Laser irradiation apparatus, thin film transistor, and method of manufacturing thin film transistor

A laser irradiation apparatus comprising:

• a light source that generates a laser beam;
• a projection lens that radiates the laser beam onto a predetermined region of an amorphous silicon thin film deposited between a source electrode and a drain electrode included in each of a plurality of thin film transistors on a glass substrate to form a polysilicon thin film;
• and
• a projection mask pattern provided on the projection lens and having a plurality of openings and that separates the laser beam into a plurality of laser beams so that at least one of the laser beams is radiated onto each of the plurality of thin film transistors,
• wherein the projection lens radiates the laser beams onto the plurality of thin film transistors on the glass substrate, which moves in a predetermined direction, through the projection mask pattern,
• the projection mask pattern is provided such that the plurality of openings are not continuous in one column orthogonal to the moving direction, and
• in the plurality of thin film transistors onto which the laser is beams are radiated, the laser beams different from each other are radiated through the projection mask pattern onto corresponding amorphous silicon thin films adjacent to each other of the thin film transistors adjacent to each other.