Beam homogenizer, laser irradiation apparatus, laser irradiation method, and method of manufacturing semiconductor device

摘要

There is disclosed a technique in which stripe formation due to laser annealing is prevented and uniform laser annealing is made over the whole surface of a substrate. A laser beam having an energy distribution with an edge which has a nearly vertical shape is used, and when scanning of the laser beam is carried out, the scanning is carried out while the edge having the nearly vertical shape is made the front of the scanning.