Photosensitive resin composition and method for manufacturing microlens

Abstract

The invention relates to a photosensitive resin composition and a method for producing a microlens. The present invention addresses the problem of providing: 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 producing a microlens. The solution of the present invention is a photosensitive resin composition for forming a microlens pattern as a mask layer for dry etching on a lens material layer, the photosensitive resin composition containing a resin (A), a photoacid generator (B), and a solvent (S), the resin (A) has: a structural unit (a1) which is derived from a (meth) acrylate, contains an acid-dissociable dissolution-inhibiting group, and has solubility in a base that can be increased by the action of an acid; and a structural unit (a2) containing a residue-inhibiting group.

Description

Technical Field

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

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

[0003] In forming the microlens, a method called the heat flow method and a method called the etching method have been widely used industrially.

[0004] In the former heat flow method, a photoresist film (a layer made 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 performed in sequence, whereby a concavo-convex pattern is formed on the element. By heating this concavo-convex pattern at a temperature above the glass transition temperature to make it flow, a hemispherical microlens pattern is formed by surface tension (for example, see Patent Document 1).

[0005] On the other hand, in the latter etching method, after a positive photosensitive resin composition layer is formed on a lens material layer using a positive photosensitive resin composition, it is selectively exposed. Then, after the exposed portion is removed by development, the positive photosensitive resin composition layer is made to flow 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, whereby a microlens can be obtained.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009-20462 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] However, in recent years, there has been a tendency for further high-definition of CCD image sensors and CMOS image sensors. Therefore, as a photosensitive resin composition, it is required to be able to form a fine microlens pattern.

[0011] In addition, with the increasing fineness of image sensors, the wavelength of the light irradiated onto the photosensitive resin composition has gradually become shorter. More specifically, it has been gradually proposed to stagewise shift from the exposure conditions under i-line (wavelength: 365 nm), which has been widely used in the past, to the exposure conditions under KrF excimer laser (wavelength: 248 nm) or ArF excimer laser (wavelength: 193 nm).

[0012] In addition, in the etching method, when using a lens material layer with a high etching rate, in order to transfer the micro-lens pattern with a good shape, it is required to be able to form a micro-lens pattern with a high etching rate corresponding to the lens material layer.

[0013] The present invention has been made in view of the above circumstances, and its object is to provide a photosensitive resin composition and a method for manufacturing a microlens, wherein the photosensitive resin composition can form a fine and high-etching-rate microlens pattern as a dry-etching mask layer using a KrF excimer laser or an ArF excimer laser.

[0014] Means for Solving the Problem

[0015] To solve the above problems, the inventors of the present application repeatedly conducted in-depth research, and as a result, found that if it is a photosensitive resin composition containing a resin, a photoacid generator, and a solvent having specific structural units, the above problems can be solved, thereby completing the present invention. Specifically, the present invention provides the following aspects.

[0016] [1] A photosensitive resin composition for forming a microlens pattern as a dry-etching mask layer on a lens material layer.

[0017] The above photosensitive resin composition contains a resin (A), a photoacid generator (B), and a solvent (S).

[0018] The above resin (A) has: a structural unit (a1) derived from (meth)acrylate, containing an acid-dissociable dissolution-inhibiting group and having solubility in an alkali that can be increased by the action of an acid; and a structural unit (a2) containing a residue-inhibiting group.

[0019] [2] The photosensitive resin composition according to [1], wherein the above structural unit (a1) is a structural unit represented by any one of the following formulas (a1-1) to (a1-3).

[0020] [Chemical Formula 1]

[0021]

[0022] (In formulas (a1-1) to (a1-3), R 14b and R 18b to R 23bEach 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 fluoroalkyl group having 1 to 6 carbon atoms, R 15b ~R 17b Each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched fluoroalkyl 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, together with the carbon atom to which both are bonded, a hydrocarbon ring having 5 to 20 carbon atoms, 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.)

[0023] [3] The photosensitive resin composition according to [1] or [2], wherein the residue-inhibiting group is a cyclic group containing a lactone or a cyclic group containing -SO 2 -.

[0024] [4] A method for manufacturing a microlens, comprising the following steps:

[0025] A step of forming a coating film by coating the photosensitive resin composition according to any one of [1] to [3] on a lens material layer;

[0026] A step of selectively exposing the coating film;

[0027] A step of developing the exposed coating film;

[0028] A step of heating the developed coating film to form a mask layer having a microlens pattern; and

[0029] 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.

[0030] [5] The method for manufacturing a microlens according to [4], wherein the coating film is exposed using a KrF excimer laser or an ArF excimer laser.

[0031] Advantages of the Invention

[0032] According to the present invention, a photosensitive resin composition and a method for manufacturing a microlens can be provided, and the photosensitive resin composition can form a fine microlens pattern with a high etching rate as a dry-etching mask layer using a KrF excimer laser or an ArF excimer laser. Detailed Description of the Invention

[0033] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to any of the following embodiments and can be appropriately modified and implemented within the scope of the object of the present invention.

[0034] 《Photosensitive Resin Composition》

[0035] The photosensitive resin composition is used to form a microlens pattern as a dry-etching mask layer on a lens material layer. The photosensitive resin composition contains a resin (A), a photoacid generator (B), and a solvent (S). The resin (A) has: a structural unit (a1) derived from (meth)acrylate, containing an acid-dissociable dissolution-inhibiting group and having solubility in an alkali that can be increased by the action of an acid; and a structural unit (a2) containing a residue-inhibiting group.

[0036] <Resin (A)>

[0037] The resin (A) has: a structural unit (a1) derived from (meth)acrylate, containing an acid-dissociable dissolution-inhibiting group and having solubility in an alkali that can be increased by the action of an acid; and a structural unit (a2) containing a residue-inhibiting group.

[0038] By using such a resin (A), it is possible to form a fine and high-etching-rate microlens pattern as a dry-etching mask layer using a KrF excimer laser or an ArF excimer laser.

[0039] In addition, in the formation of the microlens pattern of the mask layer, heat treatment is often performed in a set temperature range of about 150°C. By using the resin (A), a microlens pattern can be formed by heat treatment at about 150°C, and thus a photosensitive resin composition with excellent heat fluidity can be obtained.

[0040] [Structural Unit (a1)]

[0041] As the structural unit (a1), there is no particular limitation as long as it is a structural unit that has been conventionally known as a structural unit derived from (meth)acrylate, containing an acid-dissociable dissolution-inhibiting group and having solubility in an alkali that can be increased by the action of an acid.

[0042] As the structural unit (a1), it is preferably a structural unit represented by any one of the following formulas (a1-1) to (a1-3).

[0043] [Chemical Formula 2]

[0044]

[0045] In the above formulas (a1-1) to (a1-3), R 14b and R 18b ~R 23bEach 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 fluoroalkyl group having 1 to 6 carbon atoms, R 15b ~R 17b Each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched fluoroalkyl 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.

[0046] It should be noted that examples of the linear or branched alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl and the like. In addition, the fluoroalkyl group is a group obtained by substituting part or all of the hydrogen atoms of the above alkyl group with fluorine atoms.

[0047] Specific examples of the aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as monocyclic alkanes, bicyclic alkanes, tricyclic alkanes, and tetracyclic alkanes. Specifically, groups obtained by removing one hydrogen atom from monocyclic alkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be mentioned. Particularly preferred are groups obtained by removing one hydrogen atom from cyclohexane and adamantane (which may further have a substituent).

[0048] In the case where R 16b and R 17b do not bond to each other to form a hydrocarbon ring, as the above R 15b , R 16b and R 17b , from the viewpoint of high contrast and good resolution, depth of focus amplitude, etc., a linear or branched alkyl group having 1 to 4 carbon atoms is preferred. As the above R 19b , R 20b , R 22b , R 23b , a hydrogen atom or a methyl group is preferred.

[0049] The above R 16b and R 17bIt may form, together with the carbon atom to which both are bonded, an aliphatic cyclic group having 5 to 20 carbon atoms. Specific examples of such an aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as monocyclic alkanes, bicyclic alkanes, tricyclic alkanes, and tetracyclic alkanes. Specifically, groups obtained by removing one or more hydrogen atoms from monocyclic alkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. Particularly preferred are groups obtained by removing one or more hydrogen atoms from cyclopentane, cyclohexane, or adamantane (which may further have substituents).

[0050] In addition, in the case where the aliphatic cyclic group formed by the above R 16b and R 17b has a substituent on its ring skeleton, examples of such a substituent include polar groups such as a hydroxyl group, a carboxyl group, a cyano group, and 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 preferred.

[0051] The above Y b is an aliphatic cyclic group or an alkyl group, and examples include groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as monocyclic alkanes, bicyclic alkanes, tricyclic alkanes, and tetracyclic alkanes. Specifically, groups obtained by removing one or more hydrogen atoms from monocyclic alkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. Particularly preferred are groups obtained by removing one or more hydrogen atoms from adamantane (which may further have substituents).

[0052] In addition, in the case where the aliphatic cyclic group of the above Y b has a substituent on its ring skeleton, examples of such a substituent include polar groups such as a hydroxyl group, a carboxyl group, a cyano group, and 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 preferred.

[0053] In addition, when Y b is an alkyl group, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 6 to 15 carbon atoms, is preferred. Such an alkyl group is particularly preferably an alkoxyalkyl group, and examples of such an alkoxyalkyl group include 1-methoxyethyl, 1-ethoxyethyl, 1-n-propoxyethyl, 1-isopropoxyethyl, 1-n-butoxyethyl, 1-isobutoxyethyl, 1-tert-butoxyethyl, 1-methoxypropyl, 1-ethoxypropyl, 1-methoxy-1-methyl-ethyl, 1-ethoxy-1-methyl ethyl, etc.

[0054] As a preferable specific example of the structural unit represented by the above formula (a1-1), the structural units represented by the following formulas (a1-1-1) to (a1-1-33) can be mentioned.

[0055] [Chemical formula 3]

[0056]

[0057] In the above formulas (a1-1-1) to (a1-1-33), R 24b represents a hydrogen atom or a methyl group.

[0058] As a preferable specific example of the structural unit represented by the above formula (a1-2), the structural units represented by the following formulas (a1-2-1) to (a1-2-26) can be mentioned.

[0059] [Chemical formula 4]

[0060]

[0061] In the above formulas (a1-2-1) to (a1-2-26), R 24b represents a hydrogen atom or a methyl group.

[0062] As a preferable specific example of the structural unit represented by the above formula (a1-3), the structural units represented by the following formulas (a1-3-1) to (a1-3-15) can be mentioned.

[0063] [Chemical formula 5]

[0064]

[0065] In the above formulas (a1-3-1) to (a1-3-15), R 24b represents a hydrogen atom or a methyl group.

[0066] Among the structural units represented by the above formulas (a1-1) to (a1-3), the structural unit represented by the formula (a1-1) is preferable. Further, among the structural units represented by the formula (a1-1), the structural unit in which R 16b and R 17b together with the carbon atom to which both are bonded form an aliphatic cyclic group having 5 to 20 carbon atoms is preferable, and R 15b is preferably a linear or branched alkyl group having 1 to 6 carbon atoms.

[0067] As the content ratio of the structural unit (a1) in the resin (A) (the total content ratio in the case of containing a plurality of them), it 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.

