JP2024002706A - Photosensitive resin composition, method for producing patterned cured film, patterned cured film, and semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition that offers the capability for fine processing with high resolution and can form a cured film with superior mechanical strength.

SOLUTION: A photosensitive resin composition includes (A) an alkali-soluble resin with a phenolic hydroxy group, (B) a compound with sulfonate at the 4-position, which produces acid upon exposure to light, and (C) a compound with an alkoxy or epoxy group, which induces a crosslinking reaction through heat. Such a photosensitive resin composition has high resolution and superior mechanical strength. The addition of (D) an elastomer may improve both heat resistance and mechanical strength.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a photosensitive resin composition, a method for producing a patterned cured film, a patterned cured film, and a semiconductor element.

In recent years, with the increasing integration and miniaturization of semiconductor devices, interlayer insulating layers of semiconductor devices are required to have not only heat resistance, mechanical properties, and adhesion with metal copper wiring, but also microfabricability, that is, high resolution. Photosensitive resin compositions containing alkali-soluble resins have been developed as materials for forming insulating layers having such characteristics (see, for example, Patent Documents 1 to 4). A resin film is formed by coating and drying these photosensitive resin compositions on a substrate, and a patterned resin film (patterned resin film) is obtained by exposing and developing the resin film. Then, by heating and curing the patterned resin film, a patterned cured film (a patterned cured film) can be formed, and the patterned cured film can be used as an interlayer insulating layer.

JP2008-309885A Japanese Patent Application Publication No. 2007-57595 JP2016-24306A International Publication No. 2010/073948

The photosensitive resin composition used for the interlayer insulating layer is required to have mechanical strength in order to improve microprocessability in accordance with higher wiring densities and connection reliability in accordance with multilayering. In particular, the fine machinability of interlayer insulating layers refers to high resolution and high resolution, and achieving this can be expected to lead to higher density semiconductor packages. However, in conventional photosensitive insulating materials, photosensitive resin compositions with an aspect ratio (in this application, referred to as film thickness/resolution) of 1 or less are common, and for a film thickness of 5 to 7 μm, a resolution of 2 The limit was ~6 μm. In the future, in order to achieve higher integration of semiconductor devices, interlayer insulating materials will be required to have even more microfabricability, and a patterned cured film that exhibits a high resolution of 1 μm, that is, an aspect ratio of 5 or more, will be required.

An object of the present invention is to provide a photosensitive resin composition that can form a cured film that exhibits a high resolution of 1 μm that can be microfabricated and has excellent mechanical strength.

The present disclosure includes the embodiments [1] to [9] below.
[1] (A) an alkali-soluble resin having a phenolic hydroxyl group;
(B) a compound having a sulfonic acid ester at the 4-position that generates an acid when exposed to light;
A photosensitive resin composition containing.
[2] The above (A) alkali-soluble resin having a phenolic hydroxyl group is a compound represented by the following formula (21), a compound represented by the following formula (22), and a compound represented by the following formula (23). The photosensitive resin composition according to item [1], having a structure derived from at least one selected from the group consisting of.

(In the general formula (21), R ²¹ represents a hydrogen atom or a methyl group, and R ²² represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. , a represents an integer from 0 to 3, and b represents an integer from 1 to 3. The sum of a and b is 5 or less.)

(In general formula (22), R ²³ represents a hydrogen atom or a methyl group, and R ²⁴ represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. , c represents an integer of 0 to 3.The alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 10 carbon atoms, or alkoxy group having 1 to 10 carbon atoms represented by R ²⁴ are the same as R ²² , respectively. (This can be exemplified.)

(In general formula (23), R ²⁵ represents a hydrogen atom or a methyl group, and R ²⁶ represents an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms.)
[3] The above (B) compound having a sulfonic acid ester at the 4-position that generates an acid when exposed to light is a condensate of a compound represented by the following formula (b0) and a compound represented by the following formula (b2) The photosensitive resin composition according to item [1] or [2], which is an o-quinonediazide compound containing at least

[4] The photosensitive resin composition according to any one of [1] to [3], further comprising (C) a compound that undergoes a crosslinking reaction when heated.
[5] The photosensitive resin composition according to item [4], wherein the compound (C) that undergoes a crosslinking reaction due to heat is a compound having an alkoxy group or an epoxy group.
[6] (D) The photosensitive resin composition according to any one of [1] to [5], further containing an elastomer.
[7] Applying the photosensitive resin composition according to any one of [1] to [6] on a part or the entire surface of the substrate and drying it to form a resin film;
a step of exposing a part or the entire surface of the resin film;
Developing the exposed resin film with an alkaline aqueous solution to form a patterned resin film;
A method for producing a patterned cured film, comprising the step of heating the patterned resin film.
[8] A patterned cured film having a pattern, the pattern comprising a cured product of the photosensitive resin composition according to any one of [1] to [6].
[9] A semiconductor device comprising the patterned cured film according to [8] as an interlayer insulating layer or a surface protective layer.

