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

Abstract

To provide: a negative photosensitive composition which enables formation of a pattern having a good shape and can improve stickability thereof to a side wall of a hollow structure; a photosensitive resist film having a photosensitive film using the same; a method for producing a hollow structure using the negative photosensitive composition; and a method for forming a pattern.SOLUTION: A negative photosensitive composition comprises: a tri- or more polyfunctional epoxy compound; a cationic polymerization initiator; and a bifunctional aromatic epoxy compound having a molecular weight of 800 or less. In the negative photosensitive composition, a content ratio of the bifunctional aromatic epoxy compound is 0.6 to 10 mass% relative to a total amount (100 mass%) of the polyfunctional epoxy compound and the bifunctional aromatic epoxy compound.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a negative photosensitive composition, a photosensitive resist film, a method for producing a hollow structural body, and a method for forming a pattern. [Background technology]

[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, especially for smartphones and other devices that handle high frequencies, there will be an increasing demand for miniaturization of packages with hollow encapsulation structures (hereinafter, referred to as hollow structures).

[0003] FIG. 3 is a schematic cross-sectional view showing an example of the structure of the hollow structure 100. As shown in FIG. The hollow structure 100 comprises 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 surface of a recess 15 formed by the sidewall 20 and the substrate 10. The hollow structural body 100 is manufactured, for example, as follows. First, a photosensitive film formed by applying a photosensitive composition onto a substrate 10 is selectively exposed to light to manufacture the side wall 20. Next, a photosensitive film is attached to the side wall 20 so as to cover the recess 15, and then selective exposure is performed to manufacture the top plate portion 30A.

[0004] When forming a sidewall of a hollow structure on a substrate, there is a problem that undercuts are likely to occur at the peripheral portion of the negative pattern in contact with 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 a specific structural unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2022-101132 Summary of the Invention [Problem to be solved by the invention]

[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 a side wall formed on a substrate.

[0007] Therefore, an object of the present invention is to provide a negative-type photosensitive composition that is capable of forming a pattern of a good shape and has improved adhesion to the side walls of a hollow structure, a photosensitive resist film having a photosensitive film formed using the composition, a method for manufacturing a hollow structure using the negative-type photosensitive composition, and a pattern forming method. [Means for solving the problem]

[0008] The present invention includes the following aspects. A first aspect of the present invention is a negative 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 producing a hollow structural body comprising a recess and a top plate portion covering an opening surface of the recess, the top plate portion being 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 to light, and developing the exposed photosensitive film with a developer containing an organic solvent to form a negative pattern. Effect of the Invention

[0012] According to the present invention, it is possible to provide a negative photosensitive composition that can form a pattern of a 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 forming method. [Brief description of the drawings]

[0013] [Figure 1] 1A to 1C are schematic diagrams illustrating a method for manufacturing a hollow structure according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram for explaining a taper angle formed between a residual photosensitive film and a silicon wafer in an embodiment. [Diagram 3] FIG. 2 is a schematic diagram showing a cross section of a hollow structure according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In this specification and the claims, the term "aliphatic" is a relative concept to aromaticity and is defined as meaning a group or compound that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in an alkoxy group. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The term "halogenated alkyl group" refers to an alkyl group in which some or all of the hydrogen atoms have been substituted with halogen atoms, and examples of the halogen atoms include fluorine, chlorine, bromine and iodine atoms. The term "fluorinated alkyl group" refers to an alkyl group in which some or all of the hydrogen atoms have been substituted with fluorine atoms. The phrase "optionally has a substituent" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is intended to include any concept including irradiation with radiation.

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

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

[0017] When a photosensitive film is formed using such a negative photosensitive composition and selectively exposed to light, the cationic part of the cationic polymerization initiator decomposes in the exposed part of the photosensitive film to generate acid, and the epoxy group in the (A) component undergoes ring-opening polymerization due to the action of the acid, reducing the solubility of the (A) component in a developer containing an organic solvent (organic developer), while the solubility of the (A) component in an organic developer does not change in the unexposed part of the photosensitive film, resulting in a difference in solubility in an organic developer between the exposed part and the unexposed part of the photosensitive film. Therefore, when the photosensitive film is developed with an organic developer, the unexposed part is dissolved and removed, forming a negative pattern.

[0018] <Trifunctional or higher multifunctional epoxy compounds (Ap)> As the component (Ap), a polyfunctional epoxy compound having three or more functional groups and having sufficient epoxy groups to form a negative pattern by exposure is used.

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

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

[0021] [ka] [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. n1 is an integer of 1 to 5. R EP is an epoxy group-containing group. EP may be the same or different.

[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 them, R p1 , R p2 As the alkyl group, a hydrogen atom or a linear or branched alkyl group is preferable, a hydrogen atom or a linear alkyl group is more preferable, and a hydrogen atom or a methyl group is particularly preferable. In formula (Ap-1), a plurality of R p1 may be the same or different. p2 may be the same or different from each other.

