Photoresist topcoat compositions and methods of processing photoresist compositions

1. A photoresist topcoat composition, comprising:

a first polymer comprising a first repeat unit of general formula (I) and a second repeat unit of general formula (II):

wherein: R 1 independently represents H, F or optionally fluorinated C1 to C4 alkyl; R2 represents optionally fluorinated linear, branched or cyclic C1 to C20 alkyl; L 1 represents a single bond or a multivalent linking group; and n is an integer of from 1 to 5;

a second polymer comprising a first repeat unit of general formula (III) and a second repeat unit of general formula (IV), wherein the second polymer is free of carboxylic acid groups:

wherein: R 3 independently represents H, F or optionally fluorinated C1 to C4 alkyl; R 4 represents linear, branched or cyclic C1 to C20 alkyl; R 5 represents linear, branched or cyclic C1 to C20 fluoroalkyl; L 2 represents a single bond or a multivalent linking group; and n is an integer of from 1 to 5;

a third polymer comprising a first repeat unit of the general formula (II), a second repeat unit of general formula (V) and a third repeat unit of general formula (VI):

wherein: R 6 independently represents H, F, and optionally fluorinated C1 to C4 alkyl; R 7 represents linear, branched or cyclic C1 to C20 alkyl; and R 8 represents a linear, branched or cyclic C1 to C20 fluoroalkyl; and

a solvent.

2. The photoresist topcoat composition of claim 1 , wherein L 2 represents —C(O)OCH 2 —.

3. The photoresist topcoat composition of claim 1 , wherein the composition comprises a solvent mixture.

4. The photoresist topcoat composition of claim 3 , wherein the solvent mixture comprises: a first organic solvent chosen from C4 to C10 monovalent alcohols; and a second organic solvent represented by general formula (VII):

wherein: R 16 and R 17 are independently chosen from C3 to C8 alkyl; and the total number of carbon atoms in R 16 and R 17 taken together is greater than 6.

5. A coated substrate, comprising:

a photoresist layer on a substrate; and

a topcoat layer formed from a photoresist topcoat composition of claim 1 on the photoresist layer.

6. The coated substrate of claim 5 , wherein L 2 represents —C(O)OCH 2 —.

7. The coated substrate of claim 5 , wherein the composition comprises a solvent mixture.

8. The coated substrate of claim 7 , wherein the solvent mixture comprises: a first organic solvent chosen from C4 to C10 monovalent alcohols; and a second organic solvent represented by general formula (VII):

wherein: R 16 and R 17 are independently chosen from C3 to C8 alkyl; and the total number of carbon atoms in R 16 and R 17 taken together is greater than 6.

9. 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 photoresist topcoat composition of claim 1 to form a topcoat layer;

(c) exposing the topcoat layer and the photoresist layer to activating radiation; and

(d) contacting the exposed topcoat layer and photoresist layer with a developer to form a resist pattern.

10. The method of claim 9 , wherein the topcoat layer is formed by spin-coating, and the second polymer migrates to an upper surface of the topcoat layer during the spin-coating, wherein an upper surface of the topcoat layer consists essentially of the second polymer.

11. The method of claim 9 , wherein L 2 represents —C(O)OCH 2 —.

12. The method of claim 9 , wherein the composition comprises a solvent mixture.

13. The method of claim 12 , wherein the solvent mixture comprises: a first organic solvent chosen from C4 to C10 monovalent alcohols; and a second organic solvent represented by general formula (VII):

wherein: R 16 and R 17 are independently chosen from C3 to C8 alkyl; and the total number of carbon atoms in R 16 and R 17 taken together is greater than 6.