Characterization of 4H-SiC MOSFETs with NO-Annealed CVD Oxide

Deposited oxide is an attractive gate oxide due to absence of carbon at the MOS interface. We fabricated and characterized Si-face 4H-SiC n-MOS capacitors and n-channel MOSFETs with CVD oxide annealed in NO at 1250°C and compared to those with dry thermal oxide. Nitrogen and carbon distribution in the oxide was evaluated by SIMS. The CVD/NO sample has lower interface state density near the conduction band edge, higher nitrogen concentration at the interface and lower carbon concentration in the oxide than the Dry/NO sample. Channel mobility of 27.7cm 2 /Vs was obtained for the CVD/NO sample, which is higher than the Dry/NO sample (24.9cm 2 /Vs). These MOSFET performances are correlated with the results of n-MOS capacitors and SIMS measurements.