| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a projection mask in which the number of replacement is small, in an equipment for modifying a semiconductor thin film by radiating, on the semiconductor thin film, a laser beam in conformity with an opening pattern formed in the mask. SOLUTION: A laser beam 11 emitted from an excimer laser oscillator 10 is shaped to a pattern of a projection mask 20 through a total reflection mirror 12 and an optical system 13, and then is reductively projected by a lens 14 to be cast on a substrate 17 in a processing chamber 16. By using a material that has a reflectivity of 70% or above with respect to the laser light for the projection mask 20, the durability of the mask against the laser can be increased, and therefore the laser beam can be cast on the mask many times. By inserting an absorption mask 21 to suppress the reflected light returning to the optical system 13 from the projection mask 20, the damage to the optical system 13 can be reduced, which is otherwise caused by using a high reflectivity material as a material for a mask.</p> |
