The effects of the oxidation atmosphere and crystal faces on the interface-trap density was examined by using constant-capacitance deep-level transient spectroscopy to clarify the origin of them. By comparing the DLTS spectra of the low-mobility interfaces oxidized in a N2O atmosphere with those of the high-mobility interfaces on C-face oxidized in a wet atmosphere, it was found that a high density of traps are commonly observed around the energy of 0.16 eV from the edge of the conduction band (C1 traps) in low-mobility interfaces irrespective of crystal faces. It was also found that the generation and elimination of traps specific to crystal faces: (1) the C1 traps can be eliminated by wet oxidation only on the C-face, and (2) the O2 traps (0.37 eV) can be observed in the SiC/SiO2 interface only on the Si-face. The generation of O2 traps on the Si-face and the elimination of C1 traps on the C-face by wet oxidation may be caused by the oxidation reaction specific to the crystal faces.
@article{arxiv.1409.7170,
title = {Characterization of Interface Traps in SiO$_2$/SiC Structures Close to the Conduction Band by Deep-Level Transient Spectroscopy},
author = {Tetsuo Hatakeyama and Mitsuru Sometani and Yoshiyuki Yonezawa and Kenji Fukuda and Hajime Okumura and Tsunenobu Kimoto},
journal= {arXiv preprint arXiv:1409.7170},
year = {2015}
}