Photosensitive resin composition

Abstract

To provide a photosensitive resin composition which gives a microlens excellent in chemical resistance by a thermal flow method, a cured product of the photosensitive resin composition, a microlens composed of the cured product, and a method for producing an optical element using the photosensitive resin composition.SOLUTION: In a photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B), and a crosslinking agent (C), a polyhydrostyrene resin (A) in which a part of a phenolic hydroxyl group is protected with an acetal type protective group is used, and the photosensitive resin composition is configured to give a cured product showing a refractive index of 1.50 or more at a wavelength of 550 nm.SELECTED DRAWING: None

Description

[Technical field]

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

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

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

[0004] [Patent Document 1] JP 2020-100793 A Summary of the Invention [Problem to be solved by the invention]

[0005] The microlenses formed by the above-mentioned thermal flow method may be frequently exposed to chemicals such as organic solvents during the process of manufacturing an element equipped with the microlenses. For this reason, the photosensitive resin composition used in the thermal flow method is required to provide microlenses with excellent chemical resistance.

[0006] The present invention has been made in view of the above-mentioned conventional situation, and has an object to provide a photosensitive resin composition that can provide a microlens having excellent chemical resistance by a thermal flow method, a cured product of the photosensitive resin composition, a microlens made of the cured product, and a method for manufacturing an optical element using the above-mentioned photosensitive resin composition. [Means for solving the problem]

[0007] The present inventors have found that the above problems can be solved by using a polyhydroxystyrene resin (A) in which a portion of the phenolic hydroxyl groups are protected by an acetal-type protecting group in a photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B), and a crosslinking agent (C), and by configuring the photosensitive resin composition so as to give a cured product having a refractive index of 1.50 or more at a wavelength of 550 nm, and have arrived at the present invention. Specifically, the present invention provides the following.

[0008] A first aspect of the present invention is a composition comprising a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation, and a crosslinking agent (C), In the polyhydroxystyrene resin (A), a part of the phenolic hydroxyl groups is protected by an acetal-type protecting group, The photosensitive resin composition is a photosensitive resin composition that gives a cured product that exhibits a refractive index of 1.50 or more at a wavelength of 550 nm.

[0009] A second aspect of the present invention is a cured product of the photosensitive resin composition according to the first aspect.

[0010] A third aspect of the present invention is a microlens made of the cured product according to the second aspect.

[0011] A fourth aspect of the present invention is a method for producing a cured product, comprising heating the photosensitive resin composition according to the first aspect.

[0012] A fifth aspect of the present invention is A method for manufacturing an optical element having a plurality of microlenses on a substrate, comprising the steps of: Coating a photosensitive resin composition according to the first aspect on a substrate to form a coating film; exposing the coating film to light in a selective manner so that a plurality of dots are formed at positions on the substrate where a plurality of microlenses are to be formed; developing the exposed coating film to form a plurality of dots at positions where a plurality of microlenses are to be formed; and heating the plurality of dots to thermally deform the plurality of dots to form a plurality of microlenses; A manufacturing method in which the dots are exposed to light before heating the dots. Effect of the Invention

[0013] According to the present invention, it is possible to provide a photosensitive resin composition that can provide a microlens having excellent chemical resistance by a thermal flow method, a cured product of the photosensitive resin composition, a microlens made of the cured product, and a method for producing an optical element using the above-mentioned photosensitive resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] ≪Photosensitive resin composition≫ The photosensitive resin composition contains a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation, and a crosslinking agent (C). In the polyhydroxystyrene resin (A), some of the phenolic hydroxyl groups are protected with acetal-type protecting groups. The photosensitive resin composition having the above-mentioned features has excellent photolithography properties. Furthermore, when the photosensitive resin composition having the above-mentioned features is used, a microlens having excellent chemical resistance is formed by a thermal flow method. The photosensitive resin composition is configured to give a cured product having a refractive index of 1.50 or more at a wavelength of 550 nm. By using such a photosensitive resin composition, a microlens having high light-collecting efficiency can be formed. The refractive index of the cured product depends largely on the type of crosslinking agent (C). Therefore, the refractive index of the cured product can be increased by using a crosslinking agent (C) whose structure contributes to a high refractive index. In addition, various high refractive index materials can be blended into the photosensitive resin composition to increase the refractive index of the cured product, as long as the photolithography properties, thermal fluidity, crosslinking reactivity, and the like of the photosensitive resin composition are not significantly impaired.

[0015] <Polyhydroxystyrene resin (A)> The photosensitive resin composition contains a polyhydroxystyrene resin (A). In the polyhydroxystyrene resin (A), some of the phenolic hydroxyl groups are protected with acetal-type protecting groups. The polyhydroxystyrene resin (A) is effectively deprotected by the action of the acid generated by the photoacid generator (B) upon exposure to light, and is soluble in an alkaline developer. Therefore, when a patterned resin film is formed by a photolithography method including alkaline development using a photosensitive resin composition containing the polyhydroxystyrene resin (A), a resin film patterned into a desired shape can be easily obtained.

[0016] Suitable examples of the polyhydroxystyrene resin (A) include resins having a structural unit represented by the following formula (a1) and a structural unit represented by the following formula (a2). Hereinafter, the structural unit represented by formula (a1) will also be referred to as "structural unit (a1)". The structural unit represented by formula (a2) will also be referred to as "structural unit (a2)".

[0017] [ka] (In formula (a1), R a1 R is a hydrogen atom, an alkyl group, a halogen atom, or a halogenated alkyl group. a2 is a hydrogen atom or an alkyl group. p is an integer of 1 or more and 5 or less. q is an integer of 0 or more and 4 or less.

[0018] [ka] (In formula (a2), R a3 R is a hydrogen atom, an alkyl group, a halogen atom, or a halogenated alkyl group. a4 , R a5 , and R a6 are each independently a hydrogen atom or an alkyl group. a7 is an alkyl group or a cycloalkyl group; r is an integer of 1 or more and 5 or less; s and t are each independently an integer of 0 or more and 4 or less.

[0019] In formula (a1) and formula (a2), R a1 , and R a3 is a hydrogen atom, an alkyl group, a halogen atom, or a halogenated alkyl group. R a1 , and R a3 The number of carbon atoms in the alkyl group as R is not particularly limited as long as the desired effect is not impaired. a1 , and R a3 The number of carbon atoms in the alkyl group represented by R is preferably 1 or more and 5 or less. a1 , and R a3 The alkyl group as R may be linear or branched. a1, and R a3 Specific examples of the alkyl group as include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, and a neopentyl group, etc. From an industrial viewpoint, a methyl group is preferred.

[0020] R a1 , and R a3 Specific examples of the halogen atom as the halogen atom or the halogen atom in the halogenated alkyl include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred. As the halogenated alkyl group, a group in which a part or all of the hydrogen atoms in the above-mentioned alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms is preferred. The halogenated alkyl group may be linear or branched. Specific examples of suitable halogenated alkyl groups include fluorinated alkyl groups such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a nonafluorobutyl group.

[0021] R a1 , and R a3 is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0022] R a2 , and R a4 The number of carbon atoms in the alkyl group represented by R is preferably 1 or more and 5 or less. a2 , and R a4 Suitable examples of alkyl groups as R a1 , and R a3 The preferred examples of the alkyl group are the same as those of the alkyl group.

[0023] Each of q, s, and t is independently an integer of 0 to 4. Of these, q, s, and t are preferably 0 or 1, and are particularly preferably 0 from an industrial standpoint.

[0024] In formula (a1), when q is 1, R a2 The substitution position of is on the benzene ring in formula (a1),a1 The carbon atom bonded to the carbon atom bonded to the ring may be in any of the o-position, m-position, and p-position. If q is an integer between 2 and 4, inclusive, R a2 may be bonded to any position on the benzene ring in formula (a1).

[0025] In formula (a2), when t is 1, R a4 The substitution position of is on the benzene ring in formula (a2), R a3 The carbon atom bonded to the carbon atom bonded to the ring may be in any of the o-position, m-position, and p-position. If t is an integer between 2 and 4, R a4 may be bonded to any position on the benzene ring in formula (a2).

[0026] In formula (a1), p is an integer of 1 or more and 5 or less, preferably an integer of 1 or more and 3 or less, and more preferably 1. In formula (a2), s is an integer of 0 or more and 4 or less, preferably an integer of 0 or more and 3 or less, and more preferably 0 or 1. When p is 1 or s is 1, the substitution position of the hydroxyl group in formula (a1) and formula (a2) is R a1 , or R a3 The position may be any of the o-position, m-position, or p-position with respect to the position of the carbon atom bonded to the carbon atom bonded to the structural unit represented by formula (a1) or formula (a2), and the p-position is preferred because monomers that give the structural unit represented by formula (a1) or formula (a2) are easily available and low in cost. When p in formula (a1) is an integer of 2 or more and 5 or less, or when s in formula (a2) is an integer of 2 or more and 4 or less, the hydroxyl group may be bonded to any position on the benzene ring in formula (a1) and formula (a2).

[0027] In formula (a2), r is an integer of 1 or more and 5 or less, preferably an integer of 1 or more and 3 or less, and more preferably 1. When r is 1, -C(R a5 )(R a6 ) OR a7The substitution position of the group represented by a3 The carbon atom bonded to the carbon atom bonded to the ring may be in any of the o-position, m-position, and p-position. In formula (a2), when r is an integer of 2 or more and 5 or less, -C(R a5 )(R a6 ) OR a7 The group represented by the following formula (a2) can be bonded to any position on the benzene ring.

[0028] In formula (a2), -C(R a5 )(R a6 ) OR a7 In the acetal protecting group represented by the formula: a5 , and R a6 are each independently a hydrogen atom or an alkyl group. a7 is an alkyl group or a cycloalkyl group. a5 , R a6 , and R a7 At least two of these may be bonded to each other to form a ring.

