Depletion-mode vertical Ga2O3 trench MOSFETs fabricated using Ga2O3 homoepitaxial films grown by halide vapor phase epitaxy

We developed depletion-mode vertical Ga2O3 trench metal-oxide-semiconductor field-effect transistors by using n(+) contact and n(-) drift layers. These epilayers were grown on an n(+) (001) Ga2O3 single-crystal substrate by halide vapor phase epitaxy. Cu and HfO2 were used for the gate metal and dielectric film, respectively. The mesa width and gate length were approximately 2 and 1 mu m, respectively. The devices showed good DC characteristics, with a specific on-resistance of 3.7m Omega cm(2) and clear current modulation. An on-off ratio of approximately 10(3) was obtained. (C) 2017 The Japan Society of Applied Physics