Negative-type photosensitive resin composition, method for manufacturing hollow structure, and method for forming pattern

Abstract

The present invention uses a negative-type photosensitive resin composition that includes a bisphenol novolac epoxy resin and a cationic polymerization initiator. The invention is characterized in that the weight-average molecular weight of the bisphenol novolac epoxy resin is at least 4000. A hollow structure (100) comprises a support body (10), a first cover layer (3), and a second cover layer (40) (top panel section), The hollow structure is configured so that a hollow section (50) is provided between the support body (10) and the first cover layer (30), and a plurality of holes (35) that penetrate from the hollow section (50) to the top panel section are formed in the first cover layer (30). This negative-type photosensitive resin composition is suitable as a photosensitive material to be used to form the top panel section of the hollow structure. With this negative-type photosensitive resin composition, regardless of manufacturing process conditions, a resin film can be stably formed on the first cover layer (30) having the holes (35), without the resin film flowing through the holes (35) of the first cover layer (30) into the hollow section (50).

Description

Negative photosensitive resin composition, method for producing hollow structure, and pattern formation method

[0001] The present invention relates to a negative-type photosensitive resin composition, a method for manufacturing a hollow structure, and a pattern formation method. This application claims priority based on Japanese Patent Application No. 2022-170652, filed in Japan on October 25, 2022, the contents of which are incorporated herein by reference.

[0002] In recent years, the performance of microelectronic devices such as surface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters has been improving. Packages that encapsulate such microelectronic devices have hollow structures to ensure the propagation of surface acoustic waves and the mobility of movable parts of the electronic devices. In the future, there will be an increasing demand for miniaturization of packages with hollow structures, especially for smartphones and other devices that handle high frequencies.

[0003] In miniaturizing a package having a hollow structure, the size of the cover that covers the microelectronic device becomes an issue. To address this issue in miniaturizing the package, a covering method called TFP (Thin Film Package) has been proposed (see, for example, Patent Document 1 or Non-Patent Document 1).

[0004] 3 shows one embodiment of a hollow structure for housing a microelectronic device. The hollow structure 100 includes a support 10, a microelectronic device 20 disposed on the support 10, a first cover layer 30 formed on the support 10 and covering the microelectronic device 20, and a second cover layer 40 (top plate portion) covering the first cover layer 30. A hollow portion 50 (cavity) is provided between the support 10 and the first cover layer 30. A region of the first cover layer 30 that forms the top surface of the hollow portion 50 has a plurality of holes 35 that penetrate from the hollow portion 50 to the second cover layer 40. In the hollow structure 100, bumps 60 are provided on the support 10 along the outer periphery of the hollow portion 50.

[0005] 3, the second cover layer 40 mechanically strengthens the device or improves the airtightness of the hollow portion 50. The use of a resin composition as the material for this second cover layer 40 is being considered.

[0006] Special Publication No. 2016-516325

[0007] Technological Innovations in SAW Components for Frontend Modules with High Function Density; 7th International Symposium on Acoustic Wave Devices for Future Mobile Communication Systems; Abstracts, March 6-7, 2018, Chiba University

[0008] As packages having hollow structures become smaller and wiring densities increase, it is necessary to increase the adhesion strength between the layers constituting the hollow structure and between each layer and the bumps, and the conditions for the manufacturing process to achieve this have been studied. However, in the hollow structure 100, when a resin composition is used as the material for the second cover layer 40, a problem occurs in that the resin composition flows through the multiple holes 35 and falls into the hollow portion 50, depending on the baking conditions of the manufacturing process, for example. The present invention has been made in consideration of the above circumstances, and aims to provide a negative-type photosensitive resin composition that can stably form a resin film on a cover layer having holes without flowing through the holes in the cover layer and falling into the hollow portion, regardless of the manufacturing process conditions, as well as a method for manufacturing a hollow structure and a method for forming a pattern using the negative-type photosensitive resin composition.

[0009] In order to solve the above problems, the present invention employs the following configuration: That is, a first aspect of the present invention is a negative photosensitive resin composition containing a bisphenol novolac epoxy resin and a cationic polymerization initiator, wherein the weight-average molecular weight of the bisphenol novolac epoxy resin is 4,000 or more.

[0010] A second aspect of the present invention is a method for manufacturing a hollow structure comprising a support, a cover layer formed on the support, and a top plate portion covering the cover layer, wherein a hollow portion is provided between the support and the cover layer, and a hole penetrating from the hollow portion to the top plate portion is formed in the cover layer, characterized in that the top plate portion is formed using the negative-type photosensitive resin composition according to the first aspect.

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

[0012] According to the present invention, it is possible to provide a negative-type photosensitive resin composition that can stably form a resin film on a cover layer having holes, regardless of the conditions of the manufacturing process, without flowing through the holes in the cover layer and falling into the hollow portion, as well as a method for manufacturing a hollow structure and a pattern formation method using the negative-type photosensitive resin composition.

[0013] 1 is a GPC chart of a bisphenol A novolac epoxy resin before purification. FIG. 2 is a GPC chart of a bisphenol A novolac epoxy resin after purification. FIG. 3 is a cross-sectional view showing one embodiment of a hollow structure for housing a microelectronic device.

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

[0015] (Negative Photosensitive Resin Composition) The negative photosensitive resin composition of this embodiment contains a bisphenol novolac epoxy resin and a cationic polymerization initiator. The bisphenol novolac epoxy resin used here has a weight-average molecular weight of 4000 or more. When a photosensitive resin film is formed using this negative photosensitive resin composition and the photosensitive resin film is selectively exposed to light, the cationic moiety of the cationic polymerization initiator decomposes in the exposed portions of the photosensitive resin film to generate an acid. The acid then causes ring-opening polymerization of the epoxy groups in the bisphenol novolac epoxy resin, reducing the solubility of the bisphenol novolac epoxy resin in a developer containing an organic solvent (organic developer). However, the solubility of the bisphenol novolac epoxy resin in an organic developer remains unchanged in the unexposed portions of the photosensitive resin film, resulting in a difference in solubility in an organic developer between the exposed and unexposed portions of the photosensitive resin film. Therefore, when the photosensitive resin film is developed with an organic developer, the unexposed areas are dissolved and removed, forming a negative pattern.

[0016] This negative-type photosensitive resin composition is particularly suitable as a material for forming the top plate of a hollow structure including a support, a cover layer formed on the support, and a top plate covering the cover layer, with a hollow portion provided between the support and the cover layer, and holes formed in the cover layer that extend from the hollow portion to the top plate. For example, this negative-type photosensitive resin composition is particularly suitable as a material for the second cover layer 40 in the hollow structure 100 shown in FIG.

[0017] <Bisphenol Novolac Epoxy Resin> The negative photosensitive resin composition of this embodiment contains a bisphenol novolac epoxy resin (hereinafter also referred to as "component (P0)") having a weight-average molecular weight of 4,000 or more. Examples of bisphenol novolac epoxy resins include polyfunctional epoxy resins produced by reacting bisphenol novolac resin with epichlorohydrin, and polyfunctional epoxy resins obtained by novolaking bisphenol glycidyl ether. Among these, bisphenol A novolac epoxy resins are preferably used because of their easy availability. Note that component (P0) includes not only polyfunctional epoxy resins in which the reaction has progressed sufficiently, but also those in which the reaction with epichlorohydrin has not progressed sufficiently or those in which novolakization has not been sufficient, such as bisphenol epoxy monomers such as bisphenol monoglycidyl ether and bisphenol diglycidyl ether.

[0018] A preferred example of the bisphenol A novolac epoxy resin is a resin represented by the following general formula (Ap-0).

[0019] [In formula (Ap-0), R ｐ１ and R ｐ２ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ｐ１ may be the same or different. ｐ２ may be the same or different. １ is an integer from 1 to 5. ＥＰis an epoxy group-containing group. ＥＰ may be the same or different from each other.

[0020] In the formula (Ap-0), R ｐ１ , R ｐ２ The alkyl group having 1 to 5 carbon atoms is, for example, a linear, branched, or cyclic alkyl group having 1 to 5 carbon atoms. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group, and examples of the cyclic alkyl group include a cyclobutyl group and a cyclopentyl group. Among these, R ｐ１ , R ｐ２ is preferably a hydrogen atom or a linear or branched alkyl group, more preferably a hydrogen atom or a linear alkyl group, and particularly preferably a hydrogen atom or a methyl group. ｐ１ may be the same or different. ｐ２ may be the same as or different from each other.

