Abstract: The present invention provides a photoresist composition comprising a salt represented by the formula (I): wherein R1 and R2 independently each represent a fluorine atom or a C1-C6 perfluoroalkyl group, X1 represents a C1-C17 divalent saturated hydrocarbon group, etc., s1 represents 1 or 2, and t1 represents 0 or 1, with proviso that sum of s1 and t1 is 1 or 2, R3 represents a C1-C12 saturated hydrocarbon group, etc., u1 represents an integer of 0 to 8, and (Z1)+ represents an organic cation, a salt represented by the formula (II-0): wherein R4 represents a C1-C24 hydrocarbon group etc., X2 represents a C1-C6 alkanediyl group etc., and (Z2)+ represents an organic cation, and a resin being insoluble or poorly soluble in an aqueous alkali solution but becoming soluble in an aqueous alkali solution by the action of an acid.

Abstract: The present invention provides a photoresist composition containing: a resin which contains a structural unit derived from a compound having an acid-labile group and which is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid; an acid generator and a compound represented by the formula (I): wherein R1, X1, R2, u1, s1, t1 are each defined in the specification, with the proviso that sum of s1 and t1 is 1 or 2.

Abstract: A resist composition having a resin having a structural unit represented by the formula (I), a resin being insoluble or poorly soluble in alkali aqueous solution, but becoming soluble in an alkali aqueous solution by the action of an acid and not including the structural unit represented by the formula (I), and an acid generator, wherein R1, A1, R2, Rb1, Rb2, Lb1, ring Wb1, Rb3, Rb4, and Z1+ are defined in the specification.

Abstract: The present invention provides a salt represented by the formula (I): wherein Q1 and Q2 independently each represent a fluorine atom or a C1-C6 perfluoroalkyl group, L1 represents a C1-C17 divalent saturated hydrocarbon group in which one or more —CH2— can be replaced by —O— or —CO—, L2 represents a single bond or a C1-C6 alkanediyl group in which one or more —CH2— can be replaced by —O— or —CO—, Y represents a C3-C18 alicyclic hydrocarbon group which can have one or more substituents, and one or more —CH2— in the alicyclic hydrocarbon group can be replaced by —O—, —CO— or —SO2—, and Z+ represents an organic counter ion.

Abstract: A salt having a divalent group represented by the formula (aa): wherein Xa and Xb independently each represent —O— or —S—, Ra, Rb, Rc and Rd independently each represent a hydrogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group, and m represents 1 or 2.

Abstract: A resist composition having a resin having a structural unit represented by the formula (I), a resin being insoluble or poorly soluble in alkali aqueous solution, but becoming soluble in an alkali aqueous solution by the action of an acid and not including the structural unit represented by the formula (I), an acid generator, and a compound represented by the formula (II), wherein R1, A1, A13, A14, X12, R23, R24, R25, R26, X21 and X22 are defined in the specification.

Abstract: A resist composition having a resin having a structural unit represented by the formula (I), a resin being insoluble or poorly soluble in alkali aqueous solution, but becoming soluble in an alkali aqueous solution by the action of an acid and not including the structural unit represented by the formula (I), and an acid generator, wherein R1, A1, R2, Rb1, Rb2, Lb1, ring Wb1, Rb3, Rb4, and Z1+ are defined in the specification.

Abstract: A resist composition having a resin having a structural unit represented by the formula (I), a resin being insoluble or poorly soluble in alkali aqueous solution, but becoming soluble in an alkali aqueous solution by the action of an acid and not including the structural unit represented by the formula (I), and an acid generator, wherein R1, A1, A13, A14, X12, Rb1, Rb2, Lb1, ring Wb1, Rb3, Rb4, m and Z1+ are defined in the specification.

Abstract: A salt represented by the formula (a1): wherein Q1 and Q2 each independently represent a fluorine atom or a C1-C4 perfluoroalkyl group, X1 represents —CO—O—Xa1— or —CH2—O—Xa2— wherein Xa1 and Xa2 independently each represent a C1-C15 alkylene group and one or more —CH2— in the alkylene group can be replaced by —O— or —CO—, Y1 represents a C3-C36 alicyclic hydrocarbon group or a C6-C24 aromatic hydrocarbon group, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group can have one or more substituents, and one or more —CH2— in the alicyclic hydrocarbon group can be replaced by —O— or —CO—, and Z+ represents an organic cation.

Abstract: The present invention provides a photoresist composition comprising a salt represented by the formula (I): wherein R1 and R2 independently each represent a fluorine atom or a C1-C6 perfluoroalkyl group, X1 represents a C1-C17 divalent saturated hydrocarbon group, etc., s1 represents 1 or 2, and t1 represents 0 or 1, with proviso that sum of s1 and t1 is 1 or 2, R3 represents a C1-C12 saturated hydrocarbon group, etc., u1 represents an integer of 0 to 8, and (z1)+ represents an organic cation, a salt represented by the formula (II-0): wherein R4 represents a C1-C24 hydrocarbon group etc., X2 represents a C1-C6 alkanediyl group etc., and (Z2)+ represents an organic cation, and a resin being insoluble or poorly soluble in an aqueous alkali solution but becoming soluble in an aqueous alkali solution by the action of an acid.