[0023] In formula (Ap-1), n1 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. R EP The 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 an alicyclic epoxy group and a divalent linking group. The alicyclic epoxy group is an alicyclic group having an oxacyclopropane structure which is a three-membered ring ether, and specifically, is a group having an alicyclic group and an oxacyclopropane structure. The alicyclic group that is the basic skeleton of the alicyclic epoxy group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include a norbornyl group, an isobornyl group, a tricyclononyl group, a tricyclodecyl group, and a tetracyclododecyl group. The hydrogen atom of these alicyclic groups may be substituted with an alkyl group, an alkoxy group, a hydroxyl group, 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 linked 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 optionally substituted divalent hydrocarbon group: Such a 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 straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0027] The linear aliphatic hydrocarbon group preferably has a carbon number of 1 to 10, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. 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 preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0028] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is present in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 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 are removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof 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, specific examples of which 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. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having (4n+2) π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[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, which may 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 the structure as the divalent hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or 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, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and 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, with a fluorine atom being preferred. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups 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 heteroatom. Preferred examples of the substituent containing a heteroatom include -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0032] In the aromatic hydrocarbon group as a divalent hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the 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 divalent linking groups containing heteroatoms: The heteroatom in the divalent linking group containing a heteroatom is an atom other than a carbon atom or a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

[0034] In the divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-; -C(=O)-NH-, -NH-, -NH-C(=O)-O-, -NH-C(=NH)- (H may be substituted by a substituent such as an alkyl group or an acyl group); -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 , -[Y 21 -C(=O)-O] m” -Y 22 -or-Y 21 -OC(=O)-Y 22 -, wherein Y 21 and Y 22 each independently represents 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, acyl, etc. 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 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -or-Y 21 -OC(=O)-Y 22 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same ones as the "divalent hydrocarbon group which may have a substituent" listed above in the description of the divalent linking group. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. Y 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. Formula − [Y 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, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by the formula -Y21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still 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, still more preferably 1 or 2, and most preferably 1.

[0035] Among them, R EP As the epoxy group-containing group in the formula (I), a glycidyl group is preferred.

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

[0037] [ka] [In formula (Ap-2), R p3 , R p4 and R p5 Rm each independently represents 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.

[0038] In the formula (Ap-2), R p3 , R p4 and R p5The 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 them, 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 above formula (Ap-2), Rm EP is an epoxy group-containing group, and R in the formula (Ap-1) EP and a glycidyl group is preferred. Multiple Rm EP may be the same or different from each other.

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

[0041] [ka]

[0042] As the trifunctional epoxy compound, one type may be used alone, or two or more types may be used in combination. As the trifunctional epoxy compound, among them, a compound having a structure in which the distance between three epoxy groups is large within the molecule is preferable since an intramolecular crosslinking reaction is unlikely to proceed, tris(4-hydroxyphenyl)methane triglycidyl ether or the trifunctional epoxy compound represented by the above general formula (Ap-2) is more preferable, the trifunctional epoxy compound represented by the above general formula (Ap-2) is particularly preferable, and the trifunctional epoxy compound represented by the above formula (Ap-2-1) is most preferable.

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

[0044] [ka] [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 above formula (anv1), R a22 , R a23 The alkyl group having 1 to 5 carbon atoms is represented by R p1 , R p2 The above alkyl group has 1 to 5 carbon atoms. R a22 , R a23 The halogen atom is preferably a chlorine atom or a bromine atom. In the above formula (anv1), R EP is R in the formula (Ap-1). EP and a glycidyl group is preferred.

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

[0047] [ka]

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

[0049] [ka] [In the formula, R a24 R is a hydrocarbon group which may have a substituent. a25 ~R a26 , R a28 ~R a30 R each independently represents 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 above 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 preferable, and a methyl group or an ethyl group is more preferable.

[0051] The branched alkyl group preferably has a carbon number of 3 to 10, and 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, and is preferably an isopropyl group.

[0052] R a24 When 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. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0053] R a24 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system 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, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. R a24 Specific examples of the aromatic hydrocarbon group in include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or 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., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0054] In the above formulas (anv2) and (anv3), R a25 ~R a26 , R a28 ~Ra30 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 defined as R a22 , R a23 is the same as:

[0055] In the above 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 represented by R EP Same as R a27 The optionally substituted hydrocarbon group is R a24 is the same as:

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

[0057] [ka]

[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 in 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, 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, EPICLON HP5000 (all manufactured by DIC Corporation), and EOCN-1020 (manufactured by Nippon Kayaku Co., Ltd.).

[0060] When the above-mentioned commercially available products contain 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 impurities is not particularly limited, and any known method can be used. Examples of the method for removing impurities include washing a commercially available product with a solvent in which only impurities dissolve, reprecipitation of the (Ap) component, fractionation by preparative GPC, fractionation using a dialysis membrane, etc.

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

[0062] The epoxy equivalent of the 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 the 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) with molecular weight of 800 or less> For 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] [ka] [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 * R may form an optionally substituted alicyclic group together with EP is an epoxy group-containing group. EP may be the same or different.

[0068] In the above formula (Am-1), R p6 , R p7 The alkyl group having 1 to 5 carbon atoms is represented by R p1 , R p2 The above alkyl group has 1 to 5 carbon atoms. R p6 and R p7 and are mutually bonded to form C * When an optionally substituted alicyclic group is formed together with the above, the alicyclic group preferably contains 3 to 11 carbon atoms, more preferably 3 to 8 carbon atoms, and even more preferably 3 to 6 carbon atoms. In the above formula (Am-1), R EP is 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 mass % or more, more preferably 80 to 99 mass %, and even more preferably 85 to 95 mass %, relative to the total mass (100 mass %) of the solid contents of the negative photosensitive composition.

