Resist composition and method of forming resist pattern

1. A resist composition which generates an acid upon exposure and whose solubility in a developing solution is changed due to an action of the acid, the resist composition comprising:

a resin component (A1) whose solubility in a developing solution is changed due to the action of the acid,

wherein the resin component (A1) has a constitutional unit derived from a compound represented by Formula (a0-1) a constitutional unit derived from a compound represented by Formula (a0-2) and a constitutional unit represented by Formula (a10-1),

wherein the proportion of the constitutional unit derived from a compound represented by Formula (a0-1) in the resin component (A1) is in a range of 5% to 60% by mole with respect to 100% by mole of the total of the constitutional unit derived from a compound represented by Formula (a0-1), the constitutional unit derived from a compound represented by Formula (a0-2) and constitutional unit represented by Formula (a10-1),

wherein the proportion of the constitutional unit derived from a compound represented by Formula (a0-2) in the resin component (A1) is in a range of 1% to 55% by mole with respect to 100% by mole of the total of the constitutional unit derived from a compound represented by Formula (a0-1), the constitutional unit derived from a compound represented by Formula (a0-2) and the constitutional unit derived from a compound represented by Formula (a10-1), and

wherein the proportion of the constitutional unit represented by Formula (a10-1) in the resin component (A1) is in a range of 20% to 80% by mole with respect to 100% by mole of the total of the constitutional unit derived from a compound represented by Formula (a0-1), the constitutional unit derived from a compound represented by Formula (a0-2) and the constitutional unit represented by Formula (a10-1):

wherein W represents a polymerizable group-containing group, and Ra 01 represents an acid dissociable group represented by Formula (a01-r-1) or (a01-r-2):

wherein Ra 011 to Ra 013 each independently represents an unsubstituted linear or branched aliphatic hydrocarbon group, Ra 014 represents a linear aliphatic hydrocarbon group, Ra 015 represents a group that forms a monocyclic aliphatic cyclic group together with a carbon atom to which Ra 014 is bonded, and the symbol “*” represents a bonding site;

wherein W represents a polymerizable group-containing group, and Ra 02 represents an acid dissociable group represented by Formula (a02-r-1):

wherein Ra 021 and Ra 022 each independently represents a linear or branched aliphatic hydrocarbon group, Ra 023 represents a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, or a group in which one hydrogen atom has been removed from benzene, naphthalene, anthracene, phenanthrene, biphenyl, fluorene, pyridine or thiophene, and the symbol “*” represents a bonding site

wherein R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Ya x1 represents a single bond or a divalent linking group, Wa x1 represents an (n ax1 +1)-valent aromatic hydrocarbon group, and n ax1 represents an integer of 1 or greater.

2. A method of forming a resist pattern, comprising:

forming a resist film on a support using the resist composition according to claim 1 ;

exposing the resist film; and

developing the exposed resist film to form a resist pattern.

3. The method of forming a resist pattern according to claim 2 , wherein exposing the resist film comprises exposing the resist film to extreme ultraviolet rays (EUV) or electron beams (EB).