Influnence of deposition position on the microstructure of nanocrrystalline Si film fabricated by pulsed laser deposition

Nanocrystalline silicon film are prepared by pulsed laser ablation under 4.0×10-4Pa and post-annealing in nitrogen.The surface profit measuring system,scanning electron microscopy and Raman spectrum are used to investigate the microstructure at different positon of the film.The results indicate that the film thickness and distribution of the nc-Si grain size are non-uniform.With increasing the distance between the measured position and the film center,the film thickness gradually decreases and the grain size of nc-Si increases,which can be explain qualitatively by the plume dynamics of pulsed laser ablation.