Laser annealing method, laser annealing apparatus, and manufacturing process for thin film transistor

A laser annealing apparatus for executing laser annealing on an amorphous silicon thin film in a region corresponding to a gate electrode on a substrate to form a semiconductor layer of a thin film transistor,

• the apparatus comprising:
• an optical system configured to multiply irradiate laser light while changing an irradiation area of the laser light such that the amorphous silicon thin film in regions corresponding to a source electrode and a drain electrode, respectively are irradiated with a smaller irradiation amount than the amorphous silicon thin film in a channel region between the source electrode and the drain electrode;
• and
• control means configured to control the optical system to change the irradiation area of the laser light.