Photosensitive resin composition

Abstract

To provide a photosensitive resin composition which enables formation of a resin film that is excellent in photolithographic characteristics and chemical resistance, a cured product of the photosensitive resin composition, a method for producing a cured product using the photosensitive resin composition, and a method for producing an optical element using the photosensitive resin composition.SOLUTION: In a photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B) for generating an acid by irradiation with active rays or radiation rays, and a crosslinking agent (C), a polyhydrostyrene resin (A) in which a part of a phenolic hydroxyl group is an acetal type protective group, and a polyfunctional epoxy compound (C1) having two or more epoxy groups are used.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a photosensitive resin composition, a cured product of the photosensitive resin composition, and a method for producing an optical element using the photosensitive resin composition. [Background technology]

[0002] Conventionally, solid-state imaging elements are used in cameras, video cameras, etc. These solid-state imaging elements include CCD (charge-coupled device) image sensors and CMOS (complementary metal-oxide semiconductor) image sensors. The image sensors are provided with minute condensing lenses (hereinafter referred to as microlenses) for the purpose of improving the light collection rate.

[0003] As a method for forming such microlenses, a method called a thermal flow method is widely adopted industrially. In the thermal flow method, first, a photoresist film is formed on the top of a CCD element or the like. The photoresist film is a film made of a photosensitive resin composition or the like. The photoresist film is then exposed to light and developed to form a dot pattern made of resin on the element. The dot pattern is made of a plurality of dots located at the positions where microlenses are to be formed. Each dot constituting the dot pattern has a substantially cylindrical shape or a substantially truncated cone shape. The dot pattern is heated at a temperature equal to or higher than the glass transition point of the resin material constituting the dots, causing the resin material constituting the dots to flow, and the shape of each dot changes to a hemispherical lens shape due to surface tension. In this way, a microlens pattern is formed (see, for example, Patent Document 1).

[0004] Also, an etch-back method is known as one of the methods for producing a microlens for a CCD or CMOS image sensor. In this method, first, a resin layer for a microlens is formed on a color filter. Then, a lens pattern is formed on the resin layer for a microlens using a photosensitive resin composition by a method similar to the thermal flow method described in the above Patent Document 1. The lens pattern thus formed is used as an etching mask to etch back the lower resin layer for a microlens, and the lens pattern shape is transferred to the resin layer for a microlens to produce a microlens. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-15245 A Summary of the Invention [Problem to be solved by the invention]

[0006] Depending on the application of the optical element, microlenses of different sizes, refractive indices, or shapes may be formed in the optical element. In this case, in the above-mentioned thermal flow method or etch-back method, many work steps are required to form a microlens pattern or a mask pattern having a microlens shape, and thus the dots, the microlens pattern, the mask pattern having a microlens shape, etc. are frequently exposed to chemicals such as organic solvents in the manufacturing process of the optical element. In order to form microlenses of different sizes, refractive indexes, or shapes in an optical element, it is necessary to form microlenses or mask patterns of desired sizes, refractive indexes, or shapes at predetermined positions, and for this purpose, the photosensitive resin composition is required to have good photolithography properties. As described above, the photosensitive resin composition used to form the microlenses is required to have excellent photolithography properties and to be capable of forming a resin film having excellent chemical resistance.

[0007] The present invention has been made in consideration of such conventional circumstances, and has an object to provide a photosensitive resin composition capable of forming a resin film having excellent photolithography properties and excellent chemical resistance, a cured product of the photosensitive resin composition, a method for producing the cured product using the photosensitive resin composition, and a method for producing an optical element using the photosensitive resin composition. [Means for solving the problem]

[0008] The present inventors have found that the above problems can be solved by using a polyhydroxystyrene resin (A) in which some of the phenolic hydroxyl groups are protected by acetal-type protecting groups, and a polyfunctional epoxy compound (C1) having two or more epoxy groups in a photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation, and a crosslinking agent (C), and have arrived at the present invention. Specifically, the present invention provides the following.

[0009] A first aspect of the present invention is a photosensitive resin composition comprising a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation, and a crosslinking agent (C), In the polyhydrostyrene resin (A), a part of the phenolic hydroxyl groups is protected by an acetal-type protecting group, The crosslinking agent (C) is a photosensitive resin composition that is a polyfunctional epoxy compound (C1) having two or more epoxy groups.

[0010] A second aspect of the present invention is a cured product of the photosensitive resin composition according to the first aspect.

[0011] A third aspect of the present invention is A method for manufacturing an optical element having a plurality of microlenses including n types of microlenses on a substrate, the method comprising the steps of: n is an integer of 2 or more, The manufacturing method includes forming a resin film on a substrate; forming a mask on the resin film having a shape corresponding to the shapes of the plurality of microlenses; and etching the resin film together with the mask to form a plurality of microlenses to which the shape of the mask is transferred. The mask is as follows: (i) to (iii): (i) applying an m-th photosensitive resin composition onto the resin film to form an m-th coating film; (ii) exposing and developing the m-th coating film to form an m-th dot at a position on the substrate corresponding to a position where the m-th microlens is to be formed; (iii) heating the m-th dot to deform the m-th dot into a shape corresponding to the shape of the m-th microlens; It is formed by repeating the above operation n times, m is an integer between 1 and n, The first to nth photosensitive resin compositions used in forming the mask may be the same or different, At least one of the first to nth photosensitive resin compositions is the photosensitive resin composition according to the first aspect; A production method in which, when a coating film is formed using the photosensitive resin composition according to the first embodiment, the coating film is not heated after exposure and before development. Effect of the Invention

[0012] According to the present invention, it is possible to provide a photosensitive resin composition capable of forming a resin film having excellent photolithography properties and excellent chemical resistance, a cured product of the photosensitive resin composition, and a method for producing an optical element using the above-mentioned photosensitive resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] ≪Photosensitive resin composition≫ The photosensitive resin composition contains a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation, and a crosslinking agent (C). In the polyhydroxystyrene resin (A), some of the phenolic hydroxyl groups are protected with acetal-type protecting groups. The crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups. The photosensitive resin composition having the above-mentioned features has excellent photolithography properties. Furthermore, when the photosensitive resin composition having the above-mentioned features is used, a resin film having excellent chemical resistance is formed.

[0014] <Polyhydroxystyrene resin (A)> The photosensitive resin composition contains a polyhydroxystyrene resin (A). In the polyhydroxystyrene resin (A), some of the phenolic hydroxyl groups are protected with acetal-type protecting groups. The polyhydroxystyrene resin (A) is deprotected well by the action of the acid generated by the photoacid generator (B) upon exposure to light, and its solubility in the developer changes. Therefore, when a patterned resin film is formed by a photolithography method including development using a photosensitive resin composition containing the polyhydroxystyrene resin (A), it is easy to obtain a resin film patterned into a desired shape. As the developer, it is preferable to use an alkaline developer, since it is easy to obtain a resin film patterned into a desired shape.

[0015] Suitable examples of the polyhydroxystyrene resin (A) include resins having a structural unit represented by the following formula (a1) and a structural unit represented by the following formula (a2). Hereinafter, the structural unit represented by formula (a1) will also be referred to as "structural unit (a1)". The structural unit represented by formula (a2) will also be referred to as "structural unit (a2)".

[0016] [ka] (In formula (a1), R a1 R is a hydrogen atom, an alkyl group, a halogen atom, or a halogenated alkyl group. a2 is a hydrogen atom or an alkyl group. p is an integer of 1 or more and 5 or less. q is an integer of 0 or more and 4 or less.

[0017] [ka] (In formula (a2), R a3 R is a hydrogen atom, an alkyl group, a halogen atom, or a halogenated alkyl group. a4 , R a5 , and R a6 are each independently a hydrogen atom or an alkyl group. a7 is an alkyl group or a cycloalkyl group; r is an integer of 1 or more and 5 or less; s and t are each independently an integer of 0 or more and 4 or less.

[0018] In formula (a1) and formula (a2), R a1 , and R a3 is a hydrogen atom, an alkyl group, a halogen atom, or a halogenated alkyl group. R a1 , and R a3 The number of carbon atoms in the alkyl group as R is not particularly limited as long as the desired effect is not impaired. a1 , and R a3 The number of carbon atoms in the alkyl group represented by R is preferably 1 or more and 5 or less. a1 , and R a3 The alkyl group as R may be linear or branched. a1 , and R a3 Specific examples of the alkyl group as include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, and a neopentyl group, etc. From an industrial viewpoint, a methyl group is preferred.

[0019] R a1 , and R a3Specific examples of the halogen atom as the halogen atom or the halogen atom in the halogenated alkyl include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred. As the halogenated alkyl group, a group in which a part or all of the hydrogen atoms in the above-mentioned alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms is preferred. The halogenated alkyl group may be linear or branched. Specific examples of suitable halogenated alkyl groups include fluorinated alkyl groups such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a nonafluorobutyl group.

[0020] R a1 , and R a3 is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0021] R a2 , and R a4 The number of carbon atoms in the alkyl group represented by R is preferably 1 or more and 5 or less. a2 , and R a4 Suitable examples of alkyl groups as R a1 , and R a3 The preferred examples of the alkyl group are the same as those of the alkyl group.

[0022] Each of q, s, and t is independently an integer of 0 to 4. Of these, q, s, and t are preferably 0 or 1, and are particularly preferably 0 from an industrial standpoint.

[0023] In formula (a1), when q is 1, R a2 The substitution position of is on the benzene ring in formula (a1), a1 The carbon atom bonded to the carbon atom bonded to the ring may be in any of the o-position, m-position, and p-position. If q is an integer between 2 and 4, inclusive, R a2 may be bonded to any position on the benzene ring in formula (a1).

[0024] In formula (a2), when t is 1, R a4The substitution position of is on the benzene ring in formula (a2), R a3 The carbon atom bonded to the carbon atom bonded to the ring may be in any of the o-position, m-position, and p-position. If t is an integer between 2 and 4, R a4 may be bonded to any position on the benzene ring in formula (a2).