According to the present invention, it is possible to provide a photosensitive resin composition that can be microfabricated, exhibits a very high resolution of 1 μm, and can form a patterned cured film having excellent mechanical strength. Further, according to the present invention, it is possible to provide a patterned cured film using the photosensitive resin composition, a method for producing the same, a semiconductor element, and an electronic device.

Embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments. "(Meth)acrylic acid" in this specification means "acrylic acid" or "methacrylic acid", and the same applies to other similar expressions such as (meth)acrylate. In this specification, "solid content" refers to the non-volatile content excluding volatile substances such as water and solvent contained in the photosensitive resin composition. It also includes components that remain in the form of liquid, starch syrup, and wax at room temperature (25°C).

As used herein, the term "step" includes not only independent steps but also steps that cannot be clearly distinguished from other steps as long as the intended effect of the step is achieved. When observed as a plan view, the term "layer" includes a structure having a shape formed on the entire surface as well as a structure having a shape formed in a part of the layer. A numerical range indicated using "~" indicates a range that includes the numerical values written before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this specification, the upper limit or lower limit of the numerical range of one step may be replaced with the upper limit or lower limit of the numerical range of another step. In the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the Examples.

[Photosensitive resin composition]
The photosensitive resin composition according to one embodiment includes (A) an alkali-soluble resin having a phenolic hydroxyl group (hereinafter sometimes referred to as "component (A)"); A compound having a sulfonic acid ester at the position (hereinafter sometimes referred to as "component (B)"). The photosensitive resin composition according to this embodiment can be suitably used as a positive photosensitive resin composition. Hereinafter, the form of the positive photosensitive resin composition will be explained in detail.

<Component (A): Alkali-soluble resin having phenolic hydroxyl group>
In this specification, an alkali-soluble resin means a resin that is soluble in an alkaline aqueous solution (developer). Note that the alkaline aqueous solution is an alkaline solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, a metal hydroxide aqueous solution, or an organic amine aqueous solution. Generally, a TMAH aqueous solution having a concentration of 2.38% by mass is used for development. Whether component (A) is soluble in an alkaline developer can be confirmed, for example, as follows.

A varnish obtained by dissolving a resin in an arbitrary solvent is spin-coated onto a substrate such as a silicon wafer to form a coating film with a thickness of about 5 μm. This is immersed in either a TMAH aqueous solution, a metal hydroxide aqueous solution, or an organic amine aqueous solution at 20 to 25°C. As a result, when the coating can be uniformly dissolved, the resin can be considered soluble in an alkaline developer.

Component (A) may be a resin having a phenolic hydroxyl group from the viewpoint of solubility in an aqueous alkaline solution, high resolution, and mechanical properties.
The phenolic hydroxyl group contained in component (A) may have a structure derived from phenol, o-cresol, m-cresol, or p-cresol.
Component (A) may have a structural unit represented by the following formula (21) as a hydroxystyrene resin to further improve microprocessability and mechanical strength.

[In general formula (21), R ²¹ represents a hydrogen atom or a methyl group, and R ²² represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. , a represents an integer from 0 to 3, and b represents an integer from 1 to 3. The sum of a and b is 5 or less. ]

The hydroxystyrene resin can be obtained by polymerizing monomers that provide the structural unit represented by the general formula (21).
In the general formula (21), the alkyl group having 1 to 10 carbon atoms represented by R ²¹ includes, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a nonyl group. group, decyl group, etc. These groups may be linear or branched. Furthermore, examples of the aryl group having 6 to 10 carbon atoms represented by R ²² include phenyl group and naphthyl group. Examples of the alkoxy group having 1 to 10 carbon atoms represented by ^R21 include methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group, hexoxy group, heptoxy group, octoxy group, nonoxy group, decoxy group, etc. It will be done. These groups may be linear or branched.

