Photosensitive resin composition, and method for producing micro-lens

Abstract

To provide a photosensitive resin composition capable of forming a micro-lens pattern fine and high in etching rate as a mask layer for dry etching by using a KrF excimer laser or an ArF excimer laser, and a method for producing a micro-lens.SOLUTION: A photosensitive resin composition used for forming a micro-lens pattern on a lens material layer as a mask layer for dry etching contains a resin (A), an optical acid-generating agent (B), and a solvent (S), where the resin (A) has a constitutional unit (a1) derived from a (meth)acrylic acid ester, including an acid-dissociable dissolution-inhibiting group, and having increased solubility to an alkali by an action of an acid, and a constitutional unit (a2) including a residue suppression group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a photosensitive resin composition and a method for manufacturing a microlens.

Background Art

[0002] Conventionally, solid-state imaging devices have been used in cameras, video cameras, and the like. For such solid-state imaging devices, a CCD (charge-coupled device) image sensor or a CMOS (complementary metal-oxide semiconductor) image sensor is used. The image sensor is provided with a fine condenser lens (hereinafter referred to as a microlens) for the purpose of improving the light collection rate.

[0003] When forming such a microlens, roughly speaking, a method called a thermal flow method and a method called an etching method are widely adopted industrially. In the former thermal flow method, a photoresist film (a layer composed of a positive photosensitive resin composition or the like) is formed on the upper part of a CCD element or the like, and then exposure and development are sequentially performed to form an uneven pattern on the element. By heating this uneven pattern at a temperature above the glass transition point to make it flow, a hemispherical microlens pattern is formed by surface tension (For example, refer to Patent Document 1). On the other hand, in the latter etching method, after forming a positive photosensitive resin composition layer on a lens material layer using a positive photosensitive resin composition, this is selectively exposed. Next, after removing the exposed portion by development, the positive photosensitive resin composition layer is fluidized by heat treatment to form a mask layer having a microlens pattern. Then, the lens material layer and the mask layer are dry-etched to transfer the shape of the microlens pattern to the lens material layer, thereby obtaining a microlens.

Prior Art Documents

Patent Documents

[0004] Patent Document 1 Japanese Patent Application Laid-Open No. 2009-20462 Summary of the Invention Problems to be Solved by the Invention

[0005] By the way, in recent years, CCD image sensors and CMOS image sensors have tended to have higher definition. Therefore, as the photosensitive resin composition, it is required to be able to form a fine microlens pattern. In addition, with the increase in the definition of image sensors, the wavelength of light irradiated on the photosensitive resin composition has also become shorter. More specifically, it has been proposed to gradually shift from the exposure conditions using i-line (wavelength 365 nm), which has been widely used conventionally, to the exposure conditions using KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm).

[0006] Furthermore, in the etching method, when using a lens material layer with a high etching rate, in order to transfer the microlens pattern shape well, it is required to be able to form a microlens pattern with a high etching rate in accordance with the lens material layer.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a photosensitive resin composition capable of forming a fine microlens pattern with a high etching rate as a mask layer for dry etching using a KrF excimer laser or an ArF excimer laser, and a method for manufacturing a microlens. Means for Solving the Problems

[0008] In order to solve the above problems, as a result of intensive studies by the present inventors, it has been found that the above problems can be solved by a photosensitive resin composition containing a resin having a specific structural unit, a photoacid generator, and a solvent, and the present invention has been completed. Specifically, the present invention provides the following.

[0009] [1] A photosensitive resin composition used for forming a microlens pattern as a mask layer for dry etching on a lens material layer, wherein the photosensitive resin composition contains a resin (A), a photoacid generator (B), and a solvent (S), the resin (A) is derived from (meth)acrylic acid ester, contains an acid-dissociable dissolution-inhibiting group, and has a structural unit (a1) in which the solubility in alkali increases by the action of an acid, and a structural unit (a2) containing a residue-inhibiting group, the photosensitive resin composition.

[0010] [2] The structural unit (a1) is a structural unit represented by any one of the following formulas (a1-1) to (a1-3), the photosensitive resin composition according to [1]. [Chemical formula] (In formulas (a1-1) to (a1-3), R 14b , and R 18b to R 23b each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, or a linear or branched fluorinated alkyl group having 1 to 6 carbon atoms, R 15b to R 17b each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched fluorinated alkyl group having 1 to 6 carbon atoms, or an aliphatic cyclic group having 5 to 20 carbon atoms, R 16b and R 17b may be bonded to each other to form a hydrocarbon ring having 5 to 20 carbon atoms together with the carbon atom to which both are bonded, Y b represents an aliphatic cyclic group or an alkyl group which may have a substituent, p represents an integer of 0 or more and 4 or less, and q represents 0 or 1.)

[0011] [3] The residue-inhibiting group is a lactone-containing cyclic group or a -SO 2 -containing cyclic group, the photosensitive resin composition according to [1] or [2].

[0012] [4] Apply the photosensitive resin composition according to any one of [1] to [3] onto the lens material layer to form a coating film, and selectively expose the coating film, and develop the exposed coating film, and heat the developed coating film to form a mask layer having a microlens pattern, and dry-etch the lens material layer and the mask layer to transfer the shape of the microlens pattern to the lens material layer. A method for manufacturing a microlens, comprising:

[0013] [5] The method for manufacturing a microlens according to [4], wherein the coating film is exposed with a KrF excimer laser or an ArF excimer laser.

Advantages of the Invention

[0014] According to the present invention, there can be provided a photosensitive resin composition capable of forming a fine microlens pattern having a high etching rate as a mask layer for dry etching using a KrF excimer laser or an ArF excimer laser, and a method for manufacturing a microlens.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0016] ≪Photosensitive Resin Composition≫ The photosensitive resin composition is used to form a microlens pattern as a mask layer for dry etching on the lens material layer. The photosensitive resin composition contains a resin (A), a photoacid generator (B), and a solvent (S). The resin (A) is derived from (meth)acrylic acid esters and has a structural unit (a1) containing an acid-dissociable dissolution inhibitory group and increasing solubility in alkali by the action of an acid, and a structural unit (a2) containing a residue inhibitory group.

[0017] <Resin (A)> Resin (A) is derived from a (meth)acrylate ester, contains an acid-dissociable dissolution-inhibiting group, and has a structural unit (a1) that increases solubility in alkali by the action of an acid, and a structural unit (a2) that contains a residue-inhibiting group.

[0018] By using such Resin (A), a fine microlens pattern with a high etching rate as a mask layer for dry etching can be formed by a KrF excimer laser or an ArF excimer laser. In the formation of the microlens pattern of the mask layer, heat treatment is often performed in a set temperature range around 150°C. However, by using Resin (A), a photosensitive resin composition excellent in thermal flowability can be obtained because a microlens pattern can be formed by heat treatment around 150°C.

[0019] [Structural unit (a1)] The structural unit (a1) is not particularly limited as long as it is a structural unit known conventionally as a structural unit derived from a (meth)acrylate ester, contains an acid-dissociable dissolution-inhibiting group, and increases solubility in alkali by the action of an acid.

[0020] As the structural unit (a1), a structural unit represented by any of the following formulas (a1-1) to (a1-3) is preferable.

[0021] [Chemical formula]

[0022] In the above formulas (a1-1) to (a1-3), R 14b , and R 18b ~R 23b each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, or a linear or branched fluorinated alkyl group having 1 to 6 carbon atoms, and R 15b ~R 17beach independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched fluorinated alkyl group having 1 to 6 carbon atoms, or an aliphatic cyclic group having 5 to 20 carbon atoms, and R 16b and R 17b may be bonded to each other to form a hydrocarbon ring having 5 to 20 carbon atoms together with the carbon atom to which both are bonded, and Y b represents an aliphatic cyclic group or an alkyl group which may have a substituent, p represents an integer of 0 to 4, and q represents 0 or 1.

[0023] Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like. The fluorinated alkyl group is a group in which some or all of the hydrogen atoms of the above alkyl group are substituted by fluorine atoms. Specific examples of the aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. Specifically, groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be mentioned. In particular, groups obtained by removing one hydrogen atom from cyclohexane or adamantane (which may further have a substituent) are preferable.

[0024] When the above R 16b and R 17b do not bond to each other to form a hydrocarbon ring, the above R 15b , R 16b , and R 17b are preferably a linear or branched alkyl group having 1 to 4 carbon atoms from the viewpoints of high contrast and good resolution, depth of focus width, etc. The above R 19b , R 20b , R 22b , R 23bis preferably a hydrogen atom or a methyl group.

[0025] The above R 16b and R 17b may together with the carbon atom to which both are attached form an aliphatic cyclic group having 5 to 20 carbon atoms. Specific examples of such aliphatic cyclic groups include groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. Specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be mentioned. In particular, groups obtained by removing one or more hydrogen atoms from cyclopentane, cyclohexane, or adamantane (which may further have substituents) are preferred.

[0026] Furthermore, when the aliphatic cyclic group formed by the above R 16b and R 17b has a substituent on its ring skeleton, examples of such substituents include polar groups such as a hydroxyl group, a carboxy group, a cyano group, and an oxygen atom (=O), and linear or branched alkyl groups having 1 to 4 carbon atoms. As the polar group, an oxygen atom (=O) is particularly preferred.

[0027] The above Y b is an aliphatic cyclic group or an alkyl group, and examples thereof include groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. Specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be mentioned. In particular, groups obtained by removing one or more hydrogen atoms from adamantane (which may further have substituents) are preferred.

[0028] Furthermore, the above Yb When the aliphatic cyclic group has a substituent on its ring skeleton, examples of the substituent include polar groups such as a hydroxyl group, a carboxy group, a cyano group, an oxygen atom (=O), and a linear or branched alkyl group having 1 to 4 carbon atoms. As the polar group, an oxygen atom (=O) is particularly preferable.

[0029] Also, when Y b is an alkyl group, it is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, more preferably 6 to 15 carbon atoms. Such an alkyl group is particularly preferably an alkoxyalkyl group, and examples of such an alkoxyalkyl group 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-methoxypropyl group, a 1-ethoxypropyl group, a 1-methoxy-1-methyl-ethyl group, a 1-ethoxy-1-methylethyl group, and the like.

[0030] Preferable specific examples of the structural unit represented by the above formula (a1-1) include those represented by the following formulas (a1-1-1) to (a1-1-33).

[0031]

Chemical formula

[0032] In the above formulas (a1-1-1) to (a1-1-33), R 24b represents a hydrogen atom or a methyl group.

[0033] Preferable specific examples of the structural unit represented by the above formula (a1-2) include those represented by the following formulas (a1-2-1) to (a1-2-26).

[0034]

Chemical formula

[0035] In the above formulas (a1-2-1) to (a1-2-26), R 24b represents a hydrogen atom or a methyl group.

[0036] Preferable specific examples of the structural unit represented by the above formula (a1-3) include those represented by the following formulas (a1-3-1) to (a1-3-15).

[0037]

Chemical formula

[0038] In the above formulas (a1-3-1) to (a1-3-15), R 24b represents a hydrogen atom or a methyl group.

[0039] Among the structural units represented by the formulas (a1-1) to (a1-3) described above, the structural unit represented by the formula (a1-1) is preferable. Further, among the structural units represented by the formula (a1-1), it is preferable that R 16b and R 17b form an aliphatic cyclic group having 5 to 20 carbon atoms together with the carbon atom to which both are bonded, and it is preferable that R 15b is a linear or branched alkyl group having 1 to 6 carbon atoms. The content ratio of the structural unit (a1) in the resin (A) (when a plurality of types are contained, the total content ratio) is preferably 5% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 55% by mass or less, and particularly preferably 15% by mass or more and 50% by mass or less.

[0040] [Structural unit (a2)] The structural unit (a2) contains a residue suppressing group. The residue suppressing group means a group that suppresses the generation of residues in the developing process. Examples of the residue suppressing group include a lactone-containing cyclic group or a -SO 2 -containing cyclic group. Among them, a lactone-containing cyclic group is preferable.

