Negative photosensitive resin composition and pattern forming method

Abstract

To provide a negative type photosensitive resin composition which prevents undercut in pattern formation, and a pattern formation method.SOLUTION: A negative type photosensitive resin composition contains an epoxy group-containing compound, a photocationic polymerization initiator, and a resin having a constitutional unit represented by general formula (ahs1). The epoxy group-containing compound contains a novolak type epoxy resin. The photocationic polymerization initiator contains an onium borate salt. In the general formula (ahs1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Yax1 is a single bond or a divalent connection group; Wax1 is an aromatic hydrocarbon group that may have a substituent; and nax1 is an integer of 1 or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a negative photosensitive resin composition and a method for forming a pattern. [Background technology]

[0002] In recent years, the development of tiny electronic devices such as surface acoustic wave (SAW) filters has progressed. Packages that encapsulate such electronic devices have a hollow structure to ensure the propagation of surface acoustic waves and the mobility of the movable parts of the electronic devices. The package is formed by preparing a hollow structure in which a hollow space is maintained above a wiring board on which electrodes are formed, using a photosensitive resin composition, and molding the hollow structure. The photosensitive resin composition used here is required to have a thin and strong cured film.

[0003] The photosensitive resin composition is also used as a spacer (wall material) between a semiconductor wafer and a transparent substrate. For example, a negative photosensitive resin composition is used to form a photosensitive resin film on the surface of a semiconductor wafer, and the photosensitive resin film is selectively exposed to radiation such as light or electron beams, and then developed to form a pattern, and then pressed onto a transparent substrate (e.g., a glass substrate) to form a spacer. When the photosensitive resin film is developed by photolithography, it is necessary that a film of a thickness required for a spacer is formed, and that high-resolution patterning is possible with a good shape and no residue.

[0004] In response to these demands, a photosensitive resin composition containing an epoxy resin and a photocationic polymerization initiator has been proposed. For example, Patent Document 1 discloses an example of a negative photosensitive resin composition containing a specific epoxy resin and sulfonium borate as a photocationic polymerization initiator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2018 / 194154 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in conventional negative photosensitive resin compositions such as the negative photosensitive resin composition described in Patent Document 1, when a negative pattern is formed on the surface of a semiconductor wafer, the composition tends to cut into the peripheral portion of the negative pattern image (residual film) that contacts the semiconductor wafer at the interface between the two, which is called an undercut. If this undercut occurs, it may lead to plating defects after the structure is formed.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a negative photosensitive resin composition that is less likely to cause undercut during pattern formation, and a pattern formation method. [Means for solving the problem]

[0008] The present inventors have found through their investigations that the problem of undercuts occurring when a negative pattern is formed using a negative photosensitive resin composition is particularly likely to occur when a photocationic polymerization initiator in which the anion moiety is a borate anion is used. The inventors have also found that the occurrence of undercuts can be suppressed by using a resin having a structural unit containing a phenolic hydroxyl group in combination with the photocationic polymerization initiator, and have completed the present invention.

[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 type photosensitive resin composition comprising an epoxy group-containing compound (A), a photocationic polymerization initiator (I), and a resin having a structural unit represented by the following general formula (ahs1), wherein the epoxy group-containing compound (A) contains a novolac type epoxy resin, and the photocationic polymerization initiator (I) contains an onium borate salt.

[0010] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.

[0011] A second 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. Effect of the Invention

[0012] According to the present invention, it is possible to provide a negative photosensitive resin composition which is less likely to cause undercut during pattern formation, and a method for forming a pattern. [Brief description of the drawings]

[0013] [Figure 1] 1 is a table showing evaluation criteria for undercut in this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0015] (Negative-type photosensitive resin composition) The negative type photosensitive resin composition of this embodiment (hereinafter sometimes simply referred to as "photosensitive composition") contains an epoxy group-containing compound (A) (hereinafter also referred to as "component (A)"), a photocationic polymerization initiator (I) (hereinafter also referred to as "component (I)"), and a resin having a structural unit represented by general formula (ahs1) (hereinafter this resin is also referred to as "component (P)"). When a photosensitive resin film is formed using such a photosensitive composition and selectively exposed to light, in the exposed portion of the photosensitive resin film, the cationic portion of the (I) component is decomposed to generate an acid, and the epoxy group in the (A) component is ring-opened and polymerized by the action of the acid, decreasing the solubility of the (A) component in a developer containing an organic solvent, while in the unexposed portion of the photosensitive resin film, the solubility of the (A) component in a developer containing an organic solvent does not change, so that a difference in solubility in a developer containing an organic solvent occurs between the exposed portion and the unexposed portion of the photosensitive resin film. Therefore, when the photosensitive resin film is developed with a developer containing an organic solvent, the unexposed portion is dissolved and removed, forming a negative pattern.

[0016] <Epoxy group-containing compound (A)> The epoxy group-containing compound (component (A)) may be a compound having a sufficient number of epoxy groups in one molecule to form a negative pattern by exposure. The component (A) used in the photosensitive composition of the present embodiment contains a novolac type epoxy resin (hereinafter also referred to as "component (A1)"). In addition to component (A1), component (A) may contain other epoxy group-containing compounds in combination. However, the component (A) does not include those that fall under the category of silane coupling agents.

[0017] <Novolac type epoxy resin> Suitable examples of the novolac epoxy resin (component (A1)) include epoxy resins represented by the following general formula (anv0).

[0018] [ka] [In the formula, R p1 and R p2 are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. p1 may be the same or different. p2 may be the same or different. n1 is an integer of 1 to 5. R EP is an epoxy group-containing group. EP may be the same or different.

[0019] In the above formula (anv0), R p1 , R p2 The alkyl group having 1 to 5 carbon atoms is, for example, a straight-chain, branched-chain, or cyclic alkyl group having 1 to 5 carbon atoms. Examples of the straight-chain or branched-chain 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. Examples of the cyclic alkyl group include a cyclobutyl group, and a cyclopentyl group. Among them, R p1 , R p2As the alkyl group, a hydrogen atom or a linear or branched alkyl group is preferable, a hydrogen atom or a linear alkyl group is more preferable, and a hydrogen atom or a methyl group is particularly preferable. In the formula (anv0), multiple R p1 may be the same or different. p2 may be the same or different from each other.

[0020] In the above formula (anv0), n1 is an integer of 1 to 5, preferably 2 or 3, and more preferably 2.

[0021] In the above formula (anv0), R EP is an epoxy group-containing group. R EP The epoxy group-containing group is not particularly limited, and examples thereof include a group consisting of only epoxy groups; a group consisting of only alicyclic epoxy groups; and a group having an epoxy group or an alicyclic epoxy group and a divalent linking group. The alicyclic epoxy group is an alicyclic group having an oxacyclopropane structure which is a three-membered ring ether, and specifically, is a group having an alicyclic group and an oxacyclopropane structure. The alicyclic group that is the basic skeleton of the alicyclic epoxy group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic group include a norbornyl group, an isobornyl group, a tricyclononyl group, a tricyclodecyl group, and a tetracyclododecyl group. The hydrogen atom of these alicyclic groups may be substituted with an alkyl group, an alkoxy group, a hydroxyl group, or the like. In the case of a group having an epoxy group or an alicyclic epoxy group and a divalent linking group, it is preferable that the epoxy group or the alicyclic epoxy group is linked via the divalent linking group bonded to an oxygen atom (—O—) in the formula.

[0022] 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.

[0023] Regarding the optionally substituted divalent hydrocarbon group: Such a divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group in the divalent hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0024] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, even more preferably 2 to 4 carbon atoms, and most preferably 2 or 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0025] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is present in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0026] The aromatic hydrocarbon group in the divalent hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having (4n+2) π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0027] The divalent hydrocarbon group may have a substituent. The linear or branched aliphatic hydrocarbon group as the divalent hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0028] The alicyclic hydrocarbon group in the aliphatic hydrocarbon group containing a ring in the structure as the divalent hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are substituted with the halogen atoms. In the alicyclic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom. Preferred examples of the substituent containing a heteroatom include -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0029] In the aromatic hydrocarbon group as a divalent hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the alicyclic hydrocarbon group.

