Photosensitive resin composition

Abstract

The invention relates to a photosensitive resin composition. The present invention addresses the problem of providing: a photosensitive resin composition which has excellent lithography characteristics and is capable of forming a resin film having excellent 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] A photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid by irradiation with activated light or radiation, and a cross-linking agent (C), a polyhydroxystyrene resin (A) in which a part of phenolic hydroxyl groups are protected by an acetal-type protecting group, and a polyfunctional epoxy compound (C1) having two or more epoxy groups are used.

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 manufacturing an optical element using the aforementioned photosensitive resin composition. Background Art

[0002] Conventionally, solid-state imaging devices have been used in cameras, video cameras, and the like. In such solid-state imaging devices, CCD (charge-coupled device) image sensors and CMOS (complementary metal-oxide semiconductor) image sensors have been used. In the image sensor, fine condenser lenses (hereinafter referred to as microlenses) are provided for the purpose of increasing the light collection rate.

[0003] As a method for forming the microlenses, a method called the heat flow method has been widely adopted industrially.

[0004] In the heat flow method, first, a photoresist film is formed on the upper part of a CCD element or the like. The photoresist film is a film composed of a photosensitive resin composition or the like. Then, by exposing and developing the photoresist film, a dot pattern formed of resin is formed on the element. The dot pattern includes a plurality of dots located at the positions where the microlenses are to be formed. Each dot constituting the dot pattern has a substantially cylindrical shape or a substantially frustoconical shape. By heating the dot pattern at a temperature above the glass transition temperature of the resin material constituting the dots, the resin material constituting the dots flows, and due to surface tension, the shape of each dot changes to a hemispherical lens shape. The microlens pattern is formed as described above (for example, see Patent Document 1).

[0005] In addition, as one of the methods for manufacturing microlenses for CCD or CMOS image sensors, an etching method is known. In this method, first, a microlens resin layer is formed on a color filter. Then, in the same manner as the heat flow method described in Patent Document 1 above, a lens pattern is formed on the microlens resin layer using a photosensitive resin composition. The lens pattern thus formed is used as an etching mask, and the lower microlens resin layer is etched to transfer the lens pattern shape to the microlens resin layer, thereby manufacturing microlenses.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-15245 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] Depending on the use of the optical element, sometimes microlenses having different sizes, refractive indices, or shapes are formed in the optical element.

[0011] In this case, in the above-described heat flow method and etching method, in order to form a pattern of microlenses and a mask pattern having a microlens shape, a large number of operation steps are required. If such an operation is performed, dots, patterns of microlenses, mask patterns having a microlens shape, etc. are frequently exposed to chemical solutions such as organic solvents in the manufacturing process of the optical element.

[0012] In addition, in order to form microlenses having different sizes, refractive indices, or shapes in the optical element, microlenses and mask patterns having desired sizes, refractive indices, or shapes need to be formed at predetermined positions. For this reason, good lithography characteristics are required for the photosensitive resin composition.

[0013] As described above, for the photosensitive resin composition for forming microlenses, excellent lithography characteristics and the ability to form a resin film having excellent chemical resistance are required.

[0014] The present invention has been made in view of such a conventional situation, and an object thereof is to provide a photosensitive resin composition having excellent lithography characteristics and capable of forming a resin film having excellent chemical resistance, a cured product of the photosensitive resin composition, a method for manufacturing a cured product using the photosensitive resin composition, and a method for manufacturing an optical element using the photosensitive resin composition.

[0015] Means for Solving the Problem

[0016] The inventors of the present application have found that by using a polyhydroxystyrene resin (A) in which a part of phenolic hydroxyl groups is protected with an acetal-type protecting group, 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 irradiation with actinic light or radiation, and a crosslinking agent (C), the above problems can be solved, and thus the present invention has been completed. Specifically, the present invention provides the following aspects.

[0017] A first aspect of the present invention is a photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon irradiation with actinic light or radiation, and a crosslinking agent (C),

[0018] In the above polyhydroxystyrene resin (A), a part of phenolic hydroxyl groups is protected with an acetal-type protecting group,

[0019] The above crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups.

[0020] The second aspect of the present invention is a cured product of the photosensitive resin composition according to the first aspect.

[0021] The third aspect of the present invention is a method for manufacturing an optical element, wherein the optical element has a plurality of microlenses including n kinds of microlenses on a substrate,

[0022] n is an integer of 2 or more,

[0023] The manufacturing method includes the following steps:

[0024] A step of forming a resin film on the substrate;

[0025] A step of forming a mask having a shape corresponding to the shape of the plurality of microlenses on the resin film; and

[0026] A step of etching the resin film and the mask together to form a plurality of microlenses having the shape of the mask transferred thereto,

[0027] The mask is formed by repeating the following operations (i) to (iii) n times:

[0028] (i) An operation of coating the m-th photosensitive resin composition on the resin film to form the m-th coating film;

[0029] (ii) An operation of exposing and developing the m-th coating film to form the m-th dot at a position corresponding to the position where the m-th microlens is to be formed on the substrate; and

[0030] (iii) An operation of heating the m-th dot to deform the m-th dot into a shape corresponding to the shape of the m-th microlens,

[0031] m is an integer of 1 or more and n or less,

[0032] The first to n-th photosensitive resin compositions used in the formation of the mask may be the same or different,

[0033] At least one of the first to n-th photosensitive resin compositions is the photosensitive resin composition according to the first aspect,

[0034] When the coating film is formed using the photosensitive resin composition according to the first aspect, the coating film is not heated after exposure and before development.

[0035] Advantages of the Invention

[0036] According to the present invention, it is possible to provide a photosensitive resin composition having excellent lithography characteristics and capable of forming a resin film having excellent chemical resistance, a cured product of the photosensitive resin composition, and a method for manufacturing an optical element using the foregoing photosensitive resin composition. Detailed Description

[0037] "Photosensitive Resin Composition"

[0038] The photosensitive resin composition contains a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon irradiation with activated light or radiation, and a crosslinking agent (C).

[0039] In the polyhydroxystyrene resin (A), a part of the phenolic hydroxyl groups is protected with an acetal-type protecting group.

[0040] The crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups.

[0041] The photosensitive resin composition having the above-described configuration has excellent lithography characteristics. In addition, when the photosensitive resin composition having the above-described configuration is used, a resin film excellent in chemical resistance can be formed.

[0042] <Polyhydroxystyrene resin (A)>

[0043] The photosensitive resin composition contains a polyhydroxystyrene resin (A). In the polyhydroxystyrene resin (A), a part of the phenolic hydroxyl groups is protected with an acetal-type protecting group.

[0044] Such a polyhydroxystyrene resin (A) is deprotected well by the action of the acid generated by the photoacid generator (B) upon exposure, and the solubility in the developer changes. Therefore, if a photosensitive resin composition containing the above polyhydroxystyrene resin (A) is used and a patterned resin film is formed by a lithography method including development, it is easy to obtain a resin film patterned into a desired shape. As the developer, an alkaline developer is preferably used in terms of easily obtaining a resin film patterned into a desired shape.

[0045] As a preferred example of the polyhydroxystyrene resin (A), a resin having a structural unit represented by the following formula (a1) and a structural unit represented by the following formula (a2) can be cited. Hereinafter, the structural unit represented by the formula (a1) will also be referred to as "structural unit (a1)". The structural unit represented by the formula (a2) will also be referred to as "structural unit (a2)".

[0046] [Chemical formula 1]

[0047]

[0048] (In the formula (a1), R a1 is a hydrogen atom, an alkyl group, a halogen atom, or a haloalkyl group. R 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.)

[0049] [Chemical formula 2]

[0050]

[0051] (In formula (a2), R a3 is a hydrogen atom, an alkyl group, a halogen atom, or a haloalkyl group. R a4 , R a5 and R a6 are each independently a hydrogen atom or an alkyl group. R 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.)

[0052] In formula (a1) and formula (a2), R a1 and R a3 are a hydrogen atom, an alkyl group, a halogen atom, or a haloalkyl group.

[0053] As the alkyl group for R a1 and R a3 , as long as the desired effects are not impaired, there is no particular limitation on the number of carbon atoms. The number of carbon atoms of the alkyl group for R a1 and R a3 is preferably 1 or more and 5 or less. The alkyl group for R a1 and R a3 can be linear or branched. Specific examples of the alkyl group for R a1 and R a3 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, and neopentyl. Industrially, methyl is preferred.

[0054] Specific examples of the halogen atom in the halogen atom or haloalkyl group for R a1 and R a3 include fluorine atom, chlorine atom, bromine atom, and iodine atom. Among them, a fluorine atom is preferred. As the haloalkyl group, it is preferably a group obtained by substituting part or all of the hydrogen atoms in the above alkyl group having 1 or more and 5 or less carbon atoms with a halogen atom. The haloalkyl group can be linear or branched. Specific preferred examples of the haloalkyl group include fluoroalkyl groups such as trifluoromethyl, pentafluoroethyl, heptafluoropropyl, and nonafluorobutyl.

[0055] As R a1 and R a3 , a hydrogen atom and a methyl group are preferred, and a hydrogen atom is more preferred.

[0056] The number of carbon atoms of the alkyl group for R a2 and R a4 is preferably 1 or more and 5 or less. Preferred examples of the alkyl group for R a2 and R a4 are the same as those for the alkyl group for R a1 and Ra3 Similarly, preferred examples of the alkyl group are as follows.

[0057] q, s, and t are each independently an integer of 0 or more and 4 or less. Among them, q, s, and t are preferably 0 or 1, and particularly preferably 0 industrially.

[0058] In formula (a1), when q is 1, the substitution position of R a2 can be any of ortho, meta, and para positions with respect to the carbon atom bonded to the carbon atom to which R a1 is bonded on the benzene ring in formula (a1).

[0059] When q is an integer of 2 or more and 4 or less, R a2 can be bonded to any position on the benzene ring in formula (a1).

[0060] In formula (a2), when t is 1, the substitution position of R a4 can be any of ortho, meta, and para positions with respect to the carbon atom bonded to the carbon atom to which the same R a3 is bonded on the benzene ring in formula (a2).

[0061] When t is an integer of 2 or more and 4 or less, R a4 can be bonded to any position on the benzene ring in formula (a2).

[0062] 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.

[0063] 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.

[0064] When p is 1 or s is 1, the substitution position of the hydroxyl group in formula (a1) and formula (a2) can be any of ortho, meta, and para positions with respect to the carbon atom bonded to the carbon atom to which the same R a1 or R a3 is bonded on the benzene ring in formula (a1) or formula (a2). From the viewpoint of easily obtaining the monomer providing the structural unit represented by formula (a1) or formula (a2) and low cost, the para position is preferred.

[0065] When p is an integer of 2 or more and 5 or less in formula (a1), or s is an integer of 2 or more and 4 or less in formula (a2), the hydroxyl group can be bonded to any position on the benzene ring in formula (a1) and formula (a2).

