Method of crystallizing a semiconductor thin film, and method of manufacturing a thin-film semiconductor device

Abstract

In crystallizing a semiconductor thin film of large area by overlapping regions of irradiation with a laser beam, uniform crystallinity of the film is achieved. A semiconductor thin film is crystallized by performing shaping laser light emitted to define a laser beam which has a predetermined intensity distribution in a predetermined irradiation region, and repeatedly irradiating the semiconductor thin film with the laser beam while scanning the film so that irradiation regions may be overlapped. The laser beam is shaped so that the sectional intensity distribution of the laser beam in the irradiation region as taken in the direction of the scanning may be convex, and that the peak of the intensity distribution lies at a position which is between the front end and rear end of the irradiation region in relation to the scanning direction and which is nearer to the front end with respect to the middle of the irradiation region. The laser beam is so shaped that an intensity at the front end of the irradiation region becomes lower in a range within 30% as compared with the intensity of the peak, and the intensity at the rear end of the irradiation region becomes lower in a range exceeding 5% as compared with the intensity of the peak.

Dependencies are inferred from the claim text.