Photocurable compositions and methods for forming patterns

Abstract

This invention employs a photocurable composition comprising an acrylic resin (AC), an epoxy-containing compound (excluding those conforming to the acrylic resin (AC) category), and a cationic polymerization initiator. The glass transition temperature of the acrylic resin (AC) is below 0°C. This photocurable composition is characterized in that, when the viscoelasticity of its cured film is measured at a frequency of 1 Hz, the elastic modulus at 80°C is between 2.0 × 10⁶ [Pa] and 1.0 × 10⁹ [Pa].

Description

Technical Field

[0001] This invention relates to a photocurable composition and a method for patterning. This case asserts priority based on Japan Patent Application No. 2021-206081 filed on December 20, 2021, and incorporates the contents of that application into this specification. Prior Technology

[0002] As electronic components continue to improve in performance, there is a trend towards miniaturization, higher operating speeds, and higher-density wiring in semiconductor devices, leading to the development of various packaging forms. For example, hollow packaging is a type of packaging that has a hollow structure on a wiring substrate with electrodes.

[0003] The hollow package can be manufactured in the following manner. After coating a photosensitive composition onto a wiring substrate in a manner that surrounds the electrodes, the substrate is exposed through a photomask, followed by post-exposure baking (PEB) and development to form sidewalls that serve as gaps. Next, a top plate is joined to these sidewalls to create a hollow structure. Finally, molding is performed to manufacture the hollow package.

[0004] As the aforementioned photosensitive composition, for example, a photocurable adhesive material is proposed that contains a photocationic polymerizable compound and a polymerization initiator that generates cationic species by light irradiation or heating (see, for example, Patent Document 1). [Previous Technical Documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2002-97443 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] The manufacturing of electronic components requires photosensitive compositions to possess various properties. In manufacturing the aforementioned hollow package, a photosensitive composition is used as the material for the sidewalls of the spacer. The formation of the sidewalls requires the photosensitive composition to have pattern-forming properties capable of forming well-defined micro-patterns. Furthermore, the aforementioned sidewalls must also be bonded to the top plate. Furthermore, electronic components are required to be durable in the operating environment and reliable to be used stably and continuously. However, previous photocurable adhesives have not been able to simultaneously satisfy these requirements for pattern formation, reliability and adhesion, and their properties need to be further improved.

[0008] The present invention was made in view of the above circumstances, and its objective is to provide a photocurable composition with good pattern-forming properties and high reliability, which can improve the adhesion to the object when the curing film is made, and a pattern-forming method using the same. [Technical means to solve the problem]

[0009] To address the aforementioned issues, the present invention employs the following configuration.

[0010] That is, the first aspect of the present invention is a photocurable composition, characterized in that: it contains an acrylic resin (AC), an epoxy compound (A) (except for those conforming to the above-mentioned acrylic resin (AC)), and a cationic polymerization initiator (I), wherein the glass transition temperature of the acrylic resin (AC) is 0°C or less, and when the viscoelasticity of the cured film formed by curing the above-mentioned photocurable composition is measured at a frequency of 1 Hz, the elastic modulus at a temperature of 80°C is 2.0 × 10⁶ [Pa] or more and 1.0 × 10⁹ [Pa] or less.

[0011] The second aspect of the present invention is a pattern forming method, characterized by comprising the following steps: forming a photocurable film on a support using the photocurable composition of the first aspect described above; exposing the photocurable film to light; and developing the exposed photocurable film using a developer containing an organic solvent to form a negative pattern. [Effects of the Invention]

[0012] According to the present invention, a photocurable composition with good pattern-forming properties and high reliability, which can improve the adhesion to the object when the curing film is made, and a pattern-forming method using the same are provided. Implementation

[0013] In this specification and the scope of this patent application, the term "aliphatic" is a concept relative to aromatic, and is defined as a base that does not have aromatic properties, a compound that does not have aromatic properties, etc. Unless otherwise specified, "alkyl" refers to compounds containing monovalent saturated hydrocarbon groups that are straight-chain, branched, or cyclic. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, "alkyl" refers to compounds containing straight-chain, branched-chain, and cyclic divalent saturated hydrocarbon groups. "Halogenated alkyl" refers to an alkyl group in which some or all of the hydrogen atoms are replaced by halogen atoms. Examples of halogen atoms include: fluorine, chlorine, bromine, and iodine. "Fluorinated alkyl" refers to an alkyl group in which some or all of the hydrogen atoms are replaced by fluorine atoms. The term "structural unit" refers to the monomer unit that makes up a polymer compound (resin, polymer, copolymer). When described as "may have substituents", it includes the following two cases: replacing a hydrogen atom with a monovalent group (-H) and replacing a methylene group with a divalent group (-CH 2-). "Exposure" generally refers to exposure to radiation.

[0014] (Photocurable composition) The photocurable composition of this embodiment contains: an acrylic resin (AC), an epoxy compound (A) (except for those conforming to the above-mentioned acrylic resin (AC)), and a cationic polymerization initiator (I). Hereinafter, acrylic resin (AC), epoxy-containing compound (A), and cationic polymerization initiator (I) will be referred to as component (AC), component (A), and component (I), respectively.

[0015] If a photocurable film is formed using this photocurable composition, and the film is selectively exposed, the cationic portion of component (I) decomposes to produce acid in the exposed portion of the film. Through the action of this acid, the epoxy groups in component (A) undergo ring-opening polymerization, reducing the solubility of component (A) in a developer containing organic solvents. Conversely, in the unexposed portion of the photocurable film, the solubility of component (A) in a developer containing organic solvents remains unchanged. Therefore, a difference in solubility in a developer containing organic solvents appears between the exposed and unexposed portions of the photocurable film. Thus, if the photocurable film is developed using a developer containing organic solvents, the unexposed portion is dissolved and removed, forming a negative pattern.

[0016] <Acrylic Resin (AC)> The acrylic resin (AC) contained in the photocurable composition of this embodiment has a glass transition temperature of 0°C or less.

[0017] The term "acrylic resin (AC)" refers to polymers produced by polymerization of at least acrylate monomers. The hydrogen atom bonded to the α-carbon atom in "acrylate" can be replaced by a substituent. The substituent (R αx) that replaces the hydrogen atom bonded to the α-carbon atom can be an atom or group other than the hydrogen atom. Furthermore, unless otherwise specified, the α-carbon atom in acrylate refers to the carbon atom bonded to the carbonyl group of acrylic acid. Examples of substituents (R αx) include alkyl groups with 1 to 5 carbon atoms, halogen atoms, or alkyl halogenates with 1 to 5 carbon atoms.

[0018] The glass transition temperature Tg of acrylic resins is calculated using the following formula (Fox formula). 1 / (Tg+273) ={W1 / (Tg1+273)+W2 / (Tg2+273)+···} / 100 Tg: Glass transition temperature (°C) of copolymers of acrylic resins. Tg1: Glass transition temperature (°C) of homopolymers containing repeating structural units (1) derived from monomer (1). Tg2: Glass transition temperature (°C) of homopolymers containing repeating structural units (2) derived from monomer (2). W1: The ratio (mass %) of the structural unit (1) constituting the acrylic resin. W2: The ratio (mass%) of the structural unit (2) constituting the acrylic resin. W1 + W2 + ... = 100

[0019] The glass transition temperatures of the homopolymers are based on values ​​disclosed in the homepage of KTR Corporation (www.kaji-tr.com), the "Polymer Materials Handbook" (edited by the Polymer Society, Corona Corporation, first edition, published February 20, 1973), the acrylic product catalog of Kyoei Chemical Co., Ltd., and the "Polymer Data Handbook: Fundamentals" (edited by the Polymer Society, Peifengkan, published January 30, 1986).

[0020] For example, the glass transition temperature Tg (°C) of an acrylic resin, which is a copolymer of structural units derived from 2-methoxyethyl acrylate and structural units derived from n-butyl acrylate, can be calculated as follows. The monomer (1) is 2-methoxyethyl acrylate. The glass transition temperature of the homopolymer containing repeating structural units (1) derived from the monomer (1) is -50°C, and the ratio of structural units (1) is set to 73 by mass. Monomer (2) is n-butyl acrylate. The glass transition temperature of the homopolymer containing repeating structural units (2) derived from monomer (2) is -56°C, and the ratio of structural units (2) is set to 27 by mass. The glass transition temperature Tg (°C) of the acrylic resin, which is a copolymer of structural unit (1) and structural unit (2), is calculated by the following formula. 1 / (Tg+273) ={73 / (-50+273)+27 / (-56+273)} / 100 Tg≒-52℃

[0021] The glass transition temperature (Tg) of the (AC) composition is below 0°C, preferably above -100°C and below 0°C, more preferably above -75°C and below -5°C, further preferably above -65°C and below -10°C, and even more preferably above -55°C and below -15°C. If the glass transition temperature (Tg) of the (AC) composition is below the upper limit of the above range, the adhesion between the hardened film and the object can be improved, and the reliability is also enhanced. On the other hand, if it is above the lower limit of the above range, the strength of the hardened film increases, and the pattern structure is less prone to deformation. Furthermore, the lithography properties during pattern formation are improved.

[0022] The glass transition temperature Tg of (AC) composition can be controlled by selecting the type of structural unit constituting (AC) composition or adjusting the content ratio of the structural unit.

[0023] (AC) The component only needs to be a polymer generated by polymerization of at least acrylate monomers and have a glass transition temperature of 0°C or below. The polymer used in this embodiment is preferably a structural unit (ac1) derived from an acrylic monomer containing epoxy groups. By having structural units (ac1), the strength of the hardened film is increased, and the pattern structure is less prone to deformation. Furthermore, the photolithography properties during pattern formation are improved. The term "epoxy-containing acrylic monomers" refers to acrylates whose side chains contain epoxy groups. Furthermore, the polymer in this embodiment may also be a structural unit (ac2) other than the aforementioned structural unit (ac1).

[0024] ≪Structural Unit (ac1)≫ The structural unit (ac1) is a structural unit derived from an acrylic monomer containing an epoxy group. The term "structural unit derived from acrylic monomers containing epoxy groups" refers to a structural unit formed by breaking the ethylene double bonds of acrylic monomers containing epoxy groups.

[0025] As a structural unit (ac1), examples include structural units whose side chains contain epoxy groups. The term "epoxy group" mentioned here is not particularly limited and can be exemplified by: groups containing only epoxy groups; groups containing only alicyclic epoxy groups; and groups containing epoxy groups or alicyclic epoxy groups and divalent linkages.

[0026] The term "alicyclic epoxy group" refers to an alicyclic group that has an oxacyclopropane structure as a 3-membered cyclic ether. Specifically, it refers to a group that has both an alicyclic group and an oxacyclopropane structure. The alicyclic group, which forms the basic skeleton of the alicyclic epoxy group, can be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic groups include noryl, isoyl, tricyclic nonyl, tricyclic decyl, and tetracyclic dodecyl. Furthermore, the hydrogen atoms in these alicyclic groups can be substituted with alkyl, alkoxy, or hydroxyl groups. In the case of a group containing an epoxy group or an alicyclic epoxy group and a divalent linker, it is preferable that the epoxy group or the alicyclic epoxy group is bonded via a divalent linker that is bonded to an oxygen atom (-O-).

[0027] Here, there is no particular limitation on the divalent linker. Examples of suitable divalent linkers include: divalent hydrocarbon groups with substituents, divalent linkers containing heteroatoms, etc.

[0028] Regarding divalent hydrocarbon groups that can have substituents: The divalent hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. In divalent hydrocarbon groups, aliphatic hydrocarbon groups can be saturated or unsaturated, but saturation is generally preferred. More specifically, examples of aliphatic hydrocarbon groups include: straight-chain or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing rings in their structure.

[0029] The number of carbon atoms in the aforementioned straight-chain aliphatic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3. As a straight-chain aliphatic hydrocarbon group, it is preferably a straight-chain alkyl group, specifically, examples include: methylene [-CH 2-], ethyl [-(CH 2) 2-], trimethylene [-(CH 2) 3-], tetramethylene [-(CH 2) 4-], pentamethylene [-(CH 2) 5-], etc. The number of carbon atoms in the aforementioned branched aliphatic hydrocarbon group is preferably 2 to 10, more preferably 2 to 6, and even more preferably 2 to 4, with 2 or 3 being the most desirable. As a branched aliphatic hydrocarbon group, it is preferably a branched alkyl group. Specifically, examples include: alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethyl groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyltrimethylammonium groups such as -CH(CH3)CH2CH2CH2- and -CH2CH2CH2-. 2CH(CH 3)CH 2CH 2-alkyltetramethylene alkyl alkylene ...

[0030] Examples of aliphatic hydrocarbon groups containing rings in the above-described structure include: alicyclic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups with an alicyclic hydrocarbon group bonded to the end of a straight-chain or branched aliphatic hydrocarbon group, and groups with an alicyclic hydrocarbon group inserted into a straight-chain or branched aliphatic hydrocarbon group. Examples of the same straight-chain or branched aliphatic hydrocarbon groups as described above can also be cited. The number of carbon atoms in the aforementioned alicyclic hydrocarbon group is preferably 3 to 20, and more preferably 3 to 12. The aforementioned alicyclic hydrocarbon group can be a polycyclic group or a monocyclic group. As a monocyclic alicyclic hydrocarbon group, it is preferably a group obtained by removing two hydrogen atoms from a monocyclic alkane. As for the monocyclic alkane, it is preferably one with 3 to 6 carbon atoms; examples include cyclopentane and cyclohexane. The alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycyclic alkane. The polycyclic alkane is preferably one with 7 to 12 carbon atoms. Examples of such polycyclic alkane include adamantane, northane, isothane, tricyclodecane, and tetracyclododecane.

