Radiation-sensitive resin composition and polymer

A polymer comprising:

• at least one repeating unit (i) selected from a repeating unit shown by a formula (1), a repeating unit shown by a formula (2), and a repeating unit shown by a formula (3);
• a repeating unit (ii) shown by a formula (4);
• at least one repeating unit (iii) selected from a repeating unit shown by a formula (5) and a repeating unit shown by a formula (6);
• and
• an acid-dissociable group-containing repeating unit shown by a formula (7),
• the polymer having a polystyrene-reduced weight average molecular weight determined by gel permeation chromatography of 3000 to 100,000,
• wherein p is an integer from 0 to3, q is an integer from 1 to 3, a sum of p and q is equal to or less than 5, R1 represents a hydrogen atom or a methyl group, each R2 independently represents one of a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, and an alicyclic hydrocarbon group having 3 to 25 carbon atoms, and each R2 is a same as or different from each other when p is 2 or 3,
• wherein R3 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, each Rf independently represents one of a fluorine atom and a linear or branched perfluoroalkyl group having 1 to 10 carbon atoms, each Rf is a same as or different from each other, A represents an ester bond or a single bond, G represents an alkylene group having 1 to 5 carbon atoms or a divalent alicyclic hydrocarbon group having 6 to 10 carbon atoms, M+represents a metal ion or a monovalent onium cation, and n is an integer from 1 to 8,
• wherein r is an integer equal to or larger than 0, s is an integer equal to or larger than 1, a sum of r and s is equal to or less than 5, each of R6 to R″ represents a hydrogen atom or a fluorine atom and at least one of R6 to R11 represents a fluorine atom, R12 represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms, R4 represents a hydrogen atom or a methyl group, each R5 independently represents one of a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, and an alicyclic hydrocarbon group having 3 to 25 carbon atoms, each R5 is a same as or different from each other when r is 2 or more, R13 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and B represents a linear, branched, or cyclic divalent hydrocarbon group having 1 to 40 carbon atoms,
• wherein R14 represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and X represents an acid-dissociable group including an alicyclic skeleton having 3 to 25 carbon atoms.