[0025] In formula (a1), p is an integer of 1 or more and 5 or less, preferably an integer of 1 or more and 3 or less, and more preferably 1. In formula (a2), s is an integer of 0 or more and 4 or less, preferably an integer of 0 or more and 3 or less, and more preferably 0 or 1. When p is 1 or s is 1, the substitution position of the hydroxyl group in formula (a1) and formula (a2) is R a1 , or R a3 The position may be any of the o-position, m-position, or p-position with respect to the position of the carbon atom bonded to the carbon atom bonded to the structural unit represented by formula (a1) or formula (a2), and the p-position is preferred because monomers that give the structural unit represented by formula (a1) or formula (a2) are easily available and low in cost. When p in formula (a1) is an integer of 2 or more and 5 or less, or when s in formula (a2) is an integer of 2 or more and 4 or less, the hydroxyl group may be bonded to any position on the benzene ring in formula (a1) and formula (a2).

[0026] In formula (a2), r is an integer of 1 or more and 5 or less, preferably an integer of 1 or more and 3 or less, and more preferably 1. When r is 1, -C(R a5 )(R a6 ) OR a7 The substitution position of the group represented by a3 The carbon atom bonded to the carbon atom bonded to the ring may be in any of the o-position, m-position, and p-position. In formula (a2), when r is an integer of 2 or more and 5 or less, -C(R a5 )(R a6 ) OR a7The group represented by the following formula (a2) can be bonded to any position on the benzene ring.

[0027] In formula (a2), -C(R a5 )(R a6 ) OR a7 In the acetal protecting group represented by the formula: a5 , and R a6 are each independently a hydrogen atom or an alkyl group. a7 is an alkyl group or a cycloalkyl group. a5 , R a6 , and R a7 At least two of these may be bonded to each other to form a ring.

[0028] R a5 , or R a6 The number of carbon atoms in the alkyl group represented by R is preferably 1 or more and 6 or less. a5 , or R a6 The alkyl group as may be linear or branched. R a7 The number of carbon atoms in the alkyl group as R is preferably 1 or more and 10 or less. a7 The alkyl group as may be linear or branched. R a7 The cycloalkyl group as the radical preferably has 3 or more and 10 or less carbon atoms, for example.

[0029] Ra 5 , R a6 , or R a7 Specific examples of the alkyl group as include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, and a neopentyl group. R a7 Specific examples of the cycloalkyl group as the aryl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentyl group, and a cyclooctyl group.

[0030] In formula (a2), -C(R a5)(R a6 ) OR a7 Specific examples of the acetal-type protecting group represented by the formula (I) include a 1-methoxyethyl group, a 1-ethoxyethyl group, a 1-n-propoxyethyl group, a 1-isopropoxyethyl group, a 1-n-butoxyethyl group, a 1-isobutoxyethyl group, a 1-tert-butoxyethyl group, a 1-cyclohexyloxyethyl group, a 1-methoxypropyl group, a 1-ethoxypropyl group, a 1-methoxy-1-methyl-ethyl group, and a 1-ethoxy-1-methylethyl group.

[0031] The polyhydroxystyrene resin (A) may contain one or more types of structural units (a1). The polyhydroxystyrene resin (A) may contain one or more types of structural units (a2). The sum of the ratio of the structural unit (a1) and the ratio of the structural unit (a2) in the polyhydroxystyrene resin (A) is preferably 50 mol% or more and 100 mol% or less, more preferably 70 mol% or more and 100 mol% or less, still more preferably 80 mol% or more and 100 mol% or less, particularly preferably 90 mol% or more and 100 mol% or less, and most preferably 100 mol% based on the number of moles of all structural units constituting the polyhydroxystyrene resin (A).

[0032] The ratio of the number of moles of the structural unit (a2) to the total number of moles of the structural unit (a1) and the number of moles of the structural unit (a2) is preferably 10 mol% or more and 60 mol% or less, more preferably 20 mol% or more and 40 mol% or less. This ratio is the protection rate of the hydroxyl group derived from the hydroxystyrene. When the protection rate is within the above range, it is easy to obtain a photosensitive resin composition with particularly good patterning properties.

[0033] The proportion of the number of moles of the structural unit (a2) relative to the number of moles of all structural units constituting the polyhydroxystyrene resin (A) is preferably from 10 mol % to 60 mol %, more preferably from 20 mol % to 40 mol %.

[0034] The polyhydroxystyrene resin (A) may contain a structural unit (a3) ​​other than the structural unit (a1) and the structural unit (a2). Other monomers that provide the other structural unit (a3) ​​include (meth)acrylic acid esters, (meth)acrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, maleimides, etc. These compounds can be used alone or in combination of two or more.

[0035] Examples of (meth)acrylic acid esters include linear or branched alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, amyl (meth)acrylate, and tert-octyl (meth)acrylate; chloroethyl (meth)acrylate, 2,2-dimethylhydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, benzyl (meth)acrylate, furfuryl (meth)acrylate; glycidyl (meth)acrylate; and (meth)acrylic acid esters having a group having an alicyclic skeleton. In the (meth)acrylic acid ester having a group having an alicyclic skeleton, the alicyclic group constituting the alicyclic skeleton may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic group include a norbornyl group, an isobornyl group, a tricyclononyl group, a tricyclodecyl group, and a tetracyclododecyl group.

[0036] Examples of (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, N-aryl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, N,N-aryl(meth)acrylamide, N-methyl-N-phenyl(meth)acrylamide, and N-hydroxyethyl-N-methyl(meth)acrylamide.

[0037] Examples of allyl compounds include allyl esters such as allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, and allyl lactate; allyloxyethanol; and the like.

[0038] Examples of vinyl ethers include aliphatic vinyl ethers such as hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, and tetrahydrofurfuryl vinyl ether; and vinyl aryl ethers such as vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, and vinyl anthranyl ether.

[0039] Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valerate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl phenylacetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, and vinyl naphthoate.

[0040] Examples of styrenes include styrene; alkyl styrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, and acetoxymethylstyrene; alkoxy styrenes such as methoxystyrene, 4-methoxy-3-methylstyrene, and dimethoxystyrene; and halostyrenes such as chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, and 4-fluoro-3-trifluoromethylstyrene.

[0041] Examples of maleimides include maleimides N-substituted with an alkyl group having 1 to 10 carbon atoms, such as N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, Nn-pentylmaleimide, and Nn-hexylmaleimide; maleimides N-substituted with an alicyclic group having 3 to 20 carbon atoms, such as N-cyclopentylmaleimide, N-cyclohexylmaleimide, and N-cycloheptylmaleimide; N-arylmaleimides N-substituted with an aryl group having 6 to 20 carbon atoms, such as N-phenylmaleimide, N-α-naphthylmaleimide, and N-β-naphthylmaleimide; and N-aralkylmaleimides N-substituted with an aralkyl group having 7 to 20 carbon atoms, such as N-benzylmaleimide and N-phenethylmaleimide.

[0042] The weight average molecular weight (Mw) of the polyhydroxystyrene resin (A) is preferably from 5000 to 30000. In this specification, the weight average molecular weight is a polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC).

[0043] <Photoacid generator (B)> The photosensitive resin composition contains a photoacid generator (B) that generates an acid upon irradiation with actinic rays or radiation. The photoacid generator (B) generates an acid upon exposure to light, which deprotects the polyhydroxystyrene resin (A) and changes its solubility in a developer, making the photosensitive resin composition suitable for patterning by photolithography.

[0044] The photoacid generator (B) is not particularly limited, and any photoacid generator that has been incorporated into a photosensitive resin composition can be used without particular limitation. As the photoacid generator (B), a photoacid generator (Ba) that generates an acid in response to actinic rays or radiation having a wavelength of 200 nm or more and 300 nm or less is preferred. Examples of the photoacid generator (B) include onium salt-type photoacid generators such as iodonium salts and sulfonium salts; oxime sulfonate-type photoacid generators; diazomethane-type photoacid generators; nitrobenzylsulfonate-type photoacid generators; iminosulfonate-type photoacid generators; and disulfone-type photoacid generators. Among these, diazomethane-type photoacid generators and onium salt-type photoacid generators are preferred because they are easy to use to obtain a photosensitive resin composition with excellent photolithography properties. Hereinafter, the diazomethane-type photoacid generator is also referred to as diazomethane-type photoacid generator (B1). The onium salt-type photoacid generator is also referred to as onium salt-type photoacid generator (B2). The diazomethane-type photoacid generator (B1) and the onium salt-type photoacid generator (B2) will be described below.

[0045] [Diazomethane-type photoacid generator (B1)] The diazomethane-type photoacid generator (B1) will be described below. Examples of the diazomethane type photoacid generator (B1) include bissulfonyldiazomethane compounds such as bis(alkylsulfonyl)diazomethane, bis(cycloalkylsulfonyl)diazomethane, and bis(arylsulfonyl)diazomethane.

[0046] Specific examples of the bissulfonyldiazomethane compound include bis(isopropylsulfonyl)diazomethane, bis(tert-butylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, and bis(2,4-dimethylphenylsulfonyl)diazomethane.

[0047] Poly(bissulfonyl)diazomethane can also be used as the diazomethane type photoacid generator (B2). Examples of poly(bissulfonyl)diazomethane include 1,3-bis(phenylsulfonyldiazomethylsulfonyl)propane, 1,4-bis(phenylsulfonyldiazomethylsulfonyl)butane, 1,6-bis(phenylsulfonyldiazomethylsulfonyl)hexane, 1,10-bis(phenylsulfonyldiazomethylsulfonyl)decane, 1,2-bis(cyclohexylsulfonyldiazomethylsulfonyl)ethane, 1,3-bis(cyclohexylsulfonyldiazomethylsulfonyl)propane, 1,6-bis(cyclohexylsulfonyldiazomethylsulfonyl)hexane, and 1,10-bis(cyclohexylsulfonyldiazomethylsulfonyl)decane.

[0048] [Onium salt type photoacid generator (B2)] Suitable examples of the onium salt-type photoacid generator (B2) include a compound represented by the following formula (b-1) or a compound represented by formula (b-2). Hereinafter, the compound represented by formula (b-1) is also referred to as "component (b-1)". The compound represented by formula (b-2) is also referred to as "component (b-2)".

[0049] [ka] (In formula (b-1) and formula (b-2), R 101 and R 104 ~R 105 R each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.104 and R 105 may be bonded to each other to form a ring. 102 is a fluorine atom or a fluorine-containing alkyl group having 1 to 5 carbon atoms. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 are each independently a single bond or an oxygen atom. m is an integer of 1 or more. M' m+ is an onium cation with a valence of m.