[0031] The aromatic hydrocarbon group in the divalent hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system with (4n+2) π electrons, and can be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and even more preferably 6 to 12. Examples of aromatic rings include: aromatic hydrocarbon rings of benzene, naphthalene, anthracene, phenanthrene, etc.; and aromatic heterocycles in which some carbon atoms constituting the above aromatic hydrocarbon rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include: oxygen atoms, sulfur atoms, nitrogen atoms, etc. Examples of aromatic heterocycles include: pyridine rings, thiophene rings, etc. Specifically, examples of aromatic hydrocarbon groups include: groups obtained by removing two hydrogen atoms from the aforementioned aromatic hydrocarbon ring or aromatic heterocycle (aryl or heteroaryl); groups obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, benzo[a], etc.); and groups in which one hydrogen atom of an aryl or heteroaryl group obtained by removing one hydrogen atom from the aforementioned aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkyl group (e.g., a group obtained by further removing one hydrogen atom from an aryl group in arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.). The number of carbon atoms in the alkyl group bonded to the aforementioned aryl or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and especially preferably 1.

[0032] Divalent hydrocarbon groups can have substituents. The straight-chain or branched aliphatic hydrocarbon group, which is a divalent hydrocarbon group, may have substituents or no substituents. Examples of such substituents include: fluorine atoms, fluorinated alkyl groups with 1 to 5 carbon atoms substituted with fluorine atoms, carbonyl groups, etc.

[0033] Alicyclic hydrocarbon groups, which are divalent hydrocarbon groups containing rings, may or may not have substituents. Examples of such substituents include: alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the above-mentioned substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably methyl, ethyl, propyl, n-butyl, or tributyl. The alkoxy group used as the above-mentioned substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, or tributoxy, with methoxy and ethoxy being the most preferred. Examples of halogen atoms that can be used as substituents include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred. Examples of alkyl halogens that can be used as substituents include those in which some or all of the hydrogen atoms of the alkyl group are replaced by the halogen atom group. A portion of the carbon atom constituting the ring structure of an alicyclic hydrocarbon group may be substituted by a substituent containing a heteroatom. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0034] The hydrogen atom in an aromatic hydrocarbon group, which is a divalent hydrocarbon group, can be replaced by a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group can be replaced by a substituent. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group used as the above-mentioned substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably methyl, ethyl, propyl, n-butyl, or tributyl. Regarding the alkoxy, halogen atom, and alkyl halide that are the above-mentioned substituents, examples can be given of substituents that replace the hydrogen atoms of the above-mentioned alicyclic hydrocarbon groups.

[0035] Regarding divalent linkages containing heteroatoms: The heteroatoms in a divalent bonding group containing heteroatoms are atoms other than carbon and hydrogen atoms, such as oxygen, nitrogen, sulfur, and halogen atoms.

[0036] Among the divalent linkages containing heteroatoms, preferred linkages include: -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-; -C(=O)-NH-, -NH-, -NH-C(=O)-O-, -NH-C(=NH)- (H can be substituted by alkyl, acetyl, or other substituents); -S-, -S(=O)2-, -S(=O)2-O-, general formula -Y21-OY22-, -Y21-O-, -Y21-C(=O)-O-, -C(=O)-OY21-, -[Y21-C(=O)-O]m''-Y22- or -Y21-OC(=O)-Y22- [where Y21 and Y21 are the bases represented by the formulas]. 22 are each independently divalent hydrocarbon groups that can have substituents, O is an oxygen atom, m'' is an integer from 0 to 3, etc. When the divalent linker containing the heteroatom is -C(=O)-NH-, -NH-, -NH-C(=O)-O-, or -NH-C(=NH)-, the H may be substituted by a substituent such as an alkyl or acetyl group. The number of carbon atoms in the substituent (alkyl, acetyl, etc.) is preferably 1 to 10, more preferably 1 to 8, and even more preferably 1 to 5. In formulas -Y 21-OY 22-, -Y 21-O-, -Y 21-C(=O)-O-, -C(=O)-OY 21-, -[Y 21-C(=O)-O] m''-Y 22- or -Y 21-OC(=O)-Y 22-, Y 21 and Y 22 are each independently a divalent hydrocarbon group that can have substituents. Examples of such divalent hydrocarbon groups are those identical to the "divalent hydrocarbon groups that can have substituents" exemplified in the above description of divalent linking groups. Y21 is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkyl group, and even more preferably a straight-chain alkyl group with 1 to 5 carbon atoms, especially methylene or ethyl group. Y22 is preferably a straight-chain or branched aliphatic hydrocarbon group, more preferably methylene, ethyl, or alkylmethylene. The alkyl group in the alkylmethylene group is preferably a straight-chain alkyl group with 1 to 5 carbon atoms, more preferably a straight-chain alkyl group with 1 to 3 carbon atoms, and most preferably methyl. In the basis represented by the formula -[Y 21-C(=O)-O] m''-Y 22-, m'' is an integer from 0 to 3, preferably an integer from 0 to 2, more preferably 0 or 1, and most preferably 1. That is, as the basis represented by the formula -[Y 21-C(=O)-O] m''-Y 22-, it is more preferably the basis represented by the formula -Y 21-C(=O)-OY 22-. Among them, it is more preferably the basis represented by the formula -(CH 2) a'-C(=O)-O-(CH 2) b'-. In this formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, and further preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, and further preferably 1 or 2, and most preferably 1.

[0037] Among them, the epoxy group is preferably glycidyl group.

[0038] As a structural unit (ac1), for example, the units containing epoxy groups represented by the following general formulas (a1-1) to (a1-2) can be cited.

[0039] [Chemistry 1] [In the formula, R is a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, or a haloalkyl group with 1 to 5 carbon atoms. Va 41 is a divalent hydrocarbon group that may have substituents. na 41 is an integer from 0 to 2. Ra 41 and Ra 42 are respectively epoxy groups. na 42 is 0 or 1. Wa 41 is a (na 43+1) valent aliphatic hydrocarbon group. na 43 is an integer from 1 to 3.]

[0040] In the above formula (a1-1), the alkyl group with 1 to 5 carbon atoms in R is preferably straight-chain or branched. Specifically, examples include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tributyl, pentyl, isopentyl, neopentyl, etc. In R, the alkyl halide with 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the aforementioned alkyl group with 1 to 5 carbon atoms are replaced by halogen atoms. Examples of such halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., with fluorine atoms being particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. For industrial availability, it is more preferably a hydrogen atom or a methyl group.

[0041] In the above formula (a1-1), Va 41 is a divalent hydrocarbon group that can have substituents, and examples can be given of the same divalent hydrocarbon groups that can have substituents as described in the "groups containing epoxy groups" section above. Of the above, the hydrocarbon group of Va 41 is preferably an aliphatic hydrocarbon group, more preferably a straight-chain or branched aliphatic hydrocarbon group, and even more preferably a straight-chain aliphatic hydrocarbon group, especially a straight-chain alkyl group.

[0042] In the above formula (a1-1), na 41 is an integer from 0 to 2, preferably 0 or 1.

[0043] In the above formulas (a1-1) and (a1-2), Ra41 and Ra42 are epoxy groups, the same as the above "epoxy groups", wherein glycidyl groups are preferred.

[0044] In the above formula (a1-2), the (na 43+1) valence aliphatic hydrocarbon group in Wa 41 refers to a hydrocarbon group that does not have aromaticity. It can be saturated or unsaturated, but saturation is usually preferred. Examples of the aforementioned aliphatic hydrocarbon groups include: straight-chain or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing rings in their structure, or groups formed by combining straight-chain or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing rings in their structure.

[0045] In the above formula (a1-2), na 43 is an integer from 1 to 3, preferably 1 or 2.

[0046] The following are specific examples of the structural units represented by the above formulas (a1-1) or (a1-2). In the following formula, Rα represents a hydrogen atom, a methyl group, or a trifluoromethyl group. Ra51 represents a divalent hydrocarbon group with 1 to 8 carbon atoms. Ra52 represents a divalent hydrocarbon group with 1 to 20 carbon atoms. Ra53 represents a hydrogen atom or a methyl group. na51 is an integer from 0 to 10. Ra51, Ra52, and Ra53 can be the same or different from each other.

[0047] [Chemistry 2]

[0048] [Chemistry 3]

[0049] [Chemistry 4]

[0050] [Chemistry 5]

[0051] The structural unit (ac1) of the (AC) component can be one or more. As a structural unit (ac1), it is preferably a unit containing epoxy groups as represented by the above general formula (a1-1).

[0052] When the (AC) component has a structural unit (ac1), the content ratio of the structural unit (ac1) relative to the total (100 mass%) of all structural units constituting the (AC) component is, for example, more than 0 mass% and less than 50 mass%, preferably 0.05 mass% to 40 mass%, more preferably 0.05 mass% to 20 mass%, further preferably 0.10 mass% to 10 mass%, and even more preferably 0.20 mass% to 5 mass%. If the content ratio of structural unit (ac1) exceeds the lower limit of the above range, the strength of the hardened film increases, and the pattern structure is less prone to deformation. Furthermore, the photolithography properties during pattern formation are improved. Consequently, the resin pattern exhibits increased resistance to chemicals used in the chemical treatment steps during electronic component manufacturing. On the other hand, if the upper limit of the above range is not reached, the adhesion between the hardened film and the target object is improved, and reliability is enhanced.

[0053] ≪Structural Unit (ac2)≫ Structural unit (ac2) is a structural unit of the constituent (AC) components other than the aforementioned structural unit (ac1). As a structural unit (ac2), it is acceptable as long as the glass transition temperature of the (AC) component is below 0°C. Examples include: structural units derived from acrylates other than acrylic monomers containing epoxy groups, structural units derived from acrylic acid, and structural units derived from other polymeric compounds.

[0054] The hydrogen atom bonded to the α-carbon atom of the "acrylate" and "acrylic acid" mentioned here can be substituted by a substituent. Examples of substituents (R αx) that substitute for the hydrogen atom bonded to the α-carbon atom include alkyl groups with 1 to 5 carbon atoms, halogen atoms, or alkyl halides with 1 to 5 carbon atoms.

[0055] Monomers that serve as the source of the structural unit (ac2) can be exemplified as follows: alkyl methacrylates such as 2-ethylhexyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, n-butyl methacrylate, isobutyl methacrylate, ethyl methacrylate, and methyl methacrylate; hydroxyalkyl methacrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate; alkoxyalkyl methacrylates such as 2-methoxyethyl acrylate and 2-methoxyethyl methacrylate; monocarboxylic acids such as acrylic acid, methacrylic acid, and butenoic acid; dicarboxylic acids such as maleic acid, trans-butenoic acid, and itconic acid; 2-methacryloyl ethyl succinate, 2-methacryloyl ethyl maleic acid, and phthalic acid. Methacrylic acid derivatives containing carboxyl or ester groups, such as methyl methacrylate and 2-methyl methacrylate hexahydrophthalic acid; aryl esters of (meth)acrylates, such as phenyl acrylate, benzyl acrylate, phenyl methacrylate, and benzyl methacrylate; dicarboxylic acid diesters, such as diethyl maleate and dibutyl transbutenedate; aromatic compounds containing vinyl groups, such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene; aliphatic compounds containing vinyl groups, such as vinyl acetate; conjugated dienes, such as butadiene and isoprene; polymeric compounds containing nitrile groups, such as acrylonitrile and methacrylonitrile; chlorine-containing polymeric compounds, such as vinyl chloride and vinylidene chloride; polymeric compounds containing amide groups, such as acrylamide and methacrylamide. Furthermore, the expression "(meth)acrylic acid" means either or both of acrylic acid and methacrylic acid.

[0056] The structural unit (ac2) of the (AC) component can be one or more. The preferred monomers for the structural unit (ac2) are alkyl (meth)acrylates, hydroxyalkyl (meth)acrylates, and alkoxyalkyl (meth)acrylates. In alkyl methacrylates, the number of carbon atoms in the alkyl group of the alkyl ester is preferably 1 to 5. In (meth)acrylate hydroxyalkyl esters, the number of carbon atoms in the alkyl group of the hydroxyalkyl ester portion is preferably 1 to 5. In (meth)acrylate alkoxyalkyl esters, the alkoxy group of the alkoxyalkyl ester portion preferably has 1 to 3 carbon atoms, and the alkyl group preferably has 1 to 5 carbon atoms.

[0057] When the (AC) component has a structural unit (ac2), the content ratio of the structural unit (ac2) relative to the total (100 mass%) of all structural units constituting the (AC) component is, for example, 50 mass% or more, preferably 60 mass% or more, more preferably 80 mass% or more, further preferably 90 mass% or more, especially 95 mass% or more, and may also be 100 mass% (i.e., a polymer containing a repeating structure of one or more structural units (ac2)). When the (AC) component has structural unit (ac1) and structural unit (ac2), the content ratio of the structural unit (ac2) relative to the total (100% by mass) of all structural units constituting the (AC) component is, for example, 50% by mass or more, preferably 60% by mass or more and 99.95% by mass or less, more preferably 80% by mass or more and 99.95% by mass or less, further preferably 90% by mass or more and 99.90% by mass or less, and even more preferably 95% by mass or more and 99.80% by mass or less. If the content ratio of structural unit (ac2) is above the lower limit of the above range, the adhesion between the hardened film and the object can be improved, and the reliability is also enhanced. On the other hand, if it is below the upper limit of the above range, the strength of the hardened film increases, and the pattern structure is less prone to deformation. Furthermore, the lithography properties during pattern formation are improved.