[0068] [Structural unit (a2)]

[0069] The structural unit (a2) contains a residue-inhibiting group. The so-called residue-inhibiting group refers to a group that inhibits the generation of residues in the developing process. As the residue-inhibiting group, for example, a cyclic group containing a lactone or a cyclic group containing -SO 2 - can be cited. Among them, a cyclic group containing a lactone is preferred.

[0070] (Cyclic group containing -SO 2 -)

[0071] Here, the so-called "cyclic group containing -SO 2 -" means a cyclic group containing a ring with -SO 2 - in its ring skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO 2 - forms a part of the ring skeleton of the cyclic group. The ring containing -SO 2 - is counted as the first ring. In the case of only this ring, it is called a monocyclic group, and in the case of having other ring structures, it is called a polycyclic group regardless of its structure. The cyclic group containing -SO 2 - can be monocyclic or polycyclic.

[0072] The cyclic group containing -SO 2 - is particularly preferably a cyclic group containing -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 a part of the ring skeleton.

[0073] As the number of carbon atoms of the cyclic group containing -SO 2 -, it is preferably 3 or more and 30 or less, more preferably 4 or more and 20 or less, further preferably 4 or more and 15 or less, and particularly preferably 4 or more and 12 or less. This number of carbon atoms is the number of carbon atoms constituting the ring skeleton and does not include the carbon atoms in the substituents.

[0074] The cyclic group containing -SO 2 - can be an aliphatic cyclic group containing -SO 2 - or an aromatic cyclic group containing -SO 2 -. An aliphatic cyclic group containing -SO 2 - is preferred.

[0075] As the aliphatic cyclic group containing -SO 2 -, examples can be cited from those in which a part of the carbon atoms constituting its ring skeleton is replaced by -SO 2-or -O-SO 2 - a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring. More specifically, examples include a group obtained by replacing -CH 2 - with -SO 2 - a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring, a group obtained by replacing -CH 2 -CH 2 - with -O-SO 2 - a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring, etc.

[0076] As the number of carbon atoms of the alicyclic hydrocarbon ring, it is preferably 3 or more and 20 or less, more preferably 3 or more and 12 or less. The alicyclic hydrocarbon ring can be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing 2 hydrogen atoms from a monocycloalkane having 3 or more and 6 or less carbon atoms is preferred. Examples of the monocycloalkane include cyclopentane, cyclohexane, etc. As the polycyclic alicyclic hydrocarbon ring, a group obtained by removing 2 hydrogen atoms from a polycycloalkane having 7 or more and 12 or less carbon atoms is preferred. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0077] The cyclic group containing -SO 2 - may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, an oxygen atom (=O), -COOR”, -OC(=O)R”, a hydroxyalkyl group, a cyano group, etc.

[0078] Regarding the alkyl group as the substituent, an alkyl group having 1 or more and 6 or less carbon atoms is preferred. The alkyl group is preferably linear or branched. Specifically, examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, etc. Among them, methyl or ethyl is preferred, and methyl is particularly preferred.

[0079] Regarding the alkoxy group as the substituent, an alkoxy group having 1 or more and 6 or less carbon atoms is preferred. The alkoxy group is preferably linear or branched. Specifically, examples include the groups obtained by bonding the alkyl groups listed as the substituents above to an oxygen atom (-O-).

[0080] Regarding the halogen atom as the substituent, examples include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred.

[0081] As the haloalkyl group as the substituent, examples include the groups obtained by replacing a part or all of the hydrogen atoms of the alkyl group above with the halogen atoms above.

[0082] Regarding the haloalkyl group as the substituent, examples thereof include groups obtained by substituting part or all of the hydrogen atoms of the alkyl groups exemplified as the alkyl groups as the substituents with the aforementioned halogen atoms. As the haloalkyl group, a fluoroalkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0083] In the aforementioned -COOR” and -OC(=O)R”, R” is each a hydrogen atom or a linear, branched or cyclic alkyl group having 1 or more and 15 or less carbon atoms.

[0084] When R” is a linear or branched alkyl group, the number of carbon atoms of the linear alkyl group is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, and particularly preferably 1 or 2.

[0085] 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 thereof include groups obtained by removing one or more hydrogen atoms from monocyclic alkanes, bicyclic alkanes, tricyclic alkanes, tetracyclic alkanes and other polycyclic alkanes which may or may not be substituted with fluorine atoms or fluoroalkyl groups. More specifically, examples thereof include groups obtained by removing one or more hydrogen atoms from monocyclic alkanes such as cyclopentane and cyclohexane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane.

[0086] Regarding the hydroxyalkyl group as the substituent, a hydroxyalkyl group having 1 or more and 6 or less carbon atoms is preferred. Specifically, examples thereof include groups obtained by substituting at least one hydrogen atom of the alkyl groups exemplified as the alkyl groups as the substituents with a hydroxy group.

[0087] As the cyclic group containing -SO 2 -, more specifically, examples thereof include groups represented by the following formulas (a2-11) to (a2-14).

[0088] [Chemical formula 6]

[0089]

[0090] (In the formula, A’ is an alkylene group having 1 or more and 5 or less carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, z is an integer of 0 or more and 2 or less, R 10b is an alkyl group, an alkoxy group, a haloalkyl group, a hydroxy group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group, and R” is a hydrogen atom or an alkyl group.)

[0091] 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 preferred, and examples thereof include a methylene group, an ethylene group, a n-propylene group, and an isopropyl group.

[0092] When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is interposed at the terminal or between 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 - etc. As A', an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is most preferred.

[0093] z can be any one of 0, 1, and 2, and 0 is most preferred. When z is 2, the plurality of R 10b can be the same or different from each other.

[0094] As the alkyl group, alkoxy group, haloalkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in R 10b , groups similar to those described above for the substituents that the cyclic group containing -SO 2 - can have can be cited respectively.

[0095] Specific cyclic groups represented by the above formulas (a2-11) to (a2-14) are exemplified below. It should be noted that "Ac" in the formula represents an acetyl group.

[0096] [Chemical formula 7]

[0097]

[0098] [Chemical formula 8]

[0099]

[0100] (Cyclic group containing lactone)

[0101] The so-called "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) having -O-C(=O)- in its ring skeleton. The lactone ring is counted as the first ring. In the case of only the lactone ring, it is called a monocyclic group, and in the case of having other ring structures, it is called a polycyclic group regardless of its structure. The lactone-containing cyclic group can be a monocyclic group or a polycyclic group.

[0102] The lactone cyclic group in the structural unit (a2) is not particularly limited, and any group can be used. Specifically, as the monocyclic group containing a lactone, groups obtained by removing one hydrogen atom from a 4- to 6-membered lactone, such as a group obtained by removing one hydrogen atom from β-propiolactone, a group obtained by removing one hydrogen atom from γ-butyrolactone, a group obtained by removing one hydrogen atom from δ-valerolactone, etc., can be cited. In addition, as the polycyclic group containing a lactone, groups obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring can be cited.

[0103] As the structural unit (a2), as long as it is a structural unit having a cyclic group containing -SO 2 - or a lactone-containing cyclic group, the structure of other parts is not particularly limited. It is preferably at least one structural unit selected from the group consisting of a structural unit (a2-S) derived from an acrylate in which the hydrogen atom bonded to the α-position carbon atom can be substituted by a substituent and containing a cyclic group containing -SO 2 -, and a structural unit (a2-L) derived from an acrylate in which the hydrogen atom bonded to the α-position carbon atom can be substituted by a substituent and containing a lactone-containing cyclic group, and more preferably the structural unit (a2-L).

[0104] [Structural unit (a2-S)]

[0105] As an example of the structural unit (a2-S), more specifically, the structural unit represented by the following formula (a2-S1) can be cited.

[0106] [Chemical formula 9]

[0107]

[0108] (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 11b is a cyclic group containing -SO 2 (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 12b is a single bond or a divalent linking group.)

[0109] In formula (a2-S1), R is the same as described above.

[0110] R11b Similar to the cyclic groups containing -SO 2 - listed in the previous text.

[0111] R 12b can be either a single bond or any of the divalent linking groups. Considering the excellent effects of the present invention, it is preferably a divalent linking group.

[0112] As the divalent linking group in R 12b there is no particular limitation, and preferred groups include divalent hydrocarbon groups that may have substituents, divalent linking groups containing heteroatoms, etc.

[0113] · Divalent hydrocarbon groups that may have substituents

[0114] The hydrocarbon group as the divalent linking group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. This aliphatic hydrocarbon group can be saturated or unsaturated. Usually, a saturated hydrocarbon group is preferred. More specifically, as this aliphatic hydrocarbon group, linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in the structure, etc. can be cited.

[0115] The number of carbon atoms of the aforementioned 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.

[0116] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, methylene [-CH 2 -], ethylene [-(CH 2 ) 2 -], trimethylene [-(CH 2 ) 3 -], tetramethylene [-(CH 2 ) 4 -], pentamethylene [-(CH 2 ) 5 -], etc. can be cited.

[0117] As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. 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 alkylene groups such as -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 alkylene groups such as -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 - and other alkyl trimethylene groups such as -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 - and other alkyl tetramethylene groups and other alkylene groups. As the alkyl group in the alkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0118] The above-mentioned linear or branched aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that substitutes a hydrogen atom. Examples of the substituent include a fluorine atom, a fluoroalkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxo group (=O), and the like.

[0119] Examples of the above-mentioned aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing 2 hydrogen atoms from an aliphatic hydrocarbon ring) that may contain a substituent containing a heteroatom in the ring structure, a group obtained by bonding the cyclic aliphatic hydrocarbon group 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, and the like. Examples of the above-mentioned linear or branched aliphatic hydrocarbon group include the same groups as described above.

[0120] The number of carbon atoms of the cyclic aliphatic hydrocarbon group is preferably 3 or more and 20 or less, more preferably 3 or more and 12 or less.

[0121] The cyclic aliphatic hydrocarbon group can be polycyclic or monocyclic. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing 2 hydrogen atoms from a monocyclic alkane is preferred. The number of carbon atoms of the monocyclic alkane is preferably 3 or more and 6 or less. Specifically, cyclopentane, cyclohexane, etc. can be cited. As the polycyclic aliphatic hydrocarbon group, a group obtained by removing 2 hydrogen atoms from a polycyclic alkane is preferred. The number of carbon atoms of the polycyclic alkane is preferably 7 or more and 12 or less. Specifically, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. can be cited.

[0122] The cyclic aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that substitutes a hydrogen atom. As the substituent, an alkyl group, an alkoxy group, a halogen atom, a haloalkyl group, a hydroxyl group, an oxo group (=O), etc. can be cited.

[0123] Regarding the alkyl group as the above-mentioned substituent, an alkyl group having 1 or more and 5 or less carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, a n-butyl group, and a tert-butyl group are more preferred.

[0124] Regarding the alkoxy group as the above-mentioned substituent, an alkoxy group having 1 or more and 5 or less carbon atoms is preferred, and a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are particularly preferred.

[0125] Regarding the halogen atom as the above-mentioned substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. can be cited, and a fluorine atom is preferred.

[0126] Regarding the haloalkyl group as the above-mentioned substituent, a group obtained by substituting a part or all of the hydrogen atoms of the aforementioned alkyl group with the above-mentioned halogen atom can be cited.

