Negative photosensitive composition, photosensitive resist film, method for producing hollow structure, and pattern forming method

Abstract

Provided are a negative photosensitive composition capable of forming a pattern having a good shape and capable of enhancing adhesion to a side wall of a hollow structure, a photosensitive resist film having a photosensitive film formed by using the negative photosensitive composition, and a method for manufacturing a hollow structure and pattern forming method that use the negative photosensitive composition. The negative photosensitive composition contains a trifunctional or higher polyfunctional epoxy compound, a cationic polymerization initiator, and a bifunctional aromatic epoxy compound having a molecular weight of 800 or less. In this negative photosensitive composition, the proportion of the content of the bifunctional aromatic epoxy compound is 0.6–10% by mass with respect to the total content (100% by mass) of the polyfunctional epoxy compound and the bifunctional aromatic epoxy compound.

Description

Negative photosensitive composition, photosensitive resist film, method for producing hollow structure, and method for forming pattern

[0001] The present invention relates to a negative-working photosensitive composition, a photosensitive resist film, a method for manufacturing a hollow structure, and a pattern formation method. This application claims priority based on Japanese Patent Application No. 2023-185656, filed on October 30, 2023, the contents of which are incorporated herein by reference.

[0002] In recent years, the development of microelectronic devices such as surface acoustic wave (SAW) filters has progressed. Packages that encapsulate such electronic devices have a hollow encapsulation structure to ensure the propagation of surface acoustic waves and the mobility of movable parts of the electronic devices. In the future, there will be an increasing demand for miniaturization of packages with hollow encapsulation structures (hereinafter referred to as hollow structures), particularly for smartphones and other devices that handle high frequencies.

[0003] 3 is a schematic cross-sectional view showing an example of the structure of a hollow structure 100. The hollow structure 100 includes a substrate 10, a sidewall 20 formed on the substrate 10, and a negative pattern (exposed portion 30A, hereinafter also referred to as a top plate portion) that covers the opening of a recess 15 formed by the sidewall 20 and the substrate 10. The hollow structure 100 is manufactured, for example, as follows. First, the sidewall 20 is manufactured by selectively exposing a photosensitive film formed by applying a photosensitive composition to the substrate 10. Next, a photosensitive film is attached to the sidewall 20 so as to cover the recess 15, and then selectively exposing the film to form the top plate portion 30A.

[0004] When forming the sidewall of a hollow structure on a substrate, there is a problem that undercuts are likely to occur at the peripheral edge of the negative pattern that contacts the substrate. In response to this problem, Patent Document 1 discloses a negative photosensitive resin composition containing an epoxy group-containing compound and a resin having specific structural units.

[0005] Japanese Patent Application Laid-Open No. 2022-101132

[0006] However, the top plate portion produced using the negative photosensitive resin composition of Patent Document 1 has a problem in that it does not have sufficient adhesion to the side wall formed on the substrate.

[0007] Therefore, an object of the present invention is to provide a negative photosensitive composition that can form a pattern of good shape and has improved adhesion to the side walls of hollow structures, a photosensitive resist film having a photosensitive film formed using the composition, a method for manufacturing a hollow structure using the negative photosensitive composition, and a pattern formation method.

[0008] The present invention includes the following aspects: A first aspect of the present invention is a negative-type photosensitive composition comprising a tri- or higher functional polyfunctional epoxy compound, a cationic polymerization initiator, and a bifunctional aromatic epoxy compound having a molecular weight of 800 or less, wherein the content of the bifunctional aromatic epoxy compound is 0.6 to 10 mass % relative to the total content (100 mass %) of the polyfunctional epoxy compound and the bifunctional aromatic epoxy compound.

[0009] A second aspect of the present invention is a photosensitive resist film in which a photosensitive film formed using the negative photosensitive composition according to the first aspect and a cover film are laminated in this order on a base film.

[0010] A third aspect of the present invention is a method for manufacturing a hollow structure comprising a recess and a top plate portion covering the opening surface of the recess, wherein the top plate portion is formed using the negative-type photosensitive composition according to the first aspect.

[0011] A fourth aspect of the present invention is a pattern forming method, comprising the steps of: forming a photosensitive film on a support using the negative photosensitive composition according to the first aspect; exposing the photosensitive film; and developing the exposed photosensitive film with a developer containing an organic solvent to form a negative pattern.

[0012] According to the present invention, it is possible to provide a negative photosensitive composition that can form a pattern of good shape and has improved adhesion to the sidewall of a hollow structure, a photosensitive resist film having a photosensitive film formed using the same, a method for manufacturing a hollow structure using the negative photosensitive composition, and a pattern formation method.

[0013] 1 is a schematic diagram illustrating a method for manufacturing a hollow structure according to an embodiment of the present invention; FIG. 2 is a diagram illustrating a taper angle formed by a residual film of a photosensitive film and a silicon wafer in an example; and FIG. 3 is a diagram illustrating a cross section of a hollow structure according to an embodiment of the present invention.

[0014] In this specification and claims, "aliphatic" is a relative concept to aromatic, and is defined as meaning a group or compound that does not have aromaticity. Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups. A "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with halogen atoms, and examples of such halogen atoms include fluorine, chlorine, bromine, and iodine atoms. A "fluorinated alkyl group" is a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with fluorine atoms. When describing "optionally having a substituent," it is intended to mean the case where a hydrogen atom (-H) is substituted with a monovalent group, and the case where a methylene group (-CH ２ The term "exposure" encompasses both cases where the radical (-) is substituted with a divalent group and cases where the radical (-) is substituted with a divalent group. The term "exposure" encompasses all cases of irradiation with radiation.

[0015] (Negative Photosensitive Composition) The negative photosensitive composition according to this embodiment contains a tri- or higher functional polyfunctional epoxy compound (Ap), a cationic polymerization initiator (I), and a bifunctional aromatic epoxy compound (Am) having a molecular weight of 800 or less. Hereinafter, the tri- or higher functional polyfunctional epoxy compound will be referred to as the "(Ap) component," and the bifunctional aromatic epoxy compound will be referred to as the "(Am) component." The tri- or higher functional polyfunctional epoxy compound (Ap) and the bifunctional aromatic epoxy compound (Am) will be referred to simply as "epoxy compounds" ("(A) component"). The cationic polymerization initiator (I) will also be referred to as the "(I) component."

[0016] The content of the component (Am) is 0.6 to 10% by mass relative to the total content (100% by mass) of the components (Ap) and (Am).

[0017] When a photosensitive film is formed using such a negative photosensitive composition and the photosensitive film is selectively exposed to light, the cationic moiety of the cationic polymerization initiator decomposes in the exposed areas of the photosensitive film to generate an acid, and the action of the acid causes ring-opening polymerization of the epoxy groups in component (A), reducing the solubility of component (A) in a developer containing an organic solvent (organic developer). Meanwhile, the solubility of component (A) in an organic developer remains unchanged in the unexposed areas of the photosensitive film, resulting in a difference in solubility in an organic developer between the exposed and unexposed areas of the photosensitive film. Therefore, when the photosensitive film is developed with an organic developer, the unexposed areas are dissolved and removed, forming a negative pattern.

[0018] <Tri- or Higher Functional Polyfunctional Epoxy Compound (Ap)> As the component (Ap), a tri- or higher functional polyfunctional epoxy compound having sufficient epoxy groups to form a negative pattern by exposure is used.

[0019] As the trifunctional or higher polyfunctional epoxy compound, bisphenol novolac epoxy resin is preferred. Examples of bisphenol novolac epoxy resins include polyfunctional epoxy resins produced by reacting bisphenol novolac resin with epichlorohydrin, and polyfunctional epoxy resins obtained by novolacizing bisphenol glycidyl ether. Among these, bisphenol A novolac epoxy resins are preferred because of their easy availability.

[0020] Suitable examples of bisphenol novolac epoxy resins include resins represented by the following general formula (Ap-1):

[0021] [In formula (Ap-1), R ｐ１ and R ｐ２ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ｐ１ may be the same or different. ｐ２ may be the same or different. １ is an integer from 1 to 5. ＥＰis an epoxy group-containing group. ＥＰ may be the same or different from each other.

[0022] In the formula (Ap-1), R ｐ１ , R ｐ２ The alkyl group having 1 to 5 carbon atoms is, for example, a linear, branched, or cyclic alkyl group having 1 to 5 carbon atoms. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group, and examples of the cyclic alkyl group include a cyclobutyl group and a cyclopentyl group. Among these, R ｐ１ , R ｐ２ is preferably a hydrogen atom or a linear or branched alkyl group, more preferably a hydrogen atom or a linear alkyl group, and particularly preferably a hydrogen atom or a methyl group. ｐ１ may be the same or different. ｐ２ may be the same as or different from each other.

[0023] In formula (Ap-1), n １ is an integer of 1 to 5, preferably 2 or 3, and more preferably 2.

[0024] In formula (Ap-1), R ＥＰ is an epoxy group-containing group. ＥＰThe epoxy group-containing group is not particularly limited, and examples thereof include a group consisting of only epoxy groups; a group consisting of only alicyclic epoxy groups; and a group having an epoxy group or alicyclic epoxy group and a divalent linking group. An alicyclic epoxy group is an alicyclic group having an oxacyclopropane structure, which is a three-membered ring ether, specifically a group having an alicyclic group and an oxacyclopropane structure. The alicyclic group that forms the basic skeleton of the alicyclic epoxy group may be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of polycyclic alicyclic groups include norbornyl, isobornyl, tricyclononyl, tricyclodecyl, and tetracyclododecyl groups. The hydrogen atoms of these alicyclic groups may be substituted with alkyl groups, alkoxy groups, hydroxyl groups, or the like. In the case of a group having an epoxy group or an alicyclic epoxy group and a divalent linking group, it is preferable that the epoxy group or the alicyclic epoxy group is bonded via the divalent linking group bonded to an oxygen atom (—O—) in the formula.