[0058] The acrylic resin (AC) contained in the photocurable composition of this embodiment has a glass transition temperature of 0°C or below. It can be used alone or in combination with two or more. Of the (AC) component, the percentage of structural units derived from "acrylate" is preferably 50% or more, more preferably 80% or more, and even more preferably 90% or more, or 100% by mass, relative to the total (100% by mass) of all structural units constituting the (AC) component. Examples of preferred (AC) components include: copolymers having structural units (ac1) and other structural units (ac2) with a glass transition temperature of 0°C or below; and polymers having only one or more structural units (ac2) with a glass transition temperature of 0°C or below.

[0059] Examples of preferred copolymers having structural unit (ac1) and other structural units (ac2) include: copolymers having structural unit (ac1) and structural units derived from alkyl methacrylates; copolymers having structural unit (ac1) and structural units derived from hydroxyalkyl methacrylates; and copolymers having structural unit (ac1) and structural units derived from alkoxyalkyl methacrylates. Furthermore, examples of copolymers having structural units (ac1) and other structural units (ac2) include: copolymers having structural units (ac1), structural units derived from (meth)acrylate alkoxyalkyl esters, and structural units derived from (meth)acrylate alkyl esters; copolymers having structural units (ac1), structural units derived from (meth)acrylate alkoxyalkyl esters, and structural units derived from (meth)acrylate hydroxyalkyl esters; and copolymers having structural units (ac1), structural units derived from (meth)acrylate hydroxyalkyl esters, and structural units derived from (meth)acrylate alkyl esters.

[0060] For example, the following can be cited: In a copolymer having a structural unit (ac1) and other structural units (ac2), relative to the total (100% by mass) of all structural units constituting the copolymer, the content of structural unit (ac1) is more than 0% by mass and less than 5% by mass, the content of structural units derived from alkoxyalkyl methacrylate is more than 30% by mass and less than 99% by mass, the content of structural units derived from hydroxyalkyl methacrylate is more than 0.5% by mass and less than 5% by mass, and the content of structural units derived from alkyl methacrylate is more than 20% by mass and less than 70% by mass.

[0061] Examples of polymers having only structural unit (ac2) include: copolymers having structural units derived from alkoxyalkyl methacrylate and structural units derived from alkyl methacrylate; copolymers having structural units derived from hydroxyalkyl methacrylate and structural units derived from alkyl methacrylate; and copolymers having structural units derived from alkoxyalkyl methacrylate and structural units derived from hydroxyalkyl methacrylate.

[0062] For example, the following can be cited: in a polymer having only structural unit (ac2), relative to the total (100% by mass) of all structural units constituting the copolymer, the content of structural units derived from alkoxyalkyl methacrylate is 30% by mass or more and 99% by mass or less, the content of structural units derived from hydroxyalkyl methacrylate is 0.5% by mass or more and 5% by mass or less, and the content of structural units derived from alkyl methacrylate is 20% by mass or more and 80% by mass or less.

[0063] The (AC) component can be manufactured by dissolving the source monomers of structural unit (ac1) and structural unit (ac2), or the source monomers of structural unit (ac2) in a polymerization solvent, and adding free radical polymerization initiators such as azobisisobutyronitrile (AIBN) and dimethyl azobisisobutyrate (e.g., V-601) to the solvent for polymerization.

[0064] The weight-average molecular weight (Mw) of the (AC) component (based on the standard polystyrene conversion standard measured by gel permeation chromatography GPC) is not particularly limited, but is preferably 20,000 to 400,000, more preferably 50,000 to 380,000, and even more preferably 100,000 to 360,000. The dispersion (Mw / Mn) of the (AC) component is not particularly limited, but is preferably 1.0 to 3.0, more preferably 1.0 to 2.5, and even more preferably 1.0 to 2.0. Mn represents the number average molecular weight.

[0065] In the photocurable composition of this embodiment, the content of component (AC) is preferably 1 to 150 parts by mass relative to 100 parts by mass of the following epoxy-containing compound (A), more preferably 5 to 100 parts by mass, further preferably 10 to 75 parts by mass, and even more preferably 10 to 50 parts by mass.

[0066] In the photocurable composition of this embodiment, the content of (AC) component is preferably 1 to 60% by mass, more preferably 3 to 50% by mass, further preferably 5 to 40% by mass, and even more preferably 5 to 30% by mass, relative to the total solid content (100% by mass) of the photocurable composition.

[0067] <Epoxy-containing compound (A)> As an example of the epoxy-containing compound (A) contained in the photocurable composition of this embodiment, a compound having epoxy groups in one molecule sufficient to form a negative pattern by exposure can be cited. Examples of component (A) include: phenolic varnish-type epoxy resin (hereinafter also referred to as "(A1) component"), bisphenol type epoxy resin (hereinafter also referred to as "(A2) component"), aliphatic epoxy resin, etc. The above-mentioned ingredient (A) can be used alone or in combination with two or more ingredients. Of which, component (A) does not include those conforming to the above acrylic resins (AC).

[0068] ≪Phenolic varnish type epoxy resin≫ As a phenolic varnish-type epoxy resin ((A1) component), the epoxy resin represented by the following general formula (anv0) is preferably exemplified.

[0069] [Chemistry 6] [In the formula, Rp1 and Rp2 are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Multiple Rp1s may be the same or different. Multiple Rp2s may be the same or different. n1 is an integer from 1 to 5. REP is an epoxy group. Multiple REPs may be the same or different.]

[0070] In the above formula (anv0), the alkyl groups of Rp1 and Rp2, having 1 to 5 carbon atoms, are, for example, straight-chain, branched, or cyclic alkyl groups having 1 to 5 carbon atoms. Examples of straight-chain or branched alkyl groups include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tributyl, pentyl, isopentyl, neopentyl, etc. Examples of cyclic alkyl groups include: cyclobutyl, cyclopentyl, etc. Among them, Rp1 and Rp2 are preferably hydrogen atoms or straight-chain or branched alkyl groups, more preferably hydrogen atoms or straight-chain alkyl groups, and even more preferably hydrogen atoms or methyl groups. In equation (anv0), the complex numbers Rp1 can be the same or different. The complex numbers Rp2 can be the same or different.

[0071] In the above formula (anv0), n1 is an integer from 1 to 5, preferably 2 or 3, and even more preferably 2.

[0072] In the above formula (anv0), R EP is a group containing an epoxy group. There are no particular limitations on the epoxy group of R EP. Examples include: groups containing only epoxy groups; groups containing only alicyclic epoxy groups; and groups containing epoxy groups or alicyclic epoxy groups and divalent linkages. The explanation regarding the epoxy group of R EP is the same as the related explanation of "epoxy group" above. Among them, the epoxy group in R EP is preferably a glycidyl group.

[0073] Furthermore, as a component (A1), resins having the structural units represented by the following general formula (anv1) can also be preferred examples.

[0074] [Chemistry 7] [In the formula, REP is an epoxy group. Ra22 and Ra23 are independently hydrogen atoms, alkyl groups with 1 to 5 carbon atoms, or halogen atoms, respectively.]

[0075] In the above formula (anv1), the alkyl groups with 1 to 5 carbon atoms in Ra22 and Ra23 are the same as the alkyl groups with 1 to 5 carbon atoms in Rp1 and Rp2 in the above formula (anv0). The halogen atoms of Ra22 and Ra23 are preferably chlorine or bromine atoms. In the above formula (anv1), REP is the same as REP in the above formula (anv0), and preferably glycidyl group.

[0076] The following are specific examples of the structural unit represented by the above formula (anv1).

[0077] [Chemistry 8]

[0078] (A1) Component may be a resin containing only the above-mentioned structural unit (anv1), or it may be a resin containing structural unit (anv1) and other structural units. Other structural units can be exemplified by the structural units represented by the following general formulas (anv2) to (anv3).

[0079] [Chemistry 9] [In the formula, Ra24 is a hydrocarbon group that may have substituents. Ra25~Ra26, Ra28~Ra30 are each independently a hydrogen atom, an alkyl group with 1~5 carbon atoms, or a halogen atom. Ra27 is a group containing an epoxy group or a hydrocarbon group that may have substituents.]

[0080] In the above formula (anv2), Ra24 is a hydrocarbon group that may have substituents. Examples of hydrocarbon groups that may have substituents include: straight-chain or branched alkyl groups, or cyclic hydrocarbon groups. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, examples include methyl, ethyl, n-propyl, n-butyl, and n-pentyl. Among these, methyl, ethyl, or n-butyl is preferred, and methyl or ethyl is even more preferred.

[0081] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specifically, examples include: isopropyl, isobutyl, tributyl, isopentyl, neopentyl, 1,1-diethylpropyl, 2,2-dimethylbutyl, etc., with isopropyl being the most preferred.

[0082] When Ra24 is a cyclic hydrocarbon group, the hydrocarbon group can be an aliphatic hydrocarbon group or an aromatic hydrocarbon group; it can also be a polycyclic group or a monocyclic group. The aliphatic hydrocarbon group that is a monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocyclic alkane. The monocyclic alkane is preferably one with 3 to 6 carbon atoms, and examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycyclic alkane. The polycyclic alkane is preferably one with 7 to 12 carbon atoms, and examples include adamantane, norethane, isoethane, tricyclodecane, tetracyclododecane, etc.

[0083] When the cyclic hydrocarbon group of Ra24 is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system with (4n+2) π electrons; it can be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5-30, more preferably 5-20, further preferably 6-15, and even more preferably 6-12. Examples of aromatic rings include: aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some carbon atoms constituting the above aromatic hydrocarbon rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include: oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include: pyridine rings and thiophene rings. Specifically, the aromatic hydrocarbon group in Ra24 can be exemplified by: a group (aryl or heteroaryl) obtained by removing one hydrogen atom from the aforementioned aromatic hydrocarbon ring or aromatic heterocycle; a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, benzoylene, etc.); or a group in which one hydrogen atom of the aforementioned aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkyl group (e.g., benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc., arylalkyl groups, etc.). The number of carbon atoms in the alkyl group bonded to the aforementioned aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and especially preferably 1.

[0084] In the above formulas (anv2) and (anv3), Ra25~Ra26 and Ra28~Ra30 are each independently a hydrogen atom, an alkyl group with 1~5 carbon atoms, or a halogen atom. The alkyl groups with 1 to 5 carbon atoms and the halogen atoms are the same as those in Ra22 and Ra23 mentioned above.

[0085] In formula (anv3) above, Ra27 is an epoxy group or a hydrocarbon group that may have substituents. The epoxy group of Ra27 is the same as REP in formula (anv0) above. The hydrocarbon group that may have substituents of Ra27 is the same as Ra24 in formula (anv2) above.

[0086] The following are specific examples of the structural units represented by the above equations (anv2) to (anv3).

[0087] [Chemistry 10]

[0088] When component (A1) has structural unit (anv1) and other structural units, the ratio of each structural unit in component (A1) is not particularly limited. Relative to the total of all structural units constituting component (A1), the total number of structural units containing epoxy groups is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, and even more preferably 30 to 70 mol.

[0089] Commercially available products containing component (A1), such as phenolic varnish-type epoxy resins, include: jER-152, jER-154, jER-157S70, jER-157S65 (manufactured by Mitsubishi Chemical Co., Ltd.); EPICLON N-740, EPICLON N-740, EPICLON N-770, EPICLON N-775, EPICLON N-660, EPICLON N-665, EPICLON N-670, EPICLON N-673, EPICLON N-680, EPICLON N-690, EPICLON N-695, EPICLON HP5000 (manufactured by DIC Co., Ltd.); YDPN and YDCN series (manufactured by Nippon Steel & Sumitomo Metal Corporation); EOCN-1020 (manufactured by Nippon Kayaku Co., Ltd.), etc.

[0090] As a component (A1), one can be used alone, or two or more can be used together. In the photocurable composition of this embodiment, the content of component (A1) is preferably 25% by mass or more, more preferably 40% by mass or more, or 50% by mass or more, or 75% by mass or more, or 90% by mass or more, or 100% by mass, relative to 100% by mass of the total amount of component (A).

[0091] ≪Bisphenol type epoxy resin≫ As a bisphenol type epoxy resin (hereinafter also referred to as "(A2) component"), any resin having a structural unit containing a bisphenol backbone is acceptable, wherein a solid bisphenol type epoxy resin is preferred. So-called solid bisphenol type epoxy resin is a resin that is solid at 25°C and has structural units containing a bisphenol backbone. (A2) The epoxy equivalent in the component is preferably 500 g / eq. or more, more preferably 550 to 1200 g / eq., and even more preferably 600 to 1000 g / eq.

[0092] As component (A2), epoxy resins represented by the following general formula (abp1) are preferably exemplified.

[0093] [Chemistry 11] [In the formula, R EP is an epoxy group. Multiple R EPs may be the same or different. Ra31 and Ra32 are independently hydrogen atoms, alkyl groups with 1 to 5 carbon atoms, or fluorinated alkyl groups with 1 to 5 carbon atoms, respectively. na31 is an integer from 1 to 50.]

[0094] In the above formula (abp1), REP is the same as REP in the above formula (anv0), and preferably glycidyl group. In the above formula (abp1), the alkyl groups with 1 to 5 carbon atoms in Ra31 and Ra32 are the same as the alkyl groups with 1 to 5 carbon atoms in Rp1 and Rp2 in the above formula (anv0). Among them, Ra31 and Ra32 are preferably hydrogen atoms or methyl groups, respectively. As fluorinated alkyl groups having 1 to 5 carbon atoms in Ra31 and Ra32, examples include alkyl groups having 1 to 5 carbon atoms in which some or all of the hydrogen atoms are replaced by fluorine atoms. In the above formula (abp1), na 31 is an integer from 1 to 50, preferably an integer from 4 to 15, and even more preferably an integer from 5 to 8.

