This book is concerned with the use of Computer-Aided Design (CAD) in the device and process development of Very-Large-Scale-Integrated Circuits (VLSI). The emphasis is in Metal-Oxide-Semiconductor (MOS) technology. State-of-the-art device and process development are presented. This book is intended as a reference for engineers involved in VLSI develop­ ment who have to solve many device and process problems. CAD specialists will also find this book useful since it discusses the organization of the simula­ tion system, and also presents many case studies where the user applies the CAD tools in different situations. This book is also intended as a text or reference for graduate students in the field of integrated circuit fabrication. Major areas of device physics and processing are described and illustrated with Simulations. The material in this book is a result of several years of work on the implemen­ tation of the simulation system, the refinement of physical models in the simulation programs, and the application of the programs to many cases of device developments. The text began as publications in journals and con­ ference proceedings, as weil as lecture notes for a Hewlett-Packard internal CAD course. This book consists of two parts. It begins with an overview of the status of CAD in VLSI, which pointsout why CAD is essential in VLSI development. Part A presents the organization of the two-dimensional simulation system.