JP7043756B2 - Photosensitive resin composition, pattern forming method, electronic device manufacturing method, polymer and polymer manufacturing method - Google Patents

Description

The present invention relates to a photosensitive resin composition, a pattern forming method, a method for producing an electronic device, a polymer, and a method for producing a polymer.

A number of studies have been conducted on photosensitive resin compositions capable of forming patterns for the purpose of being used for producing electronic devices and the like.
As an example of the study, there is a photosensitive resin composition using a polymer having a maleimide structure in the main chain. Specifically, in the examples of Patent Document 1, as resins, methacrylic acid, styrene, glycidyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8-ylmethacrylate and N- (4). -It is described that a photosensitive resin composition was prepared using a resin polymerized from (hydroxyphenyl) maleimide.

Japanese Patent No. 4127150

In recent years, the miniaturization and complexity of electronic devices have been increasing. Along with this, the photosensitive resin composition is also required to have higher performance.
However, according to the findings of the present inventors, the conventional photosensitive resin composition is not always satisfactory in the residual film of the pattern after the exposure / development treatment. Specifically, for example, in the case of a positive photosensitive resin composition, the unexposed portion that should remain as a pattern after the exposure / development process may actually melt and the pattern may not be formed satisfactorily. rice field.
Further, in the conventional photosensitive resin composition, cracks may occur on the surface when the coating film is formed.

The present invention has been made in view of such circumstances. That is, one of the objects of the present invention is to obtain a photosensitive resin composition having good residual film property and reduced generation of cracks.

As a result of diligent studies, the present inventors have found that the above problems can be achieved by using a resin containing two specific structural units as the resin in the photosensitive resin composition, and have completed the present invention.

According to the present invention
A photosensitive resin composition comprising a polymer containing the structural unit represented by the following general formula (1) and the structural unit represented by the following general formula (2) .
A photosensitive resin composition in which the polymer further contains a structural unit represented by the chemical formula (3) described later.
Is provided.

一般式（１）において、
Ｒは、１価の置換基を表し、
ｍは、１～３の整数を表し、
ｎは、０～４の整数を表す。
ただし、ｍ＋ｎは、５以下である。
一般式（２）において、
Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は、それぞれ独立に、水素原子、または、カルボキシル基以外の１価の有機基を表し、
ｎは、０～２の整数を表す。

In the general formula (1)
R represents a monovalent substituent and represents
m represents an integer of 1 to 3 and represents
n represents an integer of 0 to 4.
However, m + n is 5 or less.
In the general formula (2)
R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group other than a carboxyl group, respectively.
n represents an integer of 0 to 2.

Further, according to the present invention,
A step of forming a photosensitive resin film using the photosensitive resin composition,
The step of exposing the photosensitive resin film,
A pattern forming method including a step of developing the photosensitive resin film is provided.

Further, according to the present invention,
A method for manufacturing an electronic device including the pattern forming method is provided.

According to the present invention, it is possible to obtain a photosensitive resin composition having good residual film property and reduced generation of cracks.

Hereinafter, embodiments of the present invention will be described in detail.
In the present specification, the notation "a to b" in the description of the numerical range means a or more and b or less unless otherwise specified.
In the notation of a group (atomic group) in the present specification, the notation that does not indicate whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
The notation "(meth) acrylic" herein represents a concept that includes both acrylic and methacrylic. The same applies to similar notations such as "(meth) acrylate".

<Photosensitive resin composition>
The photosensitive resin composition of the present embodiment contains a polymer containing a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2).

In the general formula (1)
R represents a monovalent substituent and represents
m represents an integer of 1 to 3 and represents
n represents an integer of 0 to 4.
However, m + n is 5 or less.
In the general formula (2)
R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group other than a carboxyl group, respectively.
n represents an integer of 0 to 2.

It is not always clear why the photosensitive resin composition of the present embodiment contains this polymer to improve the residual film property and reduce the occurrence of cracks. However, the reason for this is presumed as follows.
There are various possible causes for the occurrence of cracks, but one is thought to be related to the mechanical strength of the resin. According to the findings of the present inventors, it is not easy to obtain a polymer having a high molecular weight (sufficient chain length) by using the monomer of the general formula (1) alone (or the monomer of the general formula (2) alone), and it is industrialized. Only short chain length polymers can be obtained. Polymers with short chain lengths have insufficient mechanical strength and are prone to cracking due to environmental changes such as heating, cooling, and development. On the other hand, the monomer of the general formula (1) and the monomer of the general formula (2) are easily copolymerized, and a polymer having a high molecular weight (long chain length) can be easily obtained. That is, it is presumed that the mechanical strength of the polymer can be sufficiently increased and contributes to the reduction of cracks.
Regarding the residual film property, the phenol structure in the structural unit represented by the general formula (1) interacts with a photosensitive agent (diazoquinone compound, etc. described later), so that dissolution in the developing solution is appropriately suppressed. It is presumed that the residual film property is improved by this.

The components that can be contained in the photosensitive resin composition of this embodiment will be described.

[polymer]
The photosensitive resin composition of the present embodiment contains a polymer containing a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2). The present invention is also an invention relating to this polymer.
Hereinafter, this polymer is also referred to as "specific polymer".

In the general formula (1)
R represents a monovalent substituent and represents
m represents an integer of 1 to 3 and represents
n represents an integer of 0 to 4.
However, m + n is 5 or less.
In the general formula (2)
R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group other than a carboxyl group, respectively.
n represents an integer of 0 to 2.

The structural unit represented by the general formula (1) will be described.
The monovalent substituent of R may be arbitrary, and examples thereof include a halogen atom, a hydroxy group, a cyano group, an amino group, and a monovalent organic group.
When R is a monovalent organic group, examples of the organic group include an alkyl group, a cycloalkyl group, an alkoxy group, an aryl group, an aralkyl group, an alkylcarbonyl group, an alkoxycarbonyl group, and an alkylcarbonyloxy group. These may be further substituted with other substituents (hydroxy group, halogen atom, etc.).
The alkyl group may be either linear or branched, and examples thereof include an alkyl group having 1 to 20 carbon atoms, preferably a linear and branched alkyl group having 1 to 12 carbon atoms.
Examples of the cycloalkyl group include a cycloalkyl group having 3 to 8 carbon atoms.
The alkoxy group may be linear, branched or cyclic, and may be, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 6 carbon atoms, or 3 to 3 carbon atoms. 8 cyclic alkoxy groups can be mentioned.
n is preferably 0 or 1, more preferably 0.
m is preferably 1.