Abstract: The present invention provides a photoresist composition containing: a resin which contains a structural unit derived from a compound having an acid-labile group and which is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid; an acid generator and a compound represented by the formula (I): wherein R1, X1, R2, u1, s1, t1 are each defined in the specification, with the proviso that sum of s1 and t1 is 1 or 2.

Abstract: The present invention provides a salt represented by the formula (I): wherein Q1 and Q2 independently each represent a fluorine atom or a C1-C6 perfluoroalkyl group, L1 represents a C1-C17 divalent saturated hydrocarbon group in which one or more —CH2— can be replaced by —O— or —CO—, L2 represents a single bond or a C1-C6 alkanediyl group in which one or more —CH2— can be replaced by —O— or —CO—, Y represents a C3-C18 alicyclic hydrocarbon group which can have one or more substituents, and one or more —CH2— in the alicyclic hydrocarbon group can be replaced by —O—, —CO— or —SO2—, and Z+ represents an organic counter ion.

Abstract: A resist composition contains (A1) a resin having a structural unit represented by the formula (I), (A2) a resin being insoluble or poorly soluble in alkali aqueous solution, but becoming soluble in an alkali aqueous solution by the action of an acid, (B) an acid generator, and (D) at least one compound selected from the group consisting of a compound represented by the formula (II1) and a compound represented by the formula (II2), wherein R1, A1, R2, R6, X1, X2, R3, R4 and R5 are defined in the specification.

Abstract: The present invention is a salt represented by the formula (I) wherein R1 and R2 independently represent a fluorine atom or a C1 to C6 perfluoroalkyl group; L1 represents a C1 to C17 divalent saturated hydrocarbon group, a —CH2— contained in the saturated hydrocarbon group may be replaced by —O— or —CO—; ring W1 represents a C2 to C36 heterocycle; R3 represents a hydrogen atom or a C1 to C12 hydrocarbon group, a —CH2— contained in the hydrocarbon group may be replaced by —O— or —CO—; R4 in each occurrence independently represent a C1 to C6 hydrocarbon group, a —CH2— contained in the hydrocarbon group may be replaced by —O— or —CO—; m represents an integer of 0 to 6; and Z+ represents an organic cation.

Abstract: The present invention provides a salt represented by the formula (I): wherein R1 and R2 each independently represent a fluorine atom or a C1-C6 perfluoroalkyl group, X1 represents a C1-C17 divalent saturated hydrocarbon group in which one or more —CH2— can be replaced by —O— or —CO— and which can have one or more fluorine atoms, R3 represents a hydrogen atom or a methyl group, and Z1+ represents an organic counter cation, and a photoresist composition containing the same.

Abstract: A salt represented by the formula (I): wherein R1 and R2 each independently represent a fluorine atom or a C1-C6 perfluoroalkyl group, X1 represents a C1-C17 divalent saturated hydrocarbon group which can have one or more fluorine atoms and in which one or more —CH2— can be replaced by —O— or —CO—, R3 represents a group having a cyclic ether structure, and Z1+ represents an organic cation.

Abstract: The present invention provides a photoresist composition comprising an acid generator and a resin comprising a structural unit derived from a monomer represented by the formula (I): wherein R1 represents a hydrogen atom etc., R2 represents a hydrogen atom or a C1-C4 alkyl group, A1 represents a single bond etc., and B1 represents a group represented by the formula (1a): wherein R3, R4 and R5 each independently represents a C1-C16 aliphatic hydrocarbon group and R4 and R5 can be bonded each other to form a C3-C18 ring together with the carbon atom to which R4 and R5 are bonded, a C4-C20 saturated cyclic group having a lactone structure or a C5-C20 saturated cyclic hydrocarbon group having at least one hydroxyl group.

Abstract: A salt having a divalent group represented by the formula (aa): wherein Xa and Xb independently each represent —O— or —S—, Ra, Rb, Rc and Rd independently each represent a hydrogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group, and m represents 1 or 2.

Abstract: A salt represented by the formula (a1): wherein Q1 and Q2 each independently represent a fluorine atom or a C1-C4 perfluoroalkyl group, X1 represents —CO—O—Xa1— or —CH2—O—Xa2— wherein Xa1 and Xa2 independently each represent a C1-C15 alkylene group and one or more —CH2— in the alkylene group can be replaced by —O— or —CO—, Y1 represents a C3-C36 alicyclic hydrocarbon group or a C6-C24 aromatic hydrocarbon group, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group can have one or more substituents, and one or more —CH2— in the alicyclic hydrocarbon group can be replaced by —O— or —CO—, and Z+ represents an organic cation.

Abstract: The present invention provides a chemically amplified positive resist composition comprising (i) a polymer which is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid, (ii) an acid generator, and (iii) a compound of the formula (I). The present invention also provides an ester derivative useful as a component of the chemically amplified positive resist composition, and process for producing the ester derivative.