High-mobility SiC MOSFET with low density of interface traps using high pressure microwave plasma oxidation

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@E_c - 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.