Step One: Design

The circuit is designed using computer modeling techniques. A structural description of the design is developed from the given electrical specifications. After the circuit has been designed, the design is verified using computer simulation to test functionality and to develop and test layouts of the circuit path. The layout phase identifies the location of the circuits on the silicon surface and their interconnections. Computer simulation analyzes the completed layout to verify complex geometrical constraints. The designers develop a set of mask descriptions when the layout is complete. A prototype chip is manufactured and returned to the designers for extensive testing, including diagnostic testing in which actual performance is compared with design expectations.

Step Two: Wafer Production

A wafer is a thin, round slice of a semiconductor material, usually silicon. In wafer production, purified polycrystalline silicon, created from sand, is heated to a molten liquid. A small piece of solid silicon (seed) is placed on the molten liquid. As the seed is slowly pulled from the melt, the surface tension between the seed and molten silicon causes a small amount of the liquid to rise with the seed and cool. The resulting crystal ingot is then ground to a uniform diameter and a diamond saw blade cuts the ingot into thin wafers. The wafer is processed through a