Laser irradiation method, laser irradiation apparatus, and method of manufacturing a semiconductor device

摘要

Attenuation regions of laser light are removed or reduced in size using a slit located in the immediate vicinity of a surface to be irradiated so that a steep energy distribution is obtained in the end portions of the laser light. The reason why the slit is located in the immediate vicinity of the surface to be irradiated is to suppress the spread of the laser light. In addition, the attenuation regions of the laser light are folded by using a mirror instead of the slit to increase energy densities in the attenuation regions by one another so that a steep energy density distribution is obtained in the end portions of the laser light.