[0029] R a5 , or R a6 The number of carbon atoms in the alkyl group represented by R is preferably 1 or more and 6 or less. a5 , or R a6 The alkyl group as may be linear or branched. R a7 The number of carbon atoms in the alkyl group represented by R is preferably 1 or more and 10 or less. a7 The alkyl group as may be linear or branched. R a7 The cycloalkyl group as the radical preferably has 3 or more and 10 or less carbon atoms, for example.

[0030] Ra 5 , R a6 , or R a7Specific examples of the alkyl group as include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, and a neopentyl group. R a7 Specific examples of the cycloalkyl group as the aryl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentyl group, and a cyclooctyl group.

[0031] In formula (a2), -C(R a5 )(R a6 ) OR a7 Specific examples of the acetal-type protecting group represented by the formula (I) include a 1-methoxyethyl group, a 1-ethoxyethyl group, a 1-n-propoxyethyl group, a 1-isopropoxyethyl group, a 1-n-butoxyethyl group, a 1-isobutoxyethyl group, a 1-tert-butoxyethyl group, a 1-cyclohexyloxyethyl group, a 1-methoxypropyl group, a 1-ethoxypropyl group, a 1-methoxy-1-methyl-ethyl group, and a 1-ethoxy-1-methylethyl group.

[0032] The polyhydroxystyrene resin (A) may contain one or more types of structural units (a1). The polyhydroxystyrene resin (A) may contain one or more types of structural units (a2). The sum of the ratio of the structural unit (a1) and the ratio of the structural unit (a2) in the polyhydroxystyrene resin (A) is preferably 50 mol% or more and 100 mol% or less, more preferably 70 mol% or more and 100 mol% or less, still more preferably 80 mol% or more and 100 mol% or less, particularly preferably 90 mol% or more and 100 mol% or less, and most preferably 100 mol% based on the number of moles of all structural units constituting the polyhydroxystyrene resin (A).

[0033] The ratio of the number of moles of the structural unit (a2) to the total number of moles of the structural unit (a1) and the number of moles of the structural unit (a2) is preferably 10 mol% or more and 60 mol% or less, more preferably 20 mol% or more and 40 mol% or less. This ratio is the protection rate of the hydroxyl group derived from the hydroxystyrene. When the protection rate is within the above range, it is easy to obtain a photosensitive resin composition with particularly good patterning properties.

[0034] The proportion of the number of moles of the structural unit (a2) relative to the number of moles of all structural units constituting the polyhydroxystyrene resin (A) is preferably from 10 mol % to 60 mol %, more preferably from 20 mol % to 40 mol %.

[0035] The polyhydroxystyrene resin (A) may contain a structural unit (a3) ​​other than the structural unit (a1) and the structural unit (a2). Other monomers that provide the other structural unit (a3) ​​include (meth)acrylic acid esters, (meth)acrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, maleimides, etc. These compounds can be used alone or in combination of two or more.

[0036] Examples of (meth)acrylic acid esters include linear or branched alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, amyl (meth)acrylate, and tert-octyl (meth)acrylate; chloroethyl (meth)acrylate, 2,2-dimethylhydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, benzyl (meth)acrylate, furfuryl (meth)acrylate; glycidyl (meth)acrylate; and (meth)acrylic acid esters having a group having an alicyclic skeleton. In the (meth)acrylic acid ester having a group having an alicyclic skeleton, the alicyclic group constituting the alicyclic skeleton may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic group include a norbornyl group, an isobornyl group, a tricyclononyl group, a tricyclodecyl group, and a tetracyclododecyl group.

[0037] Examples of (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, N-aryl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, N,N-aryl(meth)acrylamide, N-methyl-N-phenyl(meth)acrylamide, and N-hydroxyethyl-N-methyl(meth)acrylamide.

[0038] Examples of allyl compounds include allyl esters such as allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, and allyl lactate; allyloxyethanol; and the like.

[0039] Examples of vinyl ethers include aliphatic vinyl ethers such as hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, and tetrahydrofurfuryl vinyl ether; and vinyl aryl ethers such as vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, and vinyl anthranyl ether.

[0040] Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valerate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl phenylacetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, and vinyl naphthoate.

[0041] Examples of styrenes include styrene; alkyl styrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, and acetoxymethylstyrene; alkoxy styrenes such as methoxystyrene, 4-methoxy-3-methylstyrene, and dimethoxystyrene; and halostyrenes such as chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, and 4-fluoro-3-trifluoromethylstyrene.

[0042] Examples of maleimides include maleimides N-substituted with an alkyl group having 1 to 10 carbon atoms, such as N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, Nn-pentylmaleimide, and Nn-hexylmaleimide; maleimides N-substituted with an alicyclic group having 3 to 20 carbon atoms, such as N-cyclopentylmaleimide, N-cyclohexylmaleimide, and N-cycloheptylmaleimide; N-arylmaleimides N-substituted with an aryl group having 6 to 20 carbon atoms, such as N-phenylmaleimide, N-α-naphthylmaleimide, and N-β-naphthylmaleimide; and N-aralkylmaleimides N-substituted with an aralkyl group having 7 to 20 carbon atoms, such as N-benzylmaleimide and N-phenethylmaleimide.

[0043] The weight average molecular weight (Mw) of the polyhydroxystyrene resin (A) is preferably from 5000 to 30000. In this specification, the weight average molecular weight is a polystyrene-equivalent weight average molecular weight determined by gel permeation chromatography (GPC).

[0044] <Photoacid generator (B)> The photosensitive resin composition contains a photoacid generator (B) that generates an acid upon irradiation with actinic rays or radiation. The photoacid generator (B) generates an acid upon exposure to light, which deprotects the polyhydroxystyrene resin (A) and makes it soluble in an alkaline developer, making the photosensitive resin composition suitable for patterning by photolithography. In addition, by forming multiple dots using a thermal flow method including a photolithography process, and then exposing the multiple dots to light before thermally modifying the multiple dots to form microlenses, a microlens with excellent chemical resistance is formed. This is because exposure to light generates acid in the dots. By deforming the dots containing the acid with heat, crosslinking of the polyhydroxystyrene resin (A) by the crosslinking agent (C) proceeds smoothly, and microlenses can be formed.

[0045] The photoacid generator (B) is not particularly limited, and any photoacid generator that has been blended in a photosensitive resin composition can be used without particular limitation. Examples of the photoacid generator (B) include onium salt-type photoacid generators such as iodonium salts and sulfonium salts; sulfonate-type photoacid generators such as oximesulfonate-type photoacid generators and imide sulfonate-type photoacid generators; diazomethane-type photoacid generators; and disulfone-type photoacid generators. Among these, the sulfonate-type photoacid generators and the onium salt-type photoacid generators are preferred because they are capable of easily producing a photosensitive resin composition having excellent photolithography properties. That is, it is preferable that the photoacid generator (B) contains a sulfonate-type photoacid generator (B1) and / or an onium salt-type photoacid generator (B2). The sulfonate-type photoacid generator (B1) and the onium salt-type photoacid generator (B2) will be described below.

[0046] [Sulfonate-type photoacid generator (B1)] The sulfonate-type photoacid generator (B1) is -O-SO 2 There is no particular limitation as long as the compound has a sulfonate structure represented by the formula (I). As the sulfonate-type photoacid generator (B1), for example, a compound represented by the following formula (b0-1) is preferable.

[0047] [ka]

[0048] In formula (b0-1), Rb 1 is an organic group. 2 is a group represented by the following formula (b0-r-1) or the following formula (b0-r-2).

[0049] [ka]

[0050] In formula (b0-r-1), Rb201 , and Rb 202 are each independently an organic group. * indicates a bond. In formula (b0-r-2), Xb is a group that forms a cyclic group having a cyclic imide structure together with -(O=)CNC(=O)-. * represents a bond.]

[0051] Suitable examples of the compound represented by formula (b0-1) include compounds represented by any of the following formulas (b0-1-1) to (b0-1-6). As the sulfonate type photoacid generator (B1), an oxime sulfonate type photoacid generator (B1-1) and an imide sulfonate type photoacid generator (B1-2) are preferred. The compound represented by any one of the following formulas (b0-1-1) to (b0-1-6) is >C=NO-SO 2 -, or >NO-SO 2 - is an imide sulfonate compound having the structure represented by the formula: >NO-SO 2 The nitrogen atom in the structure represented by - constitutes a dicarboxylic acid imide ring.

[0052] [ka]

[0053] In formula (b0-1-1), Rb 11 , and Rb 21 are each independently an aliphatic group.

[0054] [ka]

[0055] In formula (b0-1-2), Rb 12 is an alkyl group or a halogenated alkyl group. 22 is an aromatic group.

[0056] [ka]

[0057] In formula (b0-1-3), Rb 13 is a hydrocarbon group which may have a substituent, or a heterocyclic group which may have a substituent. nb3 is 2 or 3. Ab is a divalent or trivalent organic group.

[0058] [ka]

[0059] In formula (b0-1-4), Rb 14 Rb is a polycyclic aromatic hydrocarbon group which may have a substituent, or a polycyclic aliphatic hydrocarbon group which may have a substituent and may have an unsaturated bond. 24 is an inert organic group.

[0060] [ka]

[0061] In formula (b0-1-5), Rb 15 Xb is a monovalent aliphatic hydrocarbon group which may have a substituent and may have an unsaturated bond, or an aromatic group which may have a substituent. 5 is a group which forms a cyclic group having a cyclic imide structure together with -(O=)CNC(=O)-.

