Chemically amplified positive-type photosensitive composition, photosensitive dry film, method for producing patterned resist film, method for producing substrate with mold, and method for producing plated object

Abstract

To provide a chemically amplified positive photosensitive composition that has a high solid content and excellent storage stability and can form a photosensitive layer less prone to developer rejection and swelling and having excellent crack resistance; a photosensitive dry film having a photosensitive layer composed of the chemically amplified positive photosensitive composition; a method for producing a patterned resist film by using the chemically amplified positive photosensitive composition; a method for producing a cast substrate; and a method for producing a plated molding.SOLUTION: A chemically amplified positive photosensitive composition contains an acid generator (A) that generates an acid by irradiation with active rays or radiation and a resin (B) that shows increased solubility to alkali by the action of an acid. The resin (B) contains an acrylic resin (B3). The acrylic resin (B3) contains a specific constitutional unit. The solid content is 25 mass% or more and 50 mass% or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a chemically amplified positive-tone photosensitive composition, a photosensitive dry film having a photosensitive layer made of the chemically amplified positive-tone photosensitive composition, a method for producing a patterned resist film using the aforementioned chemically amplified positive-tone photosensitive composition, a method for producing a substrate with a mold, and a method for producing a plated object. [Background technology]

[0002] At present, photofabrication is the mainstream of precision micromachining technology. Photofabrication is a general term for a technology in which a photoresist composition is applied to the surface of a workpiece to form a photoresist layer, the photoresist layer is patterned by photolithography technology, and the patterned photoresist layer (photoresist pattern) is used as a mask to perform chemical etching, electrolytic etching, or electroforming mainly involving electroplating, to manufacture various precision parts such as semiconductor packages.

[0003] In recent years, with the downsizing of electronic devices, high-density mounting technology for semiconductor packages has advanced, with efforts being made to increase the mounting density by implementing multi-pin thin-film mounting of packages, miniaturizing package size, and using two-dimensional mounting technology and three-dimensional mounting technology with the flip chip method. In such high-density mounting technology, for example, protruding electrodes (mounting terminals) such as bumps protruding from the package, and metal posts that connect rewiring extending from peripheral terminals on the wafer to the mounting terminals are arranged with high precision on the substrate as connection terminals.

[0004] Photoresist compositions are used in the above-mentioned photofabrication, and chemically amplified photosensitive compositions containing an acid generator are known as such photoresist compositions (see Patent Documents 1 and 2, etc.). In chemically amplified photosensitive compositions, an acid is generated from an acid generator upon irradiation (exposure), and diffusion of the acid is promoted by heat treatment, causing an acid-catalyzed reaction with the base resin in the composition, etc., and changing its alkali solubility.

[0005] Such chemically amplified photosensitive compositions are used for forming patterned insulating films and etching masks, as well as for forming plated objects such as bumps, metal posts, and Cu rewiring by plating processes. Specifically, a photoresist layer of a desired thickness is formed on a support such as a metal substrate using the chemically amplified photosensitive composition, and exposed through a predetermined mask pattern, and developed to form a photoresist pattern used as a mold in which the portion forming the plated object is selectively removed (peeled off). Then, a conductor such as copper is embedded in the removed portion (non-resist portion) by plating, and then the photoresist pattern around it is removed to form bumps, metal posts, and Cu rewiring. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-176112 [Patent Document 2] Japanese Patent Application Publication No. 11-52562 Summary of the Invention [Problem to be solved by the invention]

[0007] When a photoresist layer (photosensitive layer) to be formed is thick, a chemically amplified photosensitive composition having a high solid content concentration may be used. However, conventional chemically amplified photosensitive compositions have a problem in that they have poor storage stability when the solid content concentration is high. If the storage stability of a chemically amplified photosensitive composition is poor, for example, the viscosity of the chemically amplified photosensitive composition increases over time.

[0008] In addition, when a conventional chemically amplified photosensitive composition is used, there is a problem that the photoresist layer may repel the developer during development. If the developer is repelled, the developer cannot be brought into sufficient contact with the photosensitive layer, resulting in defective pattern formation, such as the occurrence of areas where the resist pattern is not formed, or the formed resist pattern not having the desired shape.

[0009] In addition, when a conventional positive-type chemically amplified photosensitive composition is used, there is a problem that the photoresist layer may swell during development when the exposed photoresist layer comes into contact with a developer. When the photoresist layer swells during development, the unexposed area may dissolve. In addition, when the photoresist layer swells during development, wrinkles due to swelling may be observed in the unexposed area in the formed resist pattern, or floating or distortion due to swelling may be observed.

[0010] In addition, when a conventional positive-type chemically amplified photosensitive composition is used, there is a problem that cracks may be formed in the resist pattern formed. If cracks are formed in the resist pattern, for example, when the resist pattern is used as a mold for forming a plated object, it is difficult to form a plated object of a desired shape. Therefore, it is also desired that the chemically amplified photosensitive composition suppresses the occurrence of cracks, that is, has excellent crack resistance.

[0011] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a chemically amplified positive-type photosensitive composition capable of forming a photosensitive layer having a high solids concentration, good storage stability, and excellent crack resistance due to suppressed developer repellency and swelling, a photosensitive dry film having a photosensitive layer made of the chemically amplified positive-type photosensitive composition, a method for producing a patterned resist film using the aforementioned chemically amplified positive-type photosensitive composition, a method for producing a substrate with a mold, and a method for producing a plated object. [Means for solving the problem]

[0012] As a result of intensive research into achieving the above object, the present inventors have found that the above problems can be solved by a chemically amplified positive-type photosensitive composition comprising an acid generator (A) that generates an acid when irradiated with actinic rays or radiation, and a resin (B) whose solubility in alkali increases under the action of an acid, the resin (B) comprising an acrylic resin (B3), the acrylic resin (B3) comprising a structural unit represented by the following formula (B3-1), and having a solids concentration of 25% by mass or more and 70% by mass or less, thereby completing the present invention. Specifically, the present invention provides the following:

[0013] A first aspect of the present invention is a composition comprising an acid generator (A) that generates an acid when irradiated with actinic rays or radiation, and a resin (B) whose solubility in an alkali increases under the action of the acid, The resin (B) contains an acrylic resin (B3), The acrylic resin (B3) is represented by the following formula (B3-1): [ka] (In formula (B3-1), R b01 is -O-, -S-, -CO-O-, -CO-NH-, or -SO2-; R b02 and R b03 are each independently a hydrogen atom or an organic group; R b02 and R b03 At least one of -CO-OR b04 R b04 is a hydrogen atom or an organic group, and x1 and x2 are each independently 1 or 2. The structural unit represented by The chemically amplified positive photosensitive composition has a solid content concentration of 25% by mass or more and 70% by mass or less.

[0014] A second aspect of the present invention is a photosensitive dry film having a base film and a photosensitive layer formed on the surface of the base film, the photosensitive layer being made of the chemically amplified positive-type photosensitive composition according to the first aspect.

[0015] A third aspect of the present invention is A lamination step of laminating a photosensitive layer made of the chemically amplified positive-type photosensitive composition according to the first embodiment on a substrate; an exposure step of position-selectively irradiating the photosensitive layer with actinic rays or radiation; and a developing step of developing the photosensitive layer after exposure.

[0016] A fourth aspect of the present invention is A lamination step of laminating a photosensitive layer made of the chemically amplified positive-type photosensitive composition according to the first aspect on a substrate having a metal surface; an exposure step of irradiating the photosensitive layer with actinic rays or radiation; and a development step of developing the exposed photosensitive layer to create a mold for forming a plated object.

[0017] A fifth aspect of the present invention is a method for producing a plated object, comprising a step of plating a mold-mounted substrate produced by the method for producing a mold-mounted substrate relating to the fourth aspect, to form a plated object within the mold. Effect of the Invention

[0018] According to the present invention, it is possible to provide a chemically amplified positive-type photosensitive composition capable of forming a photosensitive layer having a high solids concentration, good storage stability, and suppressed developer repelling and swelling, and excellent crack resistance; a photosensitive dry film having a photosensitive layer made of the chemically amplified positive-type photosensitive composition; a method for producing a patterned resist film using the aforementioned chemically amplified positive-type photosensitive composition; a method for producing a substrate with a mold; and a method for producing a plated object. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] <Chemically amplified positive-type photosensitive composition> The chemically amplified positive-type photosensitive composition (hereinafter also referred to as photosensitive composition) contains an acid generator (A) (hereinafter also referred to as acid generator (A)) that generates an acid when irradiated with actinic rays or radiation, and a resin (B) (hereinafter also referred to as resin (B)) whose solubility in alkali increases due to the action of acid. The resin (B) contains an acrylic resin (B3), and the acrylic resin (B3) contains a structural unit represented by the following formula (B3-1). The photosensitive resin composition may contain components such as an acid diffusion inhibitor (C), an alkali-soluble resin (D), a sulfur-containing compound (E), a dye (F), and an organic solvent (S) as necessary. The chemically amplified positive photosensitive composition has a solid content concentration of 25% by mass or more and 70% by mass or less. When the solid content concentration is within this range, a thick photosensitive layer is easily formed. The solid content concentration of the photosensitive composition may be 30% by mass or more and 60% by mass or less, or 40% by mass or more and 50% by mass or less. The solid content refers to components other than the organic solvent (S) and water.

[0020] Essential and optional components contained in the photosensitive composition and a method for producing the photosensitive composition will be described below.

[0021] <Acid Generator (A)> The acid generator (A) is a compound that generates an acid by irradiation with actinic rays or radiation, and is not particularly limited as long as it is a compound that generates an acid directly or indirectly by light. The acid generator (A) is preferably an acid generator of the first to fifth embodiments described below. Hereinafter, preferred ones of the acid generators (A) that are preferably used in the positive photosensitive composition will be described as the first to fifth embodiments.

[0022] A first embodiment of the acid generator (A) is a compound represented by the following formula (a1).

[0023] [ka]

[0024] In the above formula (a1), X 1arepresents a sulfur atom or an iodine atom with a valence of g, where g is 1 or 2. h represents the number of repeating units of the structure in parentheses. R 1a X 1a 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 R may be substituted with at least one selected from the group consisting of alkyl, hydroxy, alkoxy, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, arylthiocarbonyl, acyloxy, arylthio, alkylthio, aryl, heterocyclic, aryloxy, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, alkyleneoxy, amino, cyano, nitro, and halogen. 1a The number of is g+h(g-1)+1, and R 1a may be the same or different from each other. 1a are directly connected to each other, or -O-, -S-, -SO-, -SO2-, -NH-, -NR 2a -, -CO-, -COO-, -CONH-, an alkylene group having 1 to 3 carbon atoms, or a phenylene group; 1a R 2a is an alkyl group having from 1 to 5 carbon atoms or an aryl group having from 6 to 10 carbon atoms.

[0025] X 2a is a structure represented by the following formula (a2).

[0026] [ka]

[0027] In the above formula (a2), X 4arepresents an alkylene group having 1 to 8 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a divalent group of a heterocyclic compound having 8 to 20 carbon atoms; X 4a X may be substituted with at least one selected from the group consisting of alkyl having 1 to 8 carbon atoms, alkoxy having 1 to 8 carbon atoms, aryl having 6 to 10 carbon atoms, hydroxy, cyano, nitro, and halogen. 5a -O-, -S-, -SO-, -SO2-, -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's 5a may be the same or different. 2a is as defined above.

[0028] X 3a- is a counter ion of the onium, and examples thereof include a fluorinated alkylfluorophosphate anion represented by the following formula (a17) or a borate anion represented by the following formula (a18).

[0029] [ka]

[0030] In the above formula (a17), R 3a represents an alkyl group in which 80% or more of the hydrogen atoms are substituted with fluorine atoms. j represents the number of R 3a may be the same or different.

[0031] [ka]

[0032] In the above formula (a18), R 4a ~R 7aeach independently represents a fluorine atom or a phenyl group, and some 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.

[0033] Examples of the onium ion in the compound represented by the above formula (a1) include triphenylsulfonium, tri-p-tolylsulfonium, 4-(phenylthio)phenyldiphenylsulfonium, 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)phenylbis (4-Fluorophenyl)sulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldiphenylsulfonium, 2-[(diphenyl)sulfonio]thioxanthone, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyldi-p-tolylsulfonium, 4-(4-benzoylphenylthio)phenyldiphenyl sulfonium, diphenylphenacylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 2-naphthylmethyl(1-ethoxycarbonyl)ethylsulfonium, 4-hydroxyphenylmethylphenacylsulfonium, phenyl[4-(4-biphenylthio)phenyl]4-biphenylsulfonium, phenyl[4-(4-biphenylthio)phenyl]3-biphenylsulfonium, [4-(4-acetophenylthio)phenyl]diphenylsulfonium, octadecylmethylphenacylsulfonium, diphenyliodonium, di-p-tolyliodonium, bis(4-dodecylphenyl)iodonium, bis(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyliodonium, bis(4-decyloxy)phenyliodonium, 4-(2-hydroxytetradecyloxy)phenylphenyliodonium, 4-isopropylphenyl(p-tolyl)iodonium, or 4-isobutylphenyl(p-tolyl)iodonium.

[0034] Of the onium ions in the compound represented by the above formula (a1), preferred onium ions include the sulfonium ion represented by the following formula (a19).

[0035] [ka]

[0036] In the above formula (a19), R 8a Each of X 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 alkyloxycarbonyl group, a halogen atom, an aryl group which may have a substituent, and an arylcarbonyl group which may have a substituent. 2a is X in the above formula (a1). 2a It has the same meaning as:

[0037] Specific examples of the sulfonium ion represented by the above formula (a19) include 4-(phenylthio)phenyldiphenylsulfonium, 4-(4-benzoyl-2-chlorophenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoylphenylthio)phenyldiphenylsulfonium, phenyl[4-(4-biphenylthio)phenyl]4-biphenylsulfonium, phenyl[4-(4-biphenylthio)phenyl]3-biphenylsulfonium, [4-(4-acetophenylthio)phenyl]diphenylsulfonium, and diphenyl[4-(p-terphenylthio)phenyl]diphenylsulfonium.

[0038] In the fluorinated alkyl fluorophosphate anion represented by the above formula (a17), R 3arepresents an alkyl group substituted with a fluorine atom, the number of carbon atoms being preferably 1 or more and 8 or less, more preferably 1 or more and 4 or less. 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 ratio of hydrogen atoms in the alkyl group substituted with fluorine atoms is usually 80% or more, preferably 90% or more, and more preferably 100%. If the substitution rate of fluorine atoms is less than 80%, the acid strength of the onium fluorinated alkyl fluorophosphate represented by the above formula (a1) is reduced.

[0039] Particularly preferred R 3a R is a linear or branched perfluoroalkyl group having 1 to 4 carbon atoms and a fluorine atom substitution rate of 100%, and specific examples include CF3, CF3CF2, (CF3)2CF, CF3CF2CF2, CF3CF2CF2CF2, (CF3)2CFCF2, CF3CF2(CF3)CF, and (CF3)3C. 3a The number j 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.

[0040] A specific example of a preferred fluorinated alkyl fluorophosphate anion is [(CF3CF2)2PF4] - , [(CF3CF2)3PF3] - , [((CF3)2CF)2PF4] - , [((CF3)2CF)3PF3] - , [(CF3CF2CF2)2PF4] - , [(CF3CF2CF2)3PF3] - , [((CF3)2CFCF2)2PF4] - , [((CF3)2CFCF2)3PF3] - , [(CF3CF2CF2CF2)2PF4] - , or [(CF3CF2CF2)3PF3] - Among these, [(CF3CF2)3PF3]- , [(CF3CF2CF2)3PF3] - , [((CF3)2CF)3PF3] - , [((CF3)2CF)2PF4] - , [((CF3)2CFCF2)3PF3] - , or [((CF3)2CFCF2)2PF4] - is particularly preferred.

[0041] A preferred example of the borate anion represented by the above formula (a18) is tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - ), tetrakis[(trifluoromethyl)phenyl]borate ([B(C6H4CF3)4] - ), difluorobis(pentafluorophenyl)borate ([(C6F5)2BF2] - ), trifluoro(pentafluorophenyl)borate ([(C6F5)BF3] - ), tetrakis(difluorophenyl)borate ([B(C6H3F2)4] - Among these, tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - ) is particularly preferred.

