LASER-BASED SYSTEM FOR THE TOTAL REPAIR OF PHOTOMASKS

摘要

A low power laser-based system for repairing clear and opaque defects in a photomask. The system includes a laser source for providing a beam having a wavelength between 0.40 mu m and 2.0 mu m. The beam is coupled to a computer controlled scanning device which scans the beam across a defective area of the photomask to repair the defect by thermal deposition of micron-size films on the defect or by laser-induced degradation of a polymer coating the defect. Excess metal is removed from the photomask surface via laser vaporization.