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

Abstract

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 ( I max) caused by a corrosion reaction at the semiconductor surface at the drain side. The decrease in I max is markedly accelerated by the external gate–drain bias ( V dg ). This originates from a reduction in the actual activation energy ( E a 0) by V dg . The degradation depends on the surface treatment prior to deposition of the SiN x passivation film. The reduction of As-oxide at the SiN x /semiconductor interface suppresses the corrosion reaction.