The structural unit represented by the general formula (1) preferably includes a structural unit represented by the following chemical formula (1-1).

The specific polymer may contain a plurality of types of structural units represented by the general formula (1).
The content of the structural unit represented by the general formula (1) in all the structural units of the specific polymer is preferably 5 to 40 mol%, more preferably 5 to 30 mol%.
The content of the structural unit represented by the general formula (1) in the specific polymer can also be obtained from the amount of the charged monomer and the amount of the residual monomer in the polymer synthesis (polymerization), and can be obtained from the ¹³ C-NMR measurement results. It can also be obtained from the peak area. The same applies to other structural units.

The structural unit represented by the general formula (2) will be described.
Specific examples of the monovalent organic group of R ¹ , R ² , R ³ and R ⁴ include the same as in the case where R in the general formula (1) is a monovalent organic group. However, the carboxyl group is excluded as a monovalent organic group.
R ¹ , R ² , R ³ and R ⁴ are preferably hydrogen atoms.
n is preferably 0 or 1, more preferably 0.

The structural unit represented by the general formula (2) preferably does not contain a crosslinkable group. In other words, R ¹ , R ² , R ³ and R ⁴ in the structural unit represented by the general formula (2) do not contain a crosslinkable group.
Here, the "crosslinkable group" typically refers to a thermally crosslinkable group capable of forming a crosslinked structure by heat treatment. Specific examples thereof include an epoxy group, an oxetanyl group, an acid anhydride group, and a group containing an ethylenically unsaturated double bond. Such crosslinkable groups can form a crosslinked structure with each other by heat treatment or the like, self-polymerize, or form a crosslinked structure via a crosslinking agent.

The specific polymer may contain a plurality of types of structural units represented by the general formula (2).
The content of the structural unit represented by the general formula (2) in all the structural units of the specific polymer is preferably 10 to 95 mol%, more preferably 20 to 60 mol%.

The specific polymer further preferably contains a structural unit (maleimide structural unit) represented by the following chemical formula (3).

By including the structural unit represented by the chemical formula (3) in the specific polymer, it is expected that the developability will be improved in addition to the improvement of the residual film property and the reduction of the generation of cracks.
Remaining film property is related to "difficulty in dissolving" in the developing solution, and developability is related to "easiness of dissolving" in the developing solution, so it is an incompatible performance, but maleimide is probably weaker than carboxylic acid (mild). It is presumed that the residual film property and developability are appropriately adjusted by having a Bronsted acid having an appropriate alkali solubility and the like.
Further, as compared with the structural unit of the general formula (1), the structural unit of the chemical formula (3) can be expected to have a merit that the polymerizability of the monomer is high and a high molecular weight polymer can be easily obtained because there is no substituent.

When the specific polymer contains the structural unit represented by the chemical formula (3), the content thereof is preferably 10 to 50 mol%, more preferably 20 to 40 mol%, in the total structural unit of the specific polymer.

The specific polymer further preferably contains a structural unit represented by the following general formula (4).

In the general formula (4), R ^c represents a monovalent organic group containing a cyclic structure.
Examples of the monovalent organic group containing the cyclic structure of R ^c include a monocyclic or polycyclic cycloalkyl group, an aryl group, an aralkyl group and the like. These may be further substituted with other substituents (alkyl group, hydroxy group, halogen atom, etc.).
As R ^c , an aryl group is particularly preferable from the viewpoint of further reducing cracks and improving developability.
Examples of the cycloalkyl group of R ^c include a monocyclic cycloalkyl group having 3 to 8 carbon atoms.
Examples of the aryl group of R ^c include those having 6 to 10 carbon atoms such as a phenyl group and a naphthyl group.
Examples of the aralkyl group of R ^c include those having 7 to 11 carbon atoms such as a benzyl group and a naphthylmethyl group.

When the specific polymer contains the structural unit represented by the general formula (4), the content thereof is preferably 10 to 70 mol%, more preferably 15 to 60 mol% in the total structural unit of the specific polymer.

The particular polymer may contain other structural units not described above.
However, the specific polymer preferably does not contain structural units having an oxetanyl group. Since the specific polymer does not contain a structural unit having an oxetanyl group, improvement in developability can be expected.

The weight average molecular weight (Mw) of the specific polymer is not particularly limited, but is preferably 10,000 or more, more preferably 10,000 to 50,000, and even more preferably 10,000 to 30,000. It is presumed that when Mw is 10,000 or more, the chain length of the polymer becomes moderately long, and as a result, the mechanical strength of the film is improved. Therefore, it is considered that cracks can be further reduced.
The dispersity of the specific polymer (weight average molecular weight Mw / number average molecular weight Mn) is typically 1.2 to 5.0, preferably 1.5 to 3.0.
In addition, Mw and Mn can be obtained by gel permeation chromatography (GPC) measurement using polystyrene as a standard substance.

The alkali dissolution rate of the specific polymer is preferably 300 to 20000 Å / sec, more preferably 400 to 15000 Å / sec. By setting such an alkali dissolution rate, it is possible to further improve both the developability and the residual film property.
For the method of measuring the alkali dissolution rate, refer to the examples described later.

[Manufacturing method of specific polymer]
The specific polymer can be produced by appropriately applying a known polymer synthesis method, and can be produced, for example, by going through the following steps.
The step of charging the first solution containing at least the monomer represented by the following general formula (m2) and the polymerization initiator into the reaction vessel, and
The starting step of raising the temperature of the first solution to start the polymerization reaction, and
A follow-up step of adding a second solution containing at least the monomer represented by the following general formula (m1) and not containing the monomer represented by the following general formula (m2) into the reaction vessel.

