Performance improvement in 4H-SiC(0001) p-channel metal-oxide-semiconductor field-effect transistors with a gate oxide grown at ultrahigh temperature

Abstract

We fabricated 4H-SiC(0001) p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) with gate oxide formed at 1600 °C under an oxygen partial pressure of 0.3 kPa. The fabricated pMOSFETs showed superior performance, suggesting suppression of carbon-related defects at the SiO2/SiC interface. A further performance improvement was achieved by subsequently employing forming gas annealing at 1200 °C. In particular, a peak field-effect mobility of up to 13 cm2V−1 s−1, 11% of the intrinsic hole mobility, was demonstrated. Moreover, the transistors had a stable threshold voltage up to 200 °C and high immunity against bias-temperature stress, suggesting improved reliability.