Nitrogen transport during rapid thermal growth of silicon oxynitride films in N/sub 2/ O

Abstract

We investigated the transport of nitrogenous species during rapid thermal growth of silicon oxynitride films on Si in N2O, using N isotopic tracing and high resolution depth profiling techniques. The results indicate that the diffusion of nitrogenous species ~most probably NO! through the growing oxynitride film to react with Si at the oxynitride/Si interface, induces the incorporation of N near this interface. This mechanism acts in parallel with a site-to-site jump mechanism ~interstitialcy or vacancy! of diffusion and chemical reaction of nitrogenous species in the volume of the growing oxynitride film. The characteristic N accumulation only near the interface obtained by rapid thermal processing growth in N2O is due to the removal of N from the near surface region of the films, here attributed to atomic exchanges O-N taking place during growth. Furthermore, N-N exchange was also observed.