[0025] Here, the divalent linking group is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0026] Regarding the divalent hydrocarbon group which may have a substituent: The divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group in the divalent hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0027] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specifically, a methylene group [—CH ２-], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, even more preferably 2 to 4 carbon atoms, and most preferably 2 or 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２-, -CH ２ CH (CH ３ ) CH ２ CH ２ Examples of alkyl groups include alkyl tetramethylene groups such as -, etc. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0028] Examples of the aliphatic hydrocarbon group containing a ring in its structure include alicyclic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0029] 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 having (4n+2) π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2, and particularly preferably 1 carbon atom.

[0030] The divalent hydrocarbon group may have a substituent. The linear or branched aliphatic hydrocarbon group as the divalent hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0031] The alicyclic hydrocarbon group in the aliphatic hydrocarbon group containing a ring in its structure as a divalent hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. In the alicyclic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, and -S(=O) ２ -, -S(=O) ２ —O— is preferred.

[0032] In the aromatic hydrocarbon group as a divalent hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the alicyclic hydrocarbon group.

[0033] Regarding the divalent linking group containing a hetero atom: The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom or a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

[0034] In the divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-; -C(=O)-NH-, -NH-, -NH-C(=O)-O-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group); -S-, -S(=O) ２ -, -S(=O) ２ -O-, general formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ , -[Y ２１ -C(=O)-O] ｍ” -Y ２２ - or -Y ２１ -OC(=O)-Y ２２ -, wherein Y ２１ and Y ２２ are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -NH-, -NH-C(=O)-O-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. Formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C(=O)-O] ｍ” -Y ２２ - or -Y ２１ -OC(=O)-Y ２２ -Middle, Y２１ and Y ２２ are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same as the "divalent hydrocarbon group which may have a substituent" listed above in the description of the divalent linking group. Y ２１ As Y, a linear aliphatic hydrocarbon group is preferred, a linear alkylene group is more preferred, a linear alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or an ethylene group is particularly preferred. ２２ is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. ２１ -C(=O)-O] ｍ” -Y ２２ In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, ２１ -C(=O)-O] ｍ” -Y ２２ The group represented by - includes the group represented by the formula -Y ２１ -C(=O)-O-Y ２２ Among them, groups represented by the formula -(CH ２ ) ａ’ -C(=O)-O-(CH ２ ) ｂ’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0035] Among them, R ＥＰ The epoxy group-containing group in is preferably a glycidyl group.

[0036] Alternatively, the component (Ap) may suitably be a trifunctional epoxy compound having three epoxy groups in the molecule, such as trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, tris(4-hydroxyphenyl)methane triglycidyl ether, or a trifunctional epoxy compound represented by the following general formula (Ap-2):

[0037] [In formula (Ap-2), R ｐ３ , R ｐ４ and R ｐ５ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ＥＰ is an epoxy group-containing group. ＥＰ may be the same or different from each other.

[0038] In the formula (Ap-2), R ｐ３ , R ｐ４ and R ｐ５ The alkyl group having 1 to 5 carbon atoms is, for example, a linear, branched, or cyclic alkyl group having 1 to 5 carbon atoms. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group, and examples of the cyclic alkyl group include a cyclobutyl group and a cyclopentyl group. Among these, R ｐ３ , R ｐ４ and R ｐ５ Each of the groups is preferably a hydrogen atom or a linear or branched alkyl group, more preferably a hydrogen atom or a linear alkyl group, further preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

[0039] In the formula (Ap-2), Rm ＥＰ is an epoxy group-containing group, and R ＥＰ A glycidyl group is preferred. ＥＰ may be the same as or different from each other.

[0040] Specific examples of the trifunctional epoxy compound represented by formula (Ap-2) are shown below.

[0041]

[0042] The trifunctional epoxy compound may be used alone or in combination of two or more. Among them, as the trifunctional epoxy compound, a compound having a structure in which the distance between three epoxy groups is large within the molecule is preferred from the viewpoint of preventing the intramolecular crosslinking reaction from proceeding, more preferred is tris(4-hydroxyphenyl)methane triglycidyl ether or the trifunctional epoxy compound represented by the above general formula (Ap-2), particularly preferred is the trifunctional epoxy compound represented by the above general formula (Ap-2), and most preferred is the trifunctional epoxy compound represented by the above formula (Ap-2-1).

[0043] Alternatively, the component (Ap) may preferably be a resin having a structural unit represented by the following general formula (anv1):

[0044] [In the formula, R ＥＰ is an epoxy group-containing group. ａ２２ and R ａ２３ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom.

[0045] In the formula (anv1), R ａ２２ , R ａ２３ The alkyl group having 1 to 5 carbon atoms is R ｐ１ , R ｐ２ The alkyl group having 1 to 5 carbon atoms is the same as the alkyl group having 1 to 5 carbon atoms. ａ２２ , R ａ２３ In the formula (anv1), the halogen atom is preferably a chlorine atom or a bromine atom. ＥＰ represents R in the formula (Ap-1). ＥＰ and a glycidyl group is preferred.

[0046] Specific examples of the structural unit represented by the formula (anv1) are shown below.

[0047]

[0048] The component (Ap) may be a resin consisting solely of the structural unit (anv1), or may be a resin containing the structural unit (anv1) in addition to other structural units. Examples of these other structural units include the structural units represented by the following general formulas (anv2) to (anv3).

[0049] [In the formula, R ａ２４ R is a hydrocarbon group which may have a substituent. ａ２５ ~R ａ２６ , R ａ２８ ~R ａ３０ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom. ａ２７ represents an epoxy group-containing group or a hydrocarbon group which may have a substituent.

[0050] In the formula (anv2), R ａ２４ is a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group which may have a substituent include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0051] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, with an isopropyl group being preferred.

[0052] R ａ２４When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As an aliphatic hydrocarbon group that is a monocyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferred. As the monocycloalkane, one having 3 to 6 carbon atoms is preferred, and specific examples thereof include cyclopentane and cyclohexane. As an aliphatic hydrocarbon group that is a polycyclic group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferred, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferred, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0053] R ａ２４ When the cyclic hydrocarbon group of the formula (I) is an aromatic hydrocarbon group, the aromatic 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 having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. R ａ２４Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 or 2, and particularly preferably 1 carbon atom.

[0054] In the formulas (anv2) and (anv3), R ａ２５ ~R ａ２６ , R ａ２８ ~R ａ３０ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom. The alkyl group having 1 to 5 carbon atoms and the halogen atom are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom. ａ２２ , R ａ２３ is the same as:

[0055] In the formula (anv3), R ａ２７ R is an epoxy group-containing group or a hydrocarbon group which may have a substituent. ａ２７ The epoxy group-containing group is R ＥＰ It is the same as R ａ２７ The hydrocarbon group which may have a substituent is R ａ２４ is the same as:

[0056] Specific examples of the structural units represented by the formulae (anv2) to (anv3) are shown below.

[0057]

[0058] When the component (Ap) contains other structural units in addition to the structural unit (anv1), there are no particular limitations on the proportion of each structural unit within the component (Ap), but the total amount of structural units having an epoxy group, relative to the total amount of all structural units constituting the component (Ap), is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, and even more preferably 30 to 70 mol %.

[0059] Examples of commercially available products of component (Ap) include jER-152, jER-154, jER-157S70, and jER-157S65 (all manufactured by Mitsubishi Chemical Corporation), 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, and EPICLON HP5000 (all manufactured by DIC Corporation), and EOCN-1020 (manufactured by Nippon Kayaku Co., Ltd.).

[0060] When the commercially available product described above contains impurities such as low-molecular-weight components in addition to the component (Ap), the component (Ap) obtained by removing the impurities from the commercially available product may be used. The method for removing the impurities is not particularly limited, and any known method may be used. Examples of the method for removing the impurities include washing the commercially available product with a solvent in which only the impurities dissolve, reprecipitation of the component (Ap), fractionation by preparative GPC, fractionation using a dialysis membrane, and the like.

[0061] The molecular weight dispersity (Mw / Mn) of the component (Ap) is preferably 2.0 or more and 4.0 or less, and more preferably 2.0 or more and 3.0 or less.

[0062] The epoxy equivalent of component (Ap) is preferably 200 g / eq. or more and 300 g / eq. or less, and more preferably 200 g / eq. or more and 240 g / eq. or less. The epoxy equivalent of component (Ap) can be measured by potentiometric titration as described in JIS K-7236. Methods for measuring the epoxy equivalent by potentiometric titration include the hydrochloric acid-dioxane method, the perchloric acid-tetraethylammonium bromide method, the perchloric acid-cetyltrimethylammonium bromide method, the hydrochloric acid-potassium iodide method, and the Dubertaki method using a hydrogen bromide-acetic acid solution.

[0063] As the component (Ap), one type may be used alone, or two or more types may be used in combination.

[0064] <Difunctional aromatic epoxy compound (Am) having a molecular weight of 800 or less> As the component (Am), a difunctional aromatic epoxy compound having a molecular weight of 800 or less is used.

[0065] Examples of bifunctional aromatic epoxy compounds having a molecular weight of 800 or less include bisphenol-based diglycidyl ethers such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol E diglycidyl ether, bisphenol Z diglycidyl ether, bisphenol S diglycidyl ether, bisphenol AD ​​diglycidyl ether, bisphenol acetophenone diglycidyl ether, bisphenol trimethylcyclohexane diglycidyl ether, bisphenol fluorene diglycidyl ether, tetramethyl bisphenol A diglycidyl ether, tetramethyl bisphenol F diglycidyl ether, tetra-t-butyl bisphenol A diglycidyl ether, and tetramethyl bisphenol S diglycidyl ether. biphenol diglycidyl ethers such as biphenol diglycidyl ether, tetramethylbiphenol diglycidyl ether, dimethylbiphenol diglycidyl ether, and tetra-t-butylbiphenol diglycidyl ether; benzenediol diglycidyl ethers such as hydroquinone diglycidyl ether, dihydroanthracene diglycidyl ether, methylhydroquinone diglycidyl ether, dibutylhydroquinone diglycidyl ether, resorcinol diglycidyl ether, and methylresorcinol diglycidyl ether; dihydroanthrahydroquinone diglycidyl ether, dihydroxydiphenyl ether diglycidyl ether, thiodiphenol diglycidyl ether, and dihydroxynaphthalene diglycidyl ether.

