Resist composition and method of forming resist pattern

1. A resist composition generating an acid upon exposure and having solubility in a developing solution, which is changed by action of an acid, the resist composition comprising:

a resin component (A1) having solubility in a developing solution, which is changed by action of an acid,

wherein the resin component (A1) has a constitutional unit (a01) represented by General Formula (a01-1) and a constitutional unit (a02) derived from a compound represented by General Formula (a02-1),

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, Yax 01 represents a single bond or a divalent linking group, Ax represents a sulfonyl group or a sulfoxide group, Raz 01 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a halogenated alkyl group having 1 to 6 carbon atoms, and s0 represents an integer of 0 to 6, and v0 represents an integer of 0 to 6, provided that 1≤s0+v0≤6 and u0≤s0+v0,

wherein W represents a polymerizable group-containing group, Wa x0 represents a cyclic group having an (n ax0 +1)-valent aromaticity, which may have a substituent, Wa x0 may form a condensed ring with W, and n ax0 represents an integer of 1 to 3.

2. The resist composition according to claim 1 , wherein the constitutional unit (a02) is a constitutional unit represented by General Formula (a02-1-1),

wherein R X11 , R X12 , and R X13 each independently 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 a cyclic group having an (n ax1 +1)-valent aromaticity, which may have a substituent, where Ya x1 and Wa x1 may form a condensed ring, or R X11 , Ya x1 , and Wa x1 may form a condensed ring, and n ax1 represents an integer of 1 to 3.

3. The resist composition according to claim 1 , wherein a proportion of the constitutional unit (a01) is in a range of 1% to 50% by mole with respect to a total (100% by mole) of all constitutional units constituting the resin component (A1).

4. The resist composition according to claim 1 , wherein the resist composition further comprises a compound represented by General Formula (d1-1), (d1-2) or (d1-3),

wherein Rd 1 to Rd 4 represent a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, provided that the carbon atom adjacent to the S atom as Rd 2 in General Formula (d1-2) has no fluorine atom bonded thereto; Yd 1 represents a single bond or a divalent linking group; m represents an integer of 1 or greater; and each M m+ independently represents an m-valent organic cation.

5. The resist composition according to claim 1 , wherein in General Formula (a01-1), s0 represents an integer of 0 to 3, and vo represents an integer of 0 to 3, provided that 1≤s0+v0≤3.

6. 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.

7. The method of forming a resist pattern according to claim 6 , wherein the resist film is exposed to an extreme ultraviolet (EUV) ray or an electron beam (EB).