[0042] As a second embodiment of the acid generator (A), 2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-ethyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-propyl-2-furyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dimethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-diethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,5-dipropoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-ethoxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-propoxyphenyl)ethenyl]-s-triazine )ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-[2-(3,4-methylenedioxyphenyl)ethenyl]-s-triazine, 2,4-bis(trichloromethyl)-6-(3,4-methylenedioxyphenyl)-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)styrylphenyl-s-triazine riazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)styrylphenyl-s-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(2-furyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,5-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4-methylenedioxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, tris(1,3-dibromopropyl)-1,3,5-triazine, tris(2,3-dibromopropyl)-1,3,5-triazine, and halogen-containing triazine compounds represented by the following formula (a3), such as tris(2,3-dibromopropyl)isocyanurate, are included.

[0043] [ka]

[0044] In the above formula (a3), R 9a , R 10a , R 11a each independently represents a halogenated alkyl group.

[0045] Furthermore, examples of a third embodiment of the acid generator (A) 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 (a4) containing an oxime sulfonate group.

[0046] [ka]

[0047] In the above formula (a4), R 12a represents a monovalent, divalent, or trivalent organic group; R 13arepresents 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 the parentheses.

[0048] In the above formula (a4), examples of the aromatic group include aryl groups such as phenyl and naphthyl groups, and heteroaryl groups such as furyl and thienyl groups. These may have one or more suitable substituents on the ring, such as halogen atoms, alkyl groups, alkoxy groups, and nitro groups. 13a is particularly preferably an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, and a butyl group. 12a is an aromatic group, and R 13a is an alkyl group having 1 to 4 carbon atoms.

[0049] The acid generator represented by the above formula (a4) is, when n=1, R 12a is a phenyl group, a methylphenyl group, or a methoxyphenyl group, and R 13a is a methyl group, specifically, α-(methylsulfonyloxyimino)-1-phenylacetonitrile, α-(methylsulfonyloxyimino)-1-(p-methylphenyl)acetonitrile, α-(methylsulfonyloxyimino)-1-(p-methoxyphenyl)acetonitrile, [2-(propylsulfonyloxyimino)-2,3-dihydroxythiophen-3-ylidene](o-tolyl)acetonitrile, etc. When n=2, specific examples of the acid generator represented by the above formula (a4) include acid generators represented by the following formula:

[0050] [ka]

[0051] A fourth embodiment of the acid generator (A) is an onium salt having a naphthalene ring in the cation portion. The term "having a naphthalene ring" means that the structure is derived from naphthalene, and that at least two ring structures and their aromaticity are maintained. The naphthalene ring may have a substituent such as a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. The structure derived from the naphthalene ring may be a monovalent group (having one free valence) or a divalent group (having two or more free valences), but is preferably a monovalent group (however, in this case, the free valence is counted excluding the portion bonded to the above-mentioned substituent). The number of naphthalene rings is preferably 1 to 3.

[0052] The cation moiety of such an onium salt having a naphthalene ring at the cation moiety is preferably a structure represented by the following formula (a5).

[0053] [ka]

[0054] In the above formula (a5), R 14a , R 15a , R 16a At least one of R represents a group represented by the following formula (a6), 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. 14a , R 15a , R 16a one of them is a group represented by the following formula (a6), and the remaining two are each independently a linear or branched alkylene group having from 1 to 6 carbon atoms, and the ends of these may be bonded to form a ring.

[0055] [ka]

[0056] In the above formula (a6), R 17a , R 18a each independently represents a hydroxyl group, a linear or branched alkoxy group having from 1 to 6 carbon atoms, or a linear or branched alkyl group having from 1 to 6 carbon atoms; R 19a represents a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms which may have a substituent. l and m each independently represent an integer of 0 to 2, and l+m is 3 or less. 17a When there are multiple R, they may be the same or different. 18a When multiple are present, they may be the same or different.

[0057] Above R 14a , R 15a , R 16a Among these, the number of groups represented by the above formula (a6) is preferably one from the viewpoint of the stability of the compound, and the rest are linear or branched alkylene groups having 1 to 6 carbon atoms, the ends of which may be bonded to form a ring. In this case, the above two alkylene groups form a 3- to 9-membered ring including the sulfur atom. The number of atoms (including the sulfur atom) constituting the ring is preferably 5 to 6.

[0058] Furthermore, examples of the substituent that the alkylene group may have include an oxygen atom (which in this case forms a carbonyl group together with the carbon atom that constitutes the alkylene group) and a hydroxyl group.

[0059] In addition, examples of the substituent that the phenyl group may have include a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, and a linear or branched alkyl group having 1 to 6 carbon atoms.

[0060] As these cationic moieties, those represented by the following formulae (a7) and (a8) can be mentioned, and the structure represented by the following formula (a8) is particularly preferred.

[0061] [ka]

[0062] Such a cationic moiety may be either an iodonium salt or a sulfonium salt, but from the standpoint of acid generation efficiency and the like, a sulfonium salt is preferred.

[0063] Therefore, the anion moiety of an onium salt having a naphthalene ring in the cation moiety is preferably an anion capable of forming a sulfonium salt.

[0064] The anion portion of such an acid generator is a fluoroalkylsulfonate ion or an arylsulfonate ion in which some or all of the hydrogen atoms have been fluorinated.

[0065] The alkyl group in the fluoroalkylsulfonate ion may be linear, branched, or cyclic and have 1 to 20 carbon atoms, and preferably has 1 to 10 carbon atoms in view of the bulkiness of the generated acid and its diffusion distance. In particular, branched or cyclic groups are preferred because they have a short diffusion distance. In addition, preferred groups include methyl, ethyl, propyl, butyl, and octyl groups because they can be synthesized at low cost.

[0066] The aryl group in the arylsulfonate ion is an aryl group having 6 to 20 carbon atoms, and examples thereof include an alkyl group, a phenyl group which may or may not be substituted with a halogen atom, and a naphthyl group. In particular, an aryl group having 6 to 10 carbon atoms is preferred because it can be synthesized at low cost. Specific examples of preferred groups include a phenyl group, a toluenesulfonyl group, an ethylphenyl group, a naphthyl group, and a methylnaphthyl group.

[0067] In the above-mentioned fluoroalkylsulfonate ion or arylsulfonate ion, when some or all of the hydrogen atoms are fluorinated, the fluorination rate is preferably 10% or more and 100% or less, more preferably 50% or more and 100% or less, and in particular, those in which all the hydrogen atoms are replaced with fluorine atoms are preferred because they have a stronger acid strength.Specific examples of such ions include trifluoromethanesulfonate, perfluorobutanesulfonate, perfluorooctane sulfonate, and perfluorobenzenesulfonate.

[0068] Among these, preferred anion moieties include those represented by the following formula (a9).

[0069] [ka]

[0070] In the above formula (a9), R 20a are groups represented by the following formulae (a10), (a11), and (a12).

[0071] [ka]

[0072] In the above formula (a10), x represents an integer of 1 or more and 4 or less. In addition, in the above formula (a11), R 21a represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having from 1 to 6 carbon atoms, or a linear or branched alkoxy group having from 1 to 6 carbon atoms, and y represents an integer of from 1 to 3. Among these, trifluoromethanesulfonate and perfluorobutanesulfonate are preferred from the viewpoint of safety.

[0073] The anion moiety may also contain nitrogen and be represented by the following formulae (a13) and (a14).

[0074] [ka]

[0075] In the above formulas (a13) and (a14), X a represents a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, and most preferably 3 carbon atoms. 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, and the alkyl group has 1 or more and 10 or less carbon atoms, preferably 1 or more and 7 or less, and more preferably 1 or more and 3 or less carbon atoms.

[0076] X a The number of carbon atoms in the alkylene group, or Y a , Z a The smaller the number of carbon atoms in the alkyl group, the better the solubility in organic solvents, and therefore the more preferable.

[0077] Also, X a or an alkylene group of Y a , Z a In the alkyl group, the more hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The ratio of fluorine atoms in the alkylene group or alkyl group, i.e., the fluorination rate, is preferably 70% or more and 100% or less, more preferably 90% or more and 100% or less, and most preferably a perfluoroalkylene group or perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0078] Preferable onium salts having a naphthalene ring in the cation moiety include compounds represented by the following formulae (a15) and (a16).

[0079] [ka]

[0080] Further, as a fifth embodiment of the acid generator (A), there may be mentioned bissulfonyldiazomethanes such as bis(p-toluenesulfonyl)diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, and bis(2,4-dimethylphenylsulfonyl)diazomethane; nitrobenzyl derivatives such as 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, nitrobenzyl tosylate, dinitrobenzyl tosylate, nitrobenzyl sulfonate, nitrobenzyl carbonate, and dinitrobenzyl carbonate; sulfonic acid esters such as pyrogallol trimesylate, pyrogallol tritosylate, benzyl tosylate, benzyl sulfonate, N-methylsulfonyloxysuccinimide, N-trichloromethylsulfonyloxysuccinimide, N-phenylsulfonyloxymaleimide, and N-methylsulfonyloxyphthalimide; trifluoromethanesulfonic acid esters such as N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)-1,8-naphthalimide, and N-(trifluoromethylsulfonyloxy)-4-butyl-1,8-naphthalimide; onium salts such as diphenyliodonium hexafluorophosphate, (4-methoxyphenyl)phenyliodonium trifluoromethanesulfonate, bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, and (p-tert-butylphenyl)diphenylsulfonium trifluoromethanesulfonate; benzoin tosylate, benzoin tosylates such as α-methylbenzoin tosylate; and other diphenyliodonium salts, triphenylsulfonium salts, phenyldiazonium salts, and benzyl carbonate.

[0081] As the acid generator (A), a naphthalic acid derivative represented by the following formula (a21) is also preferred. [ka] (In formula (a21), R 22a is a monovalent organic group, R 23a , R 24a , R 25a , and R 26a are each independently a hydrogen atom or a monovalent organic group, R 23a and R 24a And, R 24a and R 25a and, or R 25a and R 26a may be bonded to each other to form a ring.

[0082] R 22a The organic group as the aryl group is not particularly limited as long as it does not impair the object of the present invention. The organic group may be a hydrocarbon group, or may contain a heteroatom such as O, N, S, P, or a halogen atom. The structure of the organic group may be linear, branched, cyclic, or a combination of these structures.

[0083] R 22a Suitable organic groups for the aryl group include an aliphatic hydrocarbon group having from 1 to 18 carbon atoms which may be substituted with a halogen atom and / or an alkylthio group, an aryl group having from 6 to 20 carbon atoms which may have a substituent, an aralkyl group having from 7 to 20 carbon atoms which may have a substituent, an alkylaryl group having from 7 to 20 carbon atoms which may have a substituent, a camphor-10-yl group, and a group represented by the following formula (a21a): -R 27a -(O) a -R 28a -(O) b -Y 1 -R 29a (a21a) (In formula (a21a), Y 1 R is a single bond or an alkanediyl group having 1 to 4 carbon atoms. 27a and R 28a R is an alkanediyl group having 2 to 6 carbon atoms which may be substituted with a halogen atom, or an arylene group having 6 to 20 carbon atoms which may be substituted with a halogen atom. 29ais an alkyl group having 1 to 18 carbon atoms which may be substituted with a halogen atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms which may be substituted with a halogen atom, or an aralkyl group having 7 to 20 carbon atoms which may be substituted with a halogen atom. a and b each are 0 or 1, and at least one of a and b is 1. Examples of the group include a group represented by the following formula:

[0084] R 22a When the organic group 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.

[0085] R 22a When the organic group as is an alkyl group having 1 to 18 carbon atoms substituted with an alkylthio group, the alkylthio group preferably has 1 to 18 carbon atoms. Examples of the alkylthio group having 1 to 18 carbon atoms include a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butylthio group, a sec-butylthio group, a tert-butylthio group, an isobutylthio group, an n-pentylthio group, an isopentylthio group, a tert-pentylthio group, an n-hexylthio group, an n-heptylthio group, an isoheptylthio group, a tert-heptylthio group, an n-octylthio group, an isooctylthio group, a tert-octylthio group, a 2-ethylhexylthio group, an n-nonylthio group, an n-decylthio group, an n-undecylthio group, an n-dodecylthio group, an n-tridecylthio group, an n-tetradecylthio group, an n-pentadecylthio group, an n-hexadecylthio group, an n-heptadecylthio group, and an n-octadecylthio group.

[0086] R 22a When the organic group as represented by is an aliphatic hydrocarbon group having from 1 to 18 carbon atoms which may be substituted with a halogen atom and / or an alkylthio group, the aliphatic hydrocarbon group may contain an unsaturated double bond. The structure of the aliphatic hydrocarbon group is not particularly limited, and may be linear, branched, or cyclic, or may be a combination of these structures.

[0087] R 22a When the organic group as the alkyl group is an alkenyl group, preferred examples thereof include an allyl group and a 2-methyl-2-propenyl group.

[0088] R 22a Preferred examples of the organic group as an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, an n-hexyl group, an n-hexane-2-yl group, an n-hexane-3-yl group, an n-heptyl group, an n-heptan-2-yl group, an n-heptan-3-yl group, an isoheptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a tert-octyl group, a 2-ethylhexyl group, an n-nonyl group, an isononyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, and an n-octadecyl group.

[0089] R 22a When the organic group as is an alicyclic hydrocarbon group, examples of the alicyclic hydrocarbon constituting the main skeleton of the alicyclic hydrocarbon group include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, bicyclo[2.1.1]hexane, bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[2.2.2]octane, and adamantane. As the alicyclic hydrocarbon group, a group in which one hydrogen atom has been removed from these alicyclic hydrocarbons is preferable.

[0090] R 22aPreferred examples of the organic group as an aliphatic hydrocarbon group substituted with a halogen atom include a trifluoromethyl group, a pentafluoroethyl group, a 2-chloroethyl group, a 2-bromoethyl group, a heptafluoro-n-propyl group, a 3-bromopropyl group, a nonafluoro-n-butyl group, a tridecafluoro-n-hexyl group, a heptadecafluoro-n-octyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 1,1-difluoro-n-propyl group, a 1,1,2,2-tetrafluoro-n-propyl group, a 3,3,3-trifluoro-n-propyl group, a 2,2,3,3,3-pentafluoro-n-propyl group, a 2-norbornyl-1,1-difluoroethyl group, a 2-norbornyltetrafluoroethyl group, and a 3-adamantyl-1,1,2,2-tetrafluoropropyl group.

[0091] R 22a When the organic group as the alkylthio group is an aliphatic hydrocarbon group substituted with an alkylthio group, preferred examples thereof include a 2-methylthioethyl group, a 4-methylthio-n-butyl group, and a 2-n-butylthioethyl group.

[0092] R 22a When the organic group as is an aliphatic hydrocarbon group substituted with a halogen atom and an alkylthio group, a suitable example thereof is a 3-methylthio-1,1,2,2-tetrafluoro-n-propyl group.

[0093] R 22a When the organic group as the alkyl group is an aryl group, preferred examples thereof include a phenyl group, a naphthyl group, and a biphenylyl group.

[0094] R 22a When the organic group as is an aryl group substituted with a halogen atom, preferred examples thereof include a pentafluorophenyl group, a chlorophenyl group, a dichlorophenyl group, and a trichlorophenyl group.

[0095] R 22aWhen the organic group as the alkylthio group is an aryl group substituted with an alkylthio group, preferred examples thereof include a 4-methylthiophenyl group, a 4-n-butylthiophenyl group, a 4-n-octylthiophenyl group, and a 4-n-dodecylthiophenyl group.

[0096] R 22a When the organic group as the alkyl group is an aryl group substituted with a halogen atom and an alkylthio group, preferred examples thereof include a 1,2,5,6-tetrafluoro-4-methylthiophenyl group, a 1,2,5,6-tetrafluoro-4-n-butylthiophenyl group, and a 1,2,5,6-tetrafluoro-4-n-dodecylthiophenyl group.

[0097] R 22a When the organic group as the alkyl group is an aralkyl group, preferred examples thereof include a benzyl group, a phenethyl group, a 2-phenylpropan-2-yl group, a diphenylmethyl group, and a triphenylmethyl group.

[0098] R 22a When the organic group as the alkyl group is an aralkyl group substituted with a halogen atom, preferred examples thereof include a pentafluorophenylmethyl group, a phenyldifluoromethyl group, a 2-phenyltetrafluoroethyl group, and a 2-(pentafluorophenyl)ethyl group.

[0099] R 22a When the organic group as the alkylthio group is an aralkyl group substituted with an alkylthio group, a suitable example of the organic group as the alkylthio group is a p-methylthiobenzyl group.

