Resist composition, method of forming resist pattern, compound, and acid diffusion control agent

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 base material component (A) whose solubility in a developing solution is changed due to the action of an acid;
• an acid generator component (B) which generates an acid upon exposure;
• and
• a compound (D1) represented by Formula (d1):
• wherein Rb1 and Rb2 each independently represents —COO−, —COOH, or a hydroxyl group, where at least one of Rb1 and Rb2 represents —COO−;
• Rb3, Rb4, and Rb5 each independently represents a hydroxyl group, a halogen atom, an alkyl group which may have a substituent, a fluorinated alkyl group which may have a substituent, or an alkoxy group which may have a substituent;
• Rb6, Rb7, and Rb8 each independently represents an alkyl group, an alkenyl group, an aryl group, a monovalent cyclic aliphatic hydrocarbon group, or a halogen atom, where the alkyl group, the alkenyl group, the aryl group, or the monovalent cyclic aliphatic hydrocarbon group of Rb6, Rb7, and Rb8 may be formed such that some or all hydrogen atoms are substituted with substituents;
• nb3 represents an integer of 0 to 4, nb4 and nb5 each independently represent an integer of 0 to 2, nb6, nb7, and nb8 each independently represent an integer of 0 to 5, and in a case where nb3 to nb8 each independently represent an integer of 2 or greater, a plurality of Rb3's to Rb8's may be the same as or different from one another;
• m represents 1 in a case where only one of Rb1 and Rb2 represents —COO− and represents 2 in a case where both of Rb1 and Rb2 represent —COO−;
• and q represents an integer of 0 to 3.