The influence of X-ray irradiation on structural relaxation and crystallization of amorphous silicon films

The effect of intense X-ray irradiation on the short range structure and th e thermal crystallization process in sputter deposited amorphous silicon fi lms has been examined by extended energy-loss fine structure spectroscopy a nd transmission electron microscopy. The coordination number and the mean s quare disorder of the first neighbor shell in the amorphous state were incr eased following X-ray irradiation. The crystallization by post-annealing wa s delayed, the crystallized particles were dispersed homogeneously througho ut the film, and the size of the individual particles was larger than in sa mples without X-ray irradiation. The above facts suggest that the number of unsaturated bonds is reduced by the X-ray irradiation, which can suppress the atomic diffusion and rearrangement, necessary for the crystallization.