Quantum Well Devices
4.1 Issues in CMOS Device Scaling
4.1.1 MOSFET Scaling Trend
MOSFET scaling has been going on for almost 50 years now. Every three years the average design rule has shrunk to the 70% of the previous generation. Such a rate of shrinkage brings roughly an order of magnitude reduction every 20 years. Starting with a few tens of μm design rules in the 1960s, we already see devices with a physical gate length of a few tens of nanometers in production. In 50 years, some devices have been shrunk down by three orders of magnitude in size (Fig. 4.1).
In early 1990s, people in the United States began their work on a semiconductor technology roadmap (National Technology Roadmap for Semiconductors, Semiconductor Industry Association, ...