SILICON PROCESSING FOR THE VLSI ERA is a Series of texts designed to provide a comprehensive and up-to-date treatment of this rapidly changing field.

This Series will consist of four volumes, of which this book is the second, subtitled, subtitled Process Integration - Volume 1, subtitled Process Technology, was published in 1986 (and in its 2nd Edition, in 2000). Volume 3, subtitled The Submicron MOSFET was published in 1995, and Volume 4, subtitled Deep-Submicron Process Technology, in 2002.

In this title, we explain how the individual processes described in Volume 1 are combined to produce silicon integrated circuits. This task is referred to as Process Integration.

The first part of the book deals with sub-process integration: that is, the effort involved in forming circuit structures that can be implemented into a variety of circuit types. These structures include isolation structures (Chapter 2), metal-silicon contacts (Chapter 3), and device-interconnect structures (Chapter 4).

The second part of the book covers the process integration tasks of full-device-type technologies, including NMOS (Chapter 5), CMOS (Chapter 6), bipolar (Chapter 7) and semiconductor memories (Chapter 8). Chapter 9 describes the process simulation tools that are available for aiding the process integration and development efforts.

The purpose of writing this text is to provide professionals involved in the microelectronics industry with a single source that provides a complete overview of the technology associated with the manufacture of silicon integrated circuits. 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 contributes 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 unevenness in 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 the information is presented without defining each technical “buzzword” as it is first introduced.

In our books such drawbacks are avoided by treating the subject of VLSI fabrication from a unified and more pedagogical viewpoint, and by carefully defining technical terms when they are first introduced. The result is intended to be 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 occurred in publishing that has been exploited by the author to create a unique series of books on silicon processing. That is, electronic publishing techniques can cut the time required to produce a published book from a finished manuscript.

This task has traditionally taken 15-18 months, but can now reduced to less than 3 months. If such conventional techniques are used to produce books in such fast-breaking fields as VLSI fabrication, these books automatically posses a built-in obsolescence, even upon being first published.

We have taken advantage of these rapid production techniques, and have been able to successfully meet the reduced production-time schedule. As a result, information contained in technical journals and conferences which was available within three months of the book’s publication date has been included.

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 on the subject, or who are new to the field, will find it invaluable. Integrated-circuit designers, test engineers, and integrated-circuit equipment designers, 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 a very suitable text for graduate-level courses on silicon processing techniques, offered to students of electrical engineering, applied physics, and materials science. It is assumed that such students already possess a basic familiarity with semiconductor device physics.

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 is an outgrowth of several extensive seminars conducted by the author through the Engineering Extension of the University of California, Berkeley. Over two thousand engineers and managers from more than 75 companies and government agencies have enrolled in these short courses since they were first offered in 1984.

A book of this length and diversity would not have been possible without the indirect and direct assistance of many other workers. To begin, virtually all of the information presented in this text is based on the research efforts of 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 author expresses heartfelt thanks to those who gave of their time, effort, and intellect.

Each of the chapters was reviewed after the writing was completed. The engineers and scientists who participated in this review were numerous. The main reviewers are listed on the page before the preface, and we would like to thank them once again at this point for their assistance. That is, professionals (each one an expert in the topic covered by the chapter they reviewed), read an entire chapter for technical correctness, and also provided appropriate comments and corrections.

Stanley Wolf Ph.D.