TABLE OF CONTENTS Charles J. Alpert, Dinesh P. Mehta, and Sachin S. Sapatnekar
The purpose of VLSI physical design is to embed an abstract circuit description, such as a netlist, into silicon, creating a detailed geometric layout on a die. In the early years of semiconductor technology, the task of laying out gates and interconnect wires was carried out manually (i.e., by hand on graph paper, or later through the use of layout editors). However, as semiconductor fabrication processes improved, making it possible to incorporate large numbers of transistors onto a single chip (a trend that is well captured by Moore s law), it became imperative for the design community to turn to the use of automation to address the resulting problem of scale. Automation was facilitated by the improvement in the speed of computers that would be used to create the next generation of computer chips resulting in their own replacement! The importance of automation was reflected in the scientific community by the formation of the Design Automation Conference in 1963 and both the International Conference on Computer-Aided Design and the IEEE Transactions on Computer-Aided Design in 1983; today, there are several other conferences and journals on design automation.
While the problems of scale have been one motivator for automation, other factors have also come into play. Most notably, improvements in technology have resulted in the invalidation of some critical...
