Effect of the oxidation process on the electrical characteristics of 4H–SiC p-channel metal-oxide-semiconductor field-effect transistors

We fabricated inversion-type 4H–SiC p-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). The electrical properties of the p-channel MOSFETs depended on the gate oxidation process. We found that wet oxidation process was effective for improving the channel mobility of the p-channel MOSFET, and obtained the field-effect channel mobility μFE of 15.6cm2∕Vs by using that process. Measurements of the p-type MOS capacitors implied that the SiO2∕SiC interface states around the valence band affected the channel mobility and threshold voltage of the p-channel MOSFETs. We also investigated temperature dependences.