Optical and Physical Characterization of SRSO and SRSN Gradient Thin Films

Silicon rich silicon nitride （SRSN） and silicon rich silicon oxide （SRSO） thin films were deposited by gradually varying nitrogen or oxygen concentrations, in order to achieve a variable composition along the film thickness. Post-deposition, films were thermally annealed in a quartz tube furnace under several annealing conditions. The optical and structural properties of the annealed films were characterized through photoluminescence （PL） measurements and transmission electron microscopy （TEM） analysis. Annealing strongly influenced the PL spectra of the films, showing features originating either from defects or in other cases, from the formation of silicon nanostructures.