[0100] R 22a When the organic group as is an aralkyl group substituted with a halogen atom and an alkylthio group, a suitable example thereof is a 2-(2,3,5,6-tetrafluoro-4-methylthiophenyl)ethyl group.

[0101] R 22aPreferred examples of the organic group as an alkylaryl group include a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 3-isopropylphenyl group, a 4-isopropylphenyl group, a 4-n-butylphenyl group, a 4-isobutylphenyl group, a 4-tert-butylphenyl group, a 4-n-hexylphenyl group, a 4-cyclohexylphenyl group, a 4-n-octylphenyl group, a 4-(2-ethyl-n-hexyl)phenyl group, a 2,3-dimethylphenyl group, a 2,4-dimethylphenyl group, a 2,5-dimethylphenyl group, a 2,6-dimethylphenyl group, Examples of such groups include a 3,4-dimethylphenyl group, a 3,5-dimethylphenyl group, a 2,4-di-tert-butylphenyl group, a 2,5-di-tert-butylphenyl group, a 2,6-di-tert-butylphenyl group, a 2,4-di-tert-pentylphenyl group, a 2,5-di-tert-pentylphenyl group, a 2,5-di-tert-octylphenyl group, a 2-cyclohexylphenyl group, a 3-cyclohexylphenyl group, a 4-cyclohexylphenyl group, a 2,4,5-trimethylphenyl group, a 2,4,6-trimethylphenyl group, and a 2,4,6-triisopropylphenyl group.

[0102] The group represented by the formula (a21a) is an ether group-containing group. In formula (a21a), Y 1 Examples of the alkanediyl group having 1 to 4 carbon atoms include a methylene group, an ethane-1,2-diyl group, an ethane-1,1-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a butane-1,3-diyl group, a butane-2,3-diyl group, and a butane-1,2-diyl group. In formula (a21a), R 27a or R 28aExamples of the alkanediyl group having 2 to 6 carbon atoms include an ethane-1,2-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a butane-1,3-diyl group, a butane-2,3-diyl group, a butane-1,2-diyl group, a pentane-1,5-diyl group, a pentane-1,3-diyl group, a pentane-1,4-diyl group, a pentane-2,3-diyl group, a hexane-1,6-diyl group, a hexane-1,2-diyl group, a hexane-1,3-diyl group, a hexane-1,4-diyl group, a hexane-2,5-diyl group, a hexane-2,4-diyl group, and a hexane-3,4-diyl group.

[0103] In formula (a21a), R 27a or R 28a is an alkanediyl group having 2 to 6 carbon atoms substituted with a halogen atom, examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. Examples of the alkanediyl group substituted with a halogen atom include a tetrafluoroethane-1,2-diyl group, a 1,1-difluoroethane-1,2-diyl group, a 1-fluoroethane-1,2-diyl group, a 1,2-difluoroethane-1,2-diyl group, a hexafluoropropane-1,3-diyl group, a 1,1,2,2-tetrafluoropropane-1,3-diyl group, and a 1,1,2,2-tetrafluoropentane-1,5-diyl group.

[0104] In formula (a21a), R 27a or R 28aExamples of the aryl group include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a 2,5-dimethyl-1,4-phenylene group, a biphenyl-4,4'-diyl group, a diphenylmethane-4,4'-diyl group, a 2,2-diphenylpropane-4,4'-diyl group, a naphthalene-1,2-diyl group, a naphthalene-1,3-diyl group, a naphthalene-1,4-diyl group, a naphthalene-1,5-diyl group, a naphthalene-1,6-diyl group, a naphthalene-1,7-diyl group, a naphthalene-1,8-diyl group, a naphthalene-2,3-diyl group, a naphthalene-2,6-diyl group, and a naphthalene-2,7-diyl group.

[0105] In formula (a21a), R 27a or R 28a is an arylene group substituted with a halogen atom, the halogen atom includes a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. An example of an arylene group substituted with a halogen atom includes a 2,3,5,6-tetrafluoro-1,4-phenylene group.

[0106] In formula (a21a), R 29a Examples of the alkyl group having 1 to 18 carbon atoms and optionally having a branch, as represented by the formula (I), include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, an n-hexyl group, an n-hexane-2-yl group, an n-hexane-3-yl group, an n-heptyl group, an n-heptan-2-yl group, an n-heptan-3-yl group, an isoheptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a tert-octyl group, a 2-ethylhexyl group, an n-nonyl group, an isononyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, and an n-octadecyl group.

[0107] In formula (a21a), R 29ais an alkyl group having 1 to 18 carbon atoms substituted with a halogen atom, examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom. Examples of the alkyl group substituted with a halogen atom include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoro-n-propyl group, a nonafluoro-n-butyl group, a tridecafluoro-n-hexyl group, a heptadecafluoro-n-octyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 1,1-difluoro-n-propyl group, a 1,1,2,2-tetrafluoro-n-propyl group, a 3,3,3-trifluoro-n-propyl group, a 2,2,3,3,3-pentafluoro-n-propyl group, and a 1,1,2,2-tetrafluorotetradecyl group.

[0108] In formula (a21a), R 29a 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 in which one hydrogen atom has been removed from these alicyclic hydrocarbons is preferable.

[0109] In formula (a21a), R 29a is an aryl group, a halogenated aryl group, an aralkyl group, or a halogenated aralkyl group, preferred examples of these groups are R 22a The same applies when these groups are used.

[0110] Among the groups represented by formula (a21a), a suitable group is R 27a In the above-mentioned formula (1), the carbon atom bonded to the sulfur atom is substituted with a fluorine atom. The number of carbon atoms in such a suitable group is preferably 2 or more and 18 or less.

[0111] R 22aAs R, a perfluoroalkyl group having 1 to 8 carbon atoms is preferable. In addition, a camphor-10-yl group is also preferable because it is easy to form a high-definition resist pattern. 22a As preferred.

[0112] In formula (a21), R 23a ~R 26a is a hydrogen atom or a monovalent organic group. 23a and R 24a And, R 24a and R 25a and, or R 25a and R 26a may be bonded to each other to form a ring. For example, R 24a and R 25a may be bonded to the naphthalene ring to form a five-membered ring, thereby forming an acenaphthene skeleton.

[0113] The monovalent organic group is preferably an alicyclic hydrocarbon group, a heterocyclic group (heterocyclyl group), or an alkyl group or alkoxy group having 4 to 18 carbon atoms which may be substituted with a halogen atom and which may have a branched structure; a heterocyclyloxy group; an alicyclic hydrocarbon group, a heterocyclic group (heterocyclyl group), or an alkylthio group having 4 to 18 carbon atoms which may be substituted with a halogen atom and which may have a branched structure; or a heterocyclylthio group. Also preferred is a group in which a methylene group at any position not adjacent to the oxygen atom of the alkoxy group is substituted with -CO-. Also preferred is an alkoxy group interrupted by an -O-CO- bond or an -O-CO-NH- bond, where the left end of the -O-CO- bond or the -O-CO-NH- bond is closer to the naphthalic acid mother nucleus in the alkoxy group. Furthermore, an alicyclic hydrocarbon group, a heterocyclic group, or an alkylthio group having 4 to 18 carbon atoms which may be substituted with a halogen atom and which may have a branched structure is also included in R. 23a ~R 26a As preferred. Also preferred is an alkylthio group in which a methylene group at any position not adjacent to the sulfur atom is substituted with -CO-. Also preferred is an alkylthio group interrupted by an -O-CO- bond or an -O-CO-NH- bond, where the left end of the -O-CO- bond or the -O-CO-NH- bond is closer to the naphthalic acid mother nucleus in the alkylthio group.

[0114] R 23a ~R 26a As for R 23a is an organic group, and R 24a ~R 26a is a hydrogen atom or R 24a is an organic group, and R 23a , R 25a , and R 26a is preferably a hydrogen atom. 23a ~R 26a may all be hydrogen atoms.

[0115] R 23a ~R 26a Examples of the alkyl group that is an unsubstituted alkyl group include an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, an n-hexyl group, an n-heptyl group, an isoheptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a tert-octyl group, a 2-ethylhexyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, and an n-octadecyl group.

[0116] R 23a ~R 26aExamples of the alkoxy group represented by the formula (I) include an unsubstituted alkoxy group, such as an n-butyloxy group, a sec-butyloxy group, a tert-butyloxy group, an isobutyloxy group, an n-pentyloxy group, an isopentyloxy group, a tert-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an isoheptyloxy group, a tert-heptyloxy group, an n-octyloxy group, an isooctyloxy group, a tert-octyloxy group, a 2-ethylhexyl group, an n-nonyloxy group, an n-decyloxy group, an n-undecyloxy group, an n-dodecyloxy group, an n-tridecyloxy group, an n-tetradecyloxy group, an n-pentadecyloxy group, an n-hexadecyloxy group, an n-heptadecyloxy group, and an n-octadecyloxy group.

[0117] R 23a ~R 26a Examples of the alkylthio group that is an unsubstituted alkylthio group include an n-butylthio group, a sec-butylthio group, a tert-butylthio group, an isobutylthio group, an n-pentylthio group, an isopentylthio group, a tert-pentylthio group, an n-hexylthio group, an n-heptylthio group, an isoheptylthio group, a tert-heptylthio group, an n-octylthio group, an isooctylthio group, a tert-octylthio group, a 2-ethylhexylthio group, an n-nonylthio group, an n-decylthio group, an n-undecylthio group, an n-dodecylthio group, an n-tridecylthio group, an n-tetradecylthio group, an n-pentadecylthio group, an n-hexadecylthio group, an n-heptadecylthio group, and an n-octadecylthio group.

[0118] R 23a ~R 26ais an alkyl group, an alkoxy group, or an alkylthio group substituted with an alicyclic hydrocarbon group, examples of the alicyclic hydrocarbon constituting the main skeleton of the alicyclic hydrocarbon group include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, bicyclo[2.1.1]hexane, bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[2.2.2]octane, and adamantane. As the alicyclic hydrocarbon group, a group in which one hydrogen atom has been removed from these alicyclic hydrocarbons is preferable.

[0119] R 23a ~R 26a is an alkyl group, an alkoxy group, or an alkylthio group substituted with a heterocyclic group, or R 23a ~R 26a When is a heterocyclyloxy group, examples of the heterocycle constituting the heterocyclic group or the main skeleton of the heterocyclyloxy group include pyrrole, thiophene, furan, pyran, thiopyran, imidazole, pyrazole, thiazole, isothiazole, oxazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, pyrrolidine, pyrazolidine, imidazolidine, isoxazolidine, isothiazolidine, piperidine, piperazine, morpholine, thiomorpholine, chroman, thiochroman, isochroman, isothiochroman, indoline, isoindoline, and pyrimidine. Examples of the heterocyclic ring include lindine, indolizine, indole, indazole, purine, quinolizine, isoquinoline, quinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, perimidine, phenanthroline, carbazole, carboline, phenazine, anthridine, thiadiazole, oxadiazole, triazine, triazole, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzothiadiazole, benzofuroxan, naphthoimidazole, benzotriazole, and tetraazaindene. Among these heterocyclic rings, saturated heterocyclic rings in which a ring having a conjugated bond is hydrogenated are also preferred. As the heterocyclic group substituting an alkyl group, an alkoxy group or an alkylthio group, or the heterocyclic group contained in a heterocyclyloxy group, a group in which one hydrogen atom has been removed from the above heterocycle is preferred.

[0120] R 23a ~R 26a is an alkoxy group containing an alicyclic hydrocarbon group, examples of which include a cyclopentyloxy group, a methylcyclopentyloxy group, a cyclohexyloxy group, a fluorocyclohexyloxy group, a chlorocyclohexyloxy group, a cyclohexylmethyloxy group, a methylcyclohexyloxy group, a norbornyloxy group, an ethylcyclohexyloxy group, a cyclohexylethyloxy group, a dimethylcyclohexyloxy group, a methylcyclohexylmethyloxy group, a norbornylmethyloxy group, a trimethylcyclohexyloxy group, Examples of such groups include a cyclohexylbutyloxy group, an adamantyloxy group, a menthyloxy group, an n-butylcyclohexyloxy group, a tert-butylcyclohexyloxy group, a bornyloxy group, an isobornyloxy group, a decahydronaphthyloxy group, a dicyclopentadienoxy group, a 1-cyclohexylpentyloxy group, a methyladamantyloxy group, an adamantylmethyloxy group, a 4-pentylcyclohexyloxy group, a cyclohexylcyclohexyloxy group, an adamantylethyloxy group, and a dimethyladamantyloxy group.

[0121] R 23a ~R 26a When is a heterocyclyloxy group, examples thereof include a tetrahydrofuranyloxy group, a furfuryloxy group, a tetrahydrofurfuryloxy group, a tetrahydropyranyloxy group, a butyrolactonyloxy group, and an indolyloxy group.

[0122] R 23a ~R 26a Examples of the alkylthio group containing an alicyclic hydrocarbon group include a cyclopentylthio group, a cyclohexylthio group, a cyclohexylmethylthio group, a norbornylthio group, and an isonorbornylthio group.

[0123] R 23a ~R 26a When is a heterocyclylthio group, examples thereof include a furfurylthio group and a tetrahydrofuranylthio group.

[0124] R 23a ~R 26a However, examples of the alkoxy group in which a methylene group at any position not adjacent to the oxygen atom of the alkoxy group is substituted with -CO- include a 2-ketobutyl-1-oxy group, a 2-ketopentyl-1-oxy group, a 2-ketohexyl-1-oxy group, a 2-ketoheptyl-1-oxy group, a 2-ketooctyl-1-oxy group, a 3-ketobutyl-1-oxy group, a 4-ketopentyl-1-oxy group, a 5-ketohexyl-1-oxy group, a 6-ketoheptyl-1-oxy group, a 7-ketooctyl-1-oxy group, a 3-methyl-2-ketopentan-4-oxy group, a 2-ketopentan-4-oxy group, a 2-methyl-2-ketopentan-4-oxy group, a 3-ketoheptan-5-oxy group, and a 2-adamantanone-5-oxy group.

[0125] R 23a ~R 26a However, examples of the alkylthio group in which a methylene group at any position not adjacent to the sulfur atom is substituted with -CO- include a 2-ketobutyl-1-thio group, a 2-ketopentyl-1-thio group, a 2-ketohexyl-1-thio group, a 2-ketoheptyl-1-thio group, a 2-ketooctyl-1-thio group, a 3-ketobutyl-1-thio group, a 4-ketopentyl-1-thio group, a 5-ketohexyl-1-thio group, a 6-ketoheptyl-1-thio group, a 7-ketooctyl-1-thio group, a 3-methyl-2-ketopentane-4-thio group, a 2-ketopentane-4-thio group, a 2-methyl-2-ketopentane-4-thio group, and a 3-ketoheptane-5-thio group.

[0126] Specific examples of the compound represented by formula (a21) include the following compounds.

[0127] [ka]

[0128]

change

[0129]

change

[0130]

change

[0131]

change

[0132]

change

[0133]

change

[0134]

change

[0135]

change

[0136]

change

[0137] The acid generator (A) may be used alone or in combination of two or more. The content of the acid generator (A) is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 6% by mass or less, and particularly preferably 0.5% by mass or more and 3% by mass or less, based on the total solid content of the photosensitive composition. By setting the amount of the acid generator (A) used within the above range, it is easy to prepare a photosensitive composition that has good sensitivity, is a homogeneous solution, and has excellent storage stability.

[0138] <Resin (B)> The photosensitive composition contains, as an essential component, an acrylic resin (B3) as the resin (B) whose solubility in alkali increases under the action of an acid. The acrylic resin (B3) contains a structural unit represented by formula (B3-1). The photosensitive composition may contain, together with the acrylic resin (B3), any resin other than the acrylic resin (B3) whose solubility in alkali increases under the action of an acid, provided that the ratio of the mass of the acrylic resin (B3) to the mass of the resin (B) is preferably 50 mass% or more, more preferably 70 mass% or more, even more preferably 90 mass% or more, and particularly preferably 100 mass% or more. Examples of any resin other than the acrylic resin (B3) whose solubility in alkali increases when exposed to an acid include novolak resin (B1) whose solubility in alkali increases when exposed to an acid, polyhydroxystyrene resin (B2) whose solubility in alkali increases when exposed to an acid, and acrylic resins other than the acrylic resin (B3) whose solubility in alkali increases when exposed to an acid. Each resin will be specifically described below.

[0139] [Novolac resin (B1)] As the novolak resin (B1), a resin containing a structural unit represented by the following formula (b1) can be used.