[0127] Regarding the cyclic aliphatic hydrocarbon group, a part of the carbon atoms constituting its ring structure may be substituted with -O- or -S-. As the substituent containing the heteroatom, -O-, -C(=O)-O-, -S-, -S(=O) 2 -, -S(=O) 2 -O-.

[0128] The aromatic hydrocarbon group as a divalent hydrocarbon group is a divalent hydrocarbon group having at least 1 aromatic ring and may have a substituent. The aromatic ring only needs to be a cyclic conjugated system having 4n + 2 π electrons and is not particularly limited, and can 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, further 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.

[0129] As the aromatic ring, specifically, aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene can be mentioned; aromatic heterocycles obtained by substituting a part of the carbon atoms constituting the aforementioned aromatic hydrocarbon ring with heteroatoms; and the like. As the heteroatoms in the aromatic heterocycle, oxygen atom, sulfur atom, nitrogen atom, etc. can be mentioned. As the aromatic heterocycle, specifically, pyridine ring, thiophene ring, etc. can be mentioned.

[0130] Regarding the aromatic hydrocarbon group as the divalent hydrocarbon group, specifically, groups obtained by removing two hydrogen atoms from the above-mentioned aromatic hydrocarbon ring or aromatic heterocycle (arylene or heteroarylene); groups obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); groups obtained by substituting one hydrogen atom of the group obtained by removing one hydrogen atom from the above-mentioned aromatic hydrocarbon ring or aromatic heterocycle (aryl or heteroaryl) with an alkylene group (for example, groups obtained by further removing one hydrogen atom from the aryl in arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.); and the like.

[0131] The number of carbon atoms of the alkylene group bonded to the above-mentioned aryl or heteroaryl is preferably 1 or more and 4 or less, more preferably 1 or more and 2 or less, and particularly preferably 1.

[0132] Regarding the above-mentioned aromatic hydrocarbon group, the hydrogen atoms possessed by the aromatic hydrocarbon group can be substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group can be substituted with substituents. As the substituents, for example, alkyl group, alkoxy group, halogen atom, haloalkyl group, hydroxyl group, oxo group (=O), etc. can be mentioned.

[0133] Regarding the alkyl group as the above-mentioned substituent, an alkyl group having 1 or more and 5 or less carbon atoms is preferred, and methyl, ethyl, n-propyl, n-butyl, and tert-butyl are more preferred.

[0134] Regarding the alkoxy group as the above-mentioned substituent, an alkoxy group having 1 or more and 5 or less carbon atoms is preferred, and methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, and tert-butoxy are preferred, and methoxy and ethoxy are more preferred.

[0135] Regarding the halogen atom as the above-mentioned substituent, fluorine atom, chlorine atom, bromine atom, iodine atom, etc. can be mentioned, and fluorine atom is preferred.

[0136] Regarding the haloalkyl group as the above-mentioned substituent, groups obtained by substituting a part or all of the hydrogen atoms of the aforementioned alkyl group with the aforementioned halogen atoms can be mentioned.

[0137] · Divalent linking group containing a heteroatom

[0138] The heteroatom in the divalent linking group containing a heteroatom refers to an atom other than a carbon atom and a hydrogen atom. For example, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc. can be cited.

[0139] 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. As the divalent hydrocarbon group, the same hydrocarbon groups as those of the divalent hydrocarbon group having a substituent described above can be cited, and a linear or branched aliphatic hydrocarbon group is preferred.

[0140] Among the above, the -NH- in -C(=O)-NH-, -NH-, and the H in -NH-C(=NH)- can each be substituted with a substituent such as an alkyl group or an acyl group. The number of carbon atoms of this 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.

[0141] As the divalent linking group in R 12b is particularly preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group or a divalent linking group containing a heteroatom.

[0142] When the divalent linking group in R 12b is a linear or branched alkylene group, the number of carbon atoms of this 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, the same alkylene groups as the linear alkylene group and the branched alkylene group cited as the linear or branched aliphatic hydrocarbon group in the description of the "divalent hydrocarbon group having a substituent" as the foregoing divalent linking group can be cited.

[0143] When the divalent linking group in R 12b is a cyclic aliphatic hydrocarbon group, as this cyclic aliphatic hydrocarbon group, the same groups as the cyclic aliphatic hydrocarbon groups cited as the "aliphatic hydrocarbon group containing a ring in the structure" in the description of the "divalent hydrocarbon group having a substituent" as the foregoing divalent linking group can be cited.

[0144] As this 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 preferred.

[0145] When the divalent linking group in R 12bWhen the divalent linking group in [compound] is a divalent linking group containing a heteroatom, examples of preferred groups as the linking group include -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH- (where H may be substituted by substituents such as alkyl, acyl, etc.), -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 - represents a group [wherein, Y 1 and Y 2 each independently is 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.

[0146] When the divalent linking group in R 12b is -NH-, the hydrogen atom in -NH- may be substituted by substituents such as alkyl, acyl, etc. The carbon number of the substituent (alkyl, acyl, 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.

[0147] In the general formula -Y 1 -O-Y 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 -O-C(=O)-Y 2 -, Y 1 and Y 2 each independently is a divalent hydrocarbon group which may have a substituent. As the divalent hydrocarbon group, examples include the same groups as the "divalent hydrocarbon group which may have a substituent" listed in the description of the aforementioned divalent linking group.

[0148] As Y 1 , it is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group and an ethylene group.

[0149] As Y 2 , it is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group and an alkylmethylene group. The alkyl 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.

[0150] The group represented by -[Y 1 -C(=O)-O] m’ -Y 2 - In the group represented by, 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, as the group represented by -[Y 1 -C(=O)-O] m’ -Y 2 -, the group represented by is particularly preferably the group represented by -Y 1 -C(=O)-O-Y 2 -. Among them, the group represented by the formula -(CH 2 ) a’ -C(=O)-O-(CH 2 ) b’ - is preferred. In this 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, further 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, further preferably 1 or 2, and most preferably 1.

[0151] Regarding the divalent linking group in R 12b , as the divalent linking group containing a heteroatom, an organic group formed by 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, such as a group containing an ether bond or an ester bond, is preferred, and more preferably the aforementioned group represented by -Y 1 -O-Y 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 -O-C(=O)-Y 2 - is preferred, and particularly preferably the aforementioned group represented by -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 -O-C(=O)-Y 2 -.

[0152] As the divalent linking group in R 12b , an alkylene group or a divalent linking group containing an ester bond (-C(=O)-O-) is preferred.

[0153] This alkylene group is preferably a linear or branched alkylene group. As a preferred example of this linear aliphatic hydrocarbon group, methylene [-CH 2-], ethylene [-(CH 2 ) 2 -], trimethylene [-(CH 2 ) 3 -], tetramethylene [-(CH 2 ) 4 -] and pentamethylene [-(CH 2 ) 5 -], etc. Preferred examples of such branched alkylene groups 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. alkylene methines; -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. alkylene ethylenes; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc. alkylene trimethylenes; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 -, etc. alkylene tetramethylenes and other alkylene groups, etc.

[0154] As a divalent linking group containing an ester bond, the following formula is particularly preferred: -R 13b -C(=O)-O-[wherein R 13b is a divalent linking group. ] represents a group. That is, the structural unit (a2-S) is preferably a structural unit represented by the following formula (a2-S1-1).

[0155] [Chemical formula 10]

[0156]

[0157] (In the formula, R and R 11b are the same as described above, and R 13b is a divalent linking group. )

[0158] As R 13b , there is no particular limitation. For example, groups similar to the divalent linking groups in the aforementioned R 12b can be cited.

[0159] As the divalent linking group of R 13b , 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 more preferred.

[0160] As the linear alkylene group, methylene or ethylene is preferred, and methylene is particularly preferred. As the branched alkylene group, alkylmethylene or alkylethylene is preferred, and -CH(CH 3 )-, -C(CH 3 ) 2 - or -C(CH 3 ) 2 CH 2 - are particularly preferred.

[0161] 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 - are more preferred. Y 1 and Y 2 are 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 -represents a group. c is an integer of 1 or more and 5 or less, preferably 1 or 2. d is an integer of 1 or more and 5 or less, preferably 1 or 2.

[0162] As the structural unit (a2-S), the structural unit represented by the following formula (a2-S1-11) or (a2-S1-12) is particularly preferred, and the structural unit represented by the formula (a2-S1-12) is more preferred.

[0163] [Chemical formula 11]

[0164]

[0165] (In the formula, R, A', R 10b , z and R 13b are the same as those described above respectively.)

[0166] In the formula (a2-S1-11), A' is preferably a methylene group, an oxygen atom (-O-) or a sulfur atom (-S-).

[0167] As R 13b , it 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 groups as those of the aforementioned linear or branched alkylene group and the divalent linking group containing an oxygen atom can be cited respectively.

[0168] As the structural unit represented by the formula (a2-S1-12), the structural unit represented by the following formula (a2-S1-12a) or (a2-S1-12b) is particularly preferred.

[0169] [Chemical formula 12]

[0170]

[0171] (In the formula, R and A' are the same as those described above respectively, and c to e are each independently an integer of 1 or more and 3 or less.)

[0172] [Structural unit (a2-L)]

[0173] As an example of the structural unit (a2-L), for example, a structural unit obtained by substituting R 11b in the aforementioned formula (a2-S1) with a cyclic group containing a lactone can be cited. More specifically, the structural units represented by the following formulas (a2-L1) to (a2-L5) can be cited.

[0174] [Chemical formula 13]

[0175]

[0176] (In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a haloalkyl group having 1 to 5 carbon atoms; each R' is independently a hydrogen atom, an alkyl group, an alkoxy group, a haloalkyl 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.)

[0177] R in formulas (a2-L1) to (a2-L5) is the same as described above.

[0178] As the alkyl group, alkoxy group, haloalkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in R', examples thereof include the same groups as those described above for the alkyl group, alkoxy group, haloalkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group which can be substituents that a cyclic group containing -SO 2 - may have.

[0179] When considering easy availability in industry, etc., R' is preferably a hydrogen atom.

[0180] The alkyl group in R" may be linear, branched, or cyclic.

[0181] When R" is a linear or branched alkyl group, the number of carbon atoms is preferably 1 or more and 10 or less, and more preferably 1 or more and 5 or less.

[0182] When R" is a cyclic alkyl group, the number of carbon atoms is preferably 3 or more and 15 or less, more preferably 4 or more and 12 or less, and most preferably 5 or more and 10 or less. Specifically, examples thereof include groups obtained by removing one or more hydrogen atoms from monocyclic alkanes, bicyclic alkanes, tricyclic alkanes, tetracyclic alkanes, etc., which may or may not be substituted with a fluorine atom or a fluoroalkyl group. Specifically, examples include groups obtained by removing one or more hydrogen atoms from monocyclic alkanes such as cyclopentane and cyclohexane, and polycyclic alkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0183] As "A", groups similar to A' in the aforementioned formula (3-1) can be cited. 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, methylene or dimethylmethylene is more preferred, and methylene is most preferred.

[0184] R 12b is the same as R in the aforementioned formula (a2-S1). 12b Same.

[0185] In formula (a2-L1), s" is preferably 1 or 2.

