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

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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).

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A positive resist composition is provided comprising a base polymer end-capped with a salt consisting of an ammonium cation linked to a sulfide group and a fluorinated anion. Because of controlled acid diffusion, a resist film of the composition forms a pattern of good profile with a high resolution and reduced edge roughness or dimensional variation.

A resist composition includes (A1) a resin including a structural unit represented by formula (1) and a structural unit represented by formula (II), and no acid-labile group, (A2) a resin having an acid-labile group, and an acid generator:

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wherein R.sup.1 and R.sup.2 each represent a hydrogen atom, a halogen atom, or an alkyl group which may have a halogen atom, X.sup.1 and X.sup.2 each represent a single bond or *—CO—O—, L.sup.1 represents a single bond or a hydrocarbon group which may have a substituent, and —CH.sub.2— included in the group may be replaced by —O—, —S—, —SO.sub.2— or —CO—, ring W represents a hydrocarbon ring which may have a substituent, mi and mk represent an integer of 1 to 4, and L.sup.2 represents a single bond or a hydrocarbon group which may have a substituent, and —CH.sub.2— included in the group may be replaced by —O—, —S—, —SO.sub.2— or —CO—.

An actinic ray-sensitive or radiation-sensitive resin composition contains a compound that generates an acid upon irradiation with actinic rays or radiation and a resin whose polarity increases by the action of an acid, in which the compound is represented by a specific General Formula (X).

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 resist composition comprising a base polymer and a sulfonium salt of a carboxylic acid having an iodine or bromine-substituted hydrocarbyl group offers a high sensitivity, minimal LWR and improved CDU, independent of whether it is of positive or negative tone.

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).

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Photoresist compositions comprise: an acid-sensitive polymer comprising a repeating unit comprising an ester acetal group, wherein the acid-sensitive polymer is free of tertiary alkyl ester groups and is substantially free of aromatic groups; a material comprising a base-labile group; a photoacid generator compound that is free of fluorine which generates an acid having a pKa of -2 or greater, and wherein the photoresist composition is free of photoacid generators that generate an acid having a pKa of less than -2; and a solvent.. The photoresist compositions and pattern formation methods using the photoresist compositions find particular use in the formation of fine lithographic patterns in the semiconductor manufacturing industry.