[0070] In the negative photosensitive composition according to this embodiment, the content of the component (Am) is 0.6 to 10 mass%, preferably 0.7 to 8.0 mass%, and more preferably 0.8 to 2.0 mass%, relative to the total mass (100 mass%) of the components (Ap) and (Am). When the content of the (Am) component is equal to or greater than the lower limit of the above-mentioned preferred range, the adhesion of the photosensitive film for forming the top plate portion to the side wall of the hollow structure is improved when the hollow structure is formed, whereas when the content is equal to or less than the upper limit of the above-mentioned preferred range, a pattern having a good shape with high rectangularity is easily formed when the pattern is formed.

[0071] In the negative photosensitive composition according to this embodiment, the content of the component (Ap) is 90 to 99.4 mass%, preferably 92 to 99.3 mass%, and more preferably 98 to 99.2 mass%, relative to the combined mass (100 mass%) of the components (Ap) and (Am). When the content of component (Ap) is equal to or greater than the lower limit of the preferred range, a pattern having a good shape with high rectangularity is easily formed during pattern formation, whereas when the content is equal to or less than the upper limit of the preferred range, the adhesion of a photosensitive film for forming a top plate portion to the side wall of a hollow structure is easily improved during formation 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. Other epoxy group-containing compounds include, for example, bisphenol type epoxy resins (bisphenol A type epoxy resins, bisphenol F type epoxy resins), acrylic resins, aliphatic epoxy resins, and the like.

[0073] An example of the bisphenol type epoxy resin is an epoxy resin represented by the following general formula (abp1).

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

[0075] In formula (abp1), R a31 , R a32 The alkyl group having 1 to 5 carbon atoms is represented by R p1 , R p2 The alkyl group having 1 to 5 carbon atoms is the same as that of R a31 , R a32 is preferably a hydrogen atom or a methyl group. R EP is 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] [ka] [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 is a divalent hydrocarbon group which may have a substituent. 41 is an integer between 0 and 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 between 1 and 2.

[0078] In the above formula (a1-1), 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. 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 for 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, and a fluorine atom is 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 viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferable.

[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 explained in the above. Among the above, Va 41 The hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably a linear or branched aliphatic hydrocarbon group, further 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, and preferably 0 or 1.

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

[0082] In formula (a1-2), Wa 41 In (na 43 The aliphatic hydrocarbon group having a valence of +1 means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group in which a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure are combined.

[0083] Furthermore, the acrylic resin in the component (A) may have a structural unit derived from another polymerizable compound for the purpose of appropriately controlling the physical and chemical properties. Examples of such polymerizable compounds include known radically polymerizable compounds and anionically polymerizable compounds. Examples of such polymerizable compounds include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a 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; meth ... Examples of suitable polymerizable compounds include (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 will also be referred to as "component (m01)").

[0085] [ka] [In the formula, REP is an epoxy group-containing group. EP may be the same or different.

[0086] In the formula (m-01), R EP is an epoxy group-containing group, and R in the formula (Ap-1) EP is the same as:

[0087] Commercially available products that can be used as the (m01) component include, for example, 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] As the component (m01), 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 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] As another example of the epoxy group-containing compound, a compound having a structure represented by the following general formula (m-02) (hereinafter, this compound is also referred to as "(m02) component") may be preferably mentioned. The (m02) component may form a condensed ring.

[0090] [ka] [In the formula, n2 is an integer of 1 to 4.]

[0091] In the above formula (m-02), n2 is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2.

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

[0093] Examples of the (m02) component include compounds represented by the following chemical formula: In the following 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] [ka]

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

[0096] As the component (m02), 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 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 type 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, and the like, 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 the component (I1) (other cationic polymerization initiators).

[0099] Onium borate salts Onium borate salts (component (I1)) generate a relatively strong acid upon exposure to light. Therefore, by forming a pattern using a negative photosensitive composition containing component (I1), sufficient sensitivity is obtained and a good pattern is formed. In addition, the use of component (I1) is less likely to cause toxicity or metal corrosion. Suitable examples of the component (I1) include compounds represented by the following general formula (I1).

[0100] [ka] [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 section In the formula (I1), R b01 ~R b04 The aryl group in the formula (I) preferably has 5 to 30 carbon atoms, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples include a naphthyl group, a phenyl group, and an anthracenyl group, and the phenyl group is preferred because of its easy availability. R b01 ~R b04 The aryl group in 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 them, R in formula (I1) b01 ~R b04 As each of these, a fluorinated phenyl group is preferable, and a perfluorophenyl group is particularly preferable.

[0102] A preferred example of the anion portion of the compound represented by formula (I1) is tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - );Tetrakis[(trifluoromethyl)phenyl]borate ([B(C6H4CF3)4] - );Difluorobis(pentafluorophenyl)borate ([(C6F5)2BF2] - );Trifluoro(pentafluorophenyl)borate ([(C6F5)BF3] - );Tetrakis(difluorophenyl)borate ([B(C6H3F2)4] - ) etc. Among them, tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - ) is particularly preferred.

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

[0104] [ka] [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. 210is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- 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. W 201 represents a (x+1)-valent linking group.

[0105] R 201 ~R 207 , and R 211 ~R 212 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 , and R 211 ~R 212 The heteroaryl group in the above formula (I) may be one in which a part of the carbon atoms constituting the aryl group is replaced with a heteroatom. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroaryl group include a group in which one hydrogen atom has been removed from 9H-thioxanthene; 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 is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 , and R 211 ~R 212 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212Examples 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 (ca-r-1) to (ca-r-10).

