Patent ID: 7101436

Claim:
A crystallization apparatus which comprises an optical illumination system to emit a light beam onto a non-crystallized semiconductor film and which irradiates the non-crystallized semiconductor film with the light beam to crystallize the non-crystallized semiconductor film, the apparatus comprising: a wavefront dividing element which wavefront-divides the incident light beam into a plurality of light beams; and a phase shift mask which has a phase shift portion gives a predetermined phase difference between to light beams from the wavefront driving element and converts the light beams into a light beam having an inverse peak type light intensity distribution, the phase shift portion determining a position of the inverse peak type light intensity distribution where a light intensity is minimized, the wavefront dividing element being positioned on a light path between the optical illumination system and the non-crystallized semiconductor film, the phase shift mask being positioned on the light path between the wavefront dividing element and the non-crystallized semiconductor film, and the wavefront dividing element and the phase shift mask being positioned so that a predetermined region around the phase shift portion is irradiated with the wavefront-divided light beams.