[0050] (anion part) The anion moiety that constitutes component (b-1) will be described below. In formula (b-1), R 101 represents an optionally substituted cyclic group, an optionally substituted alkyl group, or an optionally substituted alkenyl group.

[0051] R 101 When the cyclic group may have a substituent, the cyclic group is preferably a cyclic hydrocarbon group. The cyclic hydrocarbon group may be an aromatic hydrocarbon group or an alicyclic hydrocarbon group. The alicyclic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0052] R 101 The number of carbon atoms in the aromatic hydrocarbon group as is preferably 6 or more and 30 or less, more preferably 6 or more and 20 or less, even more preferably 6 or more and 15 or less, and particularly preferably 6 or more and 10 or less. However, when the aromatic hydrocarbon group has a substituent, the above number of carbon atoms does not include the number of carbon atoms of the substituent.

[0053] R 101 Specific examples of the aromatic hydrocarbon ring contained in the aromatic hydrocarbon group as the aromatic ring include a benzene ring, a fluorene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a biphenyl ring.

[0054] R 101 The cyclic group as may contain an aromatic heterocycle in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0055] R 101 Specific examples of the aromatic hydrocarbon group as the alkyl group include a phenyl group, a naphthalene-1-yl group, a naphthalene-2-yl group, a 4-phenylphenyl group, a 3-phenylphenyl group, and a 2-phenylphenyl group.

[0056] R 101 The alicyclic hydrocarbon group as the substituent includes an aliphatic hydrocarbon group containing a ring in the structure. Examples of the aliphatic hydrocarbon group that contains a ring in its structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 or more and 20 or less, and more preferably has 3 or more and 12 or less, carbon atoms.

[0057] The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The number of carbon atoms in the monocycloalkane is preferably 3 or more and 6 or less. Specific examples of the monocycloalkane include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane. The number of carbon atoms in the polycycloalkane is preferably 7 to 30. Specific examples of the polycycloalkane include polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a ring group having a steroid skeleton.

[0058] R 101 As the alicyclic hydrocarbon group as described above, a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane is preferable, a group in which one hydrogen atom has been removed from a polycycloalkane is more preferable, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

[0059] The number of carbon atoms of the linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. The linear aliphatic hydrocarbon group is preferably a linear alkylene group. Specific examples of suitable linear alkylene groups include a methylene group, an ethane-1,2-diyl group (ethylene group), a propane-1,3-diyl group (trimethylene group), a butane-1,4-diyl group (tetramethylene group), and a pentane-1,5-diyl group (pentamethylene group).

[0060] The number of carbon atoms in the branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group is preferably 2 or more and 10 or less, more preferably 3 or more and 6 or less, even more preferably 3 or 4, and most preferably 3. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3)-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 -, etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 -, etc. alkyl ethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc.; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0061] R 101 The cyclic group as the cyclic group is a lactone-containing cyclic group, -SO 2 -containing cyclic groups, and other heterocyclic groups.

[0062] "-SO 2 "-containing cyclic group" means a group having a -SO 2 is a cyclic group containing a ring containing a - bond. 2The -containing cyclic group may be a monocyclic group or a polycyclic group. 2 -containing cyclic group is -SO 2 When the ring is composed of only -containing rings, the -SO 2 The -containing cyclic group is a monocyclic group. 2 -containing cyclic group is 2 or more -SO 2 - ring or -SO 2 - With the ring, -SO 2 When the ring has a structure other than the -SO 2 The -containing cyclic group is a polycyclic group. -SO 2 The -containing cyclic group particularly includes an -O-SO 2 Cyclic groups containing a - linkage are preferred. Such cyclic groups contain a sultone ring. -SO 2 More specific examples of the --containing cyclic group include groups represented by the following formulas (b-r2-1) to (b-r2-4).

[0063] [ka] (In formulas (b-r2-1)~(b-r2-4), R b21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 -containing cyclic group; B″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom, an alkylene group having 1 to 5 carbon atoms which may contain a sulfur atom, an oxygen atom, or a sulfur atom; and n′ is 0, 1, or 2.

[0064] In formulas (b-r2-1)~(b-r2-4), R b21The alkyl group as the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group may be linear or branched. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, and an n-hexyl group. Among these, a methyl group and an ethyl group are preferred, and a methyl group is particularly preferred.

[0065] R b21 The alkoxy group as is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group may be linear or branched. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, an n-pentyloxy group, an isopentyloxy group, a neopentyloxy group, and an n-hexyloxy group. Among these, a methoxy group and an ethoxy group are preferred, and a methoxy group is particularly preferred.

[0066] R b21 Examples of the halogen atom as the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred.

[0067] R b21 As the halogenated alkyl group, R b21 As the halogenated alkyl group, a part or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0068] R b21 In -COOR" and -OC(=O)R" as the above, R" is a hydrogen atom, an alkyl group, an alicyclic hydrocarbon group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2The alicyclic hydrocarbon group represented by R″ may be substituted with a fluorine atom or a fluorinated alkyl group.

[0069] In formulae (b-r2-1) to (b-r2-4), the alkylene group having 1 to 5 carbon atoms represented by B" may be linear or branched. Specific examples of the alkylene group include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between the carbon atoms of the alkylene group, such as O-CH 2 -, -CH 2 -O-CH 2 -,-S-CH 2 -, -CH 2 -S-CH 2 B″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group. Specific examples of groups represented by formulae (b-r2-1) to (b-r2-4) are shown below, in which "Ac" represents an acetyl group.

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] In formula (b-1), R 101 Examples of the substituent that the cyclic group as may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

[0074] The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropyloxy group, an n-butyloxy group, or a tert-butyloxy group, and most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom is preferred. The halogenated alkyl group as the substituent is preferably a halogenated alkyl group having 1 to 5 carbon atoms, more preferably a halogenated methyl group, a halogenated ethyl group, a halogenated propyl group, a halogenated n-butyl group, or a halogenated tert-butyl group. The halogenated alkyl group may be a group in which some of the hydrogen atoms in the alkyl group have been substituted with halogen atoms, or may be a group in which all of the hydrogen atoms in the alkyl group have been substituted with halogen atoms. The carbonyl group as a substituent is a methylene group (-CH 2 -) is a group that substitutes

[0075] R 101 The chain alkyl group as may be linear or branched. The linear alkyl group preferably has 1 or more and 20 or less carbon atoms, more preferably has 1 or more and 15 or less carbon atoms, and most preferably has 1 or more and 10 or less carbon atoms. Specific preferred examples of the straight-chain alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, and an n-icosyl group.

[0076] The number of carbon atoms in the branched alkyl group is preferably from 3 to 20, more preferably from 3 to 15, and most preferably from 3 to 10. Specific examples of suitable branched alkyl groups include a 1-methylethyl group (isopropyl group), a 1-methylpropyl group (sec-butyl group), a 2-methylpropyl group (isobutyl group), a 1-methylbutyl group (sec-pentyl group), a 2-methylbutyl group, a 3-methylbutyl group (isobutyl group), a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0077] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group as may be linear or branched. The number of carbon atoms in the chain alkenyl group is preferably 2 to 10, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Suitable specific examples of the linear alkenyl group include a vinyl group, a 1-propenyl group, a 2-propenyl group (allyl group), and a butenyl group. Suitable specific examples of the branched alkenyl group include a 1-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Among the above alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0078] R 101 Examples of the substituent that the chain alkyl group or the chain alkenyl group may have include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R 101 Examples of the cyclic groups include the cyclic groups represented by the formula (I).

[0079] R 101is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, it is preferably a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group, or -SO 2 -containing cyclic groups and the like are preferred.

[0080] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When Y is a divalent linking group containing an oxygen atom, 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of the divalent linking group containing an oxygen atom include an oxygen atom (-O-), -C(=O)-, -OC(=O)-, -C(=O)-NH-, a carbonyl group, -OC(=O)-O-, and other oxygen atom-containing linking groups; combinations of such oxygen atom-containing linking groups with alkylene groups, and the like. 2 Such a divalent linking group containing an oxygen atom may be, for example, the linking groups represented by the following formulae (by-1) to (by-7).

[0081] [ka] (In formulas (by-1) to (by-5), V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0082] V' 102 The divalent saturated hydrocarbon group as V' may be a chain saturated hydrocarbon group, a cyclic saturated hydrocarbon group, or a combination of a chain saturated hydrocarbon group and a cyclic saturated hydrocarbon group. 102The divalent saturated hydrocarbon group as is preferably an alkylene group. The alkylene group preferably has 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms.

[0083] V' 101 and V' 102 The alkylene group as may be linear or branched, and is preferably linear. V' 101 and V' 102 Specific examples of the alkylene group as the alkylene group include a methylene group; 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )- and -C(CH 2 CH 3 ) 2 - and other alkylmethylene groups; ethylene groups (-CH 2 CH 2 -);-CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 - and -CH(CH 2 CH 3 )CH 2 - and other alkylethylene groups; trimethylene groups (-CH 2 CH 2 CH 2 -);-CH(CH 3 )CH 2 CH 2 - and -CH 2 CH(CH 3 )CH 2 - and other alkyl trimethylene groups; tetramethylene groups (-CH 2 CH 2CH 2 CH 2 -);-CH(CH 3 )CH 2 CH 2 CH 2 - and -CH 2 CH(CH 3 )CH 2 CH 2 - and other alkyl tetramethylene groups; pentamethylene groups (-CH 2 CH 2 CH 2 CH 2 CH 2 -) etc.

[0084] Also, V' 101 , or V' 102 In the alkylene group as represented by the formula (I), some of the methylene groups may be substituted with a divalent aliphatic cyclic group having from 5 to 10 carbon atoms. The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The number of carbon atoms in the monocycloalkane is preferably 3 or more and 6 or less. Examples of the group in which two hydrogen atoms have been removed from a monocycloalkane include a cyclopentylene group and a cyclohexylene group. Of these, the cyclohexylene group is more preferred. The aliphatic hydrocarbon group, which is a polycyclic group, is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane. The number of carbon atoms in the polycycloalkane is preferably 7 or more and 12 or less. Examples of the group in which two hydrogen atoms have been removed from a polycycloalkane include an adamantanediyl group, a norbornanediyl group, an isobornanediyl group, a tricyclodecanediyl group, and a tetracyclododecanediyl group. Among these, an adamantane-1,5-diyl group and an adamantane-2,6-diyl group are more preferred.

