APPARATUS FOR PHOTOMASK REPAIR

摘要

An apparatus for repairing both clear and opaque defects in a photomask having a metal film pattern on a glass plate in which a visible laser light source is pulsed at selected frequencies to direct an optically focused laser beam into a gas sealed cell containing a mask. At one frequency, the laser pulses ablate opaque mask defects. At another frequency, and with the cell filled with a metal bearing gas, the laser beam causes thermal decomposition of the gas and deposition of metal to cure clear defects.