Phase evolution and photoluminescence in as-deposited amorphous silicon nitride films

A systematic study of hydrogenated amorphous silicon nitride films deposited by varying gas flow rate ratio (R = SiH4/NH3) using Photo-Chemical Vapour Deposition reveal that as R is increased, dominant phase changes from silicon oxynitride to silicon nitride with embedded silicon nanoclusters. The change in photoluminescence spectral features in these films is attributed to quantum confinement effect. The results suggest that hydrogen plays a crucial role in overall phase evolution and in-situ formation of Si nanoclusters embedded in silicon nitride matrix.