[0066] 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.

[0067] When r is 1, in formula (a2), -C(R a5 )(R a6 )OR a7 The substitution position of the group represented can be ortho, meta, or para with respect to the position of the carbon atom bonded to the carbon atom bonded to R a3 on the benzene ring in formula (a2).

[0068] In formula (a2), when r is an integer of 2 or more and 5 or less, -C(R a5 )(R a6 )OR a7 The group represented can be bonded to any position on the benzene ring in formula (a2).

[0069] In the acetal-type protecting group -C(R a5 )(R a6 )OR a7 represented in formula (a2), R a5 and R a6 are each independently a hydrogen atom or an alkyl group. R a7 is an alkyl group or a cycloalkyl group. At least two of R a5 , R a6 and R a7 can be bonded to each other to form a ring.

[0070] As R a5 or R a6 , the number of carbon atoms of the alkyl group is preferably 1 or more and 6 or less. The alkyl group as R a5 or R a6 can be linear or branched.

[0071] As R a7 , the number of carbon atoms of the alkyl group is preferably 1 or more and 10 or less. The alkyl group as R a7 can be linear or branched.

[0072] As R a7 , the number of carbon atoms of the cycloalkyl group is preferably 3 or more and 10 or less, for example.

[0073] Regarding specific examples of the alkyl group as Ra 5 , R a6 or R a7 , examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, and neopentyl.

[0074] Regarding specific examples of the cycloalkyl group as R a7 , examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, and cyclooctyl.

[0075] As the -C(R a5 )(R a6 )OR a7 represented in formula (a2), specific examples of the acetal-type protecting group include 1-methoxyethyl, 1-ethoxyethyl, 1-n-propoxyethyl, 1-isopropoxyethyl, 1-n-butoxyethyl, 1-isobutoxyethyl, 1-tert-butoxyethyl, 1-cyclohexyloxyethyl, 1-methoxypropyl, 1-ethoxypropyl, 1-methoxy-1-methylethyl, and 1-ethoxy-1-methylethyl, etc.

[0076] The polyhydroxystyrene resin (A) may contain one or more than two kinds of structural units (a1). The polyhydroxystyrene resin (A) may contain one or more than two kinds of structural units (a2).

[0077] Relative to the total number of moles of all the structural units constituting the polyhydroxystyrene resin (A), the total ratio of the structural unit (a1) and 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%.

[0078] Relative to the total number of moles of the structural unit (a1) and the structural unit (a2), the proportion of 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 from hydroxystyrene. If the protection rate is within the above range, a photosensitive resin composition with particularly good patterning properties can be easily obtained.

[0079] Relative to the total number of moles of all the structural units constituting the polyhydroxystyrene resin (A), the proportion of 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.

[0080] The polyhydroxystyrene resin (A) may contain other structural units (a3) in addition to the structural unit (a1) and the structural unit (a2).

[0081] As other monomers that provide other structural units (a3), examples include (meth)acrylates, (meth)acrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, and maleimides, etc. These compounds can be used alone or in combination of two or more.

[0082] Examples of the (meth)acrylate include linear or branched (meth)acrylate alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, pentyl (meth)acrylate, and tert-octyl (meth)acrylate; chloroethyl (meth)acrylate, 2,2-dimethyl-3-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, benzyl (meth)acrylate, and furfuryl (meth)acrylate; glycidyl (meth)acrylate; and (meth)acrylate containing a group having an alicyclic skeleton.

[0083] In the (meth)acrylate containing a group having an alicyclic skeleton, the alicyclic group constituting the alicyclic skeleton may be a monocyclic or polycyclic group. Examples of the monocyclic alicyclic group include cyclopentyl and cyclohexyl. In addition, examples of the polycyclic alicyclic group include norbornyl, isobornyl, tricyclononyl, tricyclodecyl, and tetracyclododecyl.

[0084] Examples of the (meth)acrylamide 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.

[0085] Examples of the allyl compound 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.

[0086] Examples of the vinyl ether 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; vinyl aryl ethers such as vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, and vinyl anthryl ether; and the like.

[0087] Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl diethylacetate, 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, vinyl naphthoate, and the like.

[0088] Examples of styrenes include styrene; alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, and acetoxymethylstyrene; alkoxystyrenes such as methoxystyrene, 4-methoxy-3-methylstyrene, and dimethoxystyrene; halogenated styrenes such as chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, and 4-fluoro-3-trifluoromethylstyrene; and the like.

[0089] Examples of maleimides include N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-n-butylmaleimide, N-n-pentylmaleimide, N-n-hexylmaleimide, and other maleimides obtained by N-substitution with an alkyl group having 1 to 10 carbon atoms; N-cyclopentylmaleimide, N-cyclohexylmaleimide, N-cycloheptylmaleimide, and other maleimides obtained by N-substitution with an alicyclic group having 3 to 20 carbon atoms; N-phenylmaleimide, N-α-naphthylmaleimide, N-β-naphthylmaleimide, and other N-arylmaleimides obtained by N-substitution with an aryl group having 6 to 20 carbon atoms; N-benzylmaleimide, N-phenethylmaleimide, and other N-arylalkylmaleimides obtained by N-substitution with an arylalkyl group having 7 to 20 carbon atoms.

[0090] The weight average molecular weight (Mw) of the polyhydroxystyrene resin (A) is preferably 5,000 or more and 30,000 or less. It should be noted that in this specification, the weight average molecular weight is the weight average molecular weight in terms of polystyrene based on gel permeation chromatography (GPC).

[0091] <Photoacid generator (B)>

[0092] The photosensitive resin composition contains a photoacid generator (B) that generates an acid upon irradiation with actinic light or radiation. Due to the action of the acid generated by the photoacid generator (B) upon exposure, the polyhydroxystyrene resin (A) is deprotected and its solubility in the developer changes. Therefore, the photosensitive resin composition can be suitably applied to patterning using photolithography.

[0093] The photoacid generator (B) is not particularly limited, and the photoacid generators previously incorporated into the photosensitive resin composition can be used without particular limitation. As the photoacid generator (B), a photoacid generator (B-a) that generates an acid upon irradiation with actinic light or radiation having an induction wavelength of 200 nm or more and 300 nm or less is preferred.

[0094] 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; nitrobenzyl sulfonate type photoacid generators; iminosulfonate type photoacid generators; disulfone type photoacid generators, and the like.

[0095] Among them, from the viewpoint of easily obtaining a photosensitive resin composition having excellent lithography characteristics, a diazomethane type photoacid generator or an onium salt type photoacid generator is preferred. Hereinafter, the diazomethane type photoacid generator will also be referred to as the diazomethane type photoacid generator (B1). The onium salt type photoacid generator will also be referred to as the onium salt type photoacid generator (B2).

[0096] Hereinafter, the diazomethane type photoacid generator (B1) and the onium salt type photoacid generator (B2) will be described.

[0097] 〔Diazomethane type photoacid generator (B1)〕

[0098] Hereinafter, the diazomethane type photoacid generator (B1) will be described.

[0099] Examples of the diazomethane type photoacid generator (B1) include bis(sulfonyl)diazomethane compounds such as bis(alkylsulfonyl)diazomethane, bis(cycloalkylsulfonyl)diazomethane, and bis(arylsulfonyl)diazomethane.

[0100] Specific examples of the bis(sulfonyl)diazomethane compound include bis(isopropylsulfonyl)diazomethane, bis(tert-butylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane, and the like.

[0101] Poly(bis-sulfonyl)diazomethane can also be used as the diazomethane type photoacid generator (B2). Examples of poly(bis-sulfonyl)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, 1,10-bis(cyclohexylsulfonyldiazomethylsulfonyl)decane, and the like.

[0102] [Onium salt type photoacid generator (B2)]

[0103] Preferred examples of the onium salt type photoacid generator (B2) include the compound represented by the following formula (b-1) or the compound represented by the formula (b-2). Hereinafter, the compound represented by the formula (b-1) is also referred to as the "(b-1) component". The compound represented by the formula (b-2) is also referred to as the "(b-2) component".

[0104] [Chemical formula 3]

[0105]

[0106] (In formula (b-1) and formula (b-2), R 101 and R 104 ~R 105 are each independently a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. R 104 and R 105 may be bonded to each other to form a ring. R 102 is a fluoroalkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 ~V 103 are each independently a single bond, an alkylene group or a fluoroalkylene group. L 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 m-valent onium cation.)

[0107] (Anion part)

[0108] Hereinafter, the anion part constituting the (b-1) component will be described.

[0109] In formula (b-1), R 101 is 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.

[0110] R 101 In the case of a cyclic group that may have a substituent, as the cyclic group, a cyclic hydrocarbon group is preferred. 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.

[0111] As R 101 The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 or more and 30 or less, more preferably 6 or more and 20 or less, still more preferably 6 or more and 15 or less, and particularly preferably 6 or more and 10 or less. Among them, when the aromatic hydrocarbon group has a substituent, the above-mentioned number of carbon atoms does not include the number of carbon atoms of the substituent.

[0112] Regarding the aromatic hydrocarbon group as R 101 Specific examples of the aromatic hydrocarbon ring contained in the aromatic hydrocarbon group as R include a benzene ring, a fluorene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a biphenyl ring.

[0113] As R 101 The cyclic group as R may include an aromatic heterocycle in which a part of the carbon atoms constituting the above-mentioned aromatic hydrocarbon ring is replaced by a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, etc.

[0114] Regarding the aromatic hydrocarbon group as R 101 Specific examples of the aromatic hydrocarbon group as R include a phenyl group, a naphthalen-1-yl group, a naphthalen-2-yl group, a 4-phenylphenyl group, a 3-phenylphenyl group, and a 2-phenylphenyl group.

[0115] Regarding the alicyclic hydrocarbon group as R 101 Examples of the alicyclic hydrocarbon group in the structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an alicyclic hydrocarbon ring), a group obtained by bonding an alicyclic hydrocarbon group to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group.

[0116] Examples of the alicyclic hydrocarbon group in the structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an alicyclic hydrocarbon ring), a group obtained by bonding an alicyclic hydrocarbon group to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group.

[0117] The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 or more and 20 or less, more preferably 3 or more and 12 or less.

[0118] The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. The number of carbon atoms of the monocycloalkane is preferably 3 or more and 6 or less. Specific examples of the monocycloalkane include cyclopentane and cyclohexane.

[0119] As the polycyclic alicyclic hydrocarbon group, it is preferably a group obtained by removing one or more hydrogen atoms from a polycyclic alkane. The number of carbon atoms of the polycyclic alkane is preferably 7 or more and 30 or less. Specific examples of the polycyclic alkane include polycyclic alkanes having a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycyclic alkanes having a fused ring system such as a cyclic group having a steroid skeleton.

