JP7700536B2 - Negative Photosensitive Polymer - Google Patents

Description

The present invention relates to a negative-type photosensitive polymer.

Polyimide resins have high mechanical strength, heat resistance, insulating properties, and solvent resistance, and are therefore widely used as protective materials in liquid crystal display elements and semiconductors, insulating materials, and thin films for electronic materials such as color filters.

Patent Document 1 discloses a liquid crystal aligning agent that contains at least one polymer selected from the group consisting of polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine and polyimide obtained by dehydrating and ring-closing the polyamic acid. The document lists 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine (hereinafter also referred to as TMDA) as the diamine.

Patent Document 2 discloses a polyimide polymer that contains a reaction product of a diamine, a tetracarboxylic dianhydride, and a compound having a specific functional group. The document lists TMDA as the diamine.

Patent document 3 discloses a dry film structure including a carrier substrate and a photosensitive polymer layer including a fully imidized polyimide polymer. The document lists TMDA as a diamine that constitutes the fully imidized polyimide polymer.

Patent Document 4 discloses a photosensitive composition that contains a fully imidized polyimide polymer, a solubility-switching compound, a photoinitiator, and a solvent, and that can form a film that exhibits a predetermined dissolution rate. This document lists TMDA as a diamine that constitutes the fully imidized polyimide polymer.

Patent Document 5 discloses a photosensitive resin composition that contains a polyimide resin having a specific structure and a weight average molecular weight of 70,000 or less. The document also describes that at least one of the terminals of the polyimide resin is a group that contains a (meth)acrylate group.

JP 2011-257736 A JP 2017-513959 A JP 2018-517168 A JP 2018-517169 A International Publication No. 2020/246349

However, in the conventional techniques described in Patent Documents 1 to 5, there was room for improvement in the mechanical strength of the films containing polyimide obtained from the photosensitive resin composition.

Conventionally, fluorine atoms have been introduced into the skeleton of a polyimide in order to improve the solubility of the polyimide in an organic solvent. However, the present inventors have found that when a polyimide is synthesized using a diamine compound containing a fluorine atom, the strong electron-withdrawing property of the fluorine atom affects the electrons of the imide ring, making the resulting polyimide more susceptible to hydrolysis, and thus reducing the mechanical strength.
That is, conventional polyimides have room for improvement in terms of the balance between solubility in organic solvents and mechanical strength.

The present inventors have found that the above problems can be solved by using a polyimide having a specific structure, and have completed the present invention.
That is, the present invention can be shown as follows.

（一般式（ａ１）中、Ｙは２価の有機基である。
一般式（ａ２）中、Ｒ^１、Ｒ^２は、それぞれ独立して、水素原子、炭素数１～３のアルキル基または炭素数１～３のアルコキシ基を示す。複数存在するＲ^１同士、複数存在するＲ^２同士は同一でも異なっていてもよい。
一般式（ａ３）中、Ｑは、２価～４価の炭素数１～１０の有機基を示し、複数存在するＱは同一でも異なっていてもよい。
Ｒ^５およびＲ^６は、それぞれ独立して、水素原子、炭素数１～３のアルキル基、炭素数１～３のアルコキシ基を示す。
ｍ１およびｍ２は、それぞれ独立して１～３の整数を示す。
Ｘは単結合、－ＳＯ_２－、－Ｃ（＝Ｏ）－、または炭素数１～５の直鎖または分岐のアルキレン基を示し、複数存在するＸは同一でも異なっていてもよい。） According to the present invention,
A structural unit (a1) represented by the following general formula (a1),
A structural unit (a2) represented by the following general formula (a2):
A structural unit (a3) represented by the following general formula (a3):
A negative-acting photosensitive polymer is provided, comprising:

(In general formula (a1), Y is a divalent organic group.
In general formula (a2), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. A plurality of R ^1s and a plurality of R ^2s may be the same or different.
In formula (a3), Q represents a divalent to tetravalent organic group having 1 to 10 carbon atoms, and a plurality of Q's may be the same or different.
^R5 and ^R6 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.
m1 and m2 each independently represent an integer of 1 to 3.
X represents a single bond, -SO ₂ -, -C(=O)-, or a linear or branched alkylene group having 1 to 5 carbon atoms, and multiple X's may be the same or different.

The present invention provides a negative-type photosensitive polymer that has excellent solubility in organic solvents, is inhibited from hydrolysis, and can give a cured product such as a film with excellent mechanical strength.

1 is a schematic cross-sectional view of a semiconductor device according to an embodiment of the present invention;

The following describes an embodiment of the present invention with reference to the drawings. In all drawings, similar components are given similar reference symbols and descriptions are omitted where appropriate. In addition, "A-B" indicates "A or more" to "B or less" unless otherwise specified.

The negative photosensitive polymer of this embodiment contains a structural unit (a1) represented by the following general formula (a1), a structural unit (a2) represented by the following general formula (a2), and a structural unit (a3) represented by the following general formula (a3).

In formula (a1), Y is a divalent organic group.
As the divalent organic group, a known organic group can be used as long as the effects of the present invention are achieved. From the viewpoint of the effects of the present invention, however, a divalent organic group selected from the following general formula (a1-1), the following general formula (a1-2), and the following general formula (a1-3) is preferred.

In general formula (a1-1), R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and a plurality of R ^7s and a plurality of R ^8s may be the same or different.
From the viewpoint of the effects of the present invention, R ⁷ and R ⁸ are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom.
R ⁹ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and a plurality of R ^9s may be the same or different.
From the viewpoint of the effects of the present invention, R ⁹ is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom.
* indicates a bond.

In general formula (a1-2), R ¹⁰ and R ¹¹ each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and a plurality of R ^10s and a plurality of R ^11s may be the same or different.

