Depletion-mode Ga2O3 MOSFETs on β-Ga2O3 (010) substrates with Si-ion-implanted channel and contacts

Depletion-mode Ga
₂
O
₃
MOSFETs were fabricated on single-crystal β-Ga
₂
O
₃
(010) substrates. We applied Si-ion implantation to the ohmic contacts for low contact resistance as well as to the channel layer for reliable doping. An Al
₂
O
₃
gate dielectric film formed by atomic layer deposition passivated the device surface and significantly reduced gate leakage. The MOSFETs with a simple structure exhibited complete channel pinch-off with a breakdown voltage of 415 V and a drain current on/off ratio of ten orders of magnitude at room temperature. The devices also showed stable operation up to 250°C.