[0120] Regarding the alicyclic hydrocarbon group as R 101 , it is preferably a group obtained by removing one or more hydrogen atoms from a monocyclic alkane or a polycyclic alkane, more preferably a group obtained by removing one hydrogen atom from a polycyclic alkane, particularly preferably an adamantyl group and a norbornyl group, and most preferably an adamantyl group.

[0121] The number of carbon atoms of the straight-chain aliphatic hydrocarbon group that can be bonded to the alicyclic hydrocarbon group is preferably 1 or more and 10 or less, more preferably 1 or more and 6 or less, further preferably 1 or more and 4 or less, and most preferably 1 or more and 3 or less. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred. Preferred specific examples of the straight-chain alkylene group include methylene, ethane-1,2-diyl (ethylene), propane-1,3-diyl (1,3-propylene), butane-1,4-diyl (1,4-butylene), and pentane-1,5-diyl (1,5-pentylene).

[0122] The number of carbon atoms of the branched-chain aliphatic hydrocarbon group that can 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, further preferably 3 or 4, and most preferably 3. As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferred. Specifically, it includes -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 - and other alkylmethylenes; -CH(CH 3 )CH 2 (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 - and other alkylethylenes such as -CH(CH 3 )CH 2 CH 2 -; -CH 2 CH(CH 3 )CH 2 - and other alkyl-1,3-propylenes such as -CH(CH 3 )CH 2 CH 2 CH 2 -; -CH 2 CH(CH 3 )CH 2 CH 2 - and other alkyl-1,4-butylenes and other alkylenealkylenes. As the alkyl group in the alkylenealkylenes, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0123] Regarding the cyclic group as R 101 , examples thereof include a cyclic group containing a lactone, a cyclic group containing -SO 2 - represented by the following formulas (b-r2-1) to (b-r2-4), and other heterocyclic groups.

[0124] The so-called "cyclic group containing -SO 2 -" means a cyclic group containing a ring having a -SO 2 - bond in its ring skeleton. The cyclic group containing -SO 2 - may be a monocyclic group or a polycyclic group. When the cyclic group containing -SO 2 - is formed only by a ring containing -SO 2 -, the cyclic group containing -SO 2 - is a monocyclic group. When the cyclic group containing -SO 2 - is formed by two or more -SO 2 - rings, or when it has a -SO 2 - ring and also has a ring having a structure other than the -SO 2 - ring structure, the cyclic group containing -SO 2 - is a polycyclic group.

[0125] As the cyclic group containing -SO 2 -, particularly preferred is a cyclic group containing -O-SO 2-Ring group of the key. Such a ring group contains a sultone ring.

[0126] As a ring group containing -SO 2 -, more specifically, the groups represented by the following formulas (b-r2-1) to (b-r2-4) can be cited.

[0127] [Chemical formula 4]

[0128]

[0129] (In the formulas (b-r2-1) to (b-r2-4), R b21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group, a ring group containing a lactone, a ring group containing a carbonate or a ring group containing -SO 2 -; B" is an alkylene group having 1 or more and 5 or less carbon atoms which may contain an oxygen atom, an alkylene group having 1 or more and 5 or less carbon atoms which may contain a sulfur atom, an oxygen atom or a sulfur atom; n' is 0, 1 or 2.)

[0130] In the formulas (b-r2-1) to (b-r2-4), regarding R b21 as the alkyl group, it is preferably an alkyl group having 1 or more and 6 or less carbon atoms. This alkyl group may be linear or branched. As specific examples of this alkyl group, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl and n-hexyl etc. can be cited. Among them, methyl and ethyl are preferred, and methyl is particularly preferred.

[0131] Regarding R b21 as the alkoxy group, it is preferably an alkoxy group having 1 or more and 6 or less carbon atoms. This alkoxy group may be linear or branched. As specific examples of this alkoxy group, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, isopentyloxy, neopentyloxy and n-hexyloxy etc. can be cited. Among them, methoxy and ethoxy are preferred, and methoxy is particularly preferred.

[0132] Regarding R b21 as the halogen atom, fluorine atom, chlorine atom, bromine atom and iodine atom can be cited. Among them, fluorine atom is preferred.

[0133] Regarding R b21 as the haloalkyl group, the group in which a part or all of the hydrogen atoms of the alkyl group as R b21 are substituted by the aforementioned halogen atoms can be cited. As this haloalkyl group, fluoroalkyl group is preferred, and perfluoroalkyl group is particularly preferred.

[0134] As R b21 in -COOR” and -OC(=O)R”, R” is each independently a hydrogen atom, an alkyl group, an alicyclic hydrocarbon group, a cyclic group containing a lactone, a cyclic group containing a carbonate, or a cyclic group containing -SO 2 -. The alicyclic hydrocarbon group as R” may be substituted with a fluorine atom or a fluoroalkyl group.

[0135] In formulas (b-r2-1) to (b-r2-4), the alkylene group having 1 to 5 carbon atoms as B” may be linear or branched. Specific examples of the alkylene group include a methylene group, an ethylene group, a n-propylene group, an isopropyl group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which -O- or -S- is interposed at the terminal or between carbon atoms of the alkylene group. For example, -O-CH 2 -, -CH 2 -O-CH 2 -, -S-CH 2 -, -CH 2 -S-CH 2 -, etc. As B”, an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is most preferred.

[0136] Hereinafter, specific examples of the groups represented by formulas (b-r2-1) to (b-r2-4) are shown. “Ac” in the formula represents an acetyl group.

[0137] [Chemical formula 5]

[0138]

[0139] [Chemical formula 6]

[0140]

[0141] [Chemical formula 7]

[0142]

[0143] In formula (b-1), examples of the substituents that the cyclic group as R 101 may have include an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

[0144] Regarding the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, a n-butyl group, and a tert-butyl group are more preferred.

[0145] Regarding the alkoxy group as a substituent, an alkoxy group having 1 or more and 5 or less carbon atoms is preferred, a methoxy group, an ethoxy group, a n-propoxy group, an isopropyloxy group, a n-butoxy group, or a tert-butoxy group is more preferred, and a methoxy group or an ethoxy group is most preferred.

[0146] Regarding the halogen atom as a substituent, a fluorine atom is preferred.

[0147] Regarding the haloalkyl group as a substituent, a haloalkyl group having 1 or more and 5 or less carbon atoms is preferred, and a halomethyl group, a haloethyl group, a halopropyl group, a halon-butyl group, or a halotert-butyl group is more preferred. The haloalkyl group may be a group in which a part of the hydrogen atoms in the alkyl group are substituted with halogen atoms, or a group in which all of the hydrogen atoms in the alkyl group are substituted with halogen atoms.

[0148] The carbonyl group as a substituent is a group that substitutes the methylene group (-CH 2 -) included in the cyclic group.

[0149] As R 101 The chain-like alkyl group may be linear or branched.

[0150] The number of carbon atoms of the linear alkyl group is preferably 1 or more and 20 or less, more preferably 1 or more and 15 or less, and most preferably 1 or more and 10 or less.

[0151] As specific preferred examples of the linear alkyl group, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, and n-eicosyl can be mentioned.

[0152] The number of carbon atoms of the branched alkyl group is preferably 3 or more and 20 or less, more preferably 3 or more and 15 or less, and most preferably 3 or more and 10 or less. As specific preferred examples of the branched alkyl group, 1-methylethyl (isopropyl), 1-methylpropyl (sec-butyl), 2-methylpropyl (isobutyl), 1-methylbutyl (sec-pentyl), 2-methylbutyl, 3-methylbutyl (isobutyl), 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl can be mentioned.

[0153] The chain-like alkenyl group which may have a substituent:

[0154] As R 101The chain alkenyl group can be linear or branched. The number of carbon atoms in the chain alkenyl group is preferably 2 or more and 10 or less, more preferably 2 or more and 5 or less, still more preferably 2 or more and 4 or less, and particularly preferably 3. Specific preferred examples of the linear alkenyl group include, for example, vinyl, 1-propenyl, 2-propenyl (allyl), and butenyl. Specific preferred examples of the branched alkenyl group include, for example, 1-methylethenyl, 1-methylpropenyl, and 2-methylpropenyl.

[0155] Among the above-mentioned alkenyl groups, a linear alkenyl group is preferred, vinyl and propenyl are more preferred, and vinyl is particularly preferred.

[0156] Regarding the substituents that the chain alkyl group or chain alkenyl group as R 101 may have, for example, alkoxy groups, halogen atoms, haloalkyl groups, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above-mentioned cyclic groups as R 101 can be cited.

[0157] As R 101 , a cyclic group that may have substituents is preferred, and a cyclic hydrocarbon group that may have substituents is more preferred. More specifically, phenyl, naphthyl, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane, a cyclic group containing a lactone, and a cyclic group represented by the formula (b-r2-1) to (b-r2-4) containing -SO 2 - etc. are preferred.

[0158] In the formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom.

[0159] When Y 101 is a divalent linking group containing an oxygen atom, this Y 101 may also contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc.

[0160] Examples of the divalent linking group containing an oxygen atom include, for example, an oxygen atom (-O-), -C(=O)-, -O-C(=O)-, -C(=O)-NH-, a carbonyl group, -O-C(=O)-O- and other linking groups containing an oxygen atom; combinations of such linking groups containing an oxygen atom with an alkylene group, etc. A sulfonyl group (-SO 2 -) may be further linked to this combination. Examples of the divalent linking group containing an oxygen atom include, for example, the linking groups represented by the following formula (b-y-1) to (b-y-7).

[0161] [Chemical formula 8]

[0162]

[0163] (In formulas (b-y-1) to (b-y-7), V’ 101 is a single bond or an alkylene group having 1 or more and 5 or less carbon atoms, and V’ 102 is a divalent saturated hydrocarbon group having 1 or more and 30 or less carbon atoms.)

[0164] As V’ 102 the divalent saturated hydrocarbon group can be a linear saturated hydrocarbon group, a cyclic saturated hydrocarbon group, or a combination of a linear saturated hydrocarbon group and a cyclic saturated hydrocarbon group. As V’ 102 the divalent saturated hydrocarbon group is preferably an alkylene group. The number of carbon atoms of the alkylene group is preferably 1 or more and 30 or less, more preferably 1 or more and 10 or less, and still more preferably 1 or more and 5 or less.

[0165] As V’ 101 and V’ 102 the alkylene group can be linear or branched, and is preferably linear.

[0166] Regarding specific examples of the alkylene group as V’ 101 and V’ 102 , examples include methylene; -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 )- and -C(CH 2 CH 3 ) 2 - and other alkylmethylenes; ethylene (-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 alkylethylenes; 1,3-propylene (-CH 2 CH 2 CH 2 -); -CH(CH 3 )CH2 CH 2 - and -CH 2 CH(CH 3 )CH 2 - and other alkyl-1,3-propylene groups; 1,4-butylene (-CH 2 CH 2 CH 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-1,4-butylene groups; 1,5-pentylene (-CH 2 CH 2 CH 2 CH 2 CH 2 -), etc.