From the viewpoint of the effects of the present invention, R ¹⁰ and R ¹¹ are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably at least one of R ¹⁰ and at least one of R ¹¹ are an alkyl group having 1 to 3 carbon atoms, even more preferably three of R ¹⁰ are alkyl groups having 1 to 3 carbon atoms, one of R ¹⁰ is a hydrogen atom, and three of R ¹¹ are alkyl groups having 1 to 3 carbon atoms, and one of R ¹¹ is a hydrogen atom, particularly preferably three of R ¹⁰ are methyl groups, one of R ¹⁰ is a hydrogen atom, and three of R ¹¹ are methyl groups, and one of R ¹¹ is a hydrogen atom.
* indicates a bond.

In general formula (a1-3), Z represents an alkylene group having 1 to 5 carbon atoms or a divalent aromatic group.
* indicates a bond.

In general formula (a2), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. A plurality of R ^1s and a plurality of R ^2s may be the same or different.
From the viewpoint of the effects of the present invention, R ¹ and R ² are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom.

By containing the structural unit represented by general formula (a2), the polyimide (A) of this embodiment suppresses the effect on the electrons of the imide ring, suppressing hydrolysis of the polyimide, and providing excellent mechanical strength and solubility in organic solvents. In other words, the polyimide (A) of this embodiment and the negative photosensitive resin composition containing polyimide (A) have an excellent balance of these properties.

In general formula (a3), Q represents a divalent to tetravalent organic group having 1 to 10 carbon atoms, and multiple Qs may be the same or different.

Examples of the divalent to tetravalent organic group having 1 to 10 carbon atoms include an ester group, a divalent to tetravalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and a divalent to tetravalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. These hydrocarbon groups may contain a heteroatom such as oxygen, nitrogen, or sulfur atom, and may have an ester bond, a thioester bond, a urethane bond, a thiourethane bond, or the like in the structure.
^R5 and ^R6 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.
m1 and m2 each independently represent an integer of 1 to 3.

X represents a single bond, --SO ₂ --, --C(.dbd.O)--, a linear or branched alkylene group having 1 to 5 carbon atoms, or a linear or branched fluoroalkylene group having 1 to 5 carbon atoms, and multiple X's may be the same or different.

From the viewpoint of the effects of the present invention, X is preferably a linear or branched alkylene group having 1 to 5 carbon atoms, or a linear or branched fluoroalkylene group having 1 to 5 carbon atoms.
Specifically, the polyimide (A) of the present embodiment can contain a structural unit represented by the following general formula (1).

In formula (1), R ¹ and R ² have the same meanings as in formula (a2), and Y has the same meaning as in formula (a1).
Specifically, the polyimide (A) of the present embodiment can contain a structural unit represented by the following general formula (2) in addition to the structural unit represented by the above general formula (1).

In formula (2), Q, R ⁵ , R ⁶ , m1, m2 and X are defined as in formula (a3), and Y is defined as in formula (a1).
Specifically, the polyimide (A) of the present embodiment can contain a structural unit represented by the above general formula (3).

In formula (3), Q, R ⁵ , R ⁶ , m1, m2 and X are defined as in formula (a3), Y is defined as in formula (a1), and R ¹ and R ² are defined as in formula (a2).
The polyimide (A) of the present embodiment contains the above structural units and may further contain the following structural units in part.

In the present embodiment, it is preferable that at least one of the two ends of the polyimide (A) is a (meth)acrylate group. By including such a group, hydrolysis is suppressed and the mechanical strength is superior.
The weight average molecular weight of the polyimide (A) of the present embodiment is 5,000 to 200,000, and preferably 10,000 to 100,000.

The polyimide (A) (negative photosensitive polymer) of the present embodiment has excellent hydrolysis resistance, and the rate of decrease in weight average molecular weight measured under the following conditions is 15% or less, preferably 12% or less, more preferably 10% or less, and particularly preferably 5% or less.
(conditions)
The viscosity is calculated according to the following formula when 400 parts by mass of γ-butyrolactone, 200 parts by mass of 4-methyltetrahydropyran, and 50 parts by mass of water are added to 100 parts by mass of the negative photosensitive polymer and stirred at 100° C. for 6 hours.
Formula: [(weight average molecular weight before test−weight average molecular weight after test)/weight average molecular weight before test]×100

The negative photosensitive polymer of this embodiment has a weight average molecular weight reduction rate within the above range, making it possible to obtain a cured product such as a film that has excellent mechanical strength, such as elongation.

In addition, since the polyimide (A) of this embodiment has excellent solubility in solvents and does not need to be made into a varnish in the precursor state, a varnish containing the polyimide (A) can be prepared, and a cured product such as a film can be obtained from the varnish.

<Method for producing polyimide (A)>
The method for producing a polyimide (A) (negative type photosensitive polymer) having a structural unit represented by general formula (1) and a structural unit represented by general formula (2) or a polyimide (A) (negative type photosensitive polymer) having a structural unit represented by general formula (3) of the present embodiment includes the steps of:

Step 1 involves imidizing an acid anhydride (a1') represented by the following general formula (a1'), a diamine (a2') represented by the following general formula (a2'), and a bisaminophenol (a3') represented by the following general formula (a3') at a temperature of 100°C or higher and 250°C or lower;

Step 2 of reacting a compound having a (meth)acrylate group with a hydroxyl group of a structural unit derived from the bisaminophenol (a3′) of the general formula (a3′) of the polymer obtained in Step 1 to introduce a group containing a (meth)acrylate group;
Includes.
According to this embodiment, a polyimide (A) having excellent solubility in organic solvents can be synthesized by a simple method.

In general formula (a1'), Y is selected from the groups represented by general formula (a1-1), (a1-2) or (a1-3).