[0106] [ka] [In the formula, R' 201 each independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0107] In the above formulas (ca-r-1) to (ca-r-10), R' 201 each independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0108] Optionally substituted cyclic groups: 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 the formula (I) 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, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group in the above 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, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, etc. R' 201 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, anthracenyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), 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, etc.), and a group in which one hydrogen atom has been removed from an aromatic heterocycle (for example, 9H-thioxanthene, 9H-thioxanthen-9-one, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0110] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in 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 straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 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 obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed 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 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 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0113] Optionally substituted chain alkyl groups: 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. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group, and a docosyl group. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. 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] An optionally substituted chain alkenyl group: 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, further preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups 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 In the above formula, examples 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 do not include a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R Nis 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, in which a ring containing a sulfur atom in the ring skeleton in the formula is a 3- to 10-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 above 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 above formula (ca-3), R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms.

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

[0121] In the above formulas (ca-4) and (ca-5), x is 1 or 2. W 201 is a (x+1)-valent linking group, that is, a divalent or trivalent linking group. W 201 The divalent linking group in the formula (Ap-1) is preferably a divalent hydrocarbon group which may have a substituent. EP The divalent hydrocarbon groups which may have a substituent are preferably the same as those exemplified by W. 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 an arylene group alone is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and the phenylene group is particularly preferred. W 201 The trivalent linking group in 201 and a group in which one hydrogen atom has been removed from the divalent linking group represented by the formula: W 201 As the trivalent linking group in the formula (I), a group in which two carbonyl groups are bonded to an arylene group is preferable.

[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] [ka]

[0124] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent. The substituent may be any of 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 the

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

[0126] [ka]

[0127] [ka] [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), the cations represented by the following chemical formulas (ca-1-36) to (ca-1-48) are also preferable.

[0129] [ka]

[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 preferable.

[0131] [ka]

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

[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] [ka]

[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] [ka]

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

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

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

[0140] <Other cationic polymerization initiators> Examples of cationic polymerization initiators other than the above-mentioned 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 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 to light, so that when a negative-type photosensitive composition containing the component (I) is used to form a pattern, sufficient sensitivity can be obtained and a good pattern can be formed.

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

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

[0144] Anion section In the above formula (I2-1), R b05 is a fluorine atom or a fluorine-containing alkyl group which may have a substituent. b05 may be the same or different from each other. R b05The fluorinated alkyl group in the above formula preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and even more preferably 1 to 5. 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. Among them, R b05 is preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and further preferably a fluorine atom, a trifluoromethyl group or a pentafluoroethyl group.

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

[0146] [ka] [In the formula, R bf05 is 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 The substituents are the same as the optionally substituted fluorinated alkyl groups listed under 1. In formula (b0-2a), nb 1 is preferably an integer of 1 to 4, more preferably an integer of 2 to 4, and most preferably 3.

[0148] In the above formula (I2-2), R b06 is a fluorine atom or a fluorine-containing alkyl group which may have a substituent. b06 may be the same or different from each other. R b06 The fluorinated alkyl group in the above formula preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and even more preferably 1 to 5. 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. Among them, R b06 As the alkyl group, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms is more preferable, and a fluorine atom is even more preferable.

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

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

[0151] [ka] [In the formula, R b11 ~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. m is an integer of 1 or more, and M m+ are each independently an m-valent organic cation.

[0152] {Component (I3-1)} Anion section 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 R' 201Among the cyclic groups, chain alkyl groups, and chain alkenyl groups in the explanation of the above, those having no substituent or those having a substituent other than a halogen atom are exemplified. R 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. The aliphatic cyclic group is preferably a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like (which may have a substituent other than a halogen atom); R b12 The hydrocarbon group may have a substituent other than a halogen atom, and examples of the substituent include R b11 Examples of the substituents include those similar to the substituents other than halogen atoms that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above formula. The phrase "may have a substituent other than a halogen atom" as used herein not only excludes the case where a substituent consists of only halogen atoms, but also excludes the case where a substituent contains at least one halogen atom (for example, the case where the substituent is a fluorinated alkyl group, etc.).

[0153] Preferred specific examples of the anion portion of the component (I3-1) are shown below.

[0154] [ka]

[0155] ·Cation part In formula (I3-1), M m+ is an m-valent organic cation. M m+Suitable examples of the organic cation include the cations represented by the above general formulas (ca-1) to (ca-5), and among these, the cation represented by the above general formula (ca-1) is more preferred. 201 , R 202 , R 203 A sulfonium cation in which at least one of the above 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 because it improves the resolution and roughness characteristics. The substituents that the organic group may have are the same as those described above, and 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 (ca-r-1) to (ca-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. 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). Among these, the cation represented by the above formula (ca-1-29) is particularly preferred.

[0156] {Component (I3-2)} Anion section 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 R' 201 Among the cyclic groups, chain alkyl groups, and chain alkenyl groups in the explanation of the above, those having no substituent or those having a substituent other than a halogen atom are exemplified.

[0157] Among these, R b11 As the substituent, 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 are preferable. The substituent which these groups may have includes 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 connected via an alkylene group. 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 b11 The bond to V' in the following general formulas (y-al-1) to (y-al-7) is 101 It is.

[0158] [ka] [In the formula, V' 101 V' 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 may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 A part of the methylene groups in the alkylene group in the formula (I) 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 in which one hydrogen atom has been further removed from a cyclic aliphatic hydrocarbon group (a monocyclic alicyclic hydrocarbon group, a polycyclic alicyclic hydrocarbon group) such as those mentioned above 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. Specific examples of the chain alkyl group include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched alkyl groups such as 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.