[0021] In the formula (Ap-0), n １ is an integer of 1 to 5, preferably 2 or 3, and more preferably 2.

[0022] In formula (Ap-0), R ＥＰ is an epoxy group-containing group. ＥＰThe epoxy group-containing group is not particularly limited, and examples thereof include a group consisting of only epoxy groups; a group consisting of only alicyclic epoxy groups; and a group having an epoxy group or alicyclic epoxy group and a divalent linking group. An alicyclic epoxy group is an alicyclic group having an oxacyclopropane structure, which is a three-membered ring ether, specifically a group having an alicyclic group and an oxacyclopropane structure. The alicyclic group that forms the basic skeleton of the alicyclic epoxy group may be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of polycyclic alicyclic groups include norbornyl, isobornyl, tricyclononyl, tricyclodecyl, and tetracyclododecyl groups. The hydrogen atoms of these alicyclic groups may be substituted with alkyl groups, alkoxy groups, hydroxyl groups, or the like. In the case of a group having an epoxy group or an alicyclic epoxy group and a divalent linking group, it is preferable that the epoxy group or the alicyclic epoxy group is bonded via the divalent linking group bonded to an oxygen atom (—O—) in the formula.

[0023] 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.

[0024] Regarding the divalent hydrocarbon group which may have a substituent: The divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group in the divalent hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0025] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specifically, a methylene group [—CH ２-], ethylene group [-(CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, even more preferably 2 to 4 carbon atoms, and most preferably 2 or 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, -CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２-, -CH ２ CH (CH ３ ) CH ２ CH ２ Examples of alkyl groups include alkyl tetramethylene groups such as -, etc. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0026] Examples of the aliphatic hydrocarbon group containing a ring in its structure include alicyclic hydrocarbon groups (groups in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0027] The aromatic hydrocarbon group in the divalent hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having (4n+2) π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene groups or heteroarylene groups); groups in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., groups in which one further hydrogen atom has been removed from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, or 2-naphthylethyl group). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 or 2, and particularly preferably 1 carbon atom.

[0028] The divalent hydrocarbon group may have a substituent. The linear or branched aliphatic hydrocarbon group as the divalent hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0029] The alicyclic hydrocarbon group in the aliphatic hydrocarbon group containing a ring in its structure as a divalent hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, and preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. In the alicyclic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, and -S(=O) ２ -, -S(=O) ２ —O— is preferred.

[0030] In the aromatic hydrocarbon group as a divalent hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the alicyclic hydrocarbon group.

[0031] Regarding the divalent linking group containing a hetero atom: The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom or a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

[0032] In the divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -O-C(=O)-O-; -C(=O)-NH-, -NH-, -NH-C(=O)-O-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group); -S-, -S(=O) ２ -, -S(=O) ２ -O-, general formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ , -[Y ２１ -C(=O)-O] ｍ” -Y ２２ - or -Y ２１ -OC(=O)-Y ２２ -, wherein Y ２１ and Y ２２ are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -NH-, -NH-C(=O)-O-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. Formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C(=O)-O] ｍ” -Y ２２ - or -Y ２１ -OC(=O)-Y ２２ -Middle, Y２１ and Y ２２ are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same as the "divalent hydrocarbon group which may have a substituent" listed above in the description of the divalent linking group. Y ２１ As Y, a linear aliphatic hydrocarbon group is preferred, a linear alkylene group is more preferred, a linear alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or an ethylene group is particularly preferred. ２２ is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. ２１ -C(=O)-O] ｍ” -Y ２２ In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, ２１ -C(=O)-O] ｍ” -Y ２２ The group represented by - includes the group represented by the formula -Y ２１ -C(=O)-O-Y ２２ Among them, groups represented by the formula -(CH ２ ) ａ’ -C(=O)-O-(CH ２ ) ｂ’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0033] Among them, R ＥＰ The epoxy group-containing group in is preferably a glycidyl group.

[0034] In this specification and claims, the molecular weight of the (P0) component is expressed as a weight average molecular weight (Mw) and a number average molecular weight (Mn) in terms of polystyrene as measured by gel permeation chromatography (GPC).

[0035] The weight-average molecular weight (Mw) of the (P0) component contained in the negative photosensitive resin composition of this embodiment is 4000 or more, preferably 4000 to 8000, and more preferably 4000 to 6000. If the weight-average molecular weight of the (P0) component is 4000 or more, when producing a hollow structure, regardless of the conditions of the production process, the resin film can be stably formed on the cover layer having holes without flowing through the holes and falling into the hollow portion. Furthermore, interlayer delamination with the cover layer is less likely to occur. On the other hand, if the weight-average molecular weight of the (P0) component is equal to or less than the upper limit of the above-mentioned preferred range, the negative photosensitive resin composition can be easily applied to the cover layer, and the strength of the cured film formed can be sufficiently increased.

[0036] As mentioned above, the bisphenol epoxy monomer refers to a monomer including bisphenol monoglycidyl ether and bisphenol diglycidyl ether, and has a molecular weight of 500 or less.

[0037] The content of bisphenol epoxy monomer in the bisphenol novolac epoxy resin (component (P0)) contained in the negative photosensitive resin composition of this embodiment is preferably 2 mass% or less, more preferably 1.5 mass% or less, relative to the total mass of component (P0), and the lower the content of bisphenol epoxy monomer in component (P0), the better. When the content of bisphenol epoxy monomer is equal to or less than the upper limit of the above-mentioned preferred range, when producing a hollow structural body, regardless of the conditions of the production process, the resin film can be more stably formed on the cover layer having holes without flowing through the holes and falling into the hollow portion.

[0038] The molecular weight dispersity (Mw / Mn) of the component (P0) is preferably 2.0 or more and 4.0 or less, and more preferably 2.0 or more and 3.0 or less.

[0039] The epoxy equivalent of the component (P0) 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.

[0040] The epoxy equivalent of component (P0) can be measured by potentiometric titration as described in JIS K-7236. Examples of 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.

[0041] The content of the component (P0) in the negative photosensitive resin composition of this embodiment is preferably 70% by mass or more, more preferably 75 to 99% by mass, and even more preferably 80 to 98% by mass, based on the total mass (% by mass) of the solid content of the negative photosensitive resin composition.

[0042] <Cationic Polymerization Initiator> The cationic polymerization initiator (hereinafter also referred to as "component (I)") contained in the negative photosensitive resin composition of this embodiment is a compound that generates cations when irradiated with active energy rays such as ultraviolet rays, far ultraviolet rays, excimer laser light such as KrF or ArF, X-rays, electron beams, etc., and the cations can serve as polymerization initiators. Examples of the component (I) include onium borate salts (hereinafter also referred to as "component (I1)") and cationic polymerization initiators other than component (I1) (other cationic polymerization initiators).

[0043] <<Onium Borate Salt>> Onium borate salt (component (I1)) generates a relatively strong acid upon exposure. Therefore, by forming a pattern using a negative photosensitive resin composition containing component (I1), sufficient sensitivity is obtained and a good pattern is formed. Furthermore, the use of component (I1) also reduces the risk of toxicity and metal corrosion. Suitable examples of component (I1) include compounds represented by the following general formula (I1):

[0044] [In the formula, R ｂ０１ ~R ｂ０４are 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.

[0045] Anion part In the formula (I1), R ｂ０１ ~R ｂ０４ The aryl group in R preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples include naphthyl, phenyl, and anthracenyl groups, with the phenyl group being preferred because of its ease of availability. ｂ０１ ~R ｂ０４ The aryl group in formula (I1) may have a substituent. The substituent is not particularly limited, but is preferably a halogen atom, a hydroxyl group, an alkyl group (preferably a linear or branched alkyl group, preferably having 1 to 5 carbon atoms), or a halogenated alkyl group, more preferably a halogen atom or a halogenated alkyl group having 1 to 5 carbon atoms, and particularly preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. When the aryl group has a fluorine atom, the polarity of the anion moiety is increased, which is preferable. Among these, R in formula (I1) ｂ０１ ~R ｂ０４ As each of the groups, a fluorinated phenyl group is preferred, and a perfluorophenyl group is particularly preferred.