[0030] Regarding divalent linking groups containing heteroatoms: The heteroatom in the divalent linking group containing a heteroatom is an atom other than a carbon atom or a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

[0031] In the divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-; -C(=O)-NH-, -NH-, -NH-C(=O)-O-, -NH-C(=NH)- (H may be substituted by a substituent such as an alkyl group or an acyl group); -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 , -[Y 21 -C(=O)-O] m” -Y 22 -or-Y 21 -OC(=O)-Y 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -NH-, -NH-C(=O)-O-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, acyl, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. Formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -or-Y 21 -OC(=O)-Y 22 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same ones as the "divalent hydrocarbon group which may have a substituent" listed above in the description of the divalent linking group. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22The group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0032] Among them, R EP As the epoxy group-containing group in the formula (I), a glycidyl group is preferred.

[0033] Additionally, the component (A1) also preferably includes a resin having a structural unit represented by the following general formula (anv1):

[0034] [ka] [In the formula, R EP is an epoxy group-containing group. a22 and R a23 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom.]

[0035] In the above formula (anv1), R a22 , R a23 The alkyl group having 1 to 5 carbon atoms is represented by R p1 , R p2 The above alkyl group has 1 to 5 carbon atoms. R a22 , R a23 The halogen atom is preferably a chlorine atom or a bromine atom. In the above formula (anv1), R EP is R in the above formula (anv0). EP and a glycidyl group is preferred.

[0036] Specific examples of the constitutional unit represented by the formula (anv1) are shown below.

[0037] [ka]

[0038] The component (A1) may be a resin consisting only of the structural unit (anv1), or it may be a resin containing the structural unit (anv1) in addition to other structural units. Examples of other structural units include structural units represented by the following general formulas (anv2) to (anv3).

[0039] [ka] [In the formula, R a24 R is a hydrocarbon group which may have a substituent. a25 ~R a26 , R a28 ~R a30 R each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom. a27 represents an epoxy group-containing group or a hydrocarbon group which may have a substituent.

[0040] In the above formula (anv2), R a24 is a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group which may have a substituent include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0041] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0042] R a24 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0043] R a24 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. R a24Specific examples of the aromatic hydrocarbon group in include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0044] In the above formulas (anv2) and (anv3), R a25 ~R a26 , R a28 ~R a30 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom. The alkyl group having 1 to 5 carbon atoms and the halogen atom are each defined as R a22 , R a23 is the same as:

[0045] In the above formula (anv3), R a27 R is an epoxy group-containing group or a hydrocarbon group which may have a substituent. a27 The epoxy group-containing group is R EP Same as R a27 The optionally substituted hydrocarbon group is R a24 is the same as:

[0046] Specific examples of the structural units represented by the above formulas (anv2) to (anv3) are shown below.

[0047] [ka]

[0048] When the component (A1) contains other structural units in addition to the structural unit (anv1), there are no particular limitations on the proportion of each structural unit in the component (A1), but the total amount of structural units having an epoxy group relative to the total amount of all structural units constituting the component (A1) is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, and even more preferably 30 to 70 mol %.

[0049] Commercially available products of the component (A1) include, for example, novolac epoxy resins such as JER-152, JER-154, JER-157S70, and JER-157S65 (all manufactured by Mitsubishi Chemical Corporation), EPICLON N-740, EPICLON N-740, EPICLON N-770, EPICLON N-775, EPICLON N-660, EPICLON N-665, EPICLON N-670, EPICLON N-673, EPICLON N-680, EPICLON N-690, EPICLON N-695, and EPICLON HP5000 (all manufactured by DIC Corporation), and EOCN-1020 (all manufactured by Nippon Kayaku Co., Ltd.).

[0050] As the component (A1), one type may be used alone, or two or more types may be used in combination. In the photosensitive composition of this embodiment, the content of the component (A1) is preferably 10 to 40 parts by mass, more preferably 15 to 35 parts by mass, and even more preferably 20 to 30 parts by mass, relative to 100 parts by mass of the total parts by mass of the component (A).

[0051] <Other epoxy group-containing compounds> As the epoxy group-containing compound other than the component (A1), for example, a resin having a glycidyl ether group in its structure can be used. Examples of epoxy group-containing compounds other than the component (A1) include bisphenol type epoxy resins, aliphatic epoxy resins, and acrylic resins.

[0052] Bisphenol-based epoxy resins: The bisphenol-type epoxy resin (hereinafter also referred to as "component (A2)") may be any resin having a structural unit containing a bisphenol skeleton, and among these, solid bisphenol-type epoxy resins are preferred. The solid bisphenol-type epoxy resin refers to a resin that is solid at 25°C and has a structural unit that includes a bisphenol skeleton. The epoxy equivalent in the component (A2) is, for example, preferably 800 g / eq. or more, more preferably 800 to 1200 g / eq., and even more preferably 900 to 1100 g / eq.

[0053] Suitable examples of the component (A2) include epoxy resins represented by the following general formula (abp1):

[0054] [ka] [In the formula, R EP is an epoxy group-containing group. EP may be the same or different. a31 and R a32 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. 31 is an integer from 1 to 50.

[0055] In the above formula (abp1), R EP is R in the above formula (anv0). EP and a glycidyl group is preferred. In the above formula (abp1), R a31 , R a32 The alkyl group having 1 to 5 carbon atoms is R p1 , R p2 The alkyl groups having 1 to 5 carbon atoms are the same as those in R a31 , R a32 Each of them is preferably a hydrogen atom or a methyl group. R a31 , R a32 The fluorinated alkyl group having 1 to 5 carbon atoms in the formula (I) is the same as the formula (I) above.a31 , R a32 In the above formula, some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with fluorine atoms. In the above formula (abp1), na 31 is an integer from 1 to 50, preferably an integer from 4 to 15, and more preferably an integer from 5 to 8.

[0056] Examples of commercially available products that can be used as the component (A2) include JER-4005, JER-4007, and JER-4010 (all manufactured by Mitsubishi Chemical Corporation); JER-827, JER-828, JER-834, JER-1001, JER-1002, JER-1003, JER-1055, JER-1007, JER-1009, and JER-1010 (all manufactured by Mitsubishi Chemical Corporation); and EPICLON 860, EPICLON 1050, EPICLON 1051, and EPICLON 1055 (all manufactured by DIC Corporation).

[0057] As the component (A2), one type may be used alone, or two or more types may be used in combination. In the photosensitive composition of this embodiment, the content of the component (A2) is preferably 60 to 90 parts by mass, more preferably 65 to 85 parts by mass, and even more preferably 70 to 80 parts by mass, relative to 100 parts by mass of the total parts by mass of the component (A).

[0058] When the (A1) component and the (A2) component are used in combination, the ratio of the (A1) component to the (A2) component, expressed as the mass ratio of the (A1) component / the (A2) component, is preferably 1 / 9 or more and 5 / 5 or less, more preferably 1 / 9 or more and less than 5 / 5, even more preferably 2 / 8 or more and 4 / 6 or less, and particularly preferably 2 / 8 or more and 3 / 7 or less. If the mass ratio is within the above-mentioned preferred range, the resolution is further improved and the adhesion to the substrate is also excellent.

[0059] About Aliphatic Epoxy Resins: Suitable examples of the aliphatic epoxy resin include a compound represented by the following general formula (ta1) (hereinafter, this compound will also be referred to as "component (A3)"): By using the component (A3) in combination, undercutting is less likely to occur during pattern formation.

[0060] [ka] [In the formula, R EP is an epoxy group-containing group. EP may be the same or different.

[0061] In the above formula (ta1), R EP is an epoxy group-containing group, and R in the formula (anv0) EP is the same as:

[0062] Examples of commercially available products that can be used as the component (A3) 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.).