[0186] Specific examples of the structural units represented by the aforementioned formulas (a2-L1) to (a2-L3) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0187] [Chemical formula 14]

[0188]

[0189] [Chemical formula 15]

[0190]

[0191] [Chemical formula 16]

[0192]

[0193] 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 preferred, at least one selected from the group consisting of the structural units represented by formulas (a2-L1) to (a2-L3) is more preferred, at least one selected from the group consisting of the structural units represented by the aforementioned formulas (a2-L1) or (a2-L3) is particularly preferred, and the structural unit represented by formula (a2-L1) is most preferred.

[0194] 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 preferred.

[0195] In addition, as the structural unit (a2-L), the structural units represented by the following formulas (a2-L6) to (a2-L7) are also preferred.

[0196] [Chemical formula 17]

[0197]

[0198] In formulas (a2-L6) and (a2-L7), R and R 12b Are the same as described above.

[0199] The content ratio of the structural unit (a2) in the resin (A) (the total content ratio in the case of containing a plurality of them) 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.

[0200] The total content ratio of the structural unit (a1) and the structural unit (a2) in the resin (A) (the total content ratio in the case of containing a plurality of them) is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. The total content ratio may also be 100% by mass.

[0201] In addition, in the resin (A), other polymerizable compounds may be included as structural units for the purpose of appropriately controlling physical and chemical properties. Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds.

[0202] 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 carboxyl group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2

[0203] -Methacryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid, etc.; (meth)acrylic acid alkyl esters such as (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, and (meth)acrylic acid cyclohexyl ester; (meth)acrylic acid hydroxyalkyl esters such as (meth)acrylic acid 2-hydroxyethyl ester and (meth)acrylic acid 2-hydroxypropyl ester; (meth)acrylic acid aryl esters such as (meth)acrylic acid phenyl ester and (meth)acrylic acid benzyl ester; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; aromatic compounds containing a vinyl group such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene; aliphatic compounds containing a vinyl group such as vinyl acetate; conjugated dienes such as butadiene and isoprene; polymerizable compounds containing a nitrile group such as acrylonitrile and methacrylonitrile; polymerizable compounds containing chlorine such as vinyl chloride and vinylidene chloride; polymerizable compounds containing an amide bond such as acrylamide and methacrylamide; and the like.

[0204] The weight-average molecular weight of the resin (A) described above in terms of polystyrene is preferably 1,000 or more and 500,000 or less, more preferably 2,000 or more and 100,000 or less, and still more preferably 3,000 or more and 50,000 or less. By setting the weight-average molecular weight in this way, it is easy to maintain sufficient strength of the photosensitive resin composition layer without reducing the peelability from the substrate.

[0205] 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 still more preferably 1.3 or more and 1.8 or less. Here, the dispersity is a value obtained by dividing the weight-average molecular weight by the number-average molecular weight.

[0206] As the Onishi parameter of the resin (A), it is preferably 3 or more and 5 or less, more preferably 3.5 or more and 4.5 or less. In this specification, the Onishi parameter is a 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 the following method: counting the number of each atom from the structural formula of each repeating unit contained in the resin (A), obtaining the Onishi parameter of each repeating unit, and adding together the values obtained by multiplying this value by the content ratio (molar ratio) of each repeating unit.

[0207] As the ring parameter of the resin (A), it is preferably less than 1, more preferably 0.5 or less. In addition, 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 is a 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 the following method: obtaining the ring parameter of each repeating unit from the structural formula of each repeating unit contained in the resin (A), and adding together the values obtained by multiplying this value by the content ratio (molar ratio) of each repeating unit. The ring parameter becomes an index of dry etching resistance.

[0208] With respect to the total solid content of the photosensitive resin composition, the content of the resin (A) is preferably set to 30% by mass or more and 99% by mass or less, more preferably set to 50% by mass or more and 99% by mass or less, still more preferably set to 70% by mass or more and 99% by mass or less, and particularly preferably set to 90% by mass or more and 99% by mass or less.

[0209] <Photoacid generator (B)>

[0210] The photoacid generator (B) is a compound that generates an acid upon irradiation with actinic rays or radiation, and any compound that directly or indirectly generates an acid using light is acceptable without particular limitation. As the photoacid generator (B), the photoacid generators of the first to fifth modes described below are preferred, and from the aspect of being easily able to form a fine microlens pattern both in the case of using a KrF excimer laser and in the case of using an ArF excimer laser, the photoacid generator of the first mode is more preferred. Hereinafter, the preferred photoacid generators in the photoacid generator (B) used in the photosensitive resin composition will be described as the first to fifth modes.

[0211] As the first mode in the photoacid generator (B), a compound represented by the following formula (b1) can be cited.

[0212] [Chemical formula 18]

[0213]

[0214] In the above formula (b1), X 1a represents a sulfur atom or an iodine atom with a valence of 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 1a may be substituted with at least one selected from the group consisting of an alkyl group, a hydroxyl 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 heterocycle, 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. The number of R 1a is g + h(g - 1) + 1, and the R 1a may be the same as or different from each other. In addition, 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.

[0215] X 2a is a structure represented by the following formula (b2).

[0216] [Chemical Formula 19]

[0217]

[0218] 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. X 4a may be 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 hydroxyl group, a cyano group, a nitro group, and a halogen. X 5a represents -O-, -S-, -SO-, -SO 2 -, -NH-, -NR 2a -, -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 has the same definition as described above.

[0219] X 3a- is a counter ion of an onium, and examples thereof include a fluoroalkyl fluorophosphate anion represented by the following formula (b17) or a borate anion represented by the following formula (b18).

[0220] [Chemical Formula 20]

[0221] |(R 3a ) j PF 6-j | - (b17)

[0222] 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 represents the number thereof, and is an integer of 1 to 5. j R 3a may be the same or different from each other.

[0223] [Chemical Formula 21]

[0224]

[0225] In the above formula (b18), R 4a to 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.

[0226] As X 3a- , anions represented by the following formulas (bI) to (bIII) can also be cited.

[0227] [Chemical formula 22]

[0228]

[0229] (In formulas (bI) to (bIII), v0 is an integer of 0 or more and 3 or less, q1 is an integer of 1 or more and 5 or less, q3 is an integer of 1 or more and 12 or less, r1 and r2 are each independently an integer of 0 or more and 3 or less, i is an integer of 1 or more and 2 or less, t3 is an integer of 1 or more and 3 or less, and R b33 is a substituent.)

[0230] As the substituent R b33 , alkyl groups, substituents containing heteroatoms, etc. can be cited.

[0231] Regarding the alkyl group as the substituent, an alkyl group having 1 or more and 5 or less carbon atoms is preferable, and methyl, ethyl, propyl, n-butyl, and tert-butyl are more preferable.

[0232] Regarding the substituent containing a heteroatom as the substituent, 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 haloalkyl group, a haloalkoxy group, an amino group, an amide group, a nitro group, an oxygen atom (=O), a sulfur atom, a sulfonyl group (SO 2 ) etc. can be cited.

[0233] Regarding the halogen atom as the substituent containing a heteroatom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. can be cited, and a fluorine atom is preferable.

[0234] Regarding the alkyl group in the alkoxy group as a substituent containing a heteroatom, it can be linear, branched, cyclic, or any 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, further preferably 1 or more and 15 or less, and particularly preferably 1 or more and 10 or less. When the alkyl group is cyclic (in the case of 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, further 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 can be monocyclic or polycyclic. Specifically, groups obtained by removing one or more hydrogen atoms from monocyclic alkanes, groups obtained by removing one or more hydrogen atoms from polycyclic alkanes such as bicyclic alkanes, tricyclic alkanes, and tetracyclic alkanes, etc. can be exemplified. Specific examples of monocyclic alkanes include cyclopentane, cyclohexane, etc. In addition, specific examples of polycyclic alkanes include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. Regarding these cycloalkyl groups, some or all of the hydrogen atoms bonded to the ring can be substituted with substituents such as fluorine atoms and fluoroalkyl groups, or can be unsubstituted with substituents such as fluorine atoms and fluoroalkyl groups.

[0235] -C(=O)-R as a substituent containing a heteroatom b25 , -COOR b26 Among them, as R b25 and R b26 The alkyl groups in can be exemplified by the same alkyl groups as those listed as the alkyl groups in the aforementioned alkoxy group.

[0236] Regarding the alkyl group in the haloalkyl group as a substituent containing a heteroatom, the same alkyl groups as those listed as the alkyl groups in the alkoxy group can be exemplified. As the haloalkyl group, a fluoroalkyl group is particularly preferred.

[0237] Regarding the haloalkoxy group as a substituent containing a heteroatom, a group obtained by substituting some or all of the hydrogen atoms of the alkoxy group with the aforementioned halogen atoms can be exemplified. As the haloalkoxy group, a fluoroalkoxy group is preferred.

[0238] When the symbols (r1, r2) attached to R b33 are integers of 2 or more, the multiple Rs in the same compound b33 can be the same or different from each other.

[0239] R b34 The alkyl group in can be linear, branched, or cyclic. The number of carbon atoms of the alkyl group is preferably 1 or more and 4 or less.

[0240] As Rb34 The haloalkyl group in [compound] can be a group obtained by substituting some or all of the hydrogen atoms of the aforementioned linear, branched or cyclic alkyl group with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.

[0241] Each of R1 and R2 is 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.

[0242] 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, diphenylbenzoylmethylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 2-naphthylmethyl(1-ethoxycarbonyl)ethylsulfonium, 4-hydroxyphenylmethylbenzoylmethylsulfonium, phenyl[4-(4-biphenylthio)phenyl]4-biphenylsulfonium, phenyl[4-(4-biphenylthio)phenyl]3-biphenylsulfonium, [4-(4-acetylphenylthio)phenyl]diphenylsulfonium, octadecylmethylbenzoylmethylsulfonium, diphenyliodonium, di-p-tolyliodonium, bis(4-dodecylphenyl)iodonium, bis(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyliodonium, bis(4-decyloxy)phenyliodonium, 4-(2-hydroxytetradecyloxy)phenylphenyliodonium, 4

[0243] -isopropylphenyl(p-tolyl)iodonium or 4-isobutylphenyl(p-tolyl)iodonium, etc.

[0244] Among the onium ions in the compound represented by the above formula (b1), as the preferred onium ion, considering the aspect that it is easy to form a fine microlens pattern both in the case of using a KrF excimer laser and in the case of using an ArF excimer laser, the sulfonium ion represented by the following formula (b19) can be mentioned.

[0245] [Chemical formula 23]

[0246]

[0247] In the above formula (b19), R 8a each independently represents a group selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxy group, an alkoxy group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyl group, a halogen atom, an aryl group which may have a substituent, and an arylcarbonyl group. As R 8a , a hydrogen atom or an alkyl group is preferred. As the alkyl group of R 8a , the number of carbon atoms is preferably 1 or more and 5 or less.

[0248] In the fluoroalkyl 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, and octyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, and tert-butyl; and cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. The proportion of hydrogen atoms of the alkyl group substituted with fluorine atoms is usually 80% or more, preferably 90% or more, and more preferably 100%. When the substitution rate of fluorine atoms is less than 80%, the acid strength of the fluoroalkyl fluorophosphate salt represented by the above formula (b1) decreases.

