Improvement in Electrical Characteristics of Low-Pressure Chemical-Vapor-Deposited SiN_xDielectric Layer on GaN Substrate by Ammonium Sulfide Treatment

Abstract

The electrical characteristics of low-pressure chemical-vapor-deposited SiN x on GaN and ammonium sulfide-treated GaN substrate were investigated. Upon ammonium sulfide treatment, the leakage current densities of SiN x /GaN were reduced from 1:82 Â 10 À9 to 2 Â 10 À10 A/cm 2 and from 4:44 Â 10 À9 to 1:6 Â 10 À9 A/cm 2 under electric fields of AE1 MV/cm, respectively. The negative effective oxide charges were improved from À1:39 Â 10 13 to À4:1 Â 10 12 C/cm 2 . The ammonium sulfide treatment improves the interface and film qualities of SiN x /GaN.