[0063] As the component (A3), one type may be used alone, or two or more types may be used in combination. In the photosensitive composition of this embodiment, the content of the component (A3) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 3.5 parts by mass, relative to 100 parts by mass of the total parts by mass of the component (A). When the content of component (A3) is equal to or greater than the lower limit of the preferred range, undercutting is less likely to occur during pattern formation. On the other hand, when the content of component (A3) is high, sensitivity during pattern formation tends to decrease, whereas when the content is equal to or less than the upper limit of the preferred range, good sensitivity is likely to be maintained.

[0064] Further, examples of the aliphatic epoxy resin include compounds containing a partial structure represented by the following general formula (m1) (hereinafter also referred to as "component (m1)").

[0065] [ka] [In the formula, n2 is an integer of 1 to 4. * indicates a bond.]

[0066] In the above formula (m1), n2 is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2.

[0067] The component (m1) may be a compound in which a plurality of partial structures represented by the above general formula (m1) are bonded via a divalent linking group or a single bond. Among these, a compound in which a plurality of partial structures represented by the above general formula (m1) are bonded via a divalent linking group is preferred. The divalent linking group here is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Here, the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom are R in the above formula (anv0). EP The divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom are the same as those described in (epoxy group-containing group), and among these, the divalent linking group containing a hetero atom is preferred. 21 A group represented by -C(=O)-O-, -C(=O)-OY 21 A group represented by Y - is more preferred. 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable.

[0068] Commercially available products that can be used as aliphatic epoxy resins 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); DENACOL EX-211L, EX-212L, EX-214L, EX-216L, EX-321L, and EX-850L (all manufactured by Nagase ChemteX Corporation).

[0069] About Acrylic Resins: Examples of the acrylic resin include resins having epoxy group-containing units represented by the following general formulas (a1-1) and (a1-2).

[0070] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 41 is a divalent hydrocarbon group which may have a substituent. 41 is an integer between 0 and 2. a41 and R a42 are epoxy group-containing groups. 42 is 0 or 1. 41 is (na 43 +1)valent aliphatic hydrocarbon group. 43 is an integer between 1 and 3.

[0071] In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms for R is preferably linear or branched. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms in R is a group in which some or all of the hydrogen atoms in the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

[0072] In the formula (a1-1), Va 41 is a divalent hydrocarbon group which may have a substituent, and R in the formula (anv0) EP Examples of the divalent hydrocarbon group which may have a substituent include the same groups as those explained in the above. Among the above, Va 41 The hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably a linear or branched aliphatic hydrocarbon group, further preferably a linear aliphatic hydrocarbon group, and particularly preferably a linear alkylene group.

[0073] In the formula (a1-1), na 41 is an integer of 0 to 2, and preferably 0 or 1.

[0074] In the above formulas (a1-1) and (a1-2), R a41 , R a42 is an epoxy group-containing group, and R in the formula (anv0) EP is the same as:

[0075] In the formula (a1-2), Wa 41 In (na 43 The aliphatic hydrocarbon group having a valence of +1 means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group in which a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure are combined.

[0076] In the formula (a1-2), na 43 is an integer of 1 to 3, preferably 1 or 2.

[0077] Specific examples of the structural units represented by the above formula (a1-1) or (a1-2) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. R a51 R represents a divalent hydrocarbon group having 1 to 8 carbon atoms. a52 R represents a divalent hydrocarbon group having 1 to 20 carbon atoms. a53 represents a hydrogen atom or a methyl group. 51 is an integer between 0 and 10. R a51 , R a52 , R a53 may be the same or different.

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] Furthermore, the acrylic resin may contain structural units derived from other polymerizable compounds for the purpose of appropriately controlling the physical and chemical properties. Examples of such polymerizable compounds include known radical polymerizable compounds and anion polymerizable compounds. Examples of such polymerizable compounds include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; methacrylic acid derivatives having a carboxyl group and an ester bond such as 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl phthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid; (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate; (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; meth ... Examples of suitable polymerizable compounds include (meth)acrylic acid aryl esters such as phenyl (meth)acrylate and benzyl (meth)acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; vinyl group-containing aromatic compounds such as styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α-methylhydroxystyrene, and α-ethylhydroxystyrene; vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; and amide bond-containing polymerizable compounds such as acrylamide and methacrylamide.

[0083] When the acrylic resin has other structural units, the content of the epoxy group-containing units in the resin is preferably 5 to 40 mol %, more preferably 10 to 30 mol %, and even more preferably 15 to 25 mol %.

[0084] In addition, as the epoxy group-containing compound other than the component (A1), in addition to the above-mentioned resins, a compound represented by the following chemical formula (A3-1) and a compound represented by the following chemical formula (A3-2) may be used. An example of a commercially available product that can be used as the compound represented by the following chemical formula (A3-1) is TECHMORE VG-3101L (manufactured by Printec Co., Ltd.). Examples of commercially available products that can be used as the compound represented by the following chemical formula (A3-2) include Showfree (registered trademark) BATG (manufactured by Showa Denko KK).

[0085] [ka]

[0086] Further, examples of epoxy group-containing compounds other than the component (A1) include trimethylolpropane triglycidyl ether, glycerin triglycidyl ether; pentaerythritol tetraglycidyl ether, ditrimethylolpropane tetraglycidyl ether, diglycerin tetraglycidyl ether, erythritol tetraglycidyl ether; xylitol pentaglycidyl ether, dipentaerythritol pentaglycidyl ether, inositol pentaglycidyl ether; dipentaerythritol hexaglycidyl ether, sorbitol hexaglycidyl ether, inositol hexaglycidyl ether, and the like.

[0087] In the photosensitive composition of the present embodiment, the component (A) contains the component (A1). The component (A) is preferably one containing the component (A1) and the component (A2), and among these, one containing the component (A1) and a solid bisphenol type epoxy resin is more preferable, and one containing an epoxy resin represented by the general formula (anv0) and an epoxy resin represented by the general formula (abp1) is even more preferable. Moreover, the component (A) is particularly preferably one containing the components (A1), (A2) and (A3).

[0088] The polystyrene-equivalent weight average molecular weight of the component (A) is preferably 100 to 300000, more preferably 200 to 200000, and even more preferably 300 to 200000. By setting the weight average molecular weight within this range, peeling from the support is less likely to occur, and the strength of the cured film that is formed is sufficiently increased.

[0089] The content of the component (A) in the photosensitive composition of the embodiment may be adjusted according to the film thickness of the photosensitive resin film to be formed, etc.

[0090] <Photocationic Polymerization Initiator (I)> A photocationic polymerization initiator (component (I)) 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. The component (I) used in the photosensitive composition of this embodiment contains an onium borate salt (hereinafter also referred to as "component (I1)"). In addition to the component (I1), the component (I) may also contain a cationic photopolymerization initiator other than the component (I1).

[0091] As described above, when a negative pattern is formed using a negative photosensitive resin composition, there is a specific problem that undercut is likely to occur when a photocationic polymerization initiator having a borate anion moiety is used. The photosensitive composition of the present embodiment containing an onium borate salt is useful for solving such a problem.

[0092] Onium borate salts Onium borate salts (component (I1)) generate a relatively strong acid upon exposure to light. Therefore, by forming a pattern using a photosensitive composition containing component (I1), sufficient sensitivity is obtained and a good pattern is formed. In addition, the use of component (I1) is less likely to cause toxicity or metal corrosion. Suitable examples of the component (I1) include compounds represented by the following general formula (I1).

[0093] [ka] [In the formula, R b01 ~R b04 are each independently an aryl group which may have a substituent, or a fluorine atom; q is an integer of 1 or more; q+ is a q-valent organic cation.

