RESIN COMPOSITION, RESIST PATTERN-FORMING METHOD AND POLYMER

1 . A resin composition comprising:

a polymer comprising a structural unit that comprises a group represented by formula (1); and

a solvent,

wherein, in the formula (1),

R 1 to R 4 each independently represent a hydrogen atom, a fluorine atom or a monovalent organic group having 1 to 20 carbon atoms, wherein at least one of R 1 to R 4 represents the fluorine atom or a group comprising the fluorine atom;

R 5 represents a substituted or unsubstituted trivalent chain hydrocarbon group having 1 to 7 carbon atoms; and

* denotes a binding site to other moiety of the structural unit.

2 . The resin composition according to claim 1 , wherein the structural unit is represented by any one of formulae (2-1) to (2-3):

wherein, in the formulae (2-1) to (2-3), Z represents the group represented by the formula (1),

wherein, in the formula (2-1), R 6 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group,

wherein, in the formula (2-2),

R 7 represents a hydrogen atom or a methyl group;

R 8 , R 9 and R 10 each independently represent a hydrogen atom, a halogen atom, a hydroxy group or a monovalent organic group having 1 to 20 carbon atoms, or at least two of one or a plurality of R 8 (s) and one or a plurality of R 9 (s) and R 10 optionally taken together represent a ring structure having 3 to 20 ring atoms;

a is an integer of 1 to 4,

wherein in a case where a is no less than 2, a plurality of R 8 s are identical or different with each other, and a plurality of R 9 s are identical or different with each other; and

L represents a single bond or a divalent linking group, wherein R 10 and L optionally taken together represent a ring structure having 3 to 20 ring atoms, together with the carbon atom to which R 10 and L bond, and

wherein, in the formula (2-3),

R 11 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; and E represents a single bond or a divalent linking group.

3 . The resin composition according to claim 1 , wherein the group comprising the fluorine atom is a group represented by formula (a):

wherein, in the formula (a), R a and R b each independently represent a hydrogen atom, a fluorine atom or a monovalent organic group having 1 to 19 carbon atoms.

4 . The resin composition according to claim 1 , wherein in the formula (1), at least one of R 3 and R 4 comprises —COO—.

5 . The resin composition according to claim 1 , further comprising a radiation-sensitive acid generator.

6 . The resin composition according to claim 5 , further comprising a polymer comprising a structural unit that comprises an acid-labile group, and having a lower percentage content of fluorine atoms than a percentage content of fluorine atoms of the polymer comprising the structural unit that comprises the group represented by the formula (1).

7 . A laminate structure comprising:

a resist film; and

a protective film which is a cured product of the resin composition according to claim 1 , and which is overlaid on the resist film.

8 . A resist pattern-forming method comprising:

applying the resin composition according to claim 5 directly or indirectly on a substrate to form a resist film;

exposing the resist film; and

developing the resist film exposed.

9 . A resist pattern-forming method comprising:

forming a resist film;

applying the resin composition according to claim 1 on the resist film to form a protective film overlaid on the resist film;

subjecting the resist film having the protective film overlaid thereon to liquid immersion lithography; and

developing the resist film subjected to the liquid immersion lithography.

10 . A polymer comprising a structural unit that comprises a group represented by formula (1):

wherein, in the formula (1),

R 1 to R 4 each independently represent a hydrogen atom, a fluorine atom or a monovalent organic group having 1 to 20 carbon atoms, wherein at least one of R 1 to R 4 represents the fluorine atom or a group comprising the fluorine atom;

R 5 represents a substituted or unsubstituted trivalent chain hydrocarbon group having 1 to 7 carbon atoms; and

* denotes a binding site to other moiety of the structural unit.