Conclusions

This book has presented an attempt at a comprehensive treatment of topics related to the emerging disciplines of design for manufacturability and statistical design. The central premise of the book is that the variability must be rigorously described as either random or systematic before meaningful measures can be taken to mitigate its impact on design procedures. This requires the understanding of the physical causes of variability in advanced semiconductor processes, techniques for measuring the relevant characteristics of data, and for describing the results of experiments in a rigorous language of statistics. Once the patterns of variability affecting a specific process module are understood, corrective measures can be taken. If the variability is systematic, that is, it can be traced to a clear functional dependency, such as the featureto- feature spacing or wire density, then it can be modeled in the design flow and its impact on design precisely accounted for. If the variability is random, then statistical or worst-case techniques must be used to deal with it.

The topics covered by each chapter of this book are complex enough to each deserve a book. It is unfortunately impossible to do full justice to every concept discussed in the book. Our intent was to provide the foundation for a rigorous study of variability and its impact on the design process. We want to conclude by identifying the additional resources that the readers could use to further investigate the questions discussed in the book.