[0094] Anion section In the formula (I1), R b01 ~R b04 The aryl group in the formula (I) preferably has 5 to 30 carbon atoms, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples include a naphthyl group, a phenyl group, and an anthracenyl group, and the phenyl group is preferred because of its easy availability. R b01 ~R b04 The aryl group in may have a substituent. The substituent is not particularly limited, but is preferably a halogen atom, a hydroxyl group, an alkyl group (preferably a linear or branched alkyl group, preferably having 1 to 5 carbon atoms), or a halogenated alkyl group, more preferably a halogen atom or a halogenated alkyl group having 1 to 5 carbon atoms, and particularly preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. When the aryl group has a fluorine atom, the polarity of the anion moiety is increased, which is preferable. Among them, R in formula (I1) b01 ~R b04 As each of these, a fluorinated phenyl group is preferable, and a perfluorophenyl group is particularly preferable.

[0095] A preferred example of the anion portion of the compound represented by formula (I1) is tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - );Tetrakis[(trifluoromethyl)phenyl]borate ([B(C6H4CF3)4] - );Difluorobis(pentafluorophenyl)borate ([(C6F5)2BF2] -);Trifluoro(pentafluorophenyl)borate ([(C6F5)BF3] - );Tetrakis(difluorophenyl)borate ([B(C6H3F2)4] - ) etc. Among them, tetrakis(pentafluorophenyl)borate ([B(C6F5)4] - ) is particularly preferred.

[0096] ·Cation part In the formula (I1), Q q+ Suitable examples of the cation include a sulfonium cation and an iodonium cation, and the organic cations represented by the following general formulas (ca-1) to (ca-5) are particularly preferred.

[0097] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 R each independently represents an aryl group, a heteroaryl group, an alkyl group or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 represents -C(=O)- or -C(=O)-O-. 201 each independently represents an arylene group, an alkylene group, or an alkenylene group; x is 1 or 2. W 201 represents a (x+1)-valent linking group.

[0098] R 201 ~R 207 , and R 211 ~R 212 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 , and R 211 ~R 212 The heteroaryl group in the above formula (I) may be one in which a part of the carbon atoms constituting the aryl group is replaced with a heteroatom. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroaryl group include a group in which one hydrogen atom has been removed from 9H-thioxanthene; examples of the substituted heteroaryl group include a group in which one hydrogen atom has been removed from 9H-thioxanthen-9-one. R 201 ~R 207 , and R 211 ~R 212 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 , and R 211 ~R 212 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 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 (ca-r-1) to (ca-r-10).

[0099] [ka] [In the formula, R' 201 each independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0100] In the above formulas (ca-r-1) to (ca-r-10), R' 201 each independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0101] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or a cyclic aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0102] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201 Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group in the above include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms, or rings in which some of the hydrogen atoms constituting these aromatic rings or aromatic heterocycles are substituted with oxo groups, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, etc. R' 201Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, anthracenyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), a group in which one hydrogen atom has been removed from a ring in which some of the hydrogen atoms constituting the aromatic ring have been substituted with an oxo group or the like (for example, anthraquinone, etc.), and a group in which one hydrogen atom has been removed from an aromatic heterocycle (for example, 9H-thioxanthene, 9H-thioxanthen-9-one, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0103] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0104] Among them, R' 201 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0105] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0106] Optionally substituted chain alkyl groups: R' 201 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group, and a docosyl group. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0107] An optionally substituted chain alkenyl group: R' 201 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0108] R' 201 Examples of the substituent in the cyclic group, chain alkyl group or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, an oxo group, the above-mentioned R' 201 In the above formula, examples include a cyclic group, an alkylcarbonyl group, and a thienylcarbonyl group.

[0109] Among them, R' 201 is preferably a cyclic group which may have a substituent, or a chain alkyl group which may have a substituent.

[0110] R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they do not include a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R Nis an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, in which a ring containing a sulfur atom in the ring skeleton in the formula is a 3- to 10-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0111] In the above formula (ca-3), R 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups they may be bonded to each other to form a ring.

[0112] In the above formula (ca-3), R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms.

[0113] In the above formula (ca-4) and formula (ca-5), Y 201 each independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in R' 201Examples of the aromatic hydrocarbon group in the above formula include groups in which one hydrogen atom has been removed from the aryl groups exemplified above. Y 201 The alkylene group and alkenylene group in R' 201 Examples of the chain alkyl group and the chain alkenyl group in the above formula (I) include groups in which one hydrogen atom has been removed from the groups exemplified as the chain alkyl group and the chain alkenyl group in the above formula (I).

[0114] In the above formulas (ca-4) and (ca-5), x is 1 or 2. W 201 is a (x+1)-valent linking group, that is, a divalent or trivalent linking group. W 201 The divalent linking group in the formula (A1) is preferably a divalent hydrocarbon group which may have a substituent. EP The divalent hydrocarbon groups which may have a substituent are preferably the same as those exemplified by W. 201 The divalent linking group in may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group, or a group consisting of an arylene group alone is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and the phenylene group is particularly preferred. W 201 The trivalent linking group in 201 and a group in which one hydrogen atom has been removed from the divalent linking group represented by the formula: W 201 As the trivalent linking group in the formula (I), a group in which two carbonyl groups are bonded to an arylene group is preferable.

[0115] 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).

[0116] [ka]

[0117] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent. The substituent may be any of the above-mentioned R 201 ~R 207 and R 210 ~R 212 The substituents are the same as those exemplified as the substituents that may be possessed by the

[0118] As the cation represented by the formula (ca-1), the cations represented by the following general formulas (ca-1-25) to (ca-1-35) are also preferable.

[0119] [ka]

[0120] [ka] [In the formula, R' 211 is an alkyl group. hal is a hydrogen atom or a halogen atom.

[0121] As the cation represented by the formula (ca-1), the cations represented by the following chemical formulas (ca-1-36) to (ca-1-48) are also preferable.

[0122] [ka]

[0123] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0124] 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).

[0125] [ka]

[0126] 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).

[0127] [ka]

[0128] As the cation represented by the formula (ca-5), the cations represented by the following general formulas (ca-5-1) to (ca-5-3) are also preferable.

[0129] [ka] [In the formula, R' 212 R' is an alkyl group or a hydrogen atom. 211 is an alkyl group.

[0130] Among the above, the cationic part [(Q q+ ) 1 / q ] is preferably a cation represented by general formula (ca-1), more preferably a cation represented by each of formulas (ca-1-1) to (ca-1-48), and even more preferably a cation represented by formula (ca-1-25), formula (ca-1-29), formula (ca-1-35), formula (ca-1-47), or formula (ca-1-48).

[0131] Specific examples of suitable components (I1) are given below.

[0132] [ka]

[0133] As the component (I1), one type may be used alone, or two or more types may be used in combination. In the photosensitive composition of this embodiment, the content of the component (I1) is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, and even more preferably 0.5 to 1 part by mass, relative to 100 parts by mass of the total parts by mass of the component (A). When the content of the (I1) component is equal to or greater than the lower limit of the above-mentioned preferred range, sufficient sensitivity is obtained, and the lithography properties of the pattern are further improved. In addition, the strength of the cured film is further increased. On the other hand, when the content is equal to or less than the upper limit of the above-mentioned preferred range, the sensitivity is appropriately controlled, and a pattern with a good shape is easily obtained.

[0134] <Other cationic photopolymerization initiators> Examples of photocationic polymerization initiators other than the above-mentioned component (I1) include a compound represented by the following general formula (I2) (hereinafter referred to as "component (I2)") and a compound represented by the following general formula (I3-1) or (I3-2) (hereinafter referred to as "component (I3)").

[0135] Regarding the compound represented by general formula (I2) (component (I2)): The component (I2) is a compound represented by the following general formula (I2). The component (I2) generates a relatively strong acid upon exposure to light, so that when a photosensitive composition containing the component (I) is used to form a pattern, sufficient sensitivity is obtained and a good pattern is formed.

[0136] [ka] [In the formula, R b05 is a fluorine atom or a fluorine-containing alkyl group which may have a substituent. b05 may be the same or different. q is an integer of 1 or more, and Q q+ is a q-valent organic cation.

[0137] Anion section In the formula (I2), Rb05 is a fluorine atom or a fluorine-containing alkyl group which may have a substituent. b05 may be the same or different from each other. R b05 The fluorinated alkyl group in the above formula preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and even more preferably 1 to 5. Specific examples include alkyl groups having 1 to 5 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms. Among them, R b05 is preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and further preferably a fluorine atom, a trifluoromethyl group or a pentafluoroethyl group.

