Depletion-mode vertical Ga2O3trench MOSFETs fabricated using Ga2O3homoepitaxial films grown by halide vapor phase epitaxy

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