In formula (a2'), R ¹ and R ² have the same meanings as in formula (a2).

In formula (a3'), X has the same meaning as in formula (a3).
In order to control the molecular weight of the resulting polyhydroxyimide, it is also possible to carry out the reaction by adding a small amount of an acid anhydride or aromatic amine as an end-capping agent.

Examples of acid anhydrides that serve as end-capping agents include phthalic anhydride, maleic anhydride, and nadic anhydride, while examples of aromatic amines include p-methylaniline, p-methoxyaniline, and p-phenoxyaniline. The amount of acid anhydrides or aromatic amines added that serve as end-capping agents is preferably 5 mol% or less. If the amount exceeds 5 mol%, the molecular weight of the resulting polyhydroxyimide will decrease significantly, causing problems with heat resistance and mechanical properties.

The equivalent ratio of the acid anhydride (a1'), diamine (a2') and bisaminophenol (a3') in the imidization reaction in step 1 is an important factor that determines the molecular weight of the resulting polymer. It is generally well known that there is a correlation between the molecular weight and mechanical properties of a polymer, and the higher the molecular weight, the better the mechanical properties. Therefore, in order to obtain a polymer with practically excellent strength, a certain degree of high molecular weight is necessary. In the present invention, the equivalent ratio of the acid anhydride (a1'), diamine (a2') and bisaminophenol (a3') used is not particularly limited, but it is preferable that the equivalent ratio of the diamine (a2') and bisaminophenol (a3') to the acid anhydride (a1') is in the range of 0.70 to 1.3. If the equivalent ratio is within the above range, the mechanical strength and production stability are excellent.

From the viewpoint of improving mechanical properties, even if the equivalent ratio of the diamine (a2') and the bisaminophenol (a3') to the acid anhydride (a1') is outside the above range, the apparent molecular weight can be increased by crosslinking the resin through side chains.
Step 1 (imidization reaction step) can be carried out in an organic solvent by a known method.

Examples of organic solvents include aprotic polar solvents such as γ-butyrolactone (GBL), N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, cyclohexanone, and 1,4-dioxane. One or more of these may be used in combination. In this case, a nonpolar solvent that is compatible with the above aprotic polar solvent may be mixed and used. Examples of nonpolar solvents include aromatic hydrocarbons such as toluene, ethylbenzene, xylene, mesitylene, and solvent naphtha, and ether solvents such as cyclopentyl methyl ether. The ratio of the nonpolar solvent in the mixed solvent can be set arbitrarily depending on the resin properties such as the stirring device capacity and solution viscosity, as long as the solubility of the solvent is reduced and the polyamic acid resin obtained by the reaction is not precipitated.

The reaction temperature is 0°C to 100°C, preferably 20°C to 80°C, for 30 minutes to 2 hours, and then 100°C to 250°C, preferably 120°C to 200°C, for 1 to 5 hours.

By step 1, it is possible to obtain a polyhydroxyimide having a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2'), or a polyhydroxyimide containing a structural unit having a structural unit represented by the following general formula (3'). In step 1, the polyhydroxyimide can be purified by a known method, but it is also possible to improve the dehydration efficiency in the polymerization and perform steps 1 and 2 consecutively without purifying the obtained polyhydroxyimide.

In step 2, a compound having a (meth)acrylate group is reacted with the hydroxyl group of the polyhydroxyimide obtained in step 1 to introduce a crosslinking group containing a (meth)acrylate group.
The crosslinking groups introduced into the polyimide (A) react with the crosslinking agent (B) described below in the exposure step, making the exposed areas insoluble in organic solvents.

Examples of compounds containing a (meth)acrylate group include 2-isocyanatoethyl (meth)acrylate, 2-(2-(meth)acryloyloxyethyloxy)ethyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate, glycidyl methacrylate, and 4-hydroxybutyl acrylate glycidyl ether.

To introduce a crosslinking group containing a (meth)acrylate group into polyhydroxyimide, polyhydroxyimide and a compound containing a (meth)acrylate group are mixed in an organic solvent and reacted at 60°C to 150°C for about 2 to 10 hours. The reaction can be carried out at normal pressure, although there are no particular limitations.

The compound having a (meth)acrylate group can be appropriately selected according to the amount of crosslinking groups to be introduced into the polyhydroxyimide. For example, it can be added in an amount of 0.8 to 3.0 times the molar amount of hydroxyl groups in the polyhydroxyimide, and preferably 2.0 to 3.0 times the molar amount. If the polyhydroxyimide has a group capable of introducing a crosslinking group, the group can be added to the molar amount.

Examples of the organic solvent include aprotic polar solvents such as γ-butyrolactone (GBL), N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, cyclohexanone, and 1,4-dioxane, and these may be used alone or in combination of two or more. In this case, a nonpolar solvent that is compatible with the above aprotic polar solvent may be mixed and used. Examples of the nonpolar solvent include aromatic hydrocarbons such as toluene, ethylbenzene, xylene, mesitylene, and solvent naphtha, and ether solvents such as cyclopentyl methyl ether.
In the reaction, a base such as triethylamine or 1,1,3,3-tetramethylguanidine can be added.

By step 2, a polyimide (A) having a structural unit represented by general formula (1) and a structural unit represented by general formula (2), or a polyimide (A) having a structural unit represented by general formula (3) can be obtained.

In step 2, the reaction solution containing the polyhydroxyimide obtained in step 1 can be purified by reprecipitation or the like to obtain polyhydroxyimide, but the reaction solution in step 1 can be used as is in step 2.

By the manufacturing method of this embodiment described above, a reaction solution containing the polyimide (A) (negative photosensitive polymer) of this embodiment can be obtained, which can be further diluted with an organic solvent or the like as necessary and used as a polymer solution (varnish for application). As the organic solvent, those exemplified in the reaction process can be used, and may be the same organic solvent as in the reaction process or a different organic solvent.