The definitions of R, m and n in the general formula (m1) are the same as those in the general formula (1).
The definitions of R ¹ , R ² , R ³ , R ⁴ and n in the general formula (m2) are the same as those in the general formula (2).

The monomer represented by the general formula (m2) (which becomes the structural unit of the general formula (2) by polymerization) is the monomer represented by the general formula (m1) (which becomes the structural unit of the general formula (1) by polymerization). It is considered that it is harder to polymerize than. Therefore, when the monomer represented by the general formula (m1) and the monomer represented by the general formula (m2) are completely mixed at one time and the polymerization reaction is started, the monomer represented by the general formula (m1) is obtained. While preferentially polymerizing, the monomer represented by the general formula (m2) is not consumed so much, and a desired amount of the structural unit of the general formula (1) may not be incorporated into the polymer.

Therefore, as described above, first, the monomer represented by the general formula (m2) is charged in the reaction vessel, the polymerization reaction is started, and then the second solution containing the monomer represented by the general formula (m1) is contained. It is considered that the amount of the monomer represented by the general formula (m1) and the amount of the monomer represented by the general formula (m2) can be easily kept constant in the polymerization system by adding. As a result, it is considered that it becomes easy to obtain a specific polymer having a desired composition.

The method for producing a specific polymer will be described more specifically.

-Preparation step The first solution contains at least the monomer represented by the general formula (m2) and the polymerization initiator, but may also contain other components.
As the polymerization initiator, a radical polymerization initiator, for example, a known azo compound initiator or an organic peroxide initiator can be used.
As other components, the monomer represented by the general formula (m1), the monomer corresponding to the structural unit represented by the above-mentioned general formula (3), and the structural unit represented by the above-mentioned general formula (4) are supported. It can contain a monomer, a molecular weight adjusting agent, a chain transfer agent (for example, a known thiol compound) and the like.
The above components are uniformly mixed and dissolved using an appropriate organic solvent as a solvent. As the organic solvent, an ester solvent, a ketone solvent, an ether solvent and the like can be used. More specifically, methyl ethyl ketone (MEK), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethyl ether, tetrahydrofuran (THF), toluene, ethyl acetate, butyl acetate and the like can be mentioned. Two or more kinds of solvents may be mixed and used as an organic solvent.
Further, it is preferable that the first solution reduces the dissolved oxygen in the system by nitrogen bubbling or the like.

-Starting step By raising the temperature of the first solution in the reaction vessel, the polymerization initiator in the first solution is cleaved and the polymerization reaction is started. The temperature rise depends on the cleavage property of the polymerization initiator, but the temperature is raised to, for example, 50 to 90 ° C.

-Addition step The second solution in the addition step is not particularly limited as long as it contains a monomer represented by the general formula (m1) and does not contain a monomer represented by the following general formula (m2), and is not particularly limited as described above. A monomer corresponding to the structural unit represented by the general formula (3), a monomer corresponding to the structural unit represented by the above-mentioned general formula (4), and the like may be additionally included. It may also contain additional polymerization initiators, chain transfer agents, molecular weight modifiers and the like. A second solution can be obtained by uniformly mixing and dissolving these components with an appropriate organic solvent in the same manner as the first solution.
The second solution is added dropwise to the reaction vessel, for example, over 1 to 24 hours.
A solution containing a specific polymer can be obtained by each of the above steps.

A solution containing the specific polymer is poured into a large amount of a poor solvent (for example, a mixed solution of pure water and methanol) to precipitate the specific polymer, then filtered, washed, and dried to remove residual monomers and the like. A high-purity specific polymer that has been removed can be obtained.

[Polymer other than specific polymer]
The photosensitive resin composition of the present embodiment contains at least a specific polymer (a polymer containing a structural unit represented by the chemical formula (1) and a structural unit represented by the general formula (2)), but other than that. It may contain a polymer.
Examples of such a polymer include known alkali-soluble resins such as novolak resin, polyhydroxystyrene, and poly (meth) acrylic acid. Among these, novolak resin is preferable from the viewpoint of cost, availability, compatibility with the above polymer, and the like.
When the photosensitive resin composition contains such a polymer, the amount thereof is preferably 1 to 30 parts by mass, more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the above polymer.

[Photosensitizer]
The photosensitive resin composition of the present embodiment preferably contains a photosensitive agent.
The photosensitive agent generates an acid by irradiation with light such as g-ray, i-ray, and deep ultraviolet light.

Specifically, as the photosensitizer, a photosensitive diazoquinone compound, onium salt (sulfonium salt, iodonium salt, etc.), sulfonic acid ester compound, oxime sulfonate compound, diazodisulfone compound, 2-nitrobenzyl ester compound, N-iminosulfonate compound. , Imidsulfonate compounds, 2,6-bis (trichloromethyl) -1,3,5-triazine compounds, dihydropyridine compounds and the like.

In particular, when the photosensitive resin composition is of the positive type (the exposed portion dissolves when developed with an alkaline developer after pattern exposure), the photosensitive agent preferably contains a diazoquinone compound. This makes it possible to obtain a positive pattern with good sensitivity and resolution.
As the diazoquinone compound, for example, one or more of the following compounds can be used.

In each of the above diazoquinone compounds, Q is any of the structures represented by the following formula (a), the lower formula (b) and the lower formula (c), or a hydrogen atom. However, at least one of the Qs of each diazoquinone compound is any of the structures represented by the following formula (a), the lower formula (b) and the lower formula (c). Further, n is an integer of 1 to 5.
The Q of the diazoquinone compound preferably contains the following formula (a) or the following formula (b). This makes it possible to improve the transparency of the photosensitive resin composition. Therefore, the appearance of the photosensitive resin composition can be improved.

The amount of the photosensitive agent in the photosensitive resin composition 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 polymer (including not only the specific polymer but also other polymers). Is.

[Silane coupling agent]
The photosensitive resin composition of the present embodiment preferably contains a silane coupling agent. This makes it possible to improve the adhesion to the substrate.

Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, and 3-methacryloxypropyl. Methyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl)- 3-Aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-Aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxypropyl) tetrasulfide, 3-isoxapropyltri Examples thereof include, but are not limited to, ethoxysilane and a silicon compound obtained by reacting a silicon compound having an amino group with an acid dianhydride or an acid anhydride.