[0046] A preferred example of the anion moiety of the compound represented by formula (I1) is tetrakis(pentafluorophenyl)borate ([B(C ６ F ５ ) ４ ] － tetrakis[(trifluoromethyl)phenyl]borate ([B(C ６ H ４ CF ３ ) ４ ] － ); difluorobis(pentafluorophenyl)borate ([(C ６ F ５ ) ２ BF ２ ] －); trifluoro(pentafluorophenyl)borate ([(C ６ F ５ ) BF ３ ] － tetrakis(difluorophenyl)borate ([B(C ６ H ３ F ２ ) ４ ] － Among them, tetrakis(pentafluorophenyl)borate ([B(C ６ F ５ ) ４ ] － ) is particularly preferred.

[0047] Cation moiety In the formula (I1), Q ｑ＋ Suitable examples of the cation include sulfonium cations and iodonium cations, and the organic cations represented by the following general formulae (ca-1) to (ca-5) are particularly preferred.

[0048] [In the formula, R ２０１ ~R ２０７ , and R ２１１ ~R ２１２ R each independently represents an aryl group, a heteroaryl group, an alkyl group, or an alkenyl group, which may have a substituent. ２０１ ~R ２０３ , R ２０６ ~R ２０７ , R ２１１ ~R ２１２ may be bonded to each other to form a ring together with the sulfur atom in the formula. ２０８ ~R ２０９ R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ２１０ represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group. ２０１ represents —C(═O)— or —C(═O)—O—. ２０１ each independently represents an arylene group, an alkylene group, or an alkenylene group; x is 1 or 2. ２０１represents a (x+1)-valent linking group.

[0049] R ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２０１ ~R ２０７ , and R ２１１ ~R ２１２ Examples of the heteroaryl group in the formula (I) include those in which some of the carbon atoms constituting the aryl group have been substituted with heteroatoms. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of this heteroaryl group include a group in which one hydrogen atom has been removed from 9H-thioxanthene; and examples of the substituted heteroaryl group include a group in which one hydrogen atom has been removed from 9H-thioxanthen-9-one. R ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ , and R ２１１ ~R ２１２ The alkenyl group in R preferably has 2 to 10 carbon atoms. ２０１ ~R ２０７ , and R ２１０ ~R ２１２ Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an oxo group (═O), an aryl group, and groups represented by the following formulas (car-r-1) to (car-r-10):

[0050] [In the formula, R' ２０１ are each independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0051] In the above formulae (car-r-1) to (car-r-10), R'２０１ are each independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted chain alkyl group, or an optionally substituted chain alkenyl group.

[0052] Optionally substituted cyclic group: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or a cyclic aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0053] R' ２０１ The aromatic hydrocarbon group in R' is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. ２０１ Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group in R' include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms, or rings in which some of the hydrogen atoms constituting these aromatic rings or aromatic heterocycles are substituted with oxo groups or the like. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. ２０１Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic ring (an aryl group: for example, a phenyl group, a naphthyl group, or an anthracenyl group), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group), a group in which one hydrogen atom has been removed from a ring in which some of the hydrogen atoms constituting the aromatic ring have been substituted with an oxo group or the like (for example, anthraquinone), and a group in which one hydrogen atom has been removed from an aromatic heterocycle (for example, 9H-thioxanthene or 9H-thioxanthen-9-one). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 or 2, and particularly preferably 1.

[0054] R' ２０１Examples of the cyclic aliphatic hydrocarbon group in the formula (I) include aliphatic hydrocarbon groups containing a ring within their structure. Examples of aliphatic hydrocarbon groups containing a ring within their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed within a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group. Preferred monocyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a monocycloalkane. Preferred monocycloalkanes have 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. Preferred polycyclic alicyclic hydrocarbon groups are groups in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a polycyclic skeleton of a fused ring system, such as a cyclic group having a steroid skeleton.

[0055] Among them, R' ２０１ The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0056] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [—CH ２ -], ethylene group [-(CH ２ ) ２-], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, specifically, —CH(CH ３ ) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ alkylethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ alkyltrimethylene groups such as -; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0057] A chain alkyl group which may have a substituent: R' ２０１ The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specific examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, heneicosyl, and docosyl groups. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0058] A chain alkenyl group which may have a substituent: R' ２０１ The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl, propenyl (allyl), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, and 2-methylpropenyl groups. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0059] R' ２０１ Examples of the substituent in the cyclic group, chain alkyl group or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, an oxo group, the above-mentioned R' ２０１ Examples of the groups include a cyclic group, an alkylcarbonyl group, and a thienylcarbonyl group.

[0060] Among them, R' ２０１ is preferably a cyclic group which may have a substituent, or a chain alkyl group which may have a substituent.

[0061] R ２０１ ~R ２０３ , R ２０６ ~R ２０７ , R ２１１ ~R ２１２ When they are bonded to each other to form a ring together with the sulfur atom in the formula, they are not substituted with heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, or with carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0062] In the formula (ca-3), R ２０８ ~R ２０９ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups, they may be bonded to each other to form a ring.

[0063] In the formula (ca-3), R ２１０represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted —SO ２ -containing cyclic group. ２１０ The aryl group in R is an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. ２１０ The alkyl group in R is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms.

[0064] In the formulas (ca-4) and (ca-5), Y ２０１ each independently represents an arylene group, an alkylene group, or an alkenylene group. ２０１ The arylene group in ２０１ Examples of the aromatic hydrocarbon group in the above formula include groups in which one hydrogen atom has been removed from the aryl groups exemplified in the formula Y. ２０１ The alkylene group and alkenylene group in R' ２０１ Examples of the chain alkyl group and the chain alkenyl group include groups in which one hydrogen atom has been removed from the groups exemplified above as the chain alkyl group and the chain alkenyl group.

[0065] In the formulas (ca-4) and (ca-5), x is 1 or 2. ２０１ is a (x+1)-valent linking group, i.e., a divalent or trivalent linking group. ２０１ The divalent linking group in the formula (Ap-0) is preferably a divalent hydrocarbon group which may have a substituent. ＥＰ The same groups as the optionally substituted divalent hydrocarbon groups exemplified by W are preferred. ２０１ The divalent linking group in may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group, or a group consisting of only an arylene group is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferred. ２０１ The trivalent linking group in ２０１Examples of the divalent linking group include a group in which one hydrogen atom has been removed from the divalent linking group shown in the formula: and a group in which the divalent linking group is further bonded to the divalent linking group shown in the formula: ２０１ The trivalent linking group in the formula (I) is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0066] 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).

[0067]

[0068] [In the formula, R” ２０１ is a hydrogen atom or a substituent. The substituent includes the above-mentioned R ２０１ ~R ２０７ and R ２１０ ~R ２１２ The substituents are the same as those exemplified as the substituents that may be possessed by

[0069] As the cation represented by the formula (ca-1), cations represented by the following general formulae (ca-1-25) to (ca-1-35) are also preferred.

[0070]

[0071] [In the formula, R' ２１１ is an alkyl group. ｈａｌ is a hydrogen atom or a halogen atom.

[0072] As the cation represented by the formula (ca-1), cations represented by the following chemical formulas (ca-1-36) to (ca-1-48) are also preferred.

[0073]

[0074] As the cation represented by the formula (ca-1), cations having a benzoylphenyl group represented by the following chemical formulas (ca-1-49) to (ca-1-54) are also preferred.

[0075]

[0076] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0077] 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).

[0078]

[0079] 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).

[0080]

[0081] As the cation represented by the formula (ca-5), cations represented by the following general formulas (ca-5-1) to (ca-5-3) are also preferred.

[0082] [In the formula, R' ２１２ is an alkyl group or a hydrogen atom. ２１１ is an alkyl group.

[0083] Among the above, the cation part [(Q ｑ＋ ) １／ｑ is preferably a cation represented by general formula (ca-1), more preferably a cation represented by each of formulas (ca-1-1) to (ca-1-54), and even more preferably a cation represented by each of formulas (ca-1-49) to (ca-1-54).

