Comparison of nitrogen incorporation in SiO/sub 2//SiC and SiO/sub 2/Si structures

Abstract

The nitrogen content of SiO2/SiC (4H) structures annealed in NO and N2O has been measured using nuclear reaction analysis. Samples were annealed in 15N18O or 15N2O at 1000 °C at a static pressure of 10 mbar for either 1 or 4 h. Annealing in N2O incorporates ~1013 cm22 of N and annealing in NO incorporates ~1014 cm-2, both of which are an order of magnitude lower than in SiO2/Si. In the NO anneal, N is predominantly incorporated near the SiO2/SiC interface with an atomic concentration of ~0.5%. As in the nitridation of SiO2/Si, two features are observed in SiO2/SiC after the NO anneal: a surface exchange of O in the oxide with the gas phase and NO diffusion and reaction at the interface. The surface exchange reaction in SiO2/SiC is similar to SiO2/Si, but there is a large difference in the incorporation of N at the interface.