Patent ID: 7553366

Claim:
A crystallization method, comprising the steps of: preparing a substrate having an amorphous silicon layer deposited thereon; fixing the substrate to a stage; placing a laser beam pattern mask over the substrate, the laser beam pattern mask comprising at least one or more transmitting parts, each laser beam pattern including: a rectangular central portion; and a pair of edge portions provided to both sides of the central portion, each having a substantially triangular shape defined by a virtual boundary line between the central portion and the corresponding edge portion, an upper outside extending from an upper end of the boundary line at an acute angle, and a lower outside extending from a lower end of the boundary line at the acute angle to meet the upper outside at a rounded corner; and performing a laser beam irradiation for crystallizing the amorphous silicon using the laser beam pattern mask by overlapping the central portion of a next irradiation with an irradiated portion corresponding to the edge portion exposed in a previous irradiation.