[0140] [ka]

[0141] In the above formula (b1), R 1b represents an acid dissociable dissolution inhibiting group, R 2b , R 3b each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0142] Above R 1b The acid dissociable, dissolution inhibiting group represented by the formula (b2) or (b3) below is preferably a linear, branched, or cyclic alkyl group having from 1 to 6 carbon atoms, a vinyloxyethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, or a trialkylsilyl group.

[0143] [ka]

[0144] In the above formulas (b2) and (b3), R 4b , R 5b each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms; R 6b represents a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; R 7b represents a linear, branched, or cyclic alkyl group having from 1 to 6 carbon atoms, and o represents 0 or 1.

[0145] Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. Examples of the cyclic alkyl group include a cyclopentyl group, a cyclohexyl group, etc.

[0146] Here, specific examples of the acid dissociable dissolution inhibiting group represented by the above formula (b2) include a methoxyethyl group, an ethoxyethyl group, an n-propoxyethyl group, an isopropoxyethyl group, an n-butoxyethyl group, an isobutoxyethyl group, a tert-butoxyethyl group, a cyclohexyloxyethyl group, a methoxypropyl group, an ethoxypropyl group, a 1-methoxy-1-methyl-ethyl group, and a 1-ethoxy-1-methylethyl group. Specific examples of the acid dissociable dissolution inhibiting group represented by the above formula (b3) include a tert-butoxycarbonyl group, a tert-butoxycarbonylmethyl group, and the like. Examples of the trialkylsilyl group include a trimethylsilyl group, a tri-tert-butyldimethylsilyl group, and the like, in which the number of carbon atoms in each alkyl group is 1 to 6.

[0147] [Polyhydroxystyrene resin (B2)] As the polyhydroxystyrene resin (B2), a resin containing a structural unit represented by the following formula (b4) can be used.

[0148] [ka]

[0149] In the above formula (b4), R 8b represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 9b represents an acid dissociable, dissolution inhibiting group.

[0150] The alkyl group having from 1 to 6 carbon atoms is, for example, a straight-chain, branched, or cyclic alkyl group having from 1 to 6 carbon atoms. Examples of the straight-chain or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group, and examples of the cyclic alkyl group include a cyclopentyl group, and a cyclohexyl group.

[0151] Above R 9bAs the acid dissociable, dissolution inhibiting group represented by the formula (b2) or (b3) above, the same acid dissociable, dissolution inhibiting groups as those exemplified above can be used.

[0152] Furthermore, the polyhydroxystyrene resin (B2) may contain other polymerizable compounds as constituent units for the purpose of appropriately controlling the physical and chemical properties. Examples of such polymerizable compounds include known radically polymerizable compounds and anionically polymerizable compounds. Examples of such polymerizable compounds include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxy group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; phenyl (meth)acrylate, phenyl (meth)acrylate, and phenyl (meth)acrylate. Examples of suitable polymerizable compounds include (meth)acrylic acid aryl esters such as diethyl maleate and dibutyl fumarate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; vinyl group-containing aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene and α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; and amide bond-containing polymerizable compounds such as acrylamide and methacrylamide.

[0153] [Acrylic resin (B3)] The acrylic resin (B3) serving as the resin (B) whose solubility in alkali increases under the action of an acid contains a structural unit represented by the following formula (B3-1). [ka] (In formula (B3-1), R b01 is -O-, -S-, -CO-O-, -CO-NH-, or -SO2-; R b02 and R b03 are each independently a hydrogen atom or an organic group; R b02 and R b03 At least one of -CO-OR b04 R b04 is a hydrogen atom or an organic group, and x1 and x2 are each independently 1 or 2.

[0154] In this specification, the term "acrylic resin" refers to a resin in which the ratio of the total of the structural units represented by formula (B3-1) and the structural units derived from a monomer having a (meth)acryloyloxy group to all the structural units constituting the resin is 50 mol % or more, preferably 70 mol % or more, and more preferably 90 mol % or more. In addition, in this specification, "(meth)acrylic" means both "acrylic" and "methacrylic". "(meth)acrylate" means both "acrylate" and "methacrylate". "(meth)acryloyloxy" means both "acryloyloxy" and "methacryloyloxy".

[0155] In formula (B3-1), R b01 is -O-, -S-, -CO-O-, -CO-NH-, or -SO2-. b01 is preferably —O—. In other words, the formula (B3-1) is preferably a structure in which a cyclic ether is formed in the main chain.

[0156] In formula (B3-1), R b02 and R b03 are each independently a hydrogen atom or an organic group; R b02 and Rb03 At least one of -CO-OR b04 It is a group represented by the following formula: R b02 and R b03 The organic group is -CO-OR b04 Examples of the group include a group represented by the following formula:

[0157] R b04 is a hydrogen atom or an organic group. R b04 The organic group may be a hydrocarbon group having from 1 to 20 carbon atoms. The hydrocarbon group having from 1 to 20 carbon atoms may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Examples of the aliphatic hydrocarbon group include linear or branched alkyl groups, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group. Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.

[0158] In the formula (B3-1), the sum of x1 and x2 is preferably 2 or 3 from the viewpoint of a stable cyclic structure. For example, in the formula (B3-1), both x1 and x2 are 1, and R b02 and R b03 It is preferable that one of them is a hydrogen atom.

[0159] The constitutional unit represented by formula (B3-1) can be introduced into the acrylic resin (B3), for example, by using the following compound, which is a monomer corresponding to formula (B3-1), as a copolymerization component. [ka]

[0160] Specific examples of the structural unit represented by formula (B3-1) include the structural units shown below. [ka]

[0161] If the solids concentration is high, the storage stability is poor, and for example, the viscosity of the photosensitive composition is likely to change over time. However, by using an acrylic resin (B3) containing a structural unit represented by formula (B3-1) as the resin (B) and setting the solids concentration in the range of 25 mass % or more and 70 mass % or less, a photosensitive composition having excellent storage stability can be realized despite its high solids concentration. For example, when the viscosity of the photosensitive composition measured at 25°C using an E-type viscometer is V1, and the photosensitive composition is allowed to stand at 40°C for two weeks and then the viscosity of the photosensitive composition after standing is measured at 25°C using an E-type viscometer is V2, it is possible to make V2 / V1 less than 1.1. Since the photosensitive composition has a high solid concentration, it is easy to form a thick photosensitive layer (for example, 70 μm or more), and therefore the photosensitive composition can be preferably used for forming a plated object, for example.

[0162] In addition, the photosensitive layer formed using the above-mentioned photosensitive composition is suppressed from repelling the developer after exposure, so that, for example, the developer can be brought into contact with the entire photosensitive layer, and a resist pattern having a desired shape according to a mask or the like can be formed over the entire area where the photosensitive layer is provided.

[0163] In addition, the photosensitive layer formed using the above-mentioned photosensitive composition is suppressed from swelling during development after exposure, and therefore, for example, the resist pattern obtained is suppressed from wrinkling, dissolution of unexposed areas, and lifting and distortion caused by swelling.

[0164] In addition, the photosensitive layer formed using the above-mentioned photosensitive composition is less susceptible to cracking, i.e., has excellent crack resistance, and therefore, for example, when the resulting resist pattern is used as a mold for forming a plated object, it is easy to form a plated object of a desired shape.

[0165] The amount of the structural unit represented by formula (B3-1) in the acrylic resin (B3) is not particularly limited, but the ratio of the mass of the structural unit represented by formula (B3-1) to the mass of the acrylic resin (B3) is preferably 5 mass% or more and 50 mass% or less, more preferably 10 mass% or more and 40 mass% or less, and even more preferably 10 mass% or more and 30 mass% or less.

[0166] The acrylic resin (B3) may contain, for example, a structural unit (b-3) derived from an acrylic acid ester containing an -SO2- containing cyclic group or a lactone-containing cyclic group. In this case, when forming a resist pattern, it is easy to form a resist pattern having a preferable cross-sectional shape. However, if the photosensitive composition has an -SO2- containing cyclic group or a lactone-containing cyclic group, the storage stability of the photosensitive composition is deteriorated, so it is preferable that the photosensitive composition does not contain, or has a small content of, an -SO2- containing cyclic group and a lactone-containing cyclic group.

[0167] (-SO2-containing cyclic group) Here, the term "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2- in its ring structure, specifically, a cyclic group in which the sulfur atom (S) in -SO2- forms a part of the ring structure of the cyclic group. The ring containing -SO2- in the ring structure is counted as the first ring, and if there is only this ring, it is called a monocyclic group, and if there is another ring structure, it is called a polycyclic group regardless of the structure. The -SO2-containing cyclic group may be monocyclic or polycyclic.

[0168] The -SO2- containing cyclic group is preferably a cyclic group containing -O-SO2- in its ring skeleton, that is, a cyclic group containing a sultone ring in which -OS- in -O-SO2- forms a part of the ring skeleton.

[0169] The number of carbon atoms in the -SO2- containing cyclic group is preferably from 3 to 30, more preferably from 4 to 20, further preferably from 4 to 15, and particularly preferably from 4 to 12. The number of carbon atoms is the number of carbon atoms constituting the ring skeleton and does not include the number of carbon atoms in the substituent.

[0170] The -SO2- containing cyclic group may be an -SO2- containing aliphatic cyclic group or an -SO2- containing aromatic cyclic group, preferably an -SO2- containing aliphatic cyclic group.

[0171] Examples of the -SO2- containing aliphatic cyclic group include a group in which at least one hydrogen atom has been removed from an aliphatic hydrocarbon ring in which a portion of the carbon atoms constituting the ring skeleton is substituted with -SO2- or -O-SO2-. More specifically, examples thereof include a group in which at least one hydrogen atom has been removed from an aliphatic hydrocarbon ring in which -CH2- constituting the ring skeleton is substituted with -SO2-, a group in which at least one hydrogen atom has been removed from an aliphatic hydrocarbon ring in which -CH2-CH2- constituting the ring skeleton is substituted with -O-SO2-, and the like.

[0172] The number of carbon atoms in the alicyclic hydrocarbon ring is preferably 3 to 20, more preferably 3 to 12. The alicyclic hydrocarbon ring may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon ring is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms, and specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0173] The -SO2- containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (=O), -COOR", -OC(=O)R", a hydroxyalkyl group, and a cyano group.

[0174] The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and n-hexyl groups. Among these, methyl and ethyl groups are preferred, and methyl groups are particularly preferred.

[0175] The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specific examples include groups in which the alkyl groups listed above as the alkyl groups as the substituent are bonded to an oxygen atom (-O-).

[0176] Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred.

[0177] Examples of the halogenated alkyl group for the substituent include the above-mentioned alkyl groups in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms.

[0178] Examples of the halogenated alkyl group as the substituent include the alkyl groups listed above as the alkyl groups as the substituent, in which some or all of the hydrogen atoms are substituted with the halogen atoms listed above. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0179] Each of the R″ in the above-mentioned —COOR″ and —OC(═O)R″ is a hydrogen atom or a linear, branched, or cyclic alkyl group having 1 to 15 carbon atoms.

[0180] When R″ is a linear or branched alkyl group, the linear alkyl group preferably has 1 or more and 10 or less, more preferably 1 or more and 5 or less, and particularly preferably 1 or 2 carbon atoms.

[0181] When R" is a cyclic alkyl group, the cyclic alkyl group preferably has 3 or more and 15 or less carbon atoms, more preferably 4 or more and 12 or less, and particularly preferably 5 or more and 10 or less. Specific examples include monocycloalkanes which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, and groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkanes such as cyclopentane and cyclohexane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0182] The hydroxyalkyl group as the substituent is preferably a hydroxyalkyl group having from 1 to 6 carbon atoms. Specific examples thereof include groups in which at least one hydrogen atom of the alkyl groups listed above as the alkyl group as the substituent is substituted with a hydroxyl group.

[0183] More specific examples of the -SO2- containing cyclic group include groups represented by the following formulas (3-1) to (3-4). [ka] (In the formula, 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; z is an integer of 0 to 2; R 10b is an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group, and R" is a hydrogen atom or an alkyl group.

[0184] In the above formulas (3-1) to (3-4), 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. The alkylene group having 1 to 5 carbon atoms in A' is preferably a linear or branched alkylene group, and examples of such groups include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.

[0185] When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, etc. A' is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0186] z may be any of 0, 1, and 2, and is most preferably 0. When z is 2, a plurality of R 10b may be the same or different.

[0187] R 10b Examples of the alkyl group, alkoxy group, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the above formula include the same as those described above for the alkyl group, alkoxy group, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group listed as the substituent that the -SO- containing cyclic group may have.

[0188] Specific examples of the cyclic groups represented by the above formulas (3-1) to (3-4) are shown below, in which "Ac" represents an acetyl group.

[0189] [ka]

[0190] [ka]

[0191] As the -SO2- containing cyclic group, among the above, the group represented by the above formula (3-1) is preferable, at least one selected from the group consisting of the groups represented by any one of the above chemical formulas (3-1-1), (3-1-18), (3-3-1), and (3-4-1) is more preferable, and the group represented by the above chemical formula (3-1-1) is most preferable.

[0192] (Lactone-containing cyclic group) A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is further a ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

[0193] The lactone cyclic group in the structural unit (b-3) is not particularly limited and any one can be used.Specifically, lactone-containing monocyclic groups include groups in which one hydrogen atom is removed from 4- to 6-membered ring lactones, such as groups in which one hydrogen atom is removed from β-propionolactone, groups in which one hydrogen atom is removed from γ-butyrolactone, and groups in which one hydrogen atom is removed from δ-valerolactone.Furthermore, lactone-containing polycyclic groups include groups in which one hydrogen atom is removed from bicycloalkanes, tricycloalkanes, and tetracycloalkanes having a lactone ring.

[0194] As the structural unit (b-3), there are no particular limitations on the structure of the other portions as long as it has an -SO2- containing cyclic group or a lactone-containing cyclic group, but at least one structural unit selected from the group consisting of structural units (b-3-S) derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent and which contain an -SO2- containing cyclic group, and structural units (b-3-L) derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent and which contain a lactone-containing cyclic group are preferred.

[0195] [Structural unit (b-3-S)] More specific examples of the structural unit (b-3-S) include structural units represented by the following formula (b-S1).

[0196] [ka] (In the formula, R is a hydrogen atom, an alkyl group having from 1 to 5 carbon atoms, or a halogenated alkyl group having from 1 to 5 carbon atoms; R 11b is a -SO2- containing cyclic group, R 12b is a single bond or a divalent linking group.

[0197] In formula (b-S1), R is the same as defined above. R 11b is the same as the -SO2- containing cyclic group mentioned above. R 12b may be either a single bond or a divalent linking group.

[0198] R 12b The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0199] Optionally substituted divalent hydrocarbon group The hydrocarbon group as the divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated. Generally, a saturated hydrocarbon group is preferred. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, and the like.

[0200] The linear or branched aliphatic hydrocarbon group preferably has 1 or more and 10 or less, more preferably 1 or more and 8 or less, and even more preferably 1 or more and 5 or less, carbon atoms.

[0201] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, specifically, a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. can be mentioned.

[0202] The branched aliphatic hydrocarbon group is preferably a branched alkylene group. Specific examples thereof include alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2-, and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2-, and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0203] The linear or branched aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and an oxo group (=O).

[0204] Examples of the aliphatic hydrocarbon group containing a ring in the above structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above.

[0205] The cyclic aliphatic hydrocarbon group preferably has 3 or more and 20 or less, and more preferably has 3 or more and 12 or less, carbon atoms.

[0206] The cyclic aliphatic hydrocarbon group may be polycyclic or monocyclic. The monocyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The number of carbon atoms in the monocycloalkane is preferably 3 or more and 6 or less. Specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane. The number of carbon atoms in the polycycloalkane is preferably 7 or more and 12 or less. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0207] The cyclic aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (=O).

[0208] The alkyl group as the above-mentioned substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

[0209] The alkoxy group as the above-mentioned substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and particularly preferably a methoxy group or an ethoxy group.

[0210] Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred.

[0211] Examples of the halogenated alkyl group as the above-mentioned substituent include the above-mentioned alkyl groups in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms.

[0212] In the cyclic aliphatic hydrocarbon group, a part of the carbon atoms constituting the ring structure may be substituted with -O- or -S-. As the substituent containing a hetero atom, -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O- are preferred.

[0213] The aromatic hydrocarbon group as a divalent hydrocarbon group is a divalent hydrocarbon group having at least one aromatic ring, and may have a substituent. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms of the substituent.