[0041] (-SO 2 -containing cyclic group) Here, the "-SO 2 -containing cyclic group" refers to a cyclic group containing a ring having -SO 2 - in its ring skeleton, specifically, a cyclic group in which the sulfur atom (S) in -SO 2 - forms part of the ring skeleton of the cyclic group. Counting the ring having -SO 2 - in its ring skeleton as the first ring, if it is only this ring, it is a monocyclic group, and if it further has another ring structure, it is called a polycyclic group regardless of its structure. The -SO 2 -containing cyclic group may be monocyclic or polycyclic.

[0042] -SO 2 -containing cyclic group is particularly preferably a cyclic group containing a ring having -O-SO 2 - in its ring skeleton, that is, a cyclic group containing a sultone ring in which -O-S- in -O-SO 2 - forms part of the ring skeleton.

[0043] -SO 2 -Regarding the number of carbon atoms of the -containing cyclic group, 3 or more and 30 or less is preferable, 4 or more and 20 or less is more preferable, 4 or more and 15 or less is further preferable, and 4 or more and 12 or less is particularly preferable. The number of carbon atoms refers to the number of carbon atoms constituting the ring skeleton and does not include the number of carbon atoms in the substituent.

[0044] -SO 2 -containing cyclic group may be a -SO 2 -containing aliphatic cyclic group or a -SO 2 -containing aromatic cyclic group. Preferably it is a -SO 2 -containing aliphatic cyclic group.

[0045] -SO 2 -As the -containing aliphatic cyclic group, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which a part of the carbon atoms constituting its ring skeleton is substituted with -SO 2 - or -O-SO 2 - is mentioned. More specifically, -CH 2 - constituting its ring skeleton is -SO2 A group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring substituted with -, and -CH that constitutes the ring 2 -CH 2 - is -O-SO 2 Examples include a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring substituted with - and the like.

[0046] The number of carbon atoms of the alicyclic hydrocarbon ring is preferably 3 or more and 20 or less, more preferably 3 or more and 12 or less. The alicyclic hydrocarbon ring may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane having 3 to 6 carbon atoms is preferable. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon ring, a group obtained by removing two hydrogen atoms from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0047] -SO 2 The -containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (=O), -COOR”, -OC(=O)R”, a hydroxyalkyl group, and a cyano group.

[0048] As the alkyl group as the substituent, an alkyl group having 1 to 6 carbon atoms is preferable. The alkyl group is preferably linear or branched. Specifically, examples 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, a neopentyl group, and an n-hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.

[0049] As the alkoxy group as the substituent, an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned as the alkyl group as the aforementioned substituent is bonded to an oxygen atom (-O-) can be mentioned.

[0050] Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferable.

[0051] Examples of the halogenated alkyl group of the substituent include a group in which some or all of the hydrogen atoms of the aforementioned alkyl group are substituted with the aforementioned halogen atoms.

[0052] Examples of the halogenated alkyl group as the substituent include a group in which some or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the aforementioned substituent are substituted with the aforementioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0053] In the aforementioned -COOR” and -OC(=O)R”, each of R” is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.

[0054] When R” is a linear or branched alkyl group, the number of carbon atoms of the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 or 2.

[0055] When “R” is a cyclic alkyl group, the number of carbon atoms of the cyclic alkyl group is preferably 3 or more and 15 or less, more preferably 4 or more and 12 or less, and particularly preferably 5 or more and 10 or less. Specifically, examples include a group obtained by removing one or more hydrogen atoms from a monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. More specifically, examples include a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane and cyclohexane, and a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0056] As the hydroxyalkyl group as the substituent, a hydroxyalkyl group having 1 to 6 carbon atoms is preferable. Specifically, examples include a group in which at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the above-mentioned substituent is substituted with a hydroxyl group.

[0057] -SO 2 As the -containing cyclic group, more specifically, groups represented by the following formulas (a2-11) to (a2-14) can be mentioned.

Chemical formula

[0058] In the above formulas (a2-11) to (a2-14), A’ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom. As the alkylene group having 1 to 5 carbon atoms in A’, a linear or branched alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.

[0059] When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is interposed between the terminal or carbon atoms of the aforementioned alkylene group, for example, -O-CH 2 -、-CH 2 -O-CH 2 -、-S-CH 2 -、-CH 2 -S-CH 2 - and the like. As A’, an alkylene group having 1 to 5 carbon atoms or -O- is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

[0060] z may be any of 0, 1, and 2, and 0 is most preferable. When z is 2, the plurality of R 10b may be the same or different from each other.

[0061] R 10b The alkyl group, alkoxy group, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in are, respectively, the same as those described above for the substituents that the -SO 2 -containing cyclic group may have.

[0062] Specific cyclic groups represented by the above formulas (a2-11) to (a2-14) are exemplified below. In the formulas, “Ac” represents an acetyl group.

[0063] [Chemistry]

[0064] [Chemistry]

[0065] (Lactone-containing cyclic group) The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. Counting the lactone ring as the first ring, if it is only a lactone ring, it is a monocyclic group, and if it further has other ring structures, regardless of its structure, it is called a polycyclic group. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

[0066] As the lactone cyclic group in the structural unit (a2), any group can be used without particular limitation. Specifically, as the lactone-containing monocyclic group, groups obtained by removing one hydrogen atom from 4- to 6-membered lactones, such as groups obtained by removing one hydrogen atom from β-propiolactone, groups obtained by removing one hydrogen atom from γ-butyrolactone, groups obtained by removing one hydrogen atom from δ-valerolactone, etc. can be mentioned. Also, as the lactone-containing polycyclic group, groups obtained by removing one hydrogen atom from bicycloalkanes, tricycloalkanes, and tetracycloalkanes having a lactone ring can be mentioned.

[0067] As the structural unit (a2), as long as it is a -SO 2 -containing cyclic group or a structural unit having a lactone-containing cyclic group, the structure of other parts is not particularly limited, but it is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted by a substituent and contains a -SO 2 -containing cyclic group (a2-S), and at least one structural unit selected from the group consisting of a structural unit (a2-L) derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted by a substituent and contains a lactone-containing cyclic group is preferred, and the structural unit (a2-L) is more preferred.

[0068] [Constituent unit (a2-S)] As an example of the constituent unit (a2-S), more specifically, a constituent unit represented by the following formula (a2-S1) can be mentioned.

[0069] [Chemical formula] (In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R 11b is a -SO 2 -containing cyclic group, and R 12b is a single bond or a divalent linking group.)

[0070] In formula (a2-S1), R is the same as described above. R 11b is the same as the -SO 2 -containing cyclic group mentioned above. R 12b may be either a single bond or a divalent linking group. Since it has excellent effects of the present invention, it is preferably a divalent linking group.

[0071] R 12b The divalent linking group in is not particularly limited, but examples of suitable ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

[0072] ·A divalent hydrocarbon group which may have a substituent The hydrocarbon group as the divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated. Usually, a saturated hydrocarbon group is preferred. More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

[0073] The number of carbon atoms of the linear or branched aliphatic hydrocarbon group is preferably 1 or more and 10 or less, more preferably 1 or more and 8 or less, and still more preferably 1 or more and 5 or less.

[0074] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [-CH 2 -], an ethylene group [-(CH 2 ) 2 -], a trimethylene group [-(CH 2 ) 3 -], a tetramethylene group [-(CH 2 ) 4 -], a pentamethylene group [-(CH 2 ) 5 -], etc. may be mentioned.

[0075] As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - and other alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 - and other alkylethylene groups; -CH(CH 3 )CH 2 CH2 -, -CH 2 CH(CH 3 )CH 2 - and other alkyltrimethylene groups such as -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 - and other alkyltetramethylene groups and other alkylalkylene groups. Examples of the alkyl group in the alkylalkylene group include linear alkyl groups having 1 to 5 carbon atoms, which are preferred.

[0076] The above linear or branched aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxo group (=O), etc.

[0077] Examples of the aliphatic hydrocarbon group containing a ring in the above structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the above linear or branched aliphatic hydrocarbon group are the same as those described above.

[0078] The number of carbon atoms of the cyclic aliphatic hydrocarbon group is preferably 3 or more and 20 or less, and more preferably 3 or more and 12 or less.

[0079] The cyclic aliphatic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from monocycloalkane is preferable. The number of carbon atoms of the monocycloalkane is preferably 3 or more and 6 or less. Specifically, cyclopentane, cyclohexane and the like can be mentioned. As the polycyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from polycycloalkane is preferable. The number of carbon atoms of the polycycloalkane is preferably 7 or more and 12 or less. Specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like can be mentioned.

[0080] The cyclic aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (=O), and the like.

[0081] As the alkyl group as the above-mentioned substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are more preferable.

[0082] As the alkoxy group as the above-mentioned substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are particularly preferable.

[0083] Examples of the halogen atom as the above-mentioned substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

[0084] Examples of the halogenated alkyl group as the above-mentioned substituent include a group in which some or all of the hydrogen atoms of the aforementioned alkyl group are substituted with the above-mentioned halogen atoms.

[0085] The cyclic aliphatic hydrocarbon group may have a part of the carbon atoms constituting its ring structure substituted with -O- or -S-. Examples of the substituent containing a heteroatom include -O-, -C(=O)-O-, -S-, -S(=O) 2 -, -S(=O) 2 -O- is preferred.

[0086] The aromatic hydrocarbon group as a divalent hydrocarbon group is a divalent hydrocarbon group having at least one aromatic ring, and may have a substituent. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms of the aromatic ring is preferably 5 or more and 30 or less, more preferably 5 or more and 20 or less, still more preferably 6 or more and 15 or less, and particularly preferably 6 or more and 12 or less. However, the number of carbon atoms does not include the number of carbon atoms of the substituent.

[0087] Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom; and the like. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

[0088] Specific examples of the aromatic hydrocarbon group as a divalent hydrocarbon group include a group obtained by removing two hydrogen atoms from the above aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the above aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.); and the like.

[0089] The number of carbon atoms of the alkylene group bonded to the above aryl group or heteroaryl group is preferably 1 or more and 4 or less, more preferably 1 or more and 2 or less, and particularly preferably 1.

[0090] In the above aromatic hydrocarbon group, the hydrogen atoms of the aromatic hydrocarbon group may be substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of the substituents include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (=O), and the like.

[0091] As the alkyl group as the above substituent, an alkyl group having 1 or more and 5 or less carbon atoms is preferable, and a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and a tert-butyl group are more preferable.

[0092] As the alkoxy group as the above substituent, an alkoxy group having 1 or more and 5 or less carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are preferable, and a methoxy group and an ethoxy group are more preferable.

[0093] Examples of the halogen atom as the above substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferable.

[0094] Examples of the halogenated alkyl group as the above substituent include groups in which some or all of the hydrogen atoms of the aforementioned alkyl group are substituted with the above halogen atoms.

[0095] ·A divalent linking group containing a heteroatom The heteroatom in the divalent linking group containing a heteroatom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

[0096] As the divalent linking group containing a heteroatom, specifically, -O-, -C(=O)-, -C(=O)-O-, -O-C(=O)-O-, -S-, -S(=O) 2 -, -S(=O) 2 -O-, -NH-, -NH-C(=O)-, -NH-C(=NH)-, =N- and other non-hydrocarbon linking groups, combinations of at least one of these non-hydrocarbon linking groups and a divalent hydrocarbon group, etc. may be mentioned. Examples of the divalent hydrocarbon group include the same ones as the divalent hydrocarbon group which may have the above-mentioned substituents, and linear or branched aliphatic hydrocarbon groups are preferred.

[0097] Among the above, the -NH- in -C(=O)-NH-, -NH-, and the H in -NH-C(=NH)- may each be substituted with a substituent such as an alkyl group or an acyl group. The number of carbon atoms of the substituent is preferably 1 or more and 10 or less, more preferably 1 or more and 8 or less, and particularly preferably 1 or more and 5 or less.

[0098] R 12b As the divalent linking group in, particularly, a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent linking group containing a heteroatom is preferred.

[0099] R 12b When the divalent linking group in is a linear or branched alkylene group, the number of carbon atoms of the alkylene group is preferably 1 or more and 10 or less, more preferably 1 or more and 6 or less, particularly preferably 1 or more and 4 or less, and most preferably 1 or more and 3 or less. Specifically, in the description of the "divalent hydrocarbon group which may have a substituent" as the above-mentioned divalent linking group, the same ones as the linear alkylene group and the branched alkylene group mentioned as the linear or branched aliphatic hydrocarbon group may be mentioned.