[0066] Suitable examples of the difunctional aromatic epoxy compound include difunctional epoxy compounds represented by the following general formula (Am-1):

[0067] [In formula (Am-1), R ｐ６ and R ｐ７ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ｐ６ and R ｐ７ and are mutually bonded to form C ＊ and R may form an alicyclic group which may have a substituent. ＥＰis an epoxy group-containing group. ＥＰ may be the same or different from each other.

[0068] In the formula (Am-1), R ｐ６ , R ｐ７ The alkyl group having 1 to 5 carbon atoms is R ｐ１ , R ｐ２ The alkyl group having 1 to 5 carbon atoms is the same as the alkyl group having 1 to 5 carbon atoms. ｐ６ and R ｐ７ and are mutually bonded to form C ＊ In the case where R forms an alicyclic group which may have a substituent, the alicyclic group preferably has 3 to 11 carbon atoms, more preferably 3 to 8 carbon atoms, and even more preferably 3 to 6 carbon atoms. ＥＰ represents R in the formula (Ap-1). ＥＰ and a glycidyl group is preferred.

[0069] In the negative photosensitive composition according to this embodiment, the total content of the component (Ap) and the component (Am) is preferably 70% by mass or more, more preferably 80 to 99% by mass, and even more preferably 85 to 95% by mass, relative to the total mass (100% by mass) of the solid contents of the negative photosensitive composition.

[0070] In the negative-type photosensitive composition according to this embodiment, the content of the component (Am) is 0.6 to 10% by mass, preferably 0.7 to 8.0% by mass, and more preferably 0.8 to 2.0% by mass, relative to the total mass (100% by mass) of the components (Ap) and (Am). When the content of the component (Am) is at least the lower limit of the preferred range, the adhesion of a photosensitive film for forming a top plate portion to the sidewall of the hollow structure is improved during formation of the hollow structure. On the other hand, when the content of the component (Am) is at most the upper limit of the preferred range, a pattern with a good shape and high rectangularity is easily formed during pattern formation.

[0071] In the negative-type photosensitive composition according to this embodiment, the content of the component (Ap) is 90 to 99.4% by mass, preferably 92 to 99.3% by mass, and more preferably 98 to 99.2% by mass, based on the total mass (100% by mass) of the components (Ap) and (Am). When the content of the component (Ap) is at least the lower limit of the above-mentioned preferred range, a pattern with a good shape and high rectangularity is likely to be formed during pattern formation. On the other hand, when the content of the component (Ap) is at most the upper limit of the above-mentioned preferred range, when forming a hollow structure, the photosensitive film for forming the top plate portion is likely to be attached more easily to the sidewall of the hollow structure.

[0072] Other Epoxy Group-Containing Compounds In the negative photosensitive composition of this embodiment, in addition to the component (Ap) and the component (Am), other epoxy group-containing compounds may be used. Examples of other epoxy group-containing compounds include bisphenol epoxy resins (bisphenol A epoxy resins, bisphenol F epoxy resins), acrylic resins, and aliphatic epoxy resins.

[0073] Examples of bisphenol-type epoxy resins include epoxy resins represented by the following general formula (abp1).

[0074] [In the formula, R ＥＰ is an epoxy group-containing group, and R ａ３１ , R ａ３２ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, ３１ is an integer from 1 to 50.

[0075] In formula (abp1), R ａ３１ , R ａ３２ The alkyl group having 1 to 5 carbon atoms is R ｐ１ , R ｐ２ The alkyl groups having 1 to 5 carbon atoms are the same as those in the above. ａ３１ , R ａ３２ is preferably a hydrogen atom or a methyl group. ＥＰ represents R in the formula (Ap-1). ＥＰ and a glycidyl group is preferred.

[0076] Examples of the acrylic resin include resins having epoxy group-containing units represented by the following general formulas (a1-1) and (a1-2).

[0077] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ４１ represents a divalent hydrocarbon group which may have a substituent. ４１ is an integer from 0 to 2. ａ４１ , R ａ４２ is an epoxy group-containing group. ４２ is 0 or 1. ４１ Is (na ４３ +1)valent aliphatic hydrocarbon group. ４３ is an integer of 1 to 2.

[0078] In the formula (a1-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms represented by R is preferably linear or branched, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms represented by R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom 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, and from the perspective of industrial availability, a hydrogen atom or a methyl group is most preferred.

[0079] In the formula (a1-1), Va ４１ is a divalent hydrocarbon group which may have a substituent, and R in the formula (Ap-1) ＥＰ Examples of the divalent hydrocarbon group which may have a substituent include the same groups as those described in the above. ４１The hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably a linear or branched aliphatic hydrocarbon group, still more preferably a linear aliphatic hydrocarbon group, and particularly preferably a linear alkylene group.

[0080] In formula (a1-1), na ４１ is an integer of 0 to 2, preferably 0 or 1.

[0081] In formulas (a1-1) and (a1-2), R ａ４１ , R ａ４２ is an epoxy group-containing group, and R ＥＰ is the same as:

[0082] In formula (a1-2), Wa ４１ In (na ４３ The (+1)-valent aliphatic hydrocarbon group means a hydrocarbon group that is not aromatic and may be saturated or unsaturated, but is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in their structure, and groups that combine linear or branched aliphatic hydrocarbon groups with aliphatic hydrocarbon groups containing a ring in their structure.

[0083] Furthermore, the acrylic resin in component (A) may contain structural units derived from other polymerizable compounds in order to appropriately control the physical and chemical properties. Examples of such polymerizable compounds include known radically polymerizable compounds and anionically polymerizable compounds. Examples of such polymerizable compounds include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; hydroxypropyl acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl ... (meth)acrylic acid aryl esters such as phenyl (meth)acrylate and benzyl (meth)acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; vinyl group-containing aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; and amide bond-containing polymerizable compounds such as acrylamide and methacrylamide.

[0084] Furthermore, suitable examples of other epoxy group-containing compounds include compounds represented by the following general formula (m-01) (hereinafter, this compound may also be referred to as "component (m01)").

[0085] [In the formula, R ＥＰ is an epoxy group-containing group. ＥＰ may be the same or different from each other.

[0086] In the formula (m-01), R ＥＰ is an epoxy group-containing group, and R ＥＰ is the same as:

[0087] Examples of commercially available products that can be used as the component (m01) include the TEPIC series (manufactured by Nissan Chemical Industries, Ltd.), such as TEPIC, TEPIC-VL, TEPIC-PAS, TEPIC-G, TEPIC-S, TEPIC-SP, TEPIC-SS, TEPIC-HP, TEPIC-L, TEPIC-FL, and TEPIC-UC; MA-DGIC, DA-MGIC, and TOIC (manufactured by Shikoku Chemical Industries, Ltd.).

[0088] The component (m01) may be used alone or in combination of two or more. In the negative photosensitive composition used in this embodiment, the content of the component (m01) is preferably 1 to 15 parts by mass, and more preferably 3 to 10 parts by mass, relative to 100 parts by mass of the total parts by mass of the component (P0).

[0089] Suitable examples of other epoxy group-containing compounds include compounds having a structure represented by the following general formula (m-02) (hereinafter, this compound may be referred to as "component (m02)"). The component (m02) may form a fused ring.

[0090] [In the formula, n ２ is an integer from 1 to 4.

[0091] In the formula (m-02), n ２ is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2.

[0092] Examples of the (m02) component include compounds in which a plurality of partial structures represented by the general formula (m-02) are bonded via a divalent linking group or a single bond. Among these, compounds in which a plurality of partial structures represented by the general formula (m-02) are bonded via a divalent linking group are preferred. The divalent linking group here is not particularly limited, but preferred examples include divalent hydrocarbon groups which may have a substituent and divalent linking groups which contain a heteroatom. The divalent hydrocarbon groups which may have a substituent and divalent linking groups which contain a heteroatom here are the same as R in the above formula (Ap-1). ＥＰ The divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom which are described in (epoxy group-containing group) are the same as those described above. Among these, the divalent linking group containing a hetero atom is preferred. ２１ a group represented by —C(═O)—O—, —C(═O)—O—Y ２１ A group represented by - is more preferred. ２１ As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred.

[0093] Examples of the component (m02) include compounds represented by the following chemical formula: In the formula, l represents an integer of 1 to 10, and m represents an integer of 1 to 30. R represents an alkylene group having 1 to 8 carbon atoms (preferably an alkylene group having 1 to 3 carbon atoms, such as a methylene group, an ethylene group, a propylene group, or an isopropylene group). n1 and n2 each represent an integer of 1 to 30.

[0094]

[0095] Examples of commercially available products that can be used as the component (m02) include Celloxide 2021P, Celloxide 2081, Celloxide 2083, Celloxide 2085, Celloxide 8000, and Celloxide 8010 (all manufactured by Daicel Corporation); Epocalic THI-DE, Epocalic THI-DE-102, and Epocalic THI-DE-103 (all manufactured by ENEOS Corporation); and the like.

[0096] The component (m02) may be used alone or in combination of two or more. In the negative photosensitive composition used in this embodiment, the content of the component (m02) is preferably 1 to 20 parts by mass, and more preferably 5 to 15 parts by mass, relative to 100 parts by mass of the total parts by mass of the components (Ap) and (Am).

[0097] Examples of aliphatic epoxy resins include hydrogenated bisphenol A glycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, and 1,4-cyclohexanedimethanol diglycidyl ether.

