JP2022101132A - Negative type photosensitive resin composition and pattern formation method - Google Patents

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

The present invention relates to a negative photosensitive resin composition and a pattern forming method.

In recent years, the development of minute electronic devices such as surface acoustic wave (SAW) filters has been promoted. The package encapsulating such an electronic device has a hollow structure for ensuring the propagation of surface acoustic waves and the mobility of movable members of the electronic device.
The package is formed by using a photosensitive resin composition to prepare a hollow structure in which the wiring board on which the electrodes are formed is kept hollow, and molding the package. In the photosensitive resin composition used here, it is necessary to make the cured film thinner and stronger.

The photosensitive resin composition is also used as a spacer (wall material) between the semiconductor wafer and the transparent substrate. For example, a negative type 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 and electron beam for development. After being treated to form a pattern, it is pressure-bonded to a transparent substrate (for example, a glass substrate) to form a spacer. In this photosensitive resin film, a film having a thickness required for a spacer is formed by a photolithography method, and high-resolution patterning is possible with a good shape and no residue. It needs to be possible.

In response to these demands, conventionally, as a photosensitive resin composition, one containing an epoxy resin and a photocationic polymerization initiator has been proposed. For example, the examples of Patent Document 1 disclose a negative photosensitive resin composition containing a specific epoxy resin and sulfonium borate as a photocationic polymerization initiator.

International Publication No. 2018/194154

However, in the conventional negative photosensitive resin composition such as the negative photosensitive resin composition described in Patent Document 1, when a negative pattern is formed on the surface of the semiconductor wafer by the blending balance thereof, the interface between the two is formed. There is a problem that a so-called undercut is likely to occur due to a cut in the peripheral portion of a negative pattern image (residual film) in contact with a semiconductor wafer. If this undercut occurs, it may lead to plating defects after the structure is formed.

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 in which undercut is less likely to occur in pattern formation, and a pattern forming method.

The present inventors have investigated that the problem of undercuts when forming a negative pattern using a negative photosensitive resin composition is that an anion portion is a borate anion as a photocationic polymerization initiator. It was found that it is particularly likely to appear remarkably when it is present. Then, they have found that the occurrence of undercut can be suppressed by using a resin having a structural unit containing a phenolic hydroxyl group in combination with respect to such a problem, and have completed the present invention.

In order to solve the above problems, the present invention has adopted the following configuration.
That is, the first aspect of the present invention contains 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). The epoxy group-containing compound (A) is a negative type photosensitive resin composition, which comprises a novolak type epoxy resin, and the photocationic polymerization initiator (I) contains an onium borate salt.

［式中、Ｒは、水素原子、炭素原子数１～５のアルキル基、又は炭素原子数１～５のハロゲン化アルキル基である。Ｙａ^ｘ１は、単結合又は２価の連結基である。Ｗａ^ｘ１は、置換基を有してもよい芳香族炭化水素基である。ｎ_ａｘ１は、１以上の整数である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or divalent linking group. Wa ^x1 is an aromatic hydrocarbon group which may have a substituent. n _ax1 is an integer of 1 or more. ]

A second aspect of the present invention is a step of forming a photosensitive resin film on a support and a step of exposing the photosensitive resin film by using the negative photosensitive resin composition according to the first aspect. A pattern forming method comprising a step of developing a photosensitive resin film after exposure with a developing solution containing an organic solvent to form a negative pattern.

According to the present invention, it is possible to provide a negative photosensitive resin composition in which undercut is less likely to occur in pattern formation, and a pattern forming method.

It is a table which shows the evaluation criteria of the undercut in this Example.

In the present specification and claims, "aliphatic" is a concept relative to aromatics and means a group having no aromaticity, a compound having no aromaticity, or the like. Define.
Unless otherwise specified, the "alkyl group" shall include linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The "alkyl halide group" is a group in which a part or all of the hydrogen atom of the alkyl group is substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
"Fluorinated alkyl group" refers to a group in which a part or all of the hydrogen atom of the alkyl group is substituted with a fluorine atom.
The "constituent unit" means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
When describing "may have a substituent", a case where a hydrogen atom (-H) is substituted with a monovalent group and a case where a methylene group ( _-CH2- ) is substituted with a divalent group. And both are included.
"Exposure" is a concept that includes general irradiation of radiation.

(Negative photosensitive resin composition)
The negative photosensitive resin composition of the present embodiment (hereinafter, may be simply referred to as “photosensitive composition”) is a photocationic polymerization with an epoxy group-containing compound (A) (hereinafter, also referred to as “(A) component”). It contains an initiator (I) (hereinafter, also referred to as "(I) component") and a resin having a structural unit represented by the general formula (ahs1) (hereinafter, this resin is also referred to as "(P) component"). do.
When a photosensitive resin film is formed using such a photosensitive composition and the photosensitive resin film is selectively exposed, the cation portion of the component (I) is formed in the exposed portion of the photosensitive resin film. Decomposition produces an acid, and the action of the acid causes ring-opening polymerization of the epoxy group in the component (A), reducing the solubility of the component (A) in the developing solution containing the organic solvent. In the unexposed portion of the photosensitive resin film, the solubility of the component (A) in the developing solution containing the organic solvent does not change, so that the organic solvent is used between the exposed portion and the unexposed portion of the photosensitive resin film. There is a difference in solubility in the developing solution containing. Therefore, when the photosensitive resin film is developed with a developing solution containing an organic solvent, the unexposed portion is dissolved and removed, and a negative pattern is formed.

<Epoxy group-containing compound (A)>
Examples of the epoxy group-containing compound (component (A)) include compounds having a sufficient epoxy group in one molecule to form a negative pattern by exposure.
The component (A) used in the photosensitive composition of the present embodiment contains a novolak type epoxy resin (hereinafter, also referred to as “component (A1)”). As the component (A), in addition to the component (A1), other epoxy group-containing compounds may be used in combination. However, the component (A) shall exclude those corresponding to the silane coupling agent.

≪Novolak type epoxy resin≫
As the novolak type epoxy resin (component (A1)), an epoxy resin represented by the following general formula (anv0) is preferably mentioned.

［式中、Ｒ^ｐ１及びＲ^ｐ２は、それぞれ独立に、水素原子又は炭素原子数１～５のアルキル基である。複数のＲ^ｐ１は、互いに同一であってもよく異なっていてもよい。複数のＲ^ｐ２は、互いに同一であってもよく異なっていてもよい。ｎ_１は、１～５の整数である。Ｒ^ＥＰは、エポキシ基含有基である。複数のＲ^ＥＰは、互いに同一であってもよく異なっていてもよい。］

[In the formula, R ^p1 and R ^p2 are independently alkyl groups having 1 to 5 hydrogen atoms or 1 to 5 carbon atoms. The plurality of R ^p1s may be the same as or different from each other. The plurality of R ^p2s may be the same as or different from each other. n ₁ is an integer of 1 to 5. R ^EP is an epoxy group-containing group. The plurality of R ^EPs may be the same as or different from each other. ]

In the above formula (anv0), the alkyl group having 1 to 5 carbon atoms of R ^p1 and R ^p2 is, for example, a linear, branched or cyclic alkyl group having 1 to 5 carbon atoms. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group and the like. .. Examples of the cyclic alkyl group include a cyclobutyl group and a cyclopentyl group.
Among them, as R ^p1 and R ^p2 , 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), the plurality of R ^p1s may be the same or different from each other. The plurality of R ^p2s may be the same as or different from each other.

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

In the above formula (anv0), R ^EP is an epoxy group-containing group.
The epoxy group-containing group of ^REP is not particularly limited, and is a group consisting only of an epoxy group; a group consisting only of an alicyclic epoxy group; an epoxy group or an alicyclic epoxy group and a divalent linking group. A group having and can be mentioned.
The alicyclic epoxy group is an alicyclic group having an oxacyclopropane structure which is a 3-membered ring ether, and specifically, a group having an alicyclic group and an oxacyclopropane structure.
The alicyclic group which 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, a cyclooctyl group and the like. Examples of the polycyclic alicyclic group include a norbornyl group, an isobornyl group, a tricyclononyl group, a tricyclodecyl group, a tetracyclododecyl group and the like. Further, 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, the epoxy group or the alicyclic epoxy group is via a divalent linking group bonded to an oxygen atom (—O—) in the formula. It is preferable that the groups are bonded.

Here, the divalent linking group is not particularly limited, but a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like are preferable.

For divalent hydrocarbon groups that may have substituents:
The divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
The aliphatic hydrocarbon group in the divalent hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in its structure, and the like.

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. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ -(CH ₂ ) _3- ], tetramethylene group [-(CH ₂ ) _4- ], pentamethylene group [-(CH ₂ ) _5- ] and the like can be mentioned.
The branched-chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 6, further preferably 2 to 4, and most preferably 2 or 3. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ). _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) ₂ -etc. Alkyl methylene groups;- CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- , -C (CH ₂ ) CH ₃ ) ₂ -CH ₂ -etc. Alkylethylene groups; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ -etc. Alkyltrimethylene groups; -CH (CH ₃ ) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH _2- , −CH ₂ CH (CH ₃ ) CH ₂ CH _2- and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

As the aliphatic hydrocarbon group containing a ring in the structure, an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an alicyclic hydrocarbon ring) and an alicyclic hydrocarbon group are linear or branched. Examples thereof include a group bonded to the end of a chain-shaped aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. Examples of the linear or branched aliphatic hydrocarbon group include the same groups as described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. 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 obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically. Examples include adamantan, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

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 a monocyclic type or a polycyclic type. 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; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings. A group from which two hydrogen atoms have been removed from (for example, biphenyl, fluorene, etc.); one of the hydrogen atoms of the group (aryl group or heteroaryl group) from which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocyclic ring. Hydrogen from an aryl group in an arylalkyl group such as a group substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group). A group from which one atom is further removed) and the like can be mentioned. The number of carbon atoms of the alkylene group bonded to the aryl group or the heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

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

The alicyclic hydrocarbon group in the aliphatic hydrocarbon group containing a ring in the structure as a divalent hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, a carbonyl group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are most preferable.
As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group are preferable. The methoxy group and the ethoxy group are most preferable.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include a group in which a part or all of the hydrogen atom of the alkyl group is substituted with the halogen atom.
In the alicyclic hydrocarbon group, a part of the carbon atom constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the heteroatom, —O—, —C (= O) —O—, —S—, —S (= O) _2- , —S (= O) ₂ -O— are preferable.

As 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, an alkyl halide group, a hydroxyl group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are most preferable.
Examples of the alkoxy group, the halogen atom and the alkyl halide group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the alicyclic hydrocarbon group.

