| abstract |
The present invention provides an efficient heat treatment such as activation treatment of impurities on a substrate such as a thick silicon wafer with large heat capacity by laser annealing. n Provided is a laser annealing apparatus 1 for heat-treating a surface of a substrate 30 comprising: a pulse oscillation laser source 10 which generates a pulse laser with gentle rise time and long pulse width; a continuous wave laser source 20 which generates a near-infrared laser for assisting annealing; optical systems 12, 22 which shape and guide beams 15, 25 of the two types of lasers respectively so as to irradiate the surface of the substrate 30 therewith; and a moving device 3 which moves the substrate 30 relatively to the laser beams 15, 25 to allow scanning of the combined irradiation of the two types of laser beams. According to this apparatus, deep activation of impurities can be performed in a thick semiconductor substrate with large heat capacity while securing sufficient light penetration depth and thermal diffusion length therefor. |