[0062] [ka]

[0063] In formula (b0-1-6), Rb 16 Rb is an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. 261 ~Rb 263are each independently a halogen atom, an alkyl group having from 1 to 6 carbon atoms, or an alkoxy group having from 1 to 6 carbon atoms. nb6 is an integer of 0 to 5.

[0064] In formula (b0-1-1), Rb 11 , and Rb 21 Examples of the aliphatic group as the alkyl group include an alkyl group, a halogenated alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an alkoxy group, a cycloalkoxy group, and an adamantyl group.

[0065] Rb 11 , and Rb 21 The alkyl group as the alkyl group is preferably a linear or branched alkyl group having from 1 to 12 carbon atoms. Specific examples of the alkyl group having from 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-octyl group, and an n-dodecyl group.

[0066] Rb 11 , and Rb 21 The number of halogen atoms in the halogenated alkyl group as is not particularly limited. The number of halogen atoms may be 1 or 2 or more. The halogen atom may be any of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated alkyl group is preferably a halogenated alkyl group having from 1 to 4 carbon atoms. Specific examples of the halogenated alkyl group having from 1 to 4 carbon atoms include a chloromethyl group, a trichloromethyl group, a trifluoromethyl group, and a 2-bromopropyl group.

[0067] Rb 11 , and Rb 21 The alkenyl group as the alkyl group is preferably a linear or branched alkenyl group having from 2 to 6 carbon atoms. Preferred alkenyl groups having from 2 to 6 carbon atoms include a vinyl group, a 1-propenyl group, an isopropenyl group, and a 2-butenyl group.

[0068] Rb 11 , and Rb 21 The cycloalkyl group as the radical is preferably a cycloalkyl group having 5 to 12 carbon atoms. Preferred cycloalkyl groups having 5 to 12 carbon atoms include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, and a cyclododecyl group.

[0069] Rb 11 , and Rb 21 The cycloalkenyl group as the aryl group is preferably a cycloalkenyl group having 4 to 8 carbon atoms. Preferred cycloalkenyl groups having 4 to 8 carbon atoms include a 1-cyclobutenyl group, a 1-cyclopentenyl group, a 1-cyclohexenyl group, a 1-cycloheptenyl group, and a 1-cyclooctenyl group.

[0070] Rb 11 , and Rb 21 The alkoxy group as the aryl group is preferably an alkoxy group having from 1 to 8 carbon atoms. Preferred alkoxy groups having from 1 to 8 carbon atoms include a methoxy group, an ethoxy group, an n-propyloxy group, an n-butyloxy group, and an n-pentyloxy group.

[0071] Rb 11 and Rb 21 The cycloalkoxy group as the aryl group is preferably a cycloalkoxy group having 5 to 8 carbon atoms. Preferred cycloalkoxy groups having 5 to 8 carbon atoms include a cyclopentyloxy group and a cyclohexyloxy group.

[0072] Rb in formula (b0-1-1) 11 As the alkyl group, an alkyl group, a halogenated alkyl group, and a cycloalkyl group are preferable, and an alkyl group is more preferable. Rb 21 As the alkyl group, an alkyl group, a cycloalkyl group, and a cycloalkenyl group are preferable, and a cycloalkenyl group is more preferable. In formula (b0-1-1), Rb 11is an alkyl group having 1 to 4 carbon atoms, and Rb 21 is particularly preferably a cyclopentenyl group.

[0073] Specific examples of the compound represented by formula (b0-1-1) include α-(methylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(methylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(methylsulfonyloxyimino)-1-cycloheptenylacetonitrile, α-(methylsulfonyloxyimino)-1-cyclooctenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-cyclohexylacetonitrile, α-(ethylsulfonyloxyimino)-ethylacetonitrile, α-(propylsulfonyloxyimino)-propylacetonitrile, and α-(cyclohexylsulfonyloxyimino).

[0113] Examples of the acetonitrile include α-(cyclohexylsulfonyloxyimino)-cyclohexylacetonitrile, α-(cyclohexylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(isopropylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(n-butylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(isopropylsulfonyloxyimino)-1-cyclohexenylacetonitrile, and α-(n-butylsulfonyloxyimino)-1-cyclohexenylacetonitrile.

[0074] Rb in formula (b0-1-2) 12 Examples of the alkyl group as the alkyl group include linear or branched alkyl groups having from 1 to 4 carbon atoms. Specific examples of the alkyl group having from 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

[0075] Rb 12 As the halogenated alkyl group, there can be mentioned a halogenated alkyl group having from 1 to 4 carbon atoms. Specific examples of the halogenated alkyl group having from 1 to 4 carbon atoms include a chloromethyl group, a trichloromethyl group, a trifluoromethyl group, and a 2-bromopropyl group.

[0076] In formula (b0-1-2), Rb 22 The aromatic group as a substituent is a group that exhibits physical and chemical properties specific to aromatic compounds. Specific examples of aromatic groups include phenyl, naphthyl, furyl, and thienyl groups. Rb 22 The aromatic group as may have one or more substituents, such as a halogen atom, an alkyl group, an alkoxy group, and a nitro group.

[0077] Specific examples of the compound represented by formula (b0-1-2) include α-(methylsulfonyloxyimino)-phenylacetonitrile, α-(methylsulfonyloxyimino)-4-methoxyphenylacetonitrile, α-(methylsulfonyloxyimino)-4-methylphenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-phenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-4-methoxyphenylacetonitrile, α-(ethylsulfonyloxyimino)-4-methoxyphenylacetonitrile, α-(propylsulfonyloxyimino)-4-methylphenylacetonitrile, and α-(methylsulfonyloxyimino)-4-bromophenylacetonitrile.

[0078] In formula (b0-1-3), Rb 13 Examples of the optionally substituted hydrocarbon group as the aryl group include an optionally substituted aromatic hydrocarbon group and an optionally substituted aliphatic hydrocarbon group. The aromatic group is preferably a hydrocarbon group having 6 to 14 carbon atoms. Specific examples of the aromatic hydrocarbon group which may have a substituent include a phenyl group, a tolyl group, a methoxyphenyl group, a xylyl group, a biphenyl group, a naphthyl group, and an anthryl group.

[0079] Rb 13 The aliphatic hydrocarbon group as may be a chain aliphatic hydrocarbon group or an alicyclic hydrocarbon group. Examples of the aliphatic hydrocarbon group include an alkyl group, an alkenyl group, a cycloalkyl group, and a cycloalkenyl group. The alkyl group and the alkenyl group may be linear or branched. The number of carbon atoms in the alkyl group and the alkenyl group is preferably 1 or more and 12 or less. The cycloalkyl group and the cycloalkenyl group preferably have 4 or more and 12 or less carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-octyl group, and an n-dodecyl group. Specific examples of the alkenyl group include an ethenyl group, a propenyl group, a butenyl group, and a hexenyl group. Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, and a cyclododecyl group. Examples of the cycloalkenyl group include a 1-cyclobutenyl group, a 1-cyclopentenyl group, a 1-cyclohexenyl group, a 1-cycloheptenyl group, and a 1-cyclooctenyl group.

[0080] Rb 13 The heterocyclic group may be an aromatic heterocyclic group or an aliphatic heterocyclic group. The heterocyclic group is preferably an aromatic heterocyclic group. Specific examples of the aromatic heterocyclic group include a furanyl group, a pyridyl group, and a quinolyl group.

[0081] Rb in formula (b0-1-3) 13The hydrocarbon group and the heterocyclic group may have a substituent, such as a halogen atom, a hydroxyl group, an alkoxy group, and an acyl group.

[0082] Examples of the divalent or trivalent organic group as Ab in formula (b0-1-3) include divalent or trivalent aliphatic hydrocarbon groups, and divalent or trivalent aromatic hydrocarbon groups.

[0083] Specific examples of the compound represented by formula (b0-1-3) are shown below.

[0084] [ka]

[0085] [ka]

[0086] Rb in formula (b0-1-4) 14 Examples of the polycyclic aromatic hydrocarbon group as the aromatic ring include condensed polycyclic aromatic hydrocarbon groups such as a 2-indenyl group, a 1-naphthyl group, a 2-naphthyl group, and a 2-anthryl group; and non-condensed polycyclic aromatic hydrocarbon groups such as a biphenyl group and a terphenyl group. The polycyclic aromatic hydrocarbon group may have a substituent such as a halogen atom, such as a chlorine atom, a bromine atom, or an iodine atom, a nitro group, an amino group, a hydroxyl group, an alkyl group, or an alkoxyl group. Specific examples of the substituted polycyclic aromatic hydrocarbon group include a 5-hydroxynaphthalene-1-yl group and a 4-aminonaphthalene-1-yl group.

[0087] Rb in formula (b0-1-4) 14 Examples of the polycyclic aliphatic hydrocarbon group which may have an unsaturated bond as the aryl group include a polycyclic terpene residue, adamantyl, etc. As the polycyclic aliphatic hydrocarbon group, a polycyclic terpene residue is preferable. The polycyclic aliphatic hydrocarbon group may have a substituent such as a halogen atom, such as a chlorine atom, a bromine atom, or an iodine atom, a nitro group, an amino group, a hydroxyl group, an alkyl group, or an alkoxyl group.

[0088] Rb 14 In the polycyclic aliphatic hydrocarbon group as above, one or more methylene groups constituting the polycyclic aliphatic hydrocarbon group may be substituted with a carbonyl group (>C=O). However, in the polycyclic aliphatic hydrocarbon group, all methylene groups are not substituted with carbonyl groups.

[0089] Rb 14 Suitable examples of the polycyclic aliphatic hydrocarbon group as the radical include a camphor-3-yl group, a camphor-8-yl group, a camphor-10-yl group, and a 3-bromocamphor-10-yl group.