About divalent linking groups containing heteroatoms:
The hetero atom in the divalent linking group including the hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

Among the divalent linking groups containing a heteroatom, the preferred linking groups are -O-, -C (= O) -O-, -C (= O)-, and -OC (= O). -O-; -C (= O) -NH-, -NH-, -NH-C (= O) -O-, -NH-C (= NH)-(H is a substitution of an alkyl group, an acyl group, etc.) It may be substituted with a group.); -S-, -S (= O) _2- , -S (= O) ₂ -O-, general formula-Y ²¹ -OY ^22- , -Y ²¹ -O-, -Y ²¹ -C (= O) -O-, -C (= O) -O-Y ²¹ ,-[Y ²¹ -C (= O) -O] _{m "} -Y ²² -or- Group represented by Y ²¹ -OC (= O) -Y ^22- [In the formula, Y ²¹ and Y ²² are divalent hydrocarbon groups which may have independent substituents. , O is an oxygen atom, and m "is an integer of 0 to 3. ] And so on.
When the divalent linking group containing the hetero atom is -C (= O) -NH-, -NH-, -NH-C (= O) -O-, -NH-C (= NH)- The H may be substituted with a substituent such as an alkyl group or an acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Equations-Y ²¹ -O-Y 22-, -Y ^{21-O-, -Y 21 -} C (= O) -O-, -C ^{(= O) -O-Y 21-,-[Y 21 - C} (= O) -O] _{m "} -Y ²² -or -Y ²¹ -OC (= O) -Y ²² -In, Y ²¹ and Y ²² each independently have a substituent. It is also a good divalent hydrocarbon group. As the divalent hydrocarbon group, the "divalent hydrocarbon group which may have a substituent may have a substituent" mentioned in the above description as the divalent linking group. The same thing can be mentioned.
As ^Y21 , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is preferable. Especially preferable.
As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkyl methylene group is more preferable. 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.
In the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- , m" is an integer of 0 to 3, preferably an integer of 0 to 2, and 0. Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- is represented by the formula-Y ²¹ -C ⁽ = O) -OY 22-. A group is particularly preferable. Among them, a group represented by the formula- (CH ₂ ) _a' -C (= O) -O- (CH ₂ ) b'-is preferable. In the formula, _a'is 1 to 1 to. It is an integer of 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 and 1 to 8. Is preferred, an integer of 1 to 5 is more preferred, 1 or 2 is even more preferred, and 1 is most preferred.

Of these, the glycidyl group is preferable as the epoxy group-containing group in ^REP .

Further, as the component (A1), a resin having a structural unit represented by the following general formula (anv1) is also preferably mentioned.

［式中、Ｒ^ＥＰは、エポキシ基含有基である。Ｒ^ａ２２及びＲ^ａ２３は、それぞれ独立に、水素原子、炭素原子数１～５のアルキル基又はハロゲン原子である。］

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

In the formula (anv1), the alkyl groups having 1 to 5 carbon atoms of R ^a22 and ^Ra23 are the same as the alkyl groups having 1 to 5 carbon atoms of R ^p1 and R ^p2 in the formula (anv0). ..
The halogen atom of R ^a22 and R ^a23 is preferably a chlorine atom or a bromine atom.
In the formula (anv1), the R ^EP is the same as the R ^EP in the formula (anv0), and a glycidyl group is preferable.

A specific example of the structural unit represented by the above formula (anv1) is shown below.

The component (A1) may be a resin composed of only the constituent unit (anv1), or may be a resin having the constituent unit (anv1) and another constituent unit.
Examples of other structural units include structural units represented by the following general formulas (anv2) to (anv3), respectively.

［式中、Ｒ^ａ２４は、置換基を有していてもよい炭化水素基である。Ｒ^ａ２５～Ｒ^ａ２６、Ｒ^ａ２８～Ｒ^ａ３０は、それぞれ独立に水素原子、炭素原子数１～５のアルキル基又はハロゲン原子である。Ｒ^ａ２７は、エポキシ基含有基又は置換基を有していてもよい炭化水素基である。］

[In the formula, ^Ra24 is a hydrocarbon group which may have a substituent. R ^a25 to ^Ra26 and R ^a28 to ^Ra30 are independently hydrogen atoms, alkyl groups having 1 to 5 carbon atoms, or halogen atoms, respectively. ^Ra27 is a hydrocarbon group which may have an epoxy group-containing group or a substituent. ]

In the above formula (anv2), ^Ra24 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 or a cyclic hydrocarbon group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group and the like. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

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

When ^Ra24 is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
The aliphatic hydrocarbon group which is a polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms. Examples include adamantan, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When the cyclic hydrocarbon group of ^Ra24 is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be a monocyclic type or a polycyclic type. 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; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, as the aromatic hydrocarbon group in ^Ra24 , a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle; and containing two or more aromatic rings. A group obtained by removing one hydrogen atom from an aromatic compound (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or the aromatic heterocycle is substituted with an alkylene group (for example, a benzyl group, etc.). Examples thereof include an arylalkyl group such as a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 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.

In the formulas (anv2) and (anv3), ^Ra25 to ^Ra26 and ^Ra28 to ^Ra30 are independently hydrogen atoms, alkyl groups having 1 to 5 carbon atoms, or halogen atoms.
The alkyl group and the halogen atom having 1 to 5 carbon atoms are the same as those of Ra ²² and Ra ²³ , respectively.

In the above formula (anv3), ^Ra27 is a hydrocarbon group which may have an epoxy group-containing group or a substituent. The epoxy group-containing group of R ^a27 is the same as R ^EP in the above formula (anv0). The hydrocarbon group which may have a substituent of R ^{a27 is} the same as that of Ra 24 in the above formula (anv2).

Specific examples of the structural units represented by the above equations (anv2) to (anv3) are shown below.

When the component (A1) has another structural unit in addition to the structural unit (anv1), the ratio of each structural unit in the component (A1) is not particularly limited, but constitutes the component (A1). The total amount of the structural units having an epoxy group is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, still more preferably 30 to 70 mol%, based on the total of all the structural units.

Commercially available products of the component (A1) include, for example, as novolak type epoxy resins, JER-152, JER-154, JER-157S70, JER-157S65 (all manufactured by Mitsubishi Chemical Corporation), EPICLON N-740, EPICLON N. -740, EPICLON N-770, EPICLON N-775, EPICLON N-660, EPICLON N-665, EPICLON N-670, EPICLON N-673, EPICLON N-680, EPICLON N-690, EPICLON N-695, EPICL (The above is manufactured by DIC Corporation), EOCN-1020 (above, manufactured by Nippon Kayaku Corporation) and the like.

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 the present embodiment, the content of the component (A1) is preferably 10 to 40 parts by mass, preferably 15 to 35 parts by mass when the total mass part of the component (A) is 100 parts by mass. It is more preferably parts by mass, and even more preferably 20 to 30 parts by mass.

≪Other epoxy group-containing compounds≫
As the epoxy group-containing compound other than the above component (A1), for example, a resin having a glycidyl ether group in its structure can be used.
Examples of the epoxy group-containing compound other than the component (A1) include bisphenol type epoxy resin, aliphatic epoxy resin, acrylic resin and the like.

About bisphenol type epoxy resin:
The bisphenol type epoxy resin (hereinafter, also referred to as “(A2) component”) may be any resin having a structural unit containing a bisphenol skeleton, and among them, a solid bisphenol type epoxy resin is preferable.
The solid bisphenol type epoxy resin refers to a resin having a structural unit containing a bisphenol skeleton, which is solid at 25 ° C.
The epoxy equivalent in the component (A2) is, for example, 800 g / eq. The above is preferable, and 800 to 1200 g / eq. Is more preferable, and 900 to 1100 g / eq. Is even more preferable.

As the component (A2), an epoxy resin represented by the following general formula (abp1) is preferably mentioned.

［式中、Ｒ^ＥＰは、エポキシ基含有基である。複数のＲ^ＥＰは、互いに同一であってもよく異なっていてもよい。Ｒ^ａ３１及びＲ^ａ３２は、それぞれ独立に、水素原子、炭素原子数１～５のアルキル基、又は炭素原子数１～５のフッ素化アルキル基である。ｎａ^３１は、１～５０の整数である。］

[In the formula, R ^EP is an epoxy group-containing group. The plurality of R ^EPs may be the same as or different from each other. R ^a31 and R ^a32 are independently hydrogen atoms, alkyl groups having 1 to 5 carbon atoms, or fluorinated alkyl groups having 1 to 5 carbon atoms. na ³¹ is an integer from 1 to 50. ]

In the formula (abp1), the R ^EP is the same as the R ^EP in the formula (anv0), and a glycidyl group is preferable.
In the formula (abp1), the alkyl groups having 1 to 5 carbon atoms in Ra 31 and Ra ³² are the same as the alkyl groups having 1 to 5 carbon atoms in R ^p1 and R ^p2 in the formula ( ^anv0 ). .. Of these, as R ^a31 and R ^a32 , hydrogen atoms or methyl groups are preferable, respectively.
In R ^a31 and Ra ³² , the fluorinated alkyl group having 1 to 5 carbon atoms is replaced with a fluorine atom in part or all of the hydrogen atom of the alkyl group having 1 to 5 carbon atoms in Ra ³¹ and Ra ³² . Fluorine can be mentioned.
In the above formula (abp1), na ³¹ is an integer of 1 to 50, preferably an integer of 4 to 15, and more preferably an integer of 5 to 8.

Commercially available products that can be used as the (A2) component are, for example, JER-4005, JER-4007, 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, JER-1010 (above, manufactured by Mitsubishi Chemical Corporation); Can be mentioned.

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 the present embodiment, the content of the component (A2) is preferably 60 to 90 parts by mass, preferably 65 to 85 parts when the total mass part of the component (A) is 100 parts by mass. It is more preferably parts by mass, and even more preferably 70 to 80 parts by mass.

When the component (A1) and the component (A2) are used in combination, the ratio of the component (A1) to the component (A2) is 1/9 or more as the mass ratio represented by the component (A1) / component (A2). It is preferably 5/5 or less, more preferably 1/9 or more and less than 5/5, further preferably 2/8 or more and 4/6 or less, and 2/8 or more and 3/7 or less. Is particularly preferred.
When the mass ratio is within the above-mentioned preferable range, the resolution is further enhanced and the adhesion to the substrate is also excellent.

About aliphatic epoxy resin:
As the aliphatic epoxy resin, for example, a compound represented by the following general formula (ta1) (hereinafter, this compound is also referred to as “(A3) component”) is preferably mentioned.
By using the component (A3) in combination, undercut is less likely to occur in pattern formation.

