Enhancement-Mode Ga2O3 Vertical Transistors With Breakdown Voltage > 1 kV

High-voltage vertical Ga2O3 MISFETs are developed employing halide vapor phase epitaxial (HVPE) layers on bulk Ga2O3 (001) substrates. The low charge concentration of similar to 10(16) cm(-3) in the n-drift region allows three terminal breakdown voltages to reach up to 1057 V without field plates. The devices operate in the enhancement mode (E-mode) with a threshold voltage of similar to 1.2-2.2V, a current on/off ratio of similar to 108, an on resistance of similar to 13-18m Omega.m(2), and an output current of > 300 A/cm(2). This is the first report of high-voltage vertical Ga2O3 transistors with E-mode operation, a significant milestone toward realizing Ga2O3 based power electronics.