[0098] <Cationic Polymerization Initiator> The cationic polymerization initiator (hereinafter also referred to as "component (I)") contained in the negative photosensitive composition of this embodiment is a compound that generates cations when irradiated with active energy rays such as ultraviolet rays, far ultraviolet rays, excimer laser light such as KrF or ArF, X-rays, electron beams, etc., and the cations can serve as polymerization initiators. Examples of the component (I) include onium borate salts (hereinafter also referred to as "component (I1)") and cationic polymerization initiators other than component (I1) (other cationic polymerization initiators).

[0099] <<Onium Borate Salt>> Onium borate salt (component (I1)) generates a relatively strong acid upon exposure. Therefore, by forming a pattern using a negative photosensitive composition containing component (I1), sufficient sensitivity can be obtained, resulting in the formation of a good pattern. Furthermore, the use of component (I1) also reduces the risk of toxicity and metal corrosion. Suitable examples of component (I1) include compounds represented by the following general formula (I1):

[0100] [In the formula, R ｂ０１ ~R ｂ０４ are each independently an aryl group which may have a substituent, or a fluorine atom; q is an integer of 1 or more; ｑ＋ is a q-valent organic cation.

[0101] Anion part In the formula (I1), R ｂ０１ ~R ｂ０４ The aryl group in R preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples include naphthyl, phenyl, and anthracenyl groups, with the phenyl group being preferred because of its ease of availability. ｂ０１ ~R ｂ０４ The aryl group in formula (I1) may have a substituent. The substituent is not particularly limited, but is preferably a halogen atom, a hydroxyl group, an alkyl group (preferably a linear or branched alkyl group, preferably having 1 to 5 carbon atoms), or a halogenated alkyl group, more preferably a halogen atom or a halogenated alkyl group having 1 to 5 carbon atoms, and particularly preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. When the aryl group has a fluorine atom, the polarity of the anion moiety is increased, which is preferable. Among these, R in formula (I1) ｂ０１ ~R ｂ０４ As each of the groups, a fluorinated phenyl group is preferred, and a perfluorophenyl group is particularly preferred.

[0102] A preferred example of the anion moiety of the compound represented by formula (I1) is tetrakis(pentafluorophenyl)borate ([B(C ６ F ５ ) ４ ] － tetrakis[(trifluoromethyl)phenyl]borate ([B(C ６ H ４ CF ３ ) ４ ] － ); difluorobis(pentafluorophenyl)borate ([(C ６ F ５ ) ２ BF ２ ] － ); trifluoro(pentafluorophenyl)borate ([(C ６ F ５ ) BF ３ ] － tetrakis(difluorophenyl)borate ([B(C ６ H３ F ２ ) ４ ] － Among them, tetrakis(pentafluorophenyl)borate ([B(C ６ F ５ ) ４ ] － ) is particularly preferred.

[0103] Cation moiety In the formula (I1), Q ｑ＋ Suitable examples of the cation include sulfonium cations and iodonium cations, and the organic cations represented by the following general formulae (ca-1) to (ca-5) are particularly preferred.

[0104] [In the formula, R ２０１ ~R ２０７ , and R ２１１ ~R ２１２ R each independently represents an aryl group, a heteroaryl group, an alkyl group, or an alkenyl group, which may have a substituent. ２０１ ~R ２０３ , R ２０６ ~R ２０７ , R ２１１ ~R ２１２ may be bonded to each other to form a ring together with the sulfur atom in the formula. ２０８ ~R ２０９ R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ２１０ represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group. ２０１ represents —C(═O)— or —C(═O)—O—. ２０１ each independently represents an arylene group, an alkylene group, or an alkenylene group; x is 1 or 2. ２０１ represents a (x+1)-valent linking group.

[0105] R ２０１ ~R ２０７ , and R ２１１ ~R ２１２The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２０１ ~R ２０７ , and R ２１１ ~R ２１２ Examples of the heteroaryl group in the formula (I) include those in which some of the carbon atoms constituting the aryl group have been substituted with heteroatoms. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of this heteroaryl group include a group in which one hydrogen atom has been removed from 9H-thioxanthene; and examples of the substituted heteroaryl group include a group in which one hydrogen atom has been removed from 9H-thioxanthen-9-one. R ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２０１ ~R ２０７ , and R ２１０ ~R ２１２ Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an oxo group (═O), an aryl group, and groups represented by the following formulas (car-r-1) to (car-r-10):

[0106] [In the formula, R' ２０１ are each independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0107] In the above formulae (car-r-1) to (car-r-10), R' ２０１ are each independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0108] Optionally substituted cyclic group: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or a cyclic aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0109] R' ２０１ The aromatic hydrocarbon group in R' is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. ２０１ Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group in R' include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms, or rings in which some of the hydrogen atoms constituting these aromatic rings or aromatic heterocycles are substituted with oxo groups or the like. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. ２０１ Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic ring (an aryl group: for example, a phenyl group, a naphthyl group, or an anthracenyl group), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group), a group in which one hydrogen atom has been removed from a ring in which some of the hydrogen atoms constituting the aromatic ring have been substituted with an oxo group or the like (for example, anthraquinone), and a group in which one hydrogen atom has been removed from an aromatic heterocycle (for example, 9H-thioxanthene or 9H-thioxanthen-9-one). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2, and particularly preferably 1.

[0110] R' ２０１ Examples of the cyclic aliphatic hydrocarbon group in the formula (I) include aliphatic hydrocarbon groups containing a ring within their structure. Examples of aliphatic hydrocarbon groups containing a ring within their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed within a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group. Preferred monocyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a monocycloalkane. Preferred monocycloalkanes have 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Preferred polycyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a polycyclic skeleton of a fused ring system, such as a cyclic group having a steroid skeleton.

[0111] Among them, R' ２０１ The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0112] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ )２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, —CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0113] A chain alkyl group which may have a substituent: R' ２０１ The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specific examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, heneicosyl, and docosyl groups. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0114] A chain alkenyl group which may have a substituent: R' ２０１ The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl, propenyl (allyl), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, and 2-methylpropenyl groups. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0115] R' ２０１ Examples of the substituent in the cyclic group, chain alkyl group or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, an oxo group, the above-mentioned R' ２０１ Examples of the groups include a cyclic group, an alkylcarbonyl group, and a thienylcarbonyl group.

[0116] Among them, R' ２０１ is preferably a cyclic group which may have a substituent, or a chain alkyl group which may have a substituent.

[0117] R ２０１ ~R ２０３ , R ２０６ ~R ２０７ , R ２１１ ~R ２１２ When they are bonded to each other to form a ring together with the sulfur atom in the formula, they are not substituted with heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or with carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0118] In the formula (ca-3), R ２０８ ~R ２０９ each independently represents 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, and when they are alkyl groups, they may be bonded to each other to form a ring.

[0119] In the formula (ca-3), R ２１０represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group. ２１０ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２１０ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms.

[0120] In the formulas (ca-4) and (ca-5), Y ２０１ each independently represents an arylene group, an alkylene group, or an alkenylene group. ２０１ The arylene group in ２０１ Examples of the aromatic hydrocarbon group in the above formula include groups in which one hydrogen atom has been removed from the aryl groups exemplified in the formula Y. ２０１ The alkylene group and alkenylene group in R' ２０１ Examples of the chain alkyl group and chain alkenyl group include groups in which one hydrogen atom has been removed from the groups exemplified above as the chain alkyl group and chain alkenyl group.

[0121] In the formulas (ca-4) and (ca-5), x is 1 or 2. ２０１ is a (x+1)-valent linking group, i.e., a divalent or trivalent linking group. ２０１ The divalent linking group in the formula (Ap-1) is preferably a divalent hydrocarbon group which may have a substituent. ＥＰ The same groups as the optionally substituted divalent hydrocarbon groups exemplified by W are preferred. ２０１ The divalent linking group in may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group, or a group consisting of only an arylene group is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferred. ２０１ The trivalent linking group in ２０１Examples of the divalent linking group include a group in which one hydrogen atom has been removed from the divalent linking group shown in the formula: and a group in which the divalent linking group is further bonded to the divalent linking group shown in the formula: ２０１ The trivalent linking group in the formula (I) is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0122] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-24).

[0123]

[0124] [In the formula, R” ２０１ is a hydrogen atom or a substituent. The substituent includes the above-mentioned R ２０１ ~R ２０７ and R ２１０ ~R ２１２ The substituents are the same as those exemplified as the substituents that may be possessed by

[0125] As the cation represented by the formula (ca-1), cations represented by the following general formulae (ca-1-25) to (ca-1-35) are also preferred.

[0126]

[0127] [In the formula, R' ２１１ is an alkyl group. ｈａｌ is a hydrogen atom or a halogen atom.

[0128] As the cation represented by the formula (ca-1), cations represented by the following chemical formulas (ca-1-36) to (ca-1-48) are also preferred.

[0129]

[0130] As the cation represented by the formula (ca-1), cations having a benzoylphenyl group represented by the following chemical formulas (ca-1-49) to (ca-1-54) are also preferred.

[0131]

[0132] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0133] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0134]

[0135] Specific examples of suitable cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0136]

[0137] As the cation represented by the formula (ca-5), cations represented by the following general formulas (ca-5-1) to (ca-5-3) are also preferred.

[0138] [In the formula, R' ２１２ is an alkyl group or a hydrogen atom. ２１１ is an alkyl group.

[0139] Among the above, the cation part [(Q ｑ＋ ) １／ｑ is preferably a cation represented by general formula (ca-1), more preferably a cation represented by each of formulas (ca-1-1) to (ca-1-54), and even more preferably a cation represented by each of formulas (ca-1-49) to (ca-1-54).

[0140] <<Other Cationic Polymerization Initiators>> Examples of cationic polymerization initiators other than the component (I1) include compounds represented by the following general formula (I2-1) or (I2-2) (hereinafter referred to as “component (I2)”); and compounds represented by the following general formula (I3-1) or (I3-2) (hereinafter referred to as “component (I3)”).