［式中、Ｒ^ＥＰは、エポキシ基含有基である。複数のＲ^ＥＰは、互いに同一であってもよく異なっていてもよい。］

[In the formula, R ^EP is an epoxy group-containing group. The plurality of R ^EPs may be the same as or different from each other. ]

In the formula (ta1), R ^EP is an epoxy group-containing group, and is the same as R ^EP in the formula (anv0).

Commercially available products that can be used as the component (A3) include, for example, TEPIC, TEPIC-VL, TEPIC-PAS, TEPIC-G, TEPIC-S, TEPIC-SP, TEPIC-SS, TEPIC-HP, TEPIC-L, TEPIC-. Examples include TEPIC series (manufactured by Nissan Chemical Co., Ltd.) such as FL and TEPIC-UC; MA-DGIC, DA-MGIC, TOIC (manufactured by Shikoku Kasei Kogyo Co., Ltd.) and the like.

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 the present embodiment, the content of the component (A3) is preferably 0.1 to 10 parts by mass, preferably 0, when the total mass part of the component (A) is 100 parts by mass. .5 to 5 parts by mass is more preferable, and 1 to 3.5 parts by mass is further preferable.
When the content of the component (A3) is at least the lower limit of the above-mentioned preferable range, undercut is less likely to occur in pattern formation. On the other hand, when the content of the component (A3) is large, the sensitivity tends to decrease in pattern formation, and if it is equal to or less than the upper limit of the above-mentioned preferable range, good sensitivity is likely to be maintained.

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 “(m1) component”).

［式中、ｎ_２は、１～４の整数である。＊は結合手を示す。］

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

In the formula (m1), n ₂ is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2.

Examples of the component (m1) include compounds 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 preferable.
The divalent linking group here is not particularly limited, and examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a heteroatom.
Here, a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom have been described in REP (epoxy group-containing group) in the above formula ( ^anv0 ). , A divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom are the same, and among these, a divalent linking group containing a hetero atom is preferable, ^−Y21 −. A group represented by C (= O) -O- and a group represented by -C (= O) -OY ²¹ -are more preferable. As ^Y21 , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is preferable. Especially preferable.

Commercially available products that can be used as the aliphatic epoxy resin include, for example, ADEKA RESIN EP-4080S, EP-4085S, EP-4088S (all manufactured by ADEKA Corporation); Selokiside 8000, Selokiside 8010, EHPE-3150, EPOLEAD PB 3600, PB 4700 (all manufactured by Daicel Co., Ltd.); Denacol EX-211L, EX-212L, EX-214L, EX-216L, EX-321L, EX-850L (The above is manufactured by Nagase ChemteX Corporation) and the like.

About acrylic resin:
Examples of the acrylic resin include resins having epoxy group-containing units represented by the following general formulas (a1-1) to (a1-2).

［式中、Ｒは水素原子、炭素原子数１～５のアルキル基、又は炭素原子数１～５のハロゲン化アルキル基である。Ｖａ^４１は、置換基を有していてもよい２価の炭化水素基である。ｎａ^４１は０～２の整数である。Ｒ^ａ４１及びＲ^ａ４２はそれぞれエポキシ基含有基である。ｎａ^４２は、０又は１である。Ｗａ^４１は、（ｎａ^４３＋１）価の脂肪族炭化水素基である。ｎａ^４３は１～３の整数である。］

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

In the above formula (a1-1), the alkyl group having 1 to 5 carbon atoms in R is preferably linear or branched, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, and the like. Examples thereof include an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
The alkyl halide group having 1 to 5 carbon atoms in R is a group in which a part or all of the hydrogen atoms of 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, an iodine atom and the like, and a fluorine atom is particularly preferable.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable from the viewpoint of industrial availability.

In the formula (a1-1), Va ⁴¹ is a divalent hydrocarbon group which may have a substituent and has the substituent described in REP in the formula ( ^anv0 ). Examples thereof include groups similar to the divalent hydrocarbon group which may be used.
Among the above, the hydrocarbon group of Va ⁴¹ is preferably an aliphatic hydrocarbon group, more preferably a linear or branched aliphatic hydrocarbon group, and further preferably a linear aliphatic hydrocarbon group. Linear alkylene groups are particularly preferred.

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

In the above formulas (a1-1) and (a1-2), R ^a41 and R ^a42 are epoxy group-containing groups, and are the same as R ^EP in the above formula (anv0).

In the above formula (a1-2), the (na ⁴³ +1) valent aliphatic hydrocarbon group in Wa ⁴¹ means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated. It may be saturated, and it is usually preferable that it is saturated. The aliphatic hydrocarbon group includes a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group. And a group combining an aliphatic hydrocarbon group containing a ring in the structure can be mentioned.

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

Hereinafter, specific examples of the structural units represented by the above formula (a1-1) or (a1-2) will be shown.
In the formula below, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.
R ^a51 represents a divalent hydrocarbon group having 1 to 8 carbon atoms. R ^a52 represents a divalent hydrocarbon group having 1 to 20 carbon atoms. R ^a53 represents a hydrogen atom or a methyl group. na ⁵¹ is an integer of 0 to 10.
R ^a51 , R ^a52 , and R ^a53 may be the same or different from each other.

Further, the acrylic resin may have a structural unit derived from another polymerizable compound for the purpose of appropriately controlling physical and chemical properties.
Examples of such a polymerizable compound include known radically polymerizable compounds and anionic 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; 2-methacryloyloxyethyl succinic acid and 2-methacryloyloxy. Methacrylic acid derivatives having a carboxyl group and an ester bond such as ethylmaleic acid, 2-methacryloyloxyethylphthalic acid, 2-methacryloyloxyethylhexahydrophthalic acid; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth). ) (Meth) acrylic acid alkyl esters such as acrylate; (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; phenyl (meth) acrylate, benzyl ( (Meth) acrylic acid aryl esters such as acrylates; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α- Vinyl group-containing aromatic compounds such as methylhydroxystyrene and α-ethylhydroxystyrene; Vinyl group-containing aliphatic compounds such as vinyl acetate; conjugated diolefins such as butadiene and isoprene; nitrile groups such as acrylonitrile and methacrylic nitrile Containing polymerizable compounds; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylic acid can be mentioned.

When the above acrylic resin has other structural units, the content ratio of the epoxy group-containing unit in the resin is preferably 5 to 40 mol%, more preferably 10 to 30 mol%, and 15 to 15 to 30 mol%. It is more preferably 25 mol%.

In addition to the above-mentioned resin, the compound represented by the following chemical formula (A3-1) and the compound represented by the following chemical formula (A3-2) are used as the epoxy group-containing compound other than the above-mentioned component (A1). You may.
Examples of commercially available products that can be used as the compound represented by the following chemical formula (A3-1) include 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) and the like.

Examples of the epoxy group-containing compound other than the above component (A1) include trimethylolpropane triglycidyl ether and glycerin triglycidyl ether; pentaerythritol tetraglycidyl ether, ditrimethylol propanetetraglycidyl ether, diglycerin tetraglycidyl ether and erythritol. Tetraglycidyl ether; xylitol pentaglycidyl ether, dipentaerythritol pentaglycidyl ether, inositol pentaglycidyl ether; dipentaerythritol hexaglycidyl ether, sorbitol hexaglycidyl ether, inositol hexaglycidyl ether and the like can also be mentioned.

In the photosensitive composition of the present embodiment, the component (A) contains the component (A1).
As the component (A), a component containing the component (A1) and the component (A2) is preferable, and a component containing the component (A1) and a solid bisphenol type epoxy resin is more preferable, and the general formula (anv0) is used. Those containing an epoxy resin represented by the general formula (abp1) and an epoxy resin represented by the general formula (abp1) are more preferable.
Further, as the component (A), a component containing the component (A1), the component (A2) and the component (A3) is particularly preferable.

The polystyrene-equivalent mass average molecular weight of the component (A) is preferably 100 to 300,000, more preferably 200 to 200,000, and further preferably 300 to 200,000. By setting such a mass average molecular weight, peeling from the support is less likely to occur, and the strength of the formed cured film is sufficiently increased.

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 and the like.

<Photocationic polymerization initiator (I)>
The photocationic polymerization initiator (component (I)) is irradiated with ultraviolet rays, far ultraviolet rays, excimer laser light such as KrF and ArF, and active energy rays such as X-rays and electron beams to generate cations, and the cations are generated. It is a compound that can be a polymerization initiator.
The component (I) used in the photosensitive composition of the present embodiment contains an onium borate salt (hereinafter, also referred to as “component (I1)”).
As the component (I), in addition to the component (I1), other photocationic polymerization initiators may be used in combination.

As described above, when a negative pattern is conventionally formed using a negative photosensitive resin composition, undercut is likely to occur when a photocationic polymerization initiator having a borate anion as an anion portion is used. There is a peculiar problem. The photosensitive composition of the present embodiment containing an onium borate salt is useful for such a problem.

≪Onium borate salt≫
The onium borate salt (component (I1)) produces a relatively strong acid upon exposure. Therefore, by forming a pattern using the photosensitive composition containing the component (I1), sufficient sensitivity is obtained and a good pattern is formed. Further, the use of the component (I1) has a low risk of toxicity and metal corrosion.
As the component (I1), for example, a compound represented by the following general formula (I1) is preferably mentioned.

［式中、Ｒ^ｂ０１～Ｒ^ｂ０４は、それぞれ独立に、置換基を有してもよいアリール基、又はフッ素原子である。ｑは１以上の整数であって、Ｑ^ｑ＋は、ｑ価の有機カチオンである。］

[In the formula, R ^b01 to R ^b04 are aryl groups or fluorine atoms which may independently have a substituent. q is an integer of 1 or more, and Q ^{q +} is a q-valent organic cation. ]

-Anion portion In the above formula (I1), the aryl group in R ^b01 to R ^b04 preferably has 5 to 30 carbon atoms, more preferably 5 to 20, further preferably 6 to 15, and 6 to 12 Is particularly preferable. Specific examples thereof include a naphthyl group, a phenyl group, an anthrasenyl group and the like, and a phenyl group is preferable because it is easily available.
The aryl group in R ^b01 to R ^b04 may have a substituent. The substituent is not particularly limited, but is a halogen atom, a hydroxyl group, an alkyl group (preferably a linear or branched alkyl group, preferably 1 to 5 carbon atoms), an alkyl halide. A group is preferable, a halogen atom or an alkyl halide group having 1 to 5 carbon atoms is more preferable, and a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms is particularly preferable. It is preferable that the aryl group has a fluorine atom because the polarity of the anion portion is increased.
Among them, as R ^b01 to R ^b04 of the formula (I1), a fluorinated phenyl group is preferable, and a perfluorophenyl group is particularly preferable.

