Perspectives on scaling theory and CMOS technology - understanding the past, present, and future

The critical importance of scaling theory to the success of CMOS technology is reviewed and evaluated. The history of CMOS shows that scaling theory has been the dominant theme, but that the evolution of the technology has followed different directions at different times due to constraints imposed by scaling theory. The state of present-day constraints is considered, followed by discussion of some possible options for continuing the progress of CMOS into the future.