Radiation-sensitive resin composition and resist pattern-forming method

A resist pattern-forming method comprising:

• applying a radiation-sensitive resin composition directly or indirectly on a substrate to form a resist film;
• exposing the resist film;
• and
• developing the resist film exposed, wherein
• the radiation-sensitive resin composition comprises:
• a polymer comprising a first structural unit represented by at least one formula selected from the group consisting of formula (I-1), formula (I-2), formula (I-3), formula (I-4), formula (I-5), formula (I-6), formula (I-7), formula (I-8), formula (I-9), formula (I-10), formula (I-11), formula (I-12), formula (I-13), and formula (I-14) and a second structural unit comprising an acid-labile group which is dissociated by an action of an acid to give a carboxy group;
• a first compound represented by formula (1-1) or formula (1-2);
• and
• a second compound represented by formula (2);
• wherein
• in each of the formulae (I-1) to (I-14), RP represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group,
• wherein
• in each of the formula (1-1) and the formula (1-2), A−represents a monovalent sulfonic acid anion,
• in the formula (1-1), a is an integer of 0 to 11, b is an integer of 0 to 4, and c is an integer of 0 to 4, wherein a sum of a, b, and c is no less than 1;
• R1, R2, and R3 each independently represent a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms, wherein at least one of Re, R2, and R3 represents a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms, in a case in which a is no less than 2, a plurality of R1s are identical or different, in a case in which b is no less than 2, a plurality of R2s are identical or different, and in a case in which c is no less than 2, a plurality of R3s are identical or different;
• n1 is 0 or 1;
• and R4 and R5 each independently represent a hydrogen atom, a fluorine atom, or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms, or R4 and R5 taken together represent a single bond,
• in the formula (1-2), d is an integer of 1 to 11 and e is an integer of 0 to 10, wherein in a case in which d is 1, R6 represents a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms, and in a case in which d is no less than 2, a plurality of R6s are identical or different, and each R6 represents a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms, wherein at least one of the plurality of R6s represents a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms;
• R7 represents a hydroxy group, a nitro group, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms, wherein in a case in which e is no less than 2, a plurality of R7s are identical or different;
• R8 represents a single bond or a divalent organic group having 1 to 20 carbon atoms;
• nz is 0 or 1;
• and n3 is an integer of 0 to 3, and
• R9—COO−X+ (2)
• in the formula (2), R9 represents a monovalent organic group having 1 to 30 carbon atoms;
• and X+ represents a monovalent radiation-sensitive onium cation, and wherein a molar amount of the first structural unit relative to a total molar amount of structural units constituting the polymer is 25 mol % or more, and a molar amount of the second structural unit relative to the total molar amount of the structural units constituting the polymer is 30 mol % or more.