Preferred specific examples of the anion moiety of the compound represented by the formula (I1) are tetrakis (pentafluorophenyl) borate ([B _{(C6 F 5) 4 ] -} ⁾ ; tetrakis [(trifluoromethyl) phenyl]. Borate ([B (C ₆ H ₄ CF ₃ ) ₄ ] ^- ); Difluorobis (pentafluorophenyl) borate ([(C ₆ F ₅ ) ₂ BF ₂ ] ^- ); Trifluoro (pentafluorophenyl) borate ([ (C ₆ F ₅ ) BF ₃ ] ^- ); Tetrakiss (difluorophenyl) borate ([B (C ₆ H ₃ F ₂ ) ₄ ] ^- ) and the like can be mentioned.
Of these, tetrakis (pentafluorophenyl) borate ([B (C ₆ F ₅ ) ₄ ] ^- ) is particularly preferable.

-Cation part In the above formula (I1), sulfonium cation and iodonium cation are preferably mentioned as Q ^{q +} , and organic cations represented by the following general formulas (ca-1) to (ca-5) are particularly preferable. preferable.

［式中、Ｒ^２０１～Ｒ^２０７、およびＲ^２１１～Ｒ^２１２は、それぞれ独立に、置換基を有していてもよいアリール基、ヘテロアリール基、アルキル基またはアルケニル基を表す。Ｒ^２０１～Ｒ^２０３、Ｒ^２０６～Ｒ^２０７、Ｒ^２１１～Ｒ^２１２は、相互に結合して、式中のイオウ原子と共に環を形成してもよい。Ｒ^２０８～Ｒ^２０９は、それぞれ独立に、水素原子または炭素原子数１～５のアルキル基を表す。Ｒ^２１０は、置換基を有していてもよいアリール基、置換基を有していてもよいアルキル基、置換基を有していてもよいアルケニル基、または置換基を有していてもよい－ＳＯ_２－含有環式基である。Ｌ^２０１は、－Ｃ（＝Ｏ）－または－Ｃ（＝Ｏ）－Ｏ－を表す。Ｙ^２０１は、それぞれ独立に、アリーレン基、アルキレン基またはアルケニレン基を表す。ｘは、１または２である。Ｗ^２０１は、（ｘ＋１）価の連結基を表す。］

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

Examples of the aryl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
Examples of the heteroaryl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² include those in which a part of the carbon atom constituting the aryl group is replaced with a hetero atom. Examples of the hetero atom include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Examples of the heteroaryl group include a group obtained by removing one hydrogen atom from 9H-thioxanthene; and examples of the substituted heteroaryl group include a group obtained by removing one hydrogen atom from 9H-thioxanthene-9-one.
The alkyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² preferably has 2 to 10 carbon atoms.
Examples of the substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have include an alkyl group, a halogen atom, an alkyl halide group, a carbonyl group, a cyano group, an amino group, and an oxo group (=). Examples thereof include O), an aryl group, and a group represented by the following formulas (ca-r-1) to (ca-r-10), respectively.

［式中、Ｒ’^２０１は、それぞれ独立に、水素原子、置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。］

[In the formula, ^R'201 independently has a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group that may be present. ]

In the above formulas (ca-r-1) to (ca-r-10), ^R'201 independently has a hydrogen atom and a cyclic group and a substituent which may have a substituent. It is a chain-like alkyl group which may be present, or a chain-like alkenyl group which may have a substituent.

Cyclic group which may have a substituent:
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. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

The aromatic hydrocarbon group in ^R'201 is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more 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.
Specifically, as the aromatic ring of the aromatic hydrocarbon group in ^R'201 , benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of carbon atoms constituting these aromatic rings is substituted with a hetero atom. Examples thereof include aromatic heterocycles, or rings in which a part of hydrogen atoms constituting these aromatic rings or aromatic heterocycles is substituted with an oxo group or the like. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like.
Specifically, as the aromatic hydrocarbon group in ^R'201 , a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, anthracenyl group, etc.), a hydrogen atom of the aromatic ring. A group in which one of the groups is substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), A group obtained by removing one hydrogen atom from a ring in which a part of the hydrogen atom constituting the aromatic ring is substituted with an oxo group or the like (for example, anthraquinone), an aromatic heterocycle (for example, 9H-thioxanthene, 9H-thioxanthene). A group obtained by removing one hydrogen atom from -9-on, etc.) can be mentioned. The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

Examples of the cyclic aliphatic hydrocarbon group in ^R'201 include an aliphatic hydrocarbon group containing a ring in the structure.
As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an alicyclic hydrocarbon ring) and an alicyclic hydrocarbon group are linear or branched. Examples thereof include a group bonded to the end of a chain-shaped aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. 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 obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among them, the polycycloalkane is a polycycloalkane having a polycyclic skeleton of a crosslinked ring system such as adamantan, norbornane, isobornane, tricyclodecane, and tetracyclododecan; a fused ring system such as a cyclic group having a steroid skeleton. Polycycloalkanes having a polycyclic skeleton of are more preferred.

Among them, as the cyclic aliphatic hydrocarbon group in ^R'201 , a group in which one or more hydrogen atoms are removed from monocycloalkane or polycycloalkane is preferable, and a group in which one hydrogen atom is removed from polycycloalkane is preferable. More preferably, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

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, and 1 to 6 carbon atoms. 4 is more preferable, and 1 to 3 are most preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ -(CH ₂ ) _3- ], tetramethylene group [-(CH ₂ ) _4- ], pentamethylene group [-(CH ₂ ) _5- ] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ). _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) ₂ -etc. Alkyl methylene groups;- CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- , -C (CH ₂ ) CH ₃ ) ₂ -CH ₂ -etc. Alkylethylene groups; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ -etc. Alkyltrimethylene groups; -CH (CH ₃ ) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH _2- , −CH ₂ CH (CH ₃ ) CH ₂ CH _2- and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Chained alkyl group which may have a substituent:
The chain-like alkyl group of ^R'201 may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, 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 and a tetradecyl group. Examples thereof include a 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-chain alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples thereof include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.

Chain alkenyl group which may have a substituent:
The chain alkenyl group of ^R'201 may be either linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5, and even more preferably 2 to 4. 3 is particularly preferable. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), a butynyl group and the like. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, a 2-methylpropenyl group and the like.
Among the above, as the chain alkenyl group, a linear alkenyl group is preferable, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

Examples of the substituent in the cyclic group, chain-like alkyl group or alkenyl group of ^R'201 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group and an oxo group. Examples thereof include a cyclic group, an alkylcarbonyl group and a thienylcarbonyl group in ^R'201 .

Among them, ^R'201 is preferably a cyclic group which may have a substituent and a chain alkyl group which may have a substituent.

When R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , and R ²¹¹ to R ²¹² are bonded to each other to form a ring together with the sulfur atom in the formula, heteroatoms such as sulfur atom, oxygen atom, and nitrogen atom, and heteroatoms such as sulfur atom and nitrogen atom are formed. Carbonyl group, -SO-, -SO _2- , -SO _3- , -COO-, -CONH- or _-N (RN)-(The _RN is an alkyl group having 1 to 5 carbon atoms). It may be bonded via a functional group such as. As the ring to be formed, one ring containing a sulfur atom in its ring skeleton, including the sulfur atom, is preferably a 3- to 10-membered ring, and particularly preferably a 5- to 7-membered ring. preferable. Specific examples of the formed ring include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxatiin ring, tetrahydro. Examples thereof include a thiophenium ring and a tetrahydrothiopyranium ring.

In the above formula (ca-3), R ²⁰⁸ to R ²⁰⁹ independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable. When it becomes an alkyl group, it may be bonded to each other to form a ring.

In the above formula (ca-3), R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an alkenyl group which may have a substituent. It is a _—SO2 -containing cyclic group which may have a substituent.
Examples of the aryl group in R ²¹⁰ include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group in R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²¹⁰ preferably has 2 to 10 carbon atoms.

In the above formulas (ca-4) and (ca-5), Y ²⁰¹ independently represents an arylene group, an alkylene group or an alkaneylene group, respectively.
Examples of the arylene group in Y ²⁰¹ include a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group in ^R'201 .
Examples of the alkylene group and the alkaneylene group in Y ²⁰¹ include a chain-like alkyl group in ^R'201 and a group in which one hydrogen atom is removed from the group exemplified as the chain-like alkenyl group.

In the above formula (ca-4) and formula (ca-5), x is 1 or 2.
W ²⁰¹ is a (x + 1) valence, i.e., a divalent or trivalent linking group.
As the divalent linking group in W ²⁰¹ , a divalent hydrocarbon group which may have a substituent is preferable, and a substituent exemplified by ^REP in the above formula (A1) may be contained. Groups similar to divalent hydrocarbon groups are preferred. The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, and is preferably cyclic. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group or a group consisting of only an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. Can be mentioned. As the trivalent linking group in W ²⁰¹ , a group in which two carbonyl groups are bonded to an arylene group is preferable.

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

［式中、Ｒ”^２０１は、水素原子又は置換基である。該置換基としては、前記Ｒ^２０１～Ｒ^２０７およびＲ^２１０～Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[In the formula, R " ²⁰¹ is a hydrogen atom or a substituent. The substituents are the same as those listed as the substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have. Is.]

Further, as the cation represented by the above formula (ca-1), the cations represented by the following general formulas (ca-1-25) to (ca-1-35) are also preferable.

［式中、Ｒ’^２１１はアルキル基である。Ｒ^ｈａｌは、水素原子又はハロゲン原子である。］

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

Further, as the cation represented by the above formula (ca-1), the cations represented by the following chemical formulas (ca-1-36) to (ca-1-48) are also preferable.

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

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

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

Further, as the cation represented by the above formula (ca-5), the cations represented by the following general formulas (ca-5-1) to (ca-5-3) are also preferable.

［式中、Ｒ’^２１２はアルキル基又は水素原子である。Ｒ’^２１１はアルキル基である。］

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

Among the above, the cation portion [(Q ^{q +} ) _{1 / q} ] is preferably a cation represented by the general formula (ca-1), and is represented by the formulas (ca-1-1) to (ca-1-48), respectively. The cation represented is more preferable, the cation represented by the formula (ca-1-25), the cation represented by the formula (ca-1-29), the cation represented by the formula (ca-1-35), and the cation represented by the formula (ca-1-35). The cation represented by the formula (ca-1-47) and the cation represented by the formula (ca-1-48) are more preferable.