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

[0163] [ka]

[0164] ·Cation part 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] In addition, the component (I) is preferably a cationic polymerization initiator that generates an acid having a pKa (acid dissociation constant) of -5 or less upon exposure, from the viewpoints of increasing the elasticity of the photosensitive film and facilitating the formation of a fine structure without leaving any residue. By using a cationic polymerization initiator that generates an acid having a pKa of -6 or less, more preferably a pKa of -8 or less, it is possible to obtain high sensitivity to exposure. The lower limit of the pKa of the acid generated by the component (I) is preferably -15 or more. By using a cationic polymerization initiator that generates an acid having such a suitable pKa, it is easy to achieve high sensitivity. Here, "pKa (acid dissociation constant)" refers to a commonly used index indicating the acid strength of a target substance. In this specification, pKa is a value at a temperature condition of 25°C. The pKa value can be determined by measurement using a known method. Alternatively, a calculated value using known software such as "ACD / Labs" (product name, manufactured by Advanced Chemistry Development) can 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 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 photosensitive composition used in this embodiment, the content of the 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, relative to 100 parts by mass of the total parts by mass of the components (Ap) and (Am). When the content of component (I) is equal to or greater than the lower limit of the preferred range, sufficient sensitivity is obtained, and the lithography characteristics 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 equal to or less than the upper limit of the preferred range, the sensitivity is appropriately controlled, and a pattern with a good shape is easily obtained.

[0168] <Other ingredients> The negative photosensitive composition of this embodiment may contain other components, if necessary, in addition to the above-mentioned components (Ap), (Am) and (I). The negative type photosensitive composition of the embodiment may contain, as desired, a compatible additive, for example, an epoxy group-containing compound other than the component (Ap) and the component (Am), a silane coupling agent, a sensitizer component, a metal oxide (M), a solvent, an additional resin for improving the performance of the film, a dissolution inhibitor, a basic compound, a plasticizer, a stabilizer, a colorant, an antihalation agent, and the like.

[0169] The silane coupling agent can be used as an adhesion promoter that improves adhesion to a substrate. Examples of the silane coupling agent include silane coupling agents having reactive substituents such as a carboxy group, a methacryloyl group, an isocyanate group, an epoxy group, etc. Specific examples include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. The silane coupling agents may be used alone or in combination of two or more kinds. When a silane coupling agent is included, the content thereof 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 the 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, and in addition, the adhesion between the cured film and the substrate is further increased.

[0170] The sensitizer component is not particularly limited as long as it can absorb energy due to exposure and transmit the 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; acetophene-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. The sensitizer component may be used alone or in combination of two or more kinds. When a sensitizer component is contained, the content thereof is preferably from 0.1 to 10 parts by mass, more preferably from 0.3 to 5 parts by mass, and even more preferably from 0.5 to 3 parts by mass, per 100 parts by mass of the component (P0). When the content of the sensitizer component is within the above preferred range, the sensitivity and resolution can be further improved.

[0171] The negative photosensitive composition of the present embodiment may further contain a metal oxide (M) (hereinafter also referred to as "component (M)") because it is easy to obtain a cured film with increased strength. Furthermore, by including component (M), a pattern with a good shape and high resolution can be formed. Examples of the component (M) include oxides of metals such as silicon (metallic silicon), titanium, zirconium, hafnium, etc. Among these, oxides of silicon are preferred, and among these, it is particularly preferred to use silica. In addition, the component (M) is preferably in the form of particles. Such particulate (M) component is preferably a particle group having a volume average particle diameter of 5 to 40 nm, more preferably a particle group having a volume average particle diameter of 5 to 30 nm, and even more preferably a particle group having a volume average particle diameter of 10 to 20 nm. When the volume average particle size of the (M) component is equal to or greater than the lower limit of the preferred range, the strength of the cured film is easily increased. On the other hand, when the volume average particle size is equal to or less than the upper limit of the preferred range, residues are less likely to be generated during pattern formation, and a pattern with higher resolution is easily formed. In addition, the transparency of the photosensitive film is improved. The particle size of the (M) component may be appropriately selected depending on the exposure light source. In general, it is considered that the effect of light scattering is hardly considered for particles having a particle size of 1 / 10 or less of the wavelength of light. For this reason, for example, when forming a fine structure by photolithography using i-line (365 nm), it is preferable to use a particle group (particularly preferably a silica particle group) having a primary particle size (volume average value) of 10 to 20 nm as the (M) component. As the component (M), one type may be used alone, or two or more types may be used in combination. When the component (M) is contained, its content is preferably from 5 to 50 parts by mass, and more preferably from 10 to 40 parts by mass, per 100 parts by mass of the component (P0). When the content of the (M) component is at least the lower limit of the above-mentioned preferred range, the strength of the cured film is further increased, whereas when the content is at most the upper limit of the above-mentioned preferred range, the transparency of the photosensitive film is further increased.

[0172] The negative photosensitive composition of this embodiment may further contain a solvent (hereinafter sometimes referred to as "component (S)"). Examples of the (S) component 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 such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether of the above polyhydric alcohols or the above compounds having an ester bond; 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) are preferred among these; cyclic ethers such as dioxane; 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 kinds.

[0173] The amount of component (S), when included, is not particularly limited and is appropriately set according to 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 (S) component can be used so that the solids concentration is 70% by mass or more, and the (S) component can be used so that the solids concentration is 60% by mass or more. Also, an embodiment that does not substantially contain the component (S) (that is, an embodiment in which the solids concentration is 100% by mass) can be adopted.

