. Tauber and C. A. Wolf. Each carefully read the entire manuscript and offered extensive editorial assistance (Tauber: primarily technical, and Wolf: grammatical). Others who provided important technical assistance and critical reviews were: Jerry Healey, Richard Cohen, Chris Mack, Bruce Smith, Robert Simonton, Dennis Hess, Moshe Preil, Wilbur Krussell, Bob Climo, Kathleen Perry, Peter Loewenhardt, and Donald Smith. Roy Montebin, of Vox Mundi, designed the book’s cover.

Stanley Wolf, Ph.D.
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SILICON PROCESSING FOR THE VLSI ERA is a text designed to provide a comprehensive and up-to-date treatment of this important and rapidly changing field. The text consists of three volumes of which this book is the first, subtitled, Process Technology. Volume 2, subtitled Process Integration, was published in 1990. Volume 3, subtitled The Submicron MOSFET, was published in 1995.

In this first volume, the individual processes employed in the fabrication of silicon VLSI circuits are covered in depth (e.g., epitaxial growth, chemical vapor and physical vapor deposition of amorphous and polycrystalline films, thermal oxidation of silicon, diffusion, ion implantation, microlithography, and etching processes).

In addition, chapters are also provided on technical subjects that are common to many of the individual processes, such as vacuum technology, the properties of thin films, and CMOS process integration. The topics covered in the book are listed in more detail in the Table of Contents.

The purpose of writing this text was to provide professionals involved in the microelectronics industry with a single source that offers a complete overview of the technology associated with the manufacture of silicon integrated circuits.

Most other texts on the subject are available only in the form of specialized books (i.e., that treat just a small subset of all of the processes), or in the form of edited volumes (i.e., books in which a group of authors each contribute a small portion of the contents). Such edited volumes typically suffer from a lack of unity in the presented material from chapter-to-chapter, as well as an uneven writing style and level of presentation.

In addition, in multi-disciplinary fields (such as microelectronic fabrication), it is difficult for most readers to follow technical arguments in such books, especially if information is presented without defining technical “buzzwords” when first introduced.

In our book, we hope to overcome such drawbacks by treating the subject of VLSI fabrication from a unified and more pedagogical viewpoint, and by being careful to define technical terms when they are first used. The result is intended to be a user friendly book for workers who have come to the semiconductor industry after having been trained in but one of the many traditional technical disciplines.

An important technical breakthrough has occurred in book publishing that the authors also felt could be exploited in creating a unique book on silicon processing. That is, revolutionary electronic publishing techniques became available in the mid-1980’s, & these can cut the time required to produce a published book from a finished manuscript.

The task traditionally took 15-18 months, but can be now reduced to less than 4 months. If traditional techniques are used to produce books in such fast-breaking fields as VLSI fabrication, these books automatically possess a built-in obsolescence, even upon being first published. The authors took advantage of these rapid production techniques, and were able to successfully meet the reduced production-time schedule.

As a result, it is possible to include information contained in technical journals & conferences within four months of the book's publication date. Most others on silicon processing undergo such 15-18 month production cycles. This is the first such book where such time-delay effects have been eliminated from the production process!

Written for the professional, the book belongs on the shelf of workers in several microelectronic disciplines. Microelectronic fabrication engineers who seek to develop a more complete perspective of the subject, or who are new to the field, will find it invaluable. IC design engineers, test engineers, & semiconductor equipment engineers, who must understand VLSI processing issues to effectively interface with the fabrication environment, will also find it a uniquely useful reference.

The book should also be very suitable as a text for graduate-level courses on silicon processing techniques, offered to students of electrical engineering, applied physics, and materials science. Problems are included at the end of each chapter to assist readers in gauging how well they have assimilated the material in the text.

The book was an outgrowth of Intensive Seminars of the same title as the book, conducted by the authors through the Engineering Extension of the University of California, Berkeley. In the fifteen years that this course has been conducted (1984-1999), several thousand engineers and managers from more than 100 companies have taken it. Its fine reputation is attested to by the fact that many firms have sent participants to subsequent courses, presumably based on the recommendations of earlier participants.

In setting out to create a comprehensive text on VLSI fabrication, the authors each contributed a set of unique and complementary skills to the project.

Professor Stanley Wolf's proficiency as a teacher and writer were utilized to produce a clearly written and logically organized book. Some of this expertise was gained in authoring an earlier best-selling text Electronic Measurements and Laboratory Practice, Prentice-Hall, 1973.

Dr. Richard Tauber brought a technical expertise acquired from his long involvement in the semiconductor industry. He used this background to insure that the most important topics of VLSI fabrication were addressed, and that the information was up-to-date and presented in a technically correct fashion. Note that for over twenty-five years, Dr. Tauber has held positions at Bell Telephone Laboratories, Xerox, Hughes Aircraft Company Microelectronics Research Center, the Microelectronics Center of TRW, and Applied Materials.

The labor of the writing effort was divided between the authors in the following manner: Professor Wolf was responsible for writing Chapters 1, 2, 3, 9, 10, 12, 13, 15, 16, 17, and 18, and Dr. Tauber undertook the writing of Chapters 4, 5, 7, 8, 11, and 14. Material for Chap. 6 was jointly contributed by Andrew R. Coulson and Dr. Tauber.

A book of this length and diversity would not have been possible without the indirect and direct assistance of many other workers. To begin with, virtually all of the information presented in this text is based on the research efforts of a countless number of scientists and engineers. Their contributions are recognized to a small degree by citing some of their articles in the references given at the end of each chapter.

The direct help came in a variety of forms, and was generously provided by many people. The text is a much better work as a result of this aid, and the authors express heartfelt thanks to those who gave of their time, energy, and intellect.

Each of the chapters was reviewed after the writing was completed. The engineers and scientists who participated in this review were numerous. Special thanks are given to Warren Flack, Stephen Franz, Kenneth Tokunaga, and Simon Prussin for their critical reviews. Superlative computer support and access to computer resources was generously made available by Donald E. Carlile, Harry T. Hayes, and Dale Lambertson of the Personal Computer Support Section of the Electronic Systems Group of TRW. Henry Nicholas was a computer expert and friend who lit the fire of inspiration that led to the undertaking of the project. Roy Montibon and Donald Strout of New Archetype Publishing, Inc., Los Angeles, CA designed the cover. Finally, we wish to thank Shirley Rome, Carrol Ann Wolf, and Barbara Tauber for typing the manuscript.

Stanley Wolf and Richard N. Tauber