[0085] The aliphatic cyclic group may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-RP1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN and -R P2 -COOH, etc. R P1 R is an alkyl group having 1 to 10 carbon atoms, a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. R P1 and R P2 may be a group in which some or all of the hydrogen atoms in the above-mentioned chain saturated hydrocarbon group, cyclic saturated hydrocarbon group, and aromatic hydrocarbon group have been substituted with fluorine atoms. The above cyclic hydrocarbon group may have one or more of one type of the above substituents, or may have one or more of each of two or more types of the above substituents.

[0086] Examples of the monovalent alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.0 ... 2,6 ]decanyl group, tricyclo[3.3.1.1 3,7 ]decanyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 ]A dodecanyl group, an adamantyl group, or other polycyclic saturated hydrocarbon group is exemplified. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include a phenyl group, a biphenylyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group.

[0087] Y 101 As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and the linking groups represented by the above formulas (by-1) to (by-5) are more preferable.

[0088] In formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The number of carbon atoms in the alkylene group and the fluorinated alkylene group represented by V is preferably 1 or more and 4 or less. 101 As the fluorinated alkylene group, V 101 In particular, the alkylene group represented by the formula (I) is substituted with fluorine atoms in part or in whole. 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0089] In formula (b-1), R 102 R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 As the group, a fluorine atom and a perfluoroalkyl group having 1 to 5 carbon atoms are preferable, and a fluorine atom is more preferable.

[0090] Y 101 When Y is a single bond, specific examples of the anion moiety represented by formula (b-1) include fluorinated alkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion. 101 When is a divalent linking group containing an oxygen atom, specific examples of the anion moiety represented by formula (b-1) include anions represented by the following formulas (ba-1) to (ba-3).

[0091] [ka] (In formulas (ba-1) to (ba-3), R 101 R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group, or an alkyl group which may have a substituent. 102 represents an aliphatic cyclic group which may have a substituent, a lactone-containing cyclic group, or -SO represented by any one of formulas (b-r2-1) to (b-r2-4). 2 -containing cyclic group. 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or an alkenyl group which may have a substituent. 101 R is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0092] R” 101 , R.” 102 , and R.” 103 The optionally substituted aliphatic cyclic group represented by R 101 As the substituent, R in formula (b-1) is preferably a group exemplified as the alicyclic hydrocarbon group. 101 Examples of the substituents which may be substituted on the alicyclic hydrocarbon group as mentioned above include the same groups as those which may be substituted on the alicyclic hydrocarbon group as mentioned above.

[0093] R” 103 The aromatic cyclic group which may have a substituent as R 101 The substituents are preferably the groups exemplified as the aromatic hydrocarbon group as the cyclic hydrocarbon group. 101 Examples of the substituents which may be substituted on the aromatic hydrocarbon group as mentioned above include the same groups as those which may be substituted on the aromatic hydrocarbon group as mentioned above.

[0094] R” 101 The chain alkyl group which may have a substituent as R in formula (b-1) is 101Preferably, it is a group exemplified as the chain alkyl group as above. R” 103 The chain alkenyl group which may have a substituent as R 101 Preferably, it is a group exemplified as the chain alkenyl group as mentioned above.

[0095] The anion moiety that constitutes component (b-2) will be described below. In formula (b-2), R 104 , and R 105 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. Examples of these groups include R 101 The same groups as those shown in R 104 and R 105 may be bonded to each other to form a ring. R 104 , and R 105 As the alkyl group, an alkyl group which may have a substituent is preferable, and an alkyl group or a fluorinated alkyl group is more preferable. The alkyl group and the fluorinated alkyl group may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1 or more and 10 or less, more preferably 1 or more and 7 or less, and even more preferably 1 or more and 3 or less. 104 , and R 105 The number of carbon atoms in the alkyl group as R is preferably as small as possible, since the onium salt acid generator (B2) is easily dissolved in a solvent. 104 , and R 105 Regarding the fluorinated alkyl group as the alkyl group, the more hydrogen atoms substituted with fluorine atoms, the more preferable, in terms of high acid strength and high transparency to high-energy light and electron beams with a wavelength of 250 nm or less. The ratio of fluorine atoms in the fluorinated alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%. Most preferably, it is a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103each independently represents a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). 101 and the like. In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0096] (cation part) In formula (b-1), formula (b-2), and formula (b-3), M' m+ represents an onium cation having a valence of m. The onium cation is preferably a sulfonium cation. m is an integer of 1 or greater.

[0097] M' m+ The organic cation represented by the formula (I) is not particularly limited, and any organic cation known to be a cationic moiety constituting a conventional onium salt-type acid generator can be appropriately used. As such a cationic moiety, a sulfonium cation is preferred. Specific examples include sulfonium cations represented by the following formula (bc-1) or (bc-2). [ka] (In formulas (bc-1) and (bc-2), R bc1 ~R bc8 R each independently represents an aryl group, an alkyl group, a cycloalkyl group, or an alkenyl group which may have a substituent. bc1 ~R bc5 may be bonded to each other to form a ring together with the sulfur atom in the formula. bc6 ~R bc7 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. bc8 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an SO 2 -containing cyclic group. bc1 represents -C(=O)- or -C(=O)-O-.

[0098] In formulas (bc-1) and (bc-2), R bc1 ~R bc5 The aryl group as the aryl group includes an unsubstituted aryl group having a carbon atom number of 6 to 20. As the unsubstituted aryl group, a phenyl group and a naphthyl group are preferable. R bc1 ~R bc5 The alkyl group preferably has 1 or more and 30 or less carbon atoms. R bc1 ~R bc5 The cycloalkyl group preferably has 3 or more and 30 or less carbon atoms. R bc1 ~R bc5 The alkenyl group as the alkyl group preferably has 2 or more and 10 or less carbon atoms. R bc1 ~R bc5 , and R bc8 Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following formulas (bc-r-1) to (bc-r-7), respectively.

[0099] [ka] (In formulas (bc-r-1) to (bc-r-7), R' b11 are each independently a hydrogen atom, a cyclic group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent.

[0100] R' b11 The cyclic group as the cyclic group is preferably a cyclic hydrocarbon group. The cyclic hydrocarbon group may be an aromatic hydrocarbon group, an alicyclic hydrocarbon group, or a group containing an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. The alicyclic hydrocarbon group may be saturated or unsaturated. The alicyclic hydrocarbon group is preferably a saturated alicyclic hydrocarbon group.

[0101] R' b11The number of carbon atoms in the aromatic hydrocarbon group as is preferably 3 or more and 30 or less, more preferably 5 or more and 30 or less, even more preferably 5 or more and 20 or less, particularly preferably 6 or more and 15 or less, and most preferably 6 or more and 10 or less, provided that the number of carbon atoms does not include the number of carbon atoms of the substituent.

[0102] R' b11 Specific examples of the aromatic hydrocarbon ring contained in the aromatic hydrocarbon group as the aromatic ring include a benzene ring, a fluorene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a biphenyl ring.

[0103] R' b11 The cyclic group as may contain an aromatic heterocycle in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0104] R' b11 Specific examples of the aromatic hydrocarbon group as the alkyl group include a phenyl group, a naphthalene-1-yl group, a naphthalene-2-yl group, a 4-phenylphenyl group, a 3-phenylphenyl group, and a 2-phenylphenyl group.

[0105] R' b11 The alicyclic hydrocarbon group as the alkyl group preferably has 3 or more and 20 or less, and more preferably has 3 or more and 12 or less, carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is a cycloalkyl group. The number of carbon atoms of the cycloalkyl group is preferably 3 or more and 6 or less. Suitable specific examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane. The number of carbon atoms of the polycycloalkane is preferably 7 or more and 30 or less. Suitable specific examples of the polycycloalkane include polycycloalkanes having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system such as a ring group having a steroid skeleton.

[0106] Among them, R' b11 As the alicyclic hydrocarbon group as , an adamantyl group and a norbornyl group are preferred, and an adamantyl group is more preferred.

[0107] R' b11 The cyclic hydrocarbon group as may be a heterocycle containing a heteroatom. Specifically, lactone-containing cyclic groups, -SO 2 -containing cyclic groups, and other heterocyclic groups.

[0108] R' in formulas (bc-r-1) to (bc-r-7) b11 Examples of the substituent in the cyclic group as the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and still more preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with halogen atoms. The carbonyl group as a substituent is a methylene group (-CH 2 -) is a group that substitutes

[0109] R' b11 The alkyl group as may be either linear or branched. The linear alkyl group preferably has 1 or more and 20 or less carbon atoms, more preferably has 1 or more and 15 or less carbon atoms, and further preferably has 1 or more and 10 or less carbon atoms. The branched alkyl has preferably 3 or more and 20 or less carbon atoms, more preferably 3 or more and 15 or less, and even more preferably 3 or more and 10 or less carbon atoms. Specific examples of branched alkyl groups include an isopropyl group, a sec-butyl group, an isobutyl group, a sec-pentyl group, a 2-methylbutyl group, an isopentyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0110] R' b11 The alkenyl group as may be either linear or branched. The linear alkenyl group preferably has 2 or more and 10 or less carbon atoms, more preferably has 2 or more and 5 or less carbon atoms, further preferably has 2 or more and 4 or less carbon atoms, and particularly preferably has 3 carbon atoms. Specific examples of linear alkenyl groups include vinyl, 1-propenyl, 2-propenyl (allyl), and butenyl groups. Specific examples of branched alkenyl groups include a 1-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. As the alkenyl group, a straight-chain alkenyl group is preferable, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

[0111] R' b11 Examples of the substituent that the alkyl group and alkenyl group may have as R' include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R' b11 Examples of the cyclic groups include the cyclic groups represented by the formula (I).

[0112] Among them, R' b11 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group, -SO represented by the formulas (b-r2-1) to (b-r2-4) are 2 -containing cyclic groups and the like are preferred.