[0138] The anion portion of the compound represented by formula (I2) is preferably represented by the following general formula (b0-2a).

[0139] [ka] [In the formula, R bf05 is a fluorinated alkyl group which may have a substituent. 1 is an integer from 1 to 5.

[0140] In formula (b0-2a), R bf05 The optionally substituted fluorinated alkyl group in R b05 The substituents are the same as the optionally substituted fluorinated alkyl groups listed under 1. In formula (b0-2a), nb 1 is preferably an integer of 1 to 4, more preferably an integer of 2 to 4, and most preferably 3.

[0141] ·Cation part In formula (I2), q is an integer of 1 or more, q+ is a q-valent organic cation. This Q q+ As the above, Q in the formula (I1) q+Among these, cations represented by general formula (ca-1) are preferred, with cations represented by formulas (ca-1-1) to (ca-1-48) being more preferred, and cations represented by formula (ca-1-25), (ca-1-29), (ca-1-35), and (ca-1-47) being even more preferred.

[0142] Specific examples of suitable components (I2) are given below.

[0143] [ka]

[0144] Regarding the compound represented by general formula (I3-1) or (I3-2) (component (I3)): The component (I3) is a compound represented by the following general formula (I3-1) or (I3-2).

[0145] [ka] [In the formula, R b11 ~R b12 is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom. m is an integer of 1 or more, and M m+ are each independently an organic cation having a valence of m.

[0146] {Component (I3-1)} Anion section In formula (I3-1), R b12 is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom, and R' 201Among the cyclic groups, chain alkyl groups, and chain alkenyl groups in the explanation of the above, those having no substituent or those having a substituent other than a halogen atom are exemplified. R b12 is preferably a chain alkyl group which may have a substituent other than a halogen atom, or an aliphatic cyclic group which may have a substituent other than a halogen atom. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10. The aliphatic cyclic group is preferably a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like (which may have a substituent other than a halogen atom); R b12 The hydrocarbon group may have a substituent other than a halogen atom, and examples of the substituent include R b11 Examples of the substituents include those similar to the substituents other than halogen atoms that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above formula. The phrase "may have a substituent other than a halogen atom" as used herein not only excludes the case where a substituent consists of only halogen atoms, but also excludes the case where a substituent contains at least one halogen atom (for example, the case where the substituent is a fluorinated alkyl group, etc.).

[0147] Preferred specific examples of the anion portion of the component (I3-1) are shown below.

[0148] [ka]

[0149] ·Cation part In formula (I3-1), M m+ is an m-valent organic cation. M m+Suitable examples of the organic cation include the cations represented by the above general formulas (ca-1) to (ca-5), and among these, the cation represented by the above general formula (ca-1) is more preferred. 201 , R 202 , R 203 A sulfonium cation in which at least one of the above is an organic group having 16 or more carbon atoms (aryl group, heteroaryl group, alkyl group, or alkenyl group) which may have a substituent is particularly preferred because it improves the resolution and roughness characteristics. The substituents that the organic group may have are the same as those described above, and include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an oxo group (=O), an aryl group, and groups represented by the above formulas (ca-r-1) to (ca-r-10). The number of carbon atoms in the organic group (aryl group, heteroaryl group, alkyl group, or alkenyl group) is preferably 16 to 25, more preferably 16 to 20, and particularly preferably 16 to 18. m+ Suitable examples of the organic cation include the cations represented by the above formulas (ca-1-25), (ca-1-26), (ca-1-28) to (ca-1-36), (ca-1-38), (ca-1-46), and (ca-1-47). Among these, the cation represented by the above formula (ca-1-29) is particularly preferred.

[0150] {Component (I3-2)} Anion section In formula (I3-2), R b11 is a cyclic group which may have a substituent other than a halogen atom, a chain alkyl group which may have a substituent other than a halogen atom, or a chain alkenyl group which may have a substituent other than a halogen atom, and R' 201 Among the cyclic groups, chain alkyl groups, and chain alkenyl groups in the explanation of the above, those having no substituent or those having a substituent other than a halogen atom are exemplified.

[0151] Among these, R b11 As the substituent, an aromatic hydrocarbon group which may have a substituent other than a halogen atom, an aliphatic cyclic group which may have a substituent other than a halogen atom, or a chain alkyl group which may have a substituent other than a halogen atom are preferable. The substituent which these groups may have includes a hydroxyl group, an oxo group, an alkyl group, an aryl group, a lactone-containing cyclic group, an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be connected via an alkylene group, 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 b11 The bond to V' in the following general formulas (y-al-1) to (y-al-7) is 101 It is.

[0152] [ka] [In the formula, V' 101 V' is a single bond or an alkylene group having 1 to 5 carbon atoms. 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

[0153] 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.

[0154] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 A part of the methylene groups in the alkylene group in the formula (I) may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by R' 201 A divalent group in which one hydrogen atom has been further removed from a cyclic aliphatic hydrocarbon group (a monocyclic alicyclic hydrocarbon group, a polycyclic alicyclic hydrocarbon group) such as those mentioned above is preferred, and a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferred.

[0155] The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group. The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms. Specific examples of the chain alkyl group include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0156] R b11 is preferably a cyclic group which may have a substituent other than a halogen atom. Preferred specific examples of the anion moiety of the component (I3-2) are shown below.

[0157] [ka]

[0158] ·Cation part In formula (I3-2), M m+ is an m-valent organic cation, and M in the formula (I3-1) m+ is the same as:

[0159] In addition, the component (I) is preferably a cationic polymerization initiator that generates an acid having a pKa (acid dissociation constant) of -5 or less upon exposure, from the viewpoints of increasing the elasticity of the resin film and facilitating the formation of a fine structure without leaving any residue. By using a cationic polymerization initiator that generates an acid having a pKa of -6 or less, more preferably a pKa of -8 or less, it is possible to obtain high sensitivity to exposure. The lower limit of the pKa of the acid generated by the component (I) is preferably -15 or more. By using a cationic polymerization initiator that generates an acid having such a suitable pKa, it is easy to achieve high sensitivity. Here, "pKa (acid dissociation constant)" refers to a commonly used index indicating the acid strength of a target substance. In this specification, pKa is a value at a temperature condition of 25°C. The pKa value can be determined by measurement using a known method. Alternatively, a calculated value using known software such as "ACD / Labs" (product name, manufactured by Advanced Chemistry Development) can be used.

[0160] Specific examples of suitable components (I3) are given below.

[0161] [ka]

[0162] In the photosensitive composition of this embodiment, the component (I) contains the component (I1). Suitable examples of the component (I) include those consisting of the component (I1) alone, and those containing the component (I1) and the component (I3).

[0163] In the photosensitive composition of this embodiment, the total content of the component (I) is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass, and even more preferably 0.5 to 1 part by mass, relative to 100 parts by mass of the total parts by mass of the component (A). When the content of the component (I) is equal to or greater than 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 film is further increased. On the other hand, when the content is equal to or less than the upper limit of the preferred range, the sensitivity is appropriately controlled, and a pattern with a good shape is easily obtained.

[0164] <Resin Having a Structural Unit Represented by General Formula (ahs1)> In the photosensitive composition of this embodiment, the component (P) is a resin having a structural unit represented by general formula (ahs1) (hereinafter also referred to as "structural unit (u1)"). By containing the component (P), undercutting is less likely to occur during pattern formation.

[0165] Regarding the constituent unit (u1): The structural unit (u1) is a structural unit represented by general formula (ahs1) below.

[0166] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.]

[0167] In the above formula (ahs1), the alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

[0168] In the above formula (ahs1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0169] Optionally substituted divalent hydrocarbon group: Ya x1 When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0170] Ya x1 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0171] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably contains 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. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0172] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0173] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0174] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and further preferably a methoxy group or an ethoxy group. The halogen atom as the substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0175] Ya x1 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1 carbon atom.

