Consideration of a Local Aluminum-Induced Crystallization Process Guided along the µ-Holes Fabricated with fs Laser Pulses

A polycrystalline silicon (poly-Si) film is produced by the aluminum-induced crystallization (AIC) process guided along the m-sized laser hole and characterized for application to a seeding layer of poly-Si solar cells. We investigated the crystallization of amorphous silicon (a-Si) films using the AIC process with a structure of glass/Al/SiO 2 /a-Si in which the silicon oxide (SiO 2 ) layer has holes with 1 ~ 2 m in diameter so that the AIC process occurred only through the hole. The purpose of our experiment is to see the poly-Si grain growth, if possible, from a single poly-Si seed in the AIC process. For the experiment, the microhole array of about 1 ~ 2 m in diameter is prepared in the SiO 2 layer of the structure using femtosecond laser pulses and the AIC process is carried out with the conventional heat treatment procedure. As results, it is observed that the crystallization of a-Si occurred only in the area under the microhole and the grain of poly-Si grew to the size of over 3 m. Furthermore, it was shown that the grain grew with one dominant crystal orientation.