Apparatus for recycling alkane immersion liquids and methods of employment
OwnerDouglas Adelman, Roger French +4inventors
InventorsDouglas Adelman, Roger French, Michael Lemon, Sheng Peng, Aaron Shoe, Robert Wheland
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Abstract
The present invention provides a clean closed loop fluid transport system and methods for recycling low absorbance liquid alkanes. The alkanes can be advantageously employed as immersion liquids in the production of electronic or integrated optical circuit elements by photolithographic methods employing ultraviolet wavelengths.
Claims45
An apparatus comprising:
- a clean closed loop fluid transport system comprising an adsorbent segment;
- a filtration segment;
- a photo-imaging segment having a point of entry;
- tubes disposed to connect said segments;
- a pump disposed to cause a fluid to flow through said tubes to and from said segments;
- a means for delivering and removing a fluid to and from said photo-imaging segment;
- and a liquid alkane contained within the apparatus, wherein at the point of entry of the photo-imaging segment thereof said liquid alkane has an absorbance at 193 nm of less than 0.40 cm−1.
A method for performing liquid immersion photolithography comprising:
- providing a clean closed loop fluid transport system comprising an adsorbent segment, a filtration segment, a photo-imaging segment, tubes disposed to connect said segments, a pump disposed to cause a fluid to flow within the system, a means for delivering and removing a fluid to and from said photo-imaging segment;
- and a means for purging absorbed gas from a fluid;
- causing a liquid alkane having an absorbance at 193 nm of <0.40 cm−1 to be introduced into the photo-imaging segment;
- disposing the liquid alkane between a light source and a surface undergoing imagewise illumination by the light source;
- causing the liquid alkane to flow from the photo-imaging segment to the adsorbent segment through the tubes;
- optionally deoxygenating the liquid alkane by purging absorbed oxygen from the liquid alkane;
- contacting the liquid alkane with an adsorbent, the contacted liquid alkane after said contacting having an absorbance at 193 nm of <0.40 cm−1;
- and causing the contacted liquid alkane to flow from the adsorbent segment to said photo-imaging segment.
A method for cleaning a metal surface, comprising contacting the metal surface with elemental fluorine gas for a period of 1 to 48 hours, such that later contact of an immersion liquid with the cleaned metal surface increases the A/cm of said liquid by less than 0.02 cm−1.
A method of cleaning a metal surface, consisting of heating the metal surface, to 350-500° C., in air for a period of 4 to 24 hours, such that later contact of an immersion liquid with that surface increases the A/cm of said fluid by <0.02 cm−1,
Dependencies are inferred from the claim text.