Patent ID: 8865389

Claim:
An actinic-ray- or radiation-sensitive resin composition comprising a resin comprising a repeating unit (A), the a repeating unit (A) containing a structural moiety (S1) that when acted on by an acid, is decomposed to thereby generate an alkali-soluble group and a structural moiety (S2) that when acted on by an alkali developer, is decomposed to thereby increase its rate of dissolution in the alkali developer, and a repeating unit (B) that when exposed to actinic rays or radiation, generates an acid, wherein the repeating unit (A) has a structure expressed by general formula (1α) below, in which R 3 , when k≧2 each independently, represents an alkyl group or a cycloalkyl group, provided that when k≧2, at least two R 3 s may be bonded to each other to thereby form a ring, X represents an alkylene group, an oxygen atom or a sulfur atom, Y is any of groups of formula (Y2) below, in which R 4 represents an alkyl group, and each of R 5 and R 6 independently represents an alkyl group or a cycloalkyl group, provided that R 5 and R 6 may be bonded to each other to thereby form a ring, k is an integer of 0 to 5, and m is an integer of 1 to 5, satisfying the relationship m+k≦6.