Corrosion-induced degradation of GaAs PHEMTs under operation in high humidity conditions

We have comprehensively investigated the degradation mechanism of AlGaAs/InGaAs pseudomorphic high-electron-mobility transistors (PHEMTs) under operation in high humidity conditions. PHEMTs degradation under high humidity with bias consists of a decrease in maximum drain current (Imax) caused by a corrosion reaction at the semiconductor surface at the drain side. The decrease in Imax is markedly accelerated by the external gate–drain bias (Vdg). This originates from a reduction in the actual activation energy (Ea0) by Vdg. The degradation depends on the surface treatment prior to deposition of the SiNx passivation film. The reduction of As-oxide at the SiNx/semiconductor interface suppresses the corrosion reaction.