[0090] Among the groups described above, Rb 14 As the alkyl group, a naphthyl group and a camphor-10-yl group are preferred, and a 1-naphthyl group is particularly preferred in that the photosensitive resin composition has excellent resolution.

[0091] In formula (b0-1-4), Rb 24 The inert organic group as the radical is not particularly limited so long as it is an organic group that is inert to coexisting components under the conditions of use. The inert organic group is preferably an aromatic group in terms of sensitivity to excimer lasers, electron beams, and X-rays. Examples of the aromatic group include a phenyl group, a naphthyl group, a furyl group, and a thienyl group. The aromatic group may have an inert substituent such as a halogen atom, such as a chlorine atom, a bromine atom, or an iodine atom, an alkyl group, an alkoxy group, or a nitro group.

[0092] Specific examples of the compound represented by formula (b0-1-4) include α-(1-naphthylsulfonyloxyimino)-4-methoxybenzyl cyanide, α-(2-naphthylsulfonyloxyimino)-4-methoxybenzyl cyanide, α-(1-naphthylsulfonyloxyimino)benzyl cyanide, α-(2-naphthylsulfonyloxyimino)benzyl cyanide, α-(10-camphorsulfonyloxyimino)-4-methoxybenzyl cyanide, α-(10-camphorsulfonyloxyimino)benzyl cyanide, α-(3-camphorsulfonyloxyimino)-4-methoxybenzyl cyanide, and α-(3-bromo-10-camphorsulfonyloxyimino)-4-methoxybenzyl cyanide.

[0093] Rb in formula (b0-1-5) 15 The number of carbon atoms in the monovalent aliphatic hydrocarbon group which may have a substituent or an unsaturated bond as referred to above is preferably from 1 to 8. The number of carbon atoms does not include the carbon atoms of the substituent. The structure of the aliphatic hydrocarbon group may be straight-chain, branched-chain, or cyclic, or may be a combination of these structures. Examples of the substituent include a halogen atom, a nitro group, an acetylamino group, an alkoxy group, a phenyl group, etc. Among these substituents, a halogen atom and an alkoxy group are preferred. Rb 15 Examples of the aromatic group which may have a substituent as the substituent include a monocyclic aromatic group and a bicyclic aromatic group. The aromatic group is preferably a phenyl group substituted with one or more groups selected from a vinyl group, an alkyl group, an alkoxy group, a halogen atom, and the like.

[0094] In formula (b0-1-5), Xb 5 Examples of the ring having a cyclic imide structure formed by -(O=)CNC(=O)- include a succinimide ring, a maleimide ring, a glutarimide ring, a phthalimide ring, and a naphthalimide ring. Xb 5The ring having a cyclic imide structure formed by -(O=)CNC(=O)- may have a substituent, such as a halogen atom, a nitro group, an acetylamino group, an alkoxy group, or a phenyl group.

[0095] Specific examples of the compound represented by formula (b0-1-5) include N-methylsulfonyloxysuccinimide, N-isopropylsulfonyloxysuccinimide, N-chloroethylsulfonyloxysuccinimide, N-(p-methoxyphenyl)sulfonyloxysuccinimide, N-(p-vinylphenyl)sulfonyloxysuccinimide, N-naphthylsulfonyloxysuccinimide, N-phenylsulfonyloxysuccinimide, N-(2,4,6-trimethylphenyl)sulfonyloxysuccinimide, N-methylsulfonyloxymaleimide, N-isopropylsulfonyloxymaleimide, N-chloroethylsulfonyloxymaleimide, N-(p-methoxyphenyl)sulfonyloxymaleimide, N-(p-vinylphenyl)sulfonyloxysuccinimide, Examples of the sulfonyloxyphthalimide include N-phenylsulfonyloxymaleimide, N-naphthylsulfonyloxymaleimide, N-phenylsulfonyloxymaleimide, N-(2,4,6-trimethylphenyl)sulfonyloxymaleimide, N-methylsulfonyloxyphthalimide, N-isopropylsulfonyloxyphthalimide, N-chloroethylsulfonyloxyphthalimide, N-(p-methoxyphenyl)sulfonyloxyphthalimide, N-(p-vinylphenyl)sulfonyloxyphthalimide, N-naphthylsulfonyloxyphthalimide, N-phenylsulfonyloxyphthalimide, and N-(2,4,6-trimethylphenyl)sulfonyloxyphthalimide, as well as the compounds described in paragraphs

[0089] to

[0091] of JP-A-10-097075.

[0096] In formula (b0-1-6), Rb 16As the alkyl group, a linear or branched alkyl group having 1 to 18 carbon atoms is preferable, a linear or branched alkyl group having 1 to 10 carbon atoms is more preferable, and a linear or branched alkyl group having 1 to 5 carbon atoms is even more preferable. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, a 2,4,4-trimethylpentyl group, a 2-ethylhexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, and an n-octadecyl group.

[0097] In formula (b0-1-6), Rb 16 As the cycloalkyl group, a cycloalkyl group having 3 to 18 carbon atoms is preferable. Rb 16 Examples of the cycloalkyl group as the aryl group include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, and a cyclododecyl group.

[0098] Rb 16 The alkyl group and the cycloalkyl group as may have a substituent, such as a halogen atom, a halogenated alkyl group, a cyano group, a nitro group, a phenyl group, an alkoxy group, a carboxy group, a sulfonyl group, and an amino group.

[0099] Rb 16 In the alkyl group or cycloalkyl group represented by the formula (I), one or more methylene groups constituting the alkyl group or cycloalkyl group may be substituted with a carbonyl group (>C=O). However, in the alkyl group or cycloalkyl group, all methylene groups are not substituted with carbonyl groups.

[0100] In formula (b0-1-6), Rb 16Examples of the aromatic group as the aromatic ring include a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, and a heteroaryl group. Rb 16 The aromatic group as may have a substituent, such as a halogen atom, a halogenated alkyl group, a cyano group, a nitro group, a phenyl group, an alkoxy group, a carboxy group, a sulfonyl group, and an amino group.

[0101] Specific examples of the compound represented by formula (b0-1-6) include the compound represented by the following formula (b0-1-61) and the compounds of Examples 25 to 40 and 53 of JP-T2002-508774.

[0102] [ka]

[0103] Other specific examples of the sulfonate-type photoacid generator (B1) other than the sulfonate-type photoacid generator (B1) described above include the compounds described in paragraphs

[0056] ,

[0058] ,

[0060] , and

[0063] of Japanese Patent No. 4,110,392, and the compounds described in paragraphs

[0053] ,

[0054] ,

[0056] ,

[0058] , and paragraphs

[0060] to

[0062] of Japanese Patent No. 4,000,469.

[0104] Of the sulfonate-type photoacid generators (B1) described above, at least one selected from the group consisting of compounds represented by formula (b0-1-2), compounds represented by formula (b0-1-3), compounds represented by formula (b0-1-5), and compounds represented by formula (b0-1-6) is preferred, and at least one selected from the group consisting of compounds represented by formula (b0-1-2), compounds represented by formula (b0-1-3), and compounds represented by formula (b0-1-6) is more preferred.

[0105] As the sulfonate-type photoacid generator (B1), the compounds represented by the following formulas (B0-1) to (B0-3) are particularly preferred.

[0106] [ka]

[0107] [Onium salt type photoacid generator (B2)] As the onium salt type photoacid generator (B2), any of the conventionally known onium salt type photoacid generators such as iodonium salts and sulfonium salts can be used without any particular limitation.

[0108] The onium salt type photoacid generator (B2) includes onium salts having a naphthalene ring in the cation part. The term "having a naphthalene ring" means that the structure is derived from naphthalene, and that at least two ring structures and their aromaticity are maintained. The naphthalene ring may have a substituent such as a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. The structure derived from the naphthalene ring may be a monovalent group (one free valence) or a divalent group (two or more free valences), but is preferably a monovalent group (however, in this case, the free valence is counted excluding the portion bonded to the above-mentioned substituent). The number of naphthalene rings is preferably 1 to 3.

[0109] The cation moiety of such an onium salt having a naphthalene ring at the cation moiety is preferably a structure represented by the following formula (b1).

[0110] [ka]

[0111] In the above formula (b1), R 1b , R 2b , R 3b At least one of R represents a group represented by the following formula (b2), and the rest represent a linear or branched alkyl group having 1 to 6 carbon atoms, a phenyl group which may have a substituent, or a linear or branched alkoxy group having 1 to 6 carbon atoms.1b , R 2b , R 3b one of them is a group represented by the following formula (b2), and the remaining two are each independently a linear or branched alkylene group having from 1 to 6 carbon atoms, and the ends of these may be bonded to form a ring. R 1b , R 2b , R 3b Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms as the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. R 1b , R 2b , R 3b Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms as the aryl group include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, an n-pentyloxy group, and an n-hexyloxy group. R 1b , R 2b , R 3b When is a phenyl group which may have a substituent, preferred substituents include a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, and a linear or branched alkyl group having 1 to 6 carbon atoms.

[0112] [ka]

[0113] In the above formula (b2), R 4b , R 5b each independently represents a hydroxyl group, a linear or branched alkoxy group having from 1 to 6 carbon atoms, or a linear or branched alkyl group having from 1 to 6 carbon atoms; R 6brepresents a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms which may have a substituent. l and m each independently represent an integer of 0 to 2, and l+m is 3 or less. 4b When there are multiple R, they may be the same or different. 5b When multiple are present, they may be the same or different. R 4b , and R 5b Specific examples of the linear or branched alkoxy group having 1 to 6 carbon atoms as the alkoxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, an n-pentyloxy group, and an n-hexyloxy group. R 4b , and R 5b Specific examples of the linear or branched alkyl group having 1 to 6 carbon atoms as the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. R 6b Specific examples of the linear or branched alkylene group having 1 to 6 carbon atoms as the alkyl group include a methylene group, an ethane-1,2-diyl group (ethylene group), an ethane-1,1-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group.

