Normally-Off C–H Diamond MOSFETs With Partial C–O Channel Achieving 2-kV Breakdown Voltage

Diamond has unique physical properties, which show great promise for applications in the next generation power devices. Hydrogen-terminated (C-H) diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) often have normally-on operation in devices, because the C-H channel features a p-type inversion layer; however, normally-off devices are preferable in power MOSFETs from the viewpoint of fail safety. We fabricated hydrogen-terminated (C-H) diamond MOSFETs using a partially oxidized (partial C-O) channel. The fabricated MOSFETs showed a high breakdown voltage of over 2 kV at room temperature and normally-off characteristics with a gate threshold voltage Vthof -2.5--4 V.