SiO2/Gd2O3/GaN metal oxide semiconductor field effect transistors

GaN-based metal oxide semiconductor field effect transistors (MOSFETs) were demonstrated using a stacked gate oxide consisting of single-crystal Gd2O3 and amorphous SiO2. Gd2O3 provides a good oxide/semiconductor interface and SiO2 reduces the gate leakage current and enhances oxide breakdown voltage. Charge modulation of the n-channel depletion mode MOSFET was achieved for gate voltage from +2 to -4 V. The source-drain breakdown voltage exceeded 80 V. An intrinsic transconductance of 61 mS/mm was obtained at a gate-source and drain-source bias of -0.5 and 20 V, respectively. This is the first demonstration of epitaxial Gd2O3 growth on GaN and the first use of Gd2O3 as an insulating layer for nitride electronic device applications. (C) 2001 The Electrochemical Society.