Editors' Choice Communication—A (001) β-Ga₂O₃MOSFET with +2.9 V Threshold Voltage and HfO₂Gate Dielectric

Abstract

An MOS transistor fabricated on (001) β-Ga2O3 exfoliated from a commercial (−201) β-Ga2O3 substrate is reported. A maximum drain current of 11.1 mA/mm was measured, and a non-destructive breakdown was reached around 80 V in the off state. Threshold voltage of +2.9 V was extracted at 0.1 V drain bias, and peak transconductance of 0.18 mS/mm was measured at VDS = 1 V, corresponding to a field effect mobility of 0.17 cm2/Vs. Hall effect and electron spin resonance data suggested that electron conductivity was due primarily to O vacancy donors (VO+) with an estimated density of 2.3 × 1017 (±50%) cm−3.