High-Performance P-Channel Diamond Metal–Oxide–Semiconductor Field-Effect Transistors on H-Terminated (111) Surface

Abstract

Through the enhancement of hole accumulated density near hydrogen-terminated (111) diamond surfaces, low sheet resistance (∼5 kΩ/sq) has been obtained compared with widely used (001) diamond surfaces (∼10 kΩ/sq). Using the hole accumulation layer channel, a high drain current density of -850 mA/mm was obtained in p-channel metal–oxide–semiconductor field-effect transistors (MOSFETs). This drain current density is the highest value for diamond FETs. The high drain current on the (111) surface is attributed to two factors: The low source and drain resistances owing to the high hole carrier density and the high channel mobility at a high gate–source voltage on the (111) surface.