Specific examples of the suitable (I1) component are given below.

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 the present embodiment, the content of the component (I1) is preferably 0.1 to 5 parts by mass, preferably 0, when the total mass part of the component (A) is 100 parts by mass. .2 to 3 parts by mass is more preferable, and 0.5 to 1 part by mass is further preferable.
When the content of the component (I1) is at least the lower limit of the above-mentioned preferable range, sufficient sensitivity is obtained and the lithography characteristics of the pattern are further improved. In addition, the strength of the cured film is further increased. On the other hand, when it is not more than the upper limit of the above-mentioned preferable range, the sensitivity is appropriately controlled, and it becomes easy to obtain a pattern having a good shape.

≪Other photocationic polymerization initiators≫
Examples of the photocationic polymerization initiator other than the above component (I1) include a compound represented by the following general formula (I2) (hereinafter referred to as “(I2) component”), the following general formula (I3-1) or (I3). Examples thereof include the compound represented by -2) (hereinafter referred to as "(I3) component").

About the compound represented by the general formula (I2) (component (I2)):
The component (I2) is a compound represented by the following general formula (I2).
Since the component (I2) generates a relatively strong acid upon exposure, sufficient sensitivity can be obtained and a good pattern can be obtained when a pattern is formed using a photosensitive composition containing the component (I). It is formed.

［式中、Ｒ^ｂ０５は、置換基を有していてもよいフッ素化アルキル基、又はフッ素原子である。複数のＲ^ｂ０５は、互いに同一であってもよく異なっていてもよい。ｑは１以上の整数であって、Ｑ^ｑ＋は、ｑ価の有機カチオンである。］

[In the formula, R ^b05 is a fluorinated alkyl group or a fluorine atom which may have a substituent. The plurality of R ^b05s may be the same as or different from each other. q is an integer of 1 or more, and Q ^{q +} is a q-valent organic cation. ]

-Anion portion In the above formula (I2), R ^b05 is a fluorinated alkyl group or a fluorine atom which may have a substituent. The plurality of R ^b05s may be the same as or different from each other.
The fluorinated alkyl group in R ^b05 preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and even more preferably 1 to 5. Specifically, in the alkyl group having 1 to 5 carbon atoms, a group in which a part or all of a hydrogen atom is replaced with a fluorine atom can be mentioned.
Among them, as R ^b05 , a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms is more preferable, and a fluorine atom, a trifluoromethyl group or a trifluoromethyl group or Pentafluoroethyl groups are more preferred.

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

［式中、Ｒ^ｂｆ０５は、置換基を有していてもよいフッ素化アルキル基である。ｎｂ^１は、１～５の整数である。］

[In the formula, R ^bf05 is a fluorinated alkyl group which may have a substituent. nb ¹ is an integer of 1 to 5. ]

In the formula (b0-2a), the fluorinated alkyl group which may have a substituent in R ^bf05 is the same as the fluorinated alkyl group which may have a substituent described in R ^b05 . be.
In the 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.

-In the cation part equation (I2), q is an integer of 1 or more, and Q ^{q +} is a q-valent organic cation.
Examples of this Q ^{q +} include the same as Q ^q + in the above formula (I1), and among them, the cation represented by the general formula (ca-1) is preferable, and the formulas (ca-1-1) to The cations represented by (ca-1-48) are more preferable, the cations represented by the formula (ca-1-25), the cations represented by the formula (ca-1-29), and the cations represented by the formula (ca-1). The cation represented by -35) and the cation represented by the formula (ca-1-47) are more preferable.

Specific examples of the suitable (I2) component are given below.

About the compound represented by the 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).

［式中、Ｒ^ｂ１１～Ｒ^ｂ１２は、ハロゲン原子以外の置換基を有していてもよい環式基、ハロゲン原子以外の置換基を有していてもよい鎖状のアルキル基、又はハロゲン原子以外の置換基を有していてもよい鎖状のアルケニル基である。ｍは１以上の整数であって、Ｍ^ｍ＋は、それぞれ独立に、ｍ価の有機カチオンである。］

[In the formula, R ^b11 to R ^b12 are 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 halogen atom. It is a chain alkenyl group which may have a substituent other than the above. m is an integer of 1 or more, and M ^{m +} is an independently m-valent organic cation. ]

{(I3-1) component}
-In the anion part formula (I3-1), R ^b12 is a cyclic group which may have a substituent other than a halogen atom, and a chain alkyl group which may have a substituent other than a halogen atom. , Or a chain alkenyl group that may have a substituent other than a halogen atom, among the cyclic group, chain alkyl group, and chain alkenyl group described above in ^R'201 . , Those having no substituent or those having a substituent other than the halogen atom.
The 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-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10. As the aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from adamantan, norbornan, isobornan, tricyclodecane, tetracyclododecane and the like (may have a substituent other than a halogen atom); camphor. It is more preferable that the group is obtained by removing one or more hydrogen atoms from the above.
The hydrocarbon group of R ^b12 may have a substituent other than the halogen atom, and the substituent may be a hydrocarbon group (aromatic hydrocarbon group, fat) in R ^b11 of the above formula (I3-2). Examples thereof include substituents other than the halogen atom which the group ring group, the chain alkyl group may have).
The term "may have a substituent other than a halogen atom" as used herein means not only excluding the case of having a substituent consisting of only a halogen atom but also the case of having a substituent containing at least one halogen atom. (For example, when the substituent is a fluorinated alkyl group, etc.) is excluded.

Hereinafter, a preferable specific example of the anion portion of the component (I3-1) is shown.

-Cation part In formula (I3-1), M ^{m +} is an m-valent organic cation.
As the organic cation of M ^{m +} , the same cations as those represented by the above general formulas (ca-1) to (ca-5) are preferably mentioned, and among these, the above general formula (ca-1) is used. The cation represented by is more preferable. Among these, at least one of R ²⁰¹ , R ²⁰² , and R ²⁰³ in the above general formula (ca-1) may have a substituent and is an organic group having 16 or more carbon atoms (aryl group, hetero). A sulfonium cation (aryl group, alkyl group or alkenyl group) is particularly preferable because it improves resolution and roughness characteristics.
The substituents that the organic group may have are the same as above, and are an alkyl group, a halogen atom, an alkyl halide group, a carbonyl group, a cyano group, an amino group, an oxo group (= O), and an aryl. Groups and groups represented by the above formulas (ca-r-1) to (ca-r-10) can be mentioned.
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, such M. Examples of the ^{m +} organic cation include 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), respectively, are preferably mentioned, and among them, the cation represented by the above formula (ca-1-29) is particularly preferable.

{(I3-2) component}
-In the anion part formula (I3-2), R ^b11 is a cyclic group which may have a substituent other than a halogen atom, and a chain alkyl group which may have a substituent other than a halogen atom. , Or a chain alkenyl group that may have a substituent other than a halogen atom, among the cyclic group, chain alkyl group, and chain alkenyl group described above in ^R'201 . , Those having no substituent or those having a substituent other than the halogen atom.

Among these, as R ^b11 , 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 halogen. A chain alkyl group which may have a substituent other than an atom is preferable. Examples of the substituent that these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a lactone-containing cyclic group, an ether bond, an ester bond, or a combination thereof.
When an ether bond or an ester bond is contained as a substituent, an alkylene group may be used as a substituent. In this case, the substituents are shown in the following general formulas (y-al-1) to (y-al-7), respectively. Linking groups are preferred.
In the following general formulas (y-al-1) to (y-al-7), it is the following general formulas (y-al-1) to bond with R ^b11 in the above formula (I3-2). It is ^V'101 in (y-al-7).

［式中、Ｖ’^１０１は、単結合または炭素原子数１～５のアルキレン基である。Ｖ’^１０２は、炭素原子数１～３０の２価の飽和炭化水素基である。］

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

The divalent saturated hydrocarbon group in ^V'102 is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and 1 to 5 carbon atoms. It is more preferable that it is an alkylene group of.

The alkylene group in ^V'101 and ^V'102 may be a linear alkylene group or a branched chain alkylene group, and a linear alkylene group is preferable.
Specific examples of the alkylene group in ^V'101 and ^V'102 are methylene groups [-CH ₂ -];-CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, -C (CH ₃ ). _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) ₂ -etc. Alkyl methylene groups; ethylene Group [-CH ₂ CH _2- ]; -CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH) ₃ ) Alkylethylene groups such as CH _2- ; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH _2- ]; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) Alkyltrimethylene groups such as CH _2- ; Tetramethylene groups [-CH ₂ CH ₂ CH ₂ CH _2- ]; -CH (CH ₃ ) CH ₂ CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ Alkyltetramethylene groups such as CH _2- ; pentamethylene groups [-CH ₂ CH ₂ CH ₂ CH ₂ CH _2- ] and the like can be mentioned.
Further, a part of the methylene group in the alkylene group in ^V'101 or ^V'102 may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic ring-type group is obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of ^R'201 (monocyclic alicyclic hydrocarbon group, polycyclic alicyclic hydrocarbon group). A divalent group is preferable, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferable.

As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.
The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The chain-like alkyl group preferably has 1 to 10 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. , Nonyl group, linear alkyl group such as decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1- Examples thereof include branched alkyl groups such as ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.

As R ^b11 , a cyclic group which may have a substituent other than a halogen atom is preferable.
Hereinafter, a preferable specific example of the anion portion of the component (I3-2) is shown.

-Cation part In the formula (I3-2), M ^{m +} is an organic cation having an m valence, which is the same as M ^{m +} in the formula (I3-1).

Further, the component (I) is a cationic polymerization initiator that generates an acid having a pKa (acid dissociation constant) of -5 or less by exposure because of the high elasticity of the resin film and the tendency to form a fine structure without residue. It is preferable to have. High sensitivity to exposure can be obtained by using a cationic polymerization initiator that generates an acid having a pKa of -6 or less, more preferably -8 or less. (I) The lower limit of the pKa of the acid generated by the component is preferably -15 or more. By using such a cationic polymerization initiator that generates a suitable pKa acid, high sensitivity can be easily achieved.
Here, "pKa (acid dissociation constant)" refers to a substance generally used as an index indicating the acid strength of the target substance. In addition, pKa in this specification is a value under the temperature condition of 25 degreeC. Further, the pKa value can be measured and obtained by a known method. Further, calculated values using known software such as "ACD / Labs" (trade name, manufactured by Advanced Chemistry Development) can also be used.

Specific examples of the suitable (I3) component are given below.

In the photosensitive composition of the present embodiment, the component (I) contains the component (I1).
Preferable examples of the component (I) include those composed of only the component (I1) and those containing the component (I1) and the component (I3).