[0095] Commercially available products that can be used as (A2) ingredients include, for example: jER-4005, jER-4007, jER-4010 (manufactured by Mitsubishi Chemical Co., Ltd.); jER-827, jER-828, jER-834, jER-1001, jER-1002, jER-1003, jER-1055, jER-1007, jER-1009, jER-1010 (manufactured by Mitsubishi Chemical Co., Ltd.); EPICLON860, EPICLON1050, EPICLON1051, EPICLON1055 (manufactured by DIC Co., Ltd.), etc.

[0096] As a component (A2), one can be used alone, or two or more can be used together. In the photocurable composition of this embodiment, the content of component (A2) is preferably 50% by mass or more, more preferably 60% by mass or more, and may also be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass, relative to 100% by mass of the total amount of component (A).

[0097] When using both component (A1) and component (A2), the ratio of component (A1) to component (A2), expressed as the mass ratio of component (A1) / (A2), is preferably 3 / 7 to 7 / 3, more preferably 4 / 6 to 6 / 4, and even more preferably 5 / 5. If the mass ratio is within the above-mentioned preferred range, the strength of the hardened film can be easily adjusted, and the effects of the present invention can be more easily obtained.

[0098] Aliphatic epoxy resins As an aliphatic epoxy resin, for example, the compound represented by the following general formula (ta1) (hereinafter also referred to as "(A3) component") can be preferably exemplified.

[0099] [Chemistry 12] [In the formula, REP is an epoxy group. Multiple REPs may be the same or different.]

[0100] In the above formula (ta1), R EP is a group containing an epoxy group, which is the same as R EP in the above formula (anv0).

[0101] Commercially available products that can be used as (A3) ingredients include, for example: TEPIC series (manufactured by Nissan Chemical Co., Ltd.), such as TEPIC, TEPIC-VL, TEPIC-PAS, TEPIC-G, TEPIC-S, TEPIC-SP, TEPIC-SS, TEPIC-HP, TEPIC-L, TEPIC-FL, TEPIC-UC, etc.; MA-DGIC, DA-MGIC, TOIC (manufactured by Shikoku Chemical Co., Ltd.), etc. As a component (A3), one can be used alone, or two or more can be used together.

[0102] Furthermore, as an aliphatic epoxy resin, examples may also be given of compounds that contain a portion of the structure represented by the following general formula (m1) (hereinafter also referred to as "(m1) component").

[0103] [Chemistry 13] [In the formula, n² is an integer from 1 to 4. * represents a bond.]

[0104] In the above formula (m1), n2 is an integer from 1 to 4, preferably an integer from 1 to 3, and even more preferably 2.

[0105] As a component (m1), examples include: a plurality of compounds in which the partial structures represented by the above general formula (m1) are bonded together via divalent linkers or single bonds. Preferably, it is a compound in which the partial structures represented by the above general formula (m1) are bonded together via divalent linkers. There are no particular limitations on the divalent linkage group here. As a preferred example, it may include: a divalent hydrocarbon group with substituents, or a divalent linkage group containing heteroatoms. Regarding the divalent hydrocarbon group that may have substituents and the divalent linked group containing heteroatoms mentioned here, they are the same as the divalent hydrocarbon group that may have substituents and the divalent linked group containing heteroatoms described in the "groups containing epoxy groups" section above. Preferably, it is a divalent linked group containing heteroatoms, more preferably a group represented by -Y 21-C(=O)-O- or -C(=O)-OY 21-. As Y 21, it is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkyl group, and even more preferably a straight-chain alkyl group with 1 to 5 carbon atoms, especially methylene or ethyl.

[0106] Commercially available products that can be used as aliphatic epoxy resins include, for example: ADEKA RESIN EP-4080S, ADEKA RESIN EP-4085S, ADEKA RESIN EP-4088S (all manufactured by ADEKA Corporation); Celloxide 2021P, Celloxide 2081, Celloxide 2083, Celloxide 2085, Celloxide 8000, Celloxide 8010, EHPE-3150, EPOLEAD PB 3600, EPOLEAD PB 4700 (all manufactured by Daicel Corporation); DENACOL EX-211L, EX-212L, EX-214L, EX-216L, EX-321L, EX-850L (all manufactured by Nagase ChemteX Corporation), etc.

[0107] In addition to the resins mentioned above, epoxy-containing compounds (A) may also be compounds represented by the following chemical formula (A4-1) and compounds represented by the following chemical formula (A4-2). Commercially available products that can be used as compounds represented by the following chemical formula (A4-1) include, for example, TECHMORE VG-3101L (manufactured by Printec Corporation). Commercially available products that can be used as compounds represented by the following chemical formula (A4-2) include, for example, Shofree (registered trademark) BATG (manufactured by Showa Denko Co., Ltd.).

[0108] [Chemistry 14]

[0109] Furthermore, examples of epoxy-containing compounds (A) include: trimethylolpropane triglycidyl ether, glyceryl triglycidyl ether; pentaerythritol tetraglycidyl ether, di-trimethylolpropane tetraglycidyl ether, diglyceryl tetraglycidyl ether, erythritol tetraglycidyl ether; xylitol pentaglycidyl ether, dipentaerythritol pentaglycidyl ether, inositol pentaglycidyl ether; dipentaerythritol hexaglycidyl ether, sorbitol hexaglycidyl ether, inositol hexaglycidyl ether, etc.

[0110] In the photocurable composition of this embodiment, component (A) is preferably an epoxy resin selected from the group consisting of bisphenol type epoxy resin (A2) and phenolic varnish type epoxy resin (A1). Among them, component (A) is more preferably composed of solid bisphenol type epoxy resin and component (A1), and even more preferably composed of epoxy resin represented by general formula (abp1) and epoxy resin represented by general formula (anv0); or composed of epoxy resin represented by general formula (abp1) and epoxy resin represented by general formula (anv1).

[0111] (A) The weight-average molecular weight of the polystyrene component is preferably 100~300,000, more preferably 200~200,000, and even more preferably 300~200,000. By setting this weight-average molecular weight, the strength of the formed hardened film is significantly improved.

[0112] The content of component (A) in the photocurable composition of this embodiment can be adjusted according to the thickness of the photocurable film to be formed. In the photocurable composition of this embodiment, the content of component (A) is preferably 40 to 99% by mass, more preferably 50 to 95% by mass, and even more preferably 60 to 90% by mass, relative to the total amount of solid components (100% by mass) of the photocurable composition.

[0113] In the photocurable composition of this embodiment, the mixing ratio of acrylic resin (AC) to epoxy compound (A) by mass is preferably (A) component / (AC) component = 40 / 60~95 / 5, more preferably 50 / 50~90 / 10, and even more preferably 60 / 40~90 / 10. If the mass ratio is above the lower limit of the aforementioned preferred range, the elastic modulus of the hardened film increases, the strength of the hardened film is enhanced, and the pattern structure is less prone to deformation. Furthermore, the photolithography properties during pattern formation are improved. On the other hand, if it is below the upper limit of the aforementioned preferred range, it is easier to further improve the adhesion between the hardened film and the object being formed.

[0114] <Catonic Polymerization Initiator (I)> The cationic polymerization initiator (I) contained in the photocurable composition of this embodiment is a compound that generates a cation when irradiated by active energy lines such as ultraviolet light, far ultraviolet light, KrF, ArF, excimer laser light, X-rays, and electron beams. This cation can serve as a polymerization initiator. Examples of components (I) include: onium borate salt (hereinafter also referred to as "(I1) component"), compounds represented by the following general formula (I2-1) or (I2-2) (hereinafter also referred to as "(I2) component"), and compounds represented by the following general formula (I3-1) or (I3-2) (hereinafter also referred to as "(I3) component").

[0115] ≪Boronium salts≫ Onium borate salts (I1 component) produce a relatively strong acid upon exposure. Therefore, by using photocurable compositions containing I1 component to form patterns, sufficient sensitivity can be obtained to form good patterns. Furthermore, the risk of toxicity or metal corrosion from using I1 component is low. As a component of (I1), for example, compounds represented by the following general formula (I1) can be preferably exemplified.

[0116] [Chemistry 15] [In the formula, Rb01~Rb04 are aryl or fluorine atoms that can be substituented, respectively. q is an integer greater than or equal to 1, and Qq+ is a q-valent organic cation.]

[0117] • Anion section In the above formula (I1), the number of carbon atoms in the aryl group of Rb01 to Rb04 is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and even more preferably 6 to 12. Specifically, examples include naphthyl, phenyl, anthracene, etc., with phenyl being the most readily available. The aryl group in Rb01 to Rb04 may have substituents. There are no particular limitations on the substituent, but it is preferably a halogen atom, a hydroxyl group, an alkyl group (preferably a straight-chain or branched alkyl group, preferably with 1 to 5 carbon atoms), or a haloalkyl group; more preferably a halogen atom or a haloalkyl group with 1 to 5 carbon atoms; and especially preferably a fluorine atom or a fluorinated alkyl group with 1 to 5 carbon atoms. Having a fluorine atom in the aryl group increases the polarity of the anionic portion, which is preferable. Among them, Rb01~Rb04 of formula (I1) are preferably fluorinated phenyl, and more preferably perfluorophenyl.

[0118] Examples of preferred embodiments of the anionic portion of the compound represented by formula (I1) above include: tetratetra(pentafluorophenyl)borate ([B(C6F5)4]-); tetratetra[(trifluoromethyl)phenyl]borate ([B(C6H4CF3)4]-); difluorobis(pentafluorophenyl)borate ([(C6F5)2BF2]-); trifluoro(pentafluorophenyl)borate ([(C6F5)BF3]-); tetratetra(difluorophenyl)borate ([B(C6H3F2)4]-), etc. Among them, tetra(pentafluorophenyl)borate ([B(C6F5)4]-) is particularly preferred.

[0119] • Cation section In the above formula (I1), Q q+ can preferably be represented by strontium cation, monium cation, and more preferably by organic cations represented by the following general formulas (ca-1) to (ca-5).

[0120] [Chemistry 16] [In the formula, R 201~R 207 and R 211~R 212 independently represent aryl, heteroaryl, alkyl, or alkenyl groups that may have substituents. R 201~R 203, R 206~R 207, and R 211~R 212 can also be bonded to each other to form a ring with the sulfur atom in the formula. R 208~R 209 independently represent hydrogen atoms or alkyl groups with 1 to 5 carbon atoms. R 210 is an aryl group that may have substituents, an alkyl group that may have substituents, an alkenyl group that may have substituents, or a cyclic group containing -SO 2- that may have substituents. L 201 represents -C(=O)- or -C(=O)-O-. Y 201 independently represents an aryl, alkyl, or alkenyl group. x is 1 or 2. W 201 represents a (x+1) valence linkage group.]

[0121] As for the aryl groups in R 201~R 207 and R 211~R 212, examples include unsubstituted aryl groups with 6~20 carbon atoms, with phenyl and naphthyl being preferred. As heteroaryl groups in R 201~R 207 and R 211~R 212, examples can be given of those in which a portion of the carbon atom constituting the aforementioned aryl group is replaced by a heteroatom. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of such heteroaryl groups include 9H-thiosulfate. The radical obtained by removing one hydrogen atom; as a substituted heteroaryl group, examples include 9H-thioyl group. -9-keto compounds obtained by removing one hydrogen atom, etc. The alkyl group among R 201~R 207 and R 211~R 212 is preferably a chain or cyclic alkyl group with 1~30 carbon atoms. The alkenyl group in R 201~R 207 and R 211~R 212 is preferably composed of 2~10 carbon atoms. Substituents that can be present in R 201~R 207 and R 210~R 212 include, for example: alkyl, halogen atom, haloalkyl, carbonyl, cyano, amino, side oxygen (=O), aryl, and groups represented by the following formulas (ca-r-1)~(ca-r-10).

[0122] [Chemistry 17] [In the formula, R', 201 are respectively a hydrogen atom, a cyclic group that may have substituents, a chain alkyl group that may have substituents, or a chain alkenyl group that may have substituents.]

[0123] In the above formulas (ca-r-1) to (ca-r-10), R' 201 can be a hydrogen atom, a cyclic group that may have substituents, a chain alkyl group that may have substituents, or a chain alkenyl group that may have substituents, respectively.

[0124] Cyclic groups that may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which can be an aromatic hydrocarbon group or a cyclic aliphatic hydrocarbon group. An aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromatic properties. Furthermore, the aliphatic hydrocarbon group can be saturated or unsaturated, but saturation is generally preferred.

[0125] The aromatic hydrocarbon group in R' 201 is a hydrocarbon group having an aromatic ring. The number of carbon atoms in this aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. This number of carbon atoms does not include the number of carbon atoms in the substituents. Specifically, examples of aromatic rings in R' 201 include: benzene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some carbon atoms of such aromatic rings are substituted with heteroatoms, or rings in which some hydrogen atoms of such aromatic rings or aromatic heterocycles are substituted with side oxygen groups, etc. Examples of heteroatoms in aromatic heterocycles include: oxygen atoms, sulfur atoms, nitrogen atoms, etc. As an aromatic hydrocarbon group in R' 201, examples include: groups obtained by removing one hydrogen atom from the above-mentioned aromatic ring (e.g., aryl groups such as phenyl, naphthyl, anthracene, etc.); groups in which one hydrogen atom of the above-mentioned aromatic ring is substituted with an alkyl group (e.g., arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.); groups obtained by removing one hydrogen atom from a ring in which some hydrogen atoms constituting the above-mentioned aromatic ring are substituted with a side oxygen group (e.g., anthraquinone, etc.); and groups from aromatic heterocycles (e.g., 9H-thiosulfate). 9H-sulfur The alkyl group obtained by removing one hydrogen atom from the alkyl group (such as 9-ketone). The number of carbon atoms in the above-mentioned alkyl group (alkyl chain in arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and even more preferably 1.