[0167] In addition, as the alkylene group of V' 101 or V' 102 a part of the methylene groups can be replaced by a divalent aliphatic cyclic group having 5 or more and 10 or less carbon atoms. This aliphatic cyclic group can be a monocyclic group or a polycyclic group.

[0168] Regarding the aliphatic hydrocarbon group that is a monocyclic group, it is preferably a group obtained by removing 2 hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 or more and 6 or less carbon atoms. Examples of the group obtained by removing 2 hydrogen atoms from a monocycloalkane include cyclopentylene and cyclohexylene. Among them, cyclohexylene is more preferred.

[0169] Regarding the aliphatic hydrocarbon group that is a polycyclic group, it is preferably a group obtained by removing 2 hydrogen atoms from a polycycloalkane. The polycycloalkane preferably has 7 or more and 12 or less carbon atoms. Examples of the group obtained by removing 2 hydrogen atoms from a polycycloalkane include adamantanediyl, norbornanediyl, isobornanediyl, tricyclodecanediyl, and tetracyclododecanediyl. Among them, adamantane-1,5-diyl and adamantane-2,6-diyl are more preferred.

[0170] This aliphatic cyclic group may have a substituent. Examples of this substituent include -R P1 , -R P2 -O-R P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1, -R P2 , -O-CO-R P1 , -R P2

[0171] , -OH, -R P2 , -CN and -R P2 , -COOH, etc.

[0172] R P1 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. R P2 is a single bond, a divalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms.

[0173] R P1 and R P2 may also be a group in which a part or all of the hydrogen atoms of the above-mentioned chain-like saturated hydrocarbon group, cyclic saturated hydrocarbon group, and aromatic hydrocarbon group are substituted by fluorine atoms.

[0174] The above-mentioned cyclic hydrocarbon group may have one or more of the above-mentioned substituents of a single kind, or may have one or more of each of the above-mentioned substituents of multiple kinds.

[0175] As the monovalent alkyl group having 1 to 10 carbon atoms, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, etc. can be cited.

[0176] As the monovalent cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, for example, cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl; bicyclo[2.2.2]octyl, tricyclo[5.2.1.0 2,6 decyl, tricyclo[3.3.1.1 3,7 decyl, tetracyclo[6.2.1.1 3,6 .0 2,7 dodecyl, adamantyl and other polycyclic saturated hydrocarbon groups.

[0177] As the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, for example, phenyl, biphenyl, fluorenyl, naphthyl, anthryl, and phenanthryl can be cited.

[0178] As Y 101 , it is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably the linking group represented by each of the above formulas (b-y-1) to (b-y-7).

[0179] In formula (b-1), V 101is a single bond, an alkylene group or a fluoroalkylene group. As V 101 The number of carbon atoms of the alkylene group and the fluoroalkylene group as V 101 is preferably 1 or more and 4 or less. Regarding the fluoroalkylene group as V 101 a group in which a part or all of the hydrogen atoms of the alkylene group as V 101 are substituted by fluorine atoms can be mentioned. Among them, as V

[0180] In formula (b-1), R 102 is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. As R 102 is preferably a fluorine atom and a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

[0181] Y 101 When Y is a single bond, specific examples of the anionic part represented by formula (b-1) include fluoroalkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion. When Y 101 is a divalent linking group containing an oxygen atom, specific examples of the anionic part represented by formula (b-1) include the anions represented by the following formulas (ba-1) to (ba-3).

[0182] [Chemical formula 9]

[0183]

[0184] (In formulas (ba-1) to (ba-3), R” 101 is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group or an alkyl group which may have a substituent. R” 102 is an aliphatic cyclic group which may have a substituent, a cyclic group containing a lactone or a cyclic group represented by formulas (b-r2-1) to (b-r2-4) containing -SO 2 -. R” 103 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. V” 101 is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluoroalkylene group having 1 to 4 carbon atoms. R 102 is a fluorine atom or a fluoroalkyl group having 1 to 5 carbon atoms. v” are each independently an integer of 0 or more and 3 or less, q” are each independently an integer of 0 or more and 20 or less, and n” is 0 or 1.)

[0185] As R” 101 、R” 102 and R” 103The aliphatic cyclic group which may have a substituent is preferably a group exemplified as the alicyclic hydrocarbon group for R in formula (b-1). 101 As the substituent, the same groups as those which can substitute the alicyclic hydrocarbon group for R in formula (b-1) can be mentioned. 101

[0186] As R'' 103 The aromatic cyclic group which may have a substituent is preferably a group exemplified for R in formula (b-1) and regarding the aromatic hydrocarbon group as the cyclic hydrocarbon group. As the substituent, the same groups as those which can substitute the aromatic hydrocarbon group for R in formula (b-1) can be mentioned. 101 101

[0187] As R'' 101 The linear alkyl group which may have a substituent is preferably a group exemplified as the linear alkyl group for R in formula (b-1). 101

[0188] As R'' 103 The linear alkenyl group which may have a substituent is preferably a group exemplified as the linear alkenyl group for R in formula (b-1). 101

[0189] Hereinafter, the anionic part constituting the component (b-2) will be described.

[0190] In formula (b-2), R 104 and R 105 are each independently a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. As examples of these groups, the same groups as R in formula (b-1) can be mentioned respectively. R 101 and R 104 and R 105 may bond to each other to form a ring.

[0191] As R 104 and R 105 are preferably an alkyl group which may have a substituent, more preferably an alkyl group or a fluoroalkyl group. The alkyl group and the fluoroalkyl group may be linear or branched.

[0192] The number of carbon atoms of the alkyl group is preferably 1 or more and 10 or less, more preferably 1 or more and 7 or less, and further preferably 1 or more and 3 or less. From the viewpoint that the onium salt type acid generator (B2) is easily soluble in a solvent and the like, the smaller the number of carbon atoms of the alkyl group as R 104 and R 105 is, the more preferable. In addition, for R 104 and R 105 ​​​​​For a fluoroalkyl group, from the aspect of the stronger acid strength and the aspect of higher transparency to high-energy light and electron beams with a wavelength of 250 nm or less, the larger the number of hydrogen atoms substituted by fluorine atoms, the more preferred. The proportion of fluorine atoms in the fluoroalkyl group, that is, 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 by fluorine atoms.

[0193] In formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group or a fluoroalkylene group, and examples of each may include the same bond or group as V 101 in formula (b-1).

[0194] In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0195] (Cation part)

[0196] In formula (b-1), formula (b-2), and formula (b-3), M' m+ represents an m-valent onium cation. As the onium cation, a sulfonium cation is preferred.

[0197] m is an integer of 1 or more.

[0198] As M' m+ represents an organic cation, there is no particular limitation, and an organic cation known as the cation part constituting a conventionally known onium salt type acid generator can be appropriately used. As the cation part, a sulfonium cation is preferred.

[0199] As a specific example, for example, a sulfonium cation represented by the following formula (bc-1) or (bc-2) can be cited.

[0200] [Chemical formula 10]

[0201]

[0202] (In formula (bc-1) and (bc-2), R bc1 ~R bc8 each independently represent an aryl group, an alkyl group, a cycloalkyl group or an alkenyl group which may have a substituent. R bc1 ~R bc5 may be bonded to each other to form a ring together with the sulfur atom in the formula. R bc6 ~R bc7 each independently represent a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms. 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 a group containing -SO2 - cyclic group. L bc1 represents -C(=O)- or -C(=O)-O-. )

[0203] In formulas (bc-1) and (bc-2), regarding R bc1 ~R bc5 aryl, unsubstituted aryl having 6 or more and 20 or less carbon atoms can be exemplified. As the unsubstituted aryl, phenyl and naphthyl are preferred.

[0204] As R bc1 ~R bc5 alkyl preferably has 1 or more and 30 or less carbon atoms.

[0205] As R bc1 ~R bc5 cycloalkyl preferably has 3 or more and 30 or less carbon atoms.

[0206] As R bc1 ~R bc5 alkenyl preferably has 2 or more and 10 or less carbon atoms.

[0207] As R bc1 ~R bc5 and R bc8 substituents that may be present, for example, include alkyl, halogen atom, haloalkyl, carbonyl, cyano, amino, aryl, groups represented by the following formulas (bc-r-1) to (bc-r-7), etc.

[0208] [Chemical formula 11]

[0209]

[0210] (In formulas (bc-r-1) to (bc-r-7), R’ b11 are each independently a hydrogen atom, a cyclic group that may have a substituent, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent. )

[0211] Regarding the cyclic group as R’ b11 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.

[0212] As the aromatic hydrocarbon group of R’ b11 preferably has 3 or more and 30 or less carbon atoms, more preferably 5 or more and 30 or less carbon atoms, further preferably 5 or more and 20 or less carbon atoms, particularly preferably 6 or more and 15 or less carbon atoms, and most preferably 6 or more and 10 or less carbon atoms. However, the carbon atom count does not include the carbon atoms of the substituents.

[0213] About being R' b11 Specific examples of the aromatic hydrocarbon ring contained in the aromatic hydrocarbon group include a benzene ring, a fluorene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring and a biphenyl ring.

[0214] As R' b11 The cyclic group may include an aromatic heterocycle in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring is replaced by a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0215] About being R' b11 Specific examples of the aromatic hydrocarbon group include phenyl, naphth-1-yl, naphth-2-yl, 4-phenylphenyl, 3-phenylphenyl and 2-phenylphenyl.

[0216] As R' b11 The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.

[0217] 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. Preferred specific examples of the cycloalkyl group include cyclopentyl and cyclohexyl. As a polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane is preferred. The number of carbon atoms of the polycyclic alkane is preferably 7 or more and 30 or less. Preferred specific examples of polycyclic alkanes include polycyclic alkanes with polycyclic skeletons of bridged ring systems such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane; polycyclic alkanes with polycyclic skeletons of fused ring systems such as cyclic groups with steroidal skeletons.

[0218] Among them, regarding R' b11 The alicyclic hydrocarbon group is preferably adamantyl and norbornyl, and more preferably adamantyl.

[0219] As R' b11 The cyclic hydrocarbon group may be a heterocyclic ring containing a heteroatom. Specifically, there can be mentioned a lactone-containing cyclic group, a -SO 2 -cyclic groups, other heterocyclic groups.

[0220] Regarding R' in formulas (bc-r-1) to (bc-r-7) b11 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

[0221] Regarding the alkyl group as a substituent, an alkyl group having 1 or more and 5 or less carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, a n-butyl group, and a tert-butyl group are more preferred.

[0222] Regarding the alkoxy group as a substituent, an alkoxy group having 1 or more and 5 or less carbon atoms is preferred, a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are further preferred.

[0223] Regarding the halogen atom as a substituent, a fluorine atom is preferred.

[0224] Regarding the haloalkyl group as a substituent, examples thereof include a group in which part or all of the hydrogen atoms of an alkyl group having 1 or more and 5 or less carbon atoms, such as a methyl group, an ethyl group, a propyl group, a n-butyl group, and a tert-butyl group, are substituted with halogen atoms.