Examples of monomers providing the structural unit represented by general formula (21) include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, p-isopropenylphenol, m-isopropenylphenol, o-isopropenyl Examples include phenol. These monomers can be used alone or in combination of two or more.
Hydroxystyrene-based resins are not limited to the manufacturing method, but for example, monomers in which the hydroxyl group of a monomer that provides the structural unit represented by general formula (21) is protected with a t-butyl group, an acetyl group, etc. Then, a monomer with a protected hydroxyl group is polymerized to obtain a polymer, and the obtained polymer is further converted to a hydroxystyrene structural unit by deprotection under an acid catalyst, etc. It can be obtained by deprotection.

The hydroxystyrene resin may be a polymer or copolymer consisting only of a monomer that provides the structural unit represented by the general formula (21), or may be a polymer or copolymer consisting only of a monomer that provides the structural unit represented by the general formula (21). It may also be a copolymer with other monomers. When the hydroxystyrene resin is a copolymer, the proportion of the structural unit represented by general formula (21) in the copolymer is determined to be 100 moles of component (A) from the viewpoint of solubility of the exposed area in an alkaline developer. %, preferably 10 to 100 mol%, more preferably 20 to 97 mol%, even more preferably 30 to 95 mol%, and particularly preferably 50 to 95 mol%.

The hydroxystyrene-based resin is preferably an alkali-soluble resin having a structural unit represented by the following general formula (22) from the viewpoint of further improving the dissolution inhibition property of the unexposed area in an alkaline developer.

[In the general formula (22), R ²³ represents a hydrogen atom or a methyl group, and R ²⁴ represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. , c represents an integer from 0 to 3.
Examples of the alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 10 carbon atoms, or alkoxy group having 1 to 10 carbon atoms represented by R ²⁴ are the same as those for R ²² , respectively. ]

The alkali-soluble resin having the structural unit represented by the general formula (22) can be obtained by using a monomer that provides the structural unit represented by the general formula (22). Examples of monomers providing the structural unit represented by general formula (22) include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-methoxystyrene, m-methoxystyrene. and aromatic vinyl compounds such as p-methoxystyrene. These monomers can be used alone or in combination of two or more.

When the hydroxystyrene resin is an alkali-soluble resin having a structural unit represented by the general formula (22), from the viewpoint of inhibiting dissolution of the unexposed area in an alkaline developer and the mechanical properties of the patterned cured film, the general formula (22) ) is preferably 1 to 90 mol%, more preferably 3 to 80 mol%, even more preferably 5 to 70 mol%, and even more preferably 5 to 50 mol%, based on 100 mol% of component (A). % is particularly preferred.
Further, from the viewpoint of lowering the elastic modulus, the hydroxystyrene resin is preferably an alkali-soluble resin having a structural unit represented by the following general formula (23).

[In general formula (23), R ²⁵ represents a hydrogen atom or a methyl group, and R ²⁶ represents an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms. ]

The alkali-soluble resin having the structural unit represented by the general formula (23) can be obtained by using a monomer that provides the structural unit represented by the general formula (23). Examples of monomers providing the structural unit represented by general formula (23) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and (meth)acrylate. Pentyl acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, hydroxymethyl (meth)acrylate, (meth)acrylate Hydroxyethyl acrylate, Hydroxypropyl (meth)acrylate, Hydroxybutyl (meth)acrylate, Hydroxypentyl (meth)acrylate, Hydroxyhexyl (meth)acrylate, Hydroxyheptyl (meth)acrylate, (meth)acrylic acid Examples include hydroxyoctyl, hydroxynonyl (meth)acrylate, and hydroxydecyl (meth)acrylate. These monomers can be used alone or in combination of two or more.

When the hydroxystyrene resin is an alkali-soluble resin having a structural unit represented by the general formula (23), from the viewpoint of inhibiting dissolution of the unexposed area in an alkaline developer and improving the mechanical properties of the patterned cured film, the general The proportion of the structural unit represented by formula (23) is preferably 1 to 90 mol%, more preferably 3 to 80 mol%, even more preferably 5 to 70 mol%, based on 100 mol% of component (A). Particularly preferred is ~50 mol%.

