Threshold voltage control using SiNx in normally off AlGaN/GaN HFET with p‐GaN gate

Abstract

AbstractThe threshold voltage (Vth) of normally off‐mode AlGaN/GaN junction heterostructure field‐effect transistors with a p‐type GaN gate can be successfully controlled by inserting a SiNx insulator between the p‐GaN and a Ni/Au electrode. The Vth can be controlled from +1 V to above +8 V. Moreover, the gate leakage current of transistors decreases and their gate voltage at which gate current steeply increases becomes higher. The mechanism of the threshold voltage change is analyzed by the equivalent circuit model. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)