[0126] As a cyclic aliphatic hydrocarbon group in R' 201, examples of aliphatic hydrocarbon groups containing rings in their structure can be given. Examples of aliphatic hydrocarbon groups containing rings in this structure include: alicyclic hydrocarbon groups (groups obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), groups with an alicyclic hydrocarbon group bonded to the end of a straight-chain or branched aliphatic hydrocarbon group, and groups with an alicyclic hydrocarbon group inserted into a straight-chain or branched aliphatic hydrocarbon group. The number of carbon atoms in the aforementioned alicyclic hydrocarbon group is preferably 3 to 20, and more preferably 3 to 12. The aforementioned alicyclic hydrocarbon group can be either a polycyclic or monocyclic group. As a monocyclic alicyclic hydrocarbon group, it is preferably a group obtained by removing one or more hydrogen atoms from a monocyclic alkane. As the monocyclic alkane, it is preferably one with 3 to 6 carbon atoms; examples include cyclopentane and cyclohexane. As a polycyclic alicyclic hydrocarbon group, it is preferably a group obtained by removing one or more hydrogen atoms from a polycyclic alkane. As the polycyclic alkane, it is preferably one with 7 to 30 carbon atoms. More preferably, as the polycyclic alkane, it is adamantane, northoalkyl, isoalkyl, tricyclodecane, tetracyclododecane, etc., which have a polycyclic skeleton with a cross-linked ring system; or a cyclic group with a steroid skeleton, etc., which have a polycyclic skeleton with a condensed ring system.

[0127] Among them, the cyclic aliphatic hydrocarbon group in R' 201 is preferably a group obtained by removing one or more hydrogen atoms from a monocyclic alkane or polycyclic alkane, more preferably a group obtained by removing one hydrogen atom from a polycyclic alkane, especially adamantyl or noryl, and most preferably adamantyl.

[0128] The number of carbon atoms in the straight-chain or branched aliphatic hydrocarbon group that can bond with the alicyclic hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3. As a straight-chain aliphatic hydrocarbon group, it is preferred to be a straight-chain alkyl group, specifically, examples include: methylene [-CH 2-], ethyl [-(CH 2) 2-], trimethylene [-(CH 2) 3-], tetramethylene [-(CH 2) 4-], pentamethylene [-(CH 2) 5-], etc. As a branched aliphatic hydrocarbon group, it is preferably a branched alkyl group. Specifically, examples include: alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethyl groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyltrimethylammonium groups such as -CH(CH3)CH2CH2CH2- and -CH2CH2CH2-. 2CH(CH 3)CH 2CH 2-alkyltetramethylene alkyl alkylene ...

[0129] Chain alkyl groups that may have substituents: As a chain alkyl group of R' 201, it can be either straight-chain or branched. As a straight-chain alkyl group, the number of carbon atoms is preferably 1 to 20, more preferably 1 to 15, and most preferably 1 to 10. Specifically, examples include: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotriadecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecanyl, heptadecanyl, octadecyl, nonadecanyl, eicosyl, dodecyl, dodecyl, etc. As a branched alkyl group, the number of carbon atoms is preferably 3 to 20, more preferably 3 to 15, and most preferably 3 to 10. Specific examples include: 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, etc.

[0130] Chain alkenyl groups that may have substituents: The chain-like alkenyl group of R'201 can be either straight-chain or branched, and the number of carbon atoms is preferably 2 to 10, more preferably 2 to 5, further preferably 2 to 4, and especially preferably 3. Examples of straight-chain alkenyl groups include vinyl, allyl, and butynyl. Examples of branched alkenyl groups include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, and 2-methylpropenyl. As a chain alkenyl group, the preferred type is a straight-chain alkenyl group, more preferably a vinyl or propenyl group, and especially vinyl.

[0131] Examples of substituents in the cyclic, chain-like alkyl, or alkenyl groups of R' 201 include: alkoxy, halogen atom, haloalkyl, hydroxyl, carbonyl, nitro, amino, lateral oxy, cyclic groups in the aforementioned R' 201, alkyl carbonyl, thiophene carbonyl, etc.

[0132] R' 201 is preferably a cyclic group that may have substituents or a chain alkyl group that may have substituents.

[0133] When R 201~R 203, R 206~R 207, and R 211~R 212 are bonded to each other and form a ring together with the sulfur atom in the formula, the bonds can be formed through heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or functional groups such as carbonyl groups, -SO-, -SO 2-, -SO 3-, -COO-, -CONH-, or -N(RN)- (where RN is an alkyl group with 1 to 5 carbon atoms). As for the formed ring, the ring skeleton includes one ring containing the sulfur atom in the formula, preferably a 3 to 10-membered ring, and more preferably a 5 to 7-membered ring. Specific examples of the formed ring include: thiophene rings, thiazole rings, benzothiophene rings, thion rings, benzothiophene rings, dibenzothiophene rings, and 9H-sulfur rings. cyclic, 9-oxosulfur Rings, thiophene rings, phenanthrene rings, tetrahydrothiophene rings, tetrahydrothioranonium rings, etc.

[0134] In the above formula (ca-3), R 208 to R 209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. When they are alkyl groups, they can also bond with each other to form a ring.

[0135] In the above formula (ca-3), R 210 is an aryl group that may have a substituent, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or a cyclic group containing -SO 2- that may have a substituent. As an aryl group in R 210, examples include unsubstituted aryl groups with 6 to 20 carbon atoms, with phenyl and naphthyl being preferred. As for the alkyl group in R 210, it is preferred to be a chain or cyclic alkyl group with 1 to 30 carbon atoms. The alkenyl group in R 210 is preferably composed of 2 to 10 carbon atoms.

[0136] In formulas (ca-4) and (ca-5) above, Y 201 independently represents aryl, alkyl, or alkenyl groups, respectively. As an extended aryl group in Y 201, an example can be taken from the aryl group exemplified as an aromatic hydrocarbon group in R' 201, which is obtained by removing one hydrogen atom. As for the alkyl or alkenyl groups in Y 201, examples can be derived from the groups obtained by removing one hydrogen atom from the groups exemplified as chain alkyl or chain alkenyl groups in R' 201.

[0137] In the above equations (ca-4) and (ca-5), x is 1 or 2. W 201 is a (x+1) valence, i.e., a divalent or trivalent linker. The divalent linker in W 201 is preferably a divalent hydrocarbon group that may have substituents, and more preferably the same as the divalent hydrocarbon group that may have substituents exemplified in the "groups containing epoxy groups" above. The divalent linker in W 201 can be any of straight-chain, branched, or cyclic, but is preferably cyclic. Preferably, it is a group with two carbonyl groups combined at both ends of the aryl group, or a group containing only the aryl group. Examples of aryl groups include phenyl, naphthyl, etc., with phenyl being particularly preferred. Examples of trivalent linkers in W 201 include: groups obtained by removing one hydrogen atom from the divalent linker in W 201, and groups obtained by further bonding the divalent linker to the divalent linker. Preferably, a trivalent linker in W 201 is a group with two carbonyl groups bonded to an aryl group.

[0138] As a suitable cation represented by the above formula (ca-1), examples can be given of the cations represented by the following formulas (ca-1-1) to (ca-1-24).

[0139] [Chemistry 18]

[0140] [Chemistry 19] [In the formula, R'' 201 is a hydrogen atom or a substituent. This substituent is the same as those exemplified as substituents that R 201~R 207 and R 210~R 212 may have.]

[0141] Furthermore, the cation represented by the above formula (ca-1) is preferably the cation represented by the following general formulas (ca-1-25) to (ca-1-35).

[0142] [Chemistry 20]

[0143] [Chemistry 21] [In the formula, R'211 is an alkyl group. R hal is a hydrogen atom or a halogen atom.]

[0144] Furthermore, the cation represented by the above formula (ca-1) is preferably the cation represented by the following chemical formulas (ca-1-36) to (ca-1-48).

[0145] [Chemistry 22]

[0146] Suitable cations represented by the above formula (ca-2) include, specifically, diphenyl ciprofloxacin cation, bis(4-tert-butylphenyl) ciprofloxacin cation, etc.

[0147] As a suitable cation represented by the above formula (ca-3), examples can be given of the cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0148] [Chemistry 23]

[0149] As a suitable cation represented by the above formula (ca-4), examples can be given of the cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0150] [Chemistry 24]

[0151] Furthermore, the cation represented by the above formula (ca-5) is preferably the cation represented by the following general formulas (ca-5-1) to (ca-5-3).

[0152] [Chemistry 25] [In the formula, R' 212 is an alkyl group or a hydrogen atom. R' 211 is an alkyl group.]

[0153] In the above, the cation portion [(Q q+) 1 / q] is preferably a cation represented by the general formula (ca-1), more preferably a cation represented by formulas (ca-1-1) to (ca-1-48), and even more preferably a cation represented by formula (ca-1-25), formula (ca-1-29), formula (ca-1-35), formula (ca-1-47), or formula (ca-1-48).

[0154] The following are specific examples of suitable (I1) ingredients.

[0155] [Chemistry 26]

[0156] ≪(I2) composition≫ (I2) refers to compounds represented by the following general formula (I2-1) or (I2-2). The (I2) component produces a relatively strong acid upon exposure. Therefore, when using a photocurable composition containing the (I) component to form a pattern, sufficient sensitivity can be obtained to form a good pattern.

[0157] [Chemistry 27] [In the formula, Rb05 is a fluorinated alkyl group or a fluorine atom that may have substituents. Multiple Rb05s may be the same or different. q is an integer greater than or equal to 1, and Qq+ is a q-valent organic cation.]

[0158] [Chemistry 28] [In the formula, Rb06 is a fluorinated alkyl group or a fluorine atom that may have substituents. Multiple Rb06s may be the same or different. q is an integer greater than or equal to 1, and Qq+ is a q-valent organic cation.]

[0159] • Anion section In the above formula (I2-1), Rb05 is a fluorinated alkyl group or a fluorine atom that may have substituents. Multiple Rb05s may be the same or different from each other. The fluorinated alkyl group in Rb05 preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and even more preferably 1 to 5. Specifically, for example, some or all of the hydrogen atoms in the alkyl group having 1 to 5 carbon atoms may be replaced by a fluorine atom group. RbO5 is preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and even more preferably a fluorine atom, trifluoromethyl or pentafluoroethyl.

[0160] The anionic portion of the compound represented by formula (I2-1) is preferably represented by the following general formula (b0-2a).

[0161] [Chemistry 29] [In the formula, Rbf05 is a fluorinated alkyl group that may have substituents. nb1 is an integer from 1 to 5.]

[0162] In formula (b0-2a), the fluorinated alkyl group that may have substituents in R bf05 is the same as the fluorinated alkyl group that may have substituents exemplified in R b05 above. In equation (b0-2a), nb 1 is preferably an integer from 1 to 4, more preferably an integer from 2 to 4, and most preferably 3.

[0163] In the above formula (I2-2), Rb06 is a fluorinated alkyl group or a fluorine atom that may have substituents. Multiple Rb06s may be the same or different from each other. The fluorinated alkyl group in Rb06 preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and even more preferably 1 to 5. Specifically, for example, some or all of the hydrogen atoms in the alkyl group having 1 to 5 carbon atoms may be replaced by a fluorine atom group. RbO6 is preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and even more preferably a fluorine atom.

[0164] • Cation section In formulas (I2-1) and (I2-2), q is an integer greater than or equal to 1, and Q q+ is a q-valent organic cation. As for Q q+, examples can be given that are the same as Q q+ in the above formula (I1), among which, it is more preferably a cation represented by the general formula (ca-1), more preferably a cation represented by formulas (ca-1-1) to (ca-1-48), and even more preferably a cation represented by formula (ca-1-25), a cation represented by formula (ca-1-29), a cation represented by formula (ca-1-35), and a cation represented by formula (ca-1-47).

[0165] The following are specific examples of suitable (I2) ingredients.

[0166] [Chemistry 30]

[0167] ≪(I3)Ingredients≫ (I3) refers to compounds represented by the following general formula (I3-1) or (I3-2).

[0168] [Chemistry 31] [In the formula, Rb11~Rb12 are cyclic groups that may have substituents other than halogen atoms, chain alkyl groups that may have substituents other than halogen atoms, or chain alkenyl groups that may have substituents other than halogen atoms. m is an integer greater than or equal to 1, and Mm+ are each an m-valent organic cation.]

[0169] {(I3-1)Component} • Anion section In formula (I3-1), Rb12 can be a cyclic group having substituents other than halogen atoms, a chain alkyl group having substituents other than halogen atoms, or a chain alkenyl group having substituents other than halogen atoms. Examples of the cyclic group, chain alkyl group, and chain alkenyl group described above that do not have substituents or have substituents other than halogen atoms can be cited. Rb12 is preferably a chain alkyl group that may have substituents other than halogen atoms, or an aliphatic cyclic group that may have substituents other than halogen atoms. As a chain alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 3 to 10. As an aliphatic cyclic group, it is more preferably a group obtained by removing one or more hydrogen atoms from adamantane, northane, isothane, tricyclodecane, tetracyclododecane, etc. (which may have substituents other than halogen atoms); or a group obtained by removing one or more hydrogen atoms from camphor, etc. The hydrocarbon group of Rb12 may have substituents other than halogen atoms. Examples of such substituents are those that are the same as those that the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in Rb11 of the above formula (I3-2) may have. Here, the phrase "may have substituents other than halogen atoms" excludes not only substituents containing only halogen atoms, but also substituents containing even one halogen atom (such as fluorinated alkyl groups).

[0170] The following is a preferred example of the anionic portion of component (I3-1).

