Optical and structural characterization of rapid thermal annealed non-stoichiometric silicon nitride film

A detailed optical and structural characterization is carried out of a silicon nitride film deposited by a Hg-sensitized photo-CVD technique and subsequently subjected to rapid thermal annealing (RTA). An attempt has been made to correlate ellipsometry data with x-ray reflectivity (XRR) and x-ray diffraction data. Both the optical constants and density of the film were found to increase after thermal treatment. RTA treatment resulted in substantial change in the refractive index with more compaction of the film. This is explained in terms of hydrogen terminated defects/voids created due to predominant out-diffusion of hydrogen with RTA treatment.