Phenol resins are polycondensation products of phenol or its derivatives and aldehydes. Polycondensation is usually carried out in the presence of a catalyst such as an acid or a base. The phenolic resin obtained when an acid catalyst is used is particularly called a novolak type phenolic resin. Examples of the novolak type phenolic resin include phenol/formaldehyde novolak resin, cresol/formaldehyde novolak resin, xylenol/formaldehyde novolak resin, resorcinol/formaldehyde novolak resin, phenol-naphthol/formaldehyde novolak resin, and the like.

Examples of the phenol derivatives constituting the phenol resin include o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol. , 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4, Alkylphenols such as 5-trimethylphenol, alkoxyphenols such as methoxyphenol and 2-methoxy-4-methylphenol, alkenylphenols such as vinylphenol and allylphenol, aralkylphenols such as benzylphenol, alkoxycarbonylphenols such as methoxycarbonylphenol, Arylcarbonylphenols such as benzoyloxyphenol, halogenated phenols such as chlorophenol, polyhydroxybenzenes such as catechol, resorcinol, and pyrogallol, bisphenols such as bisphenol A and bisphenol F, naphthol derivatives such as α- or β-naphthol, p- Hydroxyalkyl phenols such as hydroxyphenyl-2-ethanol, p-hydroxyphenyl-3-propanol, and p-hydroxyphenyl-4-butanol, hydroxyalkyl cresols such as hydroxyethyl cresol, monoethylene oxide adducts of bisphenol, and monopropylene of bisphenol. Alcoholic hydroxyl group-containing phenol derivatives such as oxide adducts, p-hydroxyphenylacetic acid, p-hydroxyphenylpropionic acid, p-hydroxyphenylbutanoic acid, p-hydroxycinnamic acid, hydroxybenzoic acid, hydroxyphenylbenzoic acid, hydroxyphenoxybenzoic acid Examples include carboxyl group-containing phenol derivatives such as acids and diphenolic acids. These can be used alone or in combination of two or more.

Examples of the aldehydes constituting the phenol resin include formaldehyde, acetaldehyde, furfural, benzaldehyde, hydroxybenzaldehyde, methoxybenzaldehyde, hydroxyphenylacetaldehyde, methoxyphenylacetaldehyde, crotonaldehyde, chloroacetaldehyde, chlorophenylacetaldehyde, glyceraldehyde, glyoxylic acid, Examples include methyl glyoxylate, phenyl glyoxylate, hydroxyphenyl glyoxylate, formylacetic acid, methyl formylacetate, 2-formylpropionic acid, methyl 2-formylpropionate, and the like. These can be used alone or in combination of two or more. In addition, formaldehyde precursors such as paraformaldehyde and trioxane, ketones such as acetone, pyruvic acid, levulinic acid, 4-acetylbutyric acid, acetonedicarboxylic acid, and 3,3'-4,4'-benzophenonetetracarboxylic acid are May be used in reactions.

The weight average molecular weight (Mw) of component (A) is preferably 1,000 to 500,000, more preferably 2,000 to 200,000, considering the balance between solubility in aqueous alkaline solutions, photosensitive properties, and mechanical properties of the patterned cured film. , more preferably from 2,000 to 100,000. Here, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) and converted from a standard polystyrene calibration curve.

<Component (B): Compound having a sulfonic acid ester at the 4-position that generates acid when exposed to light>
Component (B), a compound having a sulfonic acid ester at the 4-position that generates an acid when exposed to light (by receiving light), functions as a photosensitizer in the photosensitive resin composition. Component (B) has the function of generating an acid upon irradiation with light and increasing the solubility of the irradiated portion in an alkaline aqueous solution. As component (B), a compound generally referred to as a photoacid generator can be used. Component (B) includes, for example, o-quinonediazide compounds, aryldiazonium salts, diaryliodonium salts, and triarylsulfonium salts. Component (B) may be composed of only one kind of these compounds, or may be composed of two or more kinds. Among these, component (B) may be an o-quinonediazide compound because of its high sensitivity.
As the o-quinonediazide compound, for example, one obtained by subjecting o-quinonediazide sulfonyl chloride and a hydroxy compound and/or an amino compound to a condensation reaction in the presence of a dehydrochlorination agent can be used.
Examples of o-quinonediazide sulfonyl chloride include benzoquinone-1,2-diazide-4-sulfonyl chloride, naphthoquinone-1,2-diazide-5-sulfonyl chloride, and naphthoquinone-1,2-diazide-6-sulfonyl chloride. Can be mentioned.

