Contact cooling of a projection mask.

摘要

An apparatus and method for cooling a large-area, pass-through projection mask (14) for excimer ablation. In a preferred embodiment, a laser-transparent window (12) is spaced apart from the projection mask to provide a thermal escape path (26). The thermal escape path receives a liquid flow which is in direct contact with patterned masking material (18) of the projection mask. The liquid, preferably deionized water, is caused to flow in a laminar fashion. The liquid intersects the laser energy (10) of the excimer laser. In a second embodiment, the liquid flow is along the periphery of the patterned masking material.