[0225] The carbonyl group as a substituent is a group that substitutes the methylene group (-CH 2 -) constituting the cyclic hydrocarbon group.

[0226] As R’ b11 the alkyl group can be either linear or branched.

[0227] The number of carbon atoms of the linear alkyl group is preferably 1 or more and 20 or less, more preferably 1 or more and 15 or less, and further preferably 1 or more and 10 or less.

[0228] The number of carbon atoms of the branched alkyl group is preferably 3 or more and 20 or less, more preferably 3 or more and 15 or less, and further preferably 3 or more and 10 or less.

[0229] Specific examples of the branched alkyl group 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.

[0230] As R’ b11 the alkenyl group can be either linear or branched.

[0231] The number of carbon atoms of the linear alkenyl group is preferably 2 or more and 10 or less, more preferably 2 or more and 5 or less, further preferably 2 or more and 4 or less, and particularly preferably 3.

[0232] 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.

[0233] Specific examples of the branched alkenyl group include a 1-methylethenyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.

[0234] As the alkenyl group, a linear alkenyl group is preferred, an ethenyl group and a propenyl group are more preferred, and an ethenyl group is particularly preferred.

[0235] Regarding the substituents that the alkyl group and alkenyl group as R’ b11 may have, for example, alkoxy groups, halogen atoms, haloalkyl groups, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the cyclic groups as R’ b11 described above can be cited.

[0236] Among them, as R’ b11 , a cyclic group that may have substituents is preferred, and a cyclic hydrocarbon group that may have substituents is more preferred. More specifically, for example, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycyclic alkane, a cyclic group containing a lactone, a cyclic group represented by formulas (b-r2-1) to (b-r2-4) and containing -SO 2 - etc. can be cited.

[0237] When two of R bc1 to R bc3 in formula (bc-1) or (bc-2) are bonded to each other to form a ring together with the sulfur atom in the formula, they can be bonded through heteroatoms such as sulfur atoms, oxygen atoms, nitrogen atoms, carbonyl groups, -SO-, -SO 2 -, -SO 3 -, -COO-, -CONH-, or -N(RN)- (where RN is an alkyl group having 1 to 5 carbon atoms) and other functional groups. As the formed ring, a ring containing the sulfur atom in the formula in its ring skeleton preferably has 3 to 10 members, particularly preferably 5 to 7 members. 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 tetrahydropyranium ring.

[0238] R bc6 to R bc7 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R bc6 to R bc7 are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. When both R bc6 and R bc7 are alkyl groups, R bc6 and R bc7 can be bonded to each other to form a ring.

[0239] R bc8 is an aryl group that may have substituents, an alkyl group that may have substituents, an alkenyl group that may have substituents, or a cyclic group containing -SO 2 - that may have substituents.

[0240] Rbc8 When it is an aryl group, as the aryl group, an unsubstituted aryl group having 6 or more and 20 or less carbon atoms is preferred, and a phenyl group, a naphthalene-1-yl group, and a naphthalene-2-yl group are more preferred.

[0241] R bc8 When it is an alkyl group, the alkyl group may be a linear or cyclic alkyl group. The number of carbon atoms of the alkyl group is preferably 1 or more and 30 or less.

[0242] R bc8 When it is an alkenyl group, the number of carbon atoms of the alkenyl group is preferably 2 or more and 10 or less.

[0243] As R bc8 The cyclic group which may have a substituent and contains -SO 2 - is preferably a "polycyclic group containing -SO 2 -".

[0244] The following shows preferred cations represented by formula (bc-1).

[0245] [Chemical formula 12]

[0246]

[0247] [Chemical formula 13]

[0248]

[0249] [Chemical formula 14]

[0250]

[0251] (In formulas (bc-1-35) to (bc-1-37), g1, g2, and g3 represent the repetition numbers of the groups in parentheses, g1 is an integer of 1 or more and 5 or less, 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.) [Chemical formula 15]

[0252]

[0253] [Chemical formula 16]

[0254]

[0255] [Chemical formula 17]

[0256]

[0257] [Chemical formula 18]

[0258]

[0259] (In the formula, R” b11is a hydrogen atom or a substituent, and this substituent is the same as that which R bc1 ~R bc5 and R bc8 may have. )

[0260] [Chemical formula 19]

[0261]

[0262] As preferred specific examples of the cation represented by formula (bc-2), the cations represented by the following formulas (bc-2-1) to (bc-2-6) can be cited.

[0263] [Chemical formula 20]

[0264]

[0265] As the cation moiety of the onium salt type photoacid generator (B2), it is represented by formulas (bc-1) and (bc-2). Among them, the cations represented by formulas (bc-1-1) to (bc-1-6), (bc-1-52) to (bc-1-60) are preferred.

[0266] Among the above-mentioned onium salt type photoacid generators (B2), the compound represented by the following formula (b-1-1) is preferred.

[0267] [Chemical formula 21]

[0268]

[0269] (In formula (b-1-1), R b1 ~R b3 each independently represents an aryl group which may have a substituent. Any two of R b1 ~R b3 can be bonded to each other to form a ring together with the sulfur atom in the formula. R 101 is 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. R 102 is a fluoroalkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 is a single bond or an oxygen atom. )

[0270] In formula (b-1-1), R 101 , Y 101 , V 101 and R 102 are the same as R 101 , Y 101 , V 101 and R 102 in formula (b-1).

[0271] R b1 ~R b3 Each independently is an aryl which may have a substituent. R b1 ~R b3 Any two of R b1 ~R b3 The aryl in R bc1 ~R bc3 is the same as the aryl in R of the above formula (bc-1). The substituent that the aryl may have is the same as the substituent that the aryl in R bc1 ~R bc3 of the above formula (bc-1) may have.

[0272] As the ring formed by bonding any two of R b1 ~R b3 to each other and the sulfur atom in the formula, a ring the same as the ring formed by bonding R bc1 ~R bc3 to each other and the sulfur atom in the formula of the above formula (bc-1) can be cited.

[0273] In the photosensitive resin composition, the photoacid generator (B) can be used alone as one kind, or two or more kinds can be used in combination.

[0274] Based on 100 parts by mass of the polyhydroxystyrene resin (A), 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, more preferably 1 part by mass or more and 10 parts by mass or less.

[0275] If the content of the photoacid generator (B) is within the above range, a photosensitive resin composition with particularly good lithography characteristics can be easily obtained.

[0276] <Crosslinking agent (C)>

[0277] The photosensitive resin composition contains a crosslinking agent (C). The crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups. The polyfunctional epoxy compound (C1) reacts with the phenolic hydroxyl groups of the polyhydroxystyrene resin (A) to crosslink the polyhydroxystyrene resin (A). The polyfunctional epoxy compound (C1) is not particularly limited as long as the desired effects are not impaired.

[0278] As the polyfunctional epoxy compound (C1), for example, bifunctional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD type epoxy resin, naphthalene type epoxy resin and biphenyl type epoxy resin can be cited; glycidyl ester type epoxy resins such as dimer acid glycidyl ester and triglycidyl ester; glycidyl amine type epoxy resins such as tetraglycidyl aminodiphenylmethane, triglycidyl - p - aminophenol, tetraglycidyl metaxylylenediamine and tetraglycidyl bis(aminomethyl)cyclohexane; heterocyclic epoxy resins such as isocyanuric acid triglycidyl ester; phloroglucinol triglycidyl ether, trihydroxybiphenyl triglycidyl ether, trihydroxyphenylmethane triglycidyl ether, glycerol triglycidyl ether, 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

[0279] -propanol and other trifunctional epoxy resins; pentaerythritol tetraglycidyl ether, tetrahydroxyphenylethane tetraglycidyl ether, tetraglycidyl benzophenone, bisresorcinol tetraglycidyl ether and tetraepoxypropoxybiphenyl and other tetrafunctional epoxy resins.

[0280] The amount of the crosslinking agent (C) used is not particularly limited as long as the photosensitive resin composition can be cured well. For example, relative to 100 parts by mass of the polyhydroxystyrene resin, 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 still more preferably 2 parts by mass or more and 30 parts by mass or less.

[0281] <Thermal acid generator (D)>

[0282] The photosensitive resin composition may further contain a thermal acid generator (D). When the photosensitive resin composition contains the thermal acid generator (D), when the photosensitive resin composition is heated, the crosslinking reaction between the polyhydroxystyrene resin (A) and the crosslinking agent (C) proceeds particularly well by the action of the acid generated by heat. As the thermal acid generator (D), for example, a thermal acid generator having a decomposition start temperature of 120 to 200 °C can be cited. The thermal acid generator (D) can be used alone or in combination of two or more.

[0283] The thermal acid generator (D) preferably contains a thermal acid generator formed from a cationic part and an anionic part, and the cationic part is a cation represented by the following formula (dc). By using such a thermal acid generator, the acid dissociable group is more likely to be detached from the resin (A), and thus, it becomes easier to generate phenolic hydroxyl groups or carboxyl groups. As a result, the curability of the curable resin composition is easily improved.

[0284] [Chemical Formula 22]

[0285]

[0286] (In formula (dc), R dc1 , R dc2 and R dc3 are each independently an alkyl group having 1 to 6 carbon atoms.)

[0287] In formula (dc), as preferred examples of the alkyl group as R dc1 , R dc2 and R dc3 , methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl and n-hexyl can be cited. As the alkyl group, methyl or ethyl is preferred, and methyl is more preferred. Particularly preferably, R d01 , R d02 and R d03 are all methyl.

[0288] That is, as the cation represented by formula (dc), the cation represented by the following formula (dc-1) is preferred.

[0289] [Chemical Formula 23]

[0290]

[0291] As the counter anion for the cation represented by formula (dc), for example, AsF 6 - , SbF 6 - , PF 6 - , CF 3 SO 3 - , the anion represented by the following formula (da-1) and the anion represented by the following formula (da-2), etc.

[0292] [Chemical Formula 24]

[0293]

[0294] (In formula (da-1), R da1 , R da2 , R da3 and R da4 are each independently 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 da4At least one of them is an aromatic hydrocarbon group which may have a substituent.)

[0295] [Chemical formula 25]

[0296]

[0297] (In formula (da-2), R da5 , R da6 , R da7 and R da8 are each independently a hydrocarbon group which may have a substituent, or a heterocyclic group which may have a substituent, and at least one of R da5 , R da6 , R da7 and R da8 is an aromatic hydrocarbon group which may have a substituent.)

[0298] As for the hydrocarbon group or heterocyclic group of R da1 to R da4 in formula (da-1), the number of carbon atoms 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.)

[0299] Regarding specific examples of the hydrocarbon group of R da1 to R da4 , there may be mentioned linear or branched alkyl groups, linear or branched alkenyl groups, linear or branched alkynyl groups, aromatic hydrocarbon groups, alicyclic hydrocarbon groups, aralkyl groups, etc.)

