Crystallization of amorphous silicon beyond the crystallized polycrystalline silicon region induced by metal nickel

Crystallization of amorphous silicon (a-Si) which starts from the middle of the a-Si region separating two adjacent metal-induced crystallization (MIC) polycrystalline silicon (poly-Si) regions is observed. The crystallization is found to be related to the distance between the neighboring nickel-introducing MIC windows. Trace nickel that diffuses from the MIC window into the a-Si matrix during the MIC heat-treatment is experimentally discovered, which is responsible for the crystallization of the a-Si beyond the MIC front. A minimum diffusion coefficient of 1.84×10^-9 cm²/s at 550℃ is estimated for the trace nickel diffusion in a-Si.