[0141] Regarding the component (I2): The component (I2) is a compound represented by the following general formula (I2-1) or (I2-2): The component (I2) generates a relatively strong acid upon exposure. Therefore, when a pattern is formed using a negative-working photosensitive composition containing the component (I), sufficient sensitivity is obtained and a good pattern is formed.

[0142] [In the formula, R ｂ０５ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０５ may be the same or different from each other. q is an integer of 1 or more, and Q ｑ＋ is a q-valent organic cation.

[0143] [In the formula, R ｂ０６ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０６ may be the same or different from each other. q is an integer of 1 or more, and Q ｑ＋ is a q-valent organic cation.

[0144] Anion part In the formula (I2-1), R ｂ０５ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０５ may be the same or different. ｂ０５ The fluorinated alkyl group in the formula (I) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms. Specific examples include alkyl groups having 1 to 5 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms. ｂ０５ As the alkyl group, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms is more preferred, and a fluorine atom, a trifluoromethyl group or a pentafluoroethyl group is even more preferred.

[0145] The anion moiety of the compound represented by formula (I2-1) is preferably represented by the following general formula (b0-2a).

[0146] [In the formula, R ｂｆ０５ represents a fluorinated alkyl group which may have a substituent. １ is an integer from 1 to 5.

[0147] In formula (b0-2a), R ｂｆ０５ The optionally substituted fluorinated alkyl group in R ｂ０５ In formula (b0-2a), nb is the same as the optionally substituted fluorinated alkyl group listed above. １ is preferably an integer of 1 to 4, more preferably an integer of 2 to 4, and most preferably 3.

[0148] In the formula (I2-2), R ｂ０６ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０６ may be the same or different. ｂ０６ The fluorinated alkyl group in the formula (I) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms. Specific examples include alkyl groups having 1 to 5 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms. ｂ０６ As the alkyl group, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms is more preferred, and a fluorine atom is even more preferred.

[0149] In formula (I2-1) and formula (I2-2), q is an integer of 1 or more, and Q ｑ＋ is a q-valent organic cation. ｑ＋ As the group, Q in the above formula (I1) ｑ＋ Among them, cations represented by general formula (ca-1) are preferred, and cations represented by formulas (ca-1-1) to (ca-1-54) are more preferred.

[0150] Regarding the component (I3): The component (I3) is a compound represented by the following general formula (I3-1) or (I3-2).

[0151] [In the formula, R ｂ１１ ~R ｂ１２is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom. m is an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

[0152] {Component (I3-1)} Anion portion In formula (I3-1), R ｂ１２ is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom, and is ２０１ Among the cyclic groups, chain alkyl groups, and chain alkenyl groups in the explanation of R, those which have no substituent or have a substituent other than a halogen atom are exemplified. ｂ１２ is preferably a chain alkyl group which may have a substituent other than a halogen atom, or an aliphatic cyclic group which may have a substituent other than a halogen atom. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent other than a halogen atom); or a group in which one or more hydrogen atoms have been removed from camphor, etc. ｂ１２ The hydrocarbon group may have a substituent other than a halogen atom, and examples of the substituent include R ｂ１１ Examples include the same substituents other than halogen atoms as those which may be possessed by the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in (1). Here, the phrase "may have a substituent other than halogen atoms" not only excludes cases in which a substituent consisting of only halogen atoms is possessed, but also excludes cases in which a substituent containing at least one halogen atom is possessed (for example, cases in which the substituent is a fluorinated alkyl group, etc.).

[0153] Specific examples of preferred anion moieties of the component (I3-1) are shown below.

[0154]

[0155] Cation moiety In formula (I3-1), M ｍ＋ is an m-valent organic cation. ｍ＋ Suitable examples of the organic cation include the same cations as those represented by the general formulas (ca-1) to (ca-5) above, and among these, the cation represented by the general formula (ca-1) above is more preferred. ２０１ , R ２０２ , R ２０３ A sulfonium cation in which at least one of the groups is an organic group having 16 or more carbon atoms (aryl group, heteroaryl group, alkyl group, or alkenyl group) which may have a substituent is particularly preferred, as it improves resolution and roughness characteristics. The substituent that the organic group may have is the same as above, and examples thereof include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an oxo group (═O), an aryl group, and groups represented by the above formulas (car-r-1) to (car-r-10). The number of carbon atoms in the organic group (aryl group, heteroaryl group, alkyl group, or alkenyl group) is preferably 16 to 25, more preferably 16 to 20, and particularly preferably 16 to 18, and such M ｍ＋ Suitable examples of the organic cation include the 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), and among these, the cation represented by the above formula (ca-1-29) is particularly preferred.

[0156] {Component (I3-2)} Anion portion In formula (I3-2), R ｂ１１ is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom, and is ２０１Among the cyclic groups, chain alkyl groups and chain alkenyl groups in the explanation of (1), those which have no substituent or those which have a substituent other than a halogen atom are exemplified.

[0157] Among these, R ｂ１１ is preferably an aromatic hydrocarbon group which may have a substituent other than a halogen atom, an aliphatic cyclic group which may have a substituent other than a halogen atom, or a chain alkyl group which may have a substituent other than a halogen atom. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a lactone-containing cyclic group, an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the following general formulas (y-al-1) to (y-al-7). In the following general formulas (y-al-1) to (y-al-7), R in the above formula (I3-2) ｂ１１ The bond to V' in the following general formulae (y-al-1) to (y-al-7) is １０１ is.

[0158] [In the formula, V' １０１ is a single bond or an alkylene group having 1 to 5 carbon atoms. １０２ is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0159] V' １０２ The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0160] V' １０１ and V' １０２ The alkylene group in V' may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group. １０１ and V' １０２ Specific examples of the alkylene group in ２ -]; -CH(CH ３) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; ethylene groups [-CH ２ CH ２ -]; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, etc.; a trimethylene group (n-propylene group) [—CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ an alkyltrimethylene group such as -; a tetramethylene group [-CH ２ CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ -, etc.; an alkyltetramethylene group such as a pentamethylene group [—CH ２ CH ２ CH ２ CH ２ CH ２ -]. Also, V'１０１ or V' １０２ In the above formula, some methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by R' ２０１ A divalent group obtained by further removing one hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group) of the above formula (I) is preferred, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferred.

[0161] The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group. The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched 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 groups.

[0162] R ｂ１１ is preferably a cyclic group which may have a substituent other than a halogen atom. Specific examples of preferred anion moieties of component (I3-2) are shown below.

[0163]

[0164] Cation moiety In formula (I3-2), M ｍ＋ is an m-valent organic cation, and M in the formula (I3-1) ｍ＋ is the same as:

[0165] Furthermore, from the viewpoints of increasing the elasticity of the photosensitive film and facilitating the formation of a fine structure without residue, component (I) is preferably a cationic polymerization initiator that generates an acid with a pKa (acid dissociation constant) of -5 or less upon exposure. By using a cationic polymerization initiator that generates an acid with a pKa of more preferably -6 or less, and even more preferably -8 or less, high sensitivity to exposure can be achieved. The lower limit of the pKa of the acid generated by component (I) is preferably -15 or more. By using a cationic polymerization initiator that generates an acid with such a suitable pKa, high sensitivity can be achieved. Here, "pKa (acid dissociation constant)" refers to a commonly used index indicating the acid strength of a target substance. Note that the pKa in this specification is a value measured at a temperature of 25°C. The pKa value can be determined by known measurement techniques. Alternatively, values ​​calculated using known software such as "ACD / Labs" (trade name, manufactured by Advanced Chemistry Development Co.) can also be used.

[0166] As the component (I), one type may be used alone, or two or more types may be used in combination. In the negative photosensitive composition used in this embodiment, the component (I) is preferably at least one type selected from the group consisting of the component (I1), the component (I2), and the component (I3), and it is more preferable to use the component (I1).

[0167] In the negative-tone photosensitive composition used in this embodiment, the content of component (I) is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, even more preferably 0.15 to 3 parts by mass, and particularly preferably 0.2 to 1 part by mass, based on 100 parts by mass of the total parts by mass of component (Ap) and component (Am). When the content of component (I) is at least the lower limit of the preferred range, sufficient sensitivity is obtained, and the lithography properties of the pattern are further improved. In addition, the strength of the photosensitive film is further increased. On the other hand, when the content is at most the upper limit of the preferred range, sensitivity is appropriately controlled, and a pattern with a good shape is more likely to be obtained.

[0168] <Other Components> The negative photosensitive composition of this embodiment may contain other components as needed in addition to the above-described components (Ap), (Am), and (I). If desired, the negative photosensitive composition of this embodiment may appropriately contain miscible additives, such as epoxy group-containing compounds other than the components (Ap) and (Am), silane coupling agents, sensitizer components, metal oxides (M), solvents, additional resins for improving film performance, dissolution inhibitors, basic compounds, plasticizers, stabilizers, colorants, and antihalation agents.

[0169] Silane coupling agents can be used as adhesion aids to improve adhesion to substrates. Examples of silane coupling agents include silane coupling agents having reactive substituents such as carboxy groups, methacryloyl groups, isocyanate groups, and epoxy groups. Specific examples include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. One type of silane coupling agent may be used alone, or two or more types may be used in combination. When a silane coupling agent is included, its content is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 3 parts by mass, per 100 parts by mass of component (P0). When the content of the silane coupling agent is within the above-mentioned preferred range, the strength of the cured film is further increased. Additionally, the adhesion between the cured film and the substrate is further strengthened.