[0100] R 12bWhen the divalent linking group in [R] is a cyclic aliphatic hydrocarbon group, examples of the cyclic aliphatic hydrocarbon group include the same groups as those listed as the cyclic aliphatic hydrocarbon groups under the description of the "divalent hydrocarbon group which may have a substituent" as the divalent linking group described above, among the "aliphatic hydrocarbon groups containing a ring in the structure".

[0101] As the cyclic aliphatic hydrocarbon group, a group obtained by removing two or more hydrogen atoms from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable.

[0102] R 12b When the divalent linking group in [R] is a divalent linking group containing a heteroatom, preferable examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O) 2 -, -S(=O) 2 -O-, general formula -Y 1 -O-Y 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 -, or -Y 1 -O-C(=O)-Y 2 -represented groups [wherein Y 1 , and Y 2 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m' is an integer of 0 or more and 3 or less.], etc. are included.

[0103] R 12b When the divalent linking group in [R] is -NH-, the hydrogen atom in -NH- may be substituted with a substituent such as an alkyl group or an acyl group. The number of carbon atoms of the substituent (alkyl group, acyl group, etc.) is preferably 1 or more and 10 or less, more preferably 1 or more and 8 or less, and particularly preferably 1 or more and 5 or less.

[0104] Formula -Y 1 -O-Y 2 -, -[Y1 -C(=O)-O] m’ -Y 2 - or -Y 1 -O-C(=O)-Y 2 - among them, Y 1 and Y 2 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same ones as the "divalent hydrocarbon group which may have a substituent" described as the divalent linking group above.

[0105] Y 1 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group and an ethylene group.

[0106] Y 2 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, and an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[0107] In the group represented by the formula -[Y 1 -C(=O)-O] m’ -Y 2 -, m' is an integer of 0 or more and 3 or less, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, and particularly preferably 1. That is, in the group represented by the formula -[Y 1 -C(=O)-O] m’ -Y 2 -, as the group represented by the formula -Y 1 -C(=O)-O-Y 2 - is particularly preferred. Among them, the formula -(CH 2 ) a’ -C(=O)-O-(CH 2 ) b’The group represented by - is preferred. In the formula, a' is an integer of 1 or more and 10 or less, preferably an integer of 1 or more and 8 or less, more preferably an integer of 1 or more and 5 or less, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 or more and 10 or less, preferably an integer of 1 or more and 8 or less, more preferably an integer of 1 or more and 5 or less, still more preferably 1 or 2, and most preferably 1.

[0108] R 12b Regarding the divalent linking group in, as the divalent linking group containing a heteroatom, an organic group composed of a combination of at least one non-hydrocarbon group and a divalent hydrocarbon group is preferred. Among them, a linear group having an oxygen atom as a heteroatom, for example, a group containing an ether bond or an ester bond, is preferred, and the aforementioned formula -Y 1 -O-Y 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 -, or -Y 1 -O-C(=O)-Y 2 -represented group is more preferred, and the aforementioned formula -[Y 1 -C(=O)-O] m’ -Y 2 -, or -Y 1 -O-C(=O)-Y 2 -represented group is particularly preferred.

[0109] R 12b As the divalent linking group in, an alkylene group or one containing an ester bond (-C(=O)-O-) is preferred.

[0110] The alkylene group is preferably a linear or branched alkylene group. Suitable examples of the linear aliphatic hydrocarbon group include a methylene group [-CH 2 -], an ethylene group [-(CH 2 ) 2 -], a trimethylene group [-(CH 2 ) 3 -], a tetramethylene group [-(CH 2 ) 4 -], and a pentamethylene group [-(CH 2 ) 5-] etc. can be mentioned. Preferred examples of the branched-chain alkylene group include -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 - etc. alkylethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 - etc. alkyltrimethylene groups; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 - etc. alkyltetramethylene groups and other alkylalkylene groups etc. can be mentioned.

[0111] As the divalent linking group containing an ester bond, in particular, the formula: -R 13b -C(=O)-O-[wherein, R 13bis a divalent linking group. A group represented by [ ] is preferred. That is, the structural unit (a2-S) is preferably a structural unit represented by the following formula (a2-S1-1).

[0112] [Chemical formula] (In the formula, R and R 11b are the same as described above, and R 13b is a divalent linking group.)

[0113] R 13b is not particularly limited, and examples thereof include the same as the divalent linking group in the aforementioned R 12b . R 13b As the divalent linking group, a linear or branched alkylene group, an aliphatic hydrocarbon group containing a ring in the structure, or a divalent linking group containing a heteroatom is preferred, and a linear or branched alkylene group, or a divalent linking group containing an oxygen atom as a heteroatom is preferred.

[0114] As the linear alkylene group, a methylene group or an ethylene group is preferred, and a methylene group is particularly preferred. As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferred, -CH(CH 3 )-, -C(CH 3 ) 2 -, or -C(CH 3 ) 2 CH 2 - is particularly preferred.

[0115] As the divalent linking group containing an oxygen atom, a divalent linking group containing an ether bond or an ester bond is preferred, and the aforementioned -Y 1 -O-Y 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 -, or -Y 1 -O-C(=O)-Y 2 - is more preferred. Y 1 , and Y 2is each independently a divalent hydrocarbon group which may have a substituent, and m' is an integer of 0 or more and 3 or less. Among them, -Y 1 -O-C(=O)-Y 2 - is preferred, and -(CH 2 ) c -O-C(=O)-(CH 2 ) d - represented by the group is particularly preferred. c is an integer of 1 or more and 5 or less, and 1 or 2 is preferred. d is an integer of 1 or more and 5 or less, and 1 or 2 is preferred.

[0116] As the structural unit (a2-S), in particular, the structural unit represented by the following formula (a2-S1-11) or (a2-S1-12) is preferred, and the structural unit represented by the formula (a2-S1-12) is more preferred.

[0117]

Chemical formula

[0118] In the formula (a2-S1-11), A' is preferably a methylene group, an oxygen atom (-O-), or a sulfur atom (-S-).

[0119] R 13b is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in R 13b , the same ones as the linear or branched alkylene group and the divalent linking group containing an oxygen atom described above can be mentioned respectively.

[0120] As the structural unit represented by the formula (a2-S1-12), in particular, the structural unit represented by the following formula (a2-S1-12a) or (a2-S1-12b) is preferred.

[0121]

Chemical formula

[0122] [Constituent unit (a2-L)] Examples of the constituent unit (a2-L) include, for example, those in which R in the aforementioned formula (a2-S1) 11b is substituted with a lactone-containing cyclic group, and more specifically, the constituent units represented by the following formulas (a2-L1) to (a2-L5) can be mentioned.

[0123] [Chemical formula] (In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; R’ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group, or a cyano group, and R” is a hydrogen atom or an alkyl group; R 12b is a single bond or a divalent linking group, s” is an integer of 0 or more and 2 or less; A” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom; r is 0 or 1.)

[0124] R in the formulas (a2-L1) to (a2-L5) is the same as described above. Examples of the alkyl group, alkoxy group, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in R’ are the same as those mentioned above for the substituents which the -SO 2 -containing cyclic group may have.

[0125] Considering industrial availability and the like, R’ is preferably a hydrogen atom. The alkyl group in R” may be linear, branched, or cyclic. When “R” is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. When “R” is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. Specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Examples of “A” include the same ones as A’ in the aforementioned formula (3-1). “A” is preferably an alkylene group having 1 to 5 carbon atoms, an oxygen atom (-O-), or a sulfur atom (-S-), more preferably an alkylene group having 1 to 5 carbon atoms or -O-. As the alkylene group having 1 to 5 carbon atoms, a methylene group or a dimethylmethylene group is more preferable, and a methylene group is most preferable.

[0126] R 12b is the same as R in the aforementioned formula (a2-S1). 12b In the formula (a2-L1), s” is preferably 1 or 2. Specific examples of the structural units represented by the aforementioned formulas (a2-L1) to (a2-L3) are exemplified below. In the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0127]

Chemical formula

[0128]

Chemical formula

[0129]

Chem.

[0130] As the structural unit (a2-L), at least one selected from the group consisting of the structural units represented by the aforementioned formulas (a2-L1) to (a2-L5) is preferable, at least one selected from the group consisting of the structural units represented by the formulas (a2-L1) to (a2-L3) is more preferable, at least one selected from the group consisting of the structural units represented by the aforementioned formula (a2-L1) or (a2-L3) is particularly preferable, and the structural unit represented by the formula (a2-L1) is most preferable. Among them, at least one selected from the group consisting of the structural units represented by the aforementioned formulas (a2-L1-1), (a2-L1-2), (a2-L2-1), (a2-L2-7), (a2-L2-12), (a2-L2-14), (a2-L3-1), and (a2-L3-5) is preferable.

[0131] In addition, as the structural unit (a2-L), the structural units represented by the following formulas (a2-L6) to (a2-L7) are also preferable.

Chem.

[0132] The content ratio of the structural unit (a2) in the resin (A) (when a plurality of types are contained, the total content ratio) is preferably 5% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 55% by mass or less, and particularly preferably 15% by mass or more and 50% by mass or less.

[0133] As the total content ratio of the constitutional unit (a1) and the constitutional unit (a2) in the resin (A) (when a plurality of types are contained, the total content ratio), 50% by mass or more is preferable, 70% by mass or more is more preferable, and 90% by mass or more is particularly preferable. The total content ratio may be 100% by mass.

[0134] Furthermore, for the purpose of appropriately controlling the physical and chemical properties, the resin (A) can contain other polymerizable compounds as constitutional units. Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds.

[0135] Examples of such polymerizable compounds include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxy group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and cyclohexyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate; diesters of dicarboxylic acids such as diethyl maleate and dibutyl fumarate; vinyl group-containing aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide; and the like.

[0136] The polystyrene-reduced mass average molecular weight of the resin (A) described above is preferably 1,000 or more and 500,000 or less, more preferably 2,000 or more and 100,000 or less, and even more preferably 3,000 or more and 50,000 or less. By setting the mass average molecular weight to such a value, it is easy to maintain sufficient strength of the photosensitive resin composition layer without reducing the peelability from the substrate.

[0137] In addition, the dispersity of the resin (A) is preferably 1.05 or more and 2 or less, more preferably 1.2 or more and 1.9 or less, and even more preferably 1.3 or more and 1.8 or less. Here, the dispersity is the value obtained by dividing the mass average molecular weight by the number average molecular weight.

[0138] The Onishi parameter of the resin (A) is preferably 3 or more and 5 or less, and more preferably 3.5 or more and 4.5 or less. In this specification, the Onishi parameter means the value represented by the formula "total number of atoms / (number of carbon atoms - number of oxygen atoms)". The Onishi parameter of the resin (A) is obtained by counting the number of each atom from the structural formula of each repeating unit contained in the resin (A) to obtain the Onishi parameter of each repeating unit, and adding up the values obtained by multiplying the content ratio (molar ratio) of each repeating unit.

[0139] The ring parameter of the resin (A) is preferably less than 1, and more preferably 0.5 or less. Also, the lower limit of the ring parameter is, for example, 0.1 or more, or 0.2 or more. In this specification, the ring parameter means the value represented by the formula "total atomic weight of carbon atoms in the cyclic structure / total atomic weight of all atoms". The ring parameter of the resin (A) is obtained by obtaining the ring parameter of each repeating unit from the structural formula of each repeating unit contained in the resin (A), and adding up the values obtained by multiplying the content ratio (molar ratio) of each repeating unit. The ring parameter is an index of dry etching resistance.

[0140] The content of the resin (A) is preferably 30% by mass or more and 99% by mass or less, more preferably 50% by mass or more and 99% by mass or less, still more preferably 70% by mass or more and 99% by mass or less, and particularly preferably 90% by mass or more and 99% by mass or less, based on the total solid content of the photosensitive resin composition.