[0113] R in formula (bc-1) or (bc-2) bc1 ~R bc3 When two of the above are bonded to each other to form a ring with the sulfur atom in the formula, heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, carbonyl groups, -SO-, -SO 2 -, -SO 3 The rings may be bonded via a functional group such as -, -COO-, -CONH-, or -N(RN)- (RN is an alkyl group having 1 to 5 carbon atoms). As for the ring formed, one ring containing a sulfur atom in its ring skeleton in the formula is preferably a 3- to 10-membered ring including the sulfur atom, and particularly preferably a 5- to 7-membered ring. Specific examples of the ring include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0114] R bc6 ~R bc7 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. bc6 ~R bc7 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. bc6 , and R bc7 When both are alkyl groups, R bc6 , and R bc7 may be bonded to each other to form a ring.

[0115] R bc8 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an SO 2 -containing cyclic group. R bc8 When is an aryl group, the aryl group is preferably an unsubstituted aryl group having 6 to 20 carbon atoms, and more preferably a phenyl group, a naphthalene-1-yl group, or a naphthalene-2-yl group. R bc8 When is an alkyl group, the alkyl group may be a chain or cyclic alkyl group. The alkyl group preferably has 1 to 30 carbon atoms. R bc8 When is an alkenyl group, the alkenyl group preferably has 2 or more and 10 or less carbon atoms. R bc8 SO which may have a substituent as 2 The -containing cyclic group is preferably "-SO 2 -containing polycyclic group".

[0116] Preferred cations represented by formula (bc-1) are shown below.

[0117] [ka]

[0118] [ka]

[0119] [ka] (In formulas (bc-1-35) to (bc-1-37), g1, g2, and g3 represent the number of repetitions of the group in parentheses, g1 is an integer of 1 or more and 5, g2 is an integer of 0 or more and 20 or less, and g3 is an integer of 0 or more and 20 or less.)

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka] (In the formula, R” b11 is a hydrogen atom or a substituent, and the substituent is R bc1 ~R bc5 , and R bc8 The substituents are the same as those that may be possessed by

[0124] [ka]

[0125] Preferred specific examples of the cation represented by formula (bc-2) include the cations represented by the following formulas (bc-2-1) to (bc-2-6).

[0126] [ka]

[0127] The cation moiety of the onium salt photoacid generator (B2) is represented by formulas (bc-1) and (bc-2). Among them, the cations represented by formulas (bc-1-1) to (bc-1-6) and (bc-1-52) to (bc-1-60) are preferred.

[0128] Among the above onium salt-type photoacid generators (B2), the compound represented by the following formula (b-1-1) is preferred.

[0129] [ka] (In formula (b-1-1), R b1 ~R b3 R each independently represents an aryl group which may have a substituent. b1 ~R b3 Any two of R may be bonded to each other to form a ring together with the sulfur atom in the formula. 101 R is an optionally substituted cyclic group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 102 is a fluorine atom or a fluorine-containing alkyl group having 1 to 5 carbon atoms. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 is a single bond or an oxygen atom.

[0130] In formula (b-1-1), R 101 , Y 101 ,V 101 , and R 102 is R in formula (b-1) 101 , Y 101 ,V 101 , and R 102 is the same as: R b1 ~R b3 R is an aryl group which may have a substituent. b1 ~R b3 Any two of R may be bonded to each other to form a ring together with the sulfur atom in the formula. b1 ~R b3The aryl group in the formula (bc-1) is R bc1 ~R bc3 The substituent that the aryl group may have is the same as that of the aryl group in the above formula (bc-1). bc1 ~R bc3 The substituents are the same as those that the aryl group in the above formula (I) may have. R b1 ~R b3 The ring formed by combining any two of these with the sulfur atom in the formula is R bc1 ~R bc3 The rings formed by bonding together with the sulfur atom in the formula are the same as those in the formula.

[0131] In the photosensitive resin composition, the photoacid generator (B) may be used alone or in combination of two or more kinds. The content of the photoacid generator (B) in the photosensitive resin composition is 0.5 parts by mass or more and 30 parts by mass or less, preferably 0.5 parts by mass or more and 15 parts by mass or less, and more preferably 1 part by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the polyhydroxystyrene resin (A). When the content of the photoacid generator (B) is within the above range, a photosensitive resin composition having particularly good photolithography properties is easily obtained.

[0132] <Crosslinking agent (C)> The photosensitive resin composition contains a crosslinking agent (C). The crosslinking agent (C) is a multifunctional epoxy compound (C1) having two or more epoxy groups. The multifunctional epoxy compound (C1) reacts with a phenolic hydroxyl group of the polyhydroxystyrene resin (A) to crosslink the polyhydroxystyrene resin (A). The multifunctional epoxy compound (C1) is not particularly limited as long as the desired effect is not impaired.

[0133] Examples of the polyfunctional epoxy compound (C1) include bifunctional epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AD ​​type epoxy resins, naphthalene type epoxy resins, and biphenyl type epoxy resins; glycidyl ester type epoxy resins such as dimer acid glycidyl ester and triglycidyl ester; glycidyl amine type epoxy resins such as tetraglycidylaminodiphenylmethane, triglycidyl-p-aminophenol, tetraglycidylmeta-xylylenediamine, and tetraglycidylbisaminomethylcyclohexane; heterocyclic epoxy resins such as triglycidyl isocyanurate; phloroglucinol triglycidyl ether, trihydroxybiphenyl triglycidyl ether, trihydric trifunctional epoxy resins such as 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-(2,3-epoxypropoxy)phenyl]ethyl]phenyl]propane, and 1,3-bis[4-[1-[4-(2,3-epoxypropoxy)phenyl]-1-[4-[1-[4-(2,3-epoxypropoxy)phenyl]-1-methylethyl]phenyl]ethyl]phenoxy]-2-propanol; and tetrafunctional epoxy resins such as pentaerythritol tetraglycidyl ether, tetrahydroxyphenylethane tetraglycidyl ether, tetraglycidyl benzophenone, bisresorcinol tetraglycidyl ether, and tetraglycidoxybiphenyl.

[0134] The amount of the crosslinking agent (C) used is not particularly limited as long as the photosensitive resin composition is cured well. For example, the amount of the crosslinking agent (C) used is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or more, and even more preferably 2 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the polyhydroxystyrene resin.

[0135] <Thermal acid generator (D)> The photosensitive resin composition may further contain a thermal acid generator (D). When the photosensitive resin composition contains the thermal acid generator (D), the crosslinking reaction between the polyhydroxystyrene resin (A) and the crosslinking agent (C) proceeds particularly well due to the action of the acid generated by heat when the photosensitive resin composition is heated. As the thermal acid generator (D), for example, a thermal acid generator having a decomposition onset temperature of 120 to 200°C can be mentioned. The thermal acid generator (D) can be used alone or in combination of two or more kinds.

[0136] The thermal acid generator (D) preferably contains a thermal acid generator that is composed of a cationic moiety and an anionic moiety, and the cationic moiety is a cation represented by the following formula (dc): By using such a thermal acid generator, the acid-dissociable group is more easily eliminated from the resin (A), and therefore a phenolic hydroxyl group or a carboxyl group is more easily generated, and as a result, the curability of the curable resin composition is easily improved.

[0137] [ka] (In formula (dc), R dc1 , R dc2 , and R dc3 are each independently an alkyl group having 1 to 6 carbon atoms.

[0138] In formula (dc), R dc1 , R dc2 , and R dc3 Suitable examples of the alkyl group as R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. As the alkyl group, a methyl group or an ethyl group is preferable, and a methyl group is more preferable. d01 , R d02 , and R d03 It is particularly preferable that all of are methyl groups.

[0139] That is, the cation represented by formula (dc) is preferably a cation represented by the following formula (dc-1). [ka]

[0140] Examples of the counter anion to the cation represented by formula (dc) include AsF 6 - , SbF 6 - , P.F. 6 - , C.F. 3 SO 3 - , anions represented by the following formula (da-1), and anions represented by the following formula (da-2).

[0141] [ka] (In formula (da-1), R da1 , R da2 , R da3 , and R da4 each independently represents a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent; R da1 , R da2 , R da3 , and R da4 At least one of the above is an aromatic hydrocarbon group which may have a substituent.

[0142] [ka] (In formula (da-2), R da5 , R da6 , R da7 , and R da8 each independently represents a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent; R da5 , R da6 , R da7 , and R da8 At least one of the above is an aromatic hydrocarbon group which may have a substituent.

[0143] R in formula (da-1) da1 ~Rda4 The number of carbon atoms in the hydrocarbon group or heterocyclic group as the substituent is not particularly limited, but is preferably 1 or more and 50 or less, more preferably 1 or more and 30 or less, and particularly preferably 1 or more and 20 or less.

[0144] R da1 ~R da4 Specific examples of the hydrocarbon group as the alkyl group include a linear or branched alkyl group, a linear or branched alkenyl group, a linear or branched alkynyl group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and an aralkyl group. As mentioned above, R da1 ~R da4 At least one of R is an aromatic group which may have a substituent. da1 ~R da4 More preferably, three or more of R are aromatic groups which may have a substituent. da1 ~R da4 It is particularly preferred that all of the radicals are aromatic groups which may have a substituent.

[0145] R da1 ~R da4 Examples of the substituent that the hydrocarbon group or heterocyclic group may have as the substituent include a halogenated alkyl group having from 1 to 18 carbon atoms, a halogenated aliphatic cyclic group having from 3 to 18 carbon atoms, a nitro group, a hydroxyl group, a cyano group, an alkoxy group having from 1 to 18 carbon atoms, an aryloxy group having from 6 to 14 carbon atoms, an aliphatic acyl group having from 2 to 19 carbon atoms, an aromatic acyl group having from 7 to 15 carbon atoms, an aliphatic acyloxy group having from 2 to 19 carbon atoms, an aromatic acyloxy group having from 7 to 15 carbon atoms, an alkylthio group having from 1 to 18 carbon atoms, an arylthio group having from 6 to 14 carbon atoms, an amino group in which one or two hydrogen atoms bonded to the nitrogen atom may be substituted with a hydrocarbon group having from 1 to 18 carbon atoms, and a halogen atom. R da1 ~R da4When the hydrocarbon group as represented by is an aromatic hydrocarbon group, the aromatic hydrocarbon group may be substituted with one or more substituents selected from the group consisting of an alkyl group having from 1 to 18 carbon atoms, an alkenyl group having from 2 to 18 carbon atoms, and an alkynyl group having from 2 to 18 carbon atoms.