[0214] Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom; and the like. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

[0215] Specific examples of the aromatic hydrocarbon group as a divalent hydrocarbon group include a group in which two hydrogen atoms have been removed from the above-mentioned aromatic hydrocarbon ring or aromatic heterocycle (arylene group, or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the above-mentioned aromatic hydrocarbon ring or aromatic heterocycle (aryl group, or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group); and the like.

[0216] The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 or more and 4 or less, more preferably 1 or more and 2 or less, and particularly preferably 1.

[0217] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (=O).

[0218] The alkyl group as the above-mentioned substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a tert-butyl group.

[0219] The alkoxy group as the above-mentioned substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and more preferably a methoxy group or an ethoxy group.

[0220] Examples of the halogen atom as the above-mentioned substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred.

[0221] Examples of the halogenated alkyl group as the above-mentioned substituent include the above-mentioned alkyl groups in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms.

[0222] Divalent linking group containing a heteroatom The heteroatom in the divalent linking group containing a heteroatom is an atom other than a carbon atom or a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

[0223] Specific examples of the divalent linking group containing a heteroatom include non-hydrocarbon linking groups such as -O-, -C(=O)-, -C(=O)-O-, -OC(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-, -NH-, -NH-C(=O)-, -NH-C(=NH)-, =N-, and the like, as well as combinations of at least one of these non-hydrocarbon linking groups with a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include the same as the divalent hydrocarbon group that may have the above-mentioned substituent, and linear or branched aliphatic hydrocarbon groups are preferred.

[0224] Among the above, -NH- in -C(=O)-NH-, -NH-, and H in -NH-C(=NH)- may each be substituted with a substituent such as an alkyl group, an acyl group, etc. The number of carbon atoms in the substituent is preferably 1 to 10, more preferably 1 to 8, and particularly preferably 1 to 5.

[0225] R 12bAs the divalent linking group in the above formula, a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent linking group containing a hetero atom is particularly preferred.

[0226] R 12b When the divalent linking group in is a linear or branched alkylene group, the number of carbon atoms in the alkylene group is preferably from 1 to 10, more preferably from 1 to 6, particularly preferably from 1 to 4, and most preferably from 1 to 3. Specific examples thereof include the same linear alkylene groups and branched alkylene groups as those exemplified as the linear or branched aliphatic hydrocarbon groups in the explanation of the "divalent hydrocarbon group which may have a substituent" described above as the divalent linking group.

[0227] R 12b When the divalent linking group in is a cyclic aliphatic hydrocarbon group, examples of the cyclic aliphatic hydrocarbon group include the same as the cyclic aliphatic hydrocarbon groups exemplified as the "aliphatic hydrocarbon group having a ring in its structure" in the explanation of the "divalent hydrocarbon group which may have a substituent" as the above-mentioned divalent linking group.

[0228] As the cyclic aliphatic hydrocarbon group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferred.

[0229] R 12b When the divalent linking group in the formula (I) is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and a group represented by the general formula -Y 1 -OY 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 A group represented by —OC(═O)—Y—,1 , and Y 2 each independently represents 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.

[0230] R 12b When the divalent linking group in is -NH-, the hydrogen atom in -NH- may be substituted with a substituent such as an alkyl group, acyl, etc. The number of carbon atoms in the substituent (alkyl group, acyl group, etc.) is preferably 1 to 10, more preferably 1 to 8, and particularly preferably 1 to 5.

[0231] Formula-Y 1 -OY 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 -OC(=O)-Y 2 -Medium, Y 1 , and Y 2 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same ones as the "divalent hydrocarbon group which may have a substituent" listed above in the description of the divalent linking group.

[0232] Y 1 As the alkyl group, a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is even more preferable, and a methylene group and an ethylene group are particularly preferable.

[0233] Y 2 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[0234] Formula − [Y 1 -C(=O)-O]m’ -Y 2 In the group represented by -, m' is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 1 -C(=O)-O] m’ -Y 2 The group represented by the formula -Y 1 -C(=O)-OY 2 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ In the formula, a' is an integer of 1 or more and 10 or less, preferably an integer of 1 or more and 8 or less, more preferably an integer of 1 or more and 5 or less, even more preferably 1 or 2, and most preferably 1. b' is an integer of 1 or more and 10 or less, preferably an integer of 1 or more and 8 or less, more preferably an integer of 1 or more and 5 or less, even more preferably 1 or 2, and most preferably 1.

[0235] R 12b As for the divalent linking group in the formula (I), the divalent linking group containing a hetero atom is preferably an organic group consisting of a combination of at least one non-hydrocarbon group and a divalent hydrocarbon group. Among them, a linear group having an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, is preferred, and the above-mentioned formula -Y 1 -OY 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 -OC(=O)-Y 2 A group represented by the above formula -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 -OC(=O)-Y 2 A group represented by - is particularly preferred.

[0236] R 12b The divalent linking group in is preferably an alkylene group or one containing an ester bond (-C(=O)-O-).

[0237] The alkylene group is preferably a linear or branched alkylene group. Suitable examples of the linear aliphatic hydrocarbon group include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. Suitable examples of the branched alkylene group include alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-.

[0238] As the divalent linking group containing an ester bond, particularly, a group represented by the formula: -R 13b -C(=O)-O-[wherein, R 13b is a divalent linking group. In other words, the structural unit (b-3-S) is preferably a structural unit represented by the following formula (b-S1-1).

[0239] [ka] (Wherein, R and R 11b are the same as above, and R 13b is a divalent linking group.

[0240] R 13b is not particularly limited, and examples thereof include the above-mentioned R 12b The divalent linking group may be the same as the divalent linking group in the above formula. R 13bThe divalent linking group is preferably a linear or branched alkylene group, an aliphatic hydrocarbon group containing a ring in the structure, or a divalent linking group containing a heteroatom, and is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom as a heteroatom.

[0241] As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable. As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and -CH(CH3)-, -C(CH3)2-, or -C(CH3)2CH2- is particularly preferable.

[0242] The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and the above-mentioned -Y 1 -OY 2 -, -[Y 1 -C(=O)-O] m’ -Y 2 - or -Y 1 -OC(=O)-Y 2 - is more preferable. 1 , and Y 2 are each independently a divalent hydrocarbon group which may have a substituent, and m' is an integer of 0 to 3. 1 -OC(=O)-Y 2 - is preferred, -(CH2) c -OC(=O)-(CH2) d A group represented by the formula - is particularly preferred. c is an integer of 1 or more and 5 or less, and preferably 1 or 2. d is an integer of 1 or more and 5 or less, and preferably 1 or 2.

[0243] As the structural unit (b-3-S), a structural unit represented by the following formula (b-S1-11) or (b-S1-12) is particularly preferable, and a structural unit represented by formula (b-S1-12) is more preferable.

[0244] [ka] (In the formula, R, A', R 10b, z, and R 13b are the same as above.)

[0245] In formula (b-S1-11), A' is preferably a methylene group, an oxygen atom (-O-), or a sulfur atom (-S-).

[0246] R 13b R is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. 13b Examples of the linear or branched alkylene group and the divalent linking group containing an oxygen atom in the above formula (I) include the same as the linear or branched alkylene group and the divalent linking group containing an oxygen atom described above, respectively.

[0247] As the constitutional unit represented by formula (b-S1-12), a constitutional unit represented by the following formula (b-S1-12a) or (b-S1-12b) is particularly preferable.

[0248] [ka] (In the formula, R and A' are the same as defined above, and c to e each independently represent an integer of 1 or more and 3 or less.)

[0249] [Structural unit (b-3-L)] Examples of the structural unit (b-3-L) include R 11b with a lactone-containing cyclic group, and more specific examples include structural units represented by the following formulas (b-L1) to (b-L5).

[0250] [ka] (In the formula, R is a hydrogen atom, an alkyl group having from 1 to 5 carbon atoms, or a halogenated alkyl group having from 1 to 5 carbon atoms; R' is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group, and R" is a hydrogen atom or an alkyl group; R 12b is a single bond or a divalent linking group, s″ is an integer of 0 to 2; 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; and r is 0 or 1.

[0251] R in the formulae (b-L1) to (b-L5) is the same as defined above. Examples of the alkyl group, alkoxy group, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group for R' include the same as those described above for the alkyl group, alkoxy group, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group listed as the substituent that the -SO- containing cyclic group may have, respectively.

[0252] Considering industrial availability and the like, R' is preferably a hydrogen atom. The alkyl group in R'' may be linear, branched, or cyclic. When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably has 1 to 5 carbon atoms. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkanes such as cyclopentane and cyclohexane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Examples of A" include the same as A' in the above formula (3-1). A" is preferably an alkylene group having 1 to 5 carbon atoms, an oxygen atom (-O-) or a sulfur atom (-S-), more preferably an alkylene group having 1 to 5 carbon atoms or -O-. As the alkylene group having 1 to 5 carbon atoms, a methylene group or a dimethylmethylene group is more preferable, and a methylene group is most preferable.

[0253] R 12b is R in the above formula (b-S1). 12b is the same as: In formula (b-L1), s″ is preferably 1 or 2. Specific examples of the structural units represented by the above formulas (b-L1) to (b-L3) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0254] [ka]

[0255] [ka]

[0256] [ka]

[0257] The structural unit (b-3-L) is preferably at least one selected from the group consisting of structural units represented by the above formulas (b-L1) to (b-L5), more preferably at least one selected from the group consisting of structural units represented by the above formulas (b-L1) to (b-L3), and particularly preferably at least one selected from the group consisting of structural units represented by the above formula (b-L1) or (b-L3). Among these, at least one selected from the group consisting of structural units represented by the aforementioned formulas (b-L1-1), (b-L1-2), (b-L2-1), (b-L2-7), (b-L2-12), (b-L2-14), (b-L3-1), and (b-L3-5) is preferred.

[0258] Furthermore, as the structural unit (b-3-L), structural units represented by the following formulas (b-L6) to (b-L7) are also preferred. [ka] In formulas (b-L6) and (b-L7), R and R 12b is the same as above.

[0259] The acrylic resin (B3) also contains structural units represented by the following formulas (b5) to (b7) having an acid-dissociable group as structural units that increase the solubility of the acrylic resin (B3) in alkali by the action of an acid.

[0260] [ka]

[0261] In the above formulas (b5) to (b7), R 14b , and R 18b ~R 23b each independently represents a hydrogen atom, a linear or branched alkyl group having from 1 to 6 carbon atoms, a fluorine atom, or a linear or branched fluorinated alkyl group having from 1 to 6 carbon atoms; R 15b ~R17b each independently represents a linear or branched alkyl group having from 1 to 6 carbon atoms, a linear or branched fluorinated alkyl group having from 1 to 6 carbon atoms, or an aliphatic cyclic group having from 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 they 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.

[0262] Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. A fluorinated alkyl group is an alkyl group in which some or all of the hydrogen atoms are substituted with fluorine atoms. Specific examples of the aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. Specific examples include groups in which one hydrogen atom has been removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In particular, groups in which one hydrogen atom has been removed from cyclohexane and adamantane (which may further have a substituent) are preferred.

[0263] Above R 16b and R 17b When R 15b , R 16b , and R 17b From the viewpoints of high contrast, resolution, focal depth range, etc., R is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a linear or branched alkyl group having 2 to 4 carbon atoms. 19b , R20b , R 22b , R 23b is preferably a hydrogen atom or a methyl group.

[0264] Above R 16b and R 17b may form an aliphatic cyclic group having 5 to 20 carbon atoms together with the carbon atom to which they are bonded. Specific examples of such an aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In particular, groups in which one or more hydrogen atoms have been removed from cyclohexane and adamantane (which may further have a substituent) are preferred.

[0265] Furthermore, the above R 16b and R 17b When the aliphatic cyclic group formed by has a substituent on its ring skeleton, examples of the substituent include polar groups such as a hydroxyl group, a carboxyl group, a cyano group, and an oxygen atom (=O), and linear or branched alkyl groups having 1 to 4 carbon atoms. An oxygen atom (=O) is particularly preferred as the polar group.

[0266] Above Y b is an aliphatic cyclic group or an alkyl group, and examples thereof include groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. Specific examples thereof include groups in which one or more hydrogen atoms have been removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In particular, groups in which one or more hydrogen atoms have been removed from adamantane (which may further have a substituent) are preferred.

[0267] Furthermore, the above Y b When the aliphatic cyclic group has a substituent on its ring skeleton, examples of the substituent include polar groups such as a hydroxyl group, a carboxyl group, a cyano group, and an oxygen atom (=O), and linear or branched alkyl groups having 1 to 4 carbon atoms. An oxygen atom (=O) is particularly preferred as the polar group.

[0268] Also, Y b When is an alkyl group, it is preferably a straight-chain or branched alkyl group having from 1 to 20 carbon atoms, preferably from 6 to 15. Such an alkyl group is particularly preferably an alkoxyalkyl group, and examples of such an alkoxyalkyl group include a 1-methoxyethyl group, a 1-ethoxyethyl group, a 1-n-propoxyethyl group, a 1-isopropoxyethyl group, a 1-n-butoxyethyl group, a 1-isobutoxyethyl group, a 1-tert-butoxyethyl group, a 1-methoxypropyl group, a 1-ethoxypropyl group, a 1-methoxy-1-methyl-ethyl group, and a 1-ethoxy-1-methylethyl group.

[0269] Specific preferred examples of the structural unit represented by formula (b5) above include those represented by formulas (b5-1) to (b5-33) below.

[0270] [ka]

[0271] In the above formulas (b5-1) to (b5-33), R 24b represents a hydrogen atom or a methyl group.

[0272] Specific preferred examples of the structural unit represented by formula (b6) above include those represented by formulas (b6-1) to (b6-26) below.

[0273] [ka]

[0274] In the above formulas (b6-1) to (b6-26), R 24b represents a hydrogen atom or a methyl group.

[0275] Specific preferred examples of the structural unit represented by formula (b7) above include those represented by formulas (b7-1) to (b7-15) below.

[0276] [ka]

[0277] In the above formulas (b7-1) to (b7-15), R 24b represents a hydrogen atom or a methyl group.

[0278] Among the constitutional units represented by the formulas (b5) to (b7) described above, the constitutional unit represented by the formula (b6) is preferred because it is easy to synthesize and relatively easy to achieve high sensitivity. b is preferably an alkyl group; 19b and R 20b A structural unit in which one or both of the following are alkyl groups is preferred.

[0279] Furthermore, the acrylic resin (B3) is preferably a resin made of a copolymer containing structural units derived from a polymerizable compound having an ether bond, in addition to the structural units represented by the above formulas (b5) to (b7).

[0280] Examples of the polymerizable compound having an ether bond include radical polymerizable compounds such as (meth)acrylic acid derivatives having an ether bond and an ester bond, and specific examples include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate. The polymerizable compound having an ether bond is preferably 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, or methoxytriethylene glycol (meth)acrylate. These polymerizable compounds may be used alone or in combination of two or more.

[0281] Furthermore, the acrylic resin (B3) may contain other polymerizable compounds as structural units in order to appropriately control the physical and chemical properties of the resin. Examples of such polymerizable compounds include known radical polymerizable compounds and anion polymerizable compounds.

[0282] Examples of such polymerizable compounds include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxy group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and cyclohexyl (meth)acrylate; and (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. esters; (meth)acrylic acid aryl esters such as phenyl (meth)acrylate and benzyl (meth)acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; vinyl group-containing aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; and amide bond-containing polymerizable compounds such as acrylamide and methacrylamide.

[0283] As described above, the acrylic resin (B3) may contain a structural unit derived from a polymerizable compound having a carboxy group, such as the monocarboxylic acids and dicarboxylic acids. However, from the viewpoint of facilitating the formation of a resist pattern including a non-resist portion having a rectangular cross-sectional shape, the ratio of the structural unit derived from a polymerizable compound having a carboxy group in the acrylic resin (B3) is preferably less than 20% by mass, more preferably 0.1% by mass or more and 15% by mass or less, and particularly preferably 1% by mass or more and 10% by mass or less.

[0284] Examples of the polymerizable compound include (meth)acrylic acid esters having an acid-non-dissociable aliphatic polycyclic group, vinyl group-containing aromatic compounds, etc. As the acid-non-dissociable aliphatic polycyclic group, tricyclodecanyl group, adamantyl group, tetracyclododecanyl group, isobornyl group, norbornyl group, etc. are particularly preferred in terms of industrial availability, etc. These aliphatic polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

[0285] Specific examples of the (meth)acrylic acid esters having an acid non-dissociable aliphatic polycyclic group include those having structures represented by the following formulae (b8-1) to (b8-5).

