Passivation of (NH4)2S-treated GaAs surface with an As2S3 film

Abstract
This letter describes the suppression of (NH4)2S‐treated GaAs surface degradation by coating the treated surface with an evaporated As2S3 film. The photoluminescence intensity of the treated GaAs surface shows no decrease even after 100 days. The properties of the As2S3/GaAs interface were also evaluated by metal‐insulator‐semiconductor techniques. A small hysteresis capacitance‐voltage curve with reduced frequency dispersion was obtained, which indicates low interface state density. The passivation of the (NH4)2S‐treated surface by coating with an As2S3 film is very promising for GaAs surface electronic property improvements.