A photoresist composition includes a polymer that includes a structural unit shown by the following formula (1), and a photoacid generator. R
1
in the formula (1) represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, Z represents a group that forms a divalent alicyclic group having 3 to 20 carbon atoms together with a carbon atom bonded to X, X represents an alkanediyl group having 1 to 6 carbon atoms, Y represents a hydrogen atom or —CR
2
R
3
(OR
4
), and R
2
to R
4
independently represent a hydrogen atom or a monovalent hydrocarbon group, provided that R
3
and R
4
optionally bond to each other to form a cyclic ether structure together with a carbon atom bonded to R
3
and an oxygen atom bonded to R
4
.
一种光阻剂组合物包括一个聚合物,该聚合物包括下式(1)所示的结构单元,以及一个光酸发生剂。在式(1)中,R1代表氢原子、
氟原子、甲基基团或三
氟甲基基团,Z代表与与X键合的碳原子一起形成具有3到20个碳原子的二价脂环族基团,X代表具有1到6个碳原子的脂肪二基基团,Y代表氢原子或—CR2R3(OR4),R2到R4独立地代表氢原子或一价烃基团,其中R3和R4可选择地相互键合以与与R3键合的碳原子和与R4键合的氧原子一起形成环状醚结构。