Abstract: A wafer support device and an associated reactor system are provided which permit a wafer to be supported during the growth of a uniform epitaxial layer. The wafer support device includes a base and at least one contact member for supporting the wafer in a spaced relationship to the base. The base directs a portion of the gas through the space between the base and the back side of the wafer to facilitate the smooth flow of the gas. The wafer support device may also include a thermal mass proximate the edge of the wafer. The base may be formed of a material having greater thermal transparency than the material that forms the thermal mass such that the thermal mass will absorb and retain heat. Once heated, the thermal mass will therefore limit the heat that escapes from the edge of the wafer.

Abstract: A dopant (76), such as antimony, is cast around a seed crystal (10) to form a seed-dopant assembly (14) that facilitates doping of a molten semiconductor (36), such as silicon, in a crystal-growing furnace (34). To grow a doped ingot, the seed-dopant assembly is held in a relatively cool part of the furnace while the semiconductor is melted. When the semiconductor melt is ready for doping, the seed-dopant assembly is lowered to a position just above the melt. Heat transferred to the seed dopant assembly from the melt causes the dopant to drop off the seed into the molten semiconductor without splashing and without immersing the seed.