As the silane coupling agent, only one kind may be used, or two or more kinds may be used in combination.
When the photosensitive resin composition contains a silane coupling agent, the amount thereof is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer (including not only the specific polymer but also other polymers). , More preferably 1 to 20 parts by mass. Within the above range, both adhesion and storage stability of the photosensitive resin composition can be achieved.

[Surfactant]
The photosensitive resin composition of the present embodiment preferably contains a surfactant. By containing the surfactant, the coatability when the photosensitive resin composition is applied onto the substrate to obtain a resin film is improved. For example, it is possible to reduce the radial striation formed on the film during rotary coating.
As the surfactant, a nonionic surfactant is particularly preferable.

Examples of the surfactant include a compound containing a fluorine-containing group (such as an alkylfluoride group) or a silanol group, or a compound having a siloxane bond as a main skeleton. In this embodiment, nonionic, fluorine-based surfactants or silicone-based surfactants are preferable. Examples of the fluorine-based surfactant include Megafuck F-171, F-173, F-444, F-470, F-471, F-475, F-482, F-477, and F manufactured by DIC Corporation. -554, F-556 and F-557, Novec FC4430 manufactured by Sumitomo 3M Ltd., FC4432 and the like, but are not limited thereto.

Only one type of surfactant may be used, or two or more types may be used in combination.
When a surfactant is used, the amount thereof is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the polymer (including not only the specific polymer but also other polymers).

[solvent]
The photosensitive resin composition of the present embodiment is preferably obtained by dissolving or dispersing the above-mentioned various components (and, in some cases, other components shown below) in a solvent.
The solvent is preferably an organic solvent. Examples of the organic solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and propylene. Glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate and methyl-3-methoxypro Pionate and the like can be mentioned.

Only one type of solvent may be used, or two or more types may be used in combination.
The amount of the solvent used is such that the concentration of the non-volatile component of the photosensitive resin composition is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, and more preferably 10 to 30% by mass.

[Other ingredients]
The photosensitive resin composition of the present embodiment may contain various components other than the above. For example, components such as a dissolution accelerator, an antioxidant, a filler, a photopolymerization initiator, and a sensitizer may be further contained as long as the effects of the present invention are not impaired.
The photosensitive resin composition of the present embodiment may or may not contain a cross-linking agent, but preferably does not contain a cross-linking agent.

According to the photosensitive resin composition of the present embodiment, as described above, the effects of improving the residual film property and reducing the generation of cracks can be expected. In addition to these effects, by optimizing the composition of the polymer, the developability is improved (development residue is reduced, etc.) and the thermal flow resistance is improved (the formed pattern is not deformed even if it is heated). ) Effects can also be expected.
In addition, the specific polymer has low absorption of ultraviolet rays due to its structure and has a high ultraviolet transmittance. That is, the irradiation light is not unnecessarily absorbed. This can be expected to increase the sensitivity of the composition and improve the pattern shape.

<Pattern formation method>
An embodiment of a pattern forming method using the above-mentioned photosensitive resin composition will be described.
The pattern forming method of the present embodiment includes a step of forming a photosensitive resin film using the above-mentioned photosensitive resin composition, a step of exposing the photosensitive resin film, and a step of developing the photosensitive resin film.

The process of forming the photosensitive resin film using the photosensitive resin composition will be described.
The photosensitive resin film is typically formed by applying the photosensitive resin composition on a suitable substrate. The substrate is not particularly limited, and examples thereof include a silicon wafer, a ceramic substrate, an aluminum substrate, a SiC wafer, a GaN wafer, and a copper-clad laminate. The substrate includes, for example, a substrate on which a semiconductor element or a display element is formed on the surface, in addition to the raw substrate. In order to improve the adhesiveness, the surface of the substrate may be treated with an adhesive auxiliary such as a silane coupling agent.
Examples of the method of applying the photosensitive resin composition to the substrate include rotary coating using a spinner, spray coating using a spray coater, dipping, printing, roll coating, and an inkjet method. Of these, rotary coating is preferable.
After the photosensitive resin composition is applied to the substrate, it is preferable to heat the substrate on a hot plate (pre-baking). The prebake temperature is usually 80-140 ° C, preferably 90-120 ° C. The prebaking time is usually about 30 to 600 seconds, preferably about 30 to 300 seconds.
The thickness of the photosensitive resin film is appropriately adjusted, for example, between 0.1 and 100 μm.

The process of exposing the photosensitive resin film will be described.
By irradiating the photosensitive resin film with an active light beam for exposure through an appropriate photomask, a latent image reflecting the pattern of the photomask can be formed on the photosensitive resin film.
As the active light beam for exposure, for example, X-ray, electron beam, ultraviolet ray, visible light and the like can be used. In terms of wavelength, active light rays having a wavelength of 200 to 500 nm are preferable. From the viewpoint of pattern resolution and handleability, the light source is preferably g-line, h-line or i-line of a mercury lamp, and i-line is particularly preferable. Further, two or more light rays may be mixed and used. As the exposure apparatus, a contact aligner, a mirror projection or a stepper is preferable.
After the exposure, the photosensitive resin film may be heated again if necessary (heating after exposure: Post Exposure Bake). The temperature is, for example, 80 to 150 ° C, preferably 90 to 120 ° C. The time is, for example, 30 to 600 seconds, preferably 30 to 300 seconds.

The process of developing the photosensitive resin film will be described.
Development can be carried out by using a developer, for example, by a method such as a dipping method, a paddle method, or a rotary spray method. By the development, the exposed portion (in the case of the positive type) or the unexposed portion (in the case of the negative type) is eluted and removed from the coating film, and a patterned resin film can be obtained.
As the developing solution, an alkaline aqueous solution is preferably used. Specifically, (i) an inorganic alkaline aqueous solution such as sodium hydroxide, sodium carbonate, sodium silicate and ammonia, (ii) an organic amine aqueous solution such as ethylamine, diethylamine, triethylamine and triethanolamine, and (iii) tetramethylammonium. Examples thereof include an aqueous solution of a quaternary ammonium salt such as hydroxide and tetrabutylammonium hydroxide.
A water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like may be added to the developing solution.
As the developing solution, an aqueous solution of tetramethylammonium hydroxide is preferable. The concentration of tetramethylammonium hydroxide in this aqueous solution is preferably 0.1 to 10% by mass, more preferably 0.3 to 5% by mass.