Also, this reaction solution can be poured into a poor solvent to reprecipitate the polyimide (A) resin, remove unreacted monomers, and then dry and solidify it, which can then be dissolved again in an organic solvent and used as a refined product. In particular, in applications where impurities and foreign matter are a problem, it is preferable to dissolve it again in an organic solvent and filter it to produce a refined varnish.

<Negative Photosensitive Resin Composition>
In this embodiment, the negative photosensitive resin composition may contain the above-mentioned negative photosensitive polymer. The negative photosensitive resin composition of this embodiment is not particularly limited as long as it contains a negative photosensitive polymer and has negative photosensitivity, but preferably contains, for example, a negative photosensitive polymer (polyimide (A)), a crosslinking agent (B) containing a polyfunctional (meth)acrylate, and a photopolymerization initiator (C).

[Crosslinking agent (B)]
The crosslinking agent (B) contains a polyfunctional (meth)acrylate.
The polyfunctional (meth)acrylate is a compound having two or more (meth)acryloyl groups, and any conventionally known compound can be used as long as it can exert the effects of the present invention. In this embodiment, the (meth)acrylic group refers to an acrylic group or a methacrylic group.

Specific examples of polyfunctional (meth)acrylates include difunctional (meth)acrylates such as diethylene glycol di(meth)acrylate, polyethylene glycol #200 di(meth)acrylate, and polyethylene glycol #400 di(meth)acrylate; trifunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and ethoxylated isocyanuric acid triacrylate; tetrafunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate and ditrimethylolpropane tetra(meth)acrylate; hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate; octafunctional (meth)acrylates such as tripentaerythritol octa(meth)acrylate; and decafunctional (meth)acrylates such as tetrapentaerythritol deca(meth)acrylate. One or more of these may be used.

From the viewpoint of the effects of the present invention, the amount of crosslinking agent (B) per 100 parts by mass of polyimide (A) can be set to 1 part by mass or more and 30 parts by mass or less, preferably 2 parts by mass or more and 20 parts by mass or less, and preferably 3 parts by mass or more and 15 parts by mass or less. By being in this range, elongation is further improved.

[Photopolymerization initiator (C)]
As the photopolymerization initiator (C), for example, a photoradical generator can be used. The photoradical generator contains a photoradical generator that generates radicals when irradiated with active light such as ultraviolet light and functions as a photopolymerization initiator for the polyimide (A) described above.

Examples of the photoradical generator include an alkylphenone type initiator, an oxime ester type initiator, and an acylphosphine oxide type initiator. For example, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, bis(2,4,6-trimethylphenyl)propan-1-one, and bis(2,4,6-trimethylphenyl)propan-1-one. 1-[4-(phenylthio)-, 2-(O-benzoyloxime)), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), 2-(dimethylamino)-1-(4-(4-morpholino)phenyl)-2-(phenylmethyl)-1-butanone, Irgacure Examples of the compound include Oxe01 (BASF Japan Ltd.), Irgacure Oxe02 (BASF Japan Ltd.), Irgacure Oxe03 (BASF Japan Ltd.), Irgacure Oxe04 (BASF Japan Ltd.), N-1919T (ADEKA Corporation), NCI-730 (ADEKA Corporation), NCI-831E (ADEKA Corporation), NCI-930 (ADEKA Corporation), etc. Any one or more of these may be used.
Among these, from the viewpoint of the effects of the present invention and further from the viewpoint of producing a resin film composed of a photosensitive resin composition having superior exposure sensitivity, oxime ester-type initiators are preferred.

The amount of polymerization initiator (C) added is not particularly limited, but is preferably about 0.3 to 20 mass% of 100 mass% of the non-volatile components excluding the solvent of the negative photosensitive resin composition, more preferably about 0.5 to 15 mass%, and even more preferably about 1 to 10 mass%. By setting the amount of polymerization initiator (C) added within the above range, it is possible to improve the patterning properties of the photosensitive resin layer containing the negative photosensitive resin composition and to improve the long-term storage properties of the negative photosensitive resin composition.

(solvent)
The negative photosensitive resin composition according to this embodiment may contain a solvent, which allows a uniform photosensitive resin film to be formed on the surface of various substrates.

As the solvent, an organic solvent is preferably used. Specifically, one or more of ketone-based solvents, ester-based solvents, ether-based solvents, alcohol-based solvents, lactone-based solvents, carbonate-based solvents, etc. can be used.

Examples of solvents include propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, methyl isobutyl carbinol (MIBC), gamma butyrolactone (GBL), N-methylpyrrolidone (NMP), methyl-n-amyl ketone (MAK), diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, cyclohexanone, or mixtures thereof.
The amount of the solvent used is not particularly limited, but is used in an amount such that the concentration of non-volatile components becomes, for example, 10 to 70% by mass, and preferably 15 to 60% by mass.

(Surfactant)
The negative photosensitive resin composition according to this embodiment may further contain a surfactant.
The surfactant is not limited, and specific examples thereof include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; EFTOP EF301, EFTOP EF303, EFTOP EF352 (manufactured by Shin-Akita Chemical Industry Co., Ltd.), Megafack F171, Megafack F172, Megafack F173, Megafack F177, and Megafack F444. Fluorine-based surfactants commercially available under the names of MEGAFAC F470, MEGAFAC F471, MEGAFAC F475, MEGAFAC F482, MEGAFAC F477 (manufactured by DIC Corporation), FLORADO FC-430, FLORADO FC-431, NOVEC FC4430, NOVEC FC4432 (manufactured by 3M Japan Ltd.), SURFLOON S-381, SURFLOON S-382, SURFLOON S-383, SURFLOON S-393, SURFLOON SC-101, SURFLOON SC-102, SURFLOON SC-103, SURFLOON SC-104, SURFLOON SC-105, SURFLOON SC-106, (manufactured by AGC Seimi Chemical Co., Ltd.); organosiloxane copolymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); (meth)acrylic acid copolymer Polyflow No. 57, 95 (manufactured by Kyoeisha Chemical Co., Ltd.), etc.