[0084] <<Other Cationic Polymerization Initiators>> Examples of cationic polymerization initiators other than the component (I1) include compounds represented by the following general formula (I2-1) or (I2-2) (hereinafter referred to as “component (I2)”); and compounds represented by the following general formula (I3-1) or (I3-2) (hereinafter referred to as “component (I3)”).

[0085] Regarding the component (I2): The component (I2) is a compound represented by the following general formula (I2-1) or (I2-2): The component (I2) generates a relatively strong acid upon exposure. Therefore, when a pattern is formed using a negative-type photosensitive resin composition containing the component (I), sufficient sensitivity is obtained and a good pattern is formed.

[0086] [In the formula, R ｂ０５ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０５ may be the same or different from each other. q is an integer of 1 or more, and Q ｑ＋ is a q-valent organic cation.

[0087] [In the formula, R ｂ０６ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０６ may be the same or different from each other. q is an integer of 1 or more, and Q ｑ＋ is a q-valent organic cation.

[0088] Anion part In the formula (I2-1), R ｂ０５ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０５ may be the same or different. ｂ０５ The fluorinated alkyl group in the formula (I) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms. Specific examples include alkyl groups having 1 to 5 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms. ｂ０５ As the alkyl group, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms is more preferred, and a fluorine atom, a trifluoromethyl group or a pentafluoroethyl group is even more preferred.

[0089] The anion moiety of the compound represented by formula (I2-1) is preferably represented by the following general formula (b0-2a).

[0090] [In the formula, R ｂｆ０５ represents a fluorinated alkyl group which may have a substituent. １ is an integer from 1 to 5.

[0091] In formula (b0-2a), R ｂｆ０５ The optionally substituted fluorinated alkyl group in R ｂ０５ In formula (b0-2a), nb is the same as the optionally substituted fluorinated alkyl group listed above. １ is preferably an integer of 1 to 4, more preferably an integer of 2 to 4, and most preferably 3.

[0092] In the formula (I2-2), R ｂ０６ is a fluorine atom or a fluorinated alkyl group which may have a substituent. ｂ０６ may be the same or different. ｂ０６ The fluorinated alkyl group in the formula (I) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms. Specific examples include alkyl groups having 1 to 5 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms. ｂ０６ As the alkyl group, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms is more preferred, and a fluorine atom is even more preferred.

[0093] In formula (I2-1) and formula (I2-2), q is an integer of 1 or more, and Q ｑ＋ is a q-valent organic cation. ｑ＋ As the group, Q in the above formula (I1) ｑ＋ Among them, cations represented by general formula (ca-1) are preferred, and cations represented by formulas (ca-1-1) to (ca-1-54) are more preferred.

[0094] Regarding the component (I3): The component (I3) is a compound represented by the following general formula (I3-1) or (I3-2).

[0095] [In the formula, R ｂ１１ ~Rｂ１２ 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.

[0096] {Component (I3-1)} Anion portion In formula (I3-1), R ｂ１２ is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom, and is ２０１ Among the cyclic groups, chain alkyl groups, and chain alkenyl groups in the explanation of R, those which have no substituent or have a substituent other than a halogen atom are exemplified. ｂ１２ is preferably a chain alkyl group which may have a substituent other than a halogen atom, or an aliphatic cyclic group which may have a substituent other than a halogen atom. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent other than a halogen atom); or a group in which one or more hydrogen atoms have been removed from camphor, etc. ｂ１２ The hydrocarbon group may have a substituent other than a halogen atom, and examples of the substituent include R ｂ１１ Examples include the same substituents other than halogen atoms as those which may be possessed by the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in (1). Here, the phrase "may have a substituent other than halogen atoms" not only excludes cases in which a substituent consisting of only halogen atoms is possessed, but also excludes cases in which a substituent containing at least one halogen atom is possessed (for example, cases in which the substituent is a fluorinated alkyl group, etc.).

[0097] Specific examples of preferred anion moieties of the component (I3-1) are shown below.

[0098]

[0099] Cation moiety In formula (I3-1), M ｍ＋ is an m-valent organic cation. ｍ＋ Suitable examples of the organic cation include the same cations as those represented by the general formulas (ca-1) to (ca-5) above, and among these, the cation represented by the general formula (ca-1) above is more preferred. ２０１ , R ２０２ , R ２０３ A sulfonium cation in which at least one of the groups is an organic group having 16 or more carbon atoms (aryl group, heteroaryl group, alkyl group, or alkenyl group) which may have a substituent is particularly preferred, as it improves resolution and roughness characteristics. The substituent that the organic group may have is the same as above, and examples thereof include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an oxo group (═O), an aryl group, and groups represented by the above formulas (car-r-1) to (car-r-10). The number of carbon atoms in the organic group (aryl group, heteroaryl group, alkyl group, or alkenyl group) is preferably 16 to 25, more preferably 16 to 20, and particularly preferably 16 to 18, and such M ｍ＋ Suitable examples of the organic cation include the cations represented by the above formulas (ca-1-25), (ca-1-26), (ca-1-28) to (ca-1-36), (ca-1-38), (ca-1-46), and (ca-1-47), and among these, the cation represented by the above formula (ca-1-29) is particularly preferred.

[0100] {Component (I3-2)} Anion portion In formula (I3-2), R ｂ１１ is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom, and is ２０１Among the cyclic groups, chain alkyl groups and chain alkenyl groups in the explanation of (1), those which have no substituent or those which have a substituent other than a halogen atom are exemplified.

[0101] Among these, R ｂ１１ is preferably an aromatic hydrocarbon group which may have a substituent other than a halogen atom, an aliphatic cyclic group which may have a substituent other than a halogen atom, or a chain alkyl group which may have a substituent other than a halogen atom. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a lactone-containing cyclic group, an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the following general formulas (y-al-1) to (y-al-7). In the following general formulas (y-al-1) to (y-al-7), R in the above formula (I3-2) ｂ１１ The bond to V' in the following general formulae (y-al-1) to (y-al-7) is １０１ is.

[0102] [In the formula, V' １０１ is a single bond or an alkylene group having 1 to 5 carbon atoms. １０２ is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0103] 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.

[0104] V' １０１ and V' １０２ The alkylene group in V' may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group. １０１ and V' １０２ Specific examples of the alkylene group in ２ -]; -CH(CH ３) -, -CH(CH ２ CH ３ ) -, -C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ ) -, -C(CH ３ ) (CH ２ CH ２ CH ３ ) -, -C(CH ２ CH ３ ) ２ alkylmethylene groups such as -; ethylene groups [-CH ２ CH ２ -]; -CH(CH ３ ) CH ２ -, -CH(CH ３ ) CH(CH ３ ) -, -C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ ) CH ２ -, etc.; a trimethylene group (n-propylene group) [—CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ an alkyltrimethylene group such as -; a tetramethylene group [-CH ２ CH ２ CH ２ CH ２ -]; -CH(CH ３ ) CH ２ CH ２ CH ２ -, -CH ２ CH (CH ３ ) CH ２ CH ２ -, etc.; an alkyltetramethylene group such as a pentamethylene group [—CH ２ CH ２ CH ２ CH ２ CH ２ -]. Also, V'１０１ or V' １０２ In the above formula, some methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by R' ２０１ A divalent group obtained by further removing one hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group) of the above formula (I) is preferred, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferred.

[0105] The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group. The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl groups.

[0106] R ｂ１１ is preferably a cyclic group which may have a substituent other than a halogen atom. Specific examples of preferred anion moieties of component (I3-2) are shown below.

[0107]

[0108] Cation moiety In formula (I3-2), M ｍ＋ is an m-valent organic cation, and M in the formula (I3-1) ｍ＋ is the same as:

[0109] Furthermore, in terms of increasing the elasticity of the resin film and facilitating the formation of a fine structure without residue, component (I) is preferably a cationic polymerization initiator that generates an acid with a pKa (acid dissociation constant) of -5 or less upon exposure. By using a cationic polymerization initiator that generates an acid with a pKa of more preferably -6 or less, and even more preferably -8 or less, high sensitivity to exposure can be achieved. The lower limit of the pKa of the acid generated by component (I) is preferably -15 or more. By using a cationic polymerization initiator that generates an acid with such a suitable pKa, high sensitivity can be achieved. Here, "pKa (acid dissociation constant)" refers to a commonly used index indicating the acid strength of a target substance. Note that the pKa in this specification is a value at a temperature condition of 25°C. The pKa value can be determined by measurement using known techniques. Alternatively, a calculated value using known software such as "ACD / Labs" (trade name, manufactured by Advanced Chemistry Development) can also be used.

