Patent ID: 6281470
Filing Date: 2001-08-28
Classification: H01L

Abstract:
A laser annealing apparatus executing laser annealing of a thin film semiconductor device comprising:a laser light source which emits a laser beam;an optical system which transforms a cross-section shape of the laser beam from the laser light source into a rectangular shape and adjusts a beam width of the laser beam;a laser beam scan section which scans the laser beam over a polycrystalline silicon film while allowing the pitch in the scan direction to be adjustable;a beam output control section which controls the beam output of the laser beam from the laser light source;a scan direction control section which rotates the laser beam scan direction every approximately 90 degrees or by a specified angle along a scan plane;an unevenness measurement section sensing the surface of the annealed polycrystalline silicon film and generating an indication of surface unevenness of the film, anda control section which controls operations of the optical system, the laser beam scan section, the beam output control section and the scan direction control section so that the active layers of all the semiconductor elements belonging to each of the unit circuits are formed in only one of the plurality of regions classified by the size of the surface unevenness of the polycrystalline silicon film, wherein said control section applies the indication of surface unevenness to determine the regions classified by the size of surface unevenness.