Patent ID: 7557050

Claim:
A method of manufacturing a polysilicon thin film comprising: irradiating a laser beam generated from a laser unit onto a first portion of an amorphous silicon thin film to liquefy the first portion of the amorphous silicon thin film, the laser beam having a beam shape including a first width substantially in parallel with the first direction and a second width substantially in parallel with a second direction substantially perpendicular to the first direction, the second width being greater than the first width, the beam shape being substantially the same shape as a shape of the laser beam irradiated onto the first portion, the first portion of the amorphous silicon thin film being on a first end portion of a substrate; crystallizing the liquefied silicon of the first portion to form silicon grains; transporting the substrate for shifting the laser beam by an interval in a first direction from the first end portion toward a second end portion of the substrate opposite the first end portion; irradiating the laser beam onto a second portion of the amorphous silicon thin film to liquefy the second portion of the amorphous silicon thin film, the second portion partially overlapping the first portion; and crystallizing the liquefied silicon of the second portion to extend the silicon grains to form a first polysilicon thin film, wherein the interval of the laser beam is no more than about a half of the first width of the beam shape of the laser beam.