[0249] Particularly preferred R 3a is a linear or branched perfluoroalkyl group having 1 or more and 4 or less carbon atoms and a fluorine atom substitution rate of 100%. Specific examples include CF 3 , 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 of 1 or more and 5 or less, preferably 2 or more and 4 or less, and particularly preferably 2 or 3.

[0250] Specific examples of the preferred fluoroalkyl fluorophosphate anion include [(CF 3 CF2 ) 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 - , among them, particularly preferred is [(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 ] - .

[0251] Preferred specific examples of the borate anion represented by the 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 ] - ) etc. Among them, tetrakis(pentafluorophenyl)borate ([B(C 6 F 5 ) 4 ] - ).

[0252] As the second mode in the photoacid generator (B), examples thereof include 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(2-furyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methyl-2-furyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-ethyl-2-furyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-propyl-2-furyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dimethoxyphenyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-diethoxyphenyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dipropoxyphenyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-ethoxyphenyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-propoxyphenyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,4-methylenedioxyphenyl)vinyl]s-triazine, 2,4-bis(trichloromethyl)-6-(3,4-methylenedioxyphenyl)s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)phenyls-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)phenyls-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)styrylphenyls-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)styrylphenyls-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)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(5-methyl-2-furyl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,5-dimethoxyphenyl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,4-dimethoxyphenyl)vinyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4-methylenedioxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, tris(1,3-dibromopropyl)-1,3,5-triazine, tris(2,3-dibromopropyl)-1,3,5-triazine and other halogen-containing triazine compounds, and halogen-containing triazine compounds represented by the following formula (b3) such as tris(2,3-dibromopropyl) isocyanurate.

[0253] [Chemical formula 24]

[0254]

[0255] In the above formula (b3), R 9a , R 10a , R 11a each independently represents a haloalkyl group.

[0256] In addition, as the third mode in the photoacid generator (B), examples thereof include α-(p-toluenesulfonyloxyimino)-phenylacetonitrile, α-(benzenesulfonyloxyimino)-2,4-dichlorophenylacetonitrile, α-(benzenesulfonyloxyimino)-2,6-dichlorophenylacetonitrile, α-(2-chlorobenzenesulfonyloxyimino)-4-methoxyphenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, and a compound represented by the following formula (b4) containing an oxime sulfonate group.

[0257] [Chemical formula 25]

[0258]

[0259] In the above formula (b4), R 12a represents a monovalent, divalent or trivalent organic group, R 13a represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic group, and n represents the number of repeating units of the structure in parentheses.

[0260] In the above formula (b4), as the aromatic group, for example, aryl groups such as phenyl and naphthyl, and heteroaryl groups such as furyl and thienyl can be mentioned. They 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. In addition, R 13a is particularly preferably an alkyl group having 1 to 6 carbon atoms, and examples thereof include methyl, ethyl, propyl and butyl. Particularly preferably, R 12a is an aromatic group and R 13a is a compound in which the alkyl group has 1 to 4 carbon atoms.

[0261] As the acid generator represented by the above formula (b4), when n = 1, examples thereof include compounds in which R 12a is any one of phenyl, methylphenyl and methoxyphenyl, and R 13a is methyl. 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. When n = 2, as the acid generator represented by the above formula (b4), specifically, an acid generator represented by the following formula can be mentioned.

[0262] [Chemical Formula 26]

[0263]

[0264] In addition, as the fourth mode of the photoacid generator (B), an onium salt having a naphthalene ring in the cationic moiety can be cited. The "having a naphthalene ring" means having a structure derived from naphthalene, representing a structure of at least two rings, and maintaining their aromaticity. The naphthalene ring may have substituents such as a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. The structure derived from the naphthalene ring may be a monovalent group (with a free valence of 1) or a divalent group (with a free valence of 2) or more, but a monovalent group is preferred (wherein, in this case, the free valence is counted excluding the part bonded to the above-mentioned substituents). The number of naphthalene rings is preferably 1 to 3.

[0265] As the cationic moiety of such an onium salt having a naphthalene ring in the cationic moiety, a structure represented by the following formula (b5) is preferred.

[0266] [Chemical Formula 27]

[0267]

[0268] 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 their ends may be bonded to form a ring.

[0269] [Chemical Formula 28]

[0270]

[0271] In the above formula (b6), R 17a , R 18a each independently represent 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 19arepresents a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms which may have substituents. l and m each independently represent an integer of 0 or more and 2 or less, and l + m is 3 or less. Among them, R 17a When there are a plurality of them, they may be the same as or different from each other. Further, R 18a When there are a plurality of them, they may be the same as or different from each other.

[0272] From the viewpoint of the stability of the compound, the above-mentioned R 14a 、R 15a 、R 16a The number of the groups represented by the above formula (b6) is preferably 1, and the rest are linear or branched alkylene groups having 1 to 6 carbon atoms, and their ends may be bonded to form a ring. In this case, the above two alkylene groups contain a sulfur atom to form a 3- to 9-membered ring. The number of atoms (including sulfur atoms) constituting the ring is preferably 5 or more and 6 or less.

[0273] In addition, examples of the substituents that the above-mentioned 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.

[0274] In addition, examples of the substituents 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.

[0275] Regarding the structure preferably used as such a cation moiety, structures represented by the following formulas (b7), (b8), etc. can be mentioned, and the structure represented by the following formula (b8) is particularly preferred.

[0276] [Chemical formula 29]

[0277]

[0278] As such a cation moiety, it may be an iodonium salt or a sulfonium salt, but from the viewpoints of acid generation efficiency and the like, a sulfonium salt is desired.

[0279] Therefore, regarding the anion preferably used as the anion moiety of the onium salt having a naphthalene ring in the cation moiety, an anion capable of forming a sulfonium salt is desired.

[0280] As the anion 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.

[0281] The alkyl group in the fluoroalkylsulfonate ion may be linear with 1 to 20 carbon atoms, branched, or cyclic. Considering the large volume of the acid generated and its diffusion distance, it is preferably linear with 1 to 10 carbon atoms. In particular, when it is a branched or cyclic alkyl group, the diffusion distance is short, so it is preferred. In addition, from the aspect of being able to be synthesized inexpensively, methyl, ethyl, propyl, butyl, octyl, etc. can be cited as preferred examples.

[0282] The aryl group in the arylsulfonate ion is an aryl group with 6 to 20 carbon atoms, and phenyl, naphthyl which may or may not be substituted by an alkyl group or a halogen atom can be cited. In particular, from the aspect of being able to be synthesized inexpensively, it is preferably an aryl group with 6 to 10 carbon atoms. Specific examples of the preferred aryl group can include phenyl, toluenesulfonyl, ethylphenyl, naphthyl, methylnaphthyl, etc.

[0283] 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, the product obtained by substituting all hydrogen atoms with fluorine atoms has a stronger acid strength, so it is preferred. Specific examples of such substances include trifluoromethanesulfonate, perfluorobutanesulfonate, perfluorooctanesulfonate, perfluorobenzenesulfonate, etc.

[0284] Among them, as the preferred anion part, the anion part represented by the following formula (b9) can be cited.

[0285] [Chemical formula 30]

[0286] R 20a SO 3 - (b9)

[0287] In the above formula (b9), R 20a is a group represented by the following formulas (b10), (b11) and (b12).

[0288] [Chemical formula 31]

[0289]

[0290] In the above formula (b10), x represents an integer of 1 or more and 4 or less. In addition, in the above formula (b11), R 21a represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group with 1 to 6 carbon atoms or a linear or branched alkoxy group with 1 to 6 carbon atoms, and y represents an integer of 1 or more and 3 or less. Among them, from the viewpoint of safety, trifluoromethanesulfonate and perfluorobutanesulfonate are preferred.

[0291] In addition, as the anionic moiety, a nitrogen-containing anionic moiety represented by the following formulas (b13) and (b14) can also be used.

[0292] [Chemical Formula 32]

[0293]

[0294] 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. In addition, 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.

[0295] X a The smaller the number of carbon atoms of the alkylene group or Y a , Z a of the alkyl group, the better the solubility in the organic solvent, and thus it is preferred.

[0296] In addition, in the alkylene group of X a or Y a , Z a of the alkyl group, the larger the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and thus it is preferred. The ratio of fluorine atoms, i.e., 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 obtained by substituting all hydrogen atoms with fluorine atoms.

[0297] Regarding compounds preferably used as such onium salts having a naphthalene ring in the cationic moiety, compounds represented by the following formulas (b15) and (b16) can be mentioned.

[0298] [Chemical Formula 33]

[0299]

[0300] Further, as the fifth mode of the photoacid generator (B), bis(sulfonyl)diazomethanes 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 toluenesulfonate, dinitrobenzyl toluenesulfonate, nitrobenzyl sulfonate, nitrobenzyl carbonate, dinitrobenzyl carbonate; sulfonates such as pyrogallol trimethanesulfonate, pyrogallol trimethylbenzenesulfonate, benzyl toluenesulfonate, benzyl sulfonate, N-methylsulfonyloxysuccinimide, N-trichloromethylsulfonyloxysuccinimide, N-phenylsulfonyloxymaleimide, N-methylsulfonyloxyphthalimide; trifluoromethanesulfonates 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)phenyl iodonium trifluoromethanesulfonate, bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, (p-tert-butylphenyl)diphenylsulfonium trifluoromethanesulfonate; benzoin toluenesulfonates such as benzoin toluenesulfonate, α-methylbenzoin toluenesulfonate; other diphenyliodonium salts, triphenylsulfonium salts, phenyl diazonium salts, benzyl carbonate, etc.

[0301] As the photoacid generator (B), naphthalenedicarboxylic acid derivatives represented by the following formula (b21) are also preferable.

[0302] [Chemical formula 34]

[0303]

[0304] (In formula (b21), R 22a is a monovalent organic group, and R 23a , R 24a , R 25a and R 26a are each independently a hydrogen atom or a monovalent organic group, and R 23a and R 24a , R 24a and R 25a , or R 25a and R 26a may each bond to each other to form a ring.)

[0305] As R 22aThe organic group is not particularly limited as long as it does not hinder the object of the present invention. The organic group may be a hydrocarbon group or may contain heteroatoms such as O, N, S, P, and halogen atoms. In addition, the structure of the organic group may be linear, branched, cyclic, or a combination of these structures.

[0306] Regarding R 22a Preferred organic groups include aliphatic hydrocarbon groups having 1 to 18 carbon atoms that may be substituted with halogen atoms and / or alkylthio groups, aryl groups having 6 to 20 carbon atoms that may have substituents, aralkyl groups having 7 to 20 carbon atoms that may have substituents, alkylaryl groups having 7 to 20 carbon atoms that may have substituents, camphor-10-yl, and a group represented by the following formula (b21a).

[0307] -R 27a -(O) a -R 28a -(O) b -Y 1 -R 29a ···(b21a)

[0308] (In formula (b21a), Y 1 is a single bond or an alkylene group having 1 to 4 carbon atoms. R 27a and R 28a are each an alkylene group having 2 to 6 carbon atoms that may be substituted with a halogen atom or an arylene group having 6 to 20 carbon atoms that may be substituted with a halogen atom. R 29a is an alkyl group having 1 to 18 carbon atoms that 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 that may be substituted with a halogen atom, or an aralkyl group having 7 to 20 carbon atoms that 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.)

[0309] When the organic group as 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.

