Patent ID: 7008863

Claim:
A method for forming a polycrystalline silicon film by crystallizing an amorphous silicon film, which is formed on a glass substrate by interposing a buffer layer therebetween, by irradiating a laser beam onto the amorphous silicon film using a predetermined mask, the method comprising the steps of: i) dividing an area of the predetermined mask into first, second, and third shot regions, a first shot region having a plurality of non-overlapping first transmission sections arranged in a first column along a y-direction, a second shot region having a plurality of non-overlapping second transmission sections arranged in a second column along the y-direction, a third shot region having a plurality of non-overlapping third transmission sections arranged in a third column along the y-direction. wherein the second column of second transmission sections is formed in between the first and third columns along the x-direction in a non-overlapping manner, wherein each second transmission section is positioned to correspond to a non-transmission section between two first transmission sections in the first column along the x-direction such that the width in the y-direction of each second transmission section in the second column is wider than the width in the y-direction of the corresponding non-transmission section in the first column, and wherein each third transmission section in the third column is positioned to correspond along the x-direction to one of first and second transmission sections in the first and second columns such that the width in the y-direction of the third transmission section is less than the width in the y-direction of the corresponding one of first and second transmission sections in the first and second columns; and ii) performing primary to n th laser irradiation processes with respect to the glass substrate by using the mask having a mask pattern while moving the glass substrate in a predetermined direction by a predetermined distance, thereby crystallizing the amorphous silicon film.