SiO[sub 2]/Gd[sub 2]O[sub 3]/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 and amorphous provides a good oxide/semiconductor interface and 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 growth on GaN and the first use of as an insulating layer for nitride electronic device applications.