After the development treatment, washing with a rinsing solution or the like may be performed. Examples of the rinsing solution include distilled water, methanol, ethanol, isopropanol, propylene glycol monomethyl ether and the like. These can be used alone or in combination of two or more.
Further, after the development process, the entire surface may be exposed or the post-baking process may be performed.
The irradiation amount of the full exposure is adjusted, for example, between 1 and 500 mJ / cm ² . The post-baking treatment can be performed at, for example, 100 to 200 ° C. for 5 to 15 minutes.

<Manufacturing method of electronic devices>
The above-mentioned pattern forming method can be applied to the manufacture of electronic devices.
For example, the semiconductor substrate can be processed by selectively etching the semiconductor substrate using the pattern obtained by the above method as an etching mask. That is, the electronic device can be manufactured by the step including the above-mentioned pattern forming method.
The specific polymer of the present embodiment contains many structures having high etching resistance such as an aryl moiety and a norbornane skeleton. Therefore, it is preferably applied to an etching mask.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.
Hereinafter, an example of the reference form will be added.
1. 1.
A photosensitive resin composition comprising a polymer containing the structural unit represented by the above-mentioned general formula (1) and the above-mentioned structural unit represented by the general formula (2).
In the above general formula (1),
R represents a monovalent substituent and represents
m represents an integer of 1 to 3 and represents
n represents an integer of 0 to 4.
However, m + n is 5 or less.
In the above general formula (2),
R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group other than a carboxyl group, respectively.
n represents an integer of 0 to 2.
2. 2.
1. 1. The photosensitive resin composition according to the above.
A photosensitive resin composition comprising a polymer in which the polymer does not contain a structural unit having an oxetanyl group.
3. 3.
1. 1. Or 2. The photosensitive resin composition according to the above.
A photosensitive resin composition in which the structural unit represented by the above-mentioned general formula (2) contains a structural unit that does not contain a crosslinkable group.
4.
1. 1. ~ 3. The photosensitive resin composition according to any one of the above.
A photosensitive resin composition in which the polymer further contains a structural unit represented by the above-mentioned chemical formula (3).
5.
1. 1. ~ 3. The photosensitive resin composition according to any one of the above.
A photosensitive resin composition in which the polymer further comprises a structural unit represented by the above-mentioned general formula (4).
In the above-mentioned general formula (4), R ^c represents a monovalent organic group containing a cyclic structure.
6.
1. 1. ~ 5. The photosensitive resin composition according to any one of the above.
A photosensitive resin composition in which the structural unit represented by the above-mentioned general formula (1) contains the structural unit represented by the above-mentioned chemical formula (1-1).
7.
1. 1. ~ 6. The photosensitive resin composition according to any one of the above.
A photosensitive resin composition having a weight average molecular weight of 10,000 or more of the polymer.
8.
1. 1. ~ 7. The photosensitive resin composition according to any one of the above.
Further, a photosensitive resin composition containing a novolak resin.
9.
1. 1. ~ 8. A step of forming a photosensitive resin film using the photosensitive resin composition according to any one of the above.
The step of exposing the photosensitive resin film and
Step of developing the photosensitive resin film
A pattern forming method including.
10.
9. A method for manufacturing an electronic device, including the method for forming a pattern according to the above.
11.
A polymer containing the structural unit represented by the above-mentioned general formula (1) and the structural unit represented by the above-mentioned general formula (2).
In the above general formula (1),
R represents a monovalent substituent and represents
m represents an integer of 1 to 3 and represents
n represents an integer of 0 to 4.
However, m + n is 5 or less.
In the above general formula (2),
R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group other than a carboxyl group, respectively.
n represents an integer of 0 to 2.
12.
11. The polymer described in
A polymer containing no structural unit having an oxetanyl group.
13.
11. Or 12. The polymer described in
A polymer in which the structural unit represented by the above-mentioned general formula (2) contains a structural unit that does not contain a crosslinkable group.
14.
11. ~ 13. The polymer according to any one of
Further, a polymer containing a structural unit represented by the above-mentioned chemical formula (3).
15.
11. ~ 14. The polymer according to any one of
Further, a polymer containing a structural unit represented by the above-mentioned general formula (4).
In the above-mentioned general formula (4), R ^c represents a monovalent organic group containing a cyclic structure.
16.
11. ~ 15. The polymer according to any one of
A polymer in which the structural unit represented by the above-mentioned general formula (1) includes the structural unit represented by the above-mentioned chemical formula (1-1).
17.
11. ~ 16. The polymer according to any one of
A polymer having a weight average molecular weight of 10,000 or more.
18.
11. ~ 17. The method for producing a polymer according to any one of the above.
The step of charging the first solution containing at least the monomer represented by the above-mentioned general formula (m2) and the polymerization initiator into the reaction vessel, and
The starting step of raising the temperature of the first solution to start the polymerization reaction, and
With the addition step of adding a second solution containing at least the monomer represented by the above-mentioned general formula (m1) and not containing the monomer represented by the above-mentioned general formula (m2) into the reaction vessel.
A method for producing a polymer, including.
In the above general formula (m1),
R represents a monovalent substituent and represents
m represents an integer of 1 to 3 and represents
n represents an integer of 0 to 4.
However, m + n is 5 or less.
In the above general formula (m2)
R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group other than a carboxyl group, respectively.
n represents an integer of 0 to 2.

Embodiments of the present invention will be described in detail based on Examples and Comparative Examples. The present invention is not limited to the examples.