[0300] As described above, at least one of R da1 to R da4 is an aromatic group which may have a substituent, more preferably 3 or more of R da1 to R da4 are aromatic groups which may have a substituent, and particularly preferably all of R da1 to R da4 are aromatic groups which may have a substituent.)

[0301] Regarding R da1 to R da4The substituents that the alkyl group or heterocyclic group may have include haloalkyl groups having 1 to 18 carbon atoms, haloaliphatic cyclic groups having 3 to 18 carbon atoms, nitro groups, hydroxyl groups, cyano groups, alkoxy groups having 1 to 18 carbon atoms, aryloxy groups having 6 to 14 carbon atoms, aliphatic acyl groups having 2 to 19 carbon atoms, aromatic acyl groups having 7 to 15 carbon atoms, aliphatic acyloxy groups having 2 to 19 carbon atoms, aromatic acyloxy groups having 7 to 15 carbon atoms, alkylthio groups having 1 to 18 carbon atoms, arylthio groups having 6 to 14 carbon atoms, amino groups in which one or two hydrogen atoms bonded to the nitrogen atom may be substituted by an alkyl group having 1 to 18 carbon atoms, and halogen atoms.

[0302] When the hydrocarbon group as R da1 ~R da4 is an aromatic hydrocarbon group, the aromatic hydrocarbon group may be substituted by one or more substituents selected from the group consisting of alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and alkynyl groups having 2 to 18 carbon atoms.

[0303] When the hydrocarbon group as R da1 ~R da4 has substituents, the number of substituents is not particularly limited and may be one or two or more. When the number of substituents is two or more, the substituents may be the same or different from each other.

[0304] Preferred specific examples of the case where R da1 ~R da4 is an alkyl group include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, and n-icosyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, 2-ethylhexyl, and 1,1,3,3-tetramethylbutyl.

[0305] Preferred examples of the case where R da1 ~R da4 is an alkenyl group or an alkynyl group include alkenyl groups and alkynyl groups corresponding to the above-mentioned groups preferred as alkyl groups.

[0306] Preferred examples of the case where R da1 ~R da4 is an aromatic hydrocarbon group include phenyl, α-naphthyl, β-naphthyl, 4-biphenylyl, 3-biphenylyl, 2-biphenylyl, anthryl, and phenanthryl.

[0307] As R da1 ~R da4 When it is an alicyclic hydrocarbon group, preferred examples include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, cyclooctyl, cyclononyl, and cyclodecyl; crosslinked aliphatic alicyclic hydrocarbon groups such as norbornyl, adamantyl, tricyclodecyl, and pinanyl groups.

[0308] As R da1 ~R da4 When it is an aralkyl group, preferred examples include benzyl, phenethyl, α-naphthylmethyl, β-naphthylmethyl, α-naphthylethyl, and β-naphthylethyl.

[0309] As R da1 ~R da4 When it is a heterocyclic group, preferred examples include thienyl, furyl, selenophenyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidinyl, pyrazinyl, indolyl, benzofuryl, benzothienyl, quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, carbazolyl, acridinyl, phenothiazinyl, phenazinyl, xanthenyl, thianthrenyl, phenoxazinyl, phenoxathiinyl, chromanyl, isochromanyl, dibenzothiophenyl, xanthone, thioxanthone, and dibenzofuryl.

[0310] As R in formula (da-2) da5 ~R da8 , examples thereof include the same groups as those described above for R in formula (da-1) d a1 ~R da4 .

[0311] Preferred specific examples of the anionic part represented by formula (da-1) described above include:

[0312] tetrakis(4-nonafluorobiphenyl)gallium anion,

[0313] tetrakis(1-heptafluoronaphthyl)gallium anion,

[0314] tetrakis(pentafluorophenyl)gallium anion,

[0315] tetrakis(3,4,5-trifluorophenyl)gallate anion,

[0316] tetrakis(2-nonaphenylbiphenyl)gallium anion,

[0317] tetrakis(2-heptafluoronaphthyl)gallium anion,

[0318] tetrakis(7-nonafluoroanthryl)gallium anion,

[0319] tetrakis(4'-(methoxy)octafluorobiphenyl)gallium anion,

[0320] tetrakis(2,4,6-tris(trifluoromethyl)phenyl)gallium anion,

[0321] tetrakis(3,5-bis(trifluoromethyl)phenyl)gallium anion,

[0322] tetrakis(2,3-bis(pentafluoroethyl)naphthyl)gallium anion,

[0323] tetrakis(2-isopropoxy-hexafluoronaphthyl)gallium anion,

[0324] tetrakis(9,10-bis(heptafluoropropyl)heptafluoroanthryl)gallium anion,

[0325] tetrakis(9-nonafluorophenanthryl)gallate anion,

[0326] tetrakis(4-[tris(isopropyl)silyl]-tetrafluorophenyl)gallium anion,

[0327] tetrakis(9,10-bis(p-tolyl)-heptafluorophenanthryl)gallium anion, tetrakis(4-[dimethyl(tert-butyl)silyl]-tetrafluorophenyl)gallium anion, monophenyltris(pentafluorophenyl)gallium anion, and

[0328] monoperfluorobutyltris(pentafluorophenyl)gallium anion, etc.,

[0329] More preferably, the following anions can be mentioned.

[0330] [Chemical formula 26]

[0331]

[0332] In addition, as preferred specific examples of the anion moiety represented by formula (da-2), the following can be mentioned: tetrakis(4-nonafluorobiphenyl)boron anion,

[0333] tetrakis(1-heptafluoronaphthyl)boron anion,

[0334] tetrakis(pentafluorophenyl)boron anion,

[0335] tetrakis(3,4,5-trifluorophenyl)boron anion,

[0336] tetrakis(2-nonaphenylbiphenyl)boron anion,

[0337] tetrakis(2-heptafluoronaphthyl)boron anion,

[0338] tetrakis(7-nonafluoroanthryl)boron anion,

[0339] tetrakis(4'-(methoxy)octafluorobiphenyl)boron anion,

[0340] tetrakis(2,4,6-tris(trifluoromethyl)phenyl)boron anion,

[0341] tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion,

[0342] tetrakis(2,3-bis(pentafluoroethyl)naphthyl)borate anion,

[0343] tetrakis(2-isopropoxy-hexafluoronaphthyl)borate anion,

[0344] tetrakis(9,10-bis(heptafluoropropyl)heptafluoroanthryl)borate anion,

[0345] tetrakis(9-nonafluorophenanthryl)borate anion,

[0346] tetrakis(4-[tris(isopropyl)silyl]-tetrafluorophenyl)borate anion,

[0347] tetrakis(9,10-bis(p-tolyl)-heptafluorophenanthryl)borate anion,

[0348] tetrakis(4-[dimethyl(tert-butyl)silyl]-tetrafluorophenyl)borate anion,

[0349] monophenyltris(pentafluorophenyl)borate anion, and

[0350] monoperfluorobutyltris(pentafluorophenyl)borate anion, etc.,

[0351] More preferably, the following anions can be mentioned.

[0352] [Chemical formula 27]

[0353]

[0354] Among the counter anions exemplified above, CF 3 SO 3 - and ((C 6 F 5 ) 4 B) - . It should be noted that "C 6 F 5 " represents a pentafluorophenyl group.

[0355] As a preferred specific example of a compound containing a cation moiety formed from a cation represented by formula (dc) and an anion moiety, a quaternary ammonium salt containing a cation represented by formula (dc-1) and AsF 6- , a quaternary ammonium salt containing a cation represented by formula (dc-1) and SbF 6 - , a quaternary ammonium salt containing a cation represented by formula (dc-1) and PF 6 - , a quaternary ammonium salt containing a cation represented by formula (dc-1) and CF3 SO 3 - quaternary ammonium salts of, and cations represented by formula (dc-1) and ((C 6 F 5 ) 4 B) - quaternary ammonium salts of. Among them, quaternary ammonium salts containing cations represented by formula (dc-1) and CF 3 SO 3 - are more preferably used, and quaternary ammonium salts containing cations represented by formula (dc-1) and ((C 6 F 5 ) 4 B) - are also more preferably used.

[0356] The content of the thermal acid generator (D) in the photosensitive resin composition is not particularly limited as long as it does not hinder the object of the present invention. With respect to 100 parts by mass of the resin (A), the content of the thermal acid generator (D) in the photosensitive resin composition is preferably 0.1 part by mass or more and 15 parts by mass or less, more preferably 0.3 part by mass or more and 10 parts by mass or less, and particularly preferably 0.4 part by mass or more and 5 parts by mass or less from the viewpoint of transparency.

[0357] <Organic solvent (S)>

[0358] The photosensitive resin composition may contain an organic solvent (S). By including the organic solvent (S) in the photosensitive resin composition, it becomes easy to adjust the coatability 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.

[0359] Specific examples of the organic solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isopentyl ketone, 2-heptanone; polyhydric alcohols and their derivatives such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and dipropylene glycol monoacetate, and their monomethyl ethers (e.g., propylene glycol monomethyl ether acetate), monoethyl ethers, monopropyl ethers, monobutyl ethers, or monophenyl ethers; 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 ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate; aromatic hydrocarbons such as toluene, xylene; and the like.

[0360] In the photosensitive resin composition, relative to 100 parts by mass of the polyhydroxystyrene resin (A), the content of the organic solvent (S) is preferably 50 parts by mass or more and 3,000 parts by mass or less, more preferably 100 parts by mass or more and 2,000 parts by mass or less. If the content is within the above range, it is easy to improve the coatability of the photosensitive resin composition and easy to adjust the film thickness of the coating film formed using the photosensitive resin composition.

[0361] <Other components>

[0362] The photosensitive resin composition may contain various additives together with the above components within a range that does not impair the desired effects. The additives can be appropriately selected from various additives conventionally incorporated into the photosensitive resin composition. As specific examples of other components, quenching agents, polyvinyl resins, surfactants, and acids or acid anhydrides can be cited.

[0363] The photosensitive resin composition may contain a quenching agent. As the quenching agent, a low molecular compound (non-polymer) is usually used. As the quenching agent, for example, amines such as aliphatic amines and aromatic amines can be cited. As the quenching agent, an aliphatic amine is preferred, and an aliphatic secondary amine and an aliphatic tertiary amine are particularly preferred. Here, the so-called aliphatic amine is an amine having one or more aliphatic groups. The number of carbon atoms of the aliphatic group possessed by the aliphatic amine is preferably 1 or more and 20 or less.

[0364] As the aliphatic amine, for example, ammonia (NH 3 ) in which at least one of the hydrogen atoms is substituted by an alkyl group having 20 or less carbon atoms to form an alkylamine, ammonia (NH 3 ) in which at least one of the hydrogen atoms is substituted by a hydroxyalkyl group to form an alkanolamine, and cyclic amines can be cited.