[0310] When the organic group as R 22a 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.

[0311] Examples of the alkylthio group having 1 to 18 carbon atoms include methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, sec-butylthio, tert-butylthio, isobutylthio, n-pentylthio, isopentylthio, tert-pentylthio, n-hexylthio, n-heptylthio, isoheptylthio, tert-heptylthio, n-octylthio, isooctylthio, tert-octylthio, 2-ethylhexylthio, n-nonylthio, n-decylthio, n-undecylthio, n-dodecylthio, n-tridecylthio, n-tetradecylthio, n-pentadecylthio, n-hexadecylthio, n-heptadecylthio, and n-octadecylthio.

[0312] When the organic group for R 22a is an aliphatic hydrocarbon group having 1 to 18 carbon atoms that may be substituted with a halogen atom and / or an alkylthio group, the aliphatic hydrocarbon group may contain an unsaturated double bond.

[0313] In addition, the structure of the aliphatic hydrocarbon group is not particularly limited and may be linear, branched, cyclic, or a combination of these structures.

[0314] Regarding preferred examples when the organic group for R 22a is an alkenyl group, examples include allyl and 2-methyl-2-propenyl.

[0315] Regarding preferred examples when the organic group for R 22a is an alkyl group, examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, n-hexyl, hexan-2-yl, hexan-3-yl, n-heptyl, heptan-2-yl, heptan-3-yl, isoheptyl, tert-heptyl, n-octyl, isooctyl, tert-octyl, 2-ethylhexyl, n-nonyl, isononyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, and n-octadecyl.

[0316] When the organic group for R 22a is an alicyclic hydrocarbon group, examples of the alicyclic hydrocarbon that forms 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 preferred.

[0317] Regarding R 22aPreferred examples in the case where the organic group of R is an aliphatic hydrocarbon group substituted by a halogen atom include trifluoromethyl, pentafluoroethyl, 2-chloroethyl, 2-bromoethyl, heptafluoropropyl, 3-bromopropyl, nonafluorobutyl, tridecafluorohexyl, heptadecafluorooctyl, 2,2,2-trifluoroethyl, 1,1-difluoroethyl, 1,1-difluoropropyl, 1,1,2,2-tetrafluoropropyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 2-norbornanyl-1,1-difluoroethyl, 2-norbornanyl tetrafluoroethyl, and 3-adamantyl-1,1,2,2-tetrafluoropropyl.

[0318] Regarding the case where the organic group of R 22a is an aliphatic hydrocarbon group substituted by an alkylthio group, preferred examples include 2-methylthioethyl, 4-methylthion-butyl, and 2-n-butylthioethyl.

[0319] Regarding the case where the organic group of R 22a is an aliphatic hydrocarbon group substituted by a halogen atom and an alkylthio group, a preferred example is 3-methylthio-1,1,2,2-tetrafluoropropyl.

[0320] Regarding the case where the organic group of R 22a is an aryl group, preferred examples include phenyl, naphthyl, and biphenyl.

[0321] Regarding the case where the organic group of R 22a is an aryl group substituted by a halogen atom, preferred examples include pentafluorophenyl, chlorophenyl, dichlorophenyl, and trichlorophenyl.

[0322] Regarding the case where the organic group of R 22a is an aryl group substituted by an alkylthio group, preferred examples include 4-methylthiophenyl, 4-n-butylthiophenyl, 4-n-octylthiophenyl, and 4-n-dodecylthiophenyl.

[0323] Regarding the case where the organic group of R 22a is an aryl group substituted by a halogen atom and an alkylthio group, preferred examples include 1,2,5,6-tetrafluoro-4-methylthiophenyl, 1,2,5,6-tetrafluoro-4-n-butylthiophenyl, and 1,2,5,6-tetrafluoro-4-n-dodecylthiophenyl.

[0324] Regarding the case where the organic group of R 22a is an aralkyl group, preferred examples include benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, and triphenylmethyl.

[0325] Regarding the case where the organic group of R 22aPreferred examples in the case where the organic group of [is] an aralkyl group substituted by a halogen atom include pentafluorophenylmethyl, phenyldifluoromethyl, 2-phenyltetrafluoroethyl, 2-(pentafluorophenyl)ethyl.

[0326] Regarding R 22a Preferred examples in the case where the organic group of [is] an aralkyl group substituted by an alkylthio group include p-methylthiobenzyl.

[0327] Regarding R 22a Preferred examples in the case where the organic group of [is] an aralkyl group substituted by a halogen atom and an alkylthio group include 2-(2,3,5,6-tetrafluoro-4-methylthiophenyl)ethyl.

[0328] Regarding R 22a Preferred examples in the case where the organic group of [is] an alkylaryl group include 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4-n-butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-n-hexylphenyl, 4-cyclohexylphenyl, 4-n-octylphenyl, 4-(2-ethylhexyl)phenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butylphenyl, 2,5-di-tert-butylphenyl, 2,6-di-tert-butylphenyl, 2,4-di-tert-amylphenyl, 2,5-di-tert-amylphenyl, 2,5-di-tert-octylphenyl, 2-cyclohexylphenyl, 3-cyclohexylphenyl, 4-cyclohexylphenyl, 2,4,5-trimethylphenyl, 2,4,6-trimethylphenyl, 2,4,6-triisopropylphenyl.

[0329] The group represented by formula (b21a) is a group containing an ether group.

[0330] In formula (b21a), as the alkylene group having 1 to 4 carbon atoms represented by Y 1 include methylene, ethane-1,2-diyl, ethane-1,1-diyl, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,2-diyl.

[0331] In formula (b21a), as R 27a or R 28aAn alkylene group having 2 to 6 carbon atoms, examples thereof include ethane-1,2-diyl, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,2-diyl, pentane-1,5-diyl, pentane-1,3-diyl, pentane-1,4-diyl, pentane-2,3-diyl, hexane-1,6

[0332] -diyl, hexane-1,2-diyl, hexane-1,3-diyl, hexane-1,4-diyl, hexane-2,5-diyl, hexane-2,4-diyl, hexane-3,4-diyl.

[0333] In formula (b21a), R 27a or R 28a When it is an alkylene group having 2 to 6 carbon atoms substituted by 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 alkylene group substituted by a halogen atom include tetrafluoroethane-1,2-diyl, 1,1-difluoroethane-1,2-diyl, 1-fluoroethane-1,2-diyl, 1,2-difluoroethane-1,2-diyl, hexafluoropropane-1,3-diyl, 1,1,2,2-tetrafluoropropane-1,3-diyl, 1,1,2,2-tetrafluoropentane-1,5-diyl.

[0334] In formula (b21a), as R 27a or R 28a Examples when it is an arylene group include 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,5-dimethyl-1,4-phenylene, biphenyl-4,4'-diyl, diphenylmethane-4,4'-diyl, 2,2-diphenylpropane-4,4'-diyl, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl.

[0335] In formula (b21a), R 27a or R 28a When it is an arylene group substituted by 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 by a halogen atom include 2,3,5,6-tetrafluoro-1,4-phenylene.

[0336] In formula (b21a), as R 29aThe alkyl group having 1 to 18 carbon atoms which may have a branched chain includes methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, n-hexyl, hexan-2-yl, hexan-3-yl, n-heptyl, heptan-2-yl, heptan-3-yl, isoheptyl, tert-heptyl, n-octyl, isooctyl, tert-octyl, 2-ethylhexyl, n-nonyl, isononyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl.

[0337] In formula (b21a), R 29a When it is an alkyl group having 1 to 18 carbon atoms substituted by 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 by a halogen atom include trifluoromethyl, pentafluoroethyl, heptafluoro-n-propyl, nonafluoro-n-butyl, tridecafluoro-n-hexyl, heptadecafluoro-n-octyl, 2,2,2-trifluoroethyl, 1,1-difluoroethyl, 1,1-difluoro-n-propyl, 1,1,2,2-tetrafluoro-n-propyl, 3,3,3-trifluoro-n-propyl, 2,2,3,3,3-pentafluoro-n-propyl, 1,1,2,2-tetrafluorotetradecyl.

[0338] 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 1 hydrogen atom from these alicyclic hydrocarbons is preferred.

[0339] In formula (b21a), R 29a When it is an aryl group, a halogenated aryl group, an aralkyl group or a halogenated aralkyl group, preferred examples of these groups are the same as those of R 22a in the case of these groups.

[0340] Among the groups represented by formula (b21a), a preferred group is a group obtained by substituting a fluorine atom for the carbon atom bonded to the sulfur atom in the group represented by R 27a The carbon atom number of this preferred group is preferably 2 or more and 18 or less.

[0341] As R 22a , a perfluoroalkyl group having 1 to 8 carbon atoms is preferred. In addition, from the viewpoint of easily forming a high-precision resist pattern, camphor-10-yl is also preferred as R 22a .

[0342] In formula (b21), R 23a ~R 26a is a hydrogen atom or a monovalent organic group. Additionally, R 23a and R 24a , R 24a and R 25a , or R 25a and R 26a can each bond to one another to form a ring. For example, R 24a and R 25a can bond to form a 5-membered ring together with the naphthalene ring, thereby forming an acenaphthene skeleton.

[0343] As the monovalent organic group, it is preferably: an alkyl group or an alkoxy group having 4 to 18 carbon atoms which may be substituted by an alicyclic hydrocarbon group, a heterocyclyl group or a halogen atom and may have a branched chain; a heterocyclyloxy group; an alkylthio group having 4 to 18 carbon atoms which may be substituted by an alicyclic hydrocarbon group, a heterocyclyl group or a halogen atom and may have a branched chain; a heterocyclylthio group.

[0344] Additionally, a group obtained by replacing a methylene group at any position not adjacent to the oxygen atom of the alkoxy group with -CO- is also preferred.

[0345] A group obtained by interrupting the alkoxy group with an -O-CO- bond or an -O-CO-NH- bond is also preferred. It should be noted that the left end of the -O-CO- bond and the -O-CO-NH- bond is the side closer to the naphthalenedicarboxylic acid mother nucleus in the alkoxy group.

[0346] Furthermore, an alkylthio group having 4 to 18 carbon atoms which may be substituted by an alicyclic hydrocarbon group, a heterocyclyl group or a halogen atom and may have a branched chain is also preferably used as R 23a ~R 26a .

[0347] A group obtained by replacing a methylene group at any position not adjacent to the sulfur atom of the alkylthio group with -CO- is also preferred.

[0348] A group obtained by interrupting the alkylthio group with an -O-CO- bond or an -O-CO-NH- bond is also preferred. It should be noted that the left end of the -O-CO- bond and the -O-CO-NH- bond is the side closer to the naphthalenedicarboxylic acid mother nucleus in the alkylthio group.

[0349] As R 23a ~R 26a , preferably, R 23a is an organic group and R 24a ~R 26a are hydrogen atoms, or R 24ais an organic group and R 23a , R 25a , and R 26a are hydrogen atoms. Additionally, R 23a to R 26a may also all be hydrogen atoms.

[0350] As examples of the case where R 23a to R 26a is an unsubstituted alkyl group, examples include n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, n-hexyl, n-heptyl, isoheptyl, tert-heptyl, n-octyl, isooctyl, tert-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl.