[0146] R da1 ~R da4 When the hydrocarbon group as has a substituent, the number of the substituents is not particularly limited and may be 1 or more than 2. When the number of the substituents is more than one, the multiple substituents may be the same or different.

[0147] R da1 ~R da4 When is an alkyl group, preferred specific examples include straight-chain alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, and an n-icosyl group; and branched-chain alkyl groups such as an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, an isohexyl group, a 2-ethylhexyl group, and a 1,1,3,3-tetramethylbutyl group.

[0148] R da1 ~R da4 When is an alkenyl group or an alkynyl group, preferred examples include alkenyl groups and alkynyl groups corresponding to the above groups preferred as the alkyl group.

[0149] R da1 ~R da4 When is an aromatic hydrocarbon group, preferred examples include a phenyl group, an α-naphthyl group, a β-naphthyl group, a biphenyl-4-yl group, a biphenyl-3-yl group, a biphenyl-2-yl group, an anthryl group, and a phenanthryl group.

[0150] R da1 ~R da4 Preferred examples of the alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group; and bridged aliphatic cyclic hydrocarbon groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group, and a pinanyl group.

[0151] R da1 ~R da4 When is an aralkyl group, preferred examples thereof include a benzyl group, a phenethyl group, an α-naphthylmethyl group, a β-naphthylmethyl group, an α-naphthylethyl group, and a β-naphthylethyl group.

[0152] R da1 ~R da4 Preferred examples of the heterocyclic group include a thienyl group, a furanyl group, a selenophenyl group, a pyranyl group, a pyrrolyl group, an oxazolyl group, a thiazolyl group, a pyridyl group, a pyrimidyl group, a pyrazinyl group, an indolyl group, a benzofuranyl group, a benzothienyl group, a quinolyl group, an isoquinolyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, an acridinyl group, a phenothiazinyl group, a phenazinyl group, a xanthenyl group, a thianthrenyl group, a phenoxazinyl group, a phenoxathiinyl group, a chromanyl group, an isochromanyl group, a dibenzothienyl group, a xanthonyl group, a thioxanthonyl group, and a dibenzofuranyl group.

[0153] R in formula (da-2) da5 ~R da8 As for R in formula (da-1), da1 ~R da4 The same groups as those mentioned above with respect to the group may be mentioned.

[0154] Preferable specific examples of the anion moiety represented by formula (da-1) described above include: tetrakis(4-nonafluorobiphenyl)gallium anion, tetrakis(1-heptafluoronaphthyl)gallium anion, tetrakis(pentafluorophenyl)gallium anion, tetrakis(3,4,5-trifluorophenyl)gallate anion, Tetrakis(2-nonaphenylbiphenyl)gallium anion, tetrakis(2-heptafluoronaphthyl)gallium anion, tetrakis(7-nonafluoroanthryl)gallium anion, Tetrakis(4'-(methoxy)octafluorobiphenyl)gallium anion, tetrakis(2,4,6-tris(trifluoromethyl)phenyl)gallium anion, tetrakis(3,5-bis(trifluoromethyl)phenyl)gallium anion, tetrakis(2,3-bis(pentafluoroethyl)naphthyl)gallium anion, tetrakis(2-isopropoxy-hexafluoronaphthyl)gallium anion, tetrakis(9,10-bis(heptafluoropropyl)heptafluoroanthryl)gallium anion, Tetrakis(9-nonafluorophenanthryl)gallate anion, Tetrakis(4-[tri(isopropyl)silyl]-tetrafluorophenyl)gallium anion, Tetrakis(9,10-bis(p-tolyl)-heptafluorophenanthryl)gallium anion, Tetrakis(4-[dimethyl(t-butyl)silyl]-tetrafluorophenyl)gallium anion, Monophenyltris(pentafluorophenyl)gallium anion, and Examples of the anion include monoperfluorobutyltris(pentafluorophenyl)gallium anion, and more preferably, the following anions are listed.

[0155] [ka]

[0156] Preferable specific examples of the anion moiety represented by formula (da-2) include: Tetrakis(4-nonafluorobiphenyl)boron anion, Tetrakis(1-heptafluoronaphthyl)boron anion, tetrakis(pentafluorophenyl)boron anion, tetrakis(3,4,5-trifluorophenyl)boron anion, Tetrakis(2-nonaphenylbiphenyl)boron anion, Tetrakis(2-heptafluoronaphthyl)boron anion, Tetrakis(7-nonafluoroanthryl)boron anion, Tetrakis(4'-(methoxy)octafluorobiphenyl)boron anion, Tetrakis(2,4,6-tris(trifluoromethyl)phenyl)boron anion, Tetrakis(3,5-bis(trifluoromethyl)phenyl)boron anion, Tetrakis(2,3-bis(pentafluoroethyl)naphthyl)boron anion, tetrakis(2-isopropoxy-hexafluoronaphthyl)boron anion, Tetrakis(9,10-bis(heptafluoropropyl)heptafluoroanthryl)boron anion, Tetrakis(9-nonafluorophenanthryl)boron anion, Tetrakis(4-[tri(isopropyl)silyl]-tetrafluorophenyl)boron anion, Tetrakis(9,10-bis(p-tolyl)-heptafluorophenanthryl)boron anion, Tetrakis(4-[dimethyl(t-butyl)silyl]-tetrafluorophenyl)boron anion, monophenyltris(pentafluorophenyl)boron anion, and Examples of the anion include monoperfluorobutyltris(pentafluorophenyl)boron anion, and more preferably, the following anions are included:

[0157] [ka]

[0158] Among the counter anions listed above, CF 3 SO 3 - and ((C 6 F 5 ) 4 B) - It is preferable to use "C 6 F 5 " represents a pentafluorophenyl group.

[0159] A preferred specific example of a compound having a cation moiety composed of a cation represented by formula (dc) and an anion moiety is a compound having a cation represented by formula (dc-1) and AsF 6 - A quaternary ammonium salt consisting of a cation represented by formula (dc-1) and SbF 6 - A quaternary ammonium salt consisting of a cation represented by formula (dc-1) and PF 6 - A quaternary ammonium salt consisting of a cation represented by formula (dc-1) and CF 3 SO 3 - and a quaternary ammonium salt consisting of a cation represented by formula (dc-1) and ((C 6 F 5 ) 4 B) - Among these, quaternary ammonium salts consisting of a cation represented by formula (dc-1) and CF 3 SO 3 - and a quaternary ammonium salt consisting of a cation represented by formula (dc-1) and ((C 6 F 5 ) 4 B) -Quaternary ammonium salts consisting of the above are more preferred.

[0160] The content of the thermal acid generator (D) in the photosensitive resin composition is not particularly limited as long as it does not impair the object of the present invention. The content of the thermal acid generator (D) in the photosensitive resin composition is preferably 0.1 parts by mass or more and 15 parts by mass or less, more preferably 0.3 parts by mass or more and 10 parts by mass or less, and particularly preferably 0.4 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the resin (A).

[0161] <Organic solvent (S)> The photosensitive resin composition may contain an organic solvent (S). When the photosensitive resin composition contains an organic solvent (S), it is easy to adjust the coating property of the photosensitive resin composition and the film thickness of the positive photosensitive resin composition layer formed using the photosensitive resin composition. The organic solvent (S) may be used alone or in combination of two or more kinds.

[0162] Specific examples of the organic solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and dipropylene glycol monoacetate, as well as monomethyl ethers thereof (e.g., propylene glycol monomethyl ether acetate), monoethyl ether, monopropyl ether, monobutyl ether, and monophenyl ether; and derivatives thereof; cyclic ethers such as dioxane; esters such as ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyethyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, and 3-methyl-3-methoxybutyl acetate; and aromatic hydrocarbons such as toluene and xylene.

[0163] In the photosensitive resin composition, the content of the organic solvent (S) is preferably 50 parts by mass or more and 3,000 parts by mass or less, and more preferably 100 parts by mass or more and 2,000 parts by mass or less, relative to 100 parts by mass of the polyhydroxystyrene resin (A). When the content is within the above range, the coatability of the photosensitive resin composition is likely to be improved, and the thickness of the coating film formed using the photosensitive resin composition is easily adjusted.

[0164] <Other ingredients> The photosensitive resin composition may contain various additives in addition to the above components, as long as the desired effect is not impaired. The additives may be appropriately selected from various additives that have been conventionally blended into photosensitive resin compositions. Specific examples of other components include a quencher, a polyvinyl resin, a surfactant, and an acid or an acid anhydride.

[0165] The photosensitive resin composition may contain a quencher. As the quencher, a low molecular weight compound (non-polymer) is usually used. As the quencher, for example, amines such as aliphatic amines and aromatic amines can be mentioned. As the quencher, aliphatic amines are preferable, and secondary aliphatic amines and tertiary aliphatic amines are particularly preferable. Here, the aliphatic amine is an amine having one or more aliphatic groups. The number of carbon atoms of the aliphatic group of the aliphatic amine is preferably 1 or more and 20 or less.

[0166] Examples of aliphatic amines include ammonia (NH 3 ), alkylamines in which at least one hydrogen atom is substituted with an alkyl group having 20 or less carbon atoms, ammonia (NH 3 ) alkanolamines in which at least one hydrogen atom is substituted with a hydroxyalkyl group, and cyclic amines.

[0167] Specific examples of alkylamines and alkanolamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkanolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, stearyldiethanolamine, and lauryldiethanolamine. Of these, trialkylamines and alkanolamines are preferred.

[0168] Examples of the cyclic amine include nitrogen-containing heterocyclic compounds. The nitrogen-containing heterocyclic compounds may be monocyclic aliphatic amines or polycyclic aliphatic amines.

[0169] Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The number of carbon atoms of the aliphatic polycyclic amine is preferably 6 or more and 10 or less. Specific examples of the aliphatic polycyclic amine include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0170] Specific examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, and tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine.

[0171] Specific examples of aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, 2,2'-dipyridyl, and 4,4'-dipyridyl.

[0172] The quencher may be used alone or in combination of two or more kinds. The amount of the quencher contained in the photosensitive resin composition is preferably 0.01 parts by mass or more and 5.0 parts by mass or less based on 100 parts by mass of the polyhydroxystyrene resin (A).

