The present invention provides a sulfonium salt photoinitiator, a preparation method therefor, a photocurable composition comprising sulfonium salt photoinitiator, and use thereof. The sulfonium salt photoinitiator has a structure represented by formula (I). By modifying the structure of an existing sulfonium salt photoinitiator, a sulfonium salt photoinitiator having a new structure is obtained, which can exhibits a higher photosensitivity and an excellent as well as characteristics of low odor and low toxicity, when being used in a photocurable composition. This is significantly superior to existing similar photoinitiators. ##STR00001##

The present invention provides a sulfonium salt photoinitiator, a preparation method therefor, a photocurable composition comprising sulfonium salt photoinitiator, and use thereof. The sulfonium salt photoinitiator has a structure represented by formula (I). By modifying the structure of an existing sulfonium salt photoinitiator, a sulfonium salt photoinitiator having a new structure is obtained, which can exhibits a higher photosensitivity and an excellent as well as characteristics of low odor and low toxicity, when being used in a photocurable composition. This is significantly superior to existing similar photoinitiators. ##STR00001##

A radiation-sensitive resin composition contains: a polymer that includes a structural unit including an acid-labile group; and a radiation-sensitive acid generating agent. The radiation-sensitive acid generating agent includes a sulfonate anion and a radiation-sensitive cation. The sulfonate anion includes two or more rings, and an iodine atom and a monovalent group having 0 to 10 carbon atoms which includes at least one of an oxygen atom and a nitrogen atom bond to at least one of the two or more rings. The ring is preferably an aromatic ring. The radiation-sensitive acid generating agent is preferably a compound represented by formula (1). In the formula (1), A.sup.1 represents a group obtained from a compound which includes a ring having 3 to 20 ring atoms by removing (p+q+r+1) hydrogen atoms on the ring. ##STR00001##

A photoresist composition, including an acid-sensitive polymer and photoacid generator compound having Formula (I):

##STR00001##

wherein, EWG, Y, R, and M.sup.+ are the same as described in the specification.

A photoresist composition, including an acid-sensitive polymer and photoacid generator compound having Formula (I):

##STR00001##

wherein, EWG, Y, R, and M.sup.+ are the same as described in the specification.

A chemically amplified positive-type photosensitive resin composition with which a resist pattern having a rectangular cross-sectional shape is easily formed, which has satisfactory sensitivity, and which can suppress decomposition of the acid generating agent; a photosensitive dry film having a photosensitive layer including the photosensitive resin composition; a method for producing the photosensitive dry film; a method for producing a patterned resist film using the positive-type photosensitive resin composition; a method for producing a substrate provided with a template using the positive-type photosensitive resin composition; and a method for producing a plated article using the positive-type photosensitive resin composition. The photosensitive resin composition includes an acid generating agent to generate an acid by irradiation with an active ray or radiation, a resin having alkali solubility that increases under action of an acid, and an acid diffusion suppressing agent, wherein the acid generating agent includes a non-ionic acid generating agent that generates sulfonic acid upon the irradiation, and the acid diffusion suppressing agent includes a compound having a specific structure that is decomposed by the irradiation.

Provided are: a new sulfonium salt highly photosensitive to active energy ray, in particular, i-line or h-line; and a new photoacid generator which is highly photosensitive to i-line or h-line, and comprises a sulfonium salt that is highly soluble in a solvent and a cationically polymerizable compound such as an epoxy compound, and has excellent storage stability in the formulation. The present invention pertains to a sulfonium salt represented by general formula (1), and a photoacid generator comprising said sulfonium salt.

##STR00001##

Provided are: a new sulfonium salt highly photosensitive to active energy ray, in particular, i-line or h-line; and a new photoacid generator which is highly photosensitive to i-line or h-line, and comprises a sulfonium salt that is highly soluble in a solvent and a cationically polymerizable compound such as an epoxy compound, and has excellent storage stability in the formulation. The present invention pertains to a sulfonium salt represented by general formula (1), and a photoacid generator comprising said sulfonium salt.

##STR00001##

Disclosed are a salt represented by formula (I), an acid generator, and a resist composition including the same:

##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, etc.; L.sup.10 represents an alkanediyl group; R.sup.10 represents an acid-labile group; 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 haloalkyl group or a hydrocarbon group; A.sup.1, A.sup.2 and A.sup.3 each represent a hydrocarbon group which may have a substituent, and —CH.sub.2— included in the hydrocarbon group may be replaced by —O—, —CO—, —S— or —SO.sub.2—; m1 represents an integer of 1 to 5, m2, m3, m8 and m9 represent an integer of 0 to 5, m4 to m7 represent an integer of 0 to 4, 1≤m1+m7≤5, 0≤m2+m8≤5, 0≤m3+m9≤5; and AI.sup.− represents an organic anion.

Disclosed are a salt represented by formula (I), an acid generator, and a resist composition including the same:

##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, etc.; L.sup.10 represents an alkanediyl group; R.sup.10 represents an acid-labile group; 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 haloalkyl group or a hydrocarbon group; A.sup.1, A.sup.2 and A.sup.3 each represent a hydrocarbon group which may have a substituent, and —CH.sub.2— included in the hydrocarbon group may be replaced by —O—, —CO—, —S— or —SO.sub.2—; m1 represents an integer of 1 to 5, m2, m3, m8 and m9 represent an integer of 0 to 5, m4 to m7 represent an integer of 0 to 4, 1≤m1+m7≤5, 0≤m2+m8≤5, 0≤m3+m9≤5; and AI.sup.− represents an organic anion.