345-MW/cm2 2608-V NO2 p-type Doped Diamond MOSFETs with an Al2O3 Passivation Overlayer on Heteroepitaxial Diamond

Diamond metal oxide semiconductor field effect transistors (MOSFETs) on high-quality heteroepitaxial diamond (Kenzan diamond®) with NO2 p-type doping and an Al2O3 passivation overlayer exhibited a high off-state breakdown voltage of −2608 V. The 100-nm-thick Al2O3 passivation overlayer on the hole channel increased the high-voltage-handling capability of the MOSFETs by substantially suppressing the off-state drain leakage currents. The MOSFET showed a specific on-resistance of 19.74 $\text{m}\Omega \cdot $ cm2 and a maximum drain current density of −288 mA/mm, with an extremely low gate leakage current $ mA/mm. The Baliga’s Figure-Of-Merits was experimentally determined to be 344.6 MW/cm2, and the maximum DC power density was observed to be 21.0 W/mm.