Ga₂O₃ metal-oxide-semiconductor field effect transistors on sapphire substrate by MOCVD

Si-doped gallium oxide (Ga₂O₃) thin films were grown on a c-plane sapphire substrate by metalorganic chemical vapor deposition (MOCVD) and fabricated into metal oxide semiconductor field effect transistors (MOSFETs). The Ga₂O₃ MOSFETs exhibited effective gate modulation of the drain current with a complete channel pinch-off for V_G <-25 V, and the three-terminal off-state breakdown voltage was 390 V. The device shows a very low gate leakage current (∼50 pA mm^-1), which led to a high on/off ratio of ∼10⁸. These transistor characteristics were stable from room temperature to 250°C.