[0114] Above R 1b , R 2b , R 3bAmong these, the number of groups represented by the above formula (b2) is preferably one from the viewpoint of the stability of the compound, and the rest are linear or branched alkylene groups having 1 to 6 carbon atoms, the ends of which may be bonded to form a ring. In this case, the above two alkylene groups form a 3- to 9-membered ring including the sulfur atom. The number of atoms (including the sulfur atom) constituting the ring is preferably 5 to 6.

[0115] Furthermore, examples of the substituent that the alkylene group may have include an oxygen atom (which in this case forms a carbonyl group together with the carbon atom that constitutes the alkylene group) and a hydroxyl group.

[0116] In addition, examples of the substituent that the phenyl group may have include a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, and a linear or branched alkyl group having 1 to 6 carbon atoms.

[0117] Suitable examples of these cationic moieties include those represented by the following formulae (b3), (b4-1), and (b4-2), and in particular, the structures represented by the following formulae (b4-1) and (b4-2) are preferred.

[0118] [ka]

[0119] Such a cationic moiety may be either an iodonium salt or a sulfonium salt, but from the standpoint of acid generation efficiency and the like, a sulfonium salt is preferred.

[0120] Therefore, the anion moiety of an onium salt having a naphthalene ring in the cation moiety is preferably an anion capable of forming a sulfonium salt.

[0121] The anion portion of such an acid generator is a fluoroalkylsulfonate ion or an arylsulfonate ion in which some or all of the hydrogen atoms have been fluorinated.

[0122] The alkyl group in the fluoroalkylsulfonate ion may be linear, branched, or cyclic and have 1 to 20 carbon atoms, and preferably has 1 to 10 carbon atoms in view of the bulkiness of the generated acid and its diffusion distance. In particular, branched or cyclic groups are preferred because they have a short diffusion distance. In addition, preferred groups include methyl, ethyl, propyl, butyl, and octyl groups because they can be synthesized at low cost.

[0123] The aryl group in the arylsulfonate ion is an aryl group having 6 to 20 carbon atoms, and examples thereof include an alkyl group, a phenyl group which may or may not be substituted with a halogen atom, and a naphthyl group. In particular, an aryl group having 6 to 10 carbon atoms is preferred because it can be synthesized at low cost. Specific examples of preferred groups include a phenyl group, a toluenesulfonyl group, an ethylphenyl group, a naphthyl group, and a methylnaphthyl group.

[0124] In the above-mentioned fluoroalkylsulfonate ion or arylsulfonate ion, when some or all of the hydrogen atoms are fluorinated, the fluorination rate is preferably 10% or more and 100% or less, more preferably 50% or more and 100% or less, and in particular, those in which all the hydrogen atoms are replaced with fluorine atoms are preferred because they have a stronger acid strength.Specific examples of such ions include trifluoromethanesulfonate, perfluorobutanesulfonate, perfluorooctane sulfonate, and perfluorobenzenesulfonate.

[0125] Among these, preferred anion moieties include those represented by the following formula (b5).

[0126] [ka]

[0127] In the above formula (b5), R 7b are groups represented by the following formulae (a10), (a11), and (a12).

[0128] [ka]

[0129] In the above formula (b6), x represents an integer of 1 or more and 4 or less. In addition, in the above formula (b7), R 8b represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having from 1 to 6 carbon atoms, or a linear or branched alkoxy group having from 1 to 6 carbon atoms, and y represents an integer of from 1 to 3. Among these, trifluoromethanesulfonate and perfluorobutanesulfonate are preferred from the viewpoint of safety.

[0130] The anion moiety may also contain nitrogen and be represented by the following formulae (b9) and (b10).

[0131] [ka]

[0132] In the above formulas (b9) and (b10), X b represents a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, and most preferably 3 carbon atoms. b , Z b each independently represents a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 or more and 10 or less carbon atoms, preferably 1 or more and 7 or less, and more preferably 1 or more and 3 or less carbon atoms.

[0133] X b The number of carbon atoms in the alkylene group, or Y a , Z a The smaller the number of carbon atoms in the alkyl group, the better the solubility in organic solvents, and therefore the more preferable.

[0134] Also, X bor an alkylene group of Y b , Z b In the alkyl group, the more hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The ratio of fluorine atoms in the alkylene group or alkyl group, i.e., the fluorination rate, is preferably 70% or more and 100% or less, more preferably 90% or more and 100% or less, and most preferably a perfluoroalkylene group or perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0135] Preferable onium salts having a naphthalene ring in the cation moiety include compounds represented by the following formulae (b11-1), (b11-2) and (b12).

[0136] [ka]

[0137] In the photosensitive resin composition, the photoacid generator (B) may be used alone or in combination of two or more kinds. The content of the photoacid generator (B) in the photosensitive resin composition is 0.5 parts by mass or more and 30 parts by mass or less, preferably 1 part by mass or more and 15 parts by mass or less, and more preferably 2 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the polyhydroxystyrene resin (A). When the content of the photoacid generator (B) is within the above range, a photosensitive resin composition having particularly good photolithography properties is easily obtained.

[0138] <Crosslinking agent (C)> The photosensitive resin composition contains a crosslinking agent (C). The crosslinking agent (C) is not particularly limited as long as it is a compound capable of crosslinking molecular chains of the polyhydroxystyrene resin (A) by reacting with the polyhydroxystyrene resin (A). The crosslinking agent (C) is typically a compound having two or more crosslinkable groups. As the crosslinkable groups, a methylol group, an alkoxymethyl group, an acyloxymethyl group, an epoxy group, and an oxetanyl group are preferred.

[0139] From the viewpoint of the refractive index of the cured product formed by using the photosensitive resin composition, the crosslinking agent (C) preferably contains a hetero compound having a crosslinkable group. Examples of the heteroatom contained in the heterocyclic ring of the heterocyclic compound include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a phosphorus atom. Among these heteroatoms, a nitrogen atom is preferred from the viewpoint of the refractive index of the cured product. That is, the heterocyclic compound as the crosslinking agent (C) is preferably a nitrogen-containing heterocyclic compound. The nitrogen-containing heterocyclic compound as the crosslinking agent (C) preferably has a 1,3,5-triazine-2,4,6-triyl group or a 1,3,5-triazine-2,4,6-trione-1,3,5-triyl group, and more preferably has a 1,3,5-triazine-2,4,6-trione-1,3,5-triyl group, from the viewpoint of the high refractive index of the cured product.

[0140] Examples of the crosslinking agent (C) that is preferable in terms of crosslinking reactivity and availability include a methylol-type crosslinking agent (C1) and a polyfunctional epoxy compound (C2). The methylol-type crosslinking agent (C1) and the polyfunctional epoxy compound (C2) will be described below.

[0141] [Methylol-type crosslinking agent (C1)] The methylol crosslinking agent (C1) is a compound having, in the molecule, two or more groups selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. The alkoxy group in the alkoxymethyl group and the acyl group in the acyloxymethyl group may be substituted with a halogen atom. The methylol-type crosslinking agent (C1) is preferably a compound having two or more groups selected from a methylol group and an alkoxymethyl group. When the photosensitive resin composition contains a methylol-type crosslinking agent (C1), the polyhydroxystyrene resin (A) is crosslinked by the methylol-type crosslinking agent (C1) by heating the photosensitive resin composition, and as a result, a cured product having excellent chemical resistance is formed. In addition, the coating film made of the photosensitive resin composition is patterned by exposure and development, and then the patterned coating film is heated to crosslink the polyhydroxystyrene resin (A) with the methylol-type crosslinking agent, thereby forming a microlens having excellent chemical resistance.

[0142] In terms of the chemical resistance of the cured product obtained by heating the photosensitive resin composition, the number of groups selected from methylol groups and alkoxymethyl groups in one molecule of the methylol crosslinking agent (C) is preferably 2 or more and 10 or less, more preferably 2 or more and 8 or less, and even more preferably 2 or more and 4 or less.

[0143] The number of carbon atoms in the alkoxy group in the alkoxymethyl group is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 3, particularly preferably 1 or 2, and most preferably 1. In other words, the most preferable alkoxymethyl group is a methoxymethyl group. The alkoxy group in the alkoxymethyl group may be linear or branched, and is preferably linear.

[0144] The acyloxy group in the acyloxymethyl group is not particularly limited as long as it is a group represented by R-CO-O-. R is an organic group. R is bonded to a carbonyl group by a CC bond. The organic group represented by R is preferably an alkyl group or an aryl group, more preferably an alkyl group. The number of carbon source atoms in the organic group represented by R is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6.

[0145] Suitable examples of the methylol-type crosslinking agent (C1) include methylol melamine compounds, methylol guanamine compounds, methylol urea compounds, resol resins, and aromatic compounds having a methylol group or an alkoxymethyl group on the aromatic ring. Among these, methylolmelamine compounds, methylolguanamine compounds, methylolurea compounds, and aromatic compounds having a methylol group or an alkoxymethyl group on the aromatic ring are preferred.

[0146] Examples of aromatic compounds having a methylol group or an alkoxymethyl group on an aromatic ring include the compounds described in paragraphs

[0136] to

[0139] of JP2013-064829A and the compounds described in paragraphs

[0029] to

[0036] of JP10-0120940A.