[0176] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. 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 cyclic aliphatic hydrocarbon group.

[0177] Divalent linking groups containing heteroatoms: Ya x1 is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -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-, and the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, acyl, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22 Each of Ya is independently a divalent hydrocarbon group which may have a substituent. x1 Examples of the divalent linking group in the above formula (divalent hydrocarbon group which may have a substituent) include those mentioned above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0178] Among the above, Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-].

[0179] In the above formula (ahs1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ax1 4n+1) hydrogen atoms are removed. The aromatic ring here 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 aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be an aromatic compound having an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1As the aryl group, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene is more preferable. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0180] Wa x1 The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group as the substituent include Ya x1 The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1 The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0181] In the above formula (ahs1), n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0182] Specific examples of the structural unit (u1) represented by the above formula (ahs1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0183] [ka]

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] The structural unit (u1) contained in the component (P) may be of one type, or two or more types. The component (P) may have a structural unit other than the structural unit (u1) represented by general formula (ahs1).

[0188] The component (P) may be a polymer consisting of one or more kinds of repeating units (u1), or a copolymer consisting of repeating units of the structural unit (u1) and other structural units. Among these, the component (P) is more preferably a polymer consisting of one or more kinds of repeating units (u1), and even more preferably a homopolymer consisting of one kind of repeating unit (u1).

[0189] When the component (P) is a copolymer consisting of a repeating structure of the structural unit (u1) and other structural units, the proportion of the structural unit (u1) in the component (P) is preferably 50 mol % or more, more preferably 50 to 95 mol %, and even more preferably 60 to 90 mol %, relative to the total (100 mol %) of all structural units constituting the component (P). By ensuring that the proportion of the structural unit (u1) is at least as large as the lower limit of the aforementioned preferred range, the effect of reducing the occurrence of undercuts during pattern formation can be more easily achieved.

[0190] As the component (P), one type may be used alone, or two or more types may be used in combination. In the photosensitive composition of this embodiment, the content of the component (P) is preferably 1 to 20 parts by mass, more preferably 3 to 15 parts by mass, and even more preferably 5 to 12 parts by mass, relative to 100 parts by mass of the total parts by mass of the component (A). In addition, in the photosensitive composition of this embodiment, the content of the component (P) is preferably 0.5 to 10 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 10 parts by mass, relative to 100 parts by mass of the total of the components (A) and (P). When the content of component (P) is equal to or greater than the lower limit of the preferred range, the effect of preventing undercutting during pattern formation is more easily achieved, whereas when the content is equal to or less than the upper limit of the preferred range, solubility in the developer is maintained, making it easier to obtain a pattern with a good shape.

[0191] <Other ingredients> The photosensitive composition of the present embodiment may contain other components as necessary in addition to the above-mentioned components (A), (I) and (P). If desired, the photosensitive composition of the embodiment may appropriately contain miscible additives, such as a metal oxide (M), a silane coupling agent, a sensitizer component, a solvent, an additional resin for improving the performance of the film, a dissolution inhibitor, a basic compound, a plasticizer, a stabilizer, a colorant, and an antihalation agent.

[0192] Metal oxides (M) In addition to the components (A), (I) and (P), the photosensitive composition of the present embodiment may further contain a metal oxide (M) (hereinafter also referred to as "component (M)"), since this makes it easier to obtain a cured film with increased strength. Furthermore, by including component (M), a pattern with a good shape and high resolution can be formed. Examples of the component (M) include oxides of metals such as silicon (metallic silicon), titanium, zirconium, hafnium, etc. Among these, oxides of silicon are preferred, and among these, it is particularly preferred to use silica.

[0193] In addition, the component (M) is preferably in the form of particles. Such particulate (M) component is preferably a particle group having a volume average particle diameter of 5 to 40 nm, more preferably a particle group having a volume average particle diameter of 5 to 30 nm, and even more preferably a particle group having a volume average particle diameter of 10 to 20 nm. When the volume average particle size of the (M) component is equal to or greater than the lower limit of the preferred range, the strength of the cured film is easily increased. On the other hand, when the volume average particle size is equal to or less than the upper limit of the preferred range, residues are less likely to be generated during pattern formation, and a pattern with higher resolution is easily formed. In addition, the transparency of the resin film is improved. The particle size of the (M) component may be appropriately selected depending on the exposure light source. In general, it is considered that the effect of light scattering is hardly considered for particles having a particle size of 1 / 10 or less of the wavelength of light. For this reason, for example, when forming a fine structure by photolithography using i-line (365 nm), it is preferable to use a particle group (particularly preferably a silica particle group) having a primary particle size (volume average value) of 10 to 20 nm as the (M) component.

[0194] As the component (M), one type may be used alone, or two or more types may be used in combination. When the component (M) is contained, the content thereof is preferably from 5 to 50 parts by mass, and more preferably from 10 to 40 parts by mass, per 100 parts by mass of the component (A). When the content of component (M) is at least the lower limit of the preferred range, the strength of the cured film is further increased, whereas when the content is at most the upper limit of the preferred range, the transparency of the resin film is further increased.

[0195] <Silane coupling agent> The photosensitive composition of the present embodiment may further contain an adhesion promoter to improve adhesion to a substrate, and a silane coupling agent is preferred as the adhesion promoter. Examples of the silane coupling agent include silane coupling agents having reactive substituents such as a carboxy group, a methacryloyl group, an isocyanate group, an epoxy group, etc. Specific examples include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. The silane coupling agents may be used alone or in combination of two or more kinds. When a silane coupling agent is included, the content thereof is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass, per 100 parts by mass of the component (A). When the content of the silane coupling agent is within the above-mentioned preferred range, the strength of the cured film is further increased, and in addition, the adhesion between the cured film and the substrate is further increased.

[0196] Sensitizer component The photosensitive composition of the present embodiment may further contain a sensitizer component. The sensitizer component is not particularly limited as long as it can absorb energy due to exposure and transmit the energy to another substance. Specific examples of the sensitizer component that can be used include benzophenone-based photosensitizers such as benzophenone and p,p'-tetramethyldiaminobenzophenone, carbazole-based photosensitizers, acetophene-based photosensitizers, naphthalene-based photosensitizers such as 1,5-dihydroxynaphthalene, phenol-based photosensitizers, anthracene-based photosensitizers such as 9-ethoxyanthracene, and known photosensitizers such as biacetyl, eosin, rose bengal, pyrene, phenothiazine, and anthrone. The sensitizer component may be used alone or in combination of two or more kinds. When a sensitizer component is included, the content thereof is preferably from 0.1 to 15 parts by mass, more preferably from 0.3 to 10 parts by mass, and even more preferably from 0.5 to 5 parts by mass, per 100 parts by mass of the component (A). When the content of the sensitizer component is within the above-mentioned preferred range, the sensitivity and resolution can be further improved.

[0197] <Solvent> The photosensitive composition of the present embodiment may further contain a solvent (hereinafter sometimes referred to as "component (S)"). Examples of the (S) component include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; monoalkyl ethers or monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether of the above polyhydric alcohols or the above compounds having an ester bond; derivatives of polyhydric alcohols such as compounds having an ether bond, such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred among these; cyclic ethers such as dioxane; esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene; and dimethyl sulfoxide (DMSO).

[0198] The component (S) may be used alone or as a mixed solvent of two or more kinds.

[0199] When the component (S) is contained, its amount is not particularly limited, and is appropriately set according to the thickness of the coating film at a concentration that allows the photosensitive composition to be applied to a substrate or the like without dripping. For example, the (S) component can be used so that the solids concentration is 50% by mass or more, and the (S) component can be used so that the solids concentration is 60% by mass or more. Also, an embodiment that does not substantially contain the component (S) (that is, an embodiment in which the solids concentration is 100% by mass) can be adopted.

[0200] The above-mentioned "additional resin for improving the performance of the membrane" includes a compound represented by the following chemical formula (Add-1), etc. An example of a commercially available product that can be used as the compound represented by the following chemical formula (Add-1) is TrisP-PA (manufactured by Honshu Chemical Industry Co., Ltd.).

