Thermally converted surface layers in semi-insulating GaAs

Charge carrier transport in thermally converted surface layers in semi-insulating GaAs depends on the generation, diffusion, and occupancy of Ga and As vacancies. The amphoteric nature of C in GaAs can significantly alter the density and the distribution of donors and acceptors in the vicinity of the specimen surface and the surface layer may become either p type or n type depending on the thermal treatment conditions.