In the photosensitive composition of the present embodiment, the total content of the component (I) is preferably 0.1 to 5 parts by mass when the total mass part of the component (A) is 100 parts by mass. It is more preferably 0.2 to 3 parts by mass, and even more preferably 0.5 to 1 part by mass.
When the content of the component (I) is at least the lower limit of the above-mentioned preferable range, sufficient sensitivity is obtained and the lithography characteristics of the pattern are further improved. In addition, the strength of the cured film is further increased. On the other hand, when it is not more than the upper limit of the above-mentioned preferable range, the sensitivity is appropriately controlled, and it becomes easy to obtain a pattern having a good shape.

<Resin having a structural unit represented by the general formula (ahs1)>
In the photosensitive composition of the present embodiment, the component (P) is a resin having a structural unit represented by the general formula (ahs1) (hereinafter, also referred to as “constituent unit (u1)”).
By containing the component (P), undercut is less likely to occur in pattern formation.

About the structural unit (u1):
The structural unit (u1) is a structural unit represented by the following general formula (ahs1).

［式中、Ｒは、水素原子、炭素原子数１～５のアルキル基、又は炭素原子数１～５のハロゲン化アルキル基である。Ｙａ^ｘ１は、単結合又は２価の連結基である。Ｗａ^ｘ１は、置換基を有してもよい芳香族炭化水素基である。ｎ_ａｘ１は、１以上の整数である。］

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or divalent linking group. Wa ^x1 is an aromatic hydrocarbon group which may have a substituent. n _ax1 is an integer of 1 or more. ]

In the above formula (ahs1), the alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group or an ethyl group. , Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
The alkyl halide group having 1 to 5 carbon atoms in R is a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom, a methyl group or a trifluoromethyl group is preferable because of easy industrial availability. Is more preferable, a hydrogen atom or a methyl group is further preferable, and a methyl group is particularly preferable.

In the formula (ahs1), Ya ^x1 is a single bond or a divalent linking group.
In the above chemical formula, the divalent linking group in Ya ^x1 is not particularly limited, but a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom and the like are suitable. Is mentioned as.

A divalent hydrocarbon group that may have a substituent:
When Ya ^x1 is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group in Ya ^x1 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 a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

... Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. , 1 to 4 carbon atoms are more preferable, and 1 to 3 carbon atoms are most preferable.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ -(CH ₂ ) _3- ], tetramethylene group [-(CH ₂ ) _4- ], pentamethylene group [-(CH ₂ ) _5- ] and the like can be mentioned.
The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and 3 carbon atoms. Most preferred.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, -CH (CH ₃ )-, -CH (CH ₂ CH ₃ )-, and -C (CH ₃ ). _2- , -C (CH ₃ ) (CH ₂ CH ₃ )-, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ )-, -C (CH ₂ CH ₃ ) ₂ -etc. Alkyl methylene groups;- CH (CH ₃ ) CH _2- , -CH (CH ₃ ) CH (CH ₃ )-, -C (CH ₃ ) ₂ CH _2- , -CH (CH ₂ CH ₃ ) CH _2- , -C (CH ₂ ) CH ₃ ) ₂ -CH ₂ -etc. Alkylethylene groups; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ -etc. Alkyltrimethylene groups; -CH (CH ₃ ) Examples thereof include alkylalkylene groups such as alkyltetramethylene groups such as CH ₂ CH ₂ CH _2- , −CH ₂ CH (CH ₃ ) CH ₂ CH _2- and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

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

... An aliphatic hydrocarbon group containing a ring in the structure As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group may contain a substituent containing a hetero atom in the ring structure. (A group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, the cyclic fat. Examples thereof include a group in which a group 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 groups as described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. 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 obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically. Examples include adamantan, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, a carbonyl group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are more preferable.
As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group are more preferable. , A methoxy group and an ethoxy group are more preferable.
As the halogen atom as the substituent, a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include a group in which a part or all of the hydrogen atom of the alkyl group is substituted with the halogen atom.
The cyclic aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom as a part of the carbon atom constituting the ring structure. As the substituent containing the heteroatom, —O—, —C (= O) —O—, —S—, —S (= O) _2- , —S (= O) ₂ -O— are preferable.

Aromatic hydrocarbon group in Ya ^x1 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 a monocyclic type or a polycyclic type. The number of carbon atoms in the aromatic ring is preferably 5 to 30, 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; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings. A group from which two hydrogen atoms have been removed from (for example, biphenyl, fluorene, etc.); one of the hydrogen atoms of the group (aryl group or heteroaryl group) from which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocyclic ring. Hydrogen from an aryl group in an arylalkyl group such as a group substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group). A group from which one atom is further removed) and the like can be mentioned. The number of carbon atoms of the alkylene group bonded to the aryl group or the heteroaryl group is preferably 1 to 4, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom number. ..

In the aromatic 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, an alkyl halide group, a hydroxyl group and the like.
As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are more preferable.
Examples of the alkoxy group, the halogen atom and the alkyl halide group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

-A divalent linking group containing a heteroatom:
When Ya ^x1 is a divalent linking group containing a hetero atom, the preferred linking groups are -O-, -C (= O) -O-, -OC (= O)-,-. C (= O)-, -OC (= O) -O-, -C (= O) -NH-, -NH-, -NH-C (= NH)-(H is an alkyl group or an acyl group) , Etc.), -S-, -S (= O) _2- , -S (= O) ₂ -O-, general formula-Y ²¹ -OY ^22- , -Y ²¹ -O-, -Y ^{21-C (= O) -O-, -C (= O) -O-Y 21-,-[Y 21 - C} (= O) -O] _{m "} -Y ^22- , -Y ²¹ -OC (= O) -Y ^{22- or -Y 21 -} S (= O) ₂ -O-Y ^22- [In the formula, Y ²¹ and Y ²² are Each is a divalent hydrocarbon group which may have a substituent independently, O is an oxygen atom, and m "is an integer of 0 to 3. ] And so on.
The divalent linking group containing the hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH). In the case of −, the H may be substituted with a substituent such as an alkyl group or an acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
General formula-Y ²¹ -O-Y 22-, -Y ^{21-O-, -Y 21 -} C (= O) -O-, -C ⁽ = O) -O-Y ²¹ -,-[Y ^21- C (= O) -O] _{m "} -Y 22-, -Y ²¹ - ^OC (= O) -Y ^{22- or -Y 21 -} S (= O) ₂ -O-Y ²² -Medium, Y ²¹ and Y ²² are divalent hydrocarbon groups which may independently have a substituent. The divalent hydrocarbon group is described as a divalent linking group in Ya ^x1 . The same as those mentioned in (divalent hydrocarbon group which may have a substituent) can be mentioned.
As ^Y21 , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is preferable. Especially preferable.
As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkyl methylene group is more preferable. 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.
In the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- , m" is an integer of 0 to 3, preferably an integer of 0 to 2, and 0. Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula- [Y ²¹ -C (= O) -O] _{m "} -Y ^22- is represented by the formula-Y ²¹ -C ⁽ = O) -OY 22-. A group is particularly preferable. Among them, a group represented by the formula- (CH ₂ ) _a' -C (= O) -O- (CH ₂ ) b'-is preferable. In the formula, _a'is 1 to 1 to. It is an integer of 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 and 1 to 8. Is preferred, an integer of 1 to 5 is more preferred, 1 or 2 is even more preferred, and 1 is most preferred.

Among the above, as Ya ^x1 , single bond, ester bond [-C (= O) -O-, -OC (= O)-], ether bond (-O-), linear or branched chain It is preferably a alkylene group in the form of an alkylene group or a combination thereof, and a single bond or an ester bond [-C (= O) -O-, -OC (= O)-] is more preferable.

In the above formula (ahs1), Wa ^x1 is an aromatic hydrocarbon group which may have a substituent.
Examples of the aromatic hydrocarbon group in Wa ^x1 include a group obtained by removing (n _ax1 + 1) hydrogen atoms from an aromatic ring which may have a substituent. 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 a monocyclic type or a polycyclic type. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specifically, the aromatic ring is an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, or phenanthrene; an aromatic heterocycle in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom or the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom and the like. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Further, as the aromatic hydrocarbon group in Wa ^x1 , (n _ax1 + 1) hydrogen atoms are removed from the aromatic compound (for example, biphenyl, fluorene, etc.) containing an aromatic ring which may have two or more substituents. There is also a group.
Among the above, Wa ^x1 is preferably a group obtained by removing (n _ax1 + 1) hydrogen atoms from benzene, naphthalene, anthracene or biphenyl, and a group obtained by removing (n _ax1 + 1) hydrogen atoms from benzene or naphthalene. Is more preferable, and a group obtained by removing (n _ax1 + 1) hydrogen atoms from benzene is even more preferable.

The aromatic hydrocarbon group in Wa ^x1 may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an alkyl halide group and the like. Examples of the alkyl group, alkoxy group, halogen atom, and alkyl halide group as the substituent include those similar to those mentioned as the substituent of the cyclic aliphatic hydrocarbon group in 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, and is an ethyl group or methyl. Groups are more preferred, and methyl groups are particularly preferred. The aromatic hydrocarbon group in Wa ^x1 preferably has no substituent.

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. ..

Hereinafter, a specific example of the structural unit (u1) represented by the above formula (ahs1) will be shown.
In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (u1) contained in the component (P) may be one kind or two or more kinds.
The component (P) may have a structural unit other than the structural unit (u1) represented by the general formula (ahs1).

The component (P) may be a polymer having a repeating structure of one or more kinds of structural units (u1), or a copolymer having a repeating structure of the structural unit (u1) and other structural units. But it may be. Among these, the component (P) is more preferably a polymer having a repeating structure of one kind or two or more kinds of structural units (u1), and a homopolymer having a repeating structure of one kind of structural unit (u1). Homopolymer) is more preferred.

When the component (P) is a copolymer having a repeating structure of the constituent unit (u1) and other constituent units, the ratio of the constituent unit (u1) to the constituent unit (P) constitutes the component (P). With respect to the total of all the constituent units (100 mol%), 50 mol% or more is preferable, 50 to 95 mol% is more preferable, and 60 to 90 mol% is further preferable.
By setting the ratio of the structural unit (u1) to be equal to or higher than the lower limit of the above-mentioned preferable range, it becomes easier to obtain the effect of making the pattern formation less likely to cause undercut.