Among these, it is preferable to use a fluorosurfactant having a perfluoroalkyl group. As the fluorosurfactant having a perfluoroalkyl group, it is preferable to use one or more selected from the above specific examples: Megafac F171, Megafac F173, Megafac F444, Megafac F470, Megafac F471, Megafac F475, Megafac F482, Megafac F477 (manufactured by DIC Corporation), Surflon S-381, Surflon S-383, Surflon S-393 (manufactured by AGC Seimi Chemical Co., Ltd.), Novec FC4430, and Novec FC4432 (manufactured by 3M Japan Ltd.).

As the surfactant, silicone surfactants (such as polyether-modified dimethylsiloxane) can also be preferably used. Specific examples of silicone surfactants include the SH series, SD series, and ST series from Dow Corning Toray Co., Ltd., the BYK series from BYK Japan Co., Ltd., the KP series from Shin-Etsu Chemical Co., Ltd., the Disform (registered trademark) series from NOF Corporation, and the TSF series from Toshiba Silicones Co., Ltd.

The upper limit of the surfactant content in the negative photosensitive resin composition is preferably 1% by mass (10,000 ppm) or less, more preferably 0.5% by mass (5,000 ppm) or less, and even more preferably 0.1% by mass (1,000 ppm) or less, based on the total amount of the negative photosensitive resin composition (including the solvent).

There is no particular lower limit for the content of the surfactant in the negative photosensitive resin composition. From the viewpoint of obtaining a sufficient effect of the surfactant, the content is, for example, 0.001 mass % (10 ppm) or more with respect to the entire negative photosensitive resin composition (including the solvent).
By appropriately adjusting the amount of the surfactant, it is possible to improve the coatability and the uniformity of the coating film while maintaining other performance properties.

(Antioxidants)
The negative photosensitive resin composition according to this embodiment may further contain an antioxidant. As the antioxidant, one or more selected from a phenol-based antioxidant, a phosphorus-based antioxidant, and a thioether-based antioxidant can be used. The antioxidant can suppress oxidation of the resin film formed from the negative photosensitive resin composition.

Phenol-based antioxidants include pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}2,4,8,10-tetraoxaspiro[5,5]undecane, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,6-hexanediol-bis[3-(3,5-di-t- butyl-4-hydroxyphenyl)propionate], 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl(3,5-di-t-butyl-4-hydroxyphenyl)propionate, distearyl(3,5-di-t-butyl-4-hydroxybenzyl)phosphonate, thiodiethylene ethylene glycol bis[(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 4,4'-thiobis(6-t-butyl-m-cresol), 2-octylthio-4,6-di(3,5-di-t-butyl-4-hydroxyphenoxy)-s-triazine, 2,2'-methylenebis(4-methyl-6-t-butyl-6-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), bis[3,3-bis(4-hydroxy-3-t-butylphenyl)butyric acid cid] glycol ester, 4,4'-butylidenebis(6-t-butyl-m-cresol), 2,2'-ethylidenebis(4,6-di-t-butylphenol), 2,2'-ethylidenebis(4-s-butyl-6-t-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, bis[2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenyl]terephthalate, 1,3,5-tris(2,6-dimethyl- 3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,3,5-tris[(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, 2-t-butyl-4-methyl-6-(2-acryloyloxy-3-t-butyl-5-methyl 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4-8,10-tetraoxaspiro[5,5]undecane-bis[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], triethylene glycol bis[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], 1,1'-bis(4-hydroxyphenyl)cyclohexane, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methyl 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 2,2'-methylenebis(6-(1-methylcyclohexyl)-4-methylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis(2-(3-t-butyl-4-hydroxy-5-methylphenylpropionyloxy)1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-bis(3,5- Di-t-butyl-4-hydroxybenzyl) sulfide, 4,4'-thiobis(6-t-butyl-2-methylphenol), 2,5-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylate, 2,4-dimethyl-6-(1-methylcyclohexyl, styrenated phenol, 2,4-bis((octylthio)methyl)-5-methylphenol, etc.

Phosphorus-based antioxidants include bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl phosphite), tetrakis(2,4-di-t-butyl-5-methylphenyl)-4,4'-biphenylene diphosphonite, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, bis-(2,6-dicumylphenyl)pentaerythritol diphosphite, 2,2-methylene biphosphonate, Examples include bis(4,6-di-t-butylphenyl)octyl phosphite, tris(mixed mono- and di-nonylphenyl phosphite), bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methoxycarbonylethyl-phenyl)pentaerythritol diphosphite, and bis(2,6-di-t-butyl-4-octadecyloxycarbonylethylphenyl)pentaerythritol diphosphite.

Examples of thioether antioxidants include dilauryl-3,3'-thiodipropionate, bis(2-methyl-4-(3-n-dodecyl)thiopropionyloxy)-5-t-butylphenyl)sulfide, distearyl-3,3'-thiodipropionate, and pentaerythritol-tetrakis(3-lauryl)thiopropionate.

(Adhesion aid)
The negative photosensitive resin composition according to this embodiment may further contain an adhesion assistant.
As the adhesion aid, for example, a silane coupling agent such as aminosilane, epoxysilane, (meth)acrylicsilane, mercaptosilane, vinylsilane, ureidosilane, acid anhydride functional silane, sulfidesilane, etc. can be used. The silane coupling agent may be used alone or in combination of two or more. Among these, epoxysilane (i.e., a compound containing both an epoxy moiety and a group that generates a silanol group by hydrolysis in one molecule) or acid anhydride functional silane (i.e., a compound containing both an acid anhydride group and a group that generates a silanol group by hydrolysis in one molecule) is preferred.

