A salt represented by formula (I), a resin comprising a structural unit derived from the salt represented by formula (I), a resit composition comprising the salt represented by formula (I) or a resin comprising a structural unit derived from the salt represented by formula (I).

##STR00001##

An actinic ray-sensitive or radiation-sensitive resin composition includes an acid-decomposable resin and a specific compound, in which the specific compound has two or more cationic moieties and the same number of anionic moieties as that of the cationic moieties, and at least one of the cationic moieties has a group represented by General Formula (I).

An actinic ray-sensitive or radiation-sensitive resin composition includes an acid-decomposable resin and a specific compound, in which the specific compound has two or more cationic moieties and the same number of anionic moieties as that of the cationic moieties, and at least one of the cationic moieties has a group represented by General Formula (I).

A radiation-sensitive resin composition includes: a polymer including a structural unit including an acid-labile group; and a compound represented by formula (1). R.sup.1, R.sup.2, and R.sup.3 each independently represent a halogen atom, a hydroxy group, a nitro group, or a monovalent organic group having 1 to 20 carbon atoms; X.sup.1, X.sup.2, and X.sup.3 each independently represent a group represented by formula (2); a sum of d, e, and f is no less than 1; R.sup.4 represents a hydrocarbon group having 1 to 20 carbon atoms and R.sup.5 represents a hydrocarbon group having 1 to 20 carbon atoms, or R.sup.4 and R.sup.5 taken together represent a heterocyclic structure having 4 to 20 ring atoms, together with the sulfur atom to which R.sup.4 and R.sup.5 bond; n is 0 or 1; A.sup.− represents a monovalent sulfonic acid anion; and Y represents —COO—, —OCO—, or —N(R.sup.7)CO—.

##STR00001##

Disclosed are a salt represented by formula (I), and an acid generator and a resist composition which include the same: ##STR00001## wherein R1 represents a fluorine atom or a fluorinated alkyl group; R2, R3 and R4 each represent a halogen atom, a fluorinated alkyl group or a hydrocarbon group; m2 and m3 represent an integer of 0 to 4; m4 represents an integer of 0 to 5; Q1 and Q2 each represent a fluorine atom or a perfluoroalkyl group; L1 represents a saturated hydrocarbon group, —CH2- included in the group may be replaced by —O— or —CO—, and a hydrogen atom included in the group may be substituted with a fluorine atom or a hydroxy group; Y1 represents a methyl group which may have a substituent or an alicyclic hydrocarbon group which may have a substituent.

Disclosed are a salt represented by formula (I), and an acid generator and a resist composition which include the same: ##STR00001## wherein R1 represents a fluorine atom or a fluorinated alkyl group; R2, R3 and R4 each represent a halogen atom, a fluorinated alkyl group or a hydrocarbon group; m2 and m3 represent an integer of 0 to 4; m4 represents an integer of 0 to 5; Q1 and Q2 each represent a fluorine atom or a perfluoroalkyl group; L1 represents a saturated hydrocarbon group, —CH2- included in the group may be replaced by —O— or —CO—, and a hydrogen atom included in the group may be substituted with a fluorine atom or a hydroxy group; Y1 represents a methyl group which may have a substituent or an alicyclic hydrocarbon group which may have a substituent.

Provided is an onium salt functioning as a photoacid generator. The photoacid generator can provide a chemically amplifiable photoresist composition when it is combined with a resin component whose solubility in alkali is increased by the action of an acid generated by active energy ray irradiation such as Light or electron beam irradiation. The present invention relates to an onium salt represented by the formula (1), containing an anion structure with a proportion of a facial isomer in a total of the facial isomer and a meridional isomer being 15.0% by weight or lower.

[(R.sup.2).sub.n+1-E].sup.+[(R.sup.1).sub.3(F).sub.3P].sup.−  (1)

Provided is an onium salt functioning as a photoacid generator. The photoacid generator can provide a chemically amplifiable photoresist composition when it is combined with a resin component whose solubility in alkali is increased by the action of an acid generated by active energy ray irradiation such as Light or electron beam irradiation. The present invention relates to an onium salt represented by the formula (1), containing an anion structure with a proportion of a facial isomer in a total of the facial isomer and a meridional isomer being 15.0% by weight or lower.

[(R.sup.2).sub.n+1-E].sup.+[(R.sup.1).sub.3(F).sub.3P].sup.−  (1)

The present invention provides an actinic ray-sensitive or radiation-sensitive resin composition with which a pattern having excellent LWR performance can be obtained, a resist film, a pattern forming method, a method for manufacturing an electronic device, a compound, and a method for producing the compound. The actinic ray-sensitive or radiation-sensitive resin composition of an embodiment of the present invention is an actinic ray-sensitive or radiation-sensitive resin composition including a resin having a repeating unit having a group having a polarity that increases through decomposition by the action of an acid, in which the actinic ray-sensitive or radiation-sensitive resin composition further includes, in addition to the resin, a compound having at least one cation represented by General Formula (1), or the resin further has, in addition to the repeating unit, a repeating unit having the cation represented by General Formula (1).

(R.sup.d1).sub.m—[X.sup.d1].sup.+-(L.sup.d1-Ar.sup.d1—(S—X.sup.d2).sub.p).sub.n   (1)

A salt represented by formula (I), a resin comprising a structural unit derived from the salt represented by formula (I), a resit composition comprising the salt represented by formula (I) or a resin comprising a structural unit derived from the salt represented by formula (I).

##STR00001##