[0351] As examples of the case where R 23a to R 26a is an unsubstituted alkoxy group, examples include n-butoxy, sec-butoxy, tert-butoxy, isobutoxy, n-pentyloxy, isopentyloxy, tert-pentyloxy, n-hexyloxy, n-heptyloxy, isoheptyloxy, tert-heptyloxy, n-octyloxy, isooctyloxy, tert-octyloxy, 2-ethylhexyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy.

[0352] As examples of the case where R 23a to R 26a is an unsubstituted alkylthio group, examples include n-butylthio, sec-butylthio, tert-butylthio, isobutylthio, n-pentylthio, isopentylthio, tert-pentylthio, n-hexylthio, n-heptylthio, isoheptylthio, tert-heptylthio, n-octylthio, isooctylthio, tert-octylthio, 2-ethylhexylthio, n-nonylthio, n-decylthio, n-undecylthio, n-dodecylthio, n-tridecylthio, n-tetradecylthio, n-pentadecylthio, n-hexadecylthio, n-heptadecylthio, n-octadecylthio.

[0353] When R 23a to R 26a is an alkyl, alkoxy, or 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 1 hydrogen atom from these alicyclic hydrocarbons is preferred.

[0354] In the case where R 23a ~R 26a is an alkyl group, an alkoxy group or an alkylthio group substituted with a heterocyclic group, or when R 23a ~R 26a is a heterocyclic oxy group, examples of the heterocyclic ring that forms the main skeleton of the heterocyclic group or the heterocyclic oxy 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, 4-pyrindine, indolizine, indole, indazole, purine, quinoxaline, isoquinoline, quinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, peridine, phenanthroline, carbazole, carboline, phenazine, anthyridine, thiadiazole, oxadiazole, triazine, triazole, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzothiadiazole, benzofurazan, naphthimidazole, benzotriazole, tetrazaindene. In addition, saturated heterocyclic rings obtained by hydrogenating the rings having conjugated bonds in these heterocyclic rings are also preferred.

[0355] As the heterocyclic group contained in the heterocyclic group or the heterocyclic oxy group that substitutes the alkyl group, the alkoxy group or the alkylthio group, a group obtained by removing one hydrogen atom from the above-mentioned heterocyclic ring is preferred.

[0356] As R 23a ~R 26a Examples of the case where it is an alkoxy group containing an alicyclic hydrocarbon group include cyclopentyloxy, methylcyclopentyloxy, cyclohexyloxy, fluorocyclohexyloxy, chlorocyclohexyloxy, cyclohexylmethyloxy, methylcyclohexyloxy, norbornyloxy, ethylcyclohexyloxy, cyclohexylethyloxy, dimethylcyclohexyloxy, methylcyclohexylmethyloxy, norbornylmethyloxy, trimethylcyclohexyloxy, 1-cyclohexylbutyloxy, adamantyloxy, menthyloxy, n-butylcyclohexyloxy, tert-butylcyclohexyloxy, bornyloxy, isobornyloxy, decahydronaphthyloxy, dicyclopentadienyloxy, 1-cyclohexylpentyloxy, methyladamantyloxy, adamantylmethyloxy, 4-pentylcyclohexyloxy, cyclohexylcyclohexyloxy, adamantylethyloxy, dimethyladamantyloxy.

[0357] As R 23a ~R 26a Examples of the case where it is a heterocyclic oxy group include tetrahydrofuranyloxy, furanyloxy, tetrahydrofuranyloxy, tetrahydropyranyloxy, butyryloxy, indolyloxy.

[0358] As R23a ~R 26a Examples in the case of an alkylthio group containing an alicyclic hydrocarbon group include cyclopentylthio, cyclohexylthio, cyclohexylmethylthio, norbornylthio, and isonorbornylthio.

[0359] As R 23a ~R 26a Examples in the case of a heterocyclic group thio include furfurylthio and tetrahydrofurylthio.

[0360] As R 23a ~R 26a Examples in the case of a group in which a methylene group at an arbitrary position not adjacent to the oxygen atom of the alkoxy group is replaced by -CO- include 2-oxobutyl-1-oxy, 2-oxopentyl-1-oxy, 2-oxohexyl-1-oxy, 2-oxoheptyl-1-oxy, 2-oxooctyl-1-oxy, 3-oxobutyl-1-oxy, 4-oxopentyl-1-oxy, 5-oxohexyl-1-oxy, 6-oxoheptyl-1-oxy, 7-oxooctyl-1-oxy, 3-methyl-2-oxopentane-4-oxy, 2-oxopentane-4-oxy, 2-methyl-2-oxopentane-4-oxy, 3-oxoheptane-5-oxy, and 2-adamantanone-5-oxy.

[0361] As R 23a ~R 26a Examples in the case of a group in which a methylene group at an arbitrary position not adjacent to the sulfur atom of the alkylthio group is replaced by -CO- include 2-oxobutyl-1-thio, 2-oxopentyl-1-thio, 2-oxohexyl-1-thio, 2-oxoheptyl-1-thio, 2-oxooctyl-1-thio, 3-oxobutyl-1-thio, 4-oxopentyl-1-thio, 5-oxohexyl-1-thio, 6-oxoheptyl-1-thio, 7-oxooctyl-1-thio, 3-methyl-2-oxopentane-4-thio, 2-oxopentane-4-thio, 2-methyl-2-oxopentane-4-thio, and 3-oxoheptane-5-thio.

[0362] Specific examples of the compound represented by the formula (b21) include the following compounds.

[0363] [Chemical formula 35]

[0364]

[0365] [Chemical formula 37]

[0366]

[0367] [Chemical formula 38]

[0368]

[0369] [Chemical formula 39]

[0370]

[0371] [Chemical formula 40]

[0372]

[0373] [Chemical formula 41]

[0374]

[0375] [Chemical formula 42]

[0376]

[0377] [Chemical formula 43]

[0378]

[0379] [Chemical formula 44]

[0380]

[0381] The photoacid generator (B) can be used alone or in combination of two or more. In addition, relative to the total solid content of the photosensitive resin composition, the content of the photoacid generator (B) is preferably set to 0.1% by mass or more and 10% by mass or less, more preferably set to 0.2% by mass or more and 6% by mass or less, and particularly preferably set to 0.5% by mass or more and 6% by mass or less. By setting the usage amount of the photoacid generator (B) within the above range, it is easy to prepare a photosensitive resin composition with good sensitivity, a uniform solution, and excellent storage stability.

[0382] <Acid diffusion control agent (C)>

[0383] The photosensitive resin composition preferably contains an acid diffusion control agent (C). The acid diffusion control agent (C) is not particularly limited. The acid diffusion control agent (C) can improve the shape of the resist pattern, the placement stability of the photosensitive resin composition layer, etc.

[0384] As the acid diffusion control agent (C), trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tri-n-amylamine (tributylamine), 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-tris(2-pyridyl)-S-triazine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, pyridine, 2,6-di-tert-butylpyridine, etc. can be cited. They can be used alone or in combination of two or more kinds.

[0385] Relative to 100 parts by mass of the resin (A), the acid diffusion control agent (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.

[0386] <Solvent (S)>

[0387] The photosensitive resin composition contains a solvent (S). The type of the solvent (S) is not particularly limited as long as it does not hinder the object of the present invention, and it can be appropriately selected and used from the organic solvents conventionally used for photosensitive resin compositions.

[0388] Specific examples of the solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols and their derivatives such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and dipropylene glycol monoacetate, and their monomethyl ethers, monoethyl ethers, monopropyl ethers, monobutyl ethers, and monophenyl ethers; cyclic ethers such as dioxane; esters such as ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, and 3-methyl-3-methoxybutyl acetate; aromatic hydrocarbons such as toluene and xylene; and the like. They may be used alone or in combination of two or more.

[0389] The content of the solvent (S) is not particularly limited as long as the object of the present invention is not hindered. It is preferably used in the 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.

[0390] <Other components>

[0391] In order to improve the plasticity of the formed film, the photosensitive resin composition may further contain a polyvinyl resin. 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.

[0392] In order to improve the adhesion to the support, the photosensitive resin composition may further contain an adhesion aid.

[0393] In order to improve coatability, defoaming property, leveling property, etc., the photosensitive resin composition may further contain a surfactant. Specific examples of the surfactant include BM-1000, BM-1100 (both manufactured by BM CHEMI), MEGAFACE F142D, MEGAFACE F172, MEGAFACE F173, MEGAFACE F183 (all manufactured by DIC), Fluorad FC-135, Fluorad FC-170C, Fluorad FC-430, Fluorad FC-431 (all manufactured by Sumitomo 3M), Surflon S-112, Surflon S-113, Surflon S-131, Surflon S-141, Surflon S-145 (all manufactured by Asahi Glass), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (all manufactured by Toray Silicone), PolyFox PF-136A, PolyFox PF-156A, PolyFox PF-151N, PolyFox PF-636, PolyFox PF-656, PolyFox PF-6520 (all manufactured by OMNOVA Solutions), and other commercially available fluorosurfactants, but are not limited thereto.

[0394] In order to finely adjust the solubility in the developer, the photosensitive resin composition may further contain an acid or an acid anhydride.

[0395] Specific examples of the acid and the acid anhydride include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, and 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, and syringic acid; polycarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, butanetetracarboxylic acid, trimellitic acid, pyromellitic acid, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid; acid anhydrides such as itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenylsuccinic anhydride, malonic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, nadic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bis(trimellitate), and glycerol tris(trimellitate); and so on.

[0396] <Method for Preparing Photosensitive Resin Composition>

[0397] The photosensitive resin composition can be prepared by mixing and stirring the above components using a conventional method. 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 can be further filtered using a sieve, a membrane filter, etc.

[0398] <Method for Manufacturing Microlens>

[0399] The method for manufacturing a microlens includes the following steps: a step of coating a photosensitive resin composition on 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 in position (hereinafter also referred to as the exposure step); a step of developing the exposed photosensitive resin composition layer (hereinafter also referred to as the developing 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 forming 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).

[0400] [Coating Step]

[0401] In the coating step, a photosensitive resin composition is coated on a lens material layer to form a photosensitive resin composition layer.

[0402] As the lens material layer, a lens material layer having an etching rate of 110 nm / min or more based on the plasma obtained from CF 4 gas is preferably used, and a lens material layer having an etching rate of 140 nm / min or more is more preferably used. 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 using the above photosensitive resin composition is relatively fast, even for a lens material layer within the above numerical range, it is easy to transfer the shape of the desired lens pattern. In this specification, the so-called etching rate refers to the etching rate in the case of performing CF 4 plasma etching under the conditions described in the following examples.

[0403] Examples of the polymer used in the lens material layer within the above numerical range include polymers having a triazine skeleton, etc.

[0404] The method for forming the photosensitive resin composition layer is not particularly limited, and conventionally known methods can be used. In the case where the photosensitive resin composition is a solid or a highly viscous gel, for example, the photosensitive resin composition layer can be formed by supplying a specified amount of the photosensitive resin composition onto the lens material layer and then applying pressure while appropriately heating the photosensitive resin composition. In the case where the photosensitive resin composition is a liquid (for example, when the photosensitive resin composition contains a solvent (S)), for example, contact transfer type coating devices such as a roll coater, a reverse roll coater, a bar coater, and a slot coater, or non-contact type coating devices such as a spinner (rotary coating device) and a curtain coater can be used to coat the photosensitive resin composition onto the lens material layer so as to achieve a desired film thickness, and then appropriately perform a heat treatment (pre-baking (PAB) treatment) to remove the organic solvent, thereby forming the photosensitive resin composition layer.