[0110] As the component (I), one type may be used alone, or two or more types may be used in combination. In the negative photosensitive resin composition used in this embodiment, the component (I) is preferably at least one type selected from the group consisting of the component (I1), the component (I2), and the component (I3), and it is more preferable to use the component (I1).

[0111] In the negative-type photosensitive resin composition used in this embodiment, the content of component (I) is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, even more preferably 0.15 to 3 parts by mass, and particularly preferably 0.2 to 1 part by mass, based on 100 parts by mass of the total parts by mass of component (P0). When the content of component (I) is at least the lower limit of the preferred range, sufficient sensitivity is obtained, and the lithography properties of the pattern are further improved. In addition, the strength of the cured resin film is further increased. On the other hand, when the content is at most the upper limit of the preferred range, sensitivity is appropriately controlled, making it easier to obtain a pattern with a good shape.

[0112] <Other Components> The negative-tone photosensitive resin composition of this embodiment may contain other components as needed, in addition to the above-described component (P0) and component (I). If desired, the negative-tone photosensitive resin composition of this embodiment may appropriately contain miscible additives, such as epoxy group-containing compounds other than component (P0), silane coupling agents, sensitizer components, metal oxides (MO), solvents, additional resins for improving film performance, dissolution inhibitors, basic compounds, plasticizers, stabilizers, colorants, and antihalation agents.

[0113] The negative photosensitive resin composition of this embodiment may contain an epoxy group-containing compound other than component (P0). Examples of the epoxy group-containing compound other than component (P0) include bisphenol epoxy resins (bisphenol A epoxy resins, bisphenol F epoxy resins), acrylic resins, and aliphatic epoxy resins.

[0114] Furthermore, suitable examples of epoxy group-containing compounds other than the component (P0) include compounds represented by the following general formula (m-01) (hereinafter, this compound may also be referred to as "component (m01)").

[0115] [In the formula, R ＥＰ is an epoxy group-containing group. ＥＰ may be the same or different from each other.

[0116] In the formula (m-01), R ＥＰ is an epoxy group-containing group, and R ＥＰ is the same as:

[0117] Examples of commercially available products that can be used as the component (m01) include the TEPIC series (manufactured by Nissan Chemical Industries, Ltd.), such as TEPIC, TEPIC-VL, TEPIC-PAS, TEPIC-G, TEPIC-S, TEPIC-SP, TEPIC-SS, TEPIC-HP, TEPIC-L, TEPIC-FL, and TEPIC-UC; MA-DGIC, DA-MGIC, and TOIC (manufactured by Shikoku Chemical Industries, Ltd.).

[0118] The (m01) component may be used alone or in combination of two or more. In the negative-type photosensitive resin composition used in this embodiment, the content of the (m01) component is preferably 1 to 15 parts by mass, and more preferably 3 to 10 parts by mass, based on 100 parts by mass of the total parts by mass of the (P0) component. Alternatively, in the negative-type photosensitive resin composition used in this embodiment, the content of the (m01) component is preferably 1 to 25 parts by mass, and more preferably 3 to 20 parts by mass, based on 100 parts by mass of the total parts by mass of the (P0) component.

[0119] Furthermore, suitable examples of epoxy group-containing compounds other than the component (P0) include compounds represented by the following general formula (m-02) (hereinafter, this compound may also be referred to as "component (m02)").

[0120] [In the formula, n ２ is an integer of 1 to 4. * indicates a bond.

[0121] In the formula (m-02), n ２ is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2.

[0122] Examples of the (m02) component include compounds in which a plurality of partial structures represented by the general formula (m-02) are bonded via a divalent linking group or a single bond. Among these, compounds in which a plurality of partial structures represented by the general formula (m-02) are bonded via a divalent linking group are preferred. The divalent linking group here is not particularly limited, but examples of suitable divalent linking groups include divalent hydrocarbon groups which may have a substituent and divalent linking groups which contain a heteroatom. The divalent hydrocarbon groups which may have a substituent and divalent linking groups which contain a heteroatom here include R in the above formula (Ap-0). ＥＰ The divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom which are described in (epoxy group-containing group) are the same as those described above. Among these, the divalent linking group containing a hetero atom is preferred. ２１ a group represented by —C(═O)—O—, —C(═O)—O—Y ２１ A group represented by - is more preferred. ２１As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferred, a straight-chain alkylene group is more preferred, a straight-chain alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred.

[0123] Commercially available products that can be used as the component (m02) include, for example, ADEKA RESIN EP-4080S, EP-4085S, and EP-4088S (all manufactured by ADEKA Corporation); CELLOXIDE 2021P, CELLOXIDE 2081, CELLOXIDE 2083, CELLOXIDE 2085, CELLOXIDE 8000, CELLOXIDE 8010, EHPE-3150, EPOLEAD PB 3600, and EPOLEAD PB 4700 (all manufactured by Daicel Corporation); and DENACOL EX-211L, EX-212L, EX-214L, EX-216L, EX-321L, EX-850L (all manufactured by Nagase ChemteX Corporation); Epocalic THI-DE, Epocalic THI-DE-102, Epocalic THI-DE-103 (all manufactured by ENEOS Corporation); and the like.

[0124] The component (m02) may be used alone or in combination of two or more. In the negative photosensitive resin 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 component (P0).

[0125] Furthermore, as the epoxy group-containing compound other than the component (P0), for example, a compound represented by the following chemical formula (m-03-1) or a compound represented by the following chemical formula (m-03-2) (hereinafter these may be collectively referred to as "component (m03)") may be used. An example of a commercially available product that can be used as the compound represented by the following chemical formula (m-03-1) is TECHMORE VG-3101L (manufactured by Printec Co., Ltd.). An example of a commercially available product that can be used as the compound represented by the following chemical formula (m-03-2) is Showfree (registered trademark) BATG (manufactured by Showa Denko K.K.).

[0126]

[0127] In the negative-type photosensitive resin composition used in this embodiment, the content of the component (m03) is preferably 1 to 15 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 component (P0).

[0128] The negative-type photosensitive resin composition of this embodiment may further contain an adhesion aid to improve adhesion to the substrate. A silane coupling agent is preferred as this adhesion aid. That is, the negative-type photosensitive resin composition of this embodiment may further contain a silane coupling agent. Examples of silane coupling agents include silane coupling agents having reactive substituents such as carboxy groups, methacryloyl groups, isocyanate groups, and epoxy groups. Specific examples include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. One type of silane coupling agent may be used alone, or two or more types may be used in combination. When a silane coupling agent is included, the content is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 3 parts by mass, per 100 parts by mass of component (P0). When the content of the silane coupling agent is within the above-mentioned preferred range, the strength of the cured film is further increased, and in addition, the adhesion between the cured film and the substrate is further strengthened.

[0129] The negative-type photosensitive resin composition of this embodiment may further contain a sensitizer component. The sensitizer component is not particularly limited as long as it is capable of absorbing energy from exposure and transmitting that energy to another substance. Specific examples of the sensitizer component include benzophenone-based photosensitizers such as benzophenone and p,p'-tetramethyldiaminobenzophenone; carbazole-based photosensitizers; acetophenone-based photosensitizers; naphthalene-based photosensitizers such as 1,5-dihydroxynaphthalene; phenol-based photosensitizers; anthracene-based photosensitizers such as 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, and 9-ethoxyanthracene; and known photosensitizers such as biacetyl, eosin, rose bengal, pyrene, phenothiazine, and anthrone. One type of sensitizer component may be used alone, or two or more types may be used in combination. When a sensitizer component is included, its content is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of component (P0). When the content of the sensitizer component is within the above-mentioned preferred range, sensitivity and resolution can be further improved.