Examples of hydroxy compounds include hydroquinone, resorcinol, pyrogallol, bisphenol A, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl) )-1-methylethyl}phenyl]ethane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2 , 2',4,4'-tetrahydroxybenzophenone, 2,3,4,2',3'-pentahydroxybenzophenone, 2,3,4,3',4',5'-hexahydroxybenzophenone, bis( 2,3,4-trihydroxyphenyl)methane, bis(2,3,4-trihydroxyphenyl)propane, 4b,5,9b,10-tetrahydro-1,3,6,8-tetrahydroxy-5,10 -dimethylindeno[2,1-a]indene, tris(4-hydroxyphenyl)methane, and tris(4-hydroxyphenyl)ethane.

Examples of amino compounds include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl sulfide. , o-aminophenol, m-aminophenol, p-aminophenol, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, bis(3- Amino-4-hydroxyphenyl)propane, bis(4-amino-3-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(4-amino-3-hydroxyphenyl)sulfone, bis( Examples include 3-amino-4-hydroxyphenyl)hexafluoropropane and bis(4-amino-3-hydroxyphenyl)hexafluoropropane.

Among these, 1,1-bis(4-hydroxy condensate of phenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane and 1-naphthoquinone-2-diazide-5-sulfonyl chloride, 1,1-bis( Condensation product of 4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane and 1-naphthoquinone-2-diazido-4-sulfonyl chloride, tris(4 - Condensates of hydroxyphenyl)methane or tris(4-hydroxyphenyl)ethane and 1-naphthoquinone-2-diazide-5-sulfonyl chloride, tris(4-hydroxyphenyl)methane or tris(4-hydroxyphenyl)ethane and It may also be a condensate with 1-naphthoquinone-2-diazide-4-sulfonyl chloride.

Component (B1): A condensate of a compound represented by the following formula (b0) and a compound represented by the following formula (b1).
Component (B2): A condensate of a compound represented by the following formula (b0) and a compound represented by the following formula (b2).
b0: 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}
b1: 1-naphthoquinone-2-diazido-5-sulfonyl chloride b2: 1-naphthoquinone-2-diazido-4-sulfonyl chloride

Examples of the dehydrochlorination agent include sodium carbonate, sodium hydroxide, sodium hydrogen carbonate, potassium carbonate, potassium hydroxide, trimethylamine, triethylamine, and pyridine.

When blending o-quinonediazide sulfonyl chloride with a hydroxy compound and/or an amino compound, the total number of moles of hydroxyl groups and amino groups is 0.5 to 1.0 per 1 mole of o-quinonediazide sulfonyl chloride. It is preferable to mix them in molar amounts. A preferred blending ratio of the dehydrochloric agent and o-quinonediazide sulfonyl chloride is in the range of 0.95/1.00 mol to 1.00/0.95 mol equivalent.
The preferred reaction temperature for the above reaction is 0 to 40°C, and the preferred reaction time is 1 to 10 hours. As the reaction solvent, for example, dioxane, acetone, methyl ethyl ketone, tetrahydrofuran, diethyl ether, or N-methylpyrrolidone is used.

The content of component (B) is 1 to 50 parts by mass, and 3 to 50 parts by mass per 100 parts by mass of component (A), from the viewpoint of increasing the dissolution rate difference between exposed and unexposed areas and improving sensitivity. It may be 35 parts by weight, or 5 to 20 parts by weight.

<(C) component: thermal crosslinking agent>
The photosensitive resin composition of this embodiment may further contain a thermal crosslinking agent as component (C). Component (C) is a compound having a structure that can react with component (A) to form a bridged structure when heating and curing the patterned resin film. This can prevent the film from becoming brittle and from melting. Component (C) includes, for example, a compound having a phenolic hydroxyl group, a compound having an alkoxy group, and a compound having an epoxy group.

The "compound having a phenolic hydroxyl group" as used herein does not include component (A). A compound having a phenolic hydroxyl group as a thermal crosslinking agent not only functions as a thermal crosslinking agent, but also increases the dissolution rate of the exposed area during development with an alkaline aqueous solution, thereby improving sensitivity. The weight average molecular weight (Mw) of such a compound having a phenolic hydroxyl group may be 3000 or less, 2000 or less, or 1500 or less, taking into consideration the balance of solubility in an aqueous alkaline solution, photosensitivity, and mechanical strength.

