Radiation-sensitive resin composition

A radiation-sensitive resin composition comprising:

• (A) a resin insoluble or scarcely soluble in alkali, but becomes alkali soluble by the action of an acid, comprising:
• at least one recurring unit selected from the group consisting of a recurring unit (1-1) and a recurring unit (1-2) (excluding the same unit as the recurring unit (1-1)) shown in the following formula (1),
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• wherein R1 represents a hydrogen atom or a methyl group, A1 represents a single bond or a group —X1—COO— (wherein X1 represents a methylene group, a linear or branched alkylene group having 10 or less carbon atoms, or a bridged or non-bridged divalent alicyclic hydrocarbon group having 10 or less carbon atoms), R2 individually represents a linear or branched alkyl group having 1-6 carbon atoms, R3 represents a hydrogen atom, a linear or branched alkyl group having 1-6 carbon atoms, or a linear or branched oxygen-containing organic group having 1-6 carbon atoms, n is 0 or 1, R4 represents a hydrogen atom or a methyl group, A2 represents a single bond or a group —X2—COO— (wherein X2 represents a methylene group, a linear or branched alkylene group having 10 or less carbon atoms, or a bridged or non-bridged divalent alicyclic hydrocarbon group having 10 or less carbon atoms), R5 individually represents a linear or branched alkyl group having 1-4 carbon atoms or a bridged or non-bridged monovalent alicyclic hydrocarbon group having 4-20 carbon atoms, provided that at least one R5 group is a linear or branched alkyl group having 1-4 carbon atoms, or any two R5 groups form, in combination and together with the carbon atoms to which the two R5 groups bond, a bridged or non-bridged divalent alicyclic hydrocarbon group having 4-20 carbon atoms, with the remaining R5 groups being a linear or branched alkyl group having 1-4 carbon atoms, and
• at least one recurring unit having a lactone skeleton selected from the group consisting of a recurring unit (2-1), a recurring unit (2-2), and a recurring unit (2-3) shown in the following formula (2),
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• wherein R6 represents a hydrogen atom or a methyl group, A3 represents a single bond or a group —X3—COO— (wherein X3 represents a methylene group, a linear or branched alkylene group having 10 or less carbon atoms, or abridged or non-bridged divalent alicyclic hydrocarbon group having 10 or less carbon atoms), R7 indicates a linear or branched alkyl group having 1-6 carbon atoms or a linear or branched oxygen-containing organic group having 1-6 carbon atoms, two or more R7 groups, if present, being either the same or different, i is an integer of 0-4, j is 0 or 1, k is an integer of 1-3, R8 represents a hydrogen atom or a methyl group, B is a methylene group, an oxygen atom, or a sulfur atom, R9 represents a hydrogen atom, a linear or branched alkyl group having 1-6 carbon atoms, or a linear or branched oxygen-containing organic group having 1-6 carbon atoms, R10 represents a hydrogen atom or a methyl group, and R11 represents a hydrogen atom, a linear or branched alkyl group having 1-6 carbon atoms, or a linear or branched oxygen-containing organic group having 1-6 carbon atoms, and
• (B) a photoacid generator