[0365] As specific examples of the alkylamine and alkanolamine, monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine can be cited; 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; alkanolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, stearyl diethanolamine, and lauryl diethanolamine. Among them, trialkylamines and alkanolamines are preferred.

[0366] As the cyclic amine, for example, nitrogen-containing heterocyclic compounds can be cited. As the nitrogen-containing heterocyclic compound, it can be a monocyclic aliphatic amine or a polycyclic aliphatic amine.

[0367] As aliphatic monocyclic amines, specifically, piperidine, piperazine and the like can be mentioned. The number of carbon atoms of the aliphatic polycyclic amine is preferably 6 or more and 10 or less. As the aliphatic polycyclic amine, specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane and the like can be mentioned.

[0368] As other aliphatic amines, specifically, 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, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine and the like can be mentioned.

[0369] As aromatic amines, specifically, aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, 2,2'-bipyridine, 4,4'-bipyridine and the like can be mentioned.

[0370] The quencher can be used alone or in combination of two or more. With respect to 100 parts by mass of the polyhydroxystyrene resin (A), the amount of the quencher contained in the photosensitive resin composition is preferably 0.01 part by mass or more and 5.0 parts by mass or less.

[0371] In order to improve the plasticity of the formed film, the photosensitive resin composition may contain a polyethylene resin. Specific examples of the polyethylene resin include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoic acid, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylphenol and their copolymers and the like.

[0372] In order to improve the adhesiveness to the support, the photosensitive resin composition may contain an adhesion aid.

[0373] In order to improve coatability, defoaming property, leveling property, etc., the photosensitive resin composition may contain a surfactant. Specific examples of the surfactant include BM-1000, BM-1100 (both manufactured by BM CHEMI), MEGAFACE F142D, MEGAFACE F172, MEGAFACE F173, MEGAFACE F183 (all manufactured by DIC), Fluorad FC-135, Fluorad FC-170C, Fluorad FC-430, Fluorad FC-431 (all manufactured by Sumitomo 3M), Surflon S-112, Surflon S-113, Surflon S-131, Surflon S-141, Surflon S-145 (all manufactured by Asahi Glass), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (all manufactured by Toray Silicone), PolyFox PF-136A, PolyFox PF-156A, PolyFox PF-151N, PolyFox PF-636, PolyFox PF-656, PolyFox PF-6520 (all manufactured by OMNOVA Solutions), and other commercially available fluorosurfactants, but are not limited thereto.

[0374] In order to finely adjust the solubility in the developer, the photosensitive resin composition may contain an acid or an acid anhydride.

[0375] Specific examples of the acid and the acid anhydride include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, cinnamic acid; hydroxy monocarboxylic 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, syringic acid; polycarboxylic acids such as 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, trimellitic acid, pyromellitic acid, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid; acid anhydrides such as itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenylsuccinic anhydride, malonic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, nadic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bis(trimellitate), glycerol tris(trimellitate); and so on.

[0376] <Method for manufacturing a photosensitive resin composition>

[0377] The photosensitive resin composition can be prepared by mixing and stirring the above components using a conventional method. If necessary, a disperser such as a dissolver, a homogenizer, or a three-roll mill can also be used for dispersion and mixing. In addition, after mixing, a sieve, a membrane filter, etc. can be further used for filtration.

[0378] <Cured product>

[0379] By heating the aforementioned photosensitive resin composition, the polyhydroxystyrene resin (A) is crosslinked using the crosslinking agent (C) to form a cured product. Such a cured product has excellent chemical resistance.

[0380] <Method for manufacturing an optical element>

[0381] As described above, the photosensitive resin composition provides a cured product with excellent chemical resistance by heating. Therefore, the aforementioned photosensitive resin composition can be suitably used in a method for manufacturing an optical element having a plurality of microlenses including n types of microlenses on a substrate. In such a manufacturing method, the cured product of the photosensitive resin composition frequently contacts a chemical solution such as an organic solvent.

[0382] The n types of microlenses are different from each other. There is no particular limitation on the points where the n types of microlenses are different from each other. For example, the n types of microlenses are different from each other in one or more aspects such as 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, and shape. Typically, the n types of microlenses are different from each other in terms of size.

[0383] Hereinafter, a method for manufacturing an optical element having a plurality of microlenses including n types of microlenses on a substrate will be described.

[0384] 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. That is, it is preferable to manufacture an optical element having 2 types of microlenses.

[0385] The above manufacturing method includes the following steps:

[0386] A step of forming a resin film on a substrate;

[0387] A step of forming a mask having a shape corresponding to the shape of a plurality of microlenses on the resin film; and

[0388] A step of etching the resin film and the mask together to thereby form a plurality of microlenses having the shape of the mask transferred thereon.

[0389] A resin film is formed on a substrate as a lens material layer. As the substrate, substrates such as image elements including photodiodes (organic photodiodes, inorganic photodiodes, etc.), silicon wafers provided with a color filter layer, etc., and silicon wafers further formed with an antireflection film as the case may be can be cited.

[0390] Next, a mask having a shape corresponding to the shapes of a plurality of microlenses is formed on the resin film.

[0391] The mask is formed by repeating the following operations (i) to (iii) n times:

[0392] (i) An operation of coating a resin film with an m-th photosensitive resin composition to form an m-th coating film;

[0393] (ii) An operation of exposing and developing the m-th coating film to form an m-th dot at a position corresponding to the position where the m-th microlens is to be formed on the substrate; and

[0394] (iii) An operation of heating the m-th dot to deform the m-th dot into a shape corresponding to the shape of the m-th microlens.

[0395] The above m is an integer of 1 or more and n or less,

[0396] The first to n-th photosensitive resin compositions used in the formation of the mask may be the same or different.

[0397] At least one of the first to n-th photosensitive resin compositions is the photosensitive resin composition.

[0398] Hereinafter, a method for forming a mask having a microlens shape for forming the first microlens on the resin film will be described.

[0399] First, the first photosensitive resin composition is coated on the resin film to form a first coating film.

[0400] As the first photosensitive resin composition, the photosensitive resin composition used for forming a mask having a microlens shape in the above-described etching method can be used without particular limitation. As the first photosensitive resin composition, the photosensitive resin composition is preferably used.

[0401] The method for coating the first photosensitive resin composition is not particularly limited. For example, contact transfer type coating devices such as a roll coater, a reverse roll coater, a bar coater, and a slot coater, and non-contact type coating devices such as a spinner (rotary coating device) and a curtain coater can be used to coat the first photosensitive resin composition so as to have a desired film thickness, thereby forming a first coating film.

[0402] For the first coating film formed from the photosensitive resin composition, a heat treatment (pre-baking (PAB) treatment) can be appropriately performed to remove the solvent in the first coating film.

[0403] The conditions of the above heat treatment vary depending on the types of components of the photosensitive resin composition, the mixing ratio, the coating film thickness, etc. The heating temperature is preferably, for example, 60°C or higher and 150°C or lower, more preferably 70°C or higher and 140°C or lower. The heating time is preferably, for example, 0.5 minutes or longer and 60 minutes or shorter, more preferably 1 minute or longer and 50 minutes or shorter.

[0404] The film thickness of the first coating film is preferably in the range of 100 nm or more and 4.0 μm or less, more preferably in the range of 400 nm or more and 2.0 μm or less.

[0405] Next, the first coating film is exposed and developed to form a first dot at a position corresponding to the position where the first microlens is to be formed on the substrate.

[0406] The exposure is performed position-selectively so as to form a first dot at a specified position. The position-selective exposure can be performed, for example, through a desired mask pattern. The wavelength of the light used in the exposure is not particularly limited. The exposure can be performed using radiation such as KrF excimer laser, ArF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc.

[0407] Next, the exposed first coating film is developed. Thereby, the unnecessary portions are dissolved and removed. It is preferable that the coating film is not heated after exposure and before development.

[0408] Regarding the development, in the case of an alkali development process, an alkaline developer is used for development. In the case of a solvent development process, a developer containing an organic solvent (organic developer) is used for development.

[0409] As the alkaline developer, for example, an aqueous solution of alkalis 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 can be used. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and a surfactant to the aqueous solution of the above alkalis can also be used as the developer. As the alkaline developer, an aqueous solution of tetramethylammonium hydroxide with a concentration of 0.1 mass% or more and 10 mass% or less is preferred.

[0410] As the organic developing solution, an organic solvent capable of dissolving polyhydroxystyrene resin (A) (polyhydroxystyrene resin (A) before exposure) may be used. The organic solvent used in the form of the organic developing solution can be appropriately selected from known organic solvents. Preferred examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents.

[0411] The ketone solvent is an organic solvent having a structure represented by C-C(=O)-C. The ester solvent is an organic solvent having a carboxylic acid ester group. The alcohol solvent is an organic solvent having an alcoholic hydroxyl group. The nitrile solvent is an organic solvent having a nitrile group. The amide solvent is an organic solvent 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. The ether solvent is an organic solvent having an ether bond.

[0412] Among organic solvents, there are also organic solvents whose structures contain a plurality of functional groups that characterize the above-mentioned respective solvents. In this case, it is regarded as belonging to any solvent type containing the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether is regarded as belonging to any of the alcohol solvents and ether solvents in the above classification.

[0413] The hydrocarbon solvent is a hydrocarbon solvent formed from a halogenatable hydrocarbon and having no substituents other than halogen atoms. As the halogen atom, a fluorine atom is preferred.

[0414] Among the above, as the organic solvent contained in the organic developing solution, a polar solvent is preferred, and a ketone solvent, an ester solvent, and a nitrile solvent are preferred.

[0415] The development time also varies depending on the composition of the first photosensitive resin composition, the film thickness of the first coating film, etc., but is usually 20 seconds or more and 5 minutes or less. The development method can be any method such as the puddle method, the dipping method, the spin-dip method, the spray development method, etc.

[0416] After the developed first coating film is washed with running water or the like as needed, it is dried. By operating as described above, a dot pattern including the first dot is formed.

[0417] Next, the first dot is heated, whereby the first dot is deformed into a shape corresponding to the shape of the first microlens. By operating as described above, a mask having a shape corresponding to the shape of the first microlens can be formed on the resin film.

[0418] The heating conditions vary depending on the types of components, mixing ratios, coating film thickness, etc. in the first photosensitive resin composition. For example, the heating temperature is preferably 100°C or higher and 200°C or lower, more preferably 120°C or higher and 150°C or lower. The heating time is, for example, preferably 1 minute or longer and 30 minutes or shorter, more preferably 3 minutes or longer and 10 minutes or shorter.

[0419] Perform the operation as described above to form a mask on the resin film having a shape corresponding to the shape of the first microlens.

[0420] Next, on the resin film having a mask with a shape corresponding to the shape of the first microlens on its surface, use the second photosensitive resin composition to form a mask with a shape corresponding to the shape of the second microlens. The method of forming a mask with a shape corresponding to the shape of the second microlens is the same as the method of forming a mask with a shape corresponding to the shape of the first microlens.