[0170] The sensitizer component is not particularly limited as long as it is capable of absorbing energy due to exposure and transmitting that energy to another substance. Specific examples of the sensitizer component that can be used include benzophenone-based photosensitizers such as benzophenone and 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 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, and 9-ethoxyanthracene; and known photosensitizers such as biacetyl, eosin, rose bengal, pyrene, phenothiazine, and anthrone. One type of sensitizer component may be used alone, or two or more types may be used in combination. When a sensitizer component is included, its content is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of component (P0). When the content of the sensitizer component is within the above-mentioned preferred range, sensitivity and resolution can be further improved.

[0171] The negative photosensitive composition of this embodiment may further contain a metal oxide (M) (hereinafter also referred to as "component (M)"), since this facilitates the formation of a cured film with enhanced strength. Furthermore, the inclusion of component (M) enables the formation of a highly shaped, high-resolution pattern. Examples of component (M) include oxides of metals such as silicon (metallic silicon), titanium, zirconium, and hafnium. Among these, silicon oxide is preferred, and silica is particularly preferred. Furthermore, component (M) is preferably in the form of particles. Such a particulate component (M) is preferably composed of particles having a volume average particle diameter of 5 to 40 nm, more preferably of 5 to 30 nm, and even more preferably of 10 to 20 nm. When the volume average particle diameter of component (M) is equal to or greater than the lower limit of the preferred range, the strength of the cured film is likely to be enhanced. On the other hand, when the content is equal to or less than the upper limit of the preferred range, residues are less likely to be generated during pattern formation, making it easier to form higher-resolution patterns. In addition, the transparency of the photosensitive film is improved. The particle size of component (M) can be appropriately selected depending on the exposure light source. It is generally believed that particles having a particle size of 1 / 10 or less of the wavelength of light are virtually immune to the effects of light scattering. For this reason, when forming a microstructure by photolithography using i-line (365 nm), for example, it is preferable to use particles (particularly preferably silica particles) having a primary particle size (volume average) of 10 to 20 nm as component (M). One type of component (M) may be used alone, or two or more types may be used in combination. When component (M) is included, its content is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, per 100 parts by mass of component (P0). When component (M) is included, its content is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, per 100 parts by mass of component (P0). When component (M) is included, its content is preferably equal to or greater than the lower limit of the preferred range, making it possible to further increase the strength of the cured film. On the other hand, when it is equal to or less than the upper limit of the above-mentioned preferred range, the transparency of the photosensitive film is further improved.

[0172] The negative photosensitive composition of this embodiment may further contain a solvent (hereinafter sometimes referred to as "component (S)"). Examples of component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; monoalkyl ethers or monoalkyl ethers of the polyhydric alcohols or the compounds having an ester bond such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether; Examples of the solvent include derivatives of polyhydric alcohols such as compounds having an ether bond, such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME), cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate, aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). The component (S) may be used alone or as a mixed solvent of two or more.

[0173] When the component (S) is contained, the amount used is not particularly limited and is set appropriately depending on the coating film thickness at a concentration that allows the negative photosensitive composition to be applied to a substrate or the like without dripping. For example, the component (S) can be used so that the solids concentration is 70% by mass or more, or 60% by mass or more. In addition, an embodiment that does not substantially contain the component (S) (i.e., an embodiment in which the solids concentration is 100% by mass) can also be employed.

[0174] The negative-type photosensitive composition according to the present embodiment described above contains a trifunctional or higher polyfunctional epoxy compound (Ap) and a difunctional aromatic epoxy compound (Am) having a molecular weight of 800 or less, and the content of the (Am) component is 0.6 to 10 mass% relative to the total content (100 mass%) of the (Ap) and (Am) components. Because the negative-type photosensitive composition according to the present embodiment contains a predetermined amount of the (Ap) component, its solubility is likely to decrease upon exposure. Furthermore, because the negative-type photosensitive composition contains a predetermined amount of the (Am) component, its flowability is likely to be increased. Due to these synergistic effects, the negative-type photosensitive composition according to the present embodiment can form a pattern with a good shape and can improve its adherence to the sidewall of a hollow structure.

[0175] (Photosensitive Resist Film) The photosensitive resist film according to this embodiment is obtained by laminating, in this order, a photosensitive film formed using the photosensitive composition according to the above-described embodiment and a cover film on a base film.

[0176] The photosensitive resist film according to this embodiment can be produced, for example, by applying the photosensitive composition according to the above-described embodiment to a substrate film, drying the composition to form a photosensitive film, and then laminating a cover film on the photosensitive film. The photosensitive composition can be applied to the substrate film by an appropriate method using a blade coater, lip coater, comma coater, film coater, or the like. The thickness of the photosensitive film is preferably 100 μm or less, and more preferably 5 to 50 μm.

[0177] The substrate film may be a known film, such as a thermoplastic resin film. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate. The thickness of the substrate film is preferably 2 to 150 μm.

[0178] Known cover films can be used, such as polyethylene film and polypropylene film. A cover film having a lower adhesive strength with the photosensitive film than the base film is preferred. The thickness of the cover film is preferably 2 to 150 μm, more preferably 2 to 100 μm, and even more preferably 5 to 50 μm. The base film and cover film may be made of the same film material, or different film materials.

[0179] (Method for manufacturing hollow structure) The method for manufacturing a hollow structure according to this embodiment is a method for manufacturing a hollow structure comprising a recess and a top plate portion that covers the opening of the recess, and the top plate portion is formed using the above-mentioned negative photosensitive composition. FIG. 1 is a schematic diagram illustrating the method for manufacturing a hollow structure according to this embodiment. The illustrated method for manufacturing a hollow structure includes a step of forming a side wall on a substrate (first step (S1)), and a step of forming a top plate portion on the side wall to produce the hollow structure (second step (S2)). The first step (S1) and the second step (S2) will be described in detail below.

[0180] [First Step (S1)] In the first step, sidewalls 20 are formed on the substrate 10 to obtain the substrate 10 having a recess 15 on its surface. In [First Step] of Fig. 1 , the substrate 10 having the recess 15 on its surface is illustrated, which is formed by the substrate 10 and the sidewalls 20 formed on the substrate 10.

[0181] <<Regarding the Substrate Having a Recess on its Surface>> Examples of the substrate 10 having a recess 15 on its surface include a structure in which a pattern is formed on the substrate 10, a stepped substrate, and the like. The recess 15 may be made of either an organic or inorganic material. Such a substrate 10 having a recess 15 on its surface can be manufactured, for example, by a method including the steps of: forming a photosensitive film on a support using a negative photosensitive composition (hereinafter referred to as the "film formation step"); exposing the photosensitive film (hereinafter referred to as the "exposure step"); and developing the exposed photosensitive film with a developer containing an organic solvent to form a negative pattern that becomes the sidewall 20 of the recess 15 (hereinafter referred to as the "development step"). The method for manufacturing such a substrate 10 having a recess 15 on its surface can be performed as follows.

[0182] Film formation step: First, a negative photosensitive composition is applied onto a support by a known method such as spin coating, roll coating, or screen printing, and then baked (post-applied bake (PAB)) for 2 to 60 minutes at a temperature of 50 to 150° C. to form a photosensitive film. Note that the film formation step can also be performed by disposing a photosensitive composition layer, which has been previously prepared using a negative photosensitive composition, on the support.

[0183] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, substrates for electronic components include silicon, silicon nitride, titanium, tantalum, and lithium tantalate (LiTaO ３ ), niobium, lithium niobate (LiNbO ３ Examples of suitable materials include metal substrates such as palladium, titanium tungsten, copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0184] The thickness of the photosensitive film formed from the negative photosensitive composition is not particularly limited, but is preferably about 10 to 100 μm.

[0185] Exposure Step: Next, the formed photosensitive film is selectively exposed using a known exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by drawing by direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) as needed, for example, at a temperature of 80 to 150° C. for 40 to 1200 seconds, preferably 40 to 1000 seconds, and more preferably 60 to 900 seconds.

[0186] The wavelength used for exposure is not particularly limited, and radiation such as ultraviolet light having a wavelength of 300 to 500 nm, i-rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). Examples of radiation sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and argon gas lasers. Here, radiation refers to ultraviolet light, visible light, far ultraviolet light, X-rays, electron beams, and the like. The radiation dose varies depending on the type and amount of each component in the composition, the thickness of the coating film, and the like, but for example, when an ultra-high-pressure mercury lamp is used, it is 100 to 2000 mJ / cm. ２ is.

[0187] The exposure method for the photosensitive film may be a normal exposure (dry exposure) carried out in air or an inert gas such as nitrogen, or may be liquid immersion exposure (liquid immersion lithography).

[0188] Development step: Next, the exposed photosensitive film is developed with a developer containing an organic solvent (organic developer). After development, a rinse treatment is preferably performed. If necessary, a bake treatment (post-bake) may be performed.

[0189] The organic solvent contained in the organic developer can be appropriately selected from known organic solvents, and specific examples thereof include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents.

[0190] 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, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0191] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, 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 monoethyl ether acetate, diethylene glycol monophenyl 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, Pyrene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 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, milk Examples of the alkyl esters include ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.Among these, butyl acetate or PGMEA is preferred as the ester solvent.

[0192] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0193] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, but examples include ionic and nonionic fluorine-based and / or silicon-based surfactants. Nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is blended, the blending amount is typically 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, based on the total amount of the organic developer.

[0194] The development process can be carried out by a known development method, for example, a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method), etc.

[0195] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method. Examples of the rinse treatment method include a method in which the rinse solution is continuously applied onto a support rotating at a constant speed (spin coating method), a method in which the support is immersed in the rinse solution for a certain period of time (dip method), and a method in which the rinse solution is sprayed onto the surface of the support (spray method). For the rinse treatment, it is preferable to use a rinse solution containing an organic solvent.

[0196] The above-described film formation process, exposure process, and development process can produce a substrate 10 (a structure with a pattern formed on a substrate, a stepped substrate) having a recess 15 on its surface. The thickness (dimension horizontal to the support) and height (dimension vertical to the support) of the sidewall 20 can be set appropriately based on the size of the hollow portion, which is determined depending on the type of electronic device to be accommodated in the recess 15.

