Application of the charged pointhyphen;defect model to diffusion and interdiffusion in GaAs

摘要

Diffusion and interdiffusion in GaAs and GaAs/AlGaAs superlattices are shown to be consistent with the charged pointhyphen;defect model. The charged Ga vacanciesV3minus;Gaand interstitialsI2+Gaappear to control group II, III, and probably V element diffusion. After adjustment for carrier concentration and As pressure, these elements are found to have a nearly identical intrinsic diffusivity and activation energy over a wide range of temperature. A natural consequence of Ga diffusion via negative or positive point defects is that enhanced grouphyphen;III interdiffusion is expected with eithernhyphen; orphyphen;type doping. Anomalous enhancements in grouphyphen;II dopant diffusivity have been related to the supersaturation of Ga interstitials.