The book begins with an historical overview of process control in the semiconductor industry and the reasons why R2R control has emerged as one of the key process control technologies in use in the industry today. The rest of the section traces the evolution of R2R control in the semiconductor industry, including the barriers to its implementation and the enabling technologies that have helped to overcome these barriers, and provides a brief introduction to R2R control and process optimization methods.

The second section of the book focuses on control algorithms and the application of these algorithms to R2R process optimization and control. Particular attention is paid to R2R algorithms based on the exponentially weighted moving average (EWMA) statistic such as the "gradual mode" and the "predictor-corrector" controllers. A significant advantage of these EWMA algorithms is that they are relatively easy to implement and they have been shown to work well for a variety of applications in the semiconductor industry. The rest of the section is devoted to several adaptive algorithms that can be used for both process optimization and control. The last chapter compares the performance of the R2R algorithms discussed in the previous chapters under a variety of conditions for both linear and non-linear processes. It should prove quite helpful to anyone trying to evaluate R2R control strategies.

The third section addresses the role of integration and automation in implementing R2R control in manufacturing environments. These are key enablers for R2R control and, as the authors note, if careful consideration is not given to them when implementing R2R control systems the solutions developed could turn out to be too costly or cumbersome to be useful. Because integration and automation span such a wide domain of technologies and disciplines, standards are absolutely vital to its success. Fortunately the first chapter in this section provides a thorough review of integration and automation standards that have been developed and proposed by organizations like SEMATECH, SEMI, and SIA. The subsequent chapters in this section address specific implementations of R2R control and the integration and automation strategies used with these implementations. A minor criticism of this section is the emphasis in these chapters on the Generic Cell Controller (GCC), although it should be noted that the authors have a wealth of experience with the application of the GCC to R2R control. The remaining sections of the book cover case studies of the application of R2R control to specific semiconductor manufacturing processes like Chemical Mechanical Polishing (CMP) and photolithography and advanced topics such as methods for dealing with process upsets and control strategies that span multiple process technologies. The book concludes with a discussion of the future of R2R control in semiconductor manufacturing and suggestions for further reading which are in addition to the thorough list of references included at the end of each chapter of the book.

In conclusion, this book is a very useful reference for any manufacturing technologist in the semiconductor industry. It provides a good introduction to the basics of R2R control and illustrates its application to semiconductor manufacturing with specific examples and case studies based on the authors personal experiences.


Run-to-Run Control Explained  Dec 20, 2002 By David Drain
Run-to-Run (R2R) control is a process control technique for batch-processing environments in which an algorithm is used to adjust process parameters prior to each batch (run). Information from previous runs, prior process inputs, or environmental information might all play a part in the control algorithm. The authors make a convincing point that run-to-run control has been very successful and has widespread application in the semiconductor industry, and is, in fact, "the least equipment-invasive control scheme that demonstrates real benefit."

This book is not a loose collection of case studies or a group of unrelated articles; it is, rather, a complete and integrated treatment of the subject of run-to-run control in its present state of development. The technical content exhibits the benefit of years of research through [the semiconductor research consortium] Sematech and excellent scholarship with over 300 references included. Both the theory of run-to-run control and the realities of implementation in modern manufacturing environments are covered.

[Excerpted with permission from review to appear in Journal of Quality Technology]