[0147] As the methylol-type crosslinking agent (C1), a compound having a methylol group bonded to a nitrogen atom or an alkoxymethyl group bonded to a nitrogen atom is particularly preferred. As the methylol type crosslinking agent (C1) having a methylol group bonded to a nitrogen atom or an alkoxymethyl group bonded to a nitrogen atom, a methylol melamine compound, a methylol guanamine compound, and a methylol urea compound are preferred, a methylol melamine compound and a methylol urea compound are more preferred, and a methylol melamine compound is even more preferred.

[0148] The methylolmelamine compound is preferably a compound represented by the following formula (C1). [ka]

[0149] In formula (C1), R c11 ~R c16 each independently represents a hydrogen atom or -CH 2 -OR c R is a group represented by the formula: c is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. c11 ~R c16 At least two of -CH 2 -OR c It is a group represented by the following formula:

[0150] R c The alkyl group as R may be linear or branched, and is preferably linear. cThe alkyl group as has 1 or more and 6 or less carbon atoms, preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, further preferably 1 or 2, and particularly preferably 1.

[0151] In formula (C1), R c11 ~R c16 Of -CH 2 -OR c The number of groups represented by the following formula (I) is preferably 4 or more and 6, more preferably 5 or 6, and even more preferably 6.

[0152] The methylolguanamine compound is preferably a compound represented by the following formula (C2). [ka]

[0153] In formula (C2), R c21 R is a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. c22 ~R c25 each independently represents a hydrogen atom or -CH 2 -OR c R is a group represented by the formula: c22 ~R c25 At least two of -CH 2 -OR c It is a group represented by the following formula:

[0154] R c21 The alkyl group as R may be linear or branched, and is preferably linear. c21 The number of carbon atoms in the alkyl group as is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, even more preferably 1 or more and 3 or less, still more preferably 1 or 2, and particularly preferably 1. R c21 The cycloalkyl group as the alkyl group preferably has 3 or more and 10 or less, more preferably has 3 or more and 8 or less, further preferably has 4 or more and 7 or less, and particularly preferably has 5 or 6 carbon atoms. R c21The number of carbon atoms in the aryl group as is preferably 6 or more and 14 or less, and more preferably 6 or more and 10 or less. The aryl group is preferably a phenyl group. R c21 As the alkyl group, a hydrogen atom, a methyl group, and a phenyl group are preferable, a hydrogen atom and a phenyl group are more preferable, and a phenyl group is further preferable.

[0155] In formula (C2), R c22 ~R c25 Of -CH 2 -OR c The number of groups represented by the following formula (I) is preferably 2 or more and 4 or less, more preferably 3 or 4, and even more preferably 4.

[0156] The methylol urea compound is preferably a compound represented by the following formula (C3). [ka]

[0157] In formula (C3), R c31 , and R c33 are each independently a hydrogen atom, an alkyl group, or a cycloalkyl group. c32 , and R c34 -CH 2 -OR c R is a group represented by the formula: c31 , and R c33 may be bonded to each other to form a ring. c31 , and R c33 The ring formed by bonding may have other rings condensed thereto. c31 , and R c33 Compounds containing a ring formed by bonding may be condensed with each other.

[0158] R c31 , also R c33 The alkyl group as R may be linear or branched, and is preferably linear. c31 , also R c33The number of carbon atoms in the alkyl group as the radical is preferably 1 or more and 8 or less, more preferably 1 or more and 6 or less, and even more preferably 1 or more and 4 or less. R c31 , also R c33 The cycloalkyl group as the alkyl group preferably has 3 or more and 10 or less, more preferably has 3 or more and 8 or less, further preferably has 4 or more and 7 or less, and particularly preferably has 5 or 6 carbon atoms.

[0159] In formula (C3), R c31 , and R c33 R are preferably both hydrogen atoms or are bonded to each other to form a ring. c31 , and R c33 When forms a ring, the compound represented by formula (C3) is preferably a compound represented by the following formula (C4) or the following formula (C5): The compound represented by the following formula (C5) is also called a methylol glycol uril compound. [ka]

[0160] In formula (C4), R c41 , and R c42 is -CH 2 -OR c R is a group represented by the formula: c43 , and R c44 is a hydrogen atom or a monovalent organic group. L is a single bond or a divalent linking group.

[0161] In formula (C4), R c41 , and R c42 are preferably both methoxymethyl groups.

[0162] In formula (C4), R c43 , and R c44is preferably a monovalent organic group. The monovalent organic group is not particularly limited. As the monovalent organic group, an alkyl group and an alkoxy group are preferable, and an alkoxy group is more preferable. The number of carbon atoms of the alkyl group and the alkoxy group is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, even more preferably 1 or more and 3 or less, particularly preferably 1 or 2, and most preferably 1.

[0163] In formula (C4), L is preferably a single bond. The divalent linking group represented by L is preferably an alkylene group. The alkylene group may be interrupted by an oxygen atom, a carbonyl group, or a carboxylate bond.

[0164] In formula (C5), R c51 ~R c54 is a hydrogen atom or -CH 2 -OR c R is a group represented by the formula: c51 ~R c54 At least two of the are -CH 2 -OR c R is a group represented by the formula: c51 ~R c54 -CH as 2 -OR c The number of groups represented by the following formula (I) is preferably 3 or 4, and more preferably 4.

[0165] Specific preferred examples of the methylol-type crosslinking agent (C1) described above include the following compounds. [ka]

[0166] [ka]

[0167] [ka]

[0168] As the methylol type crosslinking agent (C1), a commercially available product can be used. Specific examples of commercially available products include Nikalac MX-270, Nikalac MW-100LM, Nikalac MX-280, and Nikalac MX-290 (all manufactured by Sanwa Chemical Co., Ltd.).

[0169] The methylol-type crosslinking agent (C1) may be used alone or in combination of two or more kinds.

[0170] [Multifunctional epoxy compound (C2)] Examples of the polyfunctional epoxy compound (C2) include bifunctional epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AD ​​type epoxy resins, naphthalene type epoxy resins, and biphenyl type epoxy resins; glycidyl ester type epoxy resins such as dimer acid glycidyl ester and triglycidyl ester; glycidyl amine type epoxy resins such as tetraglycidylaminodiphenylmethane, triglycidyl-p-aminophenol, tetraglycidylmeta-xylylenediamine, and tetraglycidylbisaminomethylcyclohexane; heterocyclic epoxy resins such as triglycidyl isocyanurate; phloroglucinol triglycidyl ether, trihydroxybiphenyl triglycidyl ether, trihydric trifunctional epoxy resins such as 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-(2,3-epoxypropoxy)phenyl]ethyl]phenyl]propane, and 1,3-bis[4-[1-[4-(2,3-epoxypropoxy)phenyl]-1-[4-[1-[4-(2,3-epoxypropoxy)phenyl]-1-methylethyl]phenyl]ethyl]phenoxy]-2-propanol; and tetrafunctional epoxy resins such as pentaerythritol tetraglycidyl ether, tetrahydroxyphenylethane tetraglycidyl ether, tetraglycidyl benzophenone, bisresorcinol tetraglycidyl ether, and tetraglycidoxybiphenyl.

[0171] Among the above polyfunctional epoxy compounds, the compound represented by the following formula (c1-I) is preferred. [ka]

[0172] In formula (c1-I), X c1 , X c2 , and X c3 each independently represents a hydrogen atom or an organic group which may contain an epoxy group; c1 , X c2 , and X c3 The total number of epoxy groups contained in the epoxy resin is 2 or more.

[0173] As the compound represented by the above formula (c1-I), a compound represented by the following formula (a1-II) is preferable. [ka]

[0174] In formula (c1-II), R c1 ~R c3 represents a linear, branched or cyclic alkylene group, an arylene group, -O-, -C(=O)-, -NH-, or a group consisting of a combination thereof, and may be the same or different. E 1 ~E 3 is an epoxy group or a hydrogen atom. 1 ~E 3 At least two of the groups are epoxy groups.

[0175] In formula (c1-II), R c1 and E 1 , R c2 and E 2 , and R c3 and E 3For example, at least two of the groups represented by the formula (c1-IIa) are preferably groups represented by the following formula (c1-IIa), and all of them are preferably groups represented by the following formula (c1-IIa). It is preferable that the multiple groups represented by the formula (c1-IIa) bonded to one compound are the same group. -LC c (c1-IIa) In formula (c1-IIa), L represents a linear, branched, or cyclic alkylene group, an arylene group, -O-, -C(=O)-, -NH-, or a group formed from a combination thereof; a In formula (c1-IIa), L and C are epoxy groups. a may be bonded to form a cyclic structure.)

[0176] In formula (c1-IIa), the linear, branched or cyclic alkylene group represented by L is preferably an alkylene group having 1 to 10 carbon atoms, and the arylene group represented by L is preferably an arylene group having 5 to 10 carbon atoms. In formula (a1-IIa), L is preferably a linear alkylene group having 1 to 3 carbon atoms, a phenylene group, -O-, -C(=O)-, -NH-, or a group consisting of a combination thereof, and is preferably at least one of a linear alkylene group having 1 to 3 carbon atoms, such as a methylene group, and a phenylene group, or a group consisting of a combination of these with at least one of -O-, -C(=O)-, and NH-.

[0177] In formula (c1-IIa), L and C a Examples of a ring structure formed by bonding with a branched alkylene group and an epoxy group include organic groups represented by the following formulas (c1-IIb) to (c1-IId) when a ring structure (a structure having an epoxy group with an alicyclic structure) is formed by bonding with a branched alkylene group and an epoxy group. [ka]

[0178] In formula (c1-IIb), R c4is a hydrogen atom or a methyl group.

