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 the thermal crystallization process in sputter deposited amorphous silicon films has been examined by extended energy-loss fine structure spectroscopy and transmission electron microscopy The coordination number and the mean square disorder of the first neighbor shell in the amorphous state were increased following X-ray irradiation. The crystallization by post-annealing was delayed, the crystallized particles were dispersed homogeneously throughout the film, and the size of the individual particles was larger than in samples 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.