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 photoe lectron spectroscopy binding energies and secondary ion mass spectroscopy d epth profiles of nitrogen at the SiO2-SiC interface. A clean SiO2-SiC inter face 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-preferr ed N2O ambient could be as effective as nitridation in NO, provided appropr iate process optimization is performed. (C) 2001 American Institute of Phys ics.