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 the present embodiment, the content of the component (P) is preferably 1 to 20 parts by mass, preferably 3 to 15 parts by mass, when the total mass part of the component (A) is 100 parts by mass. It is more preferably parts by mass, and even more preferably 5 to 12 parts by mass.
Further, in the photosensitive composition of the present embodiment, the content of the component (P) is 0.5 to 10 parts by mass when the total of the component (A) and the component (P) is 100 parts by mass. It is preferably 1 to 10 parts by mass, more preferably 2 to 10 parts by mass.
When the content of the component (P) is at least the lower limit of the above-mentioned preferable range, it becomes easier to obtain the effect of making the pattern formation less likely to cause undercut. On the other hand, when it is not more than the upper limit of the above-mentioned preferable range, the solubility in the developing solution is maintained, and it becomes easy to obtain a pattern having a good shape.

<Other ingredients>
The photosensitive composition of the present embodiment may contain other components, if necessary, in addition to the above-mentioned components (A), (I) and (P).
To the photosensitive composition of the embodiment, optionally, an additive for improving the performance of a miscible additive such as a metal oxide (M), a silane coupling agent, a sensitizer component, a solvent, and a film. A resin, a dissolution inhibitor, a basic compound, a plasticizer, a stabilizer, a colorant, an antihalation agent and the like can be appropriately added and contained.

≪Metal oxide (M) ≫
In the photosensitive composition of the present embodiment, in addition to the component (A), the component (I) and the component (P), a cured film having increased strength can be easily obtained. Therefore, the metal oxide (M) is further obtained. (Hereinafter, also referred to as "(M) component") may be contained. Further, by having the component (M) together, a high-resolution pattern can be formed with a good shape.
Examples of the component (M) include oxides of metals such as silicon (metal silicon), titanium, zirconium, and hafnium. Among these, an oxide of silicon is preferable, and among these, silica is particularly preferable.

Further, the shape of the component (M) is preferably particulate.
As the particle-like (M) component, those having a volume average particle diameter of 5 to 40 nm are preferable, those having a volume average particle diameter of 5 to 30 nm are more preferable, and those having a volume average particle diameter of 5 to 30 nm are more preferable. A particle group having a particle size of 10 to 20 nm is more preferable.
When the volume average particle size of the component (M) is at least the lower limit of the above-mentioned preferable range, the strength of the cured film is likely to be increased. On the other hand, when it is not more than the upper limit of the above-mentioned preferable range, residue is less likely to be generated in the formation of the pattern, and a pattern having a higher resolution is more likely to be formed. In addition, the transparency of the resin film is enhanced.
The particle size of the component (M) may be appropriately selected according to the exposure light source. Generally, it is said that the influence of light scattering is almost negligible for particles having a particle size of 1/10 or less with respect to the wavelength of light. Therefore, for example, when a fine structure is formed by photolithography with i-line (365 nm), the (M) component is a particle group having a primary particle diameter (volume average value) of 10 to 20 nm (particularly preferably a silica particle group). ) Is preferably used.

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 is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the component (A).
When the content of the component (M) is at least the lower limit of the above-mentioned preferable range, the strength of the cured film is further increased. On the other hand, when it is not more than the upper limit of the above preferable range, the transparency of the resin film is further enhanced.

≪Silane coupling agent≫
The photosensitive composition of the present embodiment may further contain an adhesive aid in order to improve the adhesiveness with the substrate. As the adhesive aid, a silane coupling agent is preferable.
Examples of the silane coupling agent include a silane coupling agent having a reactive substituent such as a carboxy group, a methacryloyl group, an isocyanate group, and an epoxy group. Specific examples include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and β- (3,4-epoxycyclohexyl). Examples thereof include ethyltrimethoxysilane.
One type of silane coupling agent may be used alone, or two or more types may be used in combination.
When the silane coupling agent is contained, the content is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the component (A). It is more preferably 0.1 to 3 parts by mass.
When the content of the silane coupling agent is in the above-mentioned preferable range, the strength of the cured film is further increased. In addition, the adhesiveness between the cured film and the substrate is further strengthened.

≪Sensitizer ingredient≫
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 from exposure and transfer the energy to other substances.
Specific examples of the sensitizer component include benzophenone-based photosensitizers such as benzophenone and p, p'-tetramethyldiaminobenzophenone, carbazole-based photosensitizers, acetphen-based photosensitizers, and 1,5-dihydroxynaphthalene. Naphthalene-based photosensitizers such as, phenol-based photosensitizers, anthracene-based photosensitizers such as 9-ethoxyanthracene, and known photosensitizers such as biacetyl, eosin, rosebengal, pyrene, phenothiazine, and antron. Can be used.
As the sensitizer component, one type may be used alone, or two or more types may be used in combination.
When the sensitizer component is contained, the content is preferably 0.1 to 15 parts by mass, more preferably 0.3 to 10 parts by mass with respect to 100 parts by mass of the component (A). It is more preferably 0.5 to 5 parts by mass.
When the content of the sensitizer component is in the above-mentioned preferable range, the sensitivity and the resolvability are further enhanced.

≪Solvent≫
The photosensitive composition of the present embodiment may further contain a solvent (hereinafter, may be referred to as "component (S)").
Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone and 2-heptanone; ethylene glycol and diethylene glycol. , Polyvalent alcohols such as propylene glycol, dipropylene glycol; 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol. A compound having an ester bond such as monoacetate, a monomethyl ether such as the polyhydric alcohol or the compound having the ester bond, a monoalkyl ether such as monoethyl ether, monopropyl ether, or monobutyl ether, or an ether bond such as monophenyl ether. Derivatives of polyhydric alcohols such as compounds having [Among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferable]; cyclic ethers such as dioxane, methyl lactate, and lactic acid. Esters such as ethyl (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethylbenzyl ether, cresylmethyl ether, diphenyl ether, diphenyl ether, di Examples thereof include aromatic organic solvents such as benzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, simene and mesityrene, and dimethylsulfoxide (DMSO).

As the component (S), one type may be used alone, or two or more types may be used as a mixed solvent.

The amount to be used when the component (S) is contained is not particularly limited, and is appropriately set according to the coating film thickness at a concentration at which the photosensitive composition can be applied to a substrate or the like without dripping.
For example, the component (S) can be used so that the solid content concentration is 50% by mass or more, and the component (S) can be used so that the solid content concentration is 60% by mass or more.
Further, an embodiment in which the component (S) is substantially not contained (that is, an embodiment in which the solid content concentration is 100% by mass) can also be adopted.

Examples of the above-mentioned "additional resin for improving the performance of the film" include compounds represented by the following chemical formula (Add-1).
Examples of commercially available products that can be used as the compound represented by the following chemical formula (Add-1) include TrisP-PA (manufactured by Honshu Chemical Industry Co., Ltd.).

The negative photosensitive resin composition of the present embodiment described above includes an epoxy group-containing compound (A) containing a novolak type epoxy resin, a photocationic polymerization initiator (I) containing an oniumborate salt, and a general formula (ahs1). ) Contains a resin having a structural unit represented by).
Conventionally, a negative photosensitive resin composition containing a novolak type epoxy resin and a photocationic polymerization initiator is excellent in resolution and mechanical properties, but a sulfonium borate salt is used as the photocationic polymerization initiator. In that case, an undercut may occur between the resist cured film of the hollow structure opening and the substrate. Since undercut leads to plating defects after structure formation, a negative photosensitive epoxy resin composition capable of forming a pattern in which undercut does not occur is required.
In the negative photosensitive resin composition of the present embodiment, the epoxy group-containing compound (A) and the photocationic polymerization initiator (I) are further added with a resin having a structural unit represented by the general formula (ahs1). By adding this, it is possible to form a pattern in which undercut is unlikely to occur in pattern formation.

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

Further, according to the negative photosensitive resin composition of the embodiment, a film having a thickness required for a spacer can be formed in the production of a hollow sealing structure, and the shape is good and there is no residue. Resolution patterning is possible.

Further, the negative photosensitive resin composition of the present embodiment can be similarly patterned even when a film is formed of a thick film, and good properties can be obtained. Therefore, the negative photosensitive resin composition of the present embodiment is also useful as a material for a photosensitive resist film.

(Photosensitive resist film)
The photosensitive resist film of the present embodiment is a film in which a photosensitive resin film formed by using the photosensitive composition of the above-described embodiment and a cover film are laminated in this order on a base film.

In the photosensitive resist film of the present embodiment, for example, the photosensitive composition of the above-described embodiment is applied onto a substrate film and dried to form a photosensitive resin film, and then the photosensitive resin film is formed. It can be manufactured by laminating a cover film.
The photosensitive composition may be applied onto the base film by an appropriate method using a blade coater, a lip coater, a comma coater, a film coater or the like.
The thickness of the photosensitive resin film is preferably 100 μm or less, more preferably 5 to 50 μm.

As the base film, a known one can be used, and for example, a thermoplastic resin film or the like is used. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate. The thickness of the base film is preferably 2 to 150 μm.

As the cover film, a known one can be used, and for example, a polyethylene film, a polypropylene film, or the like is used. As the cover film, a film having a smaller adhesive force with the photosensitive resin film than the base film is preferable.
The thickness of the cover film is preferably 2 to 150 μm, more preferably 2 to 100 μm, and even more preferably 5 to 50 μm.
The base film and the cover film may be the same film material, or different film materials may be used.

(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 “film forming step”) and the photosensitive resin film. A step of exposing the sex resin film (hereinafter referred to as “exposure step”) and a step of developing the exposed photosensitive resin film with a developing solution containing an organic solvent to form a negative pattern (hereinafter referred to as “development”). "Process") and.
The pattern forming method of the present embodiment can be performed as follows, for example.

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

The support is not particularly limited, and conventionally known ones can be used, and examples thereof include a substrate for electronic components and a support having a predetermined wiring pattern formed therein. More specifically, it is made of metal such as silicon, silicon nitride, titanium, tantalum, lithium tantalate (LiTaO ₃ ), niobium, lithium niobate (LiNbO ₃ ), palladium, titanium tungsten, copper, chromium, iron and aluminum. Examples include a substrate and a glass substrate.
As the material of the wiring pattern, for example, copper, aluminum, nickel, gold and the like can be used.

The pattern forming method of the present embodiment is a useful method for, for example, a lithium tantalate (LiTaO ₃ ) substrate and a lithium niobate (LiNbO ₃ ) substrate for SAW devices mounted on communication terminals.

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

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

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

The exposure method of the photosensitive resin film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or an immersion exposure (Liquid Immersion Lithology).

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 by using the photosensitive composition of the above-described embodiment has high transparency. Therefore, during exposure in pattern formation, light transmission is increased, and a negative pattern having good lithography characteristics can be easily obtained.
The haze value of the photosensitive resin film after such an exposure step is measured by using a method according to JIS K 7136 (2000).

