Process and equipment considerations in the implantation of GaAs

Ion implantation of GaAs presents process requirements differing from standard silicon processing. Different implant species having differing source requirements are commonly used. GaAs devices may be susceptible to different contaminants, including some which are common construction materials in implanters intended for silicon implant applications. Because of its physical characteristics, GaAs poses different handling challenges. In some situations, implantation of GaAs at elevated temperatures is preferred. We examine some of these differences between silicon and GaAs processing and describe standard features and optional adaptations of a medium current ion implanter that facilitates processing of GaAs. These include source adaptations, wafer clamping and sensing adaptations, and a capability to implant at elevated substrate temperatures