Investigation on optical and microstructural properties of photoluminescent LPCVD SiOxNy thin films

Abstract Amorphous silicon oxynitride (a-SiOxNy) films of various compositions were deposited by low-pressure chemical vapour deposition (LPCVD) at 860°C and 400 mTorr, using a mixture of SiCl2H2–NH3–N2O. The dependence of the film properties on the deposition temperature and the gas flow ratio was studied by spectroellipsometry (SE) and infrared spectroscopy (IR). To calculate the optical and microstructural parameters of the films from SE data, three different approaches (Bruggeman-EMA, Cauchy and Sellmeier) were used. The comparison of the results shows a good agreement between all three models. Photoluminescence (PL) phenomena in as-deposited LPCVD silicon oxynitride are presented and compared to results reported in literature.