[0286] [ka]

[0287] In the above formulas (b8-1) to (b8-5), R 25b represents a hydrogen atom or a methyl group.

[0288] When the acrylic resin (B3) contains a structural unit (b-3) containing an -SO2- containing cyclic group or a lactone-containing cyclic group, the content of the structural unit (b-3) in the acrylic resin (B3) is preferably 50 mass% or less, and more preferably 30 mass% or less.

[0289] The acrylic resin (B3) preferably contains 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 10% by mass or more and 50% by mass or less, of the structural units represented by the above formulas (b5) to (b7).

[0290] The acrylic resin (B3) preferably contains a structural unit derived from the polymerizable compound having an ether bond. The content of the structural unit derived from the polymerizable compound having an ether bond in the acrylic resin (B3) is preferably 0% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and even more preferably 5% by mass or more and 30% by mass or less.

[0291] The acrylic resin (B3) preferably contains a structural unit derived from a (meth)acrylic acid ester having an acid non-dissociable aliphatic polycyclic group. The content of the structural unit derived from a (meth)acrylic acid ester having an acid non-dissociable aliphatic polycyclic group in the acrylic resin (B3) is preferably 0% by mass or more and 60% by mass or less, more preferably 5% by mass or more and 50% by mass or less, and even more preferably 5% by mass or more and 30% by mass or less.

[0292] As long as the photosensitive composition contains a predetermined amount of the acrylic resin (B3), an acrylic resin other than the acrylic resin (B3) described above can also be used as the resin (B). Such an acrylic resin other than the acrylic resin (B3) is not particularly limited as long as it is a resin containing the structural units represented by the above formulas (b5) to (b7).

[0293] The polystyrene-equivalent mass average molecular weight of the resin (B) described above is preferably from 10,000 to 600,000, more preferably from 20,000 to 400,000, and even more preferably from 30,000 to 300,000. By setting the mass average molecular weight in this range, it is possible to maintain sufficient strength of the photosensitive layer made of the photosensitive composition without reducing the releasability from the substrate, and further to easily prevent swelling of the profile and the occurrence of cracks during plating.

[0294] The polydispersity of the resin (B) is preferably 1.05 or more. Here, the polydispersity is the value obtained by dividing the mass average molecular weight by the number average molecular weight. By setting the polydispersity in this range, it is possible to avoid the problem of the desired stress resistance to plating and the tendency of the metal layer obtained by plating to swell.

[0295] The content of the resin (B) is preferably from 5% by mass to 70% by mass based on the total mass of the photosensitive composition. The content of the resin (B) is preferably from 5 to 99% by mass, and more preferably from 50 to 99% by mass, based on the total solid content by mass of the photosensitive composition.

[0296] <Acid diffusion suppressant (C)> The photosensitive composition preferably further contains an acid diffusion inhibitor (C) in order to improve the shape of the resist pattern, the laying stability of the photosensitive resin film, etc. As the acid diffusion inhibitor (C), a nitrogen-containing compound (C1) is preferable, and an organic carboxylic acid, or a phosphorus oxo acid or a derivative thereof (C2) can be further contained as necessary.

[0297] [Nitrogen-containing compounds (C1)] Examples of the nitrogen-containing compound (C1) include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tri-n-pentylamine, tribenzylamine, diethanolamine, triethanolamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, formamide, N-methylformamide, N,N- Examples of the monomer include 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-oxyquinoline, acridine, purine, pyrrolidine, piperidine, 2,4,6-tri(2-pyridyl)-S-triazine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, pyridine, etc. These may be used alone or in combination of two or more.

[0298] In addition, commercially available hindered amine compounds such as ADK STAB LA-52, ADK STAB LA-57, ADK STAB LA-63P, ADK STAB LA-68, ADK STAB LA-72, ADK STAB LA-77Y, ADK STAB LA-77G, ADK STAB LA-81, ADK STAB LA-82, and ADK STAB LA-87 (all manufactured by ADEKA CORPORATION), and 4-hydroxy-1,2,2,6,6-pentamethylpiperidine derivatives, and pyridines in which the 2,6-positions are substituted with substituents such as hydrocarbon groups, such as 2,6-diphenylpyridine and 2,6-di-tert-butylpyridine, can also be used as the nitrogen-containing compound (C1).

[0299] The nitrogen-containing compound (C1) is usually used in an amount of 0 to 5 parts by mass, and particularly preferably in an amount of 0 to 3 parts by mass, per 100 parts by mass of the combined total of the resin (B) and the alkali-soluble resin (D) described below.

[0300] [Organic carboxylic acids, phosphorus oxoacids or their derivatives (C2)] Of the organic carboxylic acids or phosphorus oxoacids or derivatives thereof (C2), specifically, suitable organic carboxylic acids include malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc., with salicylic acid being particularly preferred.

[0301] Examples of phosphorus oxoacids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester, and other phosphoric acid and ester derivatives thereof; phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester, and other phosphonic acid and ester derivatives thereof; phosphinic acid, phosphinic acid phenylphosphinic acid, and other ester derivatives thereof; and the like. Among these, phosphonic acid is particularly preferred. These may be used alone or in combination of two or more.

[0302] The organic carboxylic acid, or phosphorus oxoacid or its derivative (C2) is usually used in a range of 0 to 5 parts by mass, and particularly preferably in a range of 0 to 3 parts by mass, per 100 parts by mass of the combined mass of the above resin (B) and the alkali-soluble resin (D) described below.

[0303] In order to form a salt and stabilize the resulting mixture, it is preferable to use the organic carboxylic acid, or phosphorus oxoacid or its derivative (C2) in an amount equivalent to that of the nitrogen-containing compound (C1).

[0304] <Alkali-soluble resin (D)> The photosensitive composition may not contain an alkali-soluble resin (D), but may contain an alkali-soluble resin (D). Here, the alkali-soluble resin refers to a resin that dissolves to a depth of 0.01 μm or more when a resin film having a thickness of 1 μm is formed on a substrate using a resin solution having a resin concentration of 20% by mass (solvent: propylene glycol monomethyl ether acetate) and is immersed in a 2.38% by mass aqueous TMAH solution for 1 minute, and does not fall under the above-mentioned resin (B) (typically, it refers to a resin whose alkali solubility does not substantially change even under the action of an acid). The alkali-soluble resin (D) is preferably at least one resin selected from the group consisting of novolac resin (D1), polyhydroxystyrene resin (D2), and acrylic resin (D3).

[0305] [Novolac resin (D1)] Novolak resins can be obtained, for example, by addition condensation of aromatic compounds having a phenolic hydroxyl group (hereinafter simply referred to as "phenols") with aldehydes in the presence of an acid catalyst.

[0306] Examples of the phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, phloroglucinol, hydroxydiphenyl, bisphenol A, gallic acid, gallic acid esters, α-naphthol, and β-naphthol. Examples of the aldehydes include formaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, and acetaldehyde. The catalyst used in the addition condensation reaction is not particularly limited, but examples of acid catalysts that can be used include hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, and acetic acid.

[0307] The flexibility of the novolak resin can be further improved by using o-cresol, substituting the hydrogen atoms of the hydroxyl groups in the resin with other substituents, or using bulky aldehydes.

[0308] The mass average molecular weight of the novolak resin (D1) is not particularly limited as long as it does not impair the object of the present invention, but is preferably 1,000 or more and 50,000 or less.

[0309] [Polyhydroxystyrene resin (D2)] Examples of the hydroxystyrene-based compound constituting the polyhydroxystyrene resin (D2) include p-hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene. Furthermore, the polyhydroxystyrene resin (D2) is preferably a copolymer with a styrene resin. Examples of the styrene-based compound constituting such a styrene resin include styrene, chlorostyrene, chloromethylstyrene, vinyltoluene, and α-methylstyrene.

[0310] The mass average molecular weight of the polyhydroxystyrene resin (D2) is not particularly limited as long as it does not impair the object of the present invention, but is preferably 1,000 or more and 50,000 or less.

[0311] [Acrylic resin (D3)] The acrylic resin (D3) preferably contains a structural unit derived from a polymerizable compound having an ether bond, and a structural unit derived from a polymerizable compound having a carboxy group.

[0312] Examples of the polymerizable compound having an ether bond include (meth)acrylic acid derivatives having an ether bond and an ester bond, such as 2-methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate. The polymerizable compound having an ether bond is preferably 2-methoxyethyl acrylate or methoxytriethylene glycol acrylate. These polymerizable compounds may be used alone or in combination of two or more.

[0313] Examples of the polymerizable compound having a carboxy group include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; and compounds having a carboxy group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid. The polymerizable compound having a carboxy group is preferably acrylic acid or methacrylic acid. These polymerizable compounds may be used alone or in combination of two or more.

[0314] The mass average molecular weight of the acrylic resin (D3) is not particularly limited as long as it does not impair the object of the present invention, but is preferably 50,000 or more and 800,000 or less.

[0315] The content of the alkali-soluble resin (D) is preferably 0 to 80 parts by mass, more preferably 0 to 60 parts by mass, when the total of the resin (B) and the alkali-soluble resin (D) is 100 parts by mass. By setting the content of the alkali-soluble resin (D) within the above range, there is a tendency that film loss during development can be prevented.

[0316] <Sulfur-containing compounds (E)> When the photosensitive composition is used for forming a pattern on a metal substrate, the photosensitive composition preferably contains a sulfur-containing compound (E). The sulfur-containing compound (E) is a compound containing a sulfur atom that can be coordinated to a metal. In addition, regarding a compound that can produce two or more tautomers, if at least one tautomer contains a sulfur atom that can be coordinated to a metal that constitutes the surface of a metal substrate, the compound corresponds to a sulfur-containing compound. When a resist pattern used as a plating mold is formed on a surface made of a metal such as Cu, defects in the cross-sectional shape such as footing are likely to occur. However, when the photosensitive composition contains a sulfur-containing compound (E), the occurrence of defects in the cross-sectional shape such as footing is easily suppressed even when a resist pattern is formed on a surface made of a metal of a substrate. Note that "footing" refers to a phenomenon in which the bottom width of the non-resist portion is narrower than the top width, as a result of the resist portion protruding toward the non-resist portion near the contact surface between the substrate surface and the resist pattern. When the photosensitive composition is used for pattern formation on a substrate other than a metal substrate, the photosensitive composition does not need to contain a sulfur-containing compound.When the photosensitive composition is used for pattern formation on a substrate other than a metal substrate, the photosensitive composition preferably does not contain a sulfur-containing compound (E) because the number of components in the photosensitive composition is reduced, making the photosensitive composition easier to manufacture and reducing the manufacturing cost of the photosensitive composition. Incidentally, there is no particular problem caused by the inclusion of the sulfur-containing compound (E) in a photosensitive composition used for forming a pattern on a substrate other than a metal substrate.

[0317] The sulfur atom capable of coordinating to a metal is contained in the sulfur-containing compound as, for example, a mercapto group (-SH), a thiocarboxy group (-CO-SH), a dithiocarboxy group (-CS-SH), a thiocarbonyl group (-CS-), and the like. The sulfur-containing compound preferably has a mercapto group, since this facilitates coordination with metals and has an excellent effect of suppressing footing.

[0318] A preferred example of the sulfur-containing compound having a mercapto group is a compound represented by the following formula (e1). [ka] (In the formula, R e1 and R e2 each independently represents a hydrogen atom or an alkyl group; R e3 represents a single bond or an alkylene group, R e4represents an aliphatic group having a valence of u which may contain atoms other than carbon, and u represents an integer of 2 or more and 4 or less.

[0319] R e1 and R e2 When R is an alkyl group, the alkyl group may be linear or branched, and is preferably linear. e1 and R e2 When R is an alkyl group, the number of carbon atoms in the alkyl group is not particularly limited as long as it does not impair the object of the present invention. The number of carbon atoms in the alkyl group is preferably 1 or more and 4 or less, more preferably 1 or 2, and most preferably 1. e1 and R e2 As for the combination of these, one is preferably a hydrogen atom and the other an alkyl group, and particularly preferably one is a hydrogen atom and the other a methyl group.

[0320] R e3 When R is an alkylene group, the alkylene group may be linear or branched, and is preferably linear. e3 When is an alkylene group, the number of carbon atoms of the alkylene group is not particularly limited as long as it does not impair the object of the present invention. The number of carbon atoms of the alkylene group is preferably 1 to 10, more preferably 1 to 5, particularly preferably 1 or 2, and most preferably 1.

[0321] R e4 R is a divalent to tetravalent aliphatic group which may contain atoms other than carbon. e4 Examples of atoms other than carbon that may be contained in R include a nitrogen atom, an oxygen atom, a sulfur atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. e4 The structure of the aliphatic group may be linear, branched, or cyclic, or may be a combination of these structures.

[0322] Among the compounds represented by formula (e1), a compound represented by the following formula (e2) is more preferred. [ka] (In formula (e2), R e4 and u are the same as in formula (e1).

[0323] Among the compounds represented by the above formula (e2), the following compounds are preferred. [ka]

[0324] Compounds represented by the following formulae (e3-L1) to (e3-L7) are also preferred examples of the sulfur-containing compound having a mercapto group. [ka] (In formulae (e3-L1) to (e3-L7), R', s", A", and r are the same as those in formulae (b-L1) to (b-L7) described above for the acrylic resin (B3).)

[0325] Preferred specific examples of the mercapto compounds represented by the above formulas (e3-L1) to (e3-L7) include the following compounds. [ka]

[0326] Compounds represented by the following formulas (e3-1) to (e3-4) are also preferred examples of the sulfur-containing compound having a mercapto group. [ka] (The definitions of the abbreviations in the formulae (e3-1) to (e3-4) are as described above for the acrylic resin (B3) and for the formulae (3-1) to (3-4).)

[0327] Preferred specific examples of the mercapto compounds represented by the above formulas (e3-1) to (e3-4) include the following compounds.

[0328] [ka]

[0329] Moreover, a suitable example of the compound having a mercapto group is a compound represented by the following formula (e4). [ka] (In formula (e4), R e5 is a group selected from the group consisting of a hydroxyl group, an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, an alkylthio group having from 1 to 4 carbon atoms, a hydroxyalkyl group having from 1 to 4 carbon atoms, a mercaptoalkyl group having from 1 to 4 carbon atoms, a halogenated alkyl group having from 1 to 4 carbon atoms, and a halogen atom; n1 is an integer of 0 to 3, n0 is an integer of 0 to 3; when n1 is 2 or 3, R e5 may be the same or different.)

[0330] R e5 Specific examples of the alkyl group having 1 to 4 carbon atoms which may have a hydroxyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these alkyl groups, a methyl group, a hydroxymethyl group, and an ethyl group are preferred.

[0331] R e5 Specific examples of when is an alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, and a tert-butyloxy group. Among these alkoxy groups, a methoxy group and an ethoxy group are preferred, and a methoxy group is more preferred.

[0332] R e5Specific examples of when is an alkylthio group having 1 to 4 carbon atoms include a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butylthio group, an isobutylthio group, a sec-butylthio group, and a tert-butylthio group. Among these alkylthio groups, a methylthio group and an ethylthio group are preferred, and a methylthio group is more preferred.

[0333] R e5 Specific examples of the hydroxyalkyl group having 1 to 4 carbon atoms include a hydroxymethyl group, a 2-hydroxyethyl group, a 1-hydroxyethyl group, a 3-hydroxy-n-propyl group, and a 4-hydroxy-n-butyl group. Among these hydroxyalkyl groups, a hydroxymethyl group, a 2-hydroxyethyl group, and a 1-hydroxyethyl group are preferred, and a hydroxymethyl group is more preferred.

[0334] R e5 Specific examples of the mercaptoalkyl group having 1 to 4 carbon atoms include a mercaptomethyl group, a 2-mercaptoethyl group, a 1-mercaptoethyl group, a 3-mercapto-n-propyl group, and a 4-mercapto-n-butyl group. Among these mercaptoalkyl groups, a mercaptomethyl group, a 2-mercaptoethyl group, and a 1-mercaptoethyl group are preferred, and a mercaptomethyl group is more preferred.