[0179] Examples of the compound represented by formula (c1-II) include, but are not limited to, epoxy compounds having an oxiranyl group or an alicyclic epoxy group. [ka]

[0180] [ka]

[0181] The content of the crosslinking agent (C) in the photosensitive resin composition is not particularly limited as long as the desired effect is not impaired. The content of the crosslinking agent (C) in the photosensitive resin composition is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 2 parts by mass or more and 25 parts by mass or less, and particularly preferably 5 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the polyhydroxystyrene resin (A).

[0182] <Quencher (D)> The photosensitive resin composition may contain a quencher (D). As the quencher (D), a low molecular weight compound (non-polymer) is usually used. As the quencher (D), for example, an amine such as an aliphatic amine or an aromatic amine can be mentioned. As the quencher (D), an aliphatic amine is preferable, and a secondary aliphatic amine and a tertiary aliphatic amine are particularly preferable. Here, the aliphatic amine is an amine having one or more aliphatic groups. The number of carbon atoms of the aliphatic group of the aliphatic amine is preferably 1 or more and 20 or less.

[0183] Examples of aliphatic amines include ammonia (NH 3 ), alkylamines in which at least one hydrogen atom is substituted with an alkyl group having 20 or less carbon atoms, ammonia (NH 3 ) alkanolamines in which at least one hydrogen atom is substituted with a hydroxyalkyl group, and cyclic amines.

[0184] Specific examples of alkylamines and alkanolamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkanolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, stearyldiethanolamine, and lauryldiethanolamine. Of these, trialkylamines and alkanolamines are preferred.

[0185] Examples of the cyclic amine include nitrogen-containing heterocyclic compounds. The nitrogen-containing heterocyclic compounds may be monocyclic aliphatic amines or polycyclic aliphatic amines.

[0186] Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The number of carbon atoms of the aliphatic polycyclic amine is preferably 6 or more and 10 or less. Specific examples of the aliphatic polycyclic amine include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0187] Specific examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, and tris[2-{2-(2-hydroxyethoxy)ethoxy}ethylamine].

[0188] Specific examples of aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, 2,2'-dipyridyl, and 4,4'-dipyridyl.

[0189] The quencher (D) may be used alone or in combination of two or more kinds. The amount of the quencher (D) contained in the photosensitive resin composition is preferably 0.01 parts by mass or more and 5.0 parts by mass or less based on 100 parts by mass of the polyhydroxystyrene resin (A).

[0190] <Organic solvent (S)> The photosensitive resin composition may contain an organic solvent (S). When the photosensitive resin composition contains an organic solvent (S), it is easy to adjust the coating property of the photosensitive resin composition and the film thickness of the positive photosensitive resin composition layer formed using the photosensitive resin composition. The organic solvent (S) may be used alone or in combination of two or more kinds.

[0191] Specific examples of the organic solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and dipropylene glycol monoacetate, as well as monomethyl ethers thereof (e.g., propylene glycol monomethyl ether acetate), monoethyl ether, monopropyl ether, monobutyl ether, and monophenyl ether; and derivatives thereof; cyclic ethers such as dioxane; esters such as ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyethyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, and 3-methyl-3-methoxybutyl acetate; and aromatic hydrocarbons such as toluene and xylene.

[0192] In the photosensitive resin composition, the content of the organic solvent (S) is preferably 50 parts by mass or more and 3000 parts by mass or less, and more preferably 100 parts by mass or more and 2000 parts by mass or less, relative to 100 parts by mass of the polyhydroxystyrene resin (A). When the content is within the above range, the coatability of the photosensitive resin composition is likely to be improved, and the thickness of the coating film formed using the photosensitive resin composition is easily adjusted.

[0193] <Other ingredients> The photosensitive resin composition may contain various additives in addition to the above components, as long as the desired effect is not impaired. The additives may be appropriately selected from various additives that have been conventionally blended into photosensitive resin compositions. Specific examples of other components include polyvinyl resins, surfactants, and acids or acid anhydrides.

[0194] The photosensitive resin composition may contain a polyvinyl resin in order to improve the plasticity of the coating film formed. Specific examples of the polyvinyl resin include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoic acid, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylphenol, and copolymers thereof.

[0195] The photosensitive resin composition may contain an adhesion aid in order to improve adhesion to a support.

[0196] The photosensitive resin composition may contain a surfactant to improve coating properties, defoaming properties, leveling properties, etc. Specific examples of surfactants include BM-1000, BM-1100 (all manufactured by BM Chemie), Megafac F142D, Megafac F172, Megafac F173, Megafac F183 (all manufactured by DIC Corporation), Fluorad FC-135, Fluorad FC-170C, Fluorad FC-430, Fluorad FC-431 (all manufactured by Sumitomo 3M Limited), Surflon S-112, Surflon S-113, Surflon Examples of commercially available fluorine-based surfactants include, but are not limited to, commercially available fluorine-based surfactants such as S-131, Surflon S-141, Surflon S-145 (all manufactured by Asahi Glass Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (all manufactured by Toray Silicones Co., Ltd.), Polyfox PF-136A, Polyfox PF-156A, Polyfox PF-151N, Polyfox PF-636, Polyfox PF-656, Polyfox PF-6520 (all manufactured by OMNOVA Solutions).

[0197] The photosensitive resin composition may contain an acid or an acid anhydride in order to finely adjust the solubility in the developer.

[0198] Specific examples of acids and acid anhydrides include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, and cinnamic acid; hydroxymonocarboxylic acids such as lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid, and syringic acid; oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, butanetetracarboxylic acid, and trimellitic acid. Examples of the acid anhydride include polyvalent carboxylic acids such as itaconic anhydride, pyromellitic anhydride, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, and 1,2,5,8-naphthalenetetracarboxylic acid; and acid anhydrides such as itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenylsuccinic anhydride, tricarbanilic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, himic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bistrimellitate anhydride, and glycerin tristrimellitate anhydride.

[0199] <Method for producing photosensitive resin composition> The photosensitive resin composition can be prepared by mixing and stirring the above-mentioned components by a conventional method. If necessary, dispersion and mixing may be performed using a dispersing machine such as a dissolver, homogenizer, or three-roll mill. After mixing, the components may be filtered using a mesh, membrane filter, or the like.

[0200] ≪Cured product≫ By heating the photosensitive resin composition, the polyhydroxystyrene resin (A) is crosslinked with the crosslinking agent (C) to form a cured product. Such a cured product has excellent chemical resistance. The photosensitive resin composition may be exposed to light before being cured by heating. In this case, the acid generated by the photoacid generator (B) upon exposure promotes the reaction between the polyhydroxystyrene resin (A) and the crosslinking agent (C).

[0201] <Method for manufacturing optical elements> An optical element having a plurality of microlenses on a substrate can be manufactured by the following method. Specifically, this method is Coating the photosensitive resin composition on a substrate to form a coating film; exposing the coating film to light in a selective manner so that a plurality of dots are formed at positions on the substrate where a plurality of microlenses are to be formed; developing the exposed coating film to form a plurality of dots at positions where a plurality of microlenses are to be formed; and heating the plurality of dots to thermally deform the plurality of dots to form a plurality of microlenses. In this method, the dots are exposed to light before they are heated.

[0202] The method of applying the photosensitive resin composition onto the substrate is not particularly limited. For example, the photosensitive resin composition is applied to a desired thickness using a contact transfer type coating device such as a roll coater, a reverse coater, a bar coater, or a slit coater, or a non-contact type coating device such as a spinner (rotary coating device) or a curtain flow coater to form a coating film.

[0203] The formed coating film may be appropriately subjected to a heat treatment (pre-bake (post-apply bake (PAB)) treatment) to remove the solvent in the coating film. The conditions of the heat treatment vary depending on the types of components of the photosensitive resin composition, the blending ratio, the coating film thickness, etc. The heating temperature is, for example, preferably 60° C. to 150° C., and more preferably 70° C. to 140° C. The heating time is, for example, preferably 0.5 minutes to 60 minutes, and more preferably 1 minute to 50 minutes. The thickness of the coating film is appropriately selected depending on the size of the microlens to be formed. The thickness of the coating film is preferably in the range of 100 nm or more and 50 μm or less, and more preferably in the range of 400 nm or more and 30 μm or less.

[0204] Next, the coating film is subjected to position-selective exposure so that a plurality of dots are formed at positions on the base material where a plurality of microlenses are to be formed.

[0205] The position-selective exposure can be carried out, for example, through a desired mask pattern. The wavelength of the light used for exposure is not particularly limited. The exposure can be carried out using radiation such as KrF excimer laser, ArF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, and soft X-ray.

[0206] After the exposure, the coating film is subjected to a PEB (post-exposure bake) treatment (post-exposure baking) as necessary. The conditions of the PEB treatment vary depending on the type and blending ratio of each component in the first coating film, the coating film thickness, etc. For example, the heating temperature is preferably 60°C or more and 150°C or less, more preferably 70°C or more and 140°C or less. The heating time is preferably, for example, 0.5 minutes or more and 60 minutes or less, more preferably 1 minute or more and 50 minutes or less.

[0207] Next, the coating film is developed, whereby unnecessary portions are dissolved and removed, and a plurality of dots are formed in the positions where a plurality of microlenses are to be formed.

[0208] As the developer, for example, an aqueous solution of an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane, etc. can be used. In addition, an aqueous solution of the above-mentioned alkalis with an appropriate amount of water-soluble organic solvent such as methanol or ethanol or a surfactant can be used as the developer. As the developer, an aqueous solution of tetramethylammonium hydroxide having a concentration of 0.1% by mass or more and 10% by mass or less is preferable.

[0209] The developing time varies depending on the composition of the photosensitive resin composition, the thickness of the coating film, etc., but is usually from 1 minute to 30 minutes. The developing method may be any of a puddle method, a dipping method, a puddle method, a spray developing method, etc.