[0405] The conditions of the above heat treatment vary depending on the types of the respective components in the photosensitive resin composition, the mixing 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).

[0406] The film thickness of the photosensitive resin composition layer is preferably in the range of 100 nm to 4.0 μm, more preferably in the range of 200 nm to 2.0 μm.

[0407] <Exposure step>

[0408] 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.

[0409] In addition, by appropriately adjusting the composition of the photosensitive resin composition, exposure can also be performed using 2 radiations such as an F excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, and soft X-ray.

[0410] After exposure, PEB treatment (post-exposure heat treatment) is appropriately performed. The conditions of the PEB treatment vary depending on the types of the respective components in the composition, the mixing ratio, the coating film thickness, etc. 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).

[0411] [Development step]

[0412] In the developing step, the exposed positive photosensitive resin composition layer is developed. Thereby, unnecessary portions are dissolved and removed.

[0413] As the developer, for example, an aqueous solution of bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonane, etc. can be used. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol and ethanol and a surfactant to the aqueous solution of the above bases can also be used as the developer. As the developer, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide is preferred.

[0414] Although the development time also varies depending on the composition of the photosensitive resin composition, the film thickness of the photosensitive resin composition layer, etc., it is usually 1 to 30 minutes. The development method can be any method such as the puddle method, dipping method, spin-dip method, spray development method, etc.

[0415] After development, running water washing is appropriately performed for 30 to 90 seconds, and drying is performed using an air gun, an oven, etc.

[0416] <Mask layer formation step>

[0417] In the mask layer formation step, the developed photosensitive resin composition layer is heated to form a mask layer having a microlens pattern.

[0418] The heating conditions vary depending on the types of the respective components in the photosensitive resin composition, the mixing ratio, the coating film thickness, etc. 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).

[0419] <Shape transfer step>

[0420] In the shape transfer step, the lens material layer and the mask layer are dry-etched, and the shape of the microlens pattern is transferred to the lens material layer. Thereby, microlenses can be obtained from the lens material layer.

[0421] As the dry etching, there is no particular limitation. For example, dry etching using plasma (oxygen, argon, CF 4 etc.), corona discharge, etc. can be mentioned.

[0422] Note that when performing this process, it is preferable to adjust the etching rate ratio of the mask layer to the lens material layer within the range of 0.75 to 1.25. By making such an adjustment, it becomes easier to transfer the shape of the desired lens pattern.

[0423] The preferred range of the etching rate of the mask layer is the same as that of the above-mentioned lens material layer.

[0424] Examples

[0425] The present invention will be described in more detail based on examples, but the present invention is not limited by these examples.

[0426] [Examples 1 to 5, Comparative Example 1, and Comparative Example 2]

[0427] The components of the types and amounts described in Table 1 were uniformly dissolved in a solvent so that the solid component concentration became 8% by mass to prepare a photosensitive resin composition. The numerical values in the composition in Table 1 represent the blending amounts of the respective components (unit: parts by mass). As the solvent, a mixed solvent having a mass ratio of propylene glycol monomethyl ether acetate (PGMEA) to propylene glycol monomethyl ether of 60:40 was used. In addition, the components used in the examples and comparative examples are as follows.

[0428] A-1: Resin represented by the following formula (weight average molecular weight Mw: 12000, dispersity: 1.66, x = 30, y = 50, z = 20, Ohnishi parameter: 3.734, ring parameter: 0.421)

[0429] [Chemical formula 45]

[0430]

[0431] A-2: Resin represented by the following formula (weight average molecular weight Mw: 12000, dispersity: 1.54, x = 50, y = 50, Ohnishi parameter: 4.167, ring parameter: 0.319)

[0432] [Chemical formula 46]

[0433]

[0434] A-3: Resin represented by the following formula (weight average molecular weight Mw: 6000, dispersity: 1.66, x = 30, y = 50, z = 20, Ohnishi parameter: 3.734, ring parameter: 0.421)

[0435] [Chemical formula 47]

[0436]

[0437] Resin represented by the following formula (weight average molecular weight Mw: 20,000, dispersity: 1.10, x = 35, y = 65, Onishi parameter: 2.693, ring parameter: 0.495)

[0438] [Chemical formula 48]

[0439]

[0440] A-5: Resin represented by the following formula (weight average molecular weight Mw: 6,000, dispersity: 2.62, x = 40, y = 60, Onishi parameter: 4.077, ring parameter: 0.207)

[0441] [Chemical formula 49]

[0442]

[0443] B-1: Compound represented by the following formula

[0444] [Chemical formula 50]

[0445]

[0446] B-2: Compound represented by the following formula

[0447] [Chemical formula 51]

[0448]

[0449] B-3: Compound represented by the following formula

[0450] [Chemical formula 52]

[0451]

[0452] C-1: Compound represented by the following formula

[0453] [Chemical formula 53]

[0454]

[0455] C-2: Compound represented by the following formula

[0456] [Chemical formula 54]

[0457]

[0458] <Evaluation>

[0459] For the photosensitive resin compositions obtained in the examples and comparative examples, evaluation was carried out through the following items.

[0460] (KrF patterning)

[0461] On a substrate (which is obtained by forming an antireflection film (film thickness: 0.16 μm) and an organic underlayer film (film thickness: 1.0 μm) on a Si substrate), a photosensitive resin composition prepared in an example or a comparative example was applied using a spin coater to form a coating film. For the above coating film, a pre-baking treatment was performed on a hot plate at 100 °C for 60 seconds to dry the above coating film, thereby forming a photosensitive resin composition layer with a film thickness of 300 nm.

[0462] Next, using a KrF exposure apparatus NSR-S203B (manufactured by Nikon Corporation, NA = 0.68, S = 0.75), KrF excimer laser (wavelength: 248 nm) was selectively irradiated onto the above photosensitive resin composition layer through a mask (dot: 0.42 μm × 0.42 μm, pitch: 0.22 μm). The exposure dose here was set to 50 mJ / cm 2 .

[0463] Then, for the above photosensitive resin composition layer, a PEB treatment was performed at 120 °C for 90 seconds, and then, development was carried out at 23 °C for 60 seconds using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide.

[0464] The case where a pattern was formed under the above conditions was denoted as A, and the case where no pattern was formed was denoted as B. The results are shown in Table 1.

[0465] (ArF patterning)

[0466] On a substrate (which is obtained by forming an antireflection film (film thickness: 0.16 μm) and an organic underlayer film (film thickness: 1.0 μm) on a Si substrate), a photosensitive resin composition prepared in an example or a comparative example was applied using a spin coater to form a coating film. For the above coating film, a pre-baking treatment was performed on a hot plate at 120 °C for 60 seconds to dry the above coating film, thereby forming a photosensitive resin composition layer with a film thickness of 200 nm.

[0467] Next, using an ArF exposure apparatus NSR-S308F (manufactured by Nikon Corporation, NA = 0.60, S = 0.75), ArF excimer laser (wavelength: 193 nm) was selectively irradiated onto the above photosensitive resin composition layer through a mask (dot: 0.4 μm × 0.4 μm, pitch: 0.2 μm). The exposure dose here was set to 10 mJ / cm 2 .

[0468] Then, for the above photosensitive resin composition layer, a PEB treatment was performed at 110 °C for 60 seconds, and then, development was carried out at 23 °C for 65 seconds using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide.

[0469] The case where a pattern is formed under the above conditions is denoted as A, and the case where no pattern is formed is denoted as B. The results are shown in Table 1.

[0470] (Etching rate)

[0471] On a Si substrate, a photosensitive resin composition prepared in an example or a comparative example is applied using a spin coater to form a coating film. For the above coating film, a pre-baking treatment is performed on a hot plate at 100 °C for 60 seconds to dry the above coating film, thereby forming a photosensitive resin composition layer with a film thickness of 1 μm.

[0472] For this photosensitive resin composition layer, under the following conditions, dry etching is performed using plasma obtained from CF 4 gas (CF 4 plasma etching).

[0473] <CF 4 Plasma etching conditions>

[0474] Apparatus: High-vacuum RIE apparatus (TCA-3822 manufactured by Tokyo Ohka Kogyo Co., Ltd.)

[0475] Gas: CF 4 gas

[0476] Gas flow rate: 300 mL / min

[0477] Temperature inside the chamber: 60 °C

[0478] Pressure inside the chamber: 40 Pa

[0479] Output power (RF) applied to generate plasma: 800 W

[0480] Processing time: 2 minutes, 3 minutes, 5 minutes, or 7 minutes

[0481] The etching rate (the thickness of the film etched per unit time) is obtained from the difference in the film thickness of the photosensitive resin composition layer before and after etching. Using this etching rate as an index, evaluation is performed according to the following criteria. The results are shown in Table 1.

[0482] A + : Etching rate is greater than 140 nm / min

[0483] A: Etching rate is greater than 120 nm / min and 140 nm / min or less

[0484] B: Etching rate is 120 nm / min or less

[0485] (Heat fluidity)

[0486] For the patterns formed in the above evaluation of KrF patterning, post-baking treatment was performed for 300 seconds at each temperature. The cross-section of the pattern was observed using SEM, and the lowest temperature at which a microlens pattern shape could be obtained was determined, and the evaluation was performed according to the following criteria. The results are shown in Table 1. It should be noted that in Comparative Example 2, no pattern was formed in KrF patterning, so the evaluation of heat fluidity was not performed.

[0487] A: 140 °C or higher and 170 °C or lower

[0488] B: 110 °C or higher and lower than 140 °C, or higher than 170 °C and 200 °C or lower

[0489] C: lower than 110 °C, or higher than 200 °C

[0490] [Table 1]

[0491]

[0492] As shown in Table 1, it can be seen that if the photosensitive resin composition contains a resin (A) having a specific structural unit, a photoacid generator (B), and a solvent (S), a fine and high-etching-rate microlens pattern can be formed 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 dry-etching mask layer on a lens material layer.

Claims

1. A photosensitive resin composition for forming a microlens pattern as a mask layer for dry etching on a lens material layer, The photosensitive resin composition contains a resin (A), a photoacid generator (B) and a solvent (S). The resin (A) comprises: a structural unit (a1) derived from a (meth)acrylate, containing an acid-dissociable dissolution-inhibiting group and capable of increasing solubility in a base by the action of an acid; and a structural unit (a2) containing a residue-inhibiting group.

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 formulae (a1-1) to (a1-3), [Chemical formula 1] In 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 fluoroalkyl group having 1 to 6 carbon atoms, R 15b ~R 17b Each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched fluoroalkyl group having 1 to 6 carbon atoms, or an aliphatic cyclic group having 5 to 20 carbon atoms, and R 16b and R 17b can be bonded to each other to form a hydrocarbon ring having 5 to 20 carbon atoms together with the carbon atoms to which they are bonded, 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 photosensitive resin composition according to claim 1 or 2, wherein The residue suppressing group is a cyclic group containing a lactone or a cyclic group containing -SO2-.

4. A method for manufacturing a microlens, comprising the following steps: A step of coating 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 to light; 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.

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

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