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, 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 coated substrate, comprising:
a photoresist layer on a substrate; and
a topcoat layer on the photoresist layer, wherein the topcoat layer comprises:
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, and
wherein the third resin comprises one or more strong acid groups.
7. The coated substrate of claim 6 , wherein the topcoat layer is a graded layer.
8. 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, and
wherein the third resin comprises one or more strong acid groups; and
(c) exposing the photoresist layer to actinic radiation.
9. The method of claim 8 , wherein the exposure is an immersion exposure and the substrate is a semiconductor wafer.
10. The method of claim 8 , wherein the topcoat layer is a graded layer.