| 摘要 |
<p>PROBLEM TO BE SOLVED: To remove only a metallic thin film as a black defect of a photomask used for pattering LSI, a liquid crystal or the like with laser light without leaving metallic residue on the photomask and to enhance the transmittance of a substrate forming the photomask. SOLUTION: Laser beam 5 having <=100 picosecond pulse width emitted from a laser beam source 4 capable of repeatedly outputting pulse energy is transferred to the top of a photomask 10 after the radiation width is narrowed by passing through a rectangular variable slit 8 for transfer and a transferred image is moved in the surface of the photomask 10 by moving the position of the variable slit 8 or an XYZ stage 11 with the photomask 10 disposed on the surface while radiating the laser beam to remove a black defective part of the photomask 10.</p> |