Examples of aminosilanes include bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane.

Examples of epoxy silanes include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidylpropyltrimethoxysilane, etc.

Examples of the acrylic silane include γ-(methacryloxypropyl)trimethoxysilane, γ-(methacryloxypropyl)methyldimethoxysilane, and γ-(methacryloxypropyl)methyldiethoxysilane.
An example of the mercaptosilane is 3-mercaptopropyltrimethoxysilane.

Examples of vinyl silanes include vinyl tris(β-methoxyethoxy) silane, vinyl triethoxy silane, and vinyl trimethoxy silane.
An example of the ureidosilane is 3-ureidopropyltriethoxysilane.

An example of an acid anhydride functional silane is X-12-967C (compound name: 3-trimethoxysilylpropylsuccinic anhydride) manufactured by Shin-Etsu Chemical Co., Ltd.

Examples of sulfide silanes include bis(3-(triethoxysilyl)propyl) disulfide and bis(3-(triethoxysilyl)propyl) tetrasulfide.
The amount of the adhesion aid added is not particularly limited, but is usually 0.1 to 5 mass %, and preferably 0.5 to 3 mass %, of the total solid content of the negative photosensitive resin composition.

(Preparation of negative photosensitive resin composition)
The method for preparing the negative photosensitive resin composition in this embodiment is not limited, and any known method can be used depending on the components contained in the negative photosensitive resin composition.
For example, the above components can be mixed and dissolved in a solvent to prepare the composition.

(Negative Photosensitive Resin Composition)
The negative type photosensitive resin composition according to this embodiment is used by applying the negative type photosensitive resin composition to a surface comprising a metal such as Al or Cu, then pre-baking to dry and form a resin film, then exposing and developing to pattern the resin film into a desired shape, and then heat-treating the resin film to harden it and form a hardened film.

When producing the permanent film, the pre-baking conditions can be, for example, a temperature of 90°C to 130°C and a heat treatment time of 30 seconds to 1 hour. The heat treatment conditions can be, for example, a temperature of 150°C to 250°C and a heat treatment time of 30 minutes to 10 hours, preferably at about 170°C for 1 to 6 hours.

The film obtained from the negative type photosensitive resin composition of the present embodiment has a maximum elongation of 15 to 200%, preferably 20 to 150%, and an average elongation of 10 to 150%, preferably 15 to 120%, as measured by a tensile test using a Tensilon tester.
Furthermore, since the negative-type photosensitive resin composition of the present embodiment contains the polyimide (A) (negative-type photosensitive polymer) having excellent hydrolysis resistance, even after a HAST test (unsaturated pressurized steam test) is performed for 96 hours under conditions of a temperature of 130° C. and a relative humidity of 85% RH, the rate of decrease in elongation (maximum value, average value) represented by the following formula is 20% or less, preferably 15% or less, and more preferably 12% or less.
[(elongation before test−elongation after test)/elongation before test)]×100

The negative photosensitive resin composition of this embodiment has excellent low-temperature curing properties.
For example, the negative type photosensitive resin composition of the present embodiment can be cured at 170° C. for 4 hours to obtain a cured product having a glass transition temperature (Tg) of 200° C. or higher, preferably 210° C. or higher, and more preferably 220° C. or higher.

Furthermore, the negative photosensitive resin composition of this embodiment can be cured at 170°C for 4 hours to obtain a cured product having a storage modulus E' at 30°C of 2.0 GPa or more, preferably 2.5 GPa or more, and more preferably 3.0 GPa or more. Furthermore, the storage modulus E' at 200°C can be 0.5 GPa or more, preferably 0.7 GPa or more, and more preferably 0.8 GPa or more.

The viscosity of the negative-type photosensitive resin composition according to this embodiment can be set appropriately according to the desired thickness of the resin film. The viscosity of the negative-type photosensitive resin composition can be adjusted by adding a solvent.

A cured product such as a film obtained from the negative photosensitive resin composition of this embodiment has excellent chemical resistance.
Specifically, the film is immersed in a solution of less than 99% by mass of dimethyl sulfoxide and less than 2% by mass of tetramethylammonium hydroxide at 40° C. for 10 minutes, then thoroughly washed with isopropyl alcohol and air-dried, and the film thickness after treatment is measured. The film thickness change rate between the film thickness after treatment and the film thickness before treatment is calculated from the following formula and evaluated as the film thickness reduction rate.
Formula: film reduction rate (%) {(film thickness after immersion - film thickness before immersion) / film thickness before immersion x 100 (%)}

The rate of change in film thickness is preferably 40% or less, and more preferably 30% or less. This means that even when the cured film is subjected to a process in which it is immersed in dimethyl sulfoxide, the film thickness is hardly reduced. This results in a cured film that can maintain its functionality even after being subjected to such a process.

The negative type photosensitive resin composition of the present embodiment is suppressed in curing shrinkage, and in the case where a film is prepared by spin-coating the composition on a silicon wafer surface to a film thickness of 10 μm after drying, pre-baking the composition at 120° C. for 3 minutes, exposing the film to light at 600 mJ/ ^cm2 using a high-pressure mercury lamp, and then heat-treating the film at 170° C. for 120 minutes in a nitrogen atmosphere, the cure shrinkage calculated from the following formula, where the film thickness after the pre-baking is film thickness A and the film thickness after the heat treatment is film thickness B, can be preferably 12% or less, and more preferably 10% or less.
Formula: Cure shrinkage rate [%] = {(film thickness A - film thickness B) / film thickness A} x 100

The negative photosensitive resin composition of this embodiment has high heat resistance, and the resulting film can have a weight loss temperature (Td5) measured by simultaneous thermogravimetry and differential thermal analysis of 200°C or higher, preferably 300°C or higher.

