High-mobility SiC MOSFET with low density of interface traps using high pressure microwave plasma oxidation**Project supported in part by the National Key Research and Development Program of China (Grant No. 2016YFB0100601), the National Natural Science Foundation of China (Grant Nos. 61674169 and 61974159), and the Support from a Grant-In-Aid from the Youth Innovation Promotion Association of the Chinese Academy of

Abstract

The microwave plasma oxidation under the relatively high pressure (6 kPa) region is introduced into the fabrication process of SiO2/4H-SiC stack. By controlling the oxidation pressure, species, and temperature, the record low density of interface traps (∼ 4 × 1010 cm−2⋅eV−1@Ec − 0.2 eV) is demonstrated on SiO2/SiC stack formed by microwave plasma oxidation. And high quality SiO2 with very flat interface (0.27-nm root-mean-square roughness) is obtained. High performance SiC metal–oxide–semiconductor field-effect transistors (MOSFETs) with peak field effect mobility of 44 cm−2 ⋅eV−1 is realized without additional treatment. These results show the potential of a high-pressure plasma oxidation step for improving the channel mobility in SiC MOSFETs.