[0130] The negative photosensitive resin composition of this embodiment may further contain a metal oxide (MO) (hereinafter also referred to as "(MO) component"), since this facilitates the formation of a cured film with enhanced strength. Furthermore, the inclusion of an (MO) component enables the formation of a high-resolution pattern with a favorable shape. Examples of the (MO) component include oxides of metals such as silicon (metallic silicon), titanium, zirconium, and hafnium. Among these, silicon oxide is preferred, and among these, silica is particularly preferred. Furthermore, the (MO) component is preferably in the form of particles. Such a particulate (MO) component is preferably composed of particles having a volume average particle diameter of 5 to 40 nm, more preferably of particles having a volume average particle diameter of 5 to 30 nm, and even more preferably of particles having a volume average particle diameter of 10 to 20 nm. When the volume average particle diameter of the (MO) component is equal to or greater than the lower limit of the preferred range, the strength of the cured film is likely to be enhanced. On the other hand, when the content is equal to or less than the upper limit of the preferred range, residues are less likely to be generated during pattern formation, making it easier to form higher-resolution patterns. In addition, the transparency of the resin film is improved. The particle size of the (MO) component can be appropriately selected depending on the exposure light source. It is generally believed that particles having a particle size of 1 / 10 or less of the wavelength of light are virtually immune to the effects of light scattering. For this reason, when forming a microstructure by photolithography using i-line (365 nm), for example, it is preferable to use particles (particularly silica particles) having a primary particle size (volume average) of 10 to 20 nm as the (MO) component. One type of (MO) component may be used alone, or two or more types may be used in combination. When the (MO) component is included, its content is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, per 100 parts by mass of the (P0) component. When the (MO) component is included, its content is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, per 100 parts by mass of the (P0) component. When the (MO) component is included, its content is equal to or greater than the lower limit of the preferred range, the strength of the cured film is further increased. On the other hand, when it is equal to or less than the upper limit of the above-mentioned preferred range, the transparency of the resin film is further improved.

[0131] The negative photosensitive resin composition of this embodiment may further contain a solvent (hereinafter sometimes referred to as "component (S)"). Examples of component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; monoalkyl ethers or monoalkyl ethers of the polyhydric alcohols or the compounds having an ester bond such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether; Examples of the solvent include derivatives of polyhydric alcohols such as compounds having an ether bond, such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME), cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate, aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). The component (S) may be used alone or as a mixed solvent of two or more.

[0132] When the component (S) is contained, the amount used is not particularly limited and is set appropriately depending on the coating film thickness at a concentration that allows the negative photosensitive resin composition to be applied to a substrate or the like without dripping. For example, the component (S) can be used so that the solids concentration is 70% by mass or more, or 60% by mass or more. In addition, an embodiment that does not substantially contain the component (S) (i.e., an embodiment in which the solids concentration is 100% by mass) can also be employed.

[0133] (Laminate film) The laminate film of this embodiment is a laminate of a photosensitive resin composition layer made of the negative photosensitive resin composition of the above-described embodiment and a support film. Note that the laminate film may have a cover film disposed on the side of the photosensitive resin composition layer formed using the negative photosensitive resin composition opposite to the side on which the support film is present.

[0134] The laminate film of this embodiment can be produced, for example, by applying the negative-type photosensitive resin composition of the above-described embodiment to a support film, drying the composition to form a photosensitive resin composition layer, and then laminating a cover film on the photosensitive resin composition layer. The negative-type photosensitive resin composition can be applied to the substrate film using an appropriate method such as a blade coater, lip coater, comma coater, or film coater. The thickness of the photosensitive resin composition layer is preferably 100 μm or less, and more preferably 5 to 50 μm.

[0135] A known material can be used for the support film, such as a thermoplastic resin film. Examples of such thermoplastic resins include polyesters such as polyethylene terephthalate. The thickness of the base film is preferably 2 to 150 μm. A known material can be used for the cover film, such as a polyethylene film or a polypropylene film. The cover film is preferably a film that has a lower adhesive strength with the photosensitive resin composition layer than the support film. The thickness of the cover film is preferably 2 to 150 μm, more preferably 2 to 100 μm, and even more preferably 5 to 50 μm. The support film and cover film may be made of the same film material, or different film materials.

[0136] (Method for manufacturing hollow structure) The method for manufacturing a hollow structure of this embodiment is a method for manufacturing a hollow structure comprising a support, a cover layer formed on the support, and a top plate portion covering the cover layer, with a hollow portion provided between the support and the cover layer, and a hole formed in the cover layer that passes through the hollow portion to the top plate portion. This embodiment is characterized in that the top plate portion is formed using the negative-type photosensitive resin composition of the above-described embodiment.

[0137] For example, the manufacturing method of the hollow structure of this embodiment can be used to manufacture the hollow structure 100 shown in Fig. 3. As an example of the manufacturing method of the hollow structure 100, first, a microelectronic device 20 is placed on a support 10. The support 10 can be a substrate containing a material selected from glass and Si (silicon). The microelectronic device 20 can be a SAW filter, a BAW filter, or the like. Conducting wires (not shown) are connected to the microelectronic device 20.

[0138] Next, the microelectronic device 20 arranged on the support 10 is entirely covered with a sacrificial layer. The space occupied by this sacrificial layer corresponds to the hollow portion (cavity) 50. The sacrificial layer is formed using an organic material.

[0139] Next, the sacrificial layer is covered with a first cover layer 30. At the same time, the first cover layer 30 is provided so as to cover a part of the support 10 on the periphery of the sacrificial layer. The first cover layer 30 is made of a so-called TFP film, for example, SiO ２ (silicon dioxide), SixNy (silicon nitride) and Al ２ O ３ (aluminum oxide). The first cover layer 30 can be formed by sputtering, thermal evaporation, chemical vapor deposition, physical vapor deposition, pulsed laser deposition, molecular beam epitaxy, or the like.

[0140] Next, a hole pattern is machined in the first cover layer 30 so as to form a plurality of holes 35 penetrating to the sacrificial layer. The sacrificial layer is then removed through the plurality of holes 35. The sacrificial layer can be removed by means of wet etching or dry etching in an oxidizing atmosphere, or by ashing. Removal of the sacrificial layer forms a hollow portion 50 (cavity). The microelectronic device 20 is placed in the hollow portion 50 (cavity) without touching the first cover layer 30.

[0141] Next, the first cover layer 30 is covered with the second cover layer 40 (top plate portion). The negative photosensitive resin composition of the above-described embodiment is used as a material for forming this second cover layer 40 (top plate portion). Furthermore, the bumps 60 are arranged so as to contact the support 10 and the conductive wires exposed on the outer periphery of the first cover layer 30. To form the second cover layer 40, a photosensitive resin film is formed on the first cover layer 30 using the negative photosensitive resin composition of the above-described embodiment (step (i)). In step (i), the negative photosensitive resin composition of the above-described embodiment is first applied to the first cover layer 30 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 60 to 100°C, for example, followed by another baking treatment at a temperature of 100 to 200°C for 1 to 30 minutes to form a photosensitive resin film.

[0142] Next, the photosensitive resin film is exposed to light and developed to form vias for bumps. After the vias are formed, they are cured at a temperature of 100 to 200°C for 1 to 4 hours to form a cured film. Next, metal is sputtered at the bottom of the formed vias, and bumps can be formed by plating. In this manner, the hollow structure 100 can be manufactured.

[0143] In the method for manufacturing a hollow structure of the present embodiment described above, a negative photosensitive resin composition containing a bisphenol novolac epoxy resin having a weight-average molecular weight of 4000 or more and a cationic polymerization initiator is used to form the second cover layer 40. Therefore, regardless of the conditions of the manufacturing process, even if the temperature of the curing treatment is set high, the negative photosensitive resin composition, which is a photosensitive resin film, does not flow through the multiple holes 35 formed in the first cover layer 30 and fall into the hollow portion 50, and a resin film (second cover layer 40) can be stably formed on the first cover layer 30 having the holes 35.

[0144] According to this embodiment, the temperature of the curing process can be set higher than in the conventional case, thereby increasing the adhesion strength between the first cover layer 30 and the second cover layer 40, or between each layer and the bump 60.

[0145] (Pattern Forming Method) The pattern forming method of this embodiment includes the steps of forming a photosensitive resin film on a support using the negative photosensitive resin composition of the above-described embodiment (hereinafter referred to as the "film forming step"), exposing the photosensitive resin film to light (hereinafter referred to as the "exposure step"), and developing the exposed photosensitive resin film with a developer containing an organic solvent to form a negative pattern (hereinafter referred to as the "development step"). The pattern forming method of this embodiment can be performed, for example, as follows.

