SIMS analysis of nitrided oxides grown on 4H-SiC

This paper shows for the first time, physical evidence of nitrogen incorporation at the oxide-SiC interface as a result of post-oxidation annealing in nitric oxide (NO). Using secondary ion mass spectroscopy (SIMS) analysis, the location and shape of the nitrogen profile is seen to be almost identical to that found in oxide-silicon interfaces. Close examination of oxygen and carbon SIMS profiles and atomic force microscope scans also indicate a sharper interface when annealing is done using NO compared to inert gases such as N2 or argon, possibly due to the removal of carbon clusters which form at the interface during oxidation. As in the case of silicon, NO annealing shows great promise as a processing step in the production of device quality gate oxides on SiC.