<Polymer synthesis>
(Synthesis Example 1: Synthesis of Polymer 1)
In the reaction vessel, 2-norbornene (75 mass% toluene solution, 21.3 g, 0.169 mol), maleimide (8.9 g, 0.092 mol), N-phenylmaleimide (15.9 g, 0.092 mol), sum. A polymerization initiator V-601 (2.6 g, 0.011 mol) manufactured by Kojunyaku Co., Ltd. and 19.3 g of methyl ethyl ketone (hereinafter abbreviated as MEK, the same applies to other synthetic examples) were added, and the mixture was stirred and dissolved.
Then, after removing the dissolved oxygen in the system by nitrogen bubbling, it was heated. When the internal temperature reached 60 ° C., maleimide (7.5 g, 0.077 mol), 4-hydroxyphenylmaleimide (10.7 g, 0.056 mol) and N-phenylmaleimide (13.4 g, 0.077 mol) were added. A solution dissolved in a mixed solvent of 34.4 g of MEK and 16.02 g of propylene glycol monomethyl ether was added over 6 hours.
Then, the temperature was raised to 70 ° C. and the reaction was further carried out for 3 hours. The reaction mixture was then cooled to room temperature and 100 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, washed with pure water, and vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 56.4 g, and the yield was 75%. The obtained polymer had a weight average molecular weight Mw of 14,900, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 2.17, and an alkali dissolution rate of 8,000 Å / sec.

(Synthesis Example 2: Synthesis of Polymer 2)
In the reaction vessel, 2-norbornene (75% mass toluene solution, 21.0 g, 0.167 mol), maleimide (5.2 g, 0.054 mol), N-phenylmaleimide (9.3 g, 0.054 mol), sum. A polymerization initiator V-601 (2.6 g, 0.011 mol) and 12.3 g of MEK manufactured by Kojunyaku Co., Ltd. were added, and the mixture was stirred and dissolved.
Then, after removing the dissolved oxygen in the system by nitrogen bubbling, it was heated. When the internal temperature reaches 60 ° C., maleimide (11.1 g, 0.114 mol), 4-hydroxyphenylmaleimide (21.1 g, 0.112 mol), and N-phenylmaleimide (10.1 g, 0.058 mol). Was dissolved in a mixed solvent of 25.8 g of MEK and 31.7 g of propylene glycol monomethyl ether, and the solution was added over 6 hours.
Then, the temperature was raised to 70 ° C. and the reaction was further carried out for 3 hours. The reaction mixture was then cooled to room temperature and 100 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, washed with pure water, and vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 45.4 g, and the yield was 61%. The obtained polymer had a weight average molecular weight Mw of 11,000, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 1.98, and an alkali dissolution rate of 14,800 Å / sec.

(Synthesis Example 3: Synthesis of Polymer 3)
In the reaction vessel, 2-norbornene (75 mass% toluene solution, 21.0 g, 0.167 mol), maleimide (2.3 g, 0.023 mol), N-cyclohexyl maleimide (4.1 g, 0.023 mol), sum. A polymerization initiator V-601 (2.6 g, 0.011 mol) and MEK 6.9 g manufactured by Kojunyaku Co., Ltd. were added, and the mixture was stirred and dissolved.
Then, after removing the dissolved oxygen in the system by nitrogen bubbling, it was heated. When the internal temperature reached 60 ° C., maleimide (14.0 g, 0.144 mol), 4-hydroxyphenyl maleimide (10.6 g, 0.056 mol), and N-cyclohexyl maleimide (25.9 g, 0.144 mol). Was dissolved in a mixed solvent of 47.0 g of MEK and 15.8 g of propylene glycol monomethyl ether, and the solution was added over 6 hours.
Then, the temperature was raised to 70 ° C. and the reaction was further carried out for 3 hours. The reaction mixture was then cooled to room temperature and 100 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, washed with pure water, and vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 62.0 g, and the yield was 83%. The obtained polymer had a weight average molecular weight Mw of 14,700, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 2.12, and an alkali dissolution rate of 1,700 Å / sec.

(Synthesis Example 4: Synthesis of Polymer 4)
In the reaction vessel, 2-norbornene (75 mass% toluene solution, 19.0 g, 0.151 mol), norbornene carboxylic acid (60 mass% MEK solution, 23.2 g, 0.101 mol), N-phenylmaleimide (23. 9 g, 0.138 mol), a polymerization initiator V-601 (2.3 g, 0.010 mol) manufactured by Wako Pure Chemical Industries, Ltd. and 18.4 g of MEK were added, and the mixture was stirred and dissolved.
Then, after removing the dissolved oxygen in the system by nitrogen bubbling, the mixture was heated, and when the internal temperature reached 60 ° C., 4-hydroxyphenylmaleimide (9.5 g, 0.050 mol) and N-phenylmaleimide (N-phenylmaleimide (9.5 g, 0.050 mol)). A solution prepared by dissolving 11.0 g, 0.064 mol) in a mixed solvent of 28.3 g of MEK and 14.3 g of propylene glycol monomethyl ether was added over 6 hours.
Then, the temperature was raised to 70 ° C. and the reaction was further carried out for 3 hours. The reaction mixture was then cooled to room temperature and 100 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, washed with pure water, and vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 43.4 g, and the yield was 58%. The obtained polymer had a weight average molecular weight Mw of 9,700, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 1.96, and an alkali dissolution rate of 430 Å / sec.

(Synthesis Example 5: Synthesis of Polymer 5)
In the reaction vessel, 2-norbornene (75 mass% toluene solution, 21.3 g, 0.169 mol), polymerization initiator V-601 (2.6 g, 0.011 mol) manufactured by Wako Pure Chemical Industries, Ltd. and MEK 16.5 g. Was added, and the mixture was stirred and dissolved.
Then, after removing the dissolved oxygen in the system by nitrogen bubbling, it was heated. When the internal temperature reached 70 ° C., maleimide (16.4 g, 0.169 mol), 4-hydroxyphenyl maleimide (10.7 g, 0.056 mol), and N-phenylmaleimide (29.3 g, 0.169 mol). Was dissolved in a mixed solvent of 74.7 g of MEK and 16.0 g of propylene glycol monomethyl ether, and the solution was added over 4 hours.
Then, the temperature was raised to 80 ° C. and the reaction was further carried out for 3 hours. The reaction mixture was then cooled to room temperature and 62.5 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, further washed with pure water, and then vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 62.5 g, and the yield was 83%. The obtained polymer had a weight average molecular weight Mw of 6,800, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 1.82, and an alkali dissolution rate of 7,800 Å / sec.

