JP2000267281A5 - - Google Patents

Claims (6)

(A) a copolymer A having structural units represented by the following general formulas (I), (II) and (III), (b) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (c) ) A positive photoresist composition comprising a solvent.

In general formulas (I) to (III), R ₁ and R ₂ may be the same or different, each represents a hydrogen atom or a methyl group, and R ₃ represents a tertiary alkyl group that may be substituted.
In general formula (III), R ′ ₁ and R ′ ₂ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, W represents a divalent organic group, R ' ₃ is a chain alkyl group that may have a substituent, a cyclic alkyl group that may have a substituent, an aryl group that may have a substituent, or an aralkyl that may have a substituent Represents a group. R ′ _{3 in} the general formula (III) is an aryl group which may have a substituent having a total carbon number of 11 to 30 or an aralkyl group which may have a substituent of a total carbon number of 12 to 30. The positive photoresist composition according to claim 1, wherein: The positive photoresist composition according to claim 1 or 2, wherein the copolymer A of (a) further contains a structural unit represented by the following general formula (IV).

In the formula, R ₁ is a hydrogen atom or a methyl group. R represents a hydrogen atom, a straight chain having 1 to 4 carbon atoms, a branched alkyl group, a methoxy group, or an acetoxy group. The positive photoresist composition according to claim 1, wherein the copolymer A of (a) further contains a structural unit represented by the following general formula (V).

In the formula, R ₁ is a hydrogen atom or a methyl group.
R _{4 to} R ₈ may be the same or different and each represents a hydrogen atom, a hydroxyl group, a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom. .
m shows the integer of 1-6. The said (b) compound which generate | occur | produces an acid by irradiation of actinic light or a radiation is at least 1 sort (s) of the sulfonium salt shown by the following general formula (VI), The Claim 1 characterized by the above-mentioned. A positive photoresist composition.

In the formula, three R _{9 s} may be the same or different and each represents a hydrogen atom or a branched alkyl group having 3 to 16 carbon atoms. However, at least one is not a hydrogen atom. A resist film is formed with the positive photoresist composition according to claim 1, and the resist film is exposed and developed.
Method.