Raman study of silicon nanocrystals formed in SINx films by excimer laser or thermal annealing

Silicon nitride films of different stoichiometric composition were studied using Raman spectroscopy. A Raman signal due to Si-Si, Si-N bond vibrations in silicon nanoclusters was detected in as-deposited films. The appearance of Raman peaks in the range 493-514 cm(-1) after thermal and pulse laser t reatments was interpreted as formation of silicon nanocrystals with sizes f rom 1.3 up to 5 nm depending on treatment parameters. Thermal treatment at 1200 degrees C allowed Si atom diffusion and its gathering in Si nanocrysta ls, meanwhile 5 ns pulse laser irradiation leads to crystallization of pree xisting silicon nanoclusters inside the as-deposited SiNx films. (C) 1998 A merican Institute of Physics. [S0003-6951(98)03334-8].