A question sometimes posed to researchers in silicon is: Why are you still working on silicon? How much more do we need to learn? Not only is Si a relatively simple element, it is one of the most common in the earth's crust. This element has been very extensively studied. One reason we keep studying silicon is because it is not just an element, it is also an industry. The microelectronics business has a massive economic impact on our lives. From cars to washing machines, almost all consumer goods contain silicon microprocessors in some form. Our daily lives depend on the stuff. Figure 1 shows the predominance of Si in a breakdown of the microelectronics industry. In 1994 microelectronics has been a $1 × 1011-per year industry worldwide, and it is still growing rapidly. CMOS, or complementary metal-oxide-semiconductor transistors, dominate this business, some being bipolar. The entire compound semiconductor industry is a small part of this picture, composing 2% of the business (although $2 billion is not bad for a “niche” market). The $100 billion business built around silicon makes it the most important element in world economics, although there is some evidence that C and O may also be important for the support of our daily lives. One thing, however, is clear-the economic need to understand silicon and everything it does is tremendous.