[0201] [ka]

[0202] The negative photosensitive resin composition of the present embodiment described above contains an epoxy group-containing compound (A) containing a novolac epoxy resin, a photocationic polymerization initiator (I) containing an onium borate salt, and a resin having a structural unit represented by general formula (ahs1). Conventionally, negative photosensitive resin compositions containing a novolac epoxy resin and a photocationic polymerization initiator have excellent resolution and mechanical properties, but when a sulfonium borate salt is used as the photocationic polymerization initiator, undercuts may occur between the cured resist film at the opening of the hollow structure and the substrate. Since undercuts lead to plating defects after the structure is formed, a negative photosensitive epoxy resin composition capable of forming a pattern without undercuts is required. In the negative type photosensitive resin composition of the present embodiment, by further adding a resin having a constitutional unit represented by general formula (ahs1) to the epoxy group-containing compound (A) and the cationic photopolymerization initiator (I), a pattern that is less likely to cause undercut can be formed.

[0203] The negative photosensitive resin composition of this embodiment is useful as a material for producing a hollow sealing structure in an electronic component.

[0204] Furthermore, according to the negative type photosensitive resin composition of this embodiment, in the production of a hollow sealing structure, a film having a thickness required for a spacer can be formed, and high-resolution patterning can be achieved with a good shape and without leaving any residue.

[0205] Furthermore, the negative type photosensitive resin composition of the present embodiment is capable of patterning in the same manner even when a thick film is formed, and good characteristics can be obtained. Therefore, the negative type photosensitive resin composition of the present embodiment is also useful as a material for a photosensitive resist film.

[0206] (Photosensitive resist film) The photosensitive resist film of the present embodiment is formed by laminating, in this order, a photosensitive resin film formed using the photosensitive composition of the above-described embodiment and a cover film on a base film.

[0207] The photosensitive resist film of the present embodiment can be produced, for example, by applying the photosensitive composition of the above-described embodiment onto a base film, drying the composition to form a photosensitive resin film, and then laminating a cover film onto the photosensitive resin film. The photosensitive composition may be applied onto the substrate film by a suitable method using a blade coater, lip coater, comma coater, film coater or the like. The thickness of the photosensitive resin film is preferably 100 μm or less, and more preferably 5 to 50 μm.

[0208] The substrate film may be a known one, for example, a thermoplastic resin film. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate. The thickness of the substrate film is preferably 2 to 150 μm.

[0209] The cover film may be a known one, such as a polyethylene film, a polypropylene film, etc. The cover film is preferably a film having a smaller adhesive strength with the photosensitive resin film than the base film. The thickness of the cover film is preferably 2 to 150 μm, more preferably 2 to 100 μm, and further preferably 5 to 50 μm. The base film and the cover film may be made of the same film material, or different film materials.

[0210] (Pattern formation method) The pattern forming method of the present embodiment includes a step of forming a photosensitive resin film on a support using the negative photosensitive resin composition of the above-described embodiment (hereinafter referred to as a "film forming step"), a step of exposing the photosensitive resin film (hereinafter referred to as an "exposure step"), and a step of developing the exposed photosensitive resin film with a developer containing an organic solvent to form a negative pattern (hereinafter referred to as a "development step"). The pattern forming method of this embodiment can be carried out, for example, as follows.

[0211] [Film formation process] First, the photosensitive composition of the above-described embodiment is applied onto a support by a known method such as spin coating, roll coating, or screen printing, and then baked (post-applied bake (PAB)) for 2 to 60 minutes at a temperature of, for example, 50 to 150°C to form a photosensitive resin film. The film forming step can also be performed by disposing a photosensitive resin film, out of the above-mentioned photosensitive resist films, on a support.

[0212] The support is not particularly limited, and may be a conventionally known one, for example, a substrate for electronic components, a substrate on which a predetermined wiring pattern is formed, etc. More specifically, the substrate may be a substrate made of metal such as silicon, silicon nitride, titanium, tantalum, lithium tantalate (LiTaO3), niobium, lithium niobate (LiNbO3), palladium, titanium tungsten, copper, chromium, iron, or aluminum, or a glass substrate. The wiring pattern may be made of a material such as copper, aluminum, nickel, or gold.

[0213] The pattern formation method of the present embodiment is useful for, for example, lithium tantalate (LiTaO3) substrates and lithium niobate (LiNbO3) substrates for SAW devices mounted on communication terminals.

[0214] The thickness of the photosensitive resin film formed from the photosensitive composition is not particularly limited, but is preferably about 10 to 100 μm.

[0215] [Exposure process] Next, the formed photosensitive resin film is subjected to selective exposure using a known exposure device, such as exposure through a mask (mask pattern) on which a predetermined pattern is formed, or drawing by direct irradiation with an electron beam without using a mask pattern. After the selective exposure, baking (post-exposure bake (PEB)) is performed as necessary, for example, at a temperature of 80 to 150° C. for 40 to 1200 seconds, preferably 40 to 1000 seconds, more preferably 60 to 900 seconds.

[0216] The wavelength used for exposure is not particularly limited, and radiation such as ultraviolet rays having a wavelength of 300 to 500 nm, i-rays (wavelength 365 nm), or visible light is selectively irradiated (exposed). As the radiation source, a low pressure mercury lamp, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, an argon gas laser, etc. can be used. Here, radiation means ultraviolet light, visible light, far ultraviolet light, X-rays, electron beams, etc. The radiation dose varies depending on the type and amount of each component in the composition, the thickness of the coating film, etc. For example, when an ultra-high pressure mercury lamp is used, it is 100 to 2000 mJ / cm. 2 It is.

[0217] The exposure method for the photosensitive resin film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography.

[0218] 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 2.7%. As described above, the photosensitive resin film formed using the photosensitive composition of the embodiment described above has high transparency, which increases light transmittance during exposure in pattern formation, making it easier to obtain a negative pattern with good lithography properties. The haze value of the photosensitive resin film after such an exposure step is measured using a method in accordance with JIS K 7136 (2000).

[0219] [Development process] Next, the photosensitive resin film after the exposure is developed with a developer containing an organic solvent (organic developer). After the development, a rinse treatment is preferably performed. If necessary, a bake treatment (post-bake) may be performed.

[0220] The organic solvent contained in the organic developer may be any solvent capable of dissolving the component (A) (the component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents.

[0221] 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.

[0222] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethoxyethyl acetate, propylene glycol monomethyl ether acetate (PGMEA), ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, Pyrene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, milk Examples of the lactate include ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate.Among these, the ester solvent is preferably butyl acetate or PGMEA.

[0223] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0224] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants. The surfactant is preferably a non-ionic surfactant, and more preferably a non-ionic fluorine-based surfactant or a non-ionic silicon-based surfactant. When a surfactant is added, the amount added is usually from 0.001 to 5 mass %, preferably from 0.005 to 2 mass %, and more preferably from 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0225] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it still for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0226] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously applying the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), or a method of spraying the rinse liquid onto the surface of the support (spray method). The rinsing treatment is preferably carried out using a rinsing liquid containing an organic solvent.

[0227] A pattern can be formed by the above-mentioned film forming step, exposure step, and development step.

[0228] In the pattern formation method of the embodiment described above, since the negative photosensitive resin composition which is one aspect described above is used, a pattern in which the occurrence of undercuts is suppressed can be formed in the pattern formation.

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

[0230] (Method of manufacturing the cured film) The method for producing a cured film of the present embodiment includes a step (i) of forming a photosensitive resin film on a support using the negative type photosensitive resin composition of the above-mentioned embodiment, and a 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 in the above-mentioned [film formation step]. The baking treatment can be performed, for example, at a temperature of 80 to 150° C. for 40 to 600 seconds. The curing treatment in step (ii) can be carried out under conditions of, for example, a temperature of 100 to 250° C. and a time of 0.5 to 2 hours.

