Preface

This book provides a unified treatment of the many phenomena encountered in the operation of modern MOS transistors and shows how such phenomena can be modeled analytically. The book is mainly written for use in a senior or first-year graduate course. It is felt that electrical engineering students have much to gain from a course devoted to the subject. The MOS transistor is the dominant VLSI device. A course devoted to it is invaluable to those planning a career in device physics and modeling. For such people, the standard courses on semiconductor devices usually cover too many different devices to do justice to any one of them and do not present the intricacies and trade-offs involved in a detailed modeling effort. A course devoted to the MOS transistor is also extremely valuable for those who want to use the device to design state-of-the-art circuits. Integrated circuit designers have the opportunity to select devices to meet circuit needs, and they can do this most intelligently if they really understand the workings of the devices. One can, of course, design systems by using predesigned circuit building blocks as black boxes, if truly high performance is not important. But when state-of-the-art performance is a must, one has to consider device details. In addition, a deep knowledge of device operation and modeling is needed for understanding the computer simulator models a designer is working with, and for identifying their limitations. Many circuit designers in the industry spend endless hours trying to interpret strange circuit simulation results, not realizing that these are largely due to modeling inadequacies. Without adequate device understanding, valuable time and effort is likely to be wasted on overdesign, brute-force approaches, and design iterations. These authors believe that no integrated circuit designer's education is complete without detailed exposure to MOS transistor operation and modeling.

In the decade that has passed since the publication of the second edition of this book, there have been significant advances in the understanding and modeling of the MOS transistor. In addition, the requirements for modeling this device on the part of the circuit design community are now much more demanding. For example, the push for ever-smaller dimensions has revealed phenomena previously ignored. In addition, industrial surface potential–based models are now a reality. Thus, the book has been extensively revised, as discussed in the description of the individual chapters below. To give the reader an idea of the extent of the revisions, suffice it to say that, although there are now two coauthors, each has labored more than the first author did when he revised the first edition!