[0146] [Film Formation Step] First, the negative photosensitive resin 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 60 to 180° C. to form a photosensitive resin film. Note that the film formation step can also be performed by disposing the photosensitive resin composition layer of the above-described laminate film on the support.

[0147] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, silicon, silicon nitride, titanium, tantalum, lithium tantalate (LiTaO ３ ), niobium, lithium niobate (LiNbO ３ Examples of suitable materials include metal substrates such as palladium, titanium tungsten, copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0148] The pattern forming method of this embodiment is applicable to, for example, lithium tantalate (LiTaO ３ ) substrate, lithium niobate (LiNbO ３ ) is a useful method for substrates.

[0149] The thickness of the photosensitive resin film formed from the negative photosensitive resin composition is not particularly limited, but is preferably about 10 to 100 μm. The negative photosensitive resin composition of the above embodiment can provide good properties even when a thick film is formed.

[0150] [Exposure Step] Next, the formed photosensitive resin film is subjected to selective exposure using a known exposure device, for example, through a mask (mask pattern) on which a predetermined pattern has been formed, or by drawing using direct irradiation with an electron beam without using a mask pattern, and then, if necessary, baked (post-exposure bake (PEB)) at a temperature of 80 to 150°C for 40 to 1200 seconds, preferably 40 to 1000 seconds, and more preferably 60 to 900 seconds.

[0151] The wavelength used for exposure is not particularly limited, and radiation such as ultraviolet light having a wavelength of 300 to 500 nm, i-rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). Examples of radiation sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and argon gas lasers. Here, radiation refers to ultraviolet light, visible light, far ultraviolet light, X-rays, electron beams, and the like. The radiation dose varies depending on the type and amount of each component in the composition, the thickness of the coating film, and the like, but for example, when an ultra-high-pressure mercury lamp is used, it is 100 to 2000 mJ / cm. ２ is.

[0152] The exposure method for the photosensitive resin film may be a normal exposure (dry exposure) carried out in air or an inert gas such as nitrogen, or may be liquid immersion exposure (liquid immersion lithography).

[0153] The photosensitive resin film after the exposure step has high transparency, and for example, the haze value when irradiated with i-line (wavelength 365 nm) is preferably 3% or less, more preferably 1.0 to 2.5%. Thus, the photosensitive resin film formed using the negative photosensitive resin composition of the above-described embodiment has high transparency. Therefore, during exposure in pattern formation, light transmittance is increased, making it easier to obtain a negative pattern with good lithography properties. The haze value of the photosensitive resin film after such an exposure step is measured using a method in accordance with JIS K 7136 (2000).

[0154] [Development Step] Next, the photosensitive resin film after exposure is developed with a developer containing an organic solvent (organic developer). After development, a rinse treatment is preferably performed. If necessary, a bake treatment (post-bake) may be performed.

[0155] The organic solvent contained in the organic developer may be any solvent capable of dissolving the component (P0) (the component (P0) before exposure), and may be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0156] 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.

[0157] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate (PGMEA), ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, Pyrene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, milk Examples of the alkyl esters include ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.Among these, butyl acetate or PGMEA is preferred as the ester solvent.

[0158] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0159] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, but examples include ionic and nonionic fluorine-based and / or silicon-based surfactants. Nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is blended, the blending amount is typically 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, based on the total amount of the organic developer.

[0160] The development process can be carried out by a known development method, for example, a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method), etc.

[0161] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method. Examples of the rinse treatment method include a method in which the rinse solution is continuously applied onto a support rotating at a constant speed (spin coating method), a method in which the support is immersed in the rinse solution for a certain period of time (dip method), and a method in which the rinse solution is sprayed onto the surface of the support (spray method). For the rinse treatment, it is preferable to use a rinse solution containing an organic solvent.

[0162] A negative pattern can be formed by the above-described film forming step, exposure step, and development step.

[0163] (Cured Film) The cured film of this embodiment is obtained by curing the negative photosensitive resin composition of the above-described embodiment.

[0164] (Method for Producing Cured Film) The method for producing a cured film of this embodiment includes step (i) of forming a photosensitive resin film on a support using the negative photosensitive resin composition of the embodiment described above, and step (ii) of curing the photosensitive resin film to obtain a cured film. The operation of step (i) can be performed in the same manner as the above-described [Film Formation Step]. The baking treatment can be performed, for example, at a temperature of 60 to 150°C for 40 to 600 seconds. The curing treatment in step (ii) can be performed, for example, at a temperature of 100 to 250°C for 0.5 to 2 hours. The method for producing a cured film of this embodiment may include other steps in addition to steps (i) and (ii). For example, the above-described [Exposure Step] may be included between steps (i) and (ii). In this case, the photosensitive resin film formed in step (i) may be selectively exposed to light, and the photosensitive resin film (pre-cured film) that has been subjected to a post-exposure bake (PEB) treatment as needed may be cured to obtain a cured film. According to the method for producing a cured film of the embodiment described above, a cured film that faithfully reproduces a mask pattern can be easily produced.

[0165] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0166] <Preparation of Negative Photosensitive Resin Compositions> (Examples 1 to 8, Comparative Example 1) Each component shown in Table 1 was dissolved in ethyl lactate, mixed, and filtered using a PTFE filter (pore size 1 μm, manufactured by PALL Corporation) to prepare a negative photosensitive resin composition (solution with a solid content of 65% by mass) for each example.

[0167]

[0168] In Table 1, each abbreviation has the following meaning. The value in brackets [ ] indicates the amount of each component (parts by mass; converted to solids). Component (P): Bisphenol novolac epoxy resin (P)-1: Bisphenol A novolac epoxy resin (trade name "jER-157S70", manufactured by Mitsubishi Chemical Corporation) represented by the following chemical formula (Ap-1). Weight average molecular weight: 2900, molecular weight dispersity: 4.23, epoxy equivalent: 220 g / eq., content of bisphenol epoxy monomer in the bisphenol A novolac epoxy resin: 17% by mass

[0169] (P)-2: Bisphenol A novolac epoxy resin represented by the following chemical formula (Ap-2). This is a purified product obtained by purifying the bisphenol A novolac epoxy resin (trade name "jER-157S70", manufactured by Mitsubishi Chemical Corporation) by the purification method described below. Weight average molecular weight: 4,500, molecular weight dispersity: 2.17, epoxy equivalent: 226 g / eq., and the content of bisphenol epoxy monomer in the bisphenol A novolac epoxy resin: 1.5% by mass.

[0170] [First step of purification method] 300 g (300 parts by mass) of ethanol was added to 100 g (100 parts by mass) of the bisphenol A novolac epoxy resin (trade name "jER-157S70", manufactured by Mitsubishi Chemical Corporation). The mixture was then heated to 70°C to melt the bisphenol A novolac epoxy resin (trade name "jER-157S70", manufactured by Mitsubishi Chemical Corporation) in the ethanol, yielding a mixed solution. The resulting mixed solution was refluxed at 77°C for 1 hour.

[0171] [Second step of purification method] The mixed liquid after refluxing was allowed to stand and cooled to 25° C. As a result, the molten resin in the mixed liquid solidified.

[0172] [Third step of purification method] The solidified material was separated from the remaining mixed liquid (ethanol etc.), and the solidified material was collected.

[0173] Next, the recovered solidified material was subjected to a further three times of the operation of carrying out the above-mentioned steps 1, 2, and 3 in this order. That is, the bisphenol A novolac epoxy resin (trade name "jER-157S70", manufactured by Mitsubishi Chemical Corporation) was subjected to a total of four times of the purification operation of carrying out the above-mentioned steps 1, 2, and 3 in this order.

[0174] The solidified material recovered after the four purification steps was then dried overnight at 100° C. in a vacuum oven to obtain a purified product of bisphenol A novolac epoxy resin.