[0210] The developed coating film is washed with running water or the like as necessary, and then dried. In this manner, a plurality of dots are formed at the positions where a plurality of microlenses are to be formed.

[0211] Next, the dots are heated to deform the dots by heat to form microlenses. As the dots deform, the polyhydroxystyrene resin (A) contained in each dot is crosslinked by the crosslinking agent (C) to form microlenses with excellent chemical resistance. Before the dots are heated, the dots are exposed to light. The exposure is performed in the same manner as described above. The acid generated by the photoacid generator (B) upon exposure promotes crosslinking between the polyhydroxystyrene resin (A) and the crosslinking agent (C).

[0212] The heating conditions vary depending on the types of components in the photosensitive resin composition, the blending ratio, the coating film thickness, etc. For example, the heating temperature is preferably 170° C. or more and 250° C. or less, and more preferably 180° C. or more and 230° C. or less. The heating time is preferably, for example, 1 minute or more and 30 minutes or less, and more preferably 3 minutes or more and 10 minutes or less.

[0213] In this manner, an optical element including a plurality of microlenses is formed on the substrate.

[0214] As described above, the present inventors provide the following (1) to (8). (1) A photosensitive resin composition comprising a polyhydroxystyrene resin (A), a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation, and a crosslinking agent (C), In the polyhydrostyrene resin (A), a part of the phenolic hydroxyl groups is protected by an acetal-type protecting group, A photosensitive resin composition which gives a cured product having a refractive index of 1.50 or more at a wavelength of 550 nm. (2) The photosensitive resin composition according to (1), wherein the crosslinking agent (C) contains a heterocyclic compound having a crosslinkable group. (3) The photosensitive resin composition according to (2), wherein the heterocyclic compound is a nitrogen-containing heterocyclic compound. (4) The photosensitive resin composition according to (3), wherein the nitrogen-containing heterocyclic compound has a 1,3,5-triazine-2,4,6-trione-1,3,5-triyl group. (5) The photosensitive resin composition according to any one of (1) to (4), wherein the photoacid generator (B) comprises a sulfonate-type photoacid generator (B1) and / or an onium salt-type photoacid generator (B2). (6) A cured product of the photosensitive resin composition according to any one of (1) to (4). (7) A microlens made of the cured product according to (6). (8) A method for manufacturing an optical element having a plurality of microlenses on a substrate, comprising the steps of: Coating a substrate with the photosensitive resin composition according to any one of (1) to (4) to form a coating film; exposing the coating film to light in a selective manner so that a plurality of dots are formed at positions on the substrate where a plurality of microlenses are to be formed; developing the exposed coating film to form a plurality of dots at positions where a plurality of microlenses are to be formed; and heating the plurality of dots to thermally deform the plurality of dots to form a plurality of microlenses; A manufacturing method in which the plurality of dots are exposed to light prior to heating the plurality of dots. EXAMPLES

[0215] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0216] [Examples 1 to 5, and Comparative Example 1] In the examples and comparative examples, A-1 consisting of the following units was used as the polyhydroxystyrene resin (A). In each of the following formulas, the number attached to each repeating unit is the ratio (mol %) of each unit to all units contained in resin (A). The weight average molecular weight (Mw) of resin A-1 measured by gel permeation chromatography in terms of polystyrene is 20,000.

[0217] [ka]

[0218] In the examples and comparative examples, the following B1 to B3 were used as the photoacid generator (B). [ka]

[0219] In the examples and comparative examples, the following C1 to C3 were used as the crosslinking agent (C). [ka]

[0220] Resin (A) of the type shown in Table 1, photoacid generator (B) of the type shown in Table 1, crosslinker (C) of the type shown in Table 1, salicylic acid (SA), tri-n-pentylamine (TPA), and surfactant (BYK-310, manufactured by BYK-Chemie) were dissolved in propylene glycol monomethyl ether acetate (PM) to give the compositions shown in Table 1, to obtain photosensitive resin compositions for each of the Examples and Comparative Examples. Propylene glycol monomethyl ether acetate (PM) was used in an amount such that the solid content concentration of the photosensitive resin composition was 50 mass %. In Comparative Example 1, the crosslinking agent (C) was not used.

[0221] The obtained photosensitive resin composition was used to evaluate the chemical resistance, refractive index, and transmittance of the cured film, and the patterning characteristics (pattern shape) of the photosensitive resin composition according to the following methods. The evaluation results are shown in Table 1.

[0222] <Chemical resistance> The photosensitive resin composition of each Example and Comparative Example was applied onto a silicon substrate using a spin coater. The photosensitive resin composition applied onto the silicon substrate was baked at 100° C. for 180 seconds to obtain a coating film having a thickness of about 20 μm. The obtained coating film was immersed three times in an aqueous solution of tetramethylammonium hydroxide having a concentration of 2.38% by mass for 60 seconds. After immersion, the coating film was rinsed with pure water and dried, and then the coating film was exposed to light using a ghi-line exposure machine at a dose of 999 mJ / cm. 2 The exposed coating film was baked at 200° C. for 5 minutes to obtain a cured film. The formed cured film was immersed in acetone or propylene glycol monomethyl ether acetate (PM) at 25° C. for 5 minutes. The film thickness variation rate was calculated from the film thickness T1 before immersion and the film thickness T2 after immersion according to the following formula. Film thickness variation rate (%) = │100-(T2 / T1×100)│ Based on the calculated film thickness variation rate, the chemical resistance was evaluated according to the following criteria. A: The film thickness variation rate was 1% or less. B: The film thickness variation rate was more than 1% and 3% or less. C: The film thickness variation rate was more than 3%.

[0223] <Refractive index and transmittance> A cured film having a thickness of 1 μm was formed in the same manner as in the evaluation method for chemical resistance, and the refractive index at a light wavelength of 550 nm was evaluated using a spectroscopic ellipsometer M-2000 manufactured by JA Woollam. In addition, the light transmittance of the cured film formed in the same manner as in the transmittance evaluation method was determined by measuring the light transmittance using a measuring device under the trade name "MCPD-3000" manufactured by Otsuka Electronics Co., Ltd. The light transmittance is a value at a light wavelength of 380 nm to 780 nm.

[0224] <Patterning characteristic evaluation (pattern shape)> The photosensitive resin composition of each Example and Comparative Example was applied onto a silicon substrate using a spin coater. The photosensitive resin composition applied onto the silicon substrate was baked at 100° C. for 180 seconds to obtain a coating film having a thickness of about 20 μm. The obtained coating film was exposed to light using an i-line exposure machine under the condition of NA / σ=0.18 / 0.75 through a mask to form a dot pattern in which rectangular dots of 40 μm × 40 μm were arranged with rectangular grooves (spaces) spaced 40 μm apart from each other. The exposed coating film was developed by immersing it in an aqueous solution of tetramethylammonium hydroxide having a concentration of 2.38% by mass for 60 seconds three times to form a dot pattern. The resulting dot pattern was rinsed with pure water and dried, and then the dot pattern was exposed to light using a ghi ray exposure machine at an exposure dose of 999 mJ / cm. 2 The exposure was performed at . The exposed dot pattern was baked at 200° C. for 5 minutes to cause thermal flow, thereby obtaining a microlens pattern composed of microlenses made of a cured product of the photosensitive resin composition. The formed microlens pattern was observed with a microscope from a direction perpendicular to the surface direction of the silicon substrate, and the patterning characteristics (pattern shape) were evaluated according to the following criteria. A: The dots were transformed into a good lens shape with a diameter of 44 μm or less. B: The dot was deformed into a lens shape having a diameter of more than 44 μm and not more than 48 μm. C: After development, a dot pattern could not be formed or the dots were deformed such that the diameter after deformation was more than 48 μm.

[0225] [Table 1]

[0226] From Examples 1 to 5, it can be seen that in a photosensitive resin composition containing a polyhydroxystyrene resin (A), a photoacid generator (B), and a crosslinking agent (C), by using a polyhydroxystyrene resin (A) in which some of the phenolic hydroxyl groups are protected with acetal-type protecting groups, it is possible to form a microlens having excellent chemical resistance using the photosensitive resin composition.

Claims

1. A photosensitive resin composition comprising: a polyhydroxystyrene resin (A); a photoacid generator (B) that generates an acid upon exposure to actinic rays or radiation; and a crosslinking agent (C), In the polyhydrostyrene resin (A), a part of the phenolic hydroxyl groups is protected by an acetal-type protecting group, The photosensitive resin composition provides a cured product having a refractive index of 1.50 or more at a wavelength of 550 nm.

2. The photosensitive resin composition according to claim 1 , wherein the crosslinking agent (C) comprises a heterocyclic compound having a crosslinkable group.

3. The photosensitive resin composition according to claim 2 , wherein the heterocyclic compound is a nitrogen-containing heterocyclic compound.

4. The photosensitive resin composition according to claim 3, wherein the nitrogen-containing heterocyclic compound has a 1,3,5-triazine-2,4,6-trione-1,3,5-triyl group.

5. The photosensitive resin composition according to claim 1 or 2, wherein the photoacid generator (B) comprises a sulfonate-type photoacid generator (B1) and / or an onium salt-type photoacid generator (B2).

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

7. A microlens comprising the cured product according to claim 6.

8. A method for manufacturing an optical element having a plurality of microlenses on a substrate, comprising the steps of: A method for producing a coating film by applying the photosensitive resin composition according to claim 1 or 2 onto a substrate; exposing the coating film to a position-selective exposure so that a plurality of dots are formed at positions on the substrate where the plurality of microlenses are to be formed; developing the exposed coating film to form the dots at positions where the microlenses are to be formed; and heating the dots to thermally deform the dots to form the microlenses. A method of manufacturing wherein the plurality of dots is exposed to light prior to heating the plurality of dots.

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