Polymer compositions having photoacid generators and photoresists

1 . A polymer composition comprising:

0.5 to 99 mol % of a hydroxystyrene repeat unit having the formula (A):

0.5 to 99 mol % of a sulfonated photoacid generator repeat unit having the formula (B):

and

0.5 to 99 mol % of an acid labile repeat unit having the formula (C):

wherein:

each of R 1 , R 2 , and R 3 independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group;

R 4 represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a cyano group, and m represents an integer in a range of from 1 to 4, wherein when m is 2 or more, each R 4 independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a cyano group;

each of Q 1 and Q 2 independently represents a hydrogen atom, a fluorine atom or a perfluoro alkyl group with 1 to 4 carbon atoms, and n represents an integer in a range of from 0 to 4, wherein when n is 2 or more, each Q 1 and Q 2 independently represents a hydrogen atom, a fluorine atom or a perfluoro alkyl group with 1 to 4 carbon atoms;

L 1 represents a single bond or a divalent saturated hydrocarbon group having from 1 to 20 carbon atoms, wherein one or more methylene groups in the divalent saturated hydrocarbon group is replaced by an oxygen, a sulfur, a carbonyl group, or a sulfonyl group;

Z + represents an organic cation; and

G 1 represents an organic group comprising an acid labile group, wherein the acid labile repeat unit having the formula (C) is derived from an acrylate having an acid-labile group in its side chain or a methacrylate having an acid-labile group in its side chain.

2 . The polymer composition of claim 1 , wherein the hydroxystyrene repeat unit having the formula (A) is derived from 4-hydroxystyrene.

3 . The polymer composition of claim 2 , wherein the sulfonated photoacid generator repeat unit having the formula (B) is given by:

4 . The polymer composition of claim 1 , wherein the organic cation of Z + is selected from the group consisting of sulfonium cations and iodonium cations.

5 . The polymer composition of claim 1 , further comprising 0 to 98.5 mol % of a repeat unit having the formula (D) not containing an acid labile group:

wherein:

R 5 represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group; and

G 2 represents an organic group not containing an acid labile group.

6 . The polymer composition of claim 5 , wherein the repeat unit having the formula (D) not containing an acid labile group is derived from a styrene, an acrylate or a methacrylate.

7 . A photoresist composition comprising the polymer composition of claim 1 .

8 . The photoresist composition of claim 7 , wherein the photoresist composition is an EUV photoresist or a KrF photoresist.