| 摘要 |
<p>In a projecting printing system for forming an image on a radiation sensitive wafer, which system includes a mask having a transparent substrate with a pattern of opaque and transparent areas formed on the surface thereof, an illumination system for directing radiation through the mask to the radiation sensitive wafer, an optical system for forming a focused image of a mask pattern on the wafer, the improvement comprising a pellicle cover assembly for maintaining the images of any contaminate particles on the surface of the mask out of focus, said pellicle cover being fabricated from polymethylmethacrylate.</p> |