[0231] The method for producing a cured film according to the embodiment may have other steps in addition to steps (i) and (ii). For example, the above-mentioned [exposure step] may be included between steps (i) and (ii), and the photosensitive 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 bake (PEB) treatment as necessary may be cured to obtain a cured film. According to the method for producing a cured film of the embodiment described above, the occurrence of undercuts is suppressed, and further, a cured film that faithfully reproduces a mask pattern can be easily produced. EXAMPLES

[0232] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0233] <Preparation of negative type photosensitive resin composition> (Comparative Example 1, Examples 1 to 7, Reference Example 1) Each component shown in Tables 1 and 2 was mixed and dissolved in 3-methoxybutyl acetate, and filtered using a PTFE filter (pore size 1 μm, manufactured by PALL Corporation) to prepare a negative type photosensitive resin composition (solution with a solid content of 60 to 65% by mass) for each example.

[0234] [Table 1]

[0235] [Table 2]

[0236] In Tables 1 and 2, the abbreviations have the following meanings: The numbers in brackets [ ] indicate the blending amount of each component (parts by mass; solid content equivalent). (A1)-1: Novolac-type epoxy resin represented by the following chemical formula (A1-1), product name "jER-157S70", manufactured by Mitsubishi Chemical Corporation.

[0237] [ka]

[0238] (A2)-1: A solid bisphenol-type epoxy resin represented by the following chemical formula (A2-1). Product name: "EPICLON 1055", manufactured by DIC Corporation. (A3)-1: An epoxy group-containing compound represented by the following chemical formula (A3-1), trade name "TEPIC-VL", manufactured by Nissan Chemical Industries, Ltd.

[0239] [ka]

[0240] (P)-1: Polyhydroxystyrene consisting of a repeating structure of the structural unit represented by the following chemical formula (P-1). Product name: "VP-8000", manufactured by Nippon Soda Co., Ltd. The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 8000, and the molecular weight dispersity (Mw / Mn) is 1.1.

[0241] [ka]

[0242] (I1)-1: A photocationic polymerization initiator represented by the following chemical formula (I1-5).

[0243] [ka]

[0244] (I2)-1: A photocationic polymerization initiator represented by the following chemical formula (I2-1-2). (I3)-1: A photocationic polymerization initiator represented by the following chemical formula (I3-1-1).

[0245] [ka]

[0246] (SC)-1: A compound represented by the following chemical formula (SC-1).

[0247] [ka]

[0248] <Pattern formation> Film formation process: Each negative photosensitive resin composition of the examples was applied onto a silicon substrate using a spinner, and the substrate was pre-baked (PAB) on a hot plate at a temperature of 115°C for 5 minutes, and then dried to form a photosensitive resin film with a thickness of 20 μm.

[0249] Exposure process: Next, the photosensitive resin film was irradiated with ghi rays with a gap of 30 μm. Thereafter, post-exposure baking was performed on a hot plate at 90° C. for 5 minutes.

[0250] Development process: Next, the substrate was developed for 120 seconds using propylene glycol monomethyl ether acetate (PGMEA) to form a negative pattern, resulting in the formation of a hole pattern with a diameter of 60 μm.

[0251] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (mJ / cm) for forming a hole pattern of the target size by the above <Pattern formation> 2 This is called "Eop(mJ / cm 2 ) are shown in Tables 3 and 4.

[0252] [Undercut evaluation] The cross-sectional shape of the hole pattern formed in the above <Pattern formation> was observed with a scanning electron microscope (product name: S4500; manufactured by Hitachi, Ltd.), and the occurrence of undercuts (notches in the peripheral portion of the negative pattern image (residual film) in contact with the silicon substrate) was evaluated based on the evaluation criteria shown in Figure 1. The results are shown in Tables 3 and 4.

[0253] The table shown in Figure 1 shows the evaluation criteria for undercuts. The photographs in the table are cross-sections of the hole patterns formed in the above <Pattern Formation>, observed with the above-mentioned scanning electron microscope. Reference numeral 10 denotes the silicon substrate, reference numeral 20 denotes the remaining film portion, and reference numeral 30 denotes the hole portion. The undercut is evaluated as C, B, or A depending on the state of the cut in the circled region, that is, the peripheral portion of the negative pattern image (residual film) in contact with the silicon substrate 10. If this evaluation is B, it means that the occurrence of undercut is suppressed. If this evaluation is an A, it means that the occurrence of undercuts is sufficiently suppressed.

[0254] [Table 3]

[0255] From the results shown in Table 3, it can be confirmed that the occurrence of undercuts was suppressed in the patterns formed using the negative photosensitive resin compositions of Examples 1 and 2 to which the present invention was applied.

[0256] In the pattern formed using the negative photosensitive resin composition of Comparative Example 1 containing an onium borate salt as a photocationic polymerization initiator, undercut occurred. On the other hand, in a pattern formed using the negative photosensitive resin composition of Reference Example 1 containing an onium salt whose anion moiety is a phosphorus-based anion as a photocationic polymerization initiator, the occurrence of undercut was suppressed. From these results, it can be confirmed that the undercut that occurs during pattern formation is specific to the use of an onium borate salt as a photocationic polymerization initiator.

[0257] [Table 4]

[0258] The results shown in Table 4 confirm that the occurrence of undercuts was more sufficiently suppressed in the patterns formed using the negative photosensitive resin compositions of Examples 3 to 7, which contained the component (A3) in addition to the components (A1) and (A2). [Explanation of symbols]

[0259] 10 silicon substrate, 20 remaining film portion, 30 hole portion

Claims

1. An epoxy group-containing compound (A), A photocationic polymerization initiator (I); A resin having a structural unit represented by the following general formula (ahs1), Contains The epoxy group-containing compound (A) contains a novolac type epoxy resin, The photocationic polymerization initiator (I) contains an onium borate salt, the content of the resin having a structural unit represented by the general formula (ahs1) is 0.5 to 10 parts by mass when the total amount of the epoxy group-containing compound (A) and the resin having a structural unit represented by the general formula (ahs1) is 100 parts by mass. [Formula 1] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ１ is a single bond or a divalent linking group. ｘ１ is an aromatic hydrocarbon group which may have a substituent. ａｘ１ is an integer of 1 or more.

2. The negative type photosensitive resin composition according to claim 1 , wherein the onium borate salt is a compound represented by the following general formula (I1): [Case 2] [In the formula, R ｂ０１ ~R ｂ０４ Each of the groups independently represents 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.

3. 3. The negative type photosensitive resin composition according to claim 1, wherein the novolac type epoxy resin is an epoxy resin represented by the following general formula (anv0): [C3] [In the formula, R ｐ１ and R ｐ２are 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. ＥＰ is an epoxy group-containing group. ＥＰ may be the same or different.

4. The negative type photosensitive resin composition according to any one of claims 1 to 3, wherein the epoxy group-containing compound (A) further contains a solid bisphenol type epoxy resin.

5. The negative photosensitive resin composition according to claim 4, wherein the solid bisphenol type epoxy resin is an epoxy resin represented by the following general formula (abp1): [C4] [In the formula, R ＥＰ is an epoxy group-containing group. ＥＰ may be the same or different. ａ３１ and R ａ３２ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. ３１ is an integer from 1 to 50.

6. The negative type photosensitive resin composition according to any one of claims 1 to 5, wherein the epoxy group-containing compound (A) further contains a compound represented by the following general formula (ta1): [C5] [In the formula, R ＥＰ is an epoxy group-containing group. ＥＰ may be the same or different.

7. The content of the compound represented by the general formula (ta1) is 0.1 to 10 parts by mass when the total parts by mass of the epoxy group-containing compound (A) is 100 parts by mass. The negative type photosensitive resin composition according to claim 6.

8. A step of forming a photosensitive resin film on a support using the negative type photosensitive resin composition according to any one of claims 1 to 7; exposing the photosensitive resin film to light; developing the exposed photosensitive resin film with a developer containing an organic solvent to form a negative pattern; The pattern forming method comprises the steps of:

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