[0173] The photosensitive resin composition may contain a polyvinyl resin in order to improve the plasticity of the coating film formed. Specific examples of the polyvinyl resin include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoic acid, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylphenol, and copolymers thereof.

[0174] The photosensitive resin composition may contain an adhesion aid in order to improve adhesion to a support.

[0175] The photosensitive resin composition may contain a surfactant to improve coating properties, defoaming properties, leveling properties, etc. Specific examples of surfactants include BM-1000, BM-1100 (all manufactured by BM Chemie), Megafac F142D, Megafac F172, Megafac F173, Megafac F183 (all manufactured by DIC Corporation), Fluorad FC-135, Fluorad FC-170C, Fluorad FC-430, Fluorad FC-431 (all manufactured by Sumitomo 3M Limited), Surflon S-112, Surflon S-113, Surflon Examples of commercially available fluorine-based surfactants include, but are not limited to, commercially available fluorine-based surfactants such as S-131, Surflon S-141, Surflon S-145 (all manufactured by Asahi Glass Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (all manufactured by Toray Silicones Co., Ltd.), Polyfox PF-136A, Polyfox PF-156A, Polyfox PF-151N, Polyfox PF-636, Polyfox PF-656, Polyfox PF-6520 (all manufactured by OMNOVA Solutions).

[0176] The photosensitive resin composition may contain an acid or an acid anhydride in order to finely adjust the solubility in the developer.

[0177] Specific examples of acids and acid anhydrides include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, and cinnamic acid; hydroxymonocarboxylic acids such as lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid, and syringic acid; oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, butanetetracarboxylic acid, and trimellitic acid. Examples of the acid anhydride include polyvalent carboxylic acids such as itaconic anhydride, pyromellitic anhydride, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, and 1,2,5,8-naphthalenetetracarboxylic acid; and acid anhydrides such as itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenylsuccinic anhydride, tricarbanilic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, himic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bistrimellitate anhydride, and glycerin tristrimellitate anhydride.

[0178] <Method for producing photosensitive resin composition> The photosensitive resin composition can be prepared by mixing and stirring the above-mentioned components by a conventional method. If necessary, dispersion and mixing may be performed using a dispersing machine such as a dissolver, homogenizer, or three-roll mill. After mixing, the components may be filtered using a mesh, membrane filter, or the like.

[0179] ≪Cured product≫ By heating the photosensitive resin composition, the polyhydroxystyrene resin (A) is crosslinked by the crosslinking agent (C) to form a cured product. Such a cured product has excellent chemical resistance.

[0180] <Method for manufacturing optical elements> As described above, the photosensitive resin composition gives a cured product having excellent chemical resistance when heated. Therefore, the photosensitive resin composition is preferably used in a manufacturing method of an optical element having a plurality of microlenses including n kinds of microlenses on a substrate. In such a manufacturing method, the cured product of the photosensitive resin composition frequently comes into contact with a chemical solution such as an organic solvent. The n types of microlenses are different from each other. The points in which the n types of microlenses are different from each other are not particularly limited. For example, the n types of microlenses are different from each other in one or more of optical properties such as refractive index and light transmittance, chemical properties such as solvent resistance and chemical resistance, mechanical properties such as hardness and elastic modulus, chemical composition of the material constituting the microlens, size, shape, etc. Typically, the n types of microlenses are different from each other in size.

[0181] Hereinafter, a method for manufacturing an optical element having a plurality of microlenses, including n types of microlenses, on a substrate will be described.

[0182] In the above manufacturing method, n is an integer of 2 or more. n is preferably an integer of 2 or more and 4 or less, more preferably 2 or 3, and particularly preferably 2. In other words, an optical element provided with two types of microlenses is preferably manufactured.

[0183] The manufacturing method includes forming a resin film on a substrate; forming a mask on the resin film having a shape corresponding to the shapes of the plurality of microlenses; The method includes etching the resin film with a mask to form a plurality of microlenses to which the shape of the mask is transferred.

[0184] The resin film is formed as a lens material layer on a substrate, which may be an image element including a photodiode (organic photodiode, inorganic photodiode, etc.), a silicon wafer provided with a color filter layer, or a silicon wafer optionally further provided with an anti-reflection film.

[0185] Next, a mask having a shape corresponding to the shape of the multiple microlenses is formed on the resin film. The masks are as follows (i) to (iii): (i) applying an m-th photosensitive resin composition onto the resin film to form an m-th coating film; (ii) exposing and developing the m-th coating film to form an m-th dot at a position on the substrate corresponding to a position where the m-th microlens is to be formed; (iii) heating the m-th dot to deform the m-th dot into a shape corresponding to the shape of the m-th microlens; It is formed by repeating the above operation n times. The m in the above is an integer between 1 and n, The first to nth photosensitive resin compositions used in forming the mask may be the same or different. At least one of the first to nth photosensitive resin compositions is the above-mentioned photosensitive resin composition.

[0186] A method for forming a mask having a microlens shape on a resin film for forming the first microlens will be described below. First, a first photosensitive resin composition is applied onto a resin film to form a first coating film. As the first photosensitive resin composition, a photosensitive resin composition used for forming a microlens-shaped mask in the above-mentioned etch-back method can be used without any particular limitation. As the first photosensitive resin composition, the above-mentioned photosensitive resin composition is preferable.

[0187] The method for applying the first photosensitive resin composition is not particularly limited. For example, the first photosensitive resin composition can be applied to a desired thickness using a contact transfer type application device such as a roll coater, a reverse coater, a bar coater, or a slit coater, or a non-contact type application device such as a spinner (rotary application device) or a curtain flow coater to form a first coating film.

[0188] The first coating film made of the photosensitive resin composition may be appropriately subjected to a heat treatment (pre-bake (post-apply bake (PAB)) treatment) to remove the solvent in the first coating film. The conditions of the heat treatment vary depending on the types of components of the photosensitive resin composition, the blending ratio, the coating film thickness, etc. The heating temperature is, for example, preferably 60° C. to 150° C., and more preferably 70° C. to 140° C. The heating time is, for example, preferably 0.5 minutes to 60 minutes, and more preferably 1 minute to 50 minutes. The thickness of the first coating film is preferably in the range of 100 nm or more and 4.0 μm or less, and more preferably in the range of 400 nm or more and 2.0 μm or less.

[0189] Next, the first coating film is exposed and developed to form first dots at positions on the substrate corresponding to the positions where the first microlenses are to be formed.

[0190] The exposure is carried out position-selectively so that the first dot is formed at a predetermined position. The position-selective exposure can be carried out, for example, through a desired mask pattern. The wavelength of the light used for the exposure is not particularly limited. The exposure can be carried out using radiation such as KrF excimer laser, ArF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays.

[0191] The first coating film that has been exposed is then developed, thereby dissolving and removing unnecessary portions. It is preferable that the coating film is not heated after exposure and before development.

[0192] In the case of an alkaline development process, development is carried out using an alkaline developer, whereas in the case of a solvent development process, development is carried out using a developer containing an organic solvent (organic developer).

[0193] As the alkaline developer, for example, an aqueous solution of an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane, etc. can be used. In addition, an aqueous solution of the above-mentioned alkaline solution can be used as the developer by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant. As the alkaline developer, an aqueous solution of tetramethylammonium hydroxide having a concentration of 0.1% by mass or more and 10% by mass or less is preferable.

[0194] The organic developer may be any organic solvent capable of dissolving the polyhydroxystyrene resin (A) (polyhydroxystyrene resin (A) before exposure). The organic solvent used as the organic developer may be appropriately selected from known organic solvents. Suitable examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0195] Ketone-based solvents are organic solvents having a structure represented by CC(=O)-C. Ester-based solvents are organic solvents having a carboxylic acid ester group. Alcohol-based solvents are organic solvents having an alcoholic hydroxyl group. Nitrile-based solvents are organic solvents having a nitrile group. Amide-based solvents are organic solvents containing a carboxylic acid amide group. The nitrogen atom in the carboxylic acid amide group may be substituted with an organic group, preferably a hydrocarbon group. Ether-based solvents are organic solvents having an ether bond.

[0196] Some organic solvents contain multiple types of functional groups that characterize the above-mentioned solvents in their structures, and in such cases, the organic solvent is considered to fall under any of the solvent types that contain the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether is considered to fall under both the alcohol-based solvents and the ether-based solvents in the above classification. The hydrocarbon solvent is a hydrocarbon solvent that is composed of a hydrocarbon that may be halogenated and has no substituents other than halogen atoms. The halogen atom is preferably a fluorine atom. Of the above, the organic solvent contained in the organic developer is preferably a polar solvent, and more preferably a ketone-based solvent, an ester-based solvent, or a nitrile-based solvent.

[0197] The developing time varies depending on the composition of the first photosensitive resin composition, the thickness of the first coating film, etc., but is usually from 20 seconds to 5 minutes. The developing method may be any of a puddle method, a dipping method, a paddle method, a spray developing method, etc.

[0198] The developed first coating film is washed with running water or the like as necessary, and then dried. In this manner, a dot pattern consisting of the first dots is formed.

[0199] Next, the first dots are heated to deform the first dots into a shape corresponding to the shape of the first microlens. In this manner, a mask having a shape corresponding to the shape of the first microlens can be formed on the resin film. The heating conditions vary depending on the types and blending ratios of each component in the first photosensitive resin composition, the coating film thickness, etc. For example, the heating temperature is preferably 100° C. or more and 200° C. or less, and more preferably 120° C. or more and 150° C. or less. The heating time is preferably 1 minute or more and 30 minutes or less, and more preferably 3 minutes or more and 10 minutes or less.

[0200] In this manner, a mask having a shape corresponding to the shape of the first microlens is formed on the resin film.

[0201] Next, a mask having a shape corresponding to the shape of the second microlens is formed on the resin film having a mask on its surface having a shape corresponding to the shape of the first microlens by using a second photosensitive resin composition. The method for forming the mask having a shape corresponding to the shape of the second microlens is the same as the method for forming the mask having a shape corresponding to the shape of the first microlens. The second photosensitive resin composition is preferably the above-mentioned first photosensitive resin composition.