[0171] [Chemistry 32]

[0172] • Cation section In formula (I3-1), M m+ is an m-valent organic cation. As an organic cation of M m+, examples are preferably those identical to the cations represented by the above general formulas (ca-1) to (ca-5), among which the cation represented by the above general formula (ca-1) is more preferred. In particular, in terms of improving resolution or roughness characteristics, at least one of R 201, R 202, and R 203 in the above general formula (ca-1) is a strontium cation that has an organic group (aryl, heteroaryl, alkyl, or alkenyl) with 16 or more carbon atoms that may have substituents. As substituents that the above-mentioned organic groups may have, examples include: alkyl, halogen atom, alkyl halide, carbonyl, cyano, amino, side oxygen (=O), aryl, and groups represented by the above formulas (ca-r-1) to (ca-r-10). The number of carbon atoms in the above-mentioned organic group (aryl, heteroaryl, alkyl or alkenyl) is preferably 16 to 25, more preferably 16 to 20, and even more preferably 16 to 18. For example, the organic cations represented by the above formulas (ca-1-25), (ca-1-26), (ca-1-28) to (ca-1-36), (ca-1-38), (ca-1-46), and (ca-1-47) are preferred, among which the cation represented by the above formula (ca-1-29) is even more preferred.

[0173] {(I3-2)Component} • Anion section In formula (I3-2), Rb11 can be a cyclic group having substituents other than halogen atoms, a chain alkyl group having substituents other than halogen atoms, or a chain alkenyl group having substituents other than halogen atoms. Examples of cyclic groups, chain alkyl groups, and chain alkenyl groups mentioned in the description of R' 201 above are those without substituents or those with substituents other than halogen atoms.

[0174] Of these, Rb11 is preferably an aromatic hydrocarbon group having substituents other than halogen atoms, an aliphatic cyclic group having substituents other than halogen atoms, or a chain alkyl group having substituents other than halogen atoms. Examples of substituents that may be present in these groups include: hydroxyl, side oxygen, alkyl, aryl, lactone-containing cyclic group, ether bond, ester bond, or combinations thereof. When the substituents include ether or ester bonds, they can be bonded via alkyl groups. In this case, the substituents are preferably the linking groups represented by the following general formulas (y-al-1) to (y-al-7). Furthermore, in the following general formulas (y-al-1) to (y-al-7), the bond with R b11 in the above formula (I3-2) is V' 101 in the following general formulas (y-al-1) to (y-al-7).

[0175] [Chemistry 33] [In the formula, V' 101 is a single bond or an alkyl group with 1 to 5 carbon atoms. V' 102 is a divalent saturated hydrocarbon group with 1 to 30 carbon atoms.]

[0176] The divalent saturated hydrocarbon group in V' 102 is preferably an alkyl group with 1 to 30 carbon atoms, more preferably an alkyl group with 1 to 10 carbon atoms, and even more preferably an alkyl group with 1 to 5 carbon atoms.

[0177] As the alkyl groups in V' 101 and V' 102, they can be straight-chain alkyl groups or branched alkyl groups, with straight-chain alkyl groups being more preferred. Specifically, examples of alkylene groups in V' 101 and V' 102 include: methylene [-CH 2-]; alkylmethylene groups such as -CH(CH 3)-, -CH(CH 2CH 3)-, -C(CH 3) 2-, -C(CH 3)(CH 2CH 3)-, -C(CH 3)(CH 2CH 2CH 3)-, and -C(CH 2CH 3) 2-; alkylethylene groups such as -CH 2CH 2-; alkylethylene groups such as -CH(CH 3)CH 2-, -CH(CH 3)CH(CH 3)-, -C(CH 3) 2CH 2-, and -CH(CH 2CH 3)CH 2-; alkylpropylene groups such as -CH 2CH 2CH 2-; -CH(CH 3)CH 2CH 2-, and -CH 2CH(CH 3)CH 2-. 2-alkyltrimethylene; tetramethylene [-CH 2CH 2CH 2CH 2-]; -CH(CH 3)CH 2CH 2CH 2-, -CH 2CH(CH 3)CH 2CH 2- alkyltetramethylene; pentamethylene [-CH 2CH 2CH 2CH 2CH 2-] etc. Furthermore, one of the methylene groups in the aforementioned alkyl groups of V' 101 or V' 102 may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. This aliphatic cyclic group is preferably a divalent group obtained by removing one hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic or polycyclic) of R' 201, and more preferably cyclohexyl, 1,5-adamantyl, or 2,6-adamantyl.

[0178] The aromatic hydrocarbon group mentioned above is preferably phenyl or naphthyl. The aliphatic cyclic group described above is preferably a group obtained by removing one or more hydrogen atoms from polycyclic alkanes such as adamantane, northane, isothane, tricyclodecane, and tetracyclododecane. The aforementioned chain alkyl groups are preferably composed of 1 to 10 carbon atoms. Specifically, examples include straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl; and branched-chain alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl.

[0179] As Rb11, it is preferably a cyclic group that can have substituents other than halogen atoms. The following is a preferred example of the anionic portion of component (I3-2).

[0180] [Chemistry 34]

[0181] • Cation section In formula (I3-2), M m+ is an m-valent organic cation, which is the same as M m+ in formula (I3-1) above.

[0182] Furthermore, regarding the high elasticity of the resin film and its ease of forming fine structures without leaving residue, component (I) is preferably a cationic polymerization initiator that produces an acid with a pKa (acid dissociation constant) of -5 or less upon exposure. By using a cationic polymerization initiator that produces an acid with a pKa of -6 or less, and more preferably a pKa of -8 or less, higher sensitivity to exposure can be obtained. The lower limit of the pKa of the acid produced by component (I) is preferably -15 or more. By using a cationic polymerization initiator that produces an acid with a suitable pKa, high sensitivity can be easily achieved. Here, "pKa (acid dissociation constant)" is a commonly used indicator of the acid strength of the substance in question. Furthermore, the pKa values ​​in this specification are values ​​obtained at 25°C. Also, pKa values ​​can be determined using known methods. Alternatively, they can be calculated using known software such as "ACD / Labs" (trade name, manufactured by Advanced Chemistry Development Co., Ltd.).

[0183] The following are specific examples of suitable (I3) ingredients.

[0184] [Chemistry 35]

[0185] As component (I), one can be used alone, or two or more can be used together. In the photocurable composition of this embodiment, component (I) is preferably at least one of the group consisting of component (I1), component (I2) and component (I3), and more preferably at least one of the group consisting of component (I1) and component (I2).

[0186] In the photocurable composition of this embodiment, relative to the total content of components (AC) and (A) of 100 parts by mass, the content of component (I) is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and even more preferably 0.2 to 1 part by mass. (I) If the content of the component is above or below the lower limit of the aforementioned preferred range, sufficient sensitivity can be obtained, and the microlithography properties of the resist pattern can be further improved. Furthermore, the strength of the resin-cured film can be further enhanced. On the other hand, if it is below or below the upper limit of the aforementioned preferred range, the sensitivity is moderately controlled, and a well-shaped resist pattern is easily obtained.

[0187] <Any ingredient> The photocurable composition of this embodiment may also contain other components (arbitrary components) besides the above-mentioned components (AC), (A) and (I), as needed. As needed, additives with commensurability, such as metal oxides (M), sensitizers, solvents, additional resins for improving film performance, dissolution inhibitors, alkaline compounds, plasticizers, stabilizers, colorants, and anti-halo agents, may be appropriately added to the photocurable composition of this embodiment.

[0188] ≪Metal Oxides (M)≫ Regarding the ease of obtaining a hardened film with improved strength, the photocurable composition of this embodiment may also contain a metal oxide (M) (hereinafter also referred to as "(M) component") in addition to components (AC), (A), and (I). By using component (M) in combination, it is possible to form a well-shaped and high-resolution pattern. Examples of components (M) include oxides of metals such as silicon (metallic silicon), titanium, zirconium, and hafnium. Among these, oxides of silicon are preferred, and silicon dioxide is particularly preferred. The shape of component (M) is preferably particulate. As the particulate component (M), it is preferable to contain a group of particles with a volume average particle size of 5 to 40 nm, more preferably a group of particles with a volume average particle size of 5 to 30 nm, and even more preferably a group of particles with a volume average particle size of 10 to 20 nm.

[0189] ≪Sensitizer Ingredients≫ The photocurable composition of this embodiment may further contain a sensitizer component. As a sensitizer component, there are no particular limitations as long as it can absorb the energy generated by exposure and be able to transfer that energy to other substances. Specifically, as a sensitizer component, benzophenone-based photosensitizers such as p,p'-tetramethyldiaminobenzophenone, carbazole-based photosensitizers, acetophenone-based photosensitizers, naphthalene-based photosensitizers such as 1,5-dihydroxynaphthalene, phenol-based photosensitizers, anthracene-based photosensitizers such as 9-ethoxyanthracene, diacetyl, eosin, rose bengal, pyrene, phenanthrene, anthrone, and other known photosensitizers can be used.

[0190] Solvent The photocurable composition of this embodiment may further contain a solvent (hereinafter sometimes referred to as "(S) component"). Examples of (S) components include: lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl n-pentanone, methyl isopentanone, and 2-heptanone; polyols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds containing ester bonds such as 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; and monoalkyl ethers or monophenyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether of the above polyols or compounds containing ester bonds. Derivatives of polyols [preferably propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME)]; cyclic ethers such as dialkylene, or esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc.; aromatic organic solvents such as anisole, ethyl benzyl ether, tolyl methyl ether, diphenyl ether, dibenzyl ether, phenethyl ether, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, isopropyltoluene, mesitylene, etc., and dimethyl sulfoxide (DMSO), etc.

[0191] (S) Component can be used alone or in combination with two or more solvents.

[0192] When the component (S) is included, there is no particular limitation on the amount used. The concentration should be set appropriately according to the coating film thickness, based on the concentration that allows the photocurable composition to be coated on a substrate or the like without droplet formation. For example, component (S) can be used in a manner that allows the concentration of solids to be 50% by mass or more, or component (S) can be used in a manner that allows the concentration of solids to be 60% by mass or more. Alternatively, it may be in a form that is substantially free of (S) components (i.e., a form with a solid content concentration of 100% by mass).

[0193] [Elastic modulus of hardened membrane] Regarding the photocurable composition of this embodiment, when the viscoelasticity of the cured film formed by curing the photocurable composition is measured at a frequency of 1 Hz, the elastic modulus at a temperature of 80°C is 2.0 × 10⁶ [Pa] or more and 1.0 × 10⁹ [Pa] or less.

[0194] The elastic modulus of the hardened film was determined by measuring the tensile elastic modulus at 80°C when performing viscoelasticity testing on the hardened film at a frequency of 1 Hz. The hardened film was obtained by sequentially baking the photocurable composition in an oven at 60°C for 5 minutes, 70°C for 5 minutes, and 80°C for 10 minutes to form a photocurable film with a thickness of 50 μm. The film was then exposed to gamma rays, h rays, and i rays at an irradiation level sufficient to form a 100 μm pattern for each component, followed by baking at 90°C for 5 minutes to harden it. A heating rate of 1~10°C / min is preferred.

[0195] Regarding the photocurable composition of this embodiment, the elastic modulus of the cured film formed by curing the photocurable composition is 2.0×10⁶ Pa or more and 1.0×10⁹ Pa or less, preferably 2.0×10⁶ Pa or more and 8.0×10⁸ Pa or less, and even more preferably 2.5×10⁶ Pa or more and 7.5×10⁸ Pa or less. If the elastic modulus of the hardened film is above the lower limit of the aforementioned range, the hardened film has sufficient strength, and the pattern structure is not easily deformed, thus improving the structure retention. On the other hand, if it is below the upper limit of the aforementioned range, the adhesion between the hardened film and the object is easily improved.

[0196] For example, by appropriately adjusting the copolymer composition of the acrylic resin (AC), glass transition temperature, weight average molecular weight, type of epoxy-containing compound (A), and mixing ratio of acrylic resin (AC) and epoxy-containing compound (A) in the photocurable composition, the elastic modulus of the above-mentioned cured film can be controlled to be above 2.0 × 10⁶ [Pa] and below 1.0 × 10⁹ [Pa]. Appropriate adjustments to the copolymer composition of acrylic resin (AC), glass transition temperature, and mixing ratio of acrylic resin (AC) to epoxy-containing compound (A) are particularly effective for improving the elastic modulus of the aforementioned cured film.

[0197] The photocurable composition of this embodiment has a viscosity of 10~5000 mPa·s at 23°C, or it can be 30~3000 mPa·s, or it can be 50~2000 mPa·s.

[0198] The photocurable composition of this embodiment described above contains an acrylic resin (AC), an epoxy-containing compound (A), and a cationic polymerization initiator (I). The (AC) component is selected from those with a glass transition temperature of 0°C or lower. This modifies the cured film, improving adhesion to the target object. Furthermore, when the viscoelasticity of the cured film formed by curing this photocurable composition is measured at a frequency of 1 Hz, the elastic modulus at 80°C is 2.0 × 10⁶ Pa or higher and 1.0 × 10⁹ Pa or lower. Therefore, the cured film formed by the reaction of components (AC), (A), and (I) possesses sufficient strength, and the pattern structure is not easily deformed, while maintaining strong adhesion to the bonded object. Furthermore, during pattern formation, a well-shaped, high-resolution pattern can be formed, improving the photolithography properties. Therefore, the photocurable composition of this embodiment has good pattern-forming properties and high reliability, which can improve the adhesion to the object when the curing film is made.

[0199] Furthermore, the photocurable composition of this embodiment can also improve the structural retention of the pattern under external force when bonded to an object. Furthermore, electronic components using the photocurable composition of this embodiment exhibit improved durability in the operating environment, enabling stable and continuous use and enhancing reliability. The photocurable composition of this embodiment combines patterning properties, reliability, and adhesion, and can be used as a photocurable adhesive material for manufacturing electronic components requiring various properties (such as MEMS, biological applications, etc.).