[Development process]
Next, the photosensitive resin film after the exposure is developed with a developing solution (organic developer) containing an organic solvent. After development, a rinsing treatment is preferably performed. Baking processing (post-baking) may be performed if necessary.

The organic solvent contained in the organic developer may be any one that can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specific examples thereof include ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, polar solvents such as ether solvents, hydrocarbon solvents and the like.

Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, methylcyclohexanone, phenylacetone and methylethylketone. , Methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, γ-butyrolactone, methylamylketone (2-heptanone) and the like. Among these, methylamylketone (2-heptanone) is preferable as the ketone solvent.

Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxy acetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate (PGMEA), ethylene glycol monoethyl ether acetate, and the like. 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 mono Ethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol Monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 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 formic acid, ethyl formic acid, formic acid Butyl, propyl enterrate, 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-ethoxy Examples thereof include propionate and propyl-3-methoxypropionate. Among these, butyl acetate or PGMEA is preferable as the ester solvent.

Examples of the nitrile-based solvent include acetonitrile, propionitril, valeronitrile, butyronitril and the like.

A known additive can be added to the organic developer, if necessary. Examples of the additive include a surfactant. The surfactant is not particularly limited, and for example, an ionic or nonionic fluorine-based and / or silicon-based surfactant can be used.
As the surfactant, a nonionic surfactant is preferable, and a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.% With respect to the total amount of the organic developer. 5% by mass is more preferable.

The developing process can be carried out by a known developing method. For example, a method of immersing a support in a developing solution for a certain period of time (dip method), or a method in which a developing solution is raised on the surface of a support by surface tension for a certain period of time. A method of standing still (paddle method), a method of spraying the developer on the surface of the support (spray method), a method of applying the developer on the support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed. Examples include a method of continuously producing (dynamic dispense method).

The rinsing treatment (cleaning treatment) using the rinsing liquid can be carried out by a known rinsing method. As the method of the rinsing treatment, for example, a method of continuously spraying the rinsing liquid on the support rotating at a constant speed (rotary coating method), a method of immersing the support in the rinsing liquid for a certain period of time (dip method), and the like. Examples thereof include a method of spraying a rinse liquid on the surface of the support (spray method).
For the rinsing treatment, it is preferable to use a rinsing liquid containing an organic solvent.

A pattern can be formed by the film forming step, the exposure step and the developing step described above.

In the pattern forming method of the above-described embodiment, since the negative photosensitive resin composition according to the above-mentioned aspect is used, it is possible to form a pattern in which the occurrence of undercut is suppressed in the pattern formation. ..

(Hardened film)
The cured film of the present embodiment is a cured negative-type photosensitive resin composition of the above-mentioned embodiment.

(Manufacturing method of cured film)
The method for producing a cured film of the present embodiment includes the step (i) of forming a photosensitive resin film on a support using the negative photosensitive resin composition of the above-described embodiment, and the step (i) of forming the photosensitive resin film. It has a step (ii) of curing to obtain a cured film.
The operation of the step (i) can be performed in the same manner as the above-mentioned [film forming step]. The baking treatment can be performed, for example, under the temperature condition of 80 to 150 ° C. for 40 to 600 seconds.
The curing treatment in the step (ii) can be performed under the conditions of, for example, a temperature of 100 to 250 ° C. and 0.5 to 2 hours.

The method for producing the cured film of the embodiment may include other steps in addition to the step (i) and the step (ii). For example, the above-mentioned [exposure step] may be provided between the step (i) and the step (ii), and the photosensitive resin film formed in the step (i) is selectively exposed. If necessary, the photosensitive resin film (pre-cured film) subjected to the bake (PEB) treatment can be cured to obtain a cured film.
According to the method for producing a cured film according to the above-described embodiment, the occurrence of undercut is suppressed, and a cured film that faithfully reproduces the mask pattern can be easily produced.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

<Preparation of negative 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, filtered using a PTFE filter (pore diameter 1 μm, manufactured by PALL Corporation), and the negative photosensitive resin composition of each example was obtained. (Solutions with a solid content of 60 to 65% by mass) were prepared respectively.

In Table 1 and Table 2, each abbreviation has the following meaning. The numerical value in [] is the blending amount (part by mass; solid content conversion) of each component.
(A1) -1: Novolac type epoxy resin represented by the following chemical formula (A1-1). Product name "jER-157S70", manufactured by Mitsubishi Chemical Corporation.

(A2) -1: Solid bisphenol type epoxy resin represented by the following chemical formula (A2-1). Product name "EPICLON1055", manufactured by DIC Corporation.
(A3) -1: An epoxy group-containing compound represented by the following chemical formula (A3-1). Product name "TEPIC-VL", manufactured by Nissan Chemical Industries, Ltd.

(P) -1: Polyhydroxystyrene having a repeating structure of a structural unit represented by the following chemical formula (P-1). Product name "VP-8000", manufactured by Nippon Soda Corporation. The weight average molecular weight (Mw) in terms of standard polystyrene obtained by GPC measurement is 8000, and the molecular weight dispersion (Mw / Mn) is 1.1.

(I1) -1: Photocationic polymerization initiator represented by the following chemical formula (I1-5).

(I2) -1: Photocationic polymerization initiator represented by the following chemical formula (I2-1-2).
(I3) -1: Photocationic polymerization initiator represented by the following chemical formula (I3-1-1).

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

<Pattern formation>
Membrane formation process:
The negative photosensitive resin compositions of each example were applied onto a silicon substrate using a spinner, prebaked (PAB) at a temperature of 115 ° C. for 5 minutes on a hot plate, and dried. A photosensitive resin film having a thickness of 20 μm was formed.

Exposure process:
Next, the photosensitive resin film was irradiated with ghi rays with a gap of 30 μm.
Then, on a hot plate at 90 ° C., heating was performed after exposure for 5 minutes.

Development process:
Next, development was carried out for 120 seconds using propylene glycol monomethyl ether acetate (PGMEA) to attempt to form a negative pattern. As a result, a hole pattern having a diameter of 60 μm was formed.

[Evaluation of Optimal Exposure (Eop)]
The optimum exposure amount Eop (mJ / cm ² ) at which a hole pattern of the target size is formed was obtained by the above <pattern formation>. This is shown in Tables 3 and 4 as "Eop (mJ / cm ² )".

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

The table shown in FIG. 1 shows the evaluation criteria of undercut.
The photograph in the table is a cross section of the hole pattern formed by the above <pattern formation> observed with the scanning electron microscope. Reference numeral 10 is a silicon substrate, reference numeral 20 is a residual film portion, and reference numeral 30 is a hole portion.
The undercut evaluation is set to C, B, and A according to the notched state of the region surrounded by the circle, 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 A, it means that the occurrence of undercut is suppressed more sufficiently.

From the results shown in Table 3, it can be confirmed that the occurrence of undercut is suppressed in the pattern formed by using the negative photosensitive resin compositions of Examples 1 and 2 to which the present invention is applied.

Undercut occurred in the pattern formed by using the negative photosensitive resin composition of Comparative Example 1 containing an onium borate salt as a photocationic polymerization initiator.
On the other hand, in the pattern formed by using the negative photosensitive resin composition of Reference Example 1 in which the anion portion contains an onium salt which is a phosphorus-based anion as the photocationic polymerization initiator, the occurrence of undercut is suppressed. rice field.
From these results, it can be confirmed that the undercut generated during pattern formation is peculiar when the onium borate salt is used as the photocationic polymerization initiator.

From the results shown in Table 4, in the pattern formed by using the negative photosensitive resin compositions of Examples 3 to 7, which further contain the component (A3) in addition to the components (A1) and (A2), It can be confirmed that the occurrence of undercut is suppressed more sufficiently.

10 Silicon substrate, 20 Remaining film part, 30 hole part

Claims (9)

Epoxy group-containing compound (A) and
Photocationic polymerization initiator (I) and
A resin having a structural unit represented by the following general formula (ahs1) and
Contains,
The epoxy group-containing compound (A) contains a novolak type epoxy resin and contains.
The photocationic polymerization initiator (I) is a negative photosensitive resin composition containing an onium borate salt.

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or divalent linking group. Wa ^x1 is an aromatic hydrocarbon group which may have a substituent. n _ax1 is an integer of 1 or more. ] The negative photosensitive resin composition according to claim 1, wherein the onium borate salt is a compound represented by the following general formula (I1).

[In the formula, R ^b01 to R ^b04 are aryl groups or fluorine atoms which may independently have a substituent. q is an integer of 1 or more, and Q ^{q +} is a q-valent organic cation. ] The negative photosensitive resin composition according to claim 1 or 2, wherein the novolak type epoxy resin is an epoxy resin represented by the following general formula (anv0).

[In the formula, R ^p1 and R ^p2 are independently alkyl groups having 1 to 5 hydrogen atoms or 1 to 5 carbon atoms. The plurality of R ^p1s may be the same as or different from each other. The plurality of R ^p2s may be the same as or different from each other. n ₁ is an integer of 1 to 5. R ^EP is an epoxy group-containing group. The plurality of R ^EPs may be the same as or different from each other. ] The negative 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. 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).

[In the formula, R ^EP is an epoxy group-containing group. The plurality of R ^EPs may be the same as or different from each other. R ^a31 and R ^a32 are independently hydrogen atoms, alkyl groups having 1 to 5 carbon atoms, or fluorinated alkyl groups having 1 to 5 carbon atoms. na ³¹ is an integer from 1 to 50. ] The content of the resin having the structural unit represented by the general formula (ahs1) is 100 mass by mass of the total of the epoxy group-containing compound (A) and the resin having the structural unit represented by the general formula (ahs1). The negative photosensitive resin composition according to any one of claims 1 to 5, wherein the portion is 0.5 to 10 parts by mass. The negative photosensitive resin composition according to any one of claims 1 to 6, wherein the epoxy group-containing compound (A) further contains a compound represented by the following general formula (ta1).

[In the formula, R ^EP is an epoxy group-containing group. The plurality of R ^EPs may be the same as or different from each other. ] 7. The content of the compound represented by the general formula (ta1) is 0.1 to 10 parts by mass when the total mass part of the epoxy group-containing compound (A) is 100 parts by mass. The negative type photosensitive resin composition according to. A step of forming a photosensitive resin film on a support by using the negative photosensitive resin composition according to any one of claims 1 to 8.
The step of exposing the photosensitive resin film and
A step of developing the photosensitive resin film after exposure with a developing solution containing an organic solvent to form a negative pattern.
A pattern forming method.

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