[0141] <Photoacid generator (B)> The photoacid generator (B) is a compound that generates an acid upon irradiation with actinic rays or radiation, and is not particularly limited as long as it is a compound that generates an acid directly or indirectly by light. As the photoacid generator (B), the photoacid generators of the first to fifth embodiments described below are preferable, and the photoacid generator of the first embodiment is more preferable in terms of easily forming a fine microlens pattern in both the case of using a KrF excimer laser and the case of using an ArF excimer laser. Hereinafter, preferable ones among the photoacid generators (B) used in the photosensitive resin composition will be described as the first to fifth embodiments.

[0142] As a first embodiment of the photoacid generator (B), a compound represented by the following formula (b1) can be mentioned.

[0143]

Chemical formula

[0144] In the above formula (b1), X 1a represents a sulfur atom or an iodine atom with valence g, and g is 1 or 2. h represents the number of repeating units of the structure in parentheses. R 1a is an organic group bonded to X 1a and represents an aryl group having 6 to 30 carbon atoms, a heterocyclic group having 4 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, or an alkynyl group having 2 to 30 carbon atoms. R 1ais optionally substituted with at least one selected from the group consisting of an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkyleneoxy group, an amino group, a cyano group, a nitro group, and a halogen atom. R 1a The number of them is g + h(g - 1) + 1, and R 1a may be the same as or different from each other. Also, two or more R 1a may be directly bonded to each other or bonded via -O-, -S-, -SO-, -SO 2 -, -NH-, -NR 2a -, -CO-, -COO-, -CONH-, an alkylene group having 1 to 3 carbon atoms, or a phenylene group to form a ring structure containing X 1a . R 2a is an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0145] X 2a has a structure represented by the following formula (b2).

[0146]

Chemical formula

[0147] In the above formula (b2), X 4a represents a divalent group of an alkylene group having 1 to 8 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a heterocyclic compound having 8 to 20 carbon atoms, and X 4a is optionally substituted with at least one selected from the group consisting of an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, a hydroxy group, a cyano group, a nitro group, and a halogen atom. X 5a is -O-, -S-, -SO-, -SO 2 -, -NH-, -NR 2arepresents -CO-, -COO-, -CONH-, an alkylene group having 1 to 3 carbon atoms, or a phenylene group. h represents the number of repeating units of the structure in parentheses. h + 1 X 4a and h X 5a may be the same or different from each other. R 2a is the same as the above definition.

[0148] X 3a- is a counter ion of onium, and examples thereof include a fluorinated alkyl fluorophosphate anion represented by the following formula (b17) or a borate anion represented by the following formula (b18).

[0149]

Chemical formula

[0150] In the above formula (b17), R 3a represents an alkyl group in which 80% or more of the hydrogen atoms are substituted with fluorine atoms. j indicates the number thereof and is an integer of 1 to 5. j R 3a may be the same or different from each other.

[0151]

Chemical formula

[0152] In the above formula (b18), R 4a ~R 7a each independently represents a fluorine atom or a phenyl group, and a part or all of the hydrogen atoms of the phenyl group may be substituted with at least one selected from the group consisting of a fluorine atom and a trifluoromethyl group.

[0153] X 3a- Examples of X

Chemical formula

[0154] R b33 Examples of the substituent of R include an alkyl group and a heteroatom-containing substituent.

[0155] As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are more preferable.

[0156] Examples of the heteroatom-containing substituent as the substituent include, for example, a halogen atom, an alkoxy group, a hydroxyl group, -C(=O)-R b25 [R b25 is an alkyl group.], -COOR b26 [R b26 is a hydrogen atom or an alkyl group.], a halogenated alkyl group, a halogenated alkoxy group, an amino group, an amide group, a nitro group, an oxygen atom (=O), a sulfur atom, a sulfonyl group (SO 2 ) and the like.

[0157] Examples of the halogen atom as the heteroatom-containing substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

[0158] As the alkyl group in the alkoxy group as a heteroatom-containing substituent, it may be linear, branched, or cyclic, or a combination thereof. The number of carbon atoms of the alkyl group in the alkoxy group is preferably 1 or more and 30 or less. When the alkyl group is linear or branched, the number of carbon atoms is preferably 1 or more and 20 or less, more preferably 1 or more and 17 or less, still more preferably 1 or more and 15 or less, and particularly preferably 1 or more and 10 or less. When the alkyl group is cyclic (when it is a cycloalkyl group), the number of carbon atoms is preferably 3 or more and 30 or less, more preferably 3 or more and 20 or less, still more preferably 3 or more and 15 or less, particularly preferably 4 or more and 12 or less, and most preferably 5 or more and 10 or less. When the alkyl group is cyclic, it may be monocyclic or polycyclic. Specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes, groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes can be exemplified. Specific examples of monocycloalkanes include cyclopentane and cyclohexane. Specific examples of polycycloalkanes include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In these cycloalkyl groups, some or all of the hydrogen atoms bonded to the ring may or may not be substituted with substituents such as fluorine atoms and fluorinated alkyl groups.

[0159] -C(=O)-R as a heteroatom-containing substituent b25 , -COOR b26 In, R b25 , and R b26 As the alkyl group in, the same alkyl groups as those listed as the alkyl group in the aforementioned alkoxy group can be mentioned.

[0160] As the alkyl group in the halogenated alkyl group as a heteroatom-containing substituent, the same alkyl groups as those listed as the alkyl group in the alkoxy group can be mentioned. As the halogenated alkyl group, a fluorinated alkyl group is particularly preferred.

[0161] Examples of the halogenated alkoxy group as the heteroatom-containing substituent include groups in which some or all of the hydrogen atoms of the alkoxy group are substituted with the halogen atoms. As the halogenated alkoxy group, a fluorinated alkoxy group is preferred.

[0162] R b33 When the symbols (r1, r2) attached to b33 R are integers of 2 or more, the plurality of Rs in the same compound may be the same or different from each other. R b34 The alkyl group in R may be linear, branched, or cyclic. The number of carbon atoms of the alkyl group is preferably 1 or more and 4 or less. R b34 Examples of the halogenated alkyl group in R include groups in which some or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, etc., and a fluorine atom is preferred.

[0163] r1 and r2 are each preferably an integer of 0 or more and 2 or less, more preferably 0 or 1. v0 is preferably 0 or more and 2 or less, more preferably 0 or 1. t3 is preferably 1 or 2, more preferably 1. q3 is preferably an integer of 1 or more and 5 or less, more preferably an integer of 1 or more and 3 or less, and particularly preferably 1.

[0164] Examples of the onium ion in the compound represented by the above formula (b1) include triphenylsulfonium, tri-p-tolylsulfonium, 4-(phenylthio)phenyl diphenylsulfonium, bis[4-(diphenylsulfonio)phenyl]sulfide, bis[4-{bis[4-(2-hydroxyethoxy)phenyl]sulfonio}phenyl]sulfide, bis{4-[bis(4-fluorophenyl)sulfonio]phenyl}sulfide, 4-(4-benzoyl-2-chlorophenylthio)phenyl bis(4-fluorophenyl)sulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yl di-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yl diphenylsulfonium, 2-[(diphenyl)sulfonio]thioxanthone, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyl di-p-tolylsulfonium, 4-(4-benzoylphenylthio)phenyl diphenylsulfonium, diphenyl phenacylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 2-naphthylmethyl (1-ethoxycarbonyl)ethylsulfonium, 4-hydroxyphenylmethyl phenacylsulfonium, phenyl[4-(4-biphenylthio)phenyl]4-biphenylsulfonium, phenyl[4-(4-biphenylthio)phenyl]3-biphenylsulfonium, [4-(4-acetophenythio)phenyl]diphenylsulfonium, octadecylmethyl phenacylsulfonium, diphenyliodonium, di-p-tolyliodonium, bis(4-dodecylphenyl)iodonium, bis(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyl iodonium, bis(4-decyloxy)phenyl iodonium, 4-(2-hydroxytetradecyloxy)phenylphenyl iodonium, 4-isopropylphenyl (p-tolyl)iodonium, or 4-isobutylphenyl (p-tolyl)iodonium, etc.

[0165] Among the onium ions in the compound represented by the above formula (b1), preferred onium ions include sulfonium ions represented by the following formula (b19) because they easily form a fine microlens pattern regardless of whether a KrF excimer laser or an ArF excimer laser is used.

[0166]

Chemical formula

[0167] In the above formula (b19), R 8a each independently represents a group selected from the group consisting of a hydrogen atom, alkyl, hydroxy, alkoxy, alkylcarbonyl, alkylcarbonyloxy, alkyloxycarbonyl, halogen atom, aryl which may have a substituent, and arylcarbonyl. R 8a is preferably a hydrogen atom or an alkyl group. The number of carbon atoms of the alkyl group as R 8a is preferably 1 or more and 5 or less.

[0168] In the fluorinated alkyl fluorophosphate anion represented by the above formula (b17), R 3a represents an alkyl group substituted with a fluorine atom, preferably having 1 or more and 8 or less carbon atoms, more preferably 1 or more and 4 or less carbon atoms. Specific examples of the alkyl group include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, octyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl; and cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl. The ratio of hydrogen atoms of the alkyl group substituted with fluorine atoms is usually 80% or more, preferably 90% or more, more preferably 100%. When the substitution rate of fluorine atoms is less than 80%, the acid strength of the onium fluorinated alkyl fluorophosphate represented by the above formula (b1) decreases.

[0169] Particularly preferred R 3ais a linear or branched perfluoroalkyl group with 1 to 4 carbon atoms and a fluorine atom substitution rate of 100%. Specific examples include CF 3 and CF 3 CF 2 , (CF 3 ) 2 CF, CF 3 CF 2 CF 2 , CF 3 CF 2 CF 2 CF 2 , (CF 3 ) 2 CFCF 2 , CF 3 CF 2 (CF 3 )CF, (CF 3 ) 3 C. The number j of R 3a is an integer from 1 to 5, preferably from 2 to 4, and particularly preferably 2 or 3.

[0170] Specific examples of preferred fluorinated alkyl fluorophosphate anions include [(CF 3 CF 2 ) 2 PF 4 - , [(CF 3 CF 2 ) 3 PF 3 - , [((CF 3 ) 2 CF) 2 PF 4 - , [((CF 3 ) 2 CF) 3 PF 3 - , [(CF 3 CF 2 CF 2 ) 2 PF 4 - , [(CF 3 CF 2 CF 2 ) 3 PF 3 ​​​​​​- , [((CF 3 ) 2 CFCF 2 ) 2 PF 4 - , [((CF 3 ) 2 CFCF 2 ) 3 PF 3 - , [(CF 3 CF 2 CF 2 CF 2 ) 2 PF 4 - , or [(CF 3 CF 2 CF 2 ) 3 PF 3 - are mentioned, among which, [(CF 3 CF 2 ) 3 PF 3 - , [(CF 3 CF 2 CF 2 ) 3 PF 3 - , [((CF 3 ) 2 CF) 3 PF 3 - , [((CF 3 ) 2 CF) 2 PF 4 - , [((CF 3 ) 2 CFCF 2 ) 3 PF 3 - , or [((CF 3 ) 2 CFCF 2 ) 2 PF 4 - are particularly preferred.

[0171] ​​​​​​​​​​Preferred specific examples of the borate anion represented by the above formula (b18) include tetrakis(pentafluorophenyl)borate ([B(C 6 F 5 ) 4 - ), tetrakis[(trifluoromethyl)phenyl]borate ([B(C 6 H 4 CF 3 ) 4 - ), difluorobis(pentafluorophenyl)borate ([(C 6 F 5 ) 2 BF 2 - ), trifluoro(pentafluorophenyl)borate ([(C 6 F 5 )BF 3 - ), tetrakis(difluorophenyl)borate ([B(C 6 H 3 F 2 ) 4 - ) and the like. Among these, tetrakis(pentafluorophenyl)borate ([B(C 6 F 5 ) 4 - ) is particularly preferred.