[0200] (Pattern Formation Method) The pattern forming method of this embodiment includes the following steps: forming a photocurable film on a support using the photocurable composition of the above embodiment (hereinafter referred to as the "film forming step"); exposing the photocurable film to light (hereinafter referred to as the "exposure step"); and developing the exposed photocurable film using a developer containing an organic solvent to form a negative pattern (hereinafter referred to as the "development step"). The pattern forming method of this embodiment can be performed, for example, in the following manner.

[0201] [Film Formation Steps] First, the photocurable composition of the above embodiment is coated onto a support using known methods such as spin coating, roller coating, or screen printing. Then, a photocurable film is formed by baking (post apply bake, PAB) at a temperature of, for example, 50 to 150°C for 2 to 60 minutes.

[0202] There are no particular limitations on the support substrate; previously known substrates can be used, such as substrates for electronic components or substrates with specific wiring patterns formed thereon. More specifically, examples include metal substrates made of silicon, silicon nitride, titanium, tantalum, lithium tantalate (LiTaO3), niobium, lithium niobate (LiNbO3), palladium, titanium tungsten, copper, chromium, iron, aluminum, or glass substrates. Materials used for wiring patterns include, for example, copper, aluminum, nickel, and gold.

[0203] The thickness of the photocurable film formed from the photocurable composition is not particularly limited, but is preferably around 10 to 50 μm.

[0204] [Exposure Steps] Secondly, selective exposure is achieved by using a known exposure device to expose the photocurable film formed through a mask (mask pattern) with a specific pattern, or by directly irradiating an electron beam to draw the image without a mask pattern. After the above selective exposure, a baking (post-exposure bake, PEB) process is performed as needed, for example at a temperature of 80~150°C for 40~1200 seconds, preferably 40~1000 seconds, and even more preferably 60~900 seconds.

[0205] There is no particular limitation on the wavelength used during exposure. The radiation is selectively irradiated, such as ultraviolet light with a wavelength of 300-500 nm, gamma rays, h rays, i rays (wavelength 365 nm), or visible light. As a source of such radiation, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, argon lasers, etc., can be used. Here, radiation refers to ultraviolet light, visible light, far ultraviolet light, X-rays, electron beams, etc. The radiation dose varies depending on the type and amount of each component in the composition, the thickness of the coating, etc. For example, it is 100~2000 mJ / cm2 when using an ultra-high pressure mercury lamp.

[0206] The exposure method for photocurable films can be conventional exposure (dry exposure) in air or inert gases such as nitrogen, or liquid immersion lithography.

[0207] The photocurable film after the exposure step has high transparency. For example, when irradiated with i-rays (wavelength 365 nm), the haze value is preferably below 3%, and more preferably 1.0~2.7%. The haze value of the photocurable film after the exposure step was determined according to the method of JIS K 7136 (2000).

[0208] [Developing Steps] Next, the photocurable film exposed to the above exposure is developed using a developer containing organic solvents (organic developer). After development, it is preferable to perform a cleaning process. Baking (post-baking) may also be performed if necessary.

[0209] As for the organic solvent contained in an organic developer, it is only necessary to be able to dissolve the (A) and (AC) components before exposure, and it can be appropriately selected from known organic solvents. Specifically, examples include: ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents and other polar solvents, hydrocarbon solvents, etc.

[0210] Examples of ketone solvents include: 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetoacetone, acetone-based acetone, ionone, diacetone alcohol, acetoethanol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methylpentyl ketone (2-heptanone), etc. Among these, methylpentyl ketone (2-heptanone) is preferred as a ketone solvent.

[0211] Examples of ester-based solvents include: methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxy, ethyl ethoxy, propylene glycol monomethyl ether acetate (PGMEA), ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, etc. 4-Ethoxybutyl acetate, 4-Propoxybutyl acetate, 2-Methoxypentyl acetate, 3-Methoxypentyl acetate, 4-Methoxypentyl acetate, 2-Methyl-3-Methoxypentyl acetate, 3-Methyl-3-Methoxypentyl acetate, 3-Methyl-4-Methoxypentyl acetate, 4-Methyl-4-Methoxypentyl acetate, Propylene glycol diacetate, Methyl formate, Ethyl formate, Butyl formate, Propyl formate, Ethyl lactate Butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, etc. Among these, butyl acetate or PGMEA is preferred as an ester solvent.

[0212] Examples of nitrile solvents include acetonitrile, propionitrile, valerate, and butyronitrile.

[0213] As needed, known additives can be formulated into organic developing solutions. Examples of such additives include surfactants. There are no particular limitations on the surfactant; for example, ionic or nonionic fluorinated and / or silicone surfactants can be used. As a surfactant, it is preferably a nonionic surfactant, more preferably a nonionic fluorinated surfactant or a nonionic silicone surfactant. When preparing surfactants, the amount prepared relative to the total amount of organic developer is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and even more preferably 0.01 to 0.5% by mass.

[0214] The development process can be carried out using known development methods, such as the following: immersing the support in the developer for a certain period of time (immersion method); allowing the developer to accumulate on the surface of the support under the action of surface tension and then remain still for a certain period of time (coating method); spraying the developer onto the surface of the support (spraying method); and continuously spraying the developer onto a uniformly rotating support while scanning at a constant speed with one end of the nozzle (dynamic dispense method), etc.

[0215] Cleaning treatment (washing treatment) using a cleaning solution can be carried out by known cleaning methods. Examples of such cleaning treatment methods include: continuously spraying cleaning solution onto a uniformly rotating support (spin coating method); immersing the support in the cleaning solution for a certain period of time (immersion method); spraying cleaning solution onto the surface of the support (spraying method), etc. The best cleaning treatment is to use a cleaning solution containing organic solvents.

[0216] After the above film-forming, exposure, and development steps, a pattern can be formed.

[0217] In the pattern forming method of the above embodiments, the photocurable composition of the above embodiments is used. Therefore, when forming a pattern, a resin pattern with high resolution and good shape is formed, and the photolithography properties are excellent.

[0218] (hardened film) The hardened film of this embodiment is formed by hardening the photocurable composition of the above embodiment. Regarding the hardened film of this embodiment, when the viscoelasticity is measured at a frequency of 1 Hz, the elastic modulus at a temperature of 80°C is 2.0 × 10⁶ Pa or more and 1.0 × 10⁹ Pa or less, preferably 2.0 × 10⁶ Pa or more and 8.0 × 10⁸ Pa or less, and even more preferably 2.5 × 10⁶ Pa or more and 7.5 × 10⁸ Pa or less. The adhesion between the hardened film and the object is enhanced in this embodiment. Furthermore, in the TCT test, the hardened film of this embodiment maintains a strong bond with the object, improving reliability. Also, the hardened film of this embodiment is less prone to pattern deformation, exhibiting structural integrity.

[0219] (Manufacturing method of hardened film) The method for manufacturing the curing film according to this embodiment includes the following steps: step (i), which involves forming a photocurable film on a support using the photocurable composition of the above embodiment; and step (ii), which involves curing the photocurable film to obtain a curing film. Step (i) can be performed in the same manner as the [film formation step] described above. The baking process can be performed, for example, at a temperature of 80-150°C for 40-600 seconds. The hardening treatment in step (ii) can be carried out, for example, at a temperature of 100-250°C for 0.5-2 hours.

[0220] The method for manufacturing the curing film in this embodiment may also include steps other than step (i) and step (ii). For example, the above-mentioned [exposure step] may be included between step (i) and step (ii) to selectively expose the photocurable film formed in step (i) so that the photocurable film (pre-cured film) that needs to be baked (PEB) can be cured, and a curing film can also be obtained. According to the method for manufacturing a curing film according to the above embodiments, since the photocurable composition of the above embodiments is used, a curing film with improved adhesion to electronic components such as silicon wafers that are the objects can be manufactured. Furthermore, according to this method for manufacturing a curing film, a curing film with a pattern structure that is not easily deformed and which maintains a high reliability in terms of adhesion strength to the bonded object can be manufactured. [Example]

[0221] The present invention will now be described in more detail by way of examples, but the present invention is not limited to the examples below.

[0222] <Manufacturing of Acrylic Resins> Using the monomers from which the structural units are sourced as shown in Table 1, conventional free radical polymerization was carried out to obtain acrylic resins (AC)-1 to (AC)-9 and acrylic resins (AC)-11 to (AC)-14, respectively.

[0223] Table 1 shows the ratio of each structural unit constituting the acrylic resin, the glass transition temperature Tg (°C) of the acrylic resin as a characteristic of the acrylic resin, the content ratio (mass %) of the structural unit (ac1) in the acrylic resin, and the weight average molecular weight Mw of the acrylic resin.

[0224] The glass transition temperature of acrylic resins is calculated using the following formula. 1 / (Tg+273) ={W1 / (Tg1+273)+W2 / (Tg2+273)+···} / 100 Tg: Glass transition temperature (°C) of copolymers of acrylic resins. Tg1: Glass transition temperature (°C) of homopolymers containing repeating structural units (1) derived from monomer (1). Tg2: Glass transition temperature (°C) of homopolymers containing repeating structural units (2) derived from monomer (2). W1: The ratio (mass %) of the structural unit (1) constituting the acrylic resin. W2: The ratio (mass%) of the structural unit (2) constituting the acrylic resin. W1 + W2 + ... = 100

[0225] The glass transition temperatures of the homopolymers are based on values ​​disclosed in the homepage of KTR Corporation (www.kaji-tr.com), the "Polymer Materials Handbook" (edited by the Polymer Society, Corona Corporation, first edition, published February 20, 1973), the acrylic product catalog of Kyoei Chemical Co., Ltd., and the "Polymer Data Handbook: Fundamentals" (edited by the Polymer Society, Peifengkan, published January 30, 1986).

[0226] For example, the glass transition temperature Tg (°C) of acrylic resin (AC)-2 can be calculated using the following method. Acrylic resin (AC)-2 is a copolymer of structural units derived from 2-methoxyethyl acrylate and structural units derived from n-butyl acrylate. If monomer (1) is set as 2-methoxyethyl acrylate, then the glass transition temperature of the homopolymer containing the repeating structure of structural unit (1) is -50°C, and the ratio of structural unit (1) is 73 by mass. If monomer (2) is set as n-butyl acrylate, the glass transition temperature of the homopolymer containing the repeating structure of structural unit (2) is -56°C, and the ratio of structural unit (2) is 27 by mass. The glass transition temperature Tg (°C) of acrylic resin (AC)-2 is calculated using the following formula. 1 / (Tg+273) ={73 / (-50+273)+27 / (-56+273)} / 100 Tg≒-52℃

[0227] For each acrylic resin obtained, the copolymer composition ratio (the ratio (mass %) of each structural unit constituting the acrylic resin) was determined by 13C-NMR. The weight-average molecular weight (Mw) of the acrylic resin was determined by gel permeation chromatography (GPC) and expressed as a standard polystyrene equivalent.

[0228] [Table 1] Ratio / mass% of each structural unit constituting acrylic resin Characteristics of acrylic resins Structural unit (ac2) Structural unit (ac1) Structural unit Source monomer acrylic acid 2-Methoxyethyl ester methacrylic acid 2-Hydroxyethyl ester acrylic acid n-Butyl ester methacrylic acid n-Butyl ester acrylic acid 2-Ethylhexyl ester methacrylic acid lauryl ester styrene methacrylic acid Methyl ester methacrylic acid Isobutyl ester methacrylic acid glycidyl esters Glass transition temperature of acrylic resins Tg (°C) The percentage / mass of structural unit (ac1) in acrylic resins Weight average molecular weight (Mw) of acrylic resins homopolymers Glass transition temperature Tg (°C) -50 +55 -56 +20 -70 -65 +100 +105 +53 +46 molecular weight of monomers 130 130 128 142 184 254 104 100 222 142 acrylic resin (AC)-1 20 0 0 80 0 0 0 0 0 0 +3 0 300000 (AC)-2 73 0 27 0 0 0 0 0 0 0 -52 0 290000 (AC)-3 72.5 0 27 0 0 0 0 0 0 0.5 -51 0.5 300000 (AC)-4 72.5 0 0 27 0 0 0 0 0 0.5 -34 0.5 350000 (AC)-5 38.5 0 0 61 0 0 0 0 0 0.5 -12 0.5 250000 (AC)-6 98 1.5 0 0 0 0 0 0 0 0.5 -49 0.5 150000 (AM)-7 97.5 2 0 0 0 0 0 0 0 0.5 -48 0.5 180000 (AC)-8 98.5 1.5 0 0 0 0 0 0 0 0 -49 0 120000 (AC)-9 0 25 0 0 41 34 0 0 0 0 -47 0 22000 (AC)-11 27 0 0 0 0 0 73 0 0 0 +43 0 300000 (AM)-12 23 0 0 75 0 0 0 0 0 2 +1 2 300000 (AC)-13 0 28 0 0 0 0 0 42 30 0 +74 0 120000 (AC)-14 0 0 0 0 0 0 0 59 41 0 +82 0 51000

[0229] <Preparation of Photocurable Compositions> (Examples 1-13, Comparative Examples 1-7) The components shown in Tables 2 and 3 were mixed in methyl ethyl ketone and dissolved. The mixture was then filtered using a PTFE filter (1 μm pore size, manufactured by PALL) to prepare light-curing compositions for each example (solutions with a solid content of 73% by mass and a viscosity of 1500 mPa·s at 23°C).

