BEAM HOMOGENIZER, LASER IRRADIATION SYSTEM, AND SEMICONDUCTOR DEVICE PRODUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To solve the problem of change in energy distribution of a beam spot on an irradiated surface at change in laser emission condition or at the case before and after maintenance. SOLUTION: In an optical system for forming a rectangular beam spot, an optical system that unifies longitudinal or lateral energy distribution of a rectangular beam spot on an irradiated surface is replaced by an optical element having a curved surface pattern on an injection side face of a laser beam and two reflective faces opposed to each other. The injection side face is a surface forming the optical element, and defined as a surface that is disposed at an injection side of the laser beam, through which the laser beam injects into the optical element. COPYRIGHT: (C)2005,JPO&NCIPI