Fractionated novolak resin and photoresist composition therefrom
AssigneeClariant Finance (BVI) Limited
InventorsM. Dalil Rahman, Ping-Hung Lu
Life of this patent
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Abstract
The present invention provides a method for producing a film forming, fractionated novolak resin having consistent molecular weight and superior performance in photoresist composition, by isolating such novolak resin fractions without high temperature distillation. A method is also provided for producing photoresist composition from such a fractionated novolak resin and for producing semiconductor devices using such a photoresist composition.
Claims8
A method for producing a positive photoresist composition having superior lithographic performance comprising:
- a) condensing formaldehyde with one or more phenolic compounds, in the presence of an acid catalyst and thereby producing a novolak resin polymeric condensation product;
- b) adding a water soluble organic polar solvent and water to the novolak resin reaction mixture, thereby precipitating the novolak resin polymeric condensation product, and then removing the remaining solution;
- c) adding a water soluble organic polar solvent and water to the precipitate of step b), and thereby again precipitating the novolak resin condensation product, and removing the remaining solution of step c);
- d) dissolving the novolak resin polymeric condensation product in a photoresist solvent and thereby forming a solution, then removing any remaining water and water soluble organic polar solvent, thereby producing a film forming, fractionated novolak resin solution;
- and
- e) providing an admixture of:
- 1) a photosensitive component in an amount sufficient to photosensitive a photoresist composition;
- 2) the film forming novolak resin from step d);
- and 3) additional photoresist solvent, and thereby forming a photoresist composition.
A method for producing a semiconductor device by producing a photo-image on a substrate by coating a suitable substrate with a positive working photoresist composition comprising:
- a) condensing formaldehyde with one or more phenolic compounds, in the presence of an acid catalyst, and thereby producing a novolak resin polymeric condensation product;
- b) adding a water soluble organic polar solvent and water to the novolak resin reaction mixture, thereby precipitating the novolak resin polymeric condensation product, and then removing the remaining solution;
- c) adding a water soluble organic polar solvent and water to the precipitate of step b), and then removing the remaining solution of step c);
- d) dissolving the novolak resin polymeric condensation product precipitate of step c) in a photoresist solvent, then removing any remaining water and water soluble organic polar solvent, and thereby producing a film forming, fractionated novolak resin solution;
- e) providing an admixture of:
- 1) a photosensitive component in an amount sufficient to photosensitize a photoresist composition;
- 2) the film forming novolak resin solution from step d);
- and 3) additional photoresist solvent, and thereby forming a photoresist composition;
- f) coating a suitable substrate with the photoresist composition of step e);
- g) heat treating the coated substrate of step f) until substantially all of the photoresist solvent is removed;
- image-wise exposing the photosensitive composition and removing the image-wise exposed areas of such composition with a suitable developer.
Dependencies are inferred from the claim text.