A salt represented by formula (I), an acid generator and a resist composition:

##STR00001##

wherein R.sup.1, R.sup.2 and R.sup.3 each represent a hydroxy group, —O—R.sup.10, —O—CO—O—R.sup.10, —O-L.sup.1-CO—O—R.sup.10; R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 each represent a halogen atom, a hydroxy group, etc.; L.sup.1 represents an alkanediyl group; R.sup.10 represents an acid-labile group; X.sup.1, X.sup.2 and X.sup.3 each represent an oxygen atom or a sulfur atom; m1 and m7 represent an integer of 0 to 5, m2 to m6 and m8, m9 represent an integer of 0 to 4, in which 0≤m1+m7≤5, 0≤m2+m8≤4, 0≤m3+m9≤4, and at least one of m1, m2 and m3 represents an integer of 1 or more; X.sup.4 represents a single bond, —CH.sub.2—, —O—, —S—, etc.; and AI.sup.− represents an organic anion.

A salt represented by formula (I), an acid generator and a resist composition:

##STR00001##

wherein R.sup.1, R.sup.2 and R.sup.3 each represent a hydroxy group, —O—R.sup.10, —O—CO—O—R.sup.10, —O-L.sup.1-CO—O—R.sup.10; R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 each represent a halogen atom, a hydroxy group, etc.; L.sup.1 represents an alkanediyl group; R.sup.10 represents an acid-labile group; X.sup.1, X.sup.2 and X.sup.3 each represent an oxygen atom or a sulfur atom; m1 and m7 represent an integer of 0 to 5, m2 to m6 and m8, m9 represent an integer of 0 to 4, in which 0≤m1+m7≤5, 0≤m2+m8≤4, 0≤m3+m9≤4, and at least one of m1, m2 and m3 represents an integer of 1 or more; X.sup.4 represents a single bond, —CH.sub.2—, —O—, —S—, etc.; and AI.sup.− represents an organic anion.

A resist composition comprising a base polymer and an onium salt of N-carbonylsulfonamide having iodized benzene ring offers a high sensitivity, minimal LWR and improved CDU, independent of whether it is of positive or negative tone.

A radiation-sensitive resin composition includes: a first polymer including a structural unit including an acid-labile group; a second polymer including a structural unit represented by formula (1); and a radiation-sensitive acid generator. In the formula (1), A represents an oxygen atom or a sulfur atom; a sum of m and n is 2 or 3, wherein m is 1 or 2, and n is 1 or 2; X represents a single bond or a divalent organic group having 1 to 20 carbon atoms; and R.sup.1 represents a monovalent organic group including a fluorine atom.

##STR00001##

A radiation-sensitive resin composition includes: a first polymer including a structural unit including an acid-labile group; a second polymer including a structural unit represented by formula (1); and a radiation-sensitive acid generator. In the formula (1), A represents an oxygen atom or a sulfur atom; a sum of m and n is 2 or 3, wherein m is 1 or 2, and n is 1 or 2; X represents a single bond or a divalent organic group having 1 to 20 carbon atoms; and R.sup.1 represents a monovalent organic group including a fluorine atom.

##STR00001##

A positive resist composition is provided comprising (A) an acid generator in the form of a sulfonium salt consisting of a fluorine-containing sulfonate anion and a fluorine-containing sulfonium cation, (B) a quencher in the form of a sulfonium salt containing at least two fluorine atoms in its cation or containing at least 5 fluorine atoms in its anion and cation, and (C) a base polymer comprising repeat units (a1) having a carboxy group whose hydrogen is substituted by an acid labile group and/or repeat units (a2) having a phenolic hydroxy group whose hydrogen is substituted by an acid labile group. The resist composition exhibits a high sensitivity, high resolution and improved LWR or CDU.

A positive resist composition is provided comprising (A) an acid generator in the form of a sulfonium salt consisting of a fluorine-containing sulfonate anion and a fluorine-containing sulfonium cation, (B) a quencher in the form of a sulfonium salt containing at least two fluorine atoms in its cation or containing at least 5 fluorine atoms in its anion and cation, and (C) a base polymer comprising repeat units (a1) having a carboxy group whose hydrogen is substituted by an acid labile group and/or repeat units (a2) having a phenolic hydroxy group whose hydrogen is substituted by an acid labile group. The resist composition exhibits a high sensitivity, high resolution and improved LWR or CDU.

Disclosed are a salt represented by formula (1), 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 (1), 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.

Electrochemical cells and photoelectrochemical cells for the reduction of furfurals are provided. Also provided are methods of using the cells to carry out the reduction reactions. Using the cells and methods, furfurals can be converted into furan alcohols or linear ketones.