Semiconductors are materials having conductivity between that of conductors (metals) and insulators (ceramics). Semiconductors are being widely used in almost all microprocessor chips and transistors. It can be said that anything, which is computerized or uses radio waves, has semiconductors at the heart of its functioning. Generally all the semiconductor chips are created with silicon, that is why expressions like "silicon valley" and "silicon economy" have become so popular. Semiconductors can be classified as pure and impure semiconductors. Pure semiconductors include elements like silicon, germanium, gallium arsenide or cadmium selenide. Pure semiconductors can be converted into impure ones through the process of doping in which impurities are added to pure elements in order to bring changes in the conductivity of the materials.

The global semiconductor equipment bookings touched US$10.22 billion in the year 2007 and the semiconductor manufacturing equipment bills were worth US$11.06 billion in the same year. Thus we can say that the semiconductor industry is one of the most profit making industries in the world. The largest semiconductor manufacturing nation is China with a whopping 70% share in manufacturing, followed by USA with 10% share. Singapore, Russia and Taiwan are other leading semiconductor manufacturers. The global market for semiconductors grew at the rate of 18% and reached US$36.6 billion in the year 2006. According to an estimate by SEMI, it will reach US$40.7 billion in 2007.