[0335] R e5 When R is a halogenated alkyl group having 1 to 4 carbon atoms, examples of the halogen atom contained in the halogenated alkyl group include fluorine, chlorine, bromine, and iodine. e5Specific examples of the halogenated alkyl group having 1 to 4 carbon atoms include a chloromethyl group, a bromomethyl group, an iodomethyl group, a fluoromethyl group, a dichloromethyl group, a dibromomethyl group, a difluoromethyl group, a trichloromethyl group, a tribromomethyl group, a trifluoromethyl group, a 2-chloroethyl group, a 2-bromoethyl group, a 2-fluoroethyl group, a 1,2-dichloroethyl group, a 2,2-difluoroethyl group, a 1-chloro-2-fluoroethyl group, a 3-chloro-n-propyl group, a 3-bromo-n-propyl group, a 3-fluoro-n-propyl group, and a 4-chloro-n-butyl group. Among these halogenated alkyl groups, a chloromethyl group, a bromomethyl group, an iodomethyl group, a fluoromethyl group, a dichloromethyl group, a dibromomethyl group, a difluoromethyl group, a trichloromethyl group, a tribromomethyl group, and a trifluoromethyl group are preferred, and a chloromethyl group, a dichloromethyl group, a trichloromethyl group, and a trifluoromethyl group are more preferred.

[0336] R e5 Specific examples of when is a halogen atom include fluorine, chlorine, bromine, and iodine.

[0337] In formula (e4), n1 is an integer of 0 to 3, and more preferably 1. When n1 is 2 or 3, a plurality of R e5 may be the same or different.

[0338] In the compound represented by formula (e4), R on the benzene ring e5 The substitution position of R on the benzene ring is not particularly limited. e5 The substitution position is -(CH2) n0 It is preferably in the meta or para position relative to the bonding position of --SH.

[0339] The compound represented by formula (e4) is R e5 As R, a compound having at least one group selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a mercaptoalkyl group is preferred. e5More preferably, the compound represented by formula (e4) has one group selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a mercaptoalkyl group as R e5 When the alkyl group has one group selected from the group consisting of an alkyl group, a hydroxyalkyl group, and a mercaptoalkyl group, the substitution position of the alkyl group, the hydroxyalkyl group, or the mercaptoalkyl group on the benzene ring is -(CH2) n0 It is preferably at the meta or para position relative to the bonding position of --SH, and more preferably at the para position.

[0340] In formula (e4), n0 is an integer of 0 to 3. In terms of ease of preparation and availability of the compound, n0 is preferably 0 or 1, and more preferably 0.

[0341] Specific examples of the compound represented by formula (e4) include p-mercaptophenol, p-thiocresol, m-thiocresol, 4-(methylthio)benzenethiol, 4-methoxybenzenethiol, 3-methoxybenzenethiol, 4-ethoxybenzenethiol, 4-isopropyloxybenzenethiol, 4-tert-butoxybenzenethiol, 3,4-dimethoxybenzenethiol, 3,4,5-trimethoxybenzenethiol, 4-ethylbenzenethiol, 4-isopropylbenzenethiol, 4-n-butylbenzenethiol, 4 -tert-Butylbenzenethiol, 3-ethylbenzenethiol, 3-isopropylbenzenethiol, 3-n-butylbenzenethiol, 3-tert-butylbenzenethiol, 3,5-dimethylbenzenethiol, 3,4-dimethylbenzenethiol, 3-tert-butyl-4-methylbenzenethiol, 3-tert-4-methylbenzenethiol, 3-tert-butyl-5-methylbenzenethiol, 4-tert-butyl-3-methylbenzenethiol, 4-mercaptobenzyl alcohol, 3-mercaptobenzyl alcohol benzenethiol, 4-(mercaptomethyl)phenol, 3-(mercaptomethyl)phenol, 1,4-di(mercaptomethyl)phenol, 1,3-di(mercaptomethyl)phenol, 4-fluorobenzenethiol, 3-fluorobenzenethiol, 4-chlorobenzenethiol, 3-chlorobenzenethiol, 4-bromobenzenethiol, 4-iodobenzenethiol, 3-bromobenzenethiol, 3,4-dichlorobenzenethiol, 3,5-dichlorobenzenethiol, 3,4-difluorobenzenethiol, 3,5-difluorobenzenethiol thiol, 4-mercaptocatechol, 2,6-di-tert-butyl-4-mercaptophenol, 3,5-di-tert-butyl-4-methoxybenzenethiol, 4-bromo-3-methylbenzenethiol, 4-(trifluoromethyl)benzenethiol, 3-(trifluoromethyl)benzenethiol, 3,5-bis(trifluoromethyl)benzenethiol, 4-methylthiobenzenethiol, 4-ethylthiobenzenethiol, 4-n-butylthiobenzenethiol, and 4-tert-butylthiobenzenethiol.

[0342] Examples of the sulfur-containing compound having a mercapto group include a compound containing a nitrogen-containing aromatic heterocycle substituted with a mercapto group, and a tautomer of a compound containing a nitrogen-containing aromatic heterocycle substituted with a mercapto group. Specific preferred examples of the nitrogen-containing aromatic heterocycle include imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, oxazole, thiazole, pyridine, pyrimidine, pyridazine, pyrazine, 1,2,3-triazine, 1,2,4-triazine, 1,3,5-triazine, indole, indazole, benzimidazole, benzoxazole, benzothiazole, 1H-benzotriazole, quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline, and 1,8-naphthyridine.

[0343] Specific examples of suitable nitrogen-containing heterocyclic compounds as the sulfur-containing compound and suitable tautomers of the nitrogen-containing heterocyclic compounds include the following compounds. [ka]

[0344] When the photosensitive composition contains the sulfur-containing compound (E), the amount used is preferably from 0.01 to 5 parts by mass, more preferably from 0.02 to 3 parts by mass, and particularly preferably from 0.05 to 2 parts by mass, per 100 parts by mass of the combined mass of the resin (B) and the alkali-soluble resin (D).

[0345] <Dye (F)> The photosensitive composition may contain a dye (F). Examples of the dye (F) include azo compounds and curcumin, but other dyes may also be used. Specific examples of the dye (F) include 2-benzeneazo-4-methylphenol, 2,2',4,4'-tetrahydroxybenzophenone, 4-dimethylamino-2',4'-dihydroxybenzophenone, 5-amino-3-methyl-1-phenyl-4-(4-hydroxyphenylazo)pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylamino-4'-ethoxyazobenzene, 4-diethylaminoazobenzene, curcumin, 1,7-bis(3-methoxy-4-hydroxyphenyl)-1,6-heptadiene-3,5-dione, and 5-hydroxy-4-(4-methoxyphenylazo)-3-methyl-1-phenylpyrazole.

[0346] When the photosensitive composition contains the dye (F), the amount used is preferably from 0.0005 to 5 parts by mass, more preferably from 0.001 to 3 parts by mass, and particularly preferably from 0.003 to 1 part by mass, per 100 parts by mass of the combined mass of the resin (B) and the alkali-soluble resin (D).

[0347] <Organic solvent (S)> The photosensitive composition preferably contains an organic solvent (S). The type of organic solvent (S) is not particularly limited as long as it does not impair the object of the present invention, and may be appropriately selected from organic solvents that have been conventionally used in photosensitive compositions.

[0348] Specific examples of the organic solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; polyhydric alcohols and derivatives thereof such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether acetate, dipropylene glycol, and monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, and monophenyl ether of dipropylene glycol monoacetate; Examples of the cyclic ethers include oxane, ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, and other esters; aromatic hydrocarbons such as toluene and xylene; and the like. These may be used alone or in combination of two or more.

[0349] The organic solvent (S) is used in such a range that the solids concentration of the photosensitive composition becomes 25% by mass or more and 70% by mass or less, preferably 30% by mass or more and 60% by mass or less, and more preferably 40% by mass or more and 50% by mass or less.

[0350] <Other ingredients> The photosensitive composition may further contain a polyvinyl resin to improve plasticity. 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. The polyvinyl resin is preferably polyvinyl methyl ether in view of its low glass transition point.

[0351] The photosensitive composition may contain a Lewis acid compound. By containing a Lewis acid compound in the photosensitive composition, a photosensitive composition with high sensitivity is easily obtained, and it is easier to form a resist pattern having a rectangular cross-sectional shape using the photosensitive composition. In addition, when a pattern is formed using a photosensitive composition, if the time required for each step in forming the pattern or the time required between each step is long, adverse effects such as difficulty in forming a pattern of the desired shape or dimensions, deterioration of developability, etc. However, by blending a Lewis acid compound in the photosensitive composition, such adverse effects on the pattern shape and developability can be alleviated, and the process margin can be widened.

[0352] Here, the Lewis acid compound means "a compound that has a vacant orbital capable of accepting at least one electron pair and acts as an electron pair acceptor." The Lewis acid compound is not particularly limited as long as it meets the above definition and is recognized as a Lewis acid compound by those skilled in the art. As the Lewis acid compound, a compound that does not fall under the category of a Bronsted acid (protonic acid) is preferably used. Specific examples of Lewis acid compounds include boron fluoride, boron fluoride ether complexes (e.g., BF3·Et2O, BF3·Me2O, BF3·THF, etc., where Et is an ethyl group, Me is a methyl group, and THF is tetrahydrofuran), organic boron compounds (e.g., tri-n-octyl borate, tri-n-butyl borate, triphenyl borate, and triphenyl boron, etc.), titanium chloride, aluminum chloride, aluminum bromide, and gallium chloride. Examples of the metal ions that can be used include tin, gallium bromide, indium chloride, thallium trifluoroacetate, tin chloride, zinc chloride, zinc bromide, zinc iodide, zinc trifluoromethanesulfonate, zinc acetate, zinc nitrate, zinc tetrafluoroborate, manganese chloride, manganese bromide, nickel chloride, nickel bromide, nickel cyanide, nickel acetylacetonate, cadmium chloride, cadmium bromide, stannous chloride, stannous bromide, stannous sulfate, and stannous tartrate. Other specific examples of Lewis acidic compounds include chlorides, bromides, sulfates, nitrates, carboxylates, and trifluoromethanesulfonates of rare earth metal elements, cobalt chloride, ferrous chloride, and yttrium chloride. Here, examples of rare earth metal elements include lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

[0353] The Lewis acid compound preferably contains a Lewis acid compound containing an element of Group 13 of the periodic table, since it is easily available and the effect of its addition is good. Here, the Group 13 elements of the periodic table include boron, aluminum, gallium, indium, and thallium. Among the above-mentioned elements of Group 13 of the periodic table, boron is preferred because of the ease of availability of Lewis acid compounds and the particularly excellent effect of adding it, i.e., the Lewis acid compound preferably contains a Lewis acid compound containing boron.

[0354] Examples of Lewis acid compounds containing boron include boron halides such as boron fluoride, ether complexes of boron fluoride, boron chloride, and boron bromide, as well as various organic boron compounds. As Lewis acid compounds containing boron, organic boron compounds are preferred because they have a low content of halogen atoms and are therefore easy to apply to applications in which a low halogen content is required for the photosensitive composition.

[0355] A preferred example of the organic boron compound is represented by the following formula (f1): B(R f1 ) t1 (OR f2 ) (3-t1) (f1) (In formula (f1), R f1 and R f2are each independently a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have one or more substituents; t1 is an integer of 0 to 3; R f1 If there are multiple R f1 two of the groups may be bonded together to form a ring, and OR f2 If multiple exists, multiple OR f2 Two of the may be bonded to each other to form a ring. The photosensitive composition preferably contains, as a Lewis acid compound, at least one of the boron compounds represented by the above formula (f1).

[0356] In formula (f1), R f1 and R f2 When is a hydrocarbon group, the number of carbon atoms in the hydrocarbon group is from 1 to 20. The hydrocarbon group having from 1 to 20 carbon atoms may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a hydrocarbon group formed from a combination of an aliphatic group and an aromatic group. The hydrocarbon group having 1 to 20 carbon atoms is preferably a saturated aliphatic hydrocarbon group or an aromatic hydrocarbon group. f1 and R f2 The number of carbon atoms in the hydrocarbon group as the alkyl group is preferably 1 or more and 10 or less. When the hydrocarbon group is an aliphatic hydrocarbon group, the number of carbon atoms therein is more preferably 1 or more and 6 or less, and particularly preferably 1 or more and 4 or less. R f1 and R f2 The hydrocarbon group as may be a saturated or unsaturated hydrocarbon group, and is preferably a saturated hydrocarbon group. R f1 and R f2 When the hydrocarbon group as the alkyl group is an aliphatic hydrocarbon group, the aliphatic hydrocarbon group may be linear, branched, or cyclic, or may be a combination of these structures.

[0357] Specific examples of suitable aromatic hydrocarbon groups include a phenyl group, a naphthalene-1-yl group, a naphthalene-2-yl group, a 4-phenylphenyl group, a 3-phenylphenyl group, and a 2-phenylphenyl group. Of these, a phenyl group is preferred.

[0358] The saturated aliphatic hydrocarbon group is preferably an alkyl group. Specific examples of suitable alkyl groups include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, and an n-decyl group.

[0359] R f1 and R f2 The hydrocarbon group as may have one or more substituents. Examples of the substituents include a halogen atom, a hydroxyl group, an alkyl group, an aralkyl group, an alkoxy group, a cycloalkyloxy group, an aryloxy group, an aralkyloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an aralkylthio group, an acyl group, an acyloxy group, an acylthio group, an alkoxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an amino group, an N-monosubstituted amino group, an N,N-disubstituted amino group, a carbamoyl group (-CO-NH2), an N-monosubstituted carbamoyl group, an N,N-disubstituted carbamoyl group, a nitro group, and a cyano group. The number of carbon atoms of the substituent is not particularly limited as long as it does not impair the object of the present invention, but is preferably 1 or more and 10 or less, and more preferably 1 or more and 6 or less.

[0360] Specific examples of suitable organoboron compounds represented by the above formula (f1) include the following compounds: In the following formula, Pen represents a pentyl group, Hex represents a hexyl group, Hep represents a heptyl group, Oct represents an octyl group, Non represents a nonyl group, and Dec represents a decyl group.

[0361] [ka]

[0362] [ka]

[0363] [ka]

[0364] [ka]

[0365] [ka]

[0366] The Lewis acid compound is preferably used in an amount of 0.01 to 5 parts by mass, more preferably 0.01 to 3 parts by mass, and even more preferably 0.05 to 2 parts by mass, relative to 100 parts by mass of the combined mass of the resin (B) and the alkali-soluble resin (D).

[0367] In addition, when the photosensitive composition is used to form a pattern that will serve as a mold for forming a plated object, the photosensitive composition may further contain an adhesion aid in order to improve adhesion between the mold formed using the photosensitive composition and a metal substrate.

[0368] The photosensitive composition may further contain a surfactant in order to improve coating properties, defoaming properties, leveling properties, etc. As the surfactant, for example, a fluorine-based surfactant or a silicone-based surfactant is preferably used. Specific examples of fluorine-based surfactants include commercially available fluorine-based surfactants such as BM-1000, BM-1100 (all manufactured by BM Chemie), Megafac F142D, Megafac F172, Megafac F173, Megafac F183 (all manufactured by Dainippon Ink and Chemicals), 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 Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, and SF-8428 (all manufactured by Toray Silicones), but are not limited thereto. As the silicone surfactant, an unmodified silicone surfactant, a polyether-modified silicone surfactant, a polyester-modified silicone surfactant, an alkyl-modified silicone surfactant, an aralkyl-modified silicone surfactant, a reactive silicone surfactant, and the like can be preferably used. As the silicone surfactant, commercially available silicone surfactants can be used. Specific examples of commercially available silicone surfactants include Paintad M (manufactured by Toray Dow Corning Co., Ltd.), Topika K1000, Topika K2000, Topika K5000 (all manufactured by Takachiho Sangyo Co., Ltd.), XL-121 (polyether-modified silicone surfactant, manufactured by Clariant), and BYK-310 (polyester-modified silicone surfactant, manufactured by BYK-Chemie Co., Ltd.).

[0369] The photosensitive composition may further contain an acid or an acid anhydride in order to finely adjust the solubility in the developer.

[0370] Specific examples of acids and acid anhydrides include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, and cinnamic acid; hydroxymonocarboxylic acids such as lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid, and syringic acid; oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, butanetetracarboxylic acid, and trimellitic acid. Examples of the acid anhydride include polyvalent carboxylic acids such as itaconic anhydride, pyromellitic anhydride, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, and 1,2,5,8-naphthalenetetracarboxylic acid; and acid anhydrides such as itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenylsuccinic anhydride, tricarbanilic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, himic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bistrimellitate anhydride, and glycerin tristrimellitate anhydride.