The film made of the negative photosensitive resin composition of this embodiment has suppressed cure shrinkage and has a linear thermal expansion coefficient (CTE) of 200 ppm/°C or less, preferably 100 ppm/°C or less.

A film made from the negative photosensitive resin composition of this embodiment has excellent mechanical strength, and the elastic modulus at 25°C can be 1.0 to 5.0 GPa, preferably 1.5 to 3.0 GPa.

(Application)
The negative photosensitive resin composition of the present embodiment is used to form a resin film for semiconductor devices such as a permanent film, a resist, etc. Among these, from the viewpoint of achieving a good balance between improving the adhesion between the negative photosensitive resin composition and an Al pad after pre-baking and suppressing the generation of residues of the negative photosensitive resin composition during development, improving the adhesion between the cured film of the negative photosensitive resin composition after heat treatment and a metal, and further improving the chemical resistance of the negative photosensitive resin composition after heat treatment, it is preferable to use the composition in applications using a permanent film.

In this embodiment, the resin film includes a cured film of a negative photosensitive resin composition. That is, the resin film according to this embodiment is formed by curing a negative photosensitive resin composition.

The permanent film is made of a resin film obtained by pre-baking, exposing, and developing a negative photosensitive resin composition, patterning it into a desired shape, and then curing it by heat treatment. The permanent film can be used as a protective film, an interlayer film, a dam material, etc. for semiconductor devices.

The resist is composed of a resin film obtained by applying a negative photosensitive resin composition to an object to be masked by the resist by a method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., and then removing the solvent from the negative photosensitive resin composition.

An example of a semiconductor device according to this embodiment is shown in FIG.
The semiconductor device 100 according to this embodiment can be a semiconductor device including the above-mentioned resin film. Specifically, in the semiconductor device 100, one or more of the group consisting of the passivation film 32, the insulating layer 42, and the insulating layer 44 can be the resin film including the cured product of this embodiment. Here, the resin film is preferably the above-mentioned permanent film.

The semiconductor device 100 is, for example, a semiconductor chip. In this case, for example, the semiconductor device 100 is mounted on a wiring board via bumps 52 to obtain a semiconductor package.

The semiconductor device 100 includes a semiconductor substrate on which semiconductor elements such as transistors are provided, and a multi-layer wiring layer (not shown) provided on the semiconductor substrate. The uppermost layer of the multi-layer wiring layer includes an interlayer insulating film 30 and a top-layer wiring 34 provided on the interlayer insulating film 30. The top-layer wiring 34 is made of, for example, aluminum (Al). A passivation film 32 is provided on the interlayer insulating film 30 and the top-layer wiring 34. An opening is provided in a part of the passivation film 32 through which the top-layer wiring 34 is exposed.

A redistribution layer 40 is provided on the passivation film 32. The redistribution layer 40 has an insulating layer 42 provided on the passivation film 32, a redistribution 46 provided on the insulating layer 42, and an insulating layer 44 provided on the insulating layer 42 and the redistribution 46. An opening that connects to the top layer wiring 34 is formed in the insulating layer 42. The redistribution 46 is formed on the insulating layer 42 and in an opening provided in the insulating layer 42, and is connected to the top layer wiring 34. An opening that connects to the redistribution 46 is provided in the insulating layer 44.

In the openings provided in the insulating layer 44, bumps 52 are formed via, for example, a UBM (Under Bump Metallurgy) layer 50. The semiconductor device 100 is connected to a wiring board or the like via the bumps 52, for example.
Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted as long as they do not impair the effects of the present invention.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.
The following compounds were used in the examples.

1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine (hereinafter also referred to as TMDA) represented by the following formula:

4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (hereinafter also referred to as TFMB) represented by the following formula:

4,4'-(hexafluoroisopropylidene)bis[(4-aminophenoxy)benzene] (hereinafter also referred to as HFBAPP) represented by the following formula:

2,2-bis(3-amino-4-hydroxyphenyl)propane (hereinafter also referred to as BAPA) represented by the following formula

2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter also referred to as BAFA) represented by the following formula:

4-[4-(1,3-dioxoisobenzofuran-5-ylcarbonyloxy)-2,3,5-trimethylphenyl]-2,3,6-trimethylphenyl 1,3-dioxoisobenzofuran-5-carboxylate (hereinafter also referred to as TMPBP-TME) represented by the following formula:

[Example 1]
First, 3.54 g (13.7 mmol) of TMDA, 3.65 g (13.7 mmol) of BAPA, and 20.17 g (32.6 mmol) of TMPBP-TME were added to a suitable sized reaction vessel equipped with a stirrer and a condenser, followed by the addition of 73.87 g of GBL to the reaction vessel.
After nitrogen was passed through for 10 minutes, the temperature was raised to 60° C. with stirring, and the reaction was allowed to proceed for 1.5 hours. Thereafter, the reaction was allowed to proceed for an additional 3 hours at 180° C., whereby the bisaminophenol and the acid anhydride were polymerized to prepare a polymerization solution.
The polymer was measured by GPC to find that it had a weight average molecular weight Mw of 15,800 and a polydispersity index (weight average molecular weight Mw/number average molecular weight Mn) of 1.73.
Next, 7.73 g (54.8 mmol) of 2-isocyanatoethyl acrylate (hereinafter also referred to as AOI, manufactured by Showa Denko K.K.) and 23.49 g of γ-butyrolactone (GBL) were added to the total amount of the obtained polyimide solution (27.4 mmol in terms of hydroxyl groups), and the temperature was then raised to 120° C. with stirring, and the mixture was allowed to react for 6 hours.
The reaction solution was diluted with tetrahydrofuran to prepare a diluted solution, and then the diluted solution was added dropwise to methanol to precipitate a white solid. The resulting white solid was collected and vacuum-dried at 40° C. to obtain 23.29 g of a polymer.
The polymer was measured by GPC to find that it had a weight average molecular weight Mw of 17,200 and a polydispersity index (weight average molecular weight Mw/number average molecular weight Mn) of 1.78.
Furthermore, ¹ H-NMR measurement confirmed a peak in the aromatic region (6.8 ppm to 8.9 ppm) with an area ratio corresponding to the number of protons.
In addition, based on the area ratio of the aromatic region (6.8 ppm to 8.9 ppm) and the alkene region (5.8 ppm to 6.5 ppm), the introduction rate of the crosslinking group was 100%.
The resulting polymer contained a repeating unit represented by the following formula in part.