[0202] By repeating such an operation n times, n types of masks corresponding to the shapes of n types of microlenses are formed on the resin film. By carrying out etching on the resin film having the n types of masks so that the resin film is etched together with the masks, a plurality of microlenses to which the shapes of the n types of masks are transferred are formed on the base material.

[0203] As described above, the present inventors provide the following (1) to (9). (1) A photosensitive resin composition comprising a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation, and a crosslinking agent (C), In the polyhydrostyrene resin (A), a part of the phenolic hydroxyl groups is protected by an acetal-type protecting group, The crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups; Photosensitive resin composition. (2) The photosensitive resin composition according to (1), further comprising a thermal acid generator (D). (3) The photosensitive resin composition according to (1) or (2), wherein the photoacid generator (B) is a photoacid generator (Ba) that generates an acid in response to actinic rays or radiation having a wavelength of 200 nm or more and 300 nm or less. (4) The photosensitive resin composition according to any one of (1) to (3), wherein the photoacid generator (B) comprises a diazomethane-type photoacid generator (B1) and / or an onium salt-type photoacid generator (B2). (5) The photosensitive resin composition according to any one of (1) to (4), comprising 1.0 part by mass or more and 20 parts by mass or less of a crosslinking agent (C) per 100 parts by mass of the polyhydroxystyrene resin (A). (6) A cured product of the photosensitive resin composition according to any one of (1) to (5). (7) A method for producing an optical element having a plurality of microlenses including n types of microlenses on a substrate, comprising the steps of: n is an integer of 2 or more, The manufacturing method includes forming a resin film on a substrate; forming a mask on the resin film having a shape corresponding to the shapes of the plurality of microlenses; and etching the resin film together with the mask to form a plurality of microlenses to which the shape of the mask is transferred. The mask is as follows: (i) to (iii): (i) applying an m-th photosensitive resin composition onto the resin film to form an m-th coating film; (ii) exposing and developing the m-th coating film to form an m-th dot at a position on the substrate corresponding to a position where the m-th microlens is to be formed; (iii) heating the m-th dot to deform the m-th dot into a shape corresponding to the shape of the m-th microlens; It is formed by repeating the above operation n times, m is an integer between 1 and n, The first to nth photosensitive resin compositions used in forming the mask may be the same or different, At least one of the first to nth photosensitive resin compositions is the photosensitive resin composition according to any one of (1) to (6), A production method in which, when a coating film is formed using the photosensitive resin composition according to any one of (1) to (6), the coating film is not heated after exposure and before development. (8) The method for producing an optical element according to (7), wherein n is 2. (9) The method for producing an optical element according to (8) or (9), wherein in forming the mask, the photosensitive resin composition that is first applied onto the resin film is a photosensitive resin composition. EXAMPLES

[0204] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0205] [Examples 1 to 8, Comparative Examples 1 and 2] In the examples and comparative examples, resin A-1 consisting of the following units was used as the polyhydroxystyrene resin (A). The weight average molecular weight (Mw) of Resin A-1, calculated based on polystyrene, measured by gel permeation chromatography, is 20,000. The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of Resin A-1 is 1.1.

[0206] [ka]

[0207] In the examples and comparative examples, the following B1-1 was used as the diazomethane-type acid generator (B1). B1-1: Bis(cyclohexylsulfonyl)diazomethane was used. In the examples and comparative examples, the following B2-1 was used as the onium salt-type acid generator (B2). [ka]

[0208] In the examples and comparative examples, the following compounds C-1 to C-3 were used as the crosslinking agent (C). [ka]

[0209] In the examples and comparative examples, the following compounds D-1 and D-2 were used as the thermal acid generator (D). [ka]

[0210] 100 parts by mass of resin (A) of the type shown in Table 1, photoacid generator (B) of the type and amount shown in Table 1, crosslinker (C) and thermal acid generator (D) in the amounts shown in Table 1 were dissolved in a mixed solvent (propylene glycol monomethyl ether acetate / ethyl lactate = 60 / 40 (mass ratio)) to a solid concentration of 10 wt%, to obtain photosensitive resin compositions for each Example and Comparative Example.

[0211] The patterning characteristics of the photosensitive resin composition and the chemical resistance of the cured film were evaluated using the obtained photosensitive resin composition according to the following methods. The evaluation results are shown in Table 1.

[0212] <Patterning characteristic evaluation> A silicon substrate having a 0.16 μm thick lower anti-reflection film and a 1 μm thick cured film of thermosetting acrylic resin on its surface was coated with the photosensitive resin composition of each Example and Comparative Example on the cured film of acrylic resin using a spin coater. The photosensitive resin composition coated on the silicon substrate was baked at 100° C. for 60 seconds to obtain a coating film with a thickness of 550 nm. The formed coating film was exposed to a KrF excimer laser (NSR-S203, manufactured by Nikon Corporation) at NA / s=0.68 / 0.75 through a mask for forming a dot pattern with a dot diameter of 0.40 μm and a dot interval of 0.30 μm. The coating film after exposure was developed by contacting it with an aqueous solution of tetramethylammonium hydroxide having a concentration of 2.38% by mass at room temperature for 60 seconds. After development, the pattern shape formed on the silicon substrate was observed from above and in the cross-sectional direction using a scanning electron microscope (SEM), and the patterning characteristics were evaluated according to the following criteria. A: It was possible to resolve the image. C: Resolution was not possible.

[0213] <Chemical resistance evaluation> A silicon substrate having a 0.16 μm thick lower anti-reflection film and a 1 μm thick cured film of thermosetting acrylic resin on its surface was coated with the photosensitive resin composition of each Example and Comparative Example on the cured film of acrylic resin using a spin coater. The photosensitive resin composition coated on the silicon substrate was baked at 100° C. for 60 seconds to obtain a coating film with a thickness of 550 nm. The formed coating film was exposed to a KrF excimer laser (NSR-S203, manufactured by Nikon Corporation) at NA / s=0.68 / 0.75 through a mask for forming a dot pattern with a dot diameter of 0.40 μm and a dot interval of 0.30 μm. The coating film after exposure was developed by contacting it with an aqueous solution of tetramethylammonium hydroxide having a concentration of 2.38% by mass at room temperature for 60 seconds. After development, the substrate was baked at 140° C. for 5 minutes to obtain a silicon substrate (M1) on which microlenses were formed. Next, a KrF resist (TDUR-P3435, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto the silicon substrate on which the microlenses were formed using a spin coater. The KrF resist applied onto the silicon substrate was baked at 100° C. for 60 seconds to obtain a coating film with a thickness of 550 nm. The entire surface of the coating film was exposed to a KrF excimer laser (NSR-S203, manufactured by Nikon Corporation) at NA / s=0.68 / 0.75. The coating film after exposure was baked at 100° C. for 90 seconds. After baking, the resist was developed by contacting with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at room temperature for 60 seconds. After development, the substrate was baked at 150° C. for 5 minutes to obtain a silicon substrate (M2) on which microlenses were formed. The remaining film ratio was calculated based on the height T1 of the microlenses of M1 and the height T2 of the microlenses of M2 according to the following formula. Remaining film rate (%)=T2 / T1×100 Based on the calculated film remaining rate, the chemical resistance was evaluated according to the following criteria. A: The remaining film rate of the lens height was 90% or more. B: The remaining film rate of the lens height was 80% or more and less than 90%. C: The remaining film rate in terms of the lens height was less than 80%.

[0214] [Table 1]

[0215] Examples 1 to 8 show that in a photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B), and a crosslinking agent (C), by using a polyhydroxystyrene resin (A) in which some of the phenolic hydroxyl groups are protected with acetal-type protecting groups, and a crosslinking agent (C) which is a multifunctional epoxy compound having two or more epoxy groups in the molecule, a photosensitive resin composition capable of forming a microlens having excellent photolithography properties and excellent chemical resistance can be obtained.

Claims

1. A photosensitive resin composition comprising: a polyhydroxystyrene resin (A); a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation; and a crosslinking agent (C), In the polyhydrostyrene resin (A), a part of the phenolic hydroxyl groups is protected by an acetal-type protecting group, The crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups. Photosensitive resin composition.

2. The photosensitive resin composition according to claim 1 , further comprising a thermal acid generator (D).

3. 3. The photosensitive resin composition according to claim 1, wherein the photoacid generator (B) is a photoacid generator (Ba) that generates an acid in response to actinic rays or radiation having a wavelength of 200 nm or more and 300 nm or less.

4. 3. The photosensitive resin composition according to claim 1, wherein the photoacid generator (B) comprises a diazomethane-type photoacid generator (B1) and / or an onium salt-type photoacid generator (B2).

5. The photosensitive resin composition according to claim 1 or 2, comprising 1.0 part by mass or more and 20 parts by mass or less of the crosslinking agent (C) relative to 100 parts by mass of the polyhydroxystyrene resin (A).

6. A cured product of the photosensitive resin composition according to claim 1 or 2.

7. A method for manufacturing an optical element comprising a plurality of microlenses including n types of microlenses on a substrate, the method comprising the steps of: The n is an integer of 2 or more, The manufacturing method includes forming a resin film on the substrate; forming a mask on the resin film, the mask having a shape corresponding to the shape of the plurality of microlenses; and forming the plurality of microlenses to which a shape of the mask is transferred by etching the resin film together with the mask; The mask comprises the following (i) to (iii): (i) applying an m-th photosensitive resin composition onto the resin film to form an m-th coating film; (ii) exposing and developing the m-th coating film to form an m-th dot at a position on the substrate corresponding to a position where an m-th microlens is to be formed; (iii) heating the m-th dot to deform the m-th dot into a shape corresponding to the shape of the m-th microlens; The above operation is repeated n times to form the The m is an integer of 1 or more and n or less, The first to nth photosensitive resin compositions used in forming the mask may be the same or different, At least one of the first to nth photosensitive resin compositions is the photosensitive resin composition according to claim 1 or 2, A production method, wherein when the coating film is formed using the photosensitive resin composition according to claim 1 or 2, the coating film is not heated after exposure and before development.

8. The method for producing an optical element according to claim 7 , wherein n is 2.

9. The method for producing an optical element according to claim 7 , wherein the photosensitive resin composition that is first applied onto the resin film in forming the mask is the photosensitive resin composition.

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