Patent ID: 8735233

Claim:
A manufacturing method for a thin film semiconductor device, comprising: preparing a substrate; forming a gate electrode above the substrate; forming a gate insulating film above the substrate; forming a source electrode and a drain electrode above the substrate; forming a silicon thin film above the substrate; and forming a crystalline silicon thin film by irradiating the silicon thin film with a laser beam while scanning the silicon thin film with the laser beam in a scanning direction relative to the silicon thin film so as to crystallize the silicon thin film; wherein the laser beam is a continuous wave laser beam, an intensity distribution of the laser beam in a first region about a center of the intensity distribution is symmetric on an anterior side and a posterior side of the center relative to the scanning direction with a maximum intensity at the center, the intensity distribution of the laser beam in a second region about the center is asymmetric on the anterior side and the posterior side of the center relative to the scanning direction, the first region being from the maximum intensity of the laser beam to an intensity half of the maximum intensity, the second region being at most equal to the half of the maximum intensity of the laser beam, and in the second region, a second integral intensity value of the intensity distribution of the laser beam on the posterior side of the center relative to the scanning direction is larger than a first integral intensity value of the intensity distribution of the laser beam on the anterior side of the center relative to the scanning direction.