[0230] [Table 2] acrylic resins Epoxy compounds cationic polymerization initiator Elastic modulus at 80℃ / Pa (AC) components (A1)Ingredients (A2) Ingredients (I)Ingredients Example 1 (AC)-3

[20] - (A2)-1

[80] (I)-1 [0.5] 2.1×10⁷ Example 2 (AC)-8

[25] (A1)-2

[75] - (I)-1 [0.5] 5.7×10⁸ Example 3 (AC)-3

[20] (A1)-1

[80] - (I)-1 [0.5] 7.0×10⁸ Example 4 (AC)-9

[20] (A1)-1

[80] - (I)-1 [0.5] 7.1×10⁸ Example 5 (AC)-3

[10] - (A2)-1

[90] (I)-1 [0.5] 9.0×10⁷ Example 6 (AC)-5

[20] (A1)-1

[80] - (I)-1 [0.5] 7.8×10⁸ Example 7 (AC)-7

[30] (A1)-1

[70] - (I)-1 [0.5] 6.2×10⁷ Example 8 (AC)-3

[40] - (A2)-2

[60] (I)-1 [0.5] 3.2×10⁶ Example 9 (AC)-3

[10] (A1)-1

[90] - (I)-1 [0.5] 7.9×10⁸ Example 10 (AC)-2

[60] - (A2)-1

[40] (I)-1 [0.5] 2.9×10⁶ Example 11 (AC)-4

[20] (A1)-1

[80] - (I)-1 [0.5] 6.4×10⁸ Example 12 (AC)-6

[15] - (A2)-1

[85] (I)-1 [0.5] 5.0×10⁷ Example 13 (AC)-3

[20] (A1)-1

[40] (A2)-1

[40] (I)-1 [0.5] 5.6×10⁷

[0231] [Table 3] acrylic resins Epoxy compounds cationic polymerization initiator Elastic modulus at 80℃ / Pa (AC) components (A1)Ingredients (A2) Ingredients (I)Ingredients Comparative Example 1 (AC)-11

[20] - (A2)-1

[80] (I)-1 [0.5] 1.1×10⁹ Comparative Example 2 (AC)-13

[20] - (A2)-1

[80] (I)-1 [0.5] 2.1×10⁹ Comparative Example 3 (AC)-1

[20] (A1)-1

[80] - (I)-1 [0.5] 1.7×10⁹ Comparative Example 4 (AC)-14

[20] (A1)-1

[80] - (I)-1 [0.5] 1.9×10⁹ Comparative Example 5 - - (A2)-1

[0100] (I)-1 [0.5] 1.4×10⁹ Comparative Example 6 (AC)-12

[20] - (A2)-1

[80] (I)-1 [0.5] 1.2×10⁹ Comparative Example 7 (AC)-2

[70] - (A2)-1

[30] (I)-1 [0.5] 1.7×10⁶

[0232] In Tables 2 and 3, each abbreviation symbol has the following meaning. The value in [] represents the amount of each component (parts by mass; conversion of solid content).

[0233] (AC)-1~(AC)-9: Acrylic resins (AC)-1~(AC)-9 as shown in Table 1 (AC)-11~(AC)-14: Acrylic resins (AC)-11~(AC)-14 shown in Table 1

[0234] (A1)-1: Solid phenolic varnish-type epoxy resin represented by the following chemical formula (anv0-1). Trade name "jER-157S70", manufactured by Mitsubishi Chemical Co., Ltd. Softening point 70℃, glass transition temperature 210℃, epoxy equivalent 200~220 g / eq.

[0235] [Chemistry 36]

[0236] (A1)-2: A solid cresol phenolic varnish-type epoxy resin obtained by glycidyl etherification of o-cresol varnish. Trade name: "YDCN-704", manufactured by Nippon Steel & Sumitomo Metal Corporation. Softening point: 87~97℃, glass transition temperature: 255℃, epoxy equivalent: 202~214 g / eq.

[0237] (A2)-1: Solid bisphenol type epoxy resin represented by the following chemical formula (abp1-0). Trade name "jER-1002", manufactured by Mitsubishi Chemical Co., Ltd. Softening point 78℃, weight average molecular weight 1200, epoxy equivalent 600~700 g / eq. (A2)-2: Solid bisphenol type epoxy resin represented by the following chemical formula (abp1-0). Trade name "jER-1003", manufactured by Mitsubishi Chemical Co., Ltd. Softening point 89℃, weight average molecular weight 1300, epoxy equivalent 670~770 g / eq.

[0238] [Chemistry 37]

[0239] (I)-1: The cationic polymerization initiator represented by the following chemical formula (I2-1-2).

[0240] [Chemistry 38]

[0241] <Evaluation> For each example of a photocurable composition, the modulus of elasticity at 80°C was determined by the method shown below. Furthermore, for each example of a photocurable composition, adhesion, reliability, lithography properties, and structure retention were evaluated using the evaluation methods shown below. The results are presented in Tables 4 and 5.

[0242] [Determination of elastic modulus at 80℃] Using a coating apparatus, each of the photocurable compositions was coated onto a PET film (after release treatment) of a substrate, and then baked in an oven at 60°C for 5 minutes, 70°C for 5 minutes, and 80°C for 10 minutes in sequence to dry it and form a photocurable film with a thickness of 50 μm. Next, the entire surface of the photocurable film is exposed to gamma rays, h rays, and i rays with an irradiation dose capable of forming a pattern of 100 μm for each component. Subsequently, it is exposed to a heating plate at 90°C for 5 minutes and then heated to obtain the target cured film.

[0243] The elastic modulus of the obtained hardened film was determined by the following method. The hardened film was peeled off from the PET film and cut into pieces of 5 mm × 20 mm size to serve as a sample for measuring the elastic modulus. The viscoelasticity of the sample was measured using the following evaluation apparatus and measurement conditions, thereby determining the elastic modulus of the hardened film. • Measuring apparatus: Dynamic viscoelasticity apparatus (manufactured by UBM) • Measurement conditions: tensile mode, frequency 1.0 Hz, clamp spacing 10 mm, temperature 80℃, heating rate 5℃ / min The higher the elastic modulus, the higher the strength of the hardened film.

[0244] [Evaluation of the next stage] Fabrication of the substrate for measurement: After each photocurable composition was coated onto a silicon substrate by spin coating, it was baked in an oven at 60°C for 5 minutes, 70°C for 5 minutes, and 80°C for 10 minutes in sequence to form a cured film with a thickness of 20 μm. Next, the hardened film formed on the silicon substrate is bonded to a 5 mm square silicon wafer. Then, using a die bonder (manufactured by TRESKY Corporation), a load of 3500 g is applied for 60 seconds at a temperature of 150°C to heat-press the hardened film to the 5 mm square silicon wafer, thereby producing a substrate for testing.

[0245] • Determination of shear strength At room temperature (23°C), using an adhesive strength tester (XYZTEC, Condor Sigma), the above-mentioned test substrate was fixed, and shear force was applied to a 5 mm square silicon wafer portion to measure the force (shear strength, N / mm²) required to peel the 5 mm square silicon wafer from the hardened film.

[0246] • Evaluation of the joint status Using the shear strength between the hardened film and a 5 mm square silicon wafer as an indicator, the bonding state was observed according to the following evaluation criteria to evaluate the adhesion. Evaluation Criteria 〇: The shear strength is above 5 N / mm², and the two are firmly bonded together. ×: The shear strength is less than 5 N / mm², the adhesion is weak, and a 5 mm square silicon wafer is easily peeled off from the hardened film.

[0247] [Reliability Evaluation] Reliability is evaluated using the thermal cycling test (TCT) shown below. Fabrication of substrates for TCT measurements In the fabrication of the substrate for the measurement described in the above [adhesion evaluation], the 5 mm square silicon wafer was replaced with a 5 mm square glass. Otherwise, the hardened film was hot-pressed onto the 5 mm square glass in the same manner to fabricate a substrate for TCT measurement. ·TCT Thermal cycling tests were conducted under the following test conditions. Set temperature and time cycle: -55℃~125℃ (each cycle is 30 minutes) Test duration: 1000 hours Evaluation criteria The condition of the substrate used for testing after the thermal cycling test is observed. If the hardened film does not peel off from the 5 mm square glass, it is judged as "0"; if the hardened film peels off from the 5 mm square glass, it is judged as "×". The reliability is evaluated. Furthermore, the term "ND" in the table indicates that a pattern cannot be formed before hardening, making TCT impossible.

[0248] [Evaluation of Microfilm Characteristics] Patterns were formed using the photocurable compositions of each example. Film formation steps: Each photocurable composition was coated onto a silicon substrate using a spin coating method. Then, the substrate was sequentially baked in an oven at 60°C for 5 minutes, 70°C for 5 minutes, and 80°C for 10 minutes to form photocurable films with a thickness of 20 μm.

[0249] Exposure steps: Secondly, the photocurable film was irradiated with gamma rays, h rays, and i rays using an exposure machine (Prisma ghi). Next, the photocurable film after exposure is exposed to a heating plate at 90°C for 5 minutes and then heated.

[0250] Development steps: Next, propylene glycol monomethyl ether acetate (PGMEA) was used as the developer, and the photocurable film after exposure and heating was subjected to a 15-minute incubation development at room temperature (23°C).

[0251] Using the aforementioned film formation, exposure, and development steps, an attempt was made to form a line and gap pattern with a linewidth of 100 μm and a gap width of 300 μm (hereinafter referred to as the "L / S pattern"). Then, the state of the L / S pattern was observed according to the following evaluation criteria to evaluate its lithography properties. Evaluation Criteria 〇: Form a well-shaped line with a width of 100 μm. The shape of the ×:L / S pattern is not good.

[0252] [Evaluation of structural integrity] Line patterns are formed on a silicon substrate using the same method as the pattern formation method described in the above [Evaluation of Photolithography Characteristics]. Secondly, the material was hardened by heating at 200°C for 1 hour in a nitrogen atmosphere to obtain a hardened film with a linewidth of 700 μm. Next, a 700 μm linewidth hardened film formed on a silicon substrate is bonded to a 5 mm square glass. Subsequently, a die bonder (manufactured by TRESKY Corporation) is used to perform thermo-press bonding by applying a bonding load of 3000 g for 60 minutes at a temperature of 100°C. Furthermore, based on the following evaluation criteria, the state of the hardened film after 60 minutes of hot pressing was observed to evaluate its structural integrity. Evaluation Criteria 〇: The variation in line width did not reach 20 μm. ×: The variation in line width is 20 μm or more. The smaller the variation in line width, the less the pattern structure is deformed and the higher the structural integrity.

[0253] [Table 4] Adhesion reliability TCT Lithography characteristics 100 / 300 μm L / S Construction preservation Shear strength N / mm 2 Engagement state Example 1 39.0 〇 〇 〇 〇 Example 2 16.8 〇 〇 〇 〇 Example 3 14.0 〇 〇 〇 〇 Example 4 10.4 〇 〇 〇 〇 Example 5 17.2 〇 〇 〇 〇 Example 6 6.1 〇 〇 〇 〇 Example 7 21.0 〇 〇 〇 〇 Example 8 39.8 〇 〇 〇 〇 Example 9 6.5 〇 〇 〇 〇 Example 10 41.8 〇 〇 〇 〇 Example 11 13.1 〇 〇 〇 〇 Example 12 38.5 〇 〇 〇 〇 Example 13 25.0 〇 〇 〇 〇

[0254] [Table 5] Adhesion reliability TCT Lithography characteristics 100 / 300 μm L / S Construction preservation Shear strength N / mm 2 Engagement state Comparative Example 1 2.5 × × 〇 〇 Comparative Example 2 1.6 × × 〇 〇 Comparative Example 3 1.0 × × 〇 〇 Comparative Example 4 0.9 × × 〇 〇 Comparative Example 5 1.5 × × 〇 〇 Comparative Example 6 3.5 × × 〇 〇 Comparative Example 7 43.1 〇 ND × ×

[0255] Based on the results in Tables 4 and 5, it can be confirmed that the photocurable compositions of Examples 1 to 13 of the present invention can improve the adhesion to the object when the curing film is made, have high reliability and durability in response to temperature changes, and form well-shaped patterns when patterning, with excellent photolithography properties. Furthermore, it can be confirmed that the photocurable compositions of Examples 1-13 have high structural retention. On the other hand, the photocurable compositions of Comparative Examples 1 to 7, which are outside the scope of this invention, showed poorer evaluation results in any one or more aspects of adhesion, reliability, and lithography properties.

[0256] The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications can be made to the structure without departing from the spirit of the present invention. The present invention is limited only by the appended claims and not by the foregoing description.

Claims

1. A photocurable composition comprising an acrylic resin (AC) and an epoxy-containing compound (A) (wherein, Except for those conforming to the above-mentioned acrylic resin (AC) and cationic polymerization initiator (I), the glass transition temperature of the above-mentioned acrylic resin (AC) is -75°C to -5°C, the above-mentioned epoxy compound (A) includes at least one epoxy resin selected from the group consisting of bisphenol type epoxy resin and phenolic varnish type epoxy resin, and when the viscoelasticity of the cured film formed by curing the above-mentioned photocurable composition is measured at a frequency of 1 Hz, the elastic modulus at a temperature of 80°C is 2.0×10⁶ [Pa] to 1.0×10⁹ [Pa].

2. The photocurable composition of claim 1, wherein the mixing ratio of the acrylic resin (AC) and the epoxy compound (A) is, by mass ratio, 40 / 60 to 95 / 5.

3. The photocurable composition of claim 1 or 2, wherein the acrylic resin (AC) has a structural unit (ac1) derived from an acrylic monomer containing an epoxy group.

4. The photocurable composition of claim 1 or 2, wherein the content of the cationic polymerization initiator (I) is 0.05 to 5 parts by mass relative to the total content of the acrylic resin (AC) and the epoxy compound (A) of 100 parts by mass.

5. A pattern forming method comprising the steps of: forming a photocurable film on a support using a photocurable composition as claimed in claim 1 or 2; exposing the photocurable film to light; and developing the exposed photocurable film using a developer containing an organic solvent to form a negative pattern.

6. A curing film using a photocurable composition as claimed in claim 1 or 2.