Passivation of an n-type GaAs surface with an As2S3 film

Abstract

This letter describes the passivation of an n-type GaAs surface using an arsenic trisulfide (As2S3) film. Metal–insulator—semiconductor diodes were fabricated with an evaporated As2S3 film as an insulator. In the inversion region, the capacitance–voltage curve shows deep depletion, that coincides with the depletion theory. In the accumulation region, surface Fermi level movement is blocked 0.25 eV below the conduction-band minimum due to a high density of interface states. The minimum interface state density is found to be about 1–2×1011 eV−1 cm−2.