[0172] ​​​​​​As a second aspect of the photoacid generator (B), 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-ethyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-propyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dimethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-diethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dipropoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-ethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-propoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,4-methylenedioxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-(3,4-methylenedioxyphenyl)-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxystyrylphenyl)-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxystyrylphenyl)-s-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(2-furyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(5-methyl-2-furyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,5-(Dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4-methylenedioxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, halogen-containing triazine compounds such as tris(1,3-dibromopropyl)-1,3,5-triazine and tris(2,3-dibromopropyl)-1,3,5-triazine, and halogen-containing triazine compounds represented by the following formula (b3) such as tris(2,3-dibromopropyl)isocyanurate are included.,

[0173]

Chemical formula

[0174] In the above formula (b3), R 9a 、R 10a 、R 11a each independently represents a halogenated alkyl group.,

[0175] Also, as a third aspect of the photoacid generator (B), α-(p-toluenesulfonyloxyimino)-phenylacetonitrile, α-(benzenesulfonyloxyimino)-2,4-dichlorophenylacetonitrile, α-(benzenesulfonyloxyimino)-2,6-dichlorophenylacetonitrile, α-(2-chlorobenzenesulfonyloxyimino)-4-methoxyphenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, and compounds represented by the following formula (b4) containing an oxime sulfonate group are included.,

[0176]

Chemical formula

[0177] In the above formula (b4), R 12a represents a monovalent, divalent, or trivalent organic group, and R 13arepresents a substituted or unsubstituted saturated hydrocarbon group, an unsaturated hydrocarbon group, or an aromatic group, and n represents the number of repeating units of the structure within the parentheses.

[0178] In the above formula (b4), examples of the aromatic group include aryl groups such as a phenyl group and a naphthyl group, and heteroaryl groups such as a furyl group and a thienyl group. These may have one or more suitable substituents on the ring, such as a halogen atom, an alkyl group, an alkoxy group, a nitro group, etc. Also, R 13a is particularly preferably an alkyl group having 1 to 6 carbon atoms, and examples include a methyl group, an ethyl group, a propyl group, and a butyl group. In particular, R 12a is an aromatic group, and a compound in which R 13a is an alkyl group having 1 to 4 carbon atoms is preferred.

[0179] As the acid generator represented by the above formula (b4), when n = 1, R 12a is any of a phenyl group, a methylphenyl group, and a methoxyphenyl group, and a compound in which R 13a is a methyl group, specifically, α-(methylsulfonyloxyimino)-1-phenylacetonitrile, α-(methylsulfonyloxyimino)-1-(p-methylphenyl)acetonitrile, α-(methylsulfonyloxyimino)-1-(p-methoxyphenyl)acetonitrile, [2-(propylsulfonyloxyimino)-2,3-dihydroxythiophene-3-ylidene](o-tolyl)acetonitrile, etc. are exemplified. When n = 2, examples of the acid generator represented by the above formula (b4) specifically include acid generators represented by the following formula.

[0180]

Chemical formula

[0181] As a fourth aspect of the photoacid generator (B), an onium salt having a naphthalene ring in the cationic part can be mentioned. The phrase "having a naphthalene ring" means having a structure derived from naphthalene, and means that at least two ring structures and their aromaticity are maintained. This naphthalene ring may have a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, or the like as a substituent. The structure derived from the naphthalene ring may be a monovalent group (with one free valence) or a divalent group (with two or more free valences) or more, but it is preferably a monovalent group (however, when this is the case, the free valence is counted excluding the part bonded to the above substituent). The number of naphthalene rings is preferably 1 or more and 3 or less.

[0182] As the cationic part of such an onium salt having a naphthalene ring in the cationic part, a structure represented by the following formula (b5) is preferable.

[0183]

Chemical formula

[0184] In the above formula (b5), at least one of R 14a , R 15a , R 16a represents a group represented by the following formula (b6), and the rest represent a linear or branched alkyl group having 1 to 6 carbon atoms, a phenyl group which may have a substituent, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. Alternatively, one of R 14a , R 15a , R 16a is a group represented by the following formula (b6), and the remaining two are each independently a linear or branched alkylene group having 1 to 6 carbon atoms, and the ends thereof may be bonded to form a ring.

[0185]

Chemical formula

[0186] In the above formula (b6), R 17a , R 18a each independently represents a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, or a linear or branched alkyl group having 1 to 6 carbon atoms, and R 19a represents 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 or more and 2 or less, and l + m is 3 or less. However, when there are a plurality of R 17a , they may be the same as or different from each other. Also, when there are a plurality of R 18a , they may be the same as or different from each other.

[0187] Among the above R 14a , R 15a , R 16a , the number of the groups represented by the above formula (b6) 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, and the ends of these may be bonded to form a ring. In this case, the above two alkylene groups form a 3- to 9-membered ring including a sulfur atom. The number of atoms (including the sulfur atom) constituting the ring is preferably 5 or more and 6 or less.

[0188] Examples of the substituent that the above alkylene group may have include an oxygen atom (in this case, forming a carbonyl group together with the carbon atom constituting the alkylene group), a hydroxyl group, and the like.

[0189] 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, a linear or branched alkyl group having 1 to 6 carbon atoms, and the like.

[0190] Examples of those suitable as these cation moieties include those represented by the following formulas (b7) and (b8), and in particular, the structure represented by the following formula (b8) is preferable.

[0191] [Chemical formula]

[0192] As such a cationic moiety, either an iodonium salt or a sulfonium salt may be used, but a sulfonium salt is desirable in terms of acid generation efficiency and the like.

[0193] Therefore, as a suitable anionic moiety of an onium salt having a naphthalene ring in the cationic moiety, an anion capable of forming a sulfonium salt is desirable.

[0194] As the anionic moiety of such an acid generator, it is a fluoroalkylsulfonate ion or an arylsulfonate ion in which part or all of the hydrogen atoms are fluorinated.

[0195] The alkyl group in the fluoroalkylsulfonate ion may be linear, branched, or cyclic with 1 to 20 carbon atoms, and is preferably 1 to 10 carbon atoms from the bulkiness and diffusion distance of the generated acid. In particular, branched or cyclic ones are preferable because of their short diffusion distance. Also, because they can be synthesized inexpensively, a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, etc. can be mentioned as preferable ones.

[0196] The aryl group in the arylsulfonate ion is an aryl group having 6 to 20 carbon atoms, and examples include a phenyl group and a naphthyl group which may or may not be substituted with an alkyl group or a halogen atom. In particular, an aryl group having 6 to 10 carbon atoms is preferable because it can be synthesized inexpensively. Specific examples of preferable ones include a phenyl group, a toluenesulfonyl group, an ethylphenyl group, a naphthyl group, a methylnaphthyl group, etc.

[0197] In the above-mentioned fluoroalkylsulfonate ion or arylsulfonate ion, when part 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. In particular, those in which all hydrogen atoms are replaced by fluorine atoms are preferred because the acid strength becomes stronger. Specific examples of such substances include trifluoromethanesulfonate, perfluorobutanesulfonate, perfluorooctanesulfonate, perfluorobenzenesulfonate, and the like.

[0198] Among these, preferred anion moieties include those represented by the following formula (b9).

[0199]

Chemical formula

[0200] In the above formula (b9), R 20a is a group represented by the following formulas (b10), (b11), and (b12).

[0201]

Chemical formula

[0202] In the above formula (b10), x represents an integer of 1 or more and 4 or less. Also, in the above formula (b11), R 21a represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 or more and 6 or less carbon atoms, or a linear or branched alkoxy group having 1 or more and 6 or less carbon atoms, and y represents an integer of 1 or more and 3 or less. Among these, from the viewpoint of safety, trifluoromethanesulfonate and perfluorobutanesulfonate are preferred.

[0203] In addition, as the anion moiety, those containing nitrogen represented by the following formulas (b13) and (b14) can also be used.

[0204]

Chemical formula

[0205] In the above formulas (b13) and (b14), X a represents a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, the number of carbon atoms of the alkylene group is 2 or more and 6 or less, preferably 3 or more and 5 or less, and most preferably 3 carbon atoms. Also, Y a , Z a each independently represents a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, the number of carbon atoms of the alkyl group is 1 or more and 10 or less, preferably 1 or more and 7 or less, and more preferably 1 or more and 3 or less.

[0206] X a The smaller the number of carbon atoms of the alkylene group, or Y a , Z a The smaller the number of carbon atoms of the alkyl group, the better the solubility in an organic solvent, which is preferable.

[0207] Also, in the alkylene group of X a or Y a , Z a the alkyl group, the larger the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The ratio of fluorine atoms, that is, the fluorination rate, in the alkylene group or alkyl group 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.

[0208] Preferred examples of such an onium salt having a naphthalene ring in the cation moiety include compounds represented by the following formulas (b15) and (b16).

[0209]

Chemical formula

[0210] Also, as the fifth aspect of the photoacid generator (B), bissulfonyldiazomethanes such as bis(p-toluenesulfonyl)diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane; nitrobenzyl derivatives such as 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, nitrobenzyl tosylate, dinitrobenzyl tosylate, nitrobenzyl sulfonate, nitrobenzyl carbonate, dinitrobenzyl carbonate; sulfonic acid esters such as pyrogallol trimesylate, pyrogallol tritosylate, benzyl tosylate, benzyl sulfonate, N-methylsulfonyloxysuccinimide, N-trichloromethylsulfonyloxysuccinimide, N-phenylsulfonyloxymaleimide, N-methylsulfonyloxyphthalimide; trifluoromethanesulfonic acid esters such as N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)-1,8-naphthalimide, N-(trifluoromethylsulfonyloxy)-4-butyl-1,8-naphthalimide; onium salts such as diphenyliodonium hexafluorophosphate, (4-methoxyphenyl)phenyliodonium trifluoromethanesulfonate, bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, (p-tert-butylphenyl)diphenylsulfonium trifluoromethanesulfonate; benzoin tosylates such as benzoin tosylate, α-methylbenzoin tosylate; and other diphenyliodonium salts, triphenylsulfonium salts, phenyldiazonium salts, benzyl carbonate, etc. may be mentioned.

[0211] As the photoacid generator (B), a naphthalic acid derivative represented by the following formula (b21) is also preferable.

Chemical formula

[0212] The organic group as R 22a is not particularly limited as long as it does not inhibit the object of the present invention. The organic group may be a hydrocarbon group and may contain heteroatoms such as O, N, S, P, and halogen atoms. Further, the structure of the organic group may be linear, branched, cyclic, or a combination of these structures.

[0213] Preferred organic groups as R 22a include a halogen atom and / or an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may be substituted with an alkylthio group, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, an alkylaryl group having 7 to 20 carbon atoms which may have a substituent, a camphor-10-yl group, and the following formula (b21a): -R 27a -(O) a -R 28a -(O) b -Y 1 -R 29a ···(b21a) (In formula (b21a), Y 1 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. R 27a and R 28a are each an alkanediyl group having 2 to 6 carbon atoms which may be substituted with a halogen atom, or an arylene group having 6 to 20 carbon atoms which may be substituted with a halogen atom. R 29ais an alkyl group having 1 to 18 carbon atoms which may be substituted with a halogen atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms which may be substituted with a halogen atom, or an aralkyl group having 7 to 20 carbon atoms which may be substituted with a halogen atom. a and b are each 0 or 1, and at least one of a and b is 1.) Examples thereof include the group represented by

[0214] R 22a When the organic group as

[0215] R 22a has a halogen atom as a substituent, examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. When the organic group as is an alkyl group having 1 to 18 carbon atoms substituted with an alkylthio group, the number of carbon atoms of the alkylthio group is preferably 1 to 18. Examples of the alkylthio group having 1 to 18 carbon atoms include a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butylthio group, a sec-butylthio group, a tert-butylthio group, an isobutylthio group, an n-pentylthio group, an isopentylthio group, a tert-pentylthio group, an n-hexylthio group, an n-heptylthio group, an isoheptylthio group, a tert-heptylthio group, an n-octylthio group, an isooctylthio group, a tert-octylthio group, a 2-ethylhexylthio group, an n-nonylthio group, an n-decylthio group, an n-undecylthio group, an n-dodecylthio group, an n-tridecylthio group, an n-tetradecylthio group, an n-pentadecylthio group, an n-hexadecylthio group, an n-heptadecylthio group, and an n-octadecylthio group.

[0216] R 22a is an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may be substituted with a halogen atom and / or an alkylthio group, the aliphatic hydrocarbon group may contain an unsaturated double bond. In addition, the structure of the aliphatic hydrocarbon group is not particularly limited, and it may be linear, branched, cyclic, or a combination of these structures.