[Comparative Examples 1 to 2]
For Comparative Examples 1 and 2, synthesis was carried out in the same manner as in Example 1, except for the conditions shown in Table 1. The obtained Mw, Mw/Mn, and crosslinking group introduction ratio are shown in the table.

[Solubility in organic solvents]
The solubility in γ-butyrolactone (GBL) of the negative-type photosensitive polymers obtained in Example 1 and Comparative Examples 1 and 2 was evaluated according to the following criteria. The results are shown in Table 1.
(Solubility Evaluation Criteria)
◯: 5% or more by mass of polymer is dissolved △: 1 to 5% by mass of polymer is dissolved ×: Less than 1% by mass of polymer is dissolved

[Hydrolysis resistance]
The reduction rate of the weight average molecular weight of the negative photosensitive polymers obtained in the Examples and Comparative Examples was measured under the following conditions. The results are shown in Table 1.
(Conditions (no triethylamine added))

The following formula was used to calculate the viscosity when 100 parts by mass of a negative photosensitive polymer was added with 400 parts by mass of γ-butyrolactone, 200 parts by mass of 4-methyltetrahydropyran, and 50 parts by mass of water and stirred at 100° C. for 6 hours.
Formula: [(weight average molecular weight before test−weight average molecular weight after test)/weight average molecular weight before test]×100
(Conditions (triethylamine added))

The calculation was performed using the following formula when 10 parts by mass of triethylamine, 400 parts by mass of γ-butyrolactone, 200 parts by mass of 4-methyltetrahydropyran, and 50 parts by mass of water were added to 100 parts by mass of a negative photosensitive polymer and stirred at 100° C. for 6 hours.
Formula: [(weight average molecular weight before test−weight average molecular weight after test)/weight average molecular weight before test]×100

As shown in Table 1, the negative-type photosensitive polymer of the present invention obtained in the examples has excellent solubility in organic solvents and is inhibited from hydrolysis, which is presumably why there is little decrease in elongation and why the decrease in mechanical strength is inhibited.

Reference Signs List 100 Semiconductor device 30 Interlayer insulating film 32 Passivation film 34 Top layer wiring 40 Rewiring layer 42 Insulating layer 44 Insulating layer 46 Rewiring 50 UBM layer 52 Bump

Claims (5)

A structural unit (a1) represented by the following general formula (a1),
A structural unit (a2) represented by the following general formula (a2):
A structural unit (a3) represented by the following general formula (a3):
A negative-type photosensitive polymer comprising:

(In general formula (a1), Y is a divalent organic group.
In general formula (a2), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. A plurality of R ^1s and a plurality of R ^2s may be the same or different.
In formula (a3), Q represents a divalent to tetravalent organic group having 1 to 10 carbon atoms, and a plurality of Q's may be the same or different.
^R5 and ^R6 each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.
m1 and m2 each independently represent an integer of 1 to 3.
X represents a single bond, -SO ₂ -, -C(=O)-, or a linear or branched alkylene group having 1 to 5 carbon atoms, and multiple X's may be the same or different. 2. The negative type photosensitive polymer according to claim 1, wherein Y in the general formula (a1) is a divalent organic group selected from the following general formulae (a1-1), (a1-2), and (a1-3):

(In general formula (a1-1), R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and a plurality of R ^7s and a plurality of R ^8s may be the same or different. R ⁹ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and a plurality of R ^9s may be the same or different. * represents a bond.
In general formula (a1-2), R ¹⁰ and R ¹¹ each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and a plurality of R ^10s and a plurality of R ^11s may be the same or different. * represents a bond.
In general formula (a1-3), Z represents an alkylene group having 1 to 5 carbon atoms or a divalent aromatic group.
* indicates a bond.) The negative-type photosensitive polymer according to claim 2, in which at least one of the two ends is a (meth)acrylate group. 4. The negative photosensitive polymer according to claim 2, comprising structural units represented by the following general formula (1) and the following general formula (2):

(In formula (1), R ¹ and R ² have the same meanings as in formula (a2), and Y has the same meaning as in formula (a1).)

(In formula (2), Q, R ⁵ , R ⁶ , m1, m2, and X are defined as in formula (a3), and Y is defined as in formula (a1).) 5. The negative photosensitive polymer according to claim 2, wherein the reduction rate of the weight average molecular weight measured under the following conditions is 15% or less.
(conditions)
The viscosity is calculated according to the following formula when 400 parts by mass of γ-butyrolactone, 200 parts by mass of 4-methyltetrahydropyran, and 50 parts by mass of water are added to 100 parts by mass of the negative photosensitive polymer and stirred at 100° C. for 6 hours.
Formula: [(weight average molecular weight before test−weight average molecular weight after test)/weight average molecular weight before test]×100

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