Patent ID: 7569439

Claim:
A process for producing a thin film semiconductor device by crystallizing a semiconductor thin film over a dielectric substrate having a warping point of 600° C. or lower, using laser annealing, comprising the steps of: forming a semiconductor thin film over the substrate; disposing a plurality of insulation film bands at substantially given spacing on the semiconductor thin film, the insulation film bands having such a film thickness as to prevent reflection of a laser beam; setting reflectively against the laser beam of the semiconductor thin film region covered with the insulation film bands as R 2 ; setting reflectively against the laser beam of the semiconductor thin film region uncovered with the insulation film bands as Rl, amount of reflectivity of Rl being larger than that of R 2 ; setting width of the semiconductor thin film region covered with the insulation film bands as smaller than that of the semiconductor thin film region uncovered with the insulation film bands; and irradiating the laser beam while shifting the substrate in substantially parallel with a longitudinal direction of the insulation film bands relative to the laser beam.