Positive resist composition for forming thick-film resist, thick-film resist laminate, and method of forming resist pattern

A positive resist composition for forming a thick-film resist having a film thickness of 1 to 15 μm, said composition comprising:

• a resin component (A) that comprises acid dissociable, dissolution inhibiting groups and exhibits increased alkali solubility under action of acid, an acid generator component (B) that generates acid upon exposure, a nitrogen-containing organic compound (D), and a dissolution inhibitor which is a cross-linking polyvinyl ether compound, wherein
• said resin component (A) is a polymer compound (A1) with a weight average molecular weight of 20,000 to 50,000, comprising a structural unit (a1) derived from a hydroxystyrene, and a structural unit (a2) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group,
• said acid generator component (B) comprises an onium salt-based acid generator having an anion moiety represented by a general formula (I):
• R4″SO3− (wherein, R4″ represents a linear or branched alkyl group of 4 carbon atoms, or a linear or branched fluoroalkyl group of 4 carbon atoms), wherein said onium salt-based acid generator comprises an acid generator (b-0) represented by general formula (b-0) shown below:
• [wherein, R51 represents a linear or branched alkyl group or fluoroalkyl group of 4 carbon atoms;
• R52 represents a hydrogen atom, a hydroxyl group, a halogen atom, a linear or branched alkyl group, a linear or branched haloalkyl group, or a linear or branched alkoxy group;
• R53 represents an aryl group that may include a substituent group;
• and u″ represents an integer from 1 to 3], and
• said nitrogen-containing organic compound (D) comprises a chain-like tertiary aliphatic amine.