ABSTRACT
Effects of wet atmosphere during oxidation and anneal on thermally oxidized SiC MOS interface properties were systematically investigated. Deep interface states and fixed oxide charges were mainly discussed. The wet atmosphere was effective to reduce a negative flatband shift caused by deep donor-type interface states in p-type SiC MOS capacitors. Negative fixed charges, however, appeared near the interface during wet re-oxidation anneal. The relation between interface properties and characteristics of nchannel planar 6H-SiC MOSFETs was also investigated. The threshold voltage of MOSFETs processed by wet re-oxidation anneal was higher than that without re-oxidation anneal. A clear relation between the threshold voltage and the channel mobility was observed in MOSFETs fabricated on the same substrate.
