Positive resist composition for immersion exposure and pattern-forming method using the same

A pattern-forming method comprising:

• forming a resist film with a resist composition comprising:
• (A) a resin containing at least one repeating unit having a fluorine atom and increasing a solubility of the resin in an alkali developer by an action of an acid;
• and
• (B) a compound capable of generating an acid upon irradiation with one of an actinic ray and radiation,
• wherein the repeating unit having a fluorine atom contained in resin (A) is at least one repeating unit of Formula (II):
• in formula (II), Rx1, Rx2 and Rx3 each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, an alkyl group, or -L3-C(Rf1)(Rf2)Ra;
• Rf1 and Rf2 each independently represents a hydrogen atom, a fluorine atom or an alkyl group, provided that at least one of Rf1 and Rf2 represents a fluorine atom or a fluoroalkyl group;
• Ra represents a hydrogen atom or a hydroxyl group;
• L3 represents a single bond, an alkylene group, —CH2—O—, or —CH2—COO—;
• R1 and Rm each independently represents a hydrogen atom or an alkyl group;
• Z1 represents a monocyclic cycloalkylene group;
• L1 represents a single bond or a divalent linking group:
• n and q each independently represents 0 or 1;
• r represents an integer of from 1 to 6;
• and Y represents a hydrogen atom or an acid-undecomposable organic group;
• wherein the repeating unit having a fluorine atom contained in resin (A) further includes a repeating unit represented by formula (AI):
• wherein Rb0 represents a hydrogen atom or an unsubstituted alkyl group having from 1 to 4 carbon atoms:
• A′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent linking group obtained by combining these groups;
• and B2 represents a group represented by formulae (V-1) to (V-5):
• in formulae (V-1) to (V-5), R1b, R2b, R3b, R4b and R5b each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxyl group, an alkoxycarbonyl group, an alkylsulfonyl-imino group or an alkenyl group each of which may have a substituent;
• and two of R1b to R5b may be bonded to form a ring;
• and
• further wherein compound (B) is represented by the following formula (ZI):
• wherein R201, R202 and R203 each independently represents an organic group provided that at least one of R201, R202 and R203 represents a phenyl group, and X− represents an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom and which has an alicyclic group;
• exposing the resist film by immersion exposure, so as to form an exposed resist film;
• and
• developing the exposed resist film.