[0174] The negative 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% with respect to the total content (100 mass%) of the (Ap) and (Am) components. The negative type photosensitive composition according to this embodiment contains a predetermined amount of the (Ap) component, so that the solubility is easily reduced by exposure. In addition, the negative type photosensitive composition contains a predetermined amount of the (Am) component, so that the flowability is easily increased. Due to these synergistic effects, the negative type photosensitive composition according to this embodiment can form a pattern with a good shape and can improve the attachment property to the side wall of the hollow structure.

[0175] (Photosensitive resist film) The photosensitive resist film according to this embodiment is formed 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 onto a base film, drying the composition to form a photosensitive film, and then laminating a cover film onto the photosensitive film. The photosensitive composition may be applied onto the substrate film by a suitable 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 one, for example, 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] The cover film may be a known one, such as a polyethylene film, a polypropylene film, etc. The cover film is preferably a film having a smaller adhesive strength with the photosensitive film than the base film. The thickness of the cover film is preferably 2 to 150 μm, more preferably 2 to 100 μm, and further preferably 5 to 50 μm. The base film and the cover film may be made of the same film material, or different film materials.

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

[0180] [First step (S1)] In the first step, a side wall 20 is formed on a substrate 10 to obtain a substrate 10 having a recess 15 on its surface. In the [first step] of FIG. 1, a substrate 10 having a recess 15 on its surface is shown, which is formed by a substrate 10 and a side wall 20 formed on the substrate 10. As shown in FIG.

[0181] <Substrates with concave portions on the surface> Examples of the substrate 10 having the recesses 15 on its surface include a structure in which a pattern is formed on the substrate 10, a stepped substrate, etc. The recesses 15 may be made of either an organic material or an inorganic material. Such a substrate 10 having recesses 15 on its surface can be manufactured by a method including, for example, a step of forming a photosensitive film on a support using a negative photosensitive composition (hereinafter referred to as a "film forming step"), a step of exposing the photosensitive film (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 that becomes the sidewalls 20 of the recesses 15 (hereinafter referred to as a "development step"). The method of manufacturing such a substrate 10 having recesses 15 on its surface can be carried out as follows.

[0182] Film formation process: 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. The film-forming step can also be carried out by disposing a photosensitive composition layer, which has been previously prepared using a negative photosensitive composition, on a support.

[0183] The support is not particularly limited, and any conventionally known support can be used. For example, a substrate for electronic components, a substrate having a predetermined wiring pattern formed thereon, and the like can be mentioned. More specifically, examples of substrates for electronic components include metal substrates such as silicon, silicon nitride, titanium, tantalum, lithium tantalate (LiTaO3), niobium, lithium niobate (LiNbO3), palladium, titanium tungsten, copper, chromium, iron, and aluminum, as well as glass substrates. The wiring pattern may be made of a material such as copper, aluminum, nickel, or 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 process: Next, the formed photosensitive film is selectively exposed using a known exposure device, for example, by exposure through a mask (mask pattern) having a predetermined pattern formed thereon, or by drawing by direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) as necessary, for example, at a temperature condition 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 rays having a wavelength of 300 to 500 nm, i-rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). As the radiation source, a low pressure mercury lamp, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, an argon gas laser, etc. can be used. Here, radiation means ultraviolet light, visible light, far ultraviolet light, X-rays, electron beams, etc. The radiation dose varies depending on the type and amount of each component in the composition, the thickness of the coating film, etc. For example, when an ultra-high pressure mercury lamp is used, it is 100 to 2000 mJ / cm. 2 It is.

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

[0188] Development process: Next, the photosensitive film after the exposure is developed with a developer containing an organic solvent (organic developer). After the 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, specifically, 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-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethoxyethyl acetate, 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 lactate 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, the ester solvent is preferably butyl acetate or PGMEA.

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

[0193] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants. The surfactant is preferably a non-ionic surfactant, and more preferably a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant. When a surfactant is added, the amount added is usually from 0.001 to 5 mass %, preferably from 0.005 to 2 mass %, and more preferably from 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0194] The development process can be carried out by a known development method, such as 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 still for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and 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).

[0195] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously applying the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), or a method of spraying the rinse liquid onto the surface of the support (spray method). The rinsing treatment is preferably carried out using a rinsing liquid containing an organic solvent.

[0196] By the above-mentioned film forming step, exposure step, and development step, a substrate 10 having recesses 15 on its surface (a structure in which a pattern is formed on a substrate, a stepped substrate) can be manufactured. The thickness (horizontal dimension relative to the support) and height (vertical dimension relative to the support) of the side wall 20 can be set appropriately based on the size of the hollow portion, which is determined according to the type of electronic device to be accommodated in the recess 15.

[0197] [Second process (S2)] In the second step in this embodiment, an exposed portion 30A that serves as a top plate portion is formed on the side wall 20 formed in the first step, thereby producing the hollow structural body. The second step in this embodiment includes the following steps (i), (ii), (iii), (iv), and (v).

[0198] Step (i): A step of disposing the photosensitive resist film 30F so that the photosensitive resist film 30F covers the opening surface of the recess 15 formed by the side wall 20 and the substrate 10, and peeling off the base film from the photosensitive film 30 constituting the photosensitive resist film 30F. Step (ii): After step (i), a step of exposing the photosensitive film 30 to light. Step (iii): A step of subjecting the photosensitive film 30 after step (ii) to a heat treatment. Step (iv): After the step (iii), the photosensitive film 30 is developed to form a negative pattern (exposed portion 30A) that closes the opening of the recess 15 formed by the side wall 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 hardening the negative pattern (exposed portion 30A) after step (iv) by further 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] <About photosensitive resist film> The photosensitive resist film 30F in this embodiment has, for example, a negative photosensitive film 30 formed from the above-mentioned negative photosensitive composition.