(Synthesis Example 6: Synthesis of Polymer 6 (for comparison))
In the reaction vessel, norbornencarboxylic acid (44.4 g, 0.321 mol), N-phenylmaleimide (31.0 g, 0.179 mol), polymerization initiator V-601 (7.4 g, manufactured by Wako Pure Chemical Industries, Ltd.) 0.032 mol) and 29.6 g of MEK were added, and the mixture was stirred and dissolved.
Then, after removing the dissolved oxygen in the system by nitrogen bubbling, it was heated. When the internal temperature reached 70 ° C., a solution prepared by dissolving N-phenylmaleimide (24.6 g, 0.142 mol) in 63.1 g of MEK was added over 4 hours.
Then, it reacted at 70 degreeC for 3 hours. The reaction mixture was then cooled to room temperature and 133.3 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, further washed with pure water, and then vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 65.7 g, and the yield was 66%. The obtained polymer had a weight average molecular weight Mw of 6,800, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 1.91, and an alkali dissolution rate of 4,000 Å / sec.

(Synthesis Example 7: Synthesis of Polymer 7 (for comparison))
In the reaction vessel, norbornene carboxylic acid (28.1 g, 0.203 mol), N-phenylmaleimide (30.1 g, 0.174 mol), polymerization initiator V-601 (7.8 g, manufactured by Wako Pure Chemical Industries, Ltd.) 0.034 mol) and 18.7 g of MEK were added, and the mixture was stirred and dissolved.
Then, after removing the dissolved oxygen in the system by nitrogen bubbling, it was heated. When the internal temperature reached 70 ° C., a solution prepared by dissolving maleimide (13.2 g, 0.136 mol) and N-phenylmaleimide (28.7 g, 0.165 mol) in 73.5 g of MEK was added over 4 hours. ..
Then, the temperature was raised to 80 ° C. and the reaction was further carried out for 3 hours. The reaction mixture was then cooled to room temperature and 133.3 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, further washed with pure water, and then vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 88.3 g, and the yield was 88%. The obtained polymer had a weight average molecular weight Mw of 7,800, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 2.20, and an alkali dissolution rate of 3,600 Å / sec.

(Synthesis Example 8: Synthesis of Polymer 8 (for comparison))
In the reaction vessel, norbornene carboxylic acid (30.7 g, 0.222 mol), N-phenylmaleimide (14.4 g, 0.083 mol), polymerization initiator V-601 (5.1 g, manufactured by Wako Pure Chemical Industries, Ltd.) 0.022 mol) and 20.5 g of MEK were added, and the mixture was stirred and dissolved. Then, after removing the dissolved oxygen in the system by nitrogen bubbling, it was heated. When the internal temperature reached 70 ° C., N-phenylmaleimide (16.4 g, 0.094 mol) and 4-hydroxyphenylmaleimide (8.4 g, 0.044 mol) were added to MEK41.9 g and propylene glycol monomethyl ether 12.6 g. The solution dissolved in the mixed solvent of No. 1 was added over 4 hours.
Then, the temperature was raised to 80 ° C. and the reaction was further carried out for 3 hours. The reaction mixture was then cooled to room temperature and 100 g of MEK was added and diluted. The diluted solution was poured into a large amount of pure water / methanol mixed solution to precipitate the polymer. Then, the polymer was collected by filtration, further washed with pure water, and then vacuum dried at 120 ° C. for 16 hours.
The yield of the obtained polymer was 58.5 g, and the yield was 78%. The obtained polymer had a weight average molecular weight Mw of 5,100, a dispersity (weight average molecular weight Mw / number average molecular weight Mn) of 1.93, and an alkali dissolution rate of 28,800 Å / sec.

A summary of each polymer is shown in the table below.

In the above table, the composition abbreviations are as follows.
NB: 2-norbornene NC: 5-norbornene-2-carboxylic acid MI: maleimide PMI: N-phenylmaleimide CMI: N-cyclohexylmaleimide PhOHMI: N- (4-hydroxyphenyl) maleimide

For the weight average molecular weight (Mw) and the number average molecular weight (Mn) of each polymer, polystyrene-equivalent values obtained from the calibration curve of standard polystyrene (PS) obtained by GPC measurement were used. The measurement conditions are as follows.
Equipment: Gel Permeation Chromatography Equipment manufactured by Tosoh Corporation HLC-8320GPC
Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation
Detector: RI detector for liquid chromatogram Measurement temperature: 40 ° C
Solvent: THF
Sample concentration: 2.0 mg / mL

The alkali dissolution rate of each polymer is a numerical value measured by the following procedure.
(1) First, a solution was prepared in which the obtained polymer was dissolved in a mixed solvent of propylene glycol monomethyl ether acetate: propylene glycol monomethyl ether = 80: 20 (mass ratio) so as to have a solid content of 25% by mass.
(2) The above solution was spin-coated on a silicon wafer and then heat-treated at 100 ° C. for 120 seconds to obtain a polymer film having a film thickness H of 2.0 μm.
(3) The polymer membrane was impregnated with a 0.5% by mass tetramethylammonium hydroxide aqueous solution at 23 ° C., and the time T until the polymer membrane was visually erased was measured. Based on the measured values obtained thereby, the film thickness H / time T was calculated as the dissolution rate (Å / sec).