[0217] R 22a Preferable examples of the organic group as R when it is an alkenyl group include an allyl group and a 2-methyl-2-propenyl group.

[0218] R 22a Preferable examples of the organic group as R when it is an 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 isobutyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, an n-hexyl group, an n-hexan-2-yl group, an n-hexan-3-yl group, an n-heptyl group, an n-heptan-2-yl group, an n-heptan-3-yl group, an isoheptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a tert-octyl group, a 2-ethylhexyl group, an n-nonyl group, an isononyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, and an n-octadecyl group.

[0219] R 22a When the organic group as R is an alicyclic hydrocarbon group, examples of the alicyclic hydrocarbon constituting the main skeleton of the alicyclic hydrocarbon group include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, bicyclo[2.1.1]hexane, bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[2.2.2]octane, and adamantane. As the alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from these alicyclic hydrocarbons is preferable.

[0220] R 22aPreferable examples of the case where the organic group as an aliphatic hydrocarbon group substituted with a halogen atom include a trifluoromethyl group, a pentafluoroethyl group, a 2-chloroethyl group, a 2-bromoethyl group, a heptafluoro-n-propyl group, a 3-bromopropyl group, a nonafluoro-n-butyl group, a tridecafluoro-n-hexyl group, a heptadecafluoro-n-octyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 1,1-difluoro-n-propyl group, a 1,1,2,2-tetrafluoro-n-propyl group, a 3,3,3-trifluoro-n-propyl group, a 2,2,3,3,3-pentafluoro-n-propyl group, a 2-norbornyl-1,1-difluoroethyl group, a 2-norbornyl tetrafluoroethyl group, and a 3-adamantyl-1,1,2,2-tetrafluoropropyl group.

[0221] R 22a Preferable examples of the case where the organic group as an aliphatic hydrocarbon group substituted with an alkylthio group include a 2-methylthioethyl group, a 4-methylthio-n-butyl group, and a 2-n-butylthioethyl group.

[0222] R 22a Preferable examples of the case where the organic group as an aliphatic hydrocarbon group substituted with a halogen atom and an alkylthio group include a 3-methylthio-1,1,2,2-tetrafluoro-n-propyl group.

[0223] R 22a Preferable examples of the case where the organic group as an aryl group include a phenyl group, a naphthyl group, and a biphenylyl group.

[0224] R 22a Preferable examples of the case where the organic group as an aryl group substituted with a halogen atom include a pentafluorophenyl group, a chlorophenyl group, a dichlorophenyl group, and a trichlorophenyl group.

[0225] R 22aPreferable examples where the organic group as [the group in question] is an aryl group substituted with an alkylthio group include a 4-methylthiophenyl group, a 4-n-butylthiophenyl group, a 4-n-octylthiophenyl group, and a 4-n-dodecylthiophenyl group.

[0226] R 22a Preferable examples where the organic group as [the group in question] is an aryl group substituted with a halogen atom and an alkylthio group include a 1,2,5,6-tetrafluoro-4-methylthiophenyl group, a 1,2,5,6-tetrafluoro-4-n-butylthiophenyl group, and a 1,2,5,6-tetrafluoro-4-n-dodecylthiophenyl group.

[0227] R 22a Preferable examples where the organic group as [the group in question] is an aralkyl group include a benzyl group, a phenethyl group, a 2-phenylpropan-2-yl group, a diphenylmethyl group, and a triphenylmethyl group.

[0228] R 22a Preferable examples where the organic group as [the group in question] is an aralkyl group substituted with a halogen atom include a pentafluorophenylmethyl group, a phenyldifluoromethyl group, a 2-phenyltetrafluoroethyl group, and a 2-(pentafluorophenyl)ethyl group.

[0229] R 22a Preferable examples where the organic group as [the group in question] is an aralkyl group substituted with an alkylthio group include a p-methylthiobenzyl group.

[0230] R 22a Preferable examples where the organic group as [the group in question] is an aralkyl group substituted with a halogen atom and an alkylthio group include a 2-(2,3,5,6-tetrafluoro-4-methylthiophenyl)ethyl group.

[0231] R 22aPreferable examples where the organic group as such is an alkylaryl group include 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3-isopropylphenyl group, 4-isopropylphenyl group, 4-n-butylphenyl group, 4-isobutylphenyl group, 4-tert-butylphenyl group, 4-n-hexylphenyl group, 4-cyclohexylphenyl group, 4-n-octylphenyl group, 4-(2-ethyl-n-hexyl)phenyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4-di-tert-butylphenyl group, 2,5-di-tert-butylphenyl group, 2,6-di-tert-butylphenyl group, 2,4-di-tert-pentylphenyl group, 2,5-di-tert-pentylphenyl group, 2,5-di-tert-octylphenyl group, 2-cyclohexylphenyl group, 3-cyclohexylphenyl group, 4-cyclohexylphenyl group, 2,4,5-trimethylphenyl group, 2,4,6-trimethylphenyl group, 2,4,6-triisopropylphenyl group.

[0232] The group represented by formula (b21a) is a group containing an ether group. In formula (b21a), Y 1 Examples of the alkanediyl group having 1 to 4 carbon atoms represented by include methylene group, ethane-1,2-diyl group, ethane-1,1-diyl group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, butane-1,3-diyl group, butane-2,3-diyl group, butane-1,2-diyl group. In formula (b21a), R 27a or R 28aExamples of the alkane diyl group having 2 to 6 carbon atoms represented by include an ethane-1,2-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a butane-1,3-diyl group, a butane-2,3-diyl group, a butane-1,2-diyl group, a pentane-1,5-diyl group, a pentane-1,3-diyl group, a pentane-1,4-diyl group, a pentane-2,3-diyl group, a hexane-1,6-diyl group, a hexane-1,2-diyl group, a hexane-1,3-diyl group, a hexane-1,4-diyl group, a hexane-2,5-diyl group, a hexane-2,4-diyl group, and a hexane-3,4-diyl group.

[0233] In formula (b21a), R 27a or R 28a When is an alkane diyl group having 2 to 6 carbon atoms substituted with a halogen atom, examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. Examples of the alkane diyl group substituted with a halogen atom include a tetrafluoroethane-1,2-diyl group, a 1,1-difluoroethane-1,2-diyl group, a 1-fluoroethane-1,2-diyl group, a 1,2-difluoroethane-1,2-diyl group, a hexafluoropropane-1,3-diyl group, a 1,1,2,2,-tetrafluoropropane-1,3-diyl group, and a 1,1,2,2,-tetrafluoropentane-1,5-diyl group.

[0234] In formula (b21a), R 27a or R 28aExamples of the case where it is an arylene group include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, 2,5-dimethyl-1,4-phenylene group, biphenyl-4,4'-diyl group, diphenylmethane-4,4'-diyl group, 2,2-diphenylpropane-4,4'-diyl group, naphthalene-1,2-diyl group, naphthalene-1,3-diyl group, naphthalene-1,4-diyl group, naphthalene-1,5-diyl group, naphthalene-1,6-diyl group, naphthalene-1,7-diyl group, naphthalene-1,8-diyl group, naphthalene-2,3-diyl group, naphthalene-2,6-diyl group, naphthalene-2,7-diyl group.

[0235] In formula (b21a), R 27a or R 28a When it is an arylene group substituted with a halogen atom, examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. Examples of the arylene group substituted with a halogen atom include 2,3,5,6-tetrafluoro-1,4-phenylene group.

[0236] In formula (b21a), R 29a Examples of the alkyl group having 1 to 18 carbon atoms which may have a branch represented by include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, isobutyl group, n-pentyl group, isopentyl group, tert-pentyl group, n-hexyl group, n-hexan-2-yl group, n-hexan-3-yl group, n-heptyl group, n-heptan-2-yl group, n-heptan-3-yl group, isoheptyl group, tert-heptyl group, n-octyl group, isooctyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group.

[0237] In formula (b21a), R 29aWhen it is an alkyl group having 1 to 18 carbon atoms substituted with a halogen atom, examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. Examples of the alkyl group substituted with a halogen atom include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoro-n-propyl group, a nonafluoro-n-butyl group, a tridecafluoro-n-hexyl group, a heptadecafluoro-n-octyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 1,1-difluoro-n-propyl group, a 1,1,2,2-tetrafluoro-n-propyl group, a 3,3,3-trifluoro-n-propyl group, a 2,2,3,3,3-pentafluoro-n-propyl group, and a 1,1,2,2-tetrafluorotetradecyl group.

[0238] In formula (b21a), R 29a When it is an alicyclic hydrocarbon group having 3 to 12 carbon atoms, examples of the alicyclic hydrocarbon constituting the main skeleton of the alicyclic hydrocarbon group include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, bicyclo[2.1.1]hexane, bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[2.2.2]octane, and adamantane. As the alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from these alicyclic hydrocarbons is preferable.

[0239] In formula (b21a), R 29a When it is an aryl group, a halogenated aryl group, an aralkyl group, or a halogenated aralkyl group, preferable examples of these groups are the same as those when R 22a is these groups.

[0240] Among the groups represented by formula (b21a), a preferable group is a group in which the carbon atom bonded to the sulfur atom in the group represented by R 27a is substituted with a fluorine atom. The number of carbon atoms of such a preferable group is preferably 2 or more and 18 or less.

[0241] R 22aAs the group, a perfluoroalkyl group having 1 to 8 carbon atoms is preferable. In addition, since it is easy to form a high-definition resist pattern, a camphor-10-yl group is also preferable as R 22a as well.

[0242] In formula (b21), R 23a ~R 26a is a hydrogen atom or a monovalent organic group. Also, R 23a and R 24a and R 24a and R 25a or R 25a and R 26a may each be bonded to each other to form a ring. For example, R 24a and R 25a may be bonded to form a 5-membered ring together with a naphthalene ring to form an acenaphthene skeleton.

[0243] As the monovalent organic group, an alicyclic hydrocarbon group, a heterocyclic group (heterosilyl group), or an alkyl group having 4 to 18 carbon atoms which may be substituted with a halogen atom and may have a branch, an alkoxy group; a heterosilyloxy group; an alicyclic hydrocarbon group, a heterocyclic group (heterosilyl group), or an alkylthio group having 4 to 18 carbon atoms which may be substituted with a halogen atom and may have a branch; a heterosilylthio group; is preferable. In addition, a group in which a methylene group at an arbitrary position not adjacent to the oxygen atom of the alkoxy group is substituted with -CO- is also preferable. A group in which the alkoxy group is interrupted by an -O-CO- bond or an -O-CO-NH- bond is also preferable. Note that the left end of the -O-CO- bond and the -O-CO-NH- bond is on the side closer to the naphthoic acid mother nucleus in the alkoxy group. Furthermore, an alkylthio group having 4 to 18 carbon atoms which may be substituted with an alicyclic hydrocarbon group, a heterocyclic group, or a halogen atom and may have a branch is also preferable as R 23a ~R 26a as well. A group in which a methylene group at an arbitrary position not adjacent to the sulfur atom of the alkylthio group is substituted with -CO- is also preferable. A group in which the alkylthio group is interrupted by an -O-CO- bond or an -O-CO-NH- bond is also preferred. Note that the left ends of the -O-CO- bond and the -O-CO-NH- bond are on the side closer to the naphthoic acid nucleus in the alkylthio group.

[0244] R 23a ~R 26a As, R 23a is an organic group, and R 24a ~R 26a is a hydrogen atom, or R 24a is an organic group, and R 23a , R 25a , and R 26a are preferably hydrogen atoms. Also, R 23a ~R 26a may all be hydrogen atoms.

[0245] R 23a ~R 26a Examples of the case where R

[0246] R 23a ~R 26aExamples where it is an unsubstituted alkoxy group include n-butyloxy group, sec-butyloxy group, tert-butyloxy group, isobutyloxy group, n-pentyloxy group, isopentyloxy group, tert-pentyloxy group, n-hexyloxy group, n-heptyloxy group, isoheptyloxy group, tert-heptyloxy group, n-octyloxy group, isooctyloxy group, tert-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-dodecyloxy group, n-tridecyloxy group, n-tetradecyloxy group, n-pentadecyloxy group, n-hexadecyloxy group, n-heptadecyloxy group, n-octadecyloxy group.

