Phosphidization of GaAs by a remote phosphine plasma process and its application to surface passivation of GaAs metal–semiconductor field-effect transistors

Abstract

Surface passivation of GaAs due to phosphidization is investigated. GaAs surfaces are treated with a remote plasma of phosphine (PH3) diluted with Ar. X-ray photoelectron spectroscopy analysis reveals that the PH3 plasma treatment removes native oxide from GaAs surfaces and that generation of As oxide is suppressed on phosphidized surfaces. Photoluminescence intensity is enhanced for phosphidized GaAs. The PH3 plasma treatment is applied to surface passivation of GaAs metal–semiconductor field-effect transistors. A significant increase of the drain current and the transconductance is achieved. These results strongly suggest that the surface states have been passivated.