Laser irradiation method, laser irradiation apparatus, and method for manufacturing semiconductor device

摘要

In a process to manufacture a semiconductor device, when a CW laser beam is shaped into linear and is irradiated on a semiconductor film while scanning, a plurality of crystal grains extended long in the scanning direction are formed. The semiconductor thus formed has a characteristic similar to that of single-crystal substantially in the scanning direction. However, the output of a CW laser oscillator is so low that it takes much time to anneal and the design rule is also very restricted. By operating a zoom function, a size of the linear laser beam can be changed in accordance with a size of a semiconductor element formed on a semiconductor element, the time required for laser annealing can be shortened, and the restriction of the design rule can be eased. The zoom function includes a zoom function that is continuously changeable (refer to FIG. 1A to 2C) and that can change the length of the linear laser beam into several pattern (refer to FIG. 6A, 6B, and 6C).