Physical Properties of N2O and NO-nitrided gate oxides grown on 4H-SiC

N2O and NO nitridation by either annealing or direct growth of gate oxides on 4H SiC is analyzed in this letter. The analysis is based on x-ray photoelectron spectroscopy binding energies and secondary ion mass spectroscopy depth profiles of nitrogen at the SiO2–SiC interface. A clean SiO2–SiC interface is found in both NO and N2O annealed/grown samples, as opposed to the interface annealed in Ar which exhibits complex suboxides and oxide–carbon compounds. The results demonstrate that nitridation in the industry-preferred N2O ambient could be as effective as nitridation in NO, provided appropriate process optimization is performed.