Claims
- 1. An apparatus for providing a purged optical path between an optical source surface and an optical target surface and for permitting relative movement between the optical source surface and the optical target surface, the apparatus comprising:
a body defining first and second opposing surfaces, said first opposing surface being configured for positioning closely adjacent to the optical target surface and said second opposing surface being configured to mate with the optical source surface; a central cavity formed in said body for passing light through said body, said central cavity being open at said first and second opposing surfaces; at least one gas supply bore formed in said body to supply a flow of a purge gas to said central cavity; and at least one gas removal bore formed in said body at said first opposing surface to remove gas from a gap formed between said first opposing surface and said optical target surface.
- 2. The apparatus of claim 1, wherein said optical target surface is a reticle surface, a pellicle surface, or a semiconductor wafer surface.
- 3. The apparatus of claim 1, further comprising a purge plate that surrounds and is co-planar with said optical target surface.
- 4. The apparatus of claim 1, wherein said gap is in the range of 0.002 to 0.02 inches.
- 5. The apparatus of claim 1, comprising a plurality of gas removal bores, wherein said body further comprises an accumulator internal to said body, wherein said accumulator interconnects said plurality of gas removal bores.
- 6. The apparatus of claim 1, wherein said body is substantially cylindrical in shape.
- 7. The apparatus of claim 1, wherein said at least one gas supply bore opens to said central cavity adjacent said second opposing surface.
- 8. The apparatus of claim 1, wherein said opposing first surface and said opposing second surface are substantially parallel.
- 9. The apparatus of claim 1, where said at least one gas removal bore on said first opposing surface is radially closer to said central cavity than to an outer edge of said body to provide a pressure within said central cavity that is lower than a pressure external to said body.
- 10. The apparatus of claim 1, wherein said at least one gas removal bore on said first opposing surface is radially closer to an outer edge of said body than to said central cavity to provide a pressure within said central cavity that is greater than a pressure external to said body.
- 11. A method for providing a purged optical path between an optical source surface and an optical target surface and for permitting relative movement between the optical source surface and the optical target surface, comprising the steps of:
(a) placing a scavenger in the optical path between the optical source surface and the optical target surface, a first opposing surface of said nozzle being positioned closely adjacent said optical target surface and forming a gap therebetween, and a second opposing surface of said nozzle being coupled to said optical source surface; (b) injecting a purge gas into the optical path enclosed by said scavenger; (c) permitting said purge gas to leak into said gap; and (d) removing said purge gas and any ambient air from said gap.
- 12. The method of claim 11, wherein step (d) further comprises the step of:
accumulating said purge gas and any ambient air from said gap prior to removal.
- 13. The method of claim 11, wherein step (d) comprises the step of:
removing said purge gas and any ambient air from said gap through at least one vacuum port in the first opposing surface.
- 14. The method of claim 13, further comprising the step of:
(e) positioning said at least one vacuum port on said first opposing surface to achieve a desired pressure within said nozzle.
Parent Case Info
[0001] This application claims the benefit of U.S. Provisional Application No. 60/201,704, filed May 3, 2000.
Provisional Applications (1)
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Number |
Date |
Country |
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60201704 |
May 2000 |
US |