SiO[sub 2]/Gd[sub 2]O[sub 3]/GaN Metal Oxide Semiconductor Field Effect Transistors

Abstract
GaN-based metal oxide semiconductor field effect transistors (MOSFETs) were demonstrated using a stacked gate oxide consisting of single-crystal Gd2O3Gd2O3 and amorphous SiO2.SiO2. Gd2O3Gd2O3 provides a good oxide/semiconductor interface and SiO2SiO2 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 Gd2O3Gd2O3 growth on GaN and the first use of Gd2O3Gd2O3 as an insulating layer for nitride electronic device applications. © 2001 The Electrochemical Society. All rights reserved.