Compositions and processes for photolithography
View Patent ↗Topcoat layer compositions are provided that are applied above a photoresist composition. The compositions find particular applicability to immersion lithography processing.
1. A composition suitable for use in forming a topcoat layer over a layer of photoresist, the composition comprising:
a first resin, a second resin and a third resin which are different from each other,
wherein the first resin comprises one or more fluorinated groups and is present in the composition in a larger proportion by weight than the second and third resins individually,
wherein the second resin has a lower surface energy than a surface energy of the first resin and the third resin,
wherein the second resin is substantially immiscible with the first resin, and
wherein the third resin comprises one or more strong acid groups.
2. The composition of claim 1 , wherein the first resin further comprises a sulfonamide.
3. The composition of claim 1 , wherein the second resin comprises one or more photoacid-labile groups.
4. The composition of claim 1 , wherein the one or more strong acid groups of the third resin comprise a sulfonic acid group.
5. The composition of claim 1 , further comprising a solvent system comprising a mixture of: an alcohol; an alkyl ether and/or an alkane; and a dialkyl glycol mono-alkyl ether.
6. A method of processing a photoresist composition, comprising:
(a) applying a photoresist composition over a substrate to form a photoresist layer;
(b) applying over the photoresist layer a topcoat composition, the composition comprising:
a first resin, a second resin and a third resin which are different from each other,
wherein the first resin comprises one or more fluorinated groups and is present in the composition in a larger proportion by weight than the second and third resins individually,
wherein the second resin has a lower surface energy than a surface energy of the first resin and the third resin,
wherein the second resin is substantially immiscible with the first resin, and
wherein the third resin comprises one or more strong acid groups; and
(c) exposing the photoresist layer to actinic radiation.
7. The method of claim 6 , wherein the exposure is an immersion exposure and the substrate is a semiconductor wafer.
8. The method of claim 6 , wherein the first resin further comprises a sulfonamide.
9. The method of claim 6 , wherein the second resin comprises one or more photoacid-labile groups.
10. The method of claim 6 , wherein the one or more strong acid groups of the third resin comprise a sulfonic acid group.
11. The method of claim 6 , further comprising a solvent system comprising a mixture of: an alcohol; an alkyl ether and/or an alkane; and a dialkyl glycol mono-alkyl ether.