Patent ID: 8883394

Claim:
A chemically amplified photoresist composition comprising; a resin (A), and an acid generator (B), wherein the resin (A) contains a copolymer (A1) and an another polymer (A2), the copolymer (A1) is obtained by polymerizing at least: a (meth)acrylic monomer (a1) having a C 5-20 alicyclic hydrocarbon group, which becomes soluble in an aqueous alkali solution by the action of an acid; a (meth)acrylic monomer (a2) having a hydroxyl group-containing adamantyl group; and a (meth)acrylic monomer (a3) having a lactone ring, the copolymer (A1) has a weight-average molecular weight of 2,500 or more and 5,000 or less, a content of the copolymer (A1) is not less than 50 parts by mass with respect to 100 parts by mass of the resin (A) provided that the content of the copolymer (A1) is less than 100 parts by mass with respect to 100 parts by mass of the resin (A), said another polymer (A2) has a weight-average molecular weight of more than 5,000 and 20,000 or less, and the acid generator (B) is a salt represented by formula (B1): wherein Q 1 and Q 2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group, L b1 represents a single bond, an oxygen atom (—O—), a carbonyl group (—CO—), a linear or branched C 1-17 alkanediyl group, or a combination of at least two selected from the group consisting of an oxygen atom, a carbonyl group, and a linear or branched C 1-17 alkanediyl group, Y is an adamantyl group having a substituent or not, or an oxoadamantyl group having a substituent or not, and Z + represents an organic cation.