Microscopic difference between dry and wet oxidations of C-face 4H-SiC MOSFFETs studied by electrically detected magnetic resonance

摘要

We studied interface defects of C-face 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) by means of electrically-detected-magnetic-resonance (EDMR) spectroscopy. EDMR measurements were carried out on opposite types of C-face MOSFETs, which were fabricated by dry oxidation and wet oxidation, and revealed EDMR signals of interface defects from both the MOSFETs. Judging from their g factors, the interface signals of the two MOSFETs are the same type, and we call them "C-face defects." The densities of C-face defects were found to be larger in the dry-oxide MOSFETs than in the wet-oxide MOSFETs. It is also revealed that C-face defects in wet-oxide MOSFETs are coupled with hydrogen atoms.