Direct Measurement of Active Near-Interface Traps in the Strong-Accumulation Region of 4H-SiC MOS Capacitors

This brief presents direct electrical measurement of active defects in the strong-accumulation region of N-type 4H-SiC MOS capacitors, which corresponds to the strong-inversion region of N-channel MOSFETs. The results demonstrate the existence of an active defect in the gate oxide, located very close to the SiC surface, with localized energy levels between 0.13 eV and 0.23 eV above the bottom of the conduction band. The observed spatial and energy localizations indicates that this is a well-defined defect.