[0247] R 23a ~R 26a Examples where it is an unsubstituted alkylthio group include n-butylthio group, sec-butylthio group, tert-butylthio group, isobutylthio group, n-pentylthio group, isopentylthio group, tert-pentylthio group, n-hexylthio group, n-heptylthio group, isoheptylthio group, tert-heptylthio group, n-octylthio group, isooctylthio group, tert-octylthio group, 2-ethylhexylthio group, n-nonylthio group, n-decylthio group, n-undecylthio group, n-dodecylthio group, n-tridecylthio group, n-tetradecylthio group, n-pentadecylthio group, n-hexadecylthio group, n-heptadecylthio group, n-octadecylthio group.

[0248] R 23a ~R 26aWhen it is an alkyl group, an alkoxy group, or an alkylthio group substituted with an alicyclic hydrocarbon group, examples of the alicyclic hydrocarbon constituting the main skeleton of the alicyclic hydrocarbon group include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, bicyclo[2.1.1]hexane, bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[2.2.2]octane, and adamantane. As the alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from these alicyclic hydrocarbons is preferable.

[0249] R 23a ~R 26a When it is an alkyl group, an alkoxy group, or an alkylthio group substituted with a heterocyclic group, or R 23a ~R 26a When it is a heterocyclyloxy group, examples of the heterocyclic ring constituting the main skeleton of the heterocyclic group or the heterocyclyloxy group include pyrrole, thiophene, furan, pyran, thiopyran, imidazole, pyrazole, thiazole, isothiazole, oxazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, pyrrolidine, pyrazolidine, imidazolidine, isoxazolidine, isothiazolidine, piperidine, piperazine, morpholine, thiomorpholine, chroman, thiochroman, isochroman, isothiochroman, indoline, isoindoline, pyrindine, indolizine, indole, indazole, purine, quinolidine, isoquinoline, quinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, perimidine, phenanthroline, carbazole, carboline, phenazine, antiridine, thiadiazole, oxadiazole, triazine, triazole, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzothiadiazole, benzofuroxan, naphthimidazole, benzotriazole, tetraazaindene. In addition, a saturated heterocyclic ring obtained by hydrogenating a ring having a conjugated bond among these heterocyclic rings is also preferable. As the heterocyclic group that substitutes an alkyl group, an alkoxy group or an alkylthio group, or the heterocyclic group contained in a heterocyclyloxy group, a group obtained by removing one hydrogen atom from the above heterocycle is preferable.

[0250] R 23a ~R 26a Examples of the case where R 23a ~R 26a is an alkoxy group containing an alicyclic hydrocarbon group include cyclopentyloxy group, methylcyclopentyloxy group, cyclohexyloxy group, fluorocyclohexyloxy group, chlorocyclohexyloxy group, cyclohexylmethyloxy group, methylcyclohexyloxy group, norbornyloxy group, ethylcyclohexyloxy group, cyclohexylethyloxy group, dimethylcyclohexyloxy group, methylcyclohexylmethyloxy group, norbornylmethyloxy group, trimethylcyclohexyloxy group, 1-cyclohexylbutyloxy group, adamantyloxy group, menthyloxy group, n-butylcyclohexyloxy group, tert-butylcyclohexyloxy group, bornyloxy group, isobornyloxy group, decahydronaphthyloxy group, dicyclopentadienooxy group, 1-cyclohexylpentyloxy group, methyladamantyloxy group, adamantylmethyloxy group, 4-pentylcyclohexyloxy group, cyclohexylcyclohexyloxy group, adamantylethyloxy group, dimethyladamantyloxy group.

[0251] R 23a ~R 26a Examples of the case where R 23a ~R 26a is a heterocyclyloxy group include tetrahydrofuranyloxy group, furfuryloxy group, tetrahydrofurfuryloxy group, tetrahydropyranyloxy group, butyrolactonyloxy group, indryloxy group.

[0252] R 23a ~R 26a Examples of the case where R 23a ~R 26a is an alkylthio group containing an alicyclic hydrocarbon group include cyclopentylthio group, cyclohexylthio group, cyclohexylmethylthio group, norbornylthio group, isonorbornylthio group.

[0253] R 23a ~R 26a Examples of the case where ~R is a heterocyclic thio group include a furfuryl thio group and a tetrahydrofuranyl thio group.

[0254] R 23a ~R 26a Examples of the case where ~R is a group in which a methylene group at any position not adjacent to the oxygen atom of the alkoxy group is substituted with -CO- include a 2-ketobutyl-1-oxy group, a 2-ketopentyl-1-oxy group, a 2-ketohexyl-1-oxy group, a 2-ketoheptyl-1-oxy group, a 2-ketooctyl-1-oxy group, a 3-ketobutyl-1-oxy group, a 4-ketopentyl-1-oxy group, a 5-ketohexyl-1-oxy group, a 6-ketoheptyl-1-oxy group, a 7-ketooctyl-1-oxy group, a 3-methyl-2-ketopentan-4-oxy group, a 2-ketopentan-4-oxy group, a 2-methyl-2-ketopentan-4-oxy group, a 3-ketoheptan-5-oxy group, and a 2-adamantanone-5-oxy group.

[0255] R 23a ~R 26a Examples of the case where ~R is a group in which a methylene group at any position not adjacent to the sulfur atom of the alkylthio group is substituted with -CO- include a 2-ketobutyl-1-thio group, a 2-ketopentyl-1-thio group, a 2-ketohexyl-1-thio group, a 2-ketoheptyl-1-thio group, a 2-ketooctyl-1-thio group, a 3-ketobutyl-1-thio group, a 4-ketopentyl-1-thio group, a 5-ketohexyl-1-thio group, a 6-ketoheptyl-1-thio group, a 7-ketooctyl-1-thio group, a 3-methyl-2-ketopentan-4-thio group, a 2-ketopentan-4-thio group, a 2-methyl-2-ketopentan-4-thio group, and a 3-ketoheptan-5-thio group.

[0256] Specific examples of the compound represented by the formula (b21) include the following compounds.

[0257]

Chemical formula

[0258]

Chem.

[0259]

Chem.

[0260]

Chem.

[0261]

Chem.

[0262]

Chem.

[0263]

Chem.

[0264]

Chem.

[0265]

Chem.

[0266]

Chem.

[0267] The photoacid generator (B) may be used alone or in combination of two or more. Also, the content of the photoacid generator (B) is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 6% by mass or less, and particularly preferably 0.5% by mass or more and 6% by mass or less, based on the total solid content of the photosensitive resin composition. By setting the amount of the photoacid generator (B) used within the above range, it is easy to prepare a photosensitive resin composition having good sensitivity, being a uniform solution, and having excellent storage stability.

[0268] <Acid diffusion controller (C)> The photosensitive resin composition preferably contains an acid diffusion inhibitor (C). The acid diffusion inhibitor (C) is not particularly limited. The acid diffusion inhibitor (C) can improve the shape of the resist pattern, the standing stability of the photosensitive resin composition layer, etc.

[0269] Examples of the acid diffusion controller (C) include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tri-n-pentylamine (triamylamine), tribenzylamine, diethanolamine, triethanolamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3,-tetramethylurea, 1,3-diphenylurea, imidazole, benzimidazole, 4-methylimidazole, 8-hydroxyquinoline, acridine, purine, pyrrolidine, piperidine, 4-hydroxy-pentamethylpiperidine, 2,4,6-tri(2-pyridyl)-S-triazine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, pyridine, 2,6-di-tert-butylpyridine and the like. These may be used alone or in combination of two or more kinds.

[0270] The acid diffusion controller (C) is preferably used in the range of 0.01 part by mass or more and 3 parts by mass or less, more preferably in the range of 0.05 part by mass or more and 1 part by mass or less, based on 100 parts by mass of the resin (A).

[0271] <Solvent (S)> The photosensitive resin composition contains a solvent (S). The type of the solvent (S) is not particularly limited as long as it does not inhibit the object of the present invention, and it can be appropriately selected from organic solvents conventionally used in photosensitive resin compositions and used.

[0272] Specific examples of the solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone; polyhydric alcohols such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, monophenyl ether of dipropylene glycol monoacetate, etc., and their derivatives; cyclic ethers such as dioxane; esters such as ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, etc.; aromatic hydrocarbons such as toluene, xylene, etc. These may be used alone or in combination of two or more.

[0273] The content of the solvent (S) is not particularly limited as long as it does not inhibit the object of the present invention. It is preferable to use the solvent (S) in a range where the solid content concentration of the photosensitive resin composition is 1% by mass or more and 50% by mass or less, 3% by mass or more and 30% by mass or less, or 5% by mass or more and 20% by mass or less.

[0274] <Other components> The photosensitive resin composition may further contain a polyvinyl resin in order to improve the plasticity of the formed film. Specific examples of the polyvinyl resin include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoic acid, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl phenol, and copolymers thereof.

[0275] The photosensitive resin composition may further contain an adhesion promoter in order to improve the adhesion to the support.

[0276] The photosensitive resin composition may further contain a surfactant in order to improve coating properties, defoaming properties, leveling properties, etc. Specific examples of the surfactant include BM-1000, BM-1100 (both manufactured by BM Chemical Co., Ltd.), 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 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 Silicone 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 Inc.), and other commercially available fluorine-based surfactants, but are not limited thereto.

[0277] The photosensitive resin composition may further contain an acid or an acid anhydride in order to finely adjust the solubility in the developer.

[0278] Specific examples of the acid and acid anhydride include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, cinnamic acid; hydroxy monocarboxylic acids such as lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid, syringic acid; polycarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, butanetetracarboxylic acid, trimellitic acid, pyromellitic acid, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid; acid anhydrides such as itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarballylic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hymic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bisanhydrotrimellitate, glycerin trisanhydrotrimellitate; and the like.

[0279] <Method for preparing photosensitive resin composition> The photosensitive resin composition is prepared by mixing and stirring the above components in a conventional manner. Examples of the apparatus that can be used for mixing and stirring the above components include a dissolver, a homogenizer, a three-roll mill, etc. After uniformly mixing the above components, the resulting mixture may be further filtered using a mesh, a membrane filter, etc.

[0280] ≪Method for manufacturing microlens≫ The method for manufacturing a microlens includes a step of applying a photosensitive resin composition onto a lens material layer to form a photosensitive resin composition layer (coating film) (hereinafter also referred to as the coating step), a step of selectively exposing the photosensitive resin composition layer (hereinafter also referred to as the exposure step), a step of developing the exposed photosensitive resin composition layer (hereinafter also referred to as the development step), a step of heating the developed photosensitive resin composition layer to form a mask layer having a microlens pattern (hereinafter also referred to as the mask layer formation step), and a step of dry-etching the lens material layer and the mask layer to transfer the shape of the microlens pattern to the lens material layer (hereinafter also referred to as the shape transfer step).

[0281] [Coating Step] In the coating step, a photosensitive resin composition is applied onto the lens material layer to form a photosensitive resin composition layer.

[0282] As the lens material layer, a lens material layer having an etching rate of 110 nm / min or more by plasma obtained from CF 4 gas is preferable, and a lens material layer having an etching rate of 140 nm / min or more is more preferable. The upper limit of the etching rate is, for example, 250 nm / min or less, or 200 nm / min or less. Since the etching rate of the mask layer obtained by using the above photosensitive resin composition is relatively fast, even a lens material layer within the above numerical range can easily transfer the shape of the desired lens pattern. In this specification, the etching rate means the etching rate when CF 4 plasma etching is performed under the conditions described in the examples below. Examples of the polymer used for the lens material layer within the above numerical range include polymers having a triazine skeleton.

