Pattern forming method, actinic-ray-sensitive or radiation-sensitive resin composition, and resist film

A pattern forming method comprising:

• (1) forming a film by using an actinic-ray-sensitive or radiation-sensitive resin composition containing a resin that includes;
• 65 mol % or more of a repeating unit represented by the following General Formula (AI) as a repeating unit having a group which generates a polar group by being degraded by the action of an acid based on all repeating units in the resin, and
• at least one kind of repeating unit represented by the following General Formula (I) or (II);
• (2) exposing the film;
• and
• (3) developing the exposed film using a developer that contains an organic solvent:
• wherein in General Formula (AI),
• Xa1 represents a hydrogen atom, a methyl group which may have a substituent, or a group represented by —CH2—R9, where R9 represents a hydrogen atom or a monovalent organic group;
• T represents a single bond;
• and
• each of Rx1 to Rx3 independently represents an alkyl group or a cycloalkyl group;
• and two or more of Rx1 to Rx3 may form a cycloalkyl group by binding to each other,
• wherein in General Formulae (I) and (II),
• each of R11 and R21 independently represents a hydrogen atom or an alkyl group;
• each of R12 and R22 independently represents an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, a carboxyl group, a halogen atom, a hydroxyl group, or a cyano group;
• each of R13 and R23 independently represents an alkylene group, a cycloalkylene group, or a combination thereof, provided that when a plurality of R13s are present, each R13 may be the same as or different from each other, and provided that when a plurality of R23s are present, each R23 may be the same as or different from each other;
• each of Y1 and Y2 independently represents a single bond, an ether bond, an ester bond, an amide bond, a urethane bond, or a ureylene bond, provided that when a plurality of Y1s are present, each Y1 may be the same as or different from each other, and provided that when a plurality of Y2s are present, each Y2 may be the same as or different from each other;
• each of X1 and X2 independently represents a methylene group, a methyl methylene group, a dimethyl methylene group, an ethylene group, an oxygen atom, or a sulfur atom,
• each of m1 and m2 independently represents an integer of 0 to 4;
• each of n1 and n2 independently represents an integer of 0 to 4, provided that when n1 is 2 or greater, a plurality of R12s may be the same as or different from each other or may form a ring by binding to each other, and provided that when n2 is 2 or greater, a plurality of R22s may be the same as or different from each other or may form a ring by binding to each other.