Evidence of clusters size-dependent photoluminescence on silicon-rich silicon oxynitride films

This work reports on the growth of silicon clusters within silicon oxynitride (SiOxNy) matrices, at low temperatures, by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique. The films were characterized by Fourier transform infrared spectroscopy (FTIR), soft X-ray absorption spectroscopy (XANES) measurements at the Si K-edge and photoluminescence, before and after thermal annealing at various temperatures. The XANES spectra demonstrate the presence of silicon aggregates in as-deposited and annealed films. A correlation between the presence of silicon clusters in the as-deposited samples and the intensity of the photoluminescence emission is observed.