[0371] The photosensitive composition may further contain a well-known sensitizer to improve the sensitivity.

[0372] The photosensitive composition is prepared by mixing and stirring the above-mentioned components in a conventional manner. Examples of devices that can be used to mix and stir the above-mentioned components include a dissolver, a homogenizer, and a three-roll mill. After the above-mentioned components are mixed uniformly, the resulting mixture may be filtered using a mesh, a membrane filter, or the like.

[0373] The photosensitive composition described above has excellent storage stability, and therefore, even if a long period of time (e.g., 2 weeks) has passed since the photosensitive composition was prepared, or even if the photosensitive composition is stored at a relatively high temperature (e.g., 40° C.), the change in viscosity is suppressed.

[0374] <Photosensitive dry film and method for manufacturing photosensitive dry film> The photosensitive dry film has a substrate film and a photosensitive layer formed on the surface of the substrate film, and the photosensitive layer is made of the above-mentioned photosensitive composition.

[0375] The substrate film is preferably one having optical transparency, specifically, polyethylene terephthalate (PET) film, polypropylene (PP) film, polyethylene (PE) film, etc., and polyethylene terephthalate (PET) film is preferred because of its excellent balance between optical transparency and breaking strength.

[0376] The above-mentioned photosensitive composition is applied onto a substrate film to form a photosensitive layer, thereby producing a photosensitive dry film. When forming a photosensitive layer on a substrate film, a photosensitive composition is applied onto the substrate film using an applicator, a bar coater, a wire bar coater, a roll coater, a curtain flow coater, or the like, so that the film thickness after drying is preferably 0.5 μm or more and 300 μm or less, more preferably 1 μm or more and 300 μm or less, and particularly preferably 3 μm or more and 100 μm or less, and then dried. The above-mentioned photosensitive composition has a high solid concentration and is therefore suitable for forming a thick photosensitive layer (for example, 70 μm or more).

[0377] The photosensitive dry film may further have a protective film on the photosensitive layer, such as a polyethylene terephthalate (PET) film, a polypropylene (PP) film, or a polyethylene (PE) film.

[0378] <Method for manufacturing patterned resist film and substrate with mold> The method for forming a patterned resist film on a substrate using the above-described photosensitive composition is not particularly limited. Such a patterned resist film is suitably used as an insulating film, an etching mask, a mold for forming a plating object, and the like. A preferred method is as follows: a lamination step of laminating a photosensitive layer made of a photosensitive composition on a substrate; an exposure step of exposing the photosensitive layer to actinic rays or radiation in a position-selective manner; a developing step of developing the exposed photosensitive layer; The present invention relates to a method for producing a patterned resist film, comprising the steps of: The manufacturing method of a mold-bearing substrate equipped with a mold for forming a plated object is similar to the manufacturing method of a patterned resist film, except that it uses a substrate having a metal surface as the substrate, and includes a step of laminating a photosensitive layer on the metal surface of the substrate having a metal surface, and that in the development step, a mold for forming a plated object by development is produced.

[0379] The substrate on which the photosensitive layer is laminated is not particularly limited, and may be a conventionally known substrate, such as a substrate for electronic components, a substrate on which a predetermined wiring pattern is formed, etc. The substrate may also be a silicon substrate, a glass substrate, etc. When manufacturing a template-attached substrate having a template for forming a plated object, a substrate having a metal surface is used as the substrate. The metal species constituting the metal surface is preferably copper, gold, or aluminum, and more preferably copper.

[0380] The photosensitive layer is laminated on the substrate, for example, as follows. That is, a liquid photosensitive composition is applied onto the substrate, and the solvent is removed by heating to form a photosensitive layer with a desired thickness. The thickness of the photosensitive layer is not particularly limited as long as the resist pattern can be formed with a desired thickness. The thickness of the photosensitive layer is not particularly limited, but is preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 10 μm or more, and can also be a thick film of 70 μm or more or 100 μm or more. The upper limit of the thickness is, for example, 300 μm or less. The above-mentioned photosensitive composition has a high solid content concentration, and therefore can form a thick photosensitive layer, and can therefore be preferably used for forming a plated object, for example.

[0381] The method of applying the photosensitive composition onto the substrate may be a spin coat method, a slit coat method, a roll coat method, a screen printing method, an applicator method, or the like. It is preferable to prebake the photosensitive layer. The prebake conditions vary depending on the type of each component in the photosensitive composition, the blending ratio, the coating film thickness, and the like, but are usually 70°C to 200°C, preferably 80°C to 150°C, and about 2 minutes to 120 minutes. Prebake may be performed multiple times in two or more stages. For example, after performing a first stage prebake at a temperature of 70°C to 120°C, a second stage prebake may be performed at a temperature higher than that of the first stage.

[0382] The photosensitive layer formed as described above is selectively irradiated (exposed) with actinic rays or radiation, for example, ultraviolet rays or visible rays having a wavelength of 300 nm or more and 500 nm or less, through a mask having a predetermined pattern.

[0383] Examples of radiation sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and argon gas lasers. Examples of radiation include microwaves, infrared rays, visible light, ultraviolet rays, X-rays, gamma rays, electron beams, proton beams, neutron beams, and ion beams. The radiation dose varies depending on the composition of the photosensitive composition and the film thickness of the photosensitive layer, but is, for example, 100 mJ / cm. 2More than 10000mJ / cm 2 Radiation also includes light rays that activate the acid generator (A) to generate an acid.

[0384] After exposure, the photosensitive layer is heated (PEB) using a known method to promote diffusion of the acid, thereby changing the solubility of the photosensitive layer in a developer such as an alkaline developer in the exposed portion of the photosensitive layer.

[0385] The exposed photosensitive layer is then developed by a conventional method to dissolve and remove unnecessary portions, thereby forming a desired resist pattern or a mold for forming a plating object. In this case, an alkaline aqueous solution is used as the developer.

[0386] The photosensitive layer formed by using the above-mentioned photosensitive composition after exposure is suppressed from repelling the developer, so that, for example, the developer can be brought into contact with the entire photosensitive layer, and a resist pattern corresponding to a mask or a mold for forming a plated object can be formed over the entire area where the photosensitive layer is provided. In addition, the photosensitive layer formed by using the above-mentioned photosensitive composition after exposure is suppressed from swelling during development, and therefore, for example, the resulting resist pattern or a mold for forming a plated object is suppressed from wrinkling, dissolution of unexposed areas, and lifting or distortion caused by swelling.

[0387] Examples of the developer include aqueous solutions of alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5,4,0]-7-undecene, and 1,5-diazabicyclo[4,3,0]-5-nonane. Alternatively, an aqueous solution of the above-mentioned alkalis to which an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant has been added can be used as the developer.

[0388] The development time varies depending on the composition of the photosensitive composition, the thickness of the photosensitive layer, etc., but is usually from 1 minute to 30 minutes. The development method may be any of a puddle method, a dipping method, a puddle method, a spray development method, etc.

[0389] After the development, for example, the substrate is washed with running water for 30 to 90 seconds, and then dried using an air gun, an oven, or the like. In this manner, a resist pattern having a desired shape is formed on the metal surface of the substrate having a metal surface. In addition, in this manner, a substrate having a resist pattern on its surface can be manufactured. In this way, the photosensitive layer formed using the above-mentioned photosensitive composition is prevented from cracking, and therefore, for example, when the resulting resist pattern is used as a mold for forming a plated object, it is easy to form a plated object of a desired shape.

[0390] <Manufacturing method for plated objects> By embedding a conductor such as metal by plating in the non-resist portion (the portion removed by the developer) in the mold of the mold-attached substrate formed by the above method, it is possible to form a plated object such as a connection terminal such as a bump or a metal post, or a Cu rewiring. The plating method is not particularly limited, and various conventionally known methods can be adopted. As the plating solution, in particular, a solder plating, copper plating, gold plating, or nickel plating solution is preferably used. Finally, the remaining mold is removed using a stripping solution or the like according to a conventional method. EXAMPLES

[0391] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0392] [Examples 1 to 6 and Comparative Examples 1 to 18] In the examples and comparative examples, PAG1 and PAG2 of the following formulae were used as the acid generator (A). [ka]

[0393] In the examples and comparative examples, the following B1 to B3 and B'1 to B'16 were used as resins (resins (B)) whose solubility in alkali increases under the action of an acid. The numbers in the brackets to the right of each structural unit in the following structural formulas indicate the content (mass%) of the structural unit in the resin. The mass average molecular weight Mw and dispersity (Mw / Mn) of each resin are shown in Table 1 below.

[0394] [ka]

[0395] [ka]

[0396] [ka]

[0397] [Table 1]

[0398] In the examples and comparative examples, the following compound C1 and compound C2 of the following formula were used as the acid diffusion controller (C). C1: Adeka STAB LA-63P (a reaction product of 1,2,3,4-butanetetracarboxylic acid methyl ester with 1,2,2,6,6-pentamethyl-4-piperidinol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol) (manufactured by ADEKA Corporation) [ka]

[0399] As the alkali-soluble resin (D), the following D1 (novolak resin (condensation product of m-cresol and p-cresol) was used. The numbers in the parentheses in the structural formula below for each structural unit indicate the content (mass%) of the structural unit in the resin. The mass average molecular weight (Mw) of D1 is 8,000. [ka]

[0400] In the examples and comparative examples, a sulfur-containing compound E1 represented by the following formula was used as the sulfur-containing compound (E). [ka]

[0401] In the examples and comparative examples, the following dye F1 was used as the dye (F). F1: Curcumin

[0402] The types and parts by mass of the acid generator (A), resin (B), acid diffusion controller (C), alkali-soluble resin (D), dye (F), 0.1 part by mass of E1 as the sulfur-containing compound (E), and 0.02 part by mass of a surfactant (BYK310, manufactured by BYK-Chemie) were dissolved in 3-methoxybutyl acetate (organic solvent (S)) so that the solid content concentration was 48% by mass, to obtain the photosensitive compositions of Examples 1 to 6 and Comparative Examples 1 to 18. The solid content concentration was calculated by dividing the total mass of the resin (B), acid generator (A), acid diffusion controller (C), alkali-soluble resin (D), sulfur-containing compound (E), dye (F), and surfactant, which are components other than the organic solvent (S), by the mass of the photosensitive composition.

[0403] The photosensitive compositions thus obtained were evaluated according to the following methods, and the results are shown in Table 2. [Evaluation of resist pattern (developer repellency, swelling property and crack resistance)] The photosensitive compositions of the Examples and Comparative Examples were applied onto the copper film of a copper-sputtered silicon wafer substrate (copper film thickness: 200 nm) using a spinner, and then heated (prebaked) on a hot plate at 100°C for 150 seconds and at 150°C for 450 seconds to obtain a photosensitive layer having a thickness of 100 μm. After heating (pre-baking), the photosensitive layer was selectively exposed to Ghi rays using a mask with a 30 μm × 30 μm square pattern and a projection exposure system Prisma GHI5452 (manufactured by Ultratech) at an exposure dose 1.2 times the minimum exposure dose capable of forming a pattern of a specified size. Next, the substrate was placed on a hot plate and subjected to post-exposure baking (PEB) at 100° C. for 3 minutes. After that, a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution (developer, NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was dropped onto the exposed photosensitive layer and left at 23° C. for 60 seconds (paddle development), which was repeated six times for development. After that, the substrate was washed with running water for 60 seconds and spin-dried to obtain a substrate with a resist pattern (patterned resist film). The evaluation of developer repellency was made as follows: ◯: the developer was not repelled during development and was spread over the entire photosensitive layer, and a square pattern corresponding to the mask was formed over the entire area where the photosensitive layer was provided; x: the developer was repelled during development and could not be spread over the entire surface of the photosensitive layer, resulting in poor formation of the resist pattern (when there were areas where a square pattern was not formed, or when a square pattern was formed but had a shape significantly different from that of the mask). The swelling property was evaluated as ◯ when the photosensitive layer did not swell during development, and the resist pattern obtained showed no wrinkles, no dissolution of the unexposed areas, and no lifting or distortion.The swelling property was evaluated as × when the unexposed areas of the photosensitive layer swelled during development, and the resist pattern obtained showed wrinkles, dissolution of the unexposed areas, or lifting or distortion. Crack resistance was evaluated by observing the obtained resist pattern (square pattern). When cracks were observed at the corners of the square pattern, it was rated as ×, and when no cracks were observed at the corners of the square pattern, it was rated as ○.

[0404] [Evaluation of storage stability] The viscosity of each of the photosensitive compositions of the Examples and Comparative Examples was measured at 25° C. using an E-type viscometer immediately after preparation and after standing at 40° C. for 2 weeks. When the ratio V2 / V1 of the viscosity immediately after preparation V1 to the viscosity V2 after standing at 40° C. for two weeks was less than 1.1, it was evaluated as ○, and when it was 1.1 or more, it was evaluated as ×. The results are shown in Table 2.

[0405] According to the examples, it is clear that a chemically amplified positive-type photosensitive composition comprising an acid generator (A) that generates an acid when irradiated with actinic rays or radiation, and a resin (B) whose solubility in alkali increases due to the action of an acid, where the resin (B) is an acrylic resin (B3) that contains a structural unit represented by formula (B3-1), and having a solids concentration of 25 mass % or more and 70 mass % or less, has good storage stability, is inhibited from repelling a developer, and is capable of forming a thick-film photosensitive layer that is suppressed in swelling and has excellent crack resistance.

[0406] On the other hand, according to the comparative examples, it is found that chemically amplified positive-type photosensitive compositions that do not contain an acrylic resin (B3) containing a structural unit represented by formula (B3-1) as the resin (B) have poor storage stability or the formed photosensitive layer repels the developer, swells, or cracks.

[0407] [Table 2]

Claims

1. A chemically amplified positive-type photosensitive composition comprising: an acid generator (A) that generates an acid when irradiated with actinic rays or radiation; and a resin (B) whose solubility in an alkali increases under the action of an acid, The resin (B) contains an acrylic resin (B3), The acrylic resin (B3) is represented by the following formula (B3-1): 【Chemistry 1】 (In formula (B3-1), R ｂ０１ is -O-, R ｂ０２ and R ｂ０３ is -CO-O-R ｂ０４ and the other is a hydrogen atom; R ｂ０４ is a linear or branched alkyl group having from 1 to 20 carbon atoms, x1 and x2 are 1. The structural unit represented by The solid content is 40% by mass or more and 50% by mass or less, The content of the resin (B) is from 90 / 101.02×100 mass % to 99 mass % based on the total solid content mass of the chemically amplified positive photosensitive composition.

2. 2. The chemically amplified positive photosensitive composition according to claim 1, wherein a ratio of the mass of the structural unit represented by formula (B3-1) to the mass of the acrylic resin (B3) is 5 mass% or more and 50 mass% or less.

3. 3. The chemically amplified positive-working photosensitive composition according to claim 1 or 2, wherein V2 / V1 is less than 1.1, where V1 is the viscosity of the chemically amplified positive-working photosensitive composition measured at 25° C. using an E-type viscometer, and V2 is the viscosity of the chemically amplified positive-working photosensitive composition measured at 25° C. after standing at 40° C. for two weeks using an E-type viscometer.

4. 4. The chemically amplified positive-working photosensitive composition according to claim 1, further comprising a sulfur-containing compound (E) containing a sulfur atom capable of coordinating with a metal.

5. 5. The chemically amplified positive photosensitive composition according to claim 1, which is used for forming a mold for forming a plating shaped object.

6. A photosensitive dry film comprising a base film and a photosensitive layer formed on a surface of the base film, the photosensitive layer being made of the chemically amplified positive-type photosensitive composition according to any one of claims 1 to 5.

7. A lamination step of laminating a photosensitive layer made of the chemically amplified positive-type photosensitive composition according to any one of claims 1 to 5 on a substrate; an exposure step of position-selectively irradiating the photosensitive layer with actinic rays or radiation; and a developing step of developing the photosensitive layer after exposure.

8. A lamination step of laminating a photosensitive layer made of the chemically amplified positive-type photosensitive composition according to any one of claims 1 to 5 on a substrate having a metal surface; an exposure step of position-selectively irradiating the photosensitive layer with actinic rays or radiation; and a development step of developing the photosensitive layer after exposure to produce a mold for forming a plated object.

9. A method for producing a plated object, comprising the step of plating the mold-attached substrate produced by the method for producing a mold-attached substrate according to claim 8 to form a plated object in the mold.

Images