[0201] When a photosensitive film 30 is formed using such a photosensitive resist film 30F and the photosensitive film 30 is selectively exposed to light, in the exposed portion 30A of the photosensitive film 30, the cationic portion of the (I) component decomposes to generate an acid, and the epoxy group in the (A) component undergoes ring-opening polymerization due to the action of the acid. As a result, the solubility of the component (A) in the developer containing an organic solvent decreases in the exposed portion 30A of the photosensitive film 30, while the solubility of the component (A) in the developer containing an organic solvent does not change in the unexposed portion 30B of the photosensitive film 30. Therefore, a difference in solubility in the developer containing an organic solvent occurs between the exposed portion 30A and the unexposed portion 30B of the photosensitive film 30. In other words, the photosensitive film 30 is negative type. 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 type 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 the present embodiment is preferably a laminated film in which the photosensitive film 30 is laminated on a base film.

[0203] Such a photosensitive resist film 30F can be produced by applying the above-mentioned negative photosensitive composition onto a base film and drying it to form a photosensitive film 30. The negative photosensitive composition may be applied onto the substrate film by a suitable method using an applicator, a blade coater, a lip coater, a comma coater, a 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 one, for example, 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] [[Process (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 surface of the recess 15. Thereafter, the base film is peeled off from the photosensitive film 30 constituting the photosensitive resist film 30F. 1, a photosensitive film 30 constituting a photosensitive resist film 30F is disposed so as to face a substrate 10 via a sidewall 20. 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 using a known exposure device through a photomask 60 on which a predetermined pattern is formed.

[0207] The wavelength used for exposure is not particularly limited, and radiation such as ultraviolet rays having a wavelength of 300 to 500 nm, ghi rays, i rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). As the source of these radiations, low pressure mercury lamps, high pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, argon gas lasers, etc. can be used. The dose of exposure is 100 to 1500 mJ / cm. 2 is preferable, 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, a so-called 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. By the heat treatment in step (iii), the photosensitive film 30 after exposure becomes an exposed portion 30A where the epoxy groups in the component (A) have undergone ring-opening polymerization, and an unexposed portion 30B where no change occurs.

[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 [Development 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 a top plate portion (a roof that covers the opening surface of the recess).

[0210] [[Process (v)]] In step (v), the negative pattern (exposed area 30A) after development is further hardened by heat treatment (curing operation) to obtain a hollow structural body 100 in which the exposed area 30A (top plate area) 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. The heat treatment is preferably carried out in a nitrogen atmosphere. In FIG. 1, the cured body 40 is formed by curing the photosensitive material forming the side wall 20 and the photosensitive film 30 and integrating them into one body.

[0211] (Pattern formation method) The pattern formation method of the present embodiment includes a step of forming a photosensitive film on a support using the negative photosensitive composition of the above-described embodiment (hereinafter referred to as a "film formation step"), a step of exposing the photosensitive film (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 carried out, for example, as follows.

[0212] [Film formation process] 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. The film-forming step can also be carried out by disposing the photosensitive composition layer on a support of the aforementioned laminated film.

[0213] The support is not particularly limited, and conventionally known ones can be used, such as a substrate for electronic components, a substrate on which a predetermined wiring pattern is formed, etc. More specifically, metal substrates such as silicon, silicon nitride, titanium, tantalum, lithium tantalate (LiTaO3), niobium, lithium niobate (LiNbO3), palladium, titanium tungsten, copper, chromium, iron, and aluminum, and glass substrates can be used. Materials for the wiring pattern include, for example, copper, aluminum, nickel, and gold.

[0214] The pattern formation method of the present embodiment is useful for, for example, lithium tantalate (LiTaO3) substrates and lithium niobate (LiNbO3) substrates for SAW devices mounted on communication terminals.

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

[0216] [Exposure process] Next, the formed photosensitive film is selectively exposed using a known exposure device by exposure through a mask having a predetermined pattern (mask pattern) or by drawing by direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) as necessary at a temperature of, for example, 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 rays having a wavelength of 300 to 500 nm, i-rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). As the radiation source, a low pressure mercury lamp, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, an argon gas laser, etc. can be used. Here, radiation means ultraviolet light, visible light, far ultraviolet light, X-rays, electron beams, etc. The radiation dose varies depending on the type and amount of each component in the composition, the thickness of the coating film, etc. For example, when an ultra-high pressure mercury lamp is used, it is 100 to 2000 mJ / cm. 2 It is.

[0218] The exposure method for the photosensitive film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be 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%. As described above, the photosensitive film formed using the negative photosensitive composition of the embodiment described above has high transparency, which increases the light transmittance during exposure in pattern formation, 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 process] Next, the photosensitive film after the exposure is developed with a developer containing an organic solvent (organic developer). After the 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 (P0) component (the (P0) component before exposure), and may be appropriately selected from known organic solvents. Specific examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and 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-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethoxyethyl acetate, 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 lactate 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, the ester solvent is preferably butyl acetate or PGMEA.

