Field-Plated Ga 2 O 3 MOSFETs With a Breakdown Voltage of Over 750 V

Depletion-mode field-plated Ga 2 O 3 metal-oxide-semiconductor field-effect transistors were demonstrated for the first time. Substantial enhancement in breakdown voltage was achieved with a gate-connected field plate. The device channels, formed by selective-area Si ion implantation doping of an undoped Ga 2 O 3 epilayer, were electrically isolated by the highly resistive epilayer without mesa etching. Effective surface passivation and high Ga 2 O 3 material quality contributed to the absence of drain current collapse. The transistors exhibited an off-state breakdown voltage of 755 V, a high drain current on/off ratio of over 10 9 , and stable high temperature operation against 300°C thermal stress.