[0175]

[0176] [Measurement of Weight-Average Molecular Weight] The weight-average molecular weight of the bisphenol A novolac epoxy resin (trade name "jER-157S70", manufactured by Mitsubishi Chemical Corporation) before purification and the purified product after purification were measured by GPC (Gel Permeation Chromatography) under the following conditions: Apparatus: HLC-8320 (manufactured by Tosoh Corporation) Column: TSK Gel Super HM-N (3 columns connected) Eluent: tetrahydrofuran Flow rate: 0.6 mL / min Column temperature: 40°C Detector: RI Polystyrene standard

[0177] GPC charts obtained from the signal from the RI detector are shown in Figures 1 and 2. Figure 1 is a GPC chart for the bisphenol A novolac epoxy resin before purification. Figure 2 is a GPC chart for the bisphenol A novolac epoxy resin after purification. The vertical axis represents the detection intensity (mV), and the horizontal axis represents the retention time (min). Measurement of bisphenol epoxy monomer content: The content of bisphenol epoxy monomer in the bisphenol A novolac epoxy resin was determined as follows. That is, the content of the bisphenol epoxy monomer was calculated as the ratio of the peak area from 14.4 min to 15.3 min in the retention time range to the peak area from 9.5 min to 15.3 min in the GPC chart.

[0178] [Measurement of epoxy equivalent] Preparation of sodium carbonate / acetic acid solution: A sodium carbonate / acetic acid solution was prepared according to the following procedure. First, approximately 10 g of sodium carbonate was placed in a crucible and heated in an electric furnace at 500°C for 1 hour. Next, the heated sodium carbonate was placed in a desiccator and allowed to stand for 1 hour until it reached room temperature. Next, approximately 2.5 to 3.0 g of sodium carbonate was weighed out after standing at room temperature and placed in a 500 mL measuring flask. Next, acetic acid was added until the total volume was 500 mL, and the sodium carbonate was dissolved.

[0179] Calculation of Factor F of Hydrogen Bromide / Acetic Acid Solution: Using a volumetric pipette, 5 mL of the prepared sodium carbonate / acetic acid solution was placed in a disposable cup. Next, approximately 30 mL of toluene was added to the disposable cup. Next, acetic acid was added to the disposable cup until the electrode was submerged. Next, a small amount of crystal violet / acetic acid solution was added as an indicator. The resulting solution was titrated with the hydrogen bromide / acetic acid solution. Next, the Factor F of the hydrogen bromide / acetic acid solution was calculated using the following formula: S represents the mass (g) of sodium carbonate. P represents the purity (%) of sodium carbonate. A represents the amount (mL) of the hydrogen bromide / acetic acid solution added. F = {S x (5 / 500) x (P / 100)} / (0.0053 x A)

[0180] Measurement of oxirane oxygen concentration: Wg of the epoxy resin to be measured was placed in a disposable cup. Next, approximately 30 mL of toluene was added to the disposable cup. Next, acetic acid was added to the cup until the electrode was submerged. Next, a small amount of crystal violet / acetic acid solution was added as an indicator. The resulting solution was titrated with a hydrogen bromide / acetic acid solution. The endpoint was the point at which the solution changed from blue to green and a large potential difference was observed. Next, the oxirane oxygen concentration X (%) was calculated using the following formula: T means the amount (mL) of hydrogen bromide / acetic acid solution added. X = (0.16 x T x F) / W

[0181] Calculation of epoxy equivalent: The epoxy equivalent Y was calculated from the following formula: Y = (16 x 100) / X

[0182] Component (M): Epoxy group-containing compound other than component (P) (M)-1: Epoxy group-containing monomer represented by the following chemical formula (m-1). (M)-2: Epoxy group-containing monomer represented by the following chemical formula (m-2). (M)-3: Epoxy group-containing monomer represented by the following chemical formula (m-3). (M)-4: Epoxy group-containing monomer represented by the following chemical formula (m-4).

[0183]

[0184] Component (I): Cationic polymerization initiator (I)-1: A cationic polymerization initiator represented by the following chemical formula (I-1).

[0185]

[0186] Other examples include silane coupling agents (Add)-1: compounds represented by the following chemical formula (SC-1).

[0187]

[0188] <Evaluation> The following evaluation was carried out as a model test to check whether the negative photosensitive resin composition flows through the holes in the cover layer and falls into the hollow portion during the production of the hollow structure.

[0189] The negative photosensitive resin composition of each example was evaluated for its ability to sink into holes by the following model test. Model test method: A SiO2 substrate with a hole pattern having 60 holes, each 50 μm high and 5 μm in diameter, was used. ２ A substrate having a layer was prepared. Each negative photosensitive resin composition of each example was applied to this substrate using a spin coater, and then heated on a hot plate under the soft bake conditions shown in the table to form a photosensitive resin film (film thickness 20 μm). After heating, the number of holes into which the resin composition had fallen was confirmed by observation with an optical microscope. This evaluation was performed three times for each resin composition, and the average number is shown in the table as "(number of holes into which the resin composition had fallen) / 60."

[0190] The soft bake conditions in the table are as follows: "65°C, 20 min" refers to a 20-minute heat treatment at 65°C. "65°C, 20 min → 120°C, 4 min" refers to a 20-minute heat treatment at 65°C, followed by a 4-minute heat treatment at 120°C. "65°C, 20 min → 150°C, 4 min" refers to a 20-minute heat treatment at 65°C, followed by a 4-minute heat treatment at 150°C. "65°C, 20 min → 180°C, 4 min" refers to a 20-minute heat treatment at 65°C, followed by a 4-minute heat treatment at 180°C.

[0191]

[0192] The results shown in Table 2 confirm that when the negative-tone photosensitive resin compositions of Examples 1 to 8 according to the present invention were used, the resin did not flow through the holes in the cover layer and fall into the hollows, even when the soft bake temperature was increased, and a resin film could be stably formed on the cover layer having holes. On the other hand, when the negative-tone photosensitive resin composition of Comparative Example 1 was used, the resin did not fall into the hollows at a soft bake temperature of 120°C, but when the soft bake temperature was further increased to 150°C and 180°C, the resin fell into the hollows.

[0193] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

[0194] 10 Support, 20 Microelectronic device, 30 First cover layer, 35 Hole, 40 Second cover layer, 50 Hollow portion, 60 Bump, 100 Hollow structure

Claims

1. A negative photosensitive resin composition containing a bisphenol novolac type epoxy resin and a cationic polymerization initiator, wherein the weight average molecular weight of the bisphenol novolac type epoxy resin is 4000 or more.

2. The negative photosensitive resin composition according to claim 1, wherein the content ratio of the bisphenol epoxy monomer in the bisphenol novolac type epoxy resin is 2% by mass or less based on the total mass of the bisphenol novolac type epoxy resin.

3. The negative photosensitive resin composition according to claim 1 or 2, wherein the bisphenol novolac type epoxy resin is a bisphenol A novolac type epoxy resin.

4. Comprising a support, a cover layer formed on the support, and a top plate portion covering the cover layer, wherein a hollow portion is provided between the support and the cover layer, used for forming the top plate portion of a hollow structure in which a hole penetrating from the hollow portion to the top plate portion is formed in the cover layer, the negative photosensitive resin composition according to claim 1 or 2.

5. Comprising a support, a cover layer formed on the support, and a top plate portion covering the cover layer, wherein a hollow portion is provided between the support and the cover layer, a hollow structure in which a hole penetrating from the hollow portion to the top plate portion is formed in the cover layer, wherein the top plate portion is a cured product of the negative photosensitive resin composition according to claim 1 or 2.

6. The step of covering the support with the cover layer; The step of providing a hollow portion between the support and the cover layer; The step of processing a hole pattern in the cover layer to form a hole penetrating the cover layer; The step of applying the negative photosensitive resin composition according to claim 1 or 2 on the cover layer to form a photosensitive resin film on the cover layer; The step of exposing the photosensitive resin film; The step of developing the exposed photosensitive resin film with a developer containing an organic solvent to form a negative pattern; The step of curing the negative pattern to form a top plate portion covering the cover layer, the method for manufacturing the hollow structure according to claim 5.

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

8. A laminated film comprising a support film and a photosensitive resin composition layer laminated on the support film, The laminated film, wherein the photosensitive resin composition layer is composed of the negative photosensitive resin composition according to claim 1 or 2.

9. The laminated film according to claim 8, further comprising a cover film disposed on the side of the photosensitive resin composition layer opposite to the side where the support film is present.

10. A method for manufacturing a laminated film, comprising applying the negative photosensitive resin composition according to claim 1 or 2 on a support film to form a photosensitive resin composition layer laminated on the support film.