Claims
- 1. An apparatus for enabling cleaning of a resist outgassing window in a lithographic tool, comprising:a chamber of electrically conductive material and having an opening at one end, a resist outgassing window mounted in said chamber opposite said opening, at least a pair of spaced electrodes mounted in said chamber, means for supplying a gas into said chamber, means for producing a vacuum external of said chamber, means for applying a potential to said chamber, and means for applying a voltage to said pair of spaced electrodes to create ions from the supplied gas.
- 2. The apparatus of claim 1, additionally including a filament mounted in said chamber and connected to a power supply.
- 3. The apparatus of claim 1, wherein said filament is connected to one of said electrodes.
- 4. The apparatus of claim 1, wherein said pair of spaced electrodes comprise cylindrical sectors.
- 5. The apparatus of claim 4, wherein said spaced cylindrical sector electrodes subtend about 175 degrees.
- 6. The apparatus of claim 1, additionally including a pair of spaced x-y deflecting electrodes mounted within said chamber adjacent said window.
- 7. The apparatus of claim 6, wherein said spaced x-y deflecting electrodes are of cylindrical configuration.
- 8. The apparatus of claim 1, wherein said chamber is mounted in a conductance limiting structure.
- 9. The apparatus of claim 1, in combination with a resist-coated wafer mounted external of and adjacent to said opening in said chamber, and a radiation source for directing radiation through said window, said chamber, and said opening onto said resist-coated wafer.
- 10. A method for cleaning a resist outgassing window, comprising: providing a chamber of conductive material having an opening therein and a resist outgassing window mounted opposite the opening, providing spaced electrodes within the chamber, supplying a gas under pressure into the chamber, applying a voltage to the spaced electrodes, applying a voltage to the chamber different from the voltage to the electrodes, and creating ions from the supplied gas by applying the voltage to the electrodes and chamber causing cleaning of an inner surface of the resist outgassing window.
- 11. The method of claim 10, additionally including maintaining the electrodes at the same voltage, and wherein supplying a gas under pressure is carried out by supplying a gas selected from the group consisting of argon, oxygen, neon, and krypton.
- 12. The method of claim 10, additionally including maintaining the electrodes at the same voltage, and wherein supplying a gas under pressure is carried out by supplying an inert gas.
- 13. The method of claim 11, wherein the electrodes are maintained at a voltage of about −100 to −500 volts, and the chamber is maintained at about 0 volts.
- 14. The method of claim 11, wherein the gas under pressure is maintained at about 200 mTorr.
- 15. The method of claim 10, additionally including providing a filament within the chamber, and heating the filament to a point of thermionic emission, and applying a different voltage to each of the spaced electrodes.
- 16. The method of claim 15, wherein supplying a gas under pressure is carried out by supplying CO2 at about 100 mTorr.
- 17. The method of claim 15, wherein the filament is fabricated from material selected from the group consisting of thoriated iridium, thoriated indium, tungsten, and molybdenum.
- 18. The method of claim 15, wherein the filament is fabricated from a thermionic emitter material.
- 19. The method of claim 15, wherein the voltage applied to the spaced electrodes differs by about 25 volts.
- 20. The method of claim 15, wherein an electron collection current at one of the spaced electrodes is about 10 mA.
- 21. The method of claim 15, additionally including electrically connecting the filament to one of the spaced electrodes.
- 22. The method of claim 10, additionally including forming a pressure differential across the opening in the chamber.
- 23. The method of claim 10, additionally including providing a conductance limiting structure about the chamber.
Government Interests
The United States Government has rights in this invention pursuant to Contract No. DE-AC04-94AL85000 between the United States Department of Energy and the Sandia Corporation for the operation of the Sandia National Laboratories.
US Referenced Citations (5)
Number |
Name |
Date |
Kind |
5003178 |
Livesay |
Mar 1991 |
|
5714306 |
Komatsu et al. |
Feb 1998 |
|
5863706 |
Komatsu et al. |
Jan 1999 |
|
5932966 |
Schneider et al. |
Aug 1999 |
|
6031598 |
Tichenor et al. |
Feb 2000 |
|