[0197] [Second Step (S2)] In the second step of this embodiment, the hollow structure is fabricated by forming an exposed portion 30A, which will become a top plate portion, on the side wall 20 formed in the first step. The second step of this embodiment includes the following steps (i), (ii), (iii), (iv), and (v).

[0198] Step (i): A step of arranging a photosensitive resist film 30F so that the photosensitive resist film 30F covers the opening surface of the recess 15 formed by the sidewall 20 and the substrate 10, and peeling off the base film from the photosensitive film 30 constituting the photosensitive resist film 30F. Step (ii): A step of exposing the photosensitive film 30 after the step (i). Step (iii): A step of performing a heat treatment on the photosensitive film 30 after the step (ii). Step (iv): A step of developing the photosensitive film 30 after the step (iii), to form a negative pattern (exposed portion 30A) that covers the opening surface of the recess 15 formed by the sidewall 20 and the substrate 10 in the substrate 10 having the recess 15 on its surface prepared in the first step (S1). Step (v): A step of further hardening the negative pattern (exposed portion 30A) after step (iv) by heat treatment to obtain a hollow structural body 100 in which the exposed portion 30A, which becomes the top plate portion, is made of the hardened body 40 of the photosensitive film.

[0199] The hollow structure manufactured by the manufacturing method according to this embodiment comprises a recess 15 and a top plate portion that closes the opening of the recess 15. The hollow structure can be suitably used for hollow packages used in SAW filters, MEMS, various sensors, etc.

[0200] <<Photosensitive Resist Film>> The photosensitive resist film 30F in this embodiment has, for example, a negative photosensitive film 30 formed from the above-described negative photosensitive composition.

[0201] When a photosensitive film 30 is formed using this photosensitive resist film 30F and selectively exposed to light, the cationic moiety of component (I) decomposes in the exposed portion 30A of the photosensitive film 30, generating an acid. The acid then causes ring-opening polymerization of the epoxy groups in component (A). As a result, the solubility of component (A) in a developer containing an organic solvent decreases in the exposed portion 30A of the photosensitive film 30, while the solubility of component (A) in a developer containing an organic solvent remains unchanged in the unexposed portion 30B of the photosensitive film 30. This results in a difference in solubility in a developer containing an organic solvent between the exposed portion 30A and the unexposed portion 30B of the photosensitive film 30. In other words, the photosensitive film 30 is negative-tone. Therefore, when the photosensitive film 30 is developed with a developer containing an organic solvent, the unexposed portion 30B is dissolved and removed, forming a negative-tone pattern.

[0202] Here, the negative photosensitive film 30 of the photosensitive resist film 30F is typically made of a B-stage (semi-cured) resin material. The photosensitive resist film 30F may be a laminated film in which the photosensitive film 30 is laminated on a base film. The photosensitive resist film 30F according to this embodiment preferably uses a laminated film in which the photosensitive film 30 is laminated on a base film.

[0203] The photosensitive resist film 30F can be produced by applying the above-described negative photosensitive composition to a substrate film and drying it to form a photosensitive film 30. The negative photosensitive composition can be applied to the substrate film by an appropriate method using an applicator, blade coater, lip coater, comma coater, film coater, or the like. The thickness of the photosensitive film 30 is preferably 100 μm or less, and more preferably 5 to 50 μm.

[0204] The substrate film may be a known film, such as a thermoplastic resin film. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate. The thickness of the substrate film is preferably 2 to 150 μm.

[0205] [Step (i)] In step (i), the photosensitive resist film 30F is disposed so that the surface of the photosensitive film 30 constituting the photosensitive resist film 30F covers the opening of the recess 15. Thereafter, the base film is peeled off from the photosensitive film 30 constituting the photosensitive resist film 30F. In FIG. 1 , the photosensitive film 30 constituting the photosensitive resist film 30F is disposed so as to face the substrate 10 via the sidewall 20. Then, a hollow, sealed space (cavity) is formed surrounded by the substrate 10, the sidewall 20, and the photosensitive film 30.

[0206] [Step (ii)] In step (ii), the photosensitive film 30 is exposed to light. For example, the photosensitive film 30 is selectively exposed to light through a photomask 60 on which a predetermined pattern is formed, using a known exposure device.

[0207] The wavelength used for exposure is not particularly limited, and radiation such as ultraviolet light having a wavelength of 300 to 500 nm, ghi rays, i rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). The radiation source for these radiations may be a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like. The exposure dose is 100 to 1500 mJ / cm. ２ is preferred, and 200 to 900 mJ / cm ２ is more preferred.

[0208] [Step (iii)] In step (iii), the exposed photosensitive film 30 is subjected to a heat treatment, known as a post-exposure bake (PEB) treatment. The PEB treatment is carried out, for example, at a temperature of 80 to 150°C for 40 to 600 seconds, preferably 60 to 300 seconds. As a result of the heat treatment in step (iii), the exposed photosensitive film 30 becomes an exposed portion 30A in which the epoxy groups in component (A) have undergone ring-opening polymerization, and an unchanged unexposed portion 30B.

[0209] [Step (iv)] In step (iv), the photosensitive film 30 (exposed portion 30A, unexposed portion 30B) after the PEB treatment is developed to form a negative pattern (exposed portion 30A). The development here can be carried out in the same manner as in the above-mentioned [developing step]. After the development, a rinsing treatment is preferably carried out. By the development in step (iv), the unexposed portion 30B is dissolved and removed, and the exposed portion 30A remains as a negative pattern. The exposed portion 30A becomes the top plate portion (the roof that covers the opening surface of the recess).

[0210] [Step (v)] In step (v), the developed negative pattern (exposed portion 30A) is further hardened by heat treatment (curing operation) to obtain a hollow structure 100 in which the exposed portion 30A (top plate portion) is made of a hardened body 40 of the photosensitive film 30. The heat treatment is carried out, for example, at a temperature of 150 to 300°C for 10 minutes to 5 hours, preferably 1 to 3 hours. A nitrogen atmosphere is preferred as the atmosphere for the heat treatment. In FIG. 1 , the hardened body 40 is formed by hardening the photosensitive material forming the sidewall 20 and the photosensitive film 30, respectively, and integrating them.

[0211] (Pattern Forming Method) The pattern forming method of this embodiment includes a step of forming a photosensitive film on a support using the negative photosensitive composition of the above-mentioned embodiment (hereinafter referred to as a "film forming step"), a step of exposing the photosensitive film to light (hereinafter referred to as an "exposure step"), and a step of developing the exposed photosensitive film with a developer containing an organic solvent to form a negative pattern (hereinafter referred to as a "development step"). The pattern forming method of this embodiment can be performed, for example, as follows.

[0212] [Film Formation Step] First, the negative photosensitive composition of the above-described embodiment is applied onto a support by a known method such as spin coating, roll coating, screen printing, or doctor blade coating, and then baked (post-applied bake (PAB)) for 2 to 60 minutes at a temperature of, for example, 60 to 180° C. to form a photosensitive film. Note that the film formation step can also be performed by disposing the photosensitive composition layer of the above-described laminate film on the support.

[0213] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, silicon, silicon nitride, titanium, tantalum, lithium tantalate (LiTaO ３ ), niobium, lithium niobate (LiNbO ３ Examples of suitable materials include metal substrates such as palladium, titanium tungsten, copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0214] The pattern forming method of this embodiment is, for example, for forming a lithium tantalate (LiTaO ３ ) substrate, lithium niobate (LiNbO ３ ) is a useful method for substrates.

[0215] The thickness of the photosensitive film formed from the negative photosensitive composition is not particularly limited, but is preferably about 10 to 100 μm. The negative photosensitive composition of the above-described embodiment can provide good properties even when a thick film is formed.

[0216] [Exposure Step] Next, the formed photosensitive film is selectively exposed using a known exposure device, for example, through a mask (mask pattern) having a predetermined pattern formed thereon, or by direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) as needed, for example, at a temperature of 80 to 150°C for 40 to 1200 seconds, preferably 40 to 1000 seconds, and more preferably 60 to 900 seconds.

[0217] The wavelength used for exposure is not particularly limited, and radiation such as ultraviolet light having a wavelength of 300 to 500 nm, i-rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). Examples of radiation sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and argon gas lasers. Here, radiation refers to ultraviolet light, visible light, far ultraviolet light, X-rays, electron beams, and the like. The radiation dose varies depending on the type and amount of each component in the composition, the thickness of the coating film, and the like, but for example, when an ultra-high-pressure mercury lamp is used, it is 100 to 2000 mJ / cm. ２ is.

[0218] The exposure method for the photosensitive film may be a normal exposure (dry exposure) carried out in air or an inert gas such as nitrogen, or may be liquid immersion exposure (liquid immersion lithography).

[0219] The photosensitive film after the exposure step has high transparency, and for example, the haze value when irradiated with i-line (wavelength 365 nm) is preferably 3% or less, more preferably 1.0 to 2.5%. Thus, the photosensitive film formed using the negative photosensitive composition of the above-described embodiment has high transparency. Therefore, during exposure in pattern formation, light transmittance is increased, making it easier to obtain a negative pattern with good lithography properties. The haze value of the photosensitive film after such an exposure step is measured using a method in accordance with JIS K 7136 (2000).

[0220] [Development Step] Next, the photosensitive film after exposure is developed with a developer containing an organic solvent (organic developer). After development, a rinse treatment is preferably performed. If necessary, a bake treatment (post-bake) may be performed.

[0221] The organic solvent contained in the organic developer may be any solvent capable of dissolving the component (P0) (the component (P0) before exposure), and may be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0222] 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, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0223] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, 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 monoethyl ether acetate, diethylene glycol monophenyl 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, Pyrene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 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, milk Examples of the alkyl esters include ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.Among these, butyl acetate or PGMEA is preferred as the ester solvent.