[0421] As the second photosensitive resin composition, the aforementioned first photosensitive resin composition is preferred.

[0422] By repeating such an operation n times, n masks with shapes corresponding to the shapes of n types of microlenses are formed on the resin film.

[0423] For the resin film having n masks, perform etching in such a way that the resin film and the masks are etched together, whereby a plurality of microlenses with the shapes of the n masks transferred are formed on the substrate.

[0424] As described above, the inventors of the present application provide the following (1) to (9).

[0425] (1) A photosensitive resin composition comprising a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon irradiation with activating light or radiation, and a crosslinking agent (C),

[0426] In the polyhydroxystyrene resin (A), a part of the phenolic hydroxyl groups is protected with an acetal-type protecting group,

[0427] The crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups.

[0428] (2) The photosensitive resin composition according to (1), further comprising a thermal acid generator (D).

[0429] (3) The photosensitive resin composition according to (1) or (2), wherein the photoacid generator (B) is a photoacid generator (B-a) that generates an acid upon irradiation with activating light or radiation having an induction wavelength of 200 nm or more and 300 nm or less.

[0430] (4) The photosensitive resin composition according to any one of (1) to (3), wherein the photoacid generator (B) contains a diazomethane-based photoacid generator (B1) and / or an onium salt-based photoacid generator (B2).

[0431] (5) The photosensitive resin composition according to any one of (1) to (4), wherein, based on 100 parts by mass of the polyhydroxystyrene resin (A), 1.0 part by mass or more and 20 parts by mass or less of the crosslinking agent (C) is contained.

[0432] (6) A cured product of the photosensitive resin composition according to any one of (1) to (5).

[0433] (7) A method for manufacturing an optical element, the optical element having a plurality of microlenses including n kinds of microlenses on a substrate,

[0434] n is an integer of 2 or more,

[0435] The manufacturing method includes the following steps:

[0436] A step of forming a resin film on the substrate;

[0437] A step of forming a mask having a shape corresponding to the shape of the plurality of microlenses on the resin film; and

[0438] A step of etching the resin film and the mask together to thereby form a plurality of microlenses having the shape of the mask transferred thereto,

[0439] The mask is formed by repeating the following operations (i) to (iii) n times:

[0440] (i) An operation of coating the m-th photosensitive resin composition on the resin film to form the m-th coating film;

[0441] (ii) An operation of exposing and developing the m-th coating film to thereby form the m-th dot at a position corresponding to the position where the m-th microlens is to be formed on the substrate; and

[0442] (iii) An operation of heating the m-th dot to thereby deform the m-th dot into a shape corresponding to the shape of the m-th microlens,

[0443] m is an integer of 1 or more and n or less,

[0444] The first to n-th photosensitive resin compositions used in the formation of the mask may be the same or different,

[0445] At least one of the first to n-th photosensitive resin compositions is the photosensitive resin composition according to any one of (1) to (6),

[0446] When forming a coating film using the photosensitive resin composition according to any one of (1) to (6), the coating film is not heated after exposure and before development.

[0447] (8) The method for manufacturing an optical element according to (7), wherein n is 2.

[0448] (9) The method for manufacturing an optical element according to (8) or (9), wherein, in the formation of the mask, the photosensitive resin composition initially coated on the resin film is the aforementioned photosensitive resin composition.

[0449] Examples

[0450] Hereinafter, the present invention will be described in more detail using examples and comparative examples. The present invention is not limited to these examples.

[0451] [Examples 1 to 8, Comparative Example 1, and Comparative Example 2]

[0452] In the examples and comparative examples, as the polyhydroxystyrene resin (A), resin A-1 formed from the following units was used.

[0453] The weight-average molecular weight (Mw) in terms of polystyrene of resin A-1 measured by gel permeation chromatography was 20,000. The molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn)) of resin A-1 was 1.1.

[0454] [Chemical formula 28]

[0455]

[0456] In the examples and comparative examples, as the diazomethane-based photoacid generator (B1), the following B1-1 was used.

[0457] B1-1: bis(cyclohexylsulfonyl)diazomethane was used.

[0458] In the examples and comparative examples, as the onium salt-based acid generator (B2), the following B2-1 was used.

[0459] [Chemical formula 29]

[0460]

[0461] In the examples and comparative examples, as the crosslinking agent (C), the following compounds C-1 to C-3 were used.

[0462] [Chemical formula 30]

[0463]

[0464] In the examples and comparative examples, as the thermal acid generator (D), the following compounds D-1 and D-2 were used.

[0465] [Chemical formula 31]

[0466]

[0467] 100 parts by mass of the resin (A) of the type described in Table 1, the photoacid generator (B) of the type and amount described in Table 1, the crosslinking agent (C) of the amount described in Table 1, and the thermal acid generator (D) were dissolved in a mixed solvent (propylene glycol monomethyl ether acetate / ethyl lactate = 60 / 40 (mass ratio)) so that the solid component concentration became 10 wt%, to obtain the photosensitive resin compositions of the respective examples and comparative examples.

[0468] Using the obtained photosensitive resin compositions, the patterning characteristics of the photosensitive resin compositions and the chemical resistance of the cured film were evaluated according to the following method. The evaluation results thereof are shown in Table 1.

[0469] <Evaluation of patterning characteristics>

[0470] In a silicon substrate having an underlying antireflection film with a film thickness of 0.16 μm and a cured film of a thermosetting acrylic resin with a film thickness of 1 μm on its surface, the photosensitive resin compositions of the respective examples and comparative examples were coated on the cured film of the 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 coated film with a film thickness of 550 nm.

[0471] With respect to the formed coated film, through a mask for forming a dot pattern with a dot diameter of 0.40 μm and a dot pitch of 0.30 μm, exposure was performed using a KrF excimer laser (NSR-S203, manufactured by Nikon Corporation) at NA / s = 0.68 / 0.75.

[0472] The exposed coated film was brought into contact with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide at room temperature for 60 seconds for development.

[0473] Using a scanning electron microscope (SEM), the pattern shape formed on the silicon substrate after development was confirmed from the overhead and cross-sectional directions, and the patterning characteristics were evaluated according to the following criteria.

[0474] A: Can be resolved.

[0475] C: Cannot be resolved.

[0476] <Evaluation of chemical resistance>

[0477] In a silicon substrate having a lower antireflection film with a film thickness of 0.16 μm and a cured film of a thermosetting acrylic resin with a film thickness of 1 μm on its surface, the photosensitive resin compositions of each example and each comparative example were coated on the cured film of the 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 coated film with a film thickness of 550 nm.

[0478] With respect to the formed coated film, through a mask for forming dot patterns with a dot diameter of 0.40 μm and a dot pitch of 0.30 μm, exposure was performed using a KrF excimer laser (NSR-S203, manufactured by Nikon Corporation) at NA / s = 0.68 / 0.75.

[0479] The exposed coated film was brought into contact with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide at room temperature for 60 seconds for development.

[0480] After development, baking was performed at 140 °C for 5 minutes to obtain a silicon substrate (M1) having microlenses formed thereon.

[0481] Next, a KrF resist (TDUR-P3435, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was coated on the silicon substrate having microlenses formed thereon using a spin coater. The KrF resist coated on the silicon substrate was baked at 100 °C for 60 seconds to obtain a coated film with a film thickness of 550 nm.

[0482] With respect to the coated film, overall exposure was performed using a KrF excimer laser (NSR-S203, manufactured by Nikon Corporation) at NA / s = 0.68 / 0.75. The exposed coated film was baked at 100 °C for 90 seconds.

[0483] After baking, it was brought into contact with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide at room temperature for 60 seconds for development.

[0484] After development, baking was performed at 150 °C for 5 minutes to obtain a silicon substrate (M2) having microlenses formed thereon.

[0485] Based on the height T1 of the microlenses of M1 and the height T2 of the microlenses of M2, the residual film ratio was calculated based on the following formula.

[0486] Residual film ratio (%) = T2 / T1 × 100

[0487] Based on the calculated residual film ratio, the chemical resistance was evaluated according to the following criteria.

[0488] A: The residual film ratio of the lens height is 90% or more.

[0489] B: The residual film ratio of the lens height is 80% or more and less than 90%.

[0490] C: The residual film rate of the lens height is less than 80%.

[0491] [Table 1]

[0492]

[0493] As can be seen from Examples 1 to 8, in the photosensitive resin composition containing polyhydroxystyrene resin (A), photoacid generator (B) and crosslinking agent (C), by using a polyhydroxystyrene resin (A) in which a part of the phenolic hydroxyl groups is protected by an acetal-type protecting group, and a crosslinking agent (C) which is a polyfunctional epoxy compound having two or more epoxy groups in the molecule, a photosensitive resin composition excellent in lithography characteristics and capable of forming a micro-lens excellent in chemical resistance can be obtained.

Claims

1. A photosensitive resin composition comprising a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid by irradiation with activating light or radiation, and a crosslinking agent (C), In the polyhydroxystyrene resin (A), a part of the phenolic hydroxyl groups are protected by acetal type protecting groups. The crosslinking agent (C) is a polyfunctional epoxy compound (C1) having two or more epoxy groups. 2 . The photosensitive resin composition according to claim 1 , further comprising a thermal acid generator (D).

3. The photosensitive resin composition according to claim 1 or 2, wherein The photoacid generator (B) is a photoacid generator (Ba) that generates an acid in response to activating light or radiation having a wavelength of 200 nm to 300 nm.

4. The photosensitive resin composition according to claim 1 or 2, wherein The photoacid generator (B) includes a diazomethane photoacid generator (B1) and / or an onium salt photoacid generator (B2).

5. The photosensitive resin composition according to claim 1 or 2, wherein The crosslinking agent (C) is contained in an amount of 1.0 part by mass to 20 parts by mass based on 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, the optical element comprising a plurality of microlenses including n types of microlenses on a substrate, The n is an integer greater than 2, The manufacturing method comprises the following steps: forming a resin film on the substrate; forming a mask having a shape corresponding to the shape of the plurality of microlenses on the resin film; and a step of etching the resin film together with the mask to form the plurality of microlenses having a shape transferred from the mask, The mask is formed by repeating the following operations (i) to (iii) n times: (i) coating an m-th photosensitive resin composition on the resin film to form an m-th coating film; (ii) exposing and developing the mth coating film to form an mth dot at a position corresponding to a position on the substrate where the mth microlens is to be formed; and (iii) heating the m-th point, thereby deforming the m-th point into a shape corresponding to the shape of the m-th microlens, The m is an integer greater than 1 and less than 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 claim 1 or 2, 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 manufacturing an optical element according to claim 7, wherein: The n is 2.

9. The method for manufacturing an optical element according to claim 7, wherein: In forming the mask, the photosensitive resin composition first applied on the resin film is the aforementioned photosensitive resin composition.

Images