This book is concerned with wafer fabrication and the factories that manufacture microprocessors and other integrated circuits. With the invention of the transistor in 1947, the world as we knew it changed. The transistor led to the microprocessor, and the microprocessor, the guts of the modern computer, has created an epoch of virtually unlimited information processing. The electronics and computer revolution has brought about, for better or worse, a new way of life. This revolution could not have occurred without wafer fabrication, and its associated processing technologies. A microprocessor is fabricated via a lengthy, highly-complex sequence of chemical processes. The success of modern chip manufacturing is a miracle of technology and a tribute to the hundreds of engineers who have contributed to its development. This book will delineate the magnitude of the accomplishment, and present methods to analyze and predict the performance of the factories that make the chips. The set of topics covered juxtaposes several disciplines of engineering. A primary subject is the chemical engineering aspects of the electronics industry, an industry typically thought to be strictly an electrical engineer's playground. The book also delves into issues of manufacturing, operations performance, economics, and the dynamics of material movement, topics often considered the domain of industrial engineering and operations research. Hopefully, we have provided in this work a comprehensive treatment of both the technology and the factories of wafer fabrication. Novel features of these factories include long process flows and a dominance of processing over operational issues.