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

[0225] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants. The surfactant is preferably a non-ionic surfactant, and more preferably a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant. When a surfactant is added, the amount added is usually from 0.001 to 5 mass %, preferably from 0.005 to 2 mass %, and more preferably from 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0226] The development process can be carried out by a known development method, such as 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 still for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and 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).

[0227] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously applying the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), or a method of spraying the rinse liquid onto the surface of the support (spray method). The rinsing treatment is preferably carried out using a rinsing liquid containing an organic solvent.

[0228] A negative pattern can be formed by the above-mentioned 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 of manufacturing the cured film) The method for producing a cured film of the present embodiment includes a step (i) of forming a photosensitive film on a support using the negative-type photosensitive composition of the above-described embodiment, and a 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 in the above-mentioned [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 carried out under conditions of, for example, a temperature of 100 to 250° C. and a time of 0.5 to 2 hours. The method for producing a cured film according to the embodiment may have other steps in addition to steps (i) and (ii). For example, the above-mentioned [exposure step] may be included between steps (i) and (ii), and the photosensitive film formed in step (i) may be selectively exposed to light, and the photosensitive film (pre-cured film) that has been subjected to a bake (PEB) treatment as necessary 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. EXAMPLES

[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-type photosensitive composition> (Examples 1 to 10, Comparative Examples 1 to 2) The components shown in Table 1 were mixed and dissolved in methyl ethyl ketone (MEK), and filtered using a PTFE filter (pore size 1 μm, manufactured by PALL Corporation) to prepare negative-type photosensitive compositions (solutions with a solid content of 78% by mass) for each example.

[0233] [Table 1]

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

[0235] [ka]

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

[0237] [ka]

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

[0239] [ka]

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

[0241] [ka]

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

[0243] [ka]

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

[0245] Film formation process: The negative photosensitive composition of each example was applied onto 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 on a silicon wafer under the conditions of 80°C, 0.3 MPa, and 0.5 m / min. The coating was baked (PAB) on a hot plate at 120° C. for 5 minutes.

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

[0247] Development process: 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 square pattern of 50 μm × 50 μm was formed.

[0248] [Taper angle evaluation] 2 is a schematic diagram showing a cross section of a substrate having a square pattern, the substrate being made of a silicon wafer 101 and a residual film 501 of 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) 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. Judgment criteria: A: θ was 87° or greater. B: θ was greater than or equal to 85° and less than 87°. C: θ was greater than or equal to 80° and less than 85°. D: θ was less than 80°. Evaluations A to C were considered to be acceptable, and evaluation D was considered to be unacceptable.

[0249] <Manufacturing of hollow structures> Using the negative photosensitive composition of each example, a substrate having a recess on its surface surrounded by a sidewall was prepared, and a photosensitive film formed using the negative photosensitive composition of each example was attached to the sidewall 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 onto 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 on a silicon wafer under the conditions of 80°C, 0.3 MPa, and 0.5 m / min. Then, baking (PAB) was performed on a hot plate at 120° C. for 5 minutes.

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

[0252] Development process: Next, paddle development was carried out at 23° C. for 120 seconds using PGMEA as a developer, and after shaking off and drying, the film was heated at 200° C. for 1 hour in a nitrogen atmosphere to be cured. As a result, a recess pattern was formed on the Si substrate, in which a rectangular periphery of 1170 μm in length and 1500 μm in width was surrounded by a 50 μm-wide wall made of a cured film, thereby obtaining a substrate with walls.

[0253] Next, a laminate film having a thickness of 20 μm was prepared using each of the negative photosensitive compositions in the same manner as above. Next, the photosensitive film of the laminated film was laminated and attached to the side walls so as to close the opening of the recess in the walled substrate using TEAM-100ARF manufactured by Takatori Co., Ltd. The side walls (Wall) and top plate part (Roof (Roof) closing the opening of the recess) of the hollow structure were formed using the same negative type photosensitive composition. The lamination conditions were stage temperature 30°C, roller temperature 40°C, porous temperature 23°C, roller speed 5.0mm / s, roller pressure 300kPa, and air tension mode.

[0254] [Evaluation of application] 100 structures with the side walls laminated to the top plate, produced using the negative photosensitive composition of each example, were observed under a microscope, and the number of structures with poor adhesion between the top plate and the side walls was counted and evaluated according to the following criteria for the adhesion of the top plate. The evaluation results are shown in Table 2. Judgment criteria: A: The number of hollow structures with poor attachment was 0. B: The number of hollow structures with poor attachment was 1 to 3. C: The number of hollow structures with poor attachment was 4 to 9. D: The number of hollow structures with poor attachment was 10 or more. Evaluations A to C were considered to be acceptable, and evaluation D was considered to be unacceptable.

[0255] [Table 2]

[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 remaining film

Claims

1. The epoxy resin composition comprises 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, A negative photosensitive composition, wherein the content ratio of the difunctional aromatic epoxy compound is 0.6 to 10 mass% with respect to the total content (100 mass%) of the polyfunctional epoxy compound and the difunctional aromatic epoxy compound.

2. 2. The negative photosensitive composition according to claim 1, wherein a content ratio of the difunctional aromatic epoxy compound is 0.7 to 8 mass% with respect to a 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 of claim 3 , wherein the difunctional aromatic epoxy compound comprises a bisphenol epoxy monomer.

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

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

7. A method for manufacturing a hollow structural body having a recess and a top plate portion that closes an opening surface of the recess, comprising the steps of: A method for producing a hollow structural member, comprising forming the top plate portion using the negative photosensitive composition according to claim 1 or 2.

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

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

Images