[0224] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0225] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, but examples include ionic and nonionic fluorine-based and / or silicon-based surfactants. Nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is blended, the blending amount is typically 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, based on the total amount of the organic developer.

[0226] The development process can be carried out by a known development method, for example, a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method), etc.

[0227] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method. Examples of the rinse treatment method include a method in which the rinse solution is continuously applied onto a support rotating at a constant speed (spin coating method), a method in which the support is immersed in the rinse solution for a certain period of time (dip method), and a method in which the rinse solution is sprayed onto the surface of the support (spray method). For the rinse treatment, it is preferable to use a rinse solution containing an organic solvent.

[0228] A negative pattern can be formed by the above-described film forming step, exposure step, and development step.

[0229] (Cured Film) The cured film of this embodiment is obtained by curing the negative photosensitive composition of the above-described embodiment.

[0230] (Method for Producing Cured Film) The method for producing a cured film of this embodiment includes step (i) of forming a photosensitive film on a support using the negative photosensitive composition of the embodiment described above, and step (ii) of curing the photosensitive film to obtain a cured film. The operation of step (i) can be performed in the same manner as the above-described [Film Formation Step]. The baking treatment can be performed, for example, at a temperature of 60 to 150°C for 40 to 600 seconds. The curing treatment in step (ii) can be performed, for example, at a temperature of 100 to 250°C for 0.5 to 2 hours. The method for producing a cured film of this embodiment may include other steps in addition to steps (i) and (ii). For example, the above-described [Exposure Step] may be included between steps (i) and (ii). In this case, the photosensitive film formed in step (i) may be selectively exposed, and the photosensitive film (pre-cured film) that has been subjected to a post-exposure bake (PEB) treatment as needed may be cured to obtain a cured film. According to the method for producing a cured film of the embodiment described above, a cured film that faithfully reproduces a mask pattern can be easily produced.

[0231] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0232] <Preparation of Negative Photosensitive Compositions> (Examples 1 to 10, Comparative Examples 1 and 2) Each of the components shown in Table 1 was mixed and dissolved in methyl ethyl ketone (MEK), and the resulting solution was filtered using a PTFE filter (pore size 1 μm, manufactured by PALL Corporation) to prepare a negative photosensitive composition (solution with a solid content of 78% by mass) for each example.

[0233]

[0234] In Table 1, the abbreviations have the following meanings. The values ​​in brackets [ ] indicate the blending amount of each component (parts by mass; converted to solid content). (A)-1: A polyfunctional epoxy compound represented by the following chemical formula (A1-1).

[0235]

[0236] (A)-2: A polyfunctional epoxy compound represented by the following chemical formula (A1-2).

[0237]

[0238] (A)-3: A difunctional aromatic epoxy compound represented by the following chemical formula (A1-3).

[0239]

[0240] (A)-4: A difunctional alicyclic epoxy compound represented by the following chemical formula (A1-4).

[0241]

[0242] (I)-1: A sulfonium salt represented by the following chemical formula (I0-1).

[0243]

[0244] <Pattern Forming Method> A negative pattern (residual film) was formed on a silicon wafer by the following film forming step, exposure step, and development step, and the taper angle was evaluated.

[0245] Film formation process: The negative photosensitive composition of each example was applied to a substrate film using an applicator and baked (PAB) in an oven at 70°C for 10 minutes to form a photosensitive film with a thickness of 20 μm, thereby obtaining a laminated film. The photosensitive resist film was laminated onto a silicon wafer under conditions of 80°C, 0.3 MPa, and 0.5 m / min. The film was then baked (PAB) for 5 minutes on a hot plate at 120°C.

[0246] Exposure step: The base film was peeled off from the photosensitive film of the laminated film. Then, using an MA / BA 8 Gen4 Pro aligner manufactured by SUSS MicroTec, the photosensitive film was irradiated with 400 mJ / cm at a gap of 30 μm. ２ The exposed photosensitive film was then subjected to post-exposure heating on a hot plate at 110° C. for 5 minutes.

[0247] Development step: The photosensitive film after the heat treatment was developed for 120 seconds using propylene glycol monomethyl ether acetate as a developer to form a negative pattern (residual film). As a result, a 50 μm × 50 μm square pattern was formed.

[0248] [Taper Angle Evaluation] FIG. 2 is a diagram schematically showing a cross section of a substrate having a square pattern, which is made up of a silicon wafer 101 and a residual film 501 on the silicon wafer 101. The square pattern was observed with a scanning electron microscope (product name: SU-5000, manufactured by Hitachi High-Technologies Corporation), and the angle θ (taper angle) formed between the silicon wafer 101 and the peripheral portion of the residual film 501 in contact with the silicon wafer 101 was measured and evaluated according to the following criteria. The evaluation results are shown in Table 2. Criteria: A: θ was 87° or more. B: θ was 85° or more and less than 87°. C: θ was 80° or more and less than 85°. D: θ was less than 80°. Evaluations A to C were considered pass, and evaluation D was considered fail.

[0249] <Production of hollow structure> Using the negative photosensitive composition of each example, a substrate having a recess on its surface surrounded by a side wall was produced, and a photosensitive film formed using the negative photosensitive composition of each example was attached to the side wall so as to cover the opening of the recess, and the attachment property was evaluated.

[0250] Film formation process: The negative photosensitive composition of each example was applied to a substrate film using an applicator and baked (PAB) in an oven at 70°C for 10 minutes to form a photosensitive film with a thickness of 20 μm, thereby obtaining a laminated film. The photosensitive resist film was laminated onto a silicon wafer under conditions of 80°C, 0.3 MPa, and 0.5 m / min. Next, a baking (PAB) process was performed on a hot plate at 120°C for 5 minutes.

[0251] Exposure step: The base film was peeled off from the photosensitive film of the laminated film. Then, using an MA / BA 8 Gen4 Pro aligner manufactured by SUSS MicroTec, the photosensitive film was irradiated with 400 mJ / cm at a gap of 30 μm. ２The exposed photosensitive film was then subjected to post-exposure heating on a hot plate at 110° C. for 5 minutes.

[0252] Development step: Next, puddle development was performed using PGMEA as a developer at 23°C for 120 seconds, followed by shaking off and drying, followed by heating for 1 hour at 200°C in a nitrogen atmosphere to harden. As a result, a walled substrate was obtained, in which a recessed pattern was formed on the Si substrate, with the periphery of a 1170µm long x 1500µm wide square being surrounded by a 50µm wide sidewall made of the cured film.

[0253] Next, a 20 μm thick laminate film was produced using the negative photosensitive composition of each example using the same method as above. Next, using a TEAM-100ARF manufactured by Takatori Corporation, the photosensitive film of the laminate film was laminated and attached to the sidewall so as to cover the opening of the recess in the walled substrate. The sidewall (wall) and top plate portion (roof covering the opening of the recess) of the hollow structure were formed using the same negative photosensitive composition. The lamination conditions were a stage temperature of 30°C, a roller temperature of 40°C, a porous temperature of 23°C, a roller speed of 5.0 mm / s, a roller pressure of 300 kPa, and an atmospheric tension mode.

[0254] [Evaluation of Adhesion] One hundred structures, each having a top plate laminated to a side wall, produced using the negative photosensitive composition of each example were observed under a microscope, and the number of structures in which the top plate and side wall were not properly attached to each other was counted and evaluated according to the following criteria for adhesion of the top plate. The evaluation results are shown in Table 2. Criteria: A: The number of hollow structures with poor adhesion was 0. B: The number of hollow structures with poor adhesion was 1 to 3. C: The number of hollow structures with poor adhesion was 4 to 9. D: The number of hollow structures with poor adhesion was 10 or more. Evaluations A to C were considered pass, and evaluation D was considered fail.

[0255]

[0256] 10 Substrate, 15 Recess, 20 Side wall, 30 Photosensitive film, 30A Exposed portion (top plate portion), 30B Unexposed portion, 30F Photosensitive resist film, 40 Hardened body, 60 Photomask, 100 Hollow structure, 101 Silicon wafer, 501 Residual film

Claims

1. A negative-type photosensitive composition comprising a trifunctional or higher polyfunctional epoxy compound, a cationic polymerization initiator, and a bifunctional aromatic epoxy compound having a molecular weight of 800 or less, wherein the content of the bifunctional aromatic epoxy compound is 0.6 to 10 mass% relative to the total content (100 mass%) of the polyfunctional epoxy compound and the bifunctional aromatic epoxy compound.

2. The negative photosensitive composition according to claim 1, wherein the content of the difunctional aromatic epoxy compound is 0.7 to 8 mass% relative to the total content (100 mass%) of the polyfunctional epoxy compound and the difunctional aromatic epoxy compound.

3. The negative photosensitive composition according to claim 1, wherein the polyfunctional epoxy compound comprises a bisphenol novolac type epoxy resin.

4. The negative-type photosensitive composition according to claim 3, wherein the difunctional aromatic epoxy compound comprises a bisphenol epoxy monomer.

5. The negative photosensitive composition according to claim 1 or 2, which is used to form a top plate portion of a hollow structure comprising a recess and a top plate portion covering the opening of the recess.

6. A photosensitive resist film in which a photosensitive film formed using the negative photosensitive composition according to claim 1 or 2 and a cover film are laminated in this order on a base film.

7. A method for manufacturing a hollow structure comprising a recess and a top plate portion covering an opening of the recess, the top plate portion being formed using the negative photosensitive composition according to claim 1 or 2.

8. A pattern forming method comprising the steps of: forming a photosensitive film on a support using the negative photosensitive composition according to claim 1 or 2; exposing the photosensitive film; and developing the exposed photosensitive film with a developer containing an organic solvent to form a negative pattern.

9. A pattern forming method comprising the steps of: forming a photosensitive film on a support using the photosensitive resist film according to claim 5; exposing the photosensitive film; and developing the exposed photosensitive film with a developer containing an organic solvent to form a negative pattern.

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