LASER BEAM IRRADIATING DEVICE AND METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical system which can reduce the weak interference that is observed when laser annealing is performed on a semiconductor film. SOLUTION: The weak interference seen when laser annealing is performed on semiconductor films can be reduced by irradiating the semiconductor film with a laser beam by using the optical system containing a mirror 1006. The mirror 1006 splits the laser beam into split laser beams, makes the optical path differences from a laser oscillator to the surfaces irradiated with the split laser beams equal to or longer than the coherent length of the original laser beam, and makes the energy of the split laser beams uniform on the irradiated surfaces. Therefore, when the semiconductor film is irradiated with the laser beam through the mirror 1006, the weak interference can be reduced. In addition, the optical system which has been difficult to be adjusted can be simplified.