Resist composition and method of forming resist pattern

A resist composition which generates an acid upon exposure and exhibits changed solubility in a developing solution under action of the acid, the resist composition comprising:

• a base component (A) which exhibits changed solubility in a developing solution under action of the acid, and
• a fluorine additive component (F) which exhibits decomposability to an alkali developing solution,
• the base component (A) comprising a resin component (A1) having a structural unit (a1) containing an acid decomposable group that exhibits increased polarity by the action of the acid, and a structural unit (a10) represented by general formula (a10-1) shown below,
• wherein R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• Yax1 represents a single bond or a divalent linking group;
• Wax1 represents an aromatic hydrocarbon group having a valency of (nax1+1);
• and nax1 represents an integer of 1 or more;
• the fluorine additive component (F) comprising a copolymer (F1) having a structural unit (f1) represented by general formula (f1-1) shown below or general formula (f1-2) shown below, and a structural unit (f2) represented by general formula (f2-1) shown below:
• wherein, in formula (f1-1), R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• Raf11 represents a divalent linking group having no acid-dissociable portion;
• Raf12 represents a monovalent organic group;
• —O—Raf12 represents a group capable of being dissociated by the action of a base;
• provided that a hydrocarbon group forming a bridge structure is excluded from Raf11 and Raf12;
• at least one of Raf11 and Raf12 is a group in which part or all of the hydrogen atoms of a hydrocarbon group have been substituted with a fluorine atom;
• and the total number of fluorine atoms within Raf11 and Raf12 is 3 or more;
• in formula (f1-2), R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• Raf13 represents a divalent linking group having no acid-dissociable portion;
• Raf14 represents a monovalent organic group;
• —C(═O)Raf14 represents a group capable of being dissociated by the action of a base;
• provided that a hydrocarbon group forming a bridge structure is excluded from Raf13 and Raf14;
• at least one of Raf13 and Raf14 is a group in which part or all of the hydrogen atoms of a hydrocarbon group have been substituted with a fluorine atom;
• and the total number of fluorine atoms within Raf13 and Raf14 is 3 or more:
• wherein R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• and Raf21 is an acid dissociable group represented by general formula (f2-r-1) or (f2-r-2) shown below:
• wherein, in formula (f2-r-1), Yaf represents a carbon atom;
• Xaf represents a group which forms an aliphatic cyclic group together with Yaf;
• wherein part or all of the hydrogen atoms of the aliphatic cyclic group may be substituted;
• provided that Xaf and Yaf do not form an aliphatic cyclic group having a bridge structure;
• Raf01 to Raf03 each independently represents a hydrogen atom, a monovalent saturated chain hydrocarbon group of 1 to 10 carbon atoms or a monovalent saturated aliphatic cyclic hydrocarbon group of 3 to 20 carbon atoms, provided that part or all of the hydrogen atoms of the saturated chain hydrocarbon or the saturated aliphatic cyclic hydrocarbon may be substituted;
• two or more of Raf01 to Raf03 may be mutually bonded to form a ring structure;
• and * represents a valence bond;
• in formula (f2-r-2), Yaaf represents a carbon atom;
• Xaaf represents a group which forms an aliphatic cyclic group together with Yaaf, wherein part or all of the hydrogen atoms of the aliphatic cyclic group may be substituted;
• provided that Xaaf and Yaaf do not form an aliphatic cyclic group having a bridge structure;
• Raf04 represents an aromatic hydrocarbon group which may have a substituent;
• and * represents a valence bond.