Characterization of deep traps in the near-interface oxide of widegap metal–oxide–semiconductor interfaces revealed by light irradiation and temperature change

Abstract

To evaluate oxide trap state density in the near interface region of silicon carbide metal-oxide-semiconductor (SiC MOS) stacks, photo-assisted capacitance-voltage measurements at various temperatures were performed. The difference between the deep trap profiles at SiC MOS interfaces treated with two kinds of post-oxidation-annealing was revealed, which cannot be detected by conventional evaluation methods of interface state density. With this method, the differences in energy profile of trap levels together with their spatial distribution in near interface region of oxide were investigated.