Silicon crystal growth and epitaxial layer deposition for VLSI devices

Silicon for microelectronic devices is prepared by a complex process that converts polycrystalline material into a single crystal ingot of silicon weighing as much as 40 kilograms. The crystal must conform to precise mechanical, electrical, chemical, and crystallographic standards. The crystal ingot is sliced into wafers which are polished and covered with an epitaxial layer having the same crystal structure as the wafer but different electrical properties. Understanding and controlling the growth processes involved in producing the single-crystal ingot and the epitaxial layer is crucial to manufacturing the high-quality starting material for today's very large scale integrated circuits.