<Preparation of photosensitive resin composition>
(Example 1)
Polymers 1,4,4'-(1- {4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl} ethylidene) bisphenol and 1,2-naphthoquinone diazide-5 synthesized by Synthesis Example 1 -Esterates with sulfonyl chloride (manufactured by Daito Chemix Co., Ltd .: PA-15), KBM-403 (manufactured by Shinetsu Silicone Co., Ltd.) and F-556 (manufactured by DIC Co., Ltd.) are prepared by mass parts shown in Table 2. , Propylene glycol monomethyl ether acetate (PGMEA): Propylene glycol monomethyl ether (PGME) = 80:20 (mass ratio) dissolved in a mixed solvent so as to have a solid content of 20% by mass. This was filtered through a PTFE filter having a pore size of 0.2 μm to prepare a positive photosensitive resin composition.
(Examples 2 to 6, Comparative Examples 1 to 3)
A positive photosensitive resin composition was prepared in the same manner as in Example 1 except that each component and its amount (part by mass) were as shown in Table 2.
As the novolak resin of Example 6, PR-54919 (m-p-cresol novolak resin manufactured by Sumitomo Bakelite Co., Ltd.) was used.

<Evaluation of photosensitive resin composition>
(Formation of thin film pattern)
A thin film pattern was formed as follows. First, the obtained photosensitive resin composition was rotationally coated on a 4-inch silicon wafer (rotation speed 300 to 2500 rpm), baked on a hot plate at 100 ° C. for 120 seconds, and then a thin film A having a thickness of about 2 μm was obtained. ..
This thin film A was exposed to g / h / i broadband light through a hole pattern mask having a diameter of 10 μm using a g + h + i-line mask aligner (PLA-501F) manufactured by Canon Inc. The exposure amount was 300 mJ / cm ² .
Then, at 23 ° C., a developing treatment was carried out using an aqueous solution of tetramethylammonium hydroxide (TMAH) as a developing solution to obtain a patterned thin film B. The concentration of the developing solution and the developing time are as shown in Table 2 in order to make the conditions suitable for the developing speed of each polymer.
This thin film B was fully exposed to broadband light at 300 mJ / cm ² with PLA-501F and then post-baked by heating on a hot plate at 150 ° C. for 10 minutes to obtain a patterned thin film C.

(Evaluation of residual film ratio (after development and post-baking))
From the film thicknesses of the thin film A, the thin film B, and the thin film C obtained by forming the thin film pattern described above, the residual film ratio was calculated from the following formula.
Residual film ratio after development (%) = [Film thickness of thin film B (μm) / Film thickness of thin film A (μm)] × 100
Post-baking residual film ratio (%) = [thin film C film thickness (μm) / thin film A film thickness (μm)] × 100

(Crack evaluation)
In the above-mentioned thin film pattern formation, it was evaluated whether cracks were observed on the surface of the coating film. The evaluation criteria were the following three-grade evaluation.
3: Good without cracks even after post-baking (thin film C).
2: Cracks are seen after development or post-baking (thin films B and C).
1: Cracks are seen immediately after application of the composition (thin film A).

(Evaluation of developability)
The hole pattern having a diameter of 10 μm after development was evaluated according to the following criteria.
3: No residue was found.
2: Residue was seen, but pattern formation was possible.
1: The film was completely dissolved and the resolution was low, so evaluation was not possible.

(Evaluation of thermal flow resistance)
The hole patterns with a diameter of 10 μm before and after post-baking were evaluated according to the following criteria.
2: No change was seen in the shape.
1: Deformation of the pattern and remarkable changes in the CD (critical dimension) were observed.

(Evaluation of transmittance)
Using a 1737 glass substrate (length 100 mm, width 100 mm) manufactured by Corning Inc., the same operation as described above (formation of a thin film pattern) was performed except that exposure and development were not performed. As a result, a thin film without a pattern was obtained on the glass substrate.
The transmittance (%) of this thin film at a wavelength of 400 nm was measured using an ultraviolet-visible spectrophotometer, and the value converted to a film thickness of 3 μm was taken as the transmittance.

Table 2 summarizes the formulation information of the compositions of each Example and Comparative Example, the information on the developer used, and the evaluation results.

As can be seen from Table 2, the structural unit represented by the general formula (1) (PhOHMI: N- (4-hydroxyphenyl) maleimide) and the structural unit represented by the general formula (2) (NB: 2-norbornene). The photosensitive resin composition containing the polymer containing both of the above has a good residual film ratio (residual film ratio after development and residual film ratio after post-baking), and also shows good results for cracks (Example). 1-6).

In particular, the polymer has additional structural units such as the structural unit (MI: maleimide) represented by the chemical formula (3) and the structural unit (PMI: N-phenylmaleimide) in which R ^c is an aryl group in the general formula (4). ), The developability and thermal flow resistance tended to be excellent.

On the other hand, the photosensitive resin composition containing a polymer containing at least one of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is satisfactory in terms of residual film ratio and cracks. The results were not good (Comparative Examples 1 to 3).

As for the transmittance, all the examples showed high transparency.

Claims (8)

A photosensitive resin composition comprising a polymer containing the structural unit represented by the following general formula (1) and the structural unit represented by the following general formula (2) .
A photosensitive resin composition in which the polymer further contains a structural unit represented by the following chemical formula (3) .

In the general formula (1)
R represents a monovalent substituent and represents
m represents an integer of 1 to 3 and represents
n represents an integer of 0 to 4.
However, m + n is 5 or less.
In the general formula (2)
R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom or a monovalent organic group other than a carboxyl group, respectively.
n represents an integer of 0 to 2.

The photosensitive resin composition according to claim 1.
A photosensitive resin composition comprising a polymer in which the polymer does not contain a structural unit having an oxetanyl group. The photosensitive resin composition according to claim 1 or 2.
A photosensitive resin composition in which the structural unit represented by the general formula (2) contains a structural unit that does not contain a crosslinkable group. The photosensitive resin composition according to any one of claims 1 to 3 .
A photosensitive resin composition in which the structural unit represented by the general formula (1) contains the structural unit represented by the following chemical formula (1-1).

The photosensitive resin composition according to any one of claims 1 to 4 .
A photosensitive resin composition having a weight average molecular weight of 10,000 or more of the polymer. The photosensitive resin composition according to any one of claims 1 to 5 .
Further, a photosensitive resin composition containing a novolak resin. A step of forming a photosensitive resin film using the photosensitive resin composition according to any one of claims 1 to 6 .
A pattern forming method comprising a step of exposing the photosensitive resin film and a step of developing the photosensitive resin film. A method for manufacturing an electronic device, including the pattern forming method according to claim 7 .