[0283] The method for forming the photosensitive resin composition layer is not particularly limited, and conventionally known methods can be used. When the photosensitive resin composition is a solid or a high-viscosity gel, for example, after supplying a predetermined amount of the photosensitive resin composition onto the lens material layer, the photosensitive resin composition layer can be formed by pressing the photosensitive resin composition while appropriately heating it. When the photosensitive resin composition is a liquid (for example, when the photosensitive resin composition contains a solvent (S)), for example, using a contact transfer type coating device such as a roll coater, a reverse coater, a bar coater, a slit coater, or a non-contact type coating device such as a spinner (rotary coating device), a curtain flow coater, etc., the photosensitive resin composition is applied onto the lens material layer to a desired film thickness, and by appropriately performing a heat treatment (pre-bake (post-apply bake (PAB)) treatment) to remove the organic solvent, the photosensitive resin composition layer can be formed.

[0284] The conditions of the above heat treatment vary depending on the types of components in the photosensitive resin composition, the blending ratio, the coating film thickness, etc. The heating temperature is, for example, 60 to 150 °C (preferably 70 to 140 °C), and the heating time is, for example, about 0.5 to 60 minutes (preferably 1 to 50 minutes). The film thickness of the photosensitive resin composition layer is preferably in the range of 100 nm to 4.0 μm, more preferably 200 nm to 2.0 μm.

[0285] <Exposure step> In the exposure step, the photosensitive resin composition layer is selectively exposed. Selective exposure can be performed, for example, through a desired mask pattern. Exposure can be performed using a KrF excimer laser or an ArF excimer laser. Also, by appropriately adjusting the composition of the photosensitive resin composition, exposure can also be performed using radiation such as F 2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc.

[0286] After exposure, PEB treatment (post-exposure heat treatment) is appropriately performed. The conditions of the PEB treatment vary depending on the type, blending ratio, coating film thickness, etc. of each component in the composition. For example, the heating temperature is 60 to 150 °C (preferably 70 to 140 °C), and the heating time is, for example, about 0.5 to 60 minutes (preferably 1 to 50 minutes).

[0287] [Development process] In the development process, the exposed positive photosensitive resin composition layer is developed. Thereby, unnecessary portions are dissolved and removed.

[0288] As the developer, for example, an aqueous solution of alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane can be used. Also, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the above aqueous solution of alkalis can be used as the developer. As the developer, a 0.1 to 10 mass% aqueous solution of tetramethylammonium hydroxide is preferred.

[0289] The development time also varies depending on the composition of the photosensitive resin composition and the film thickness of the photosensitive resin composition layer, etc., but is usually 1 to 30 minutes. The development method may be any of a puddle method, a dipping method, a paddle method, a spray development method, etc.

[0290] After development, running water washing is appropriately performed for 30 to 90 seconds, and drying is performed using an air gun, an oven, or the like.

[0291] [Mask layer formation process] In the mask layer formation step, the photosensitive resin composition layer after development is heated to form a mask layer having a microlens pattern.

[0292] The heating conditions vary depending on the types of components, blending ratios, coating film thickness, etc. in the photosensitive resin composition. For example, the heating temperature is 130 to 170 °C (preferably 140 to 160 °C), and the heating time is, for example, about 1 to 30 minutes (preferably 3 to 10 minutes).

[0293] <Shape transfer step> In the shape transfer step, the lens material layer and the mask layer are dry-etched to transfer the shape of the microlens pattern to the lens material layer. Thereby, microlenses can be obtained from the lens material layer.

[0294] The dry etching is not particularly limited, and examples thereof include dry etching by plasma (oxygen, argon, CF 4 etc.), corona discharge, etc. In performing this step, it is preferable to adjust the ratio of the etching rate of the mask layer to the lens material layer to be in the range of 0.75 to 1.25. By performing such adjustment, it becomes easier to transfer the shape of the desired lens pattern. The preferable range of the etching rate of the mask layer is the same as that of the lens material layer described above.

Examples

[0295] The present invention will be described in more detail based on the examples, but the present invention is not limited by these examples.

[0296] [Examples 1 to 5, Comparative Example 1 and Comparative Example 2] The components of the types and amounts described in Table 1 were uniformly dissolved in a solvent so that the solid content concentration became 8% by mass to prepare a photosensitive resin composition. The numerical values in the composition in Table 1 represent the blending amounts (unit: parts by mass) of the respective components. As the solvent, a mixed solvent having a mass ratio of 60:40 of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether was used. Further, the components used in the examples and comparative examples are as shown below.

[0297] A-1: Resin represented by the following formula (weight average molecular weight Mw: 12000, dispersity: 1.66, x = 30, y = 50, z = 20, Onishi parameter: 3.734, ring parameter: 0.421)

Chemical formula

[0298] A-2: Resin represented by the following formula (weight average molecular weight Mw: 12000, dispersity: 1.54, x = 50, y = 50, Onishi parameter: 4.167, ring parameter: 0.319)

Chemical formula

[0299] A-3: Resin represented by the following formula (weight average molecular weight Mw: 6000, dispersity: 1.66, x = 30, y = 50, z = 20, Onishi parameter: 3.734, ring parameter: 0.421)

Chemical formula

[0300] A-4: Resin represented by the following formula (weight average molecular weight Mw: 20000, dispersity: 1.10, x = 35, y = 65, Onishi parameter: 2.693, ring parameter: 0.495)

Chemical formula

[0301] A-5: Resin represented by the following formula (weight average molecular weight Mw: 6000, dispersity: 2.62, x = 40, y = 60, Onishi parameter: 4.077, ring parameter: 0.207)

Chem.

[0302] B-1: Compound represented by the following formula

Chem.

[0303] B-2: Compound represented by the following formula

Chem.

[0304] B-3: Compound represented by the following formula

Chem.

[0305] C-1: Compound represented by the following formula

Chem.

[0306] C-2: Compound represented by the following formula

Chem.

[0307] <Evaluation> The photosensitive resin compositions obtained in the examples and comparative examples were evaluated according to the following items.

[0308] (KrF patterning) On a substrate having an antireflection film (film thickness: 0.16 μm) and an organic underlayer film (film thickness: 1.0 μm) formed on a Si substrate, a photosensitive resin composition prepared in an example or a comparative example was applied using a spinner to form a coating film. With respect to the above coating film, prebaking treatment was performed at 100 °C for 60 seconds on a hot plate to dry the coating film, thereby forming a photosensitive resin composition layer with a film thickness of 300 nm. Next, using a KrF exposure apparatus NSR-S203B (manufactured by Nikon Corporation, NA = 0.68, S = 0.75), a KrF excimer laser (wavelength: 248 nm) was selectively irradiated onto the photosensitive resin composition layer through a mask (dot: 0.42 μm × 0.42 μm, space: 0.22 μm). The exposure amount here was 50 mJ / cm 2 was set. Thereafter, with respect to the photosensitive resin composition layer, PEB treatment was performed at 120 °C for 90 seconds, and then development was performed for 60 seconds with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide at 23 °C. Those in which a pattern was formed under such conditions were designated as A, and those in which no pattern was formed were designated as B. The results are shown in Table 1.

[0309] (ArF patterning) On a substrate having an antireflection film (film thickness: 0.16 μm) and an organic underlayer film (film thickness: 1.0 μm) formed on a Si substrate, a photosensitive resin composition prepared in an example or a comparative example was applied using a spinner to form a coating film. With respect to the above coating film, prebaking treatment was performed at 120 °C for 60 seconds on a hot plate to dry the coating film, thereby forming a photosensitive resin composition layer with a film thickness of 200 nm. Next, using an ArF exposure apparatus NSR-S308F (manufactured by Nikon Corporation, NA = 0.60, S = 0.75), an ArF excimer laser (wavelength: 193 nm) was selectively irradiated onto the photosensitive resin composition layer through a mask (dot: 0.4 μm × 0.4 μm, space: 0.2 μm). The exposure amount here was 10 mJ / cm 2 was set. Thereafter, the photosensitive resin composition layer was subjected to PEB treatment at 110°C for 60 seconds, and then developed at 23°C for 65 seconds with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. Those in which patterns were formed under such conditions were designated as A, and those in which no patterns were formed were designated as B. The results are shown in Table 1.

[0310] (Etching rate) On a Si substrate, using a spinner, the photosensitive resin composition prepared in the example or comparative example was applied to form a coating film. With respect to the above coating film, pre-baking treatment was performed on a hot plate at 100°C for 60 seconds to dry the coating film, thereby forming a photosensitive resin composition layer with a film thickness of 1 μm.

[0311] For this photosensitive resin composition layer, under the following conditions, CF 4 dry etching (CF 4 plasma etching) was performed using the plasma obtained from the gas. <CF 4 Plasma etching conditions Apparatus: High-vacuum RIE apparatus (TCA-3822 manufactured by Tokyo Ohka Kogyo Co., Ltd.) Gas: CF 4 Gas Gas flow rate: 300 mL / min Temperature inside the chamber: 60°C Pressure inside the chamber: 40 Pa Output power (RF) applied to generate plasma: 800 W Processing time: 2 minutes, 3 minutes, 5 minutes, or 7 minutes

[0312] From the difference in the film thickness of the photosensitive resin composition layer before and after etching, the etching rate (the thickness of the film etched per unit time) was determined. Using this etching rate as an index, evaluation was performed according to the following criteria. The results are shown in Table 1. A + : Etching rate exceeds 140 nm / min A: Etching rate exceeds 120 nm / min and is 140 nm / min or less B: Etching rate is 120 nm / min or less

[0313] (Thermal flow property) Regarding the pattern formed in the above evaluation of KrF patterning, post-bake treatment was performed for 300 seconds at each temperature. The cross-section of the pattern was observed by SEM, the lowest temperature at which the microlens pattern shape could be obtained was determined, and evaluation was carried out according to the following criteria. The results are shown in Table 1. In Comparative Example 2, since no pattern was formed in KrF patterning, the evaluation of thermal flow property was not performed. A: 140°C or higher and 170°C or lower B: 110°C or higher and less than 140°C, or higher than 170°C and 200°C or lower C: Less than 110°C, or higher than 200°C

[0314]

Table 1

[0315] As shown in Table 1, it can be seen that a photosensitive resin composition containing a resin (A) having a specific structural unit, a photoacid generator (B), and a solvent (S) can form a fine microlens pattern with a high etching rate using a KrF excimer laser or an ArF excimer laser. Therefore, it can be seen that the above photosensitive resin composition is suitable for use in forming a microlens pattern as a mask layer for dry etching on a lens material layer.

Claims

1. A photosensitive resin composition used for forming a microlens pattern as a mask layer for dry etching on a lens material layer, wherein the photosensitive resin composition contains a resin (A), a photoacid generator (B), and a solvent (S), the resin (A) is derived from (meth)acrylic acid ester, contains an acid-dissociable dissolution inhibiting group, and has a structural unit (a1) in which the solubility in alkali increases by the action of an acid and a structural unit (a2) containing a residue suppressing group, the photosensitive resin composition.

2. The photosensitive resin composition according to claim 1, wherein the structural unit (a1) is a structural unit represented by any one of the following formulas (a1-1) to (a1-3). 【Chemical 1】 (In Formulas (a1-1) to (a1-3), R １４ｂ , and R １８ｂ to R ２３ｂ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, or a linear or branched fluorinated alkyl group having 1 to 6 carbon atoms, and R １５ｂ to R １７ｂ each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched fluorinated alkyl group having 1 to 6 carbon atoms, or an aliphatic cyclic group having 5 to 20 carbon atoms, and R １６ｂ and R １７ｂ may be bonded to each other to form a hydrocarbon ring having 5 to 20 carbon atoms together with the carbon atom to which both are bonded, Y ｂ represents an aliphatic cyclic group or an alkyl group which may have a substituent, p represents an integer of 0 or more and 4 or less, and q represents 0 or 1.)

3. The residue-inhibiting group is a lactone-containing cyclic group or a -SO ２ -containing cyclic group, and the photosensitive resin composition according to claim 1 or 2.

4. A step of applying the photosensitive resin composition according to claim 1 or 2 on a lens material layer to form a coating film, a step of selectively exposing the coating film in a position, a step of developing the exposed coating film, a step of heating the developed coating film to form a mask layer having a microlens pattern, and a step of dry etching the lens material layer and the mask layer to transfer the shape of the microlens pattern to the lens material layer, a method for manufacturing a microlens.

5. The method for manufacturing a microlens according to claim 4, wherein the coating film is exposed by a KrF excimer laser or an ArF excimer laser.

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