Self-Orientation of Silicon Nanocrystals Created under Pulse Laser Impact in Stressed a-Si:H Films on Glass Substrates

摘要

Using of Raman scattering spectroscopy and electron microscopy techniques it was observed that nanosecond pulse ultraviolet laser radiation impacts lead to formation into a-Si:H films nanocrystals with preferred (110) orientation and sizes from 2 nm and bigger. Polarization anisotropy of the Raman scattering was observed in the system of mutual-oriented silicon nanocrystals. The anisotropy is established to be the result of planar correlated orientation of nanocrystals, what makes possible to determine the part of the oriented nanocrystals. It is proposed, that preferred orientation is due to both elastic stress in the films and local deformations appearing around the nanocrystals. Features of "explosive" crystallization during excimer laser impact proved significance of stresses in crystallization of a-Si:H films on glass substrates were observed.