Process for purifying photoresist composition employing a filter sheet
OwnerKenneth C. Hou, Eugene A. Ostreicher +1inventors
InventorsKenneth C. Hou, Eugene A. Ostreicher, Richard D. Sale
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Abstract
A filter sheet is provided which comprises a self-supporting fibrous matrix having immobilized therein particulate filter aid and particulate ion exchange resin, wherein said particulate filter aid and particulate ion exchange resin are distributed substantially uniformly throughout a cross-section of said matrix. A process for removing ionic impurities from a photoresist solution is also provided which comprises passing the photoresist solution through said filter sheet to remove ionic impurities therefrom.
Claims16
A process for removing dissolved ionic impurities from a photoresist composition which comprises passing the photoresist composition through a filter sheet comprising a self-supporting cellulose fiber matrix containing a major amount of normal cellulose pulp possessing a Canadian Standard Freeness of +400 to +800 mL and a minor amount of highly refined pulp possessing a Canadian Standard Freeness of +100 to −1000 mL, said matrix having immobilized therein particulate cation exchange resin and particulate filter aid, wherein the particulate cation exchange resin and particulate filter aid are distributed substantially uniformly throughout a cross-section of the cellulose fiber matrix.
Dependencies are inferred from the claim text.