Thermal oxidation of SiC in N2O

Thermal oxidation kinetics of 3C and 6H-SiC in N2O at 1050 to 1150 C have been studied. The oxidation rate follows an unusual parabolic-linear relationship that has also been found for oxidation of silicon in N2O. The activation energy of the parabolic rate constant (B) is 3.1 +/- 0.22 eV/molecule for 3C-SiC, and 4.80 -+ 1.02 eV/molecule for 6H-SiC. The limiting mechanism for oxidation is attributed to the diffusion of CO through the oxynitride layer. 3C-SiC metal oxide semiconductor capacitors fabricated in N2O exhibit fixed oxide charge densities on the order of 10 exp 12/sq cm and are slightly lower than those oxidized in steam. (Author)