Gate-first process compatible, high-quality in situ SiNx for surface passivation and gate dielectrics in AlGaN/GaN MISHEMTs

In the research of passivation/gate dielectrics for AlGaN/GaN based high electron mobility transistors (HEMTs), in situ SiNx has specific advantages over ex situ SiNx in terms of lower defects level and higher dielectric quality. In this paper, an in situ grown SiNx layer as thick as 47 nm was deposited on AlGaN/GaN heterostructure by metalorganic chemical vapor deposition, with capabilities of functioning simutanously as passivation and gate dielectrics verified. Systematical investigations have been performed on the in situ SiNx in aspects of bulk dielectric quality, interface property and dielectric reliability. Correspondingly, high leakage suppression ability with leakage current