As the compound having an alkoxy group, known compounds can be used. The compound having an alkoxy group may have a methoxy group, and may have four or more methoxy groups, since it can impart high reactivity and heat resistance. The compound having an alkoxy group has an excellent balance between the effect of promoting dissolution in the exposed area and the mechanical strength of the cured film, and therefore may be a compound selected from the compounds represented by the following formula.

As the compound having an epoxy group, known compounds can be used. Examples of compounds having an epoxy group include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, alicyclic epoxy compounds, glycidylamine type epoxy compounds, and heterocyclic epoxy compounds. compounds, halogenated epoxy compounds, and polyalkylene glycol diglycidyl ethers.

In addition to the above-mentioned compounds, component (C) may include hydroxyl compounds such as bis[3,4-bis(hydroxymethyl)phenyl]ether, 1,3,5-tris(1-hydroxy-1-methylethyl)benzene Aromatic compounds with a methyl group, compounds with a maleimide group such as bis(4-maleimidophenyl)methane, 2,2-bis[4-(4'-maleimidophenoxy)phenyl]propane, compounds with a norbornene skeleton, etc. It is also possible to use functional acrylate compounds, compounds with oxetanyl groups, compounds with vinyl groups, or blocked isocyanate compounds.
The content of component (C) is 1 to 70 parts by mass, 2 to 50 parts by mass, or 3 to 40 parts by mass based on 100 parts by mass of component (A) from the viewpoint of heat resistance of the cured film and warpage of the coated substrate. It may be a department.

<(D) Component: Elastomer>
The resin composition of this embodiment may further contain an elastomer as component (D) from the viewpoint of improving the flexibility of the patterned cured film. Component (D) includes, for example, styrene elastomer, olefin elastomer, urethane elastomer, polyester elastomer, polyamide elastomer, acrylic elastomer, and silicone elastomer. These can be used alone or in combination of two or more. Furthermore, a skeleton of an elastomer component may be introduced into the component (A).

The acrylic elastomer may have a structural unit represented by the following formula (8). By having the structural unit represented by the following formula (8), the acrylic elastomer improves the compatibility between the components (A) and (D), thereby sufficiently suppressing clouding of the photosensitive resin composition. The haze value of the patterned cured film can be lowered, and the mechanical strength can be further improved.

[In formula (8), R ¹⁷ represents a hydrogen atom or a methyl group, and R ¹⁸ represents a hydroxyalkyl group having 2 to 20 carbon atoms. ]

Examples of the hydroxyalkyl group having 2 to 20 carbon atoms represented by R ¹⁸ include hydroxyethyl group, hydroxypropyl group, hydroxybutyl group, hydroxypentyl group, hydroxyhexyl group, hydroxyheptyl group, hydroxyoctyl group, and hydroxynonyl group. , hydroxydecyl group, hydroxyundecyl group, hydroxydodecyl group (sometimes referred to as hydroxylauryl group), hydroxytridecyl group, hydroxytetradecyl group, hydroxypentadecyl group, hydroxyhexadecyl group, hydroxyheptadecyl group, hydroxy Examples include octadecyl group, hydroxynonadecyl group, and hydroxyeicosyl group. These groups may be linear or branched.

In formula (8), from the viewpoint of further improving compatibility with component (A) and mechanical strength, R ¹⁸ is preferably a hydroxyalkyl group having 2 to 15 carbon atoms, and a hydroxyalkyl group having 2 to 10 carbon atoms. More preferred is a hydroxyalkyl group having 2 to 8 carbon atoms.

Examples of monomers providing the structural unit represented by formula (8) include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, Hydroxyhexyl (meth)acrylate, Hydroxyheptyl (meth)acrylate, Hydroxyoctyl (meth)acrylate, Hydroxynonyl (meth)acrylate, Hydroxydecyl (meth)acrylate, Hydroxyundecyl (meth)acrylate, ( Hydroxydodecyl (meth)acrylate (sometimes referred to as hydroxylauryl (meth)acrylate), Hydroxytridecyl (meth)acrylate, Hydroxytetradecyl (meth)acrylate, Hydroxypentadecyl (meth)acrylate, (Meth) ) hydroxyhexadecyl acrylate, hydroxyheptadecyl (meth)acrylate, hydroxyoctadecyl (meth)acrylate, hydroxynonadecyl (meth)acrylate, and hydroxyeicosyl (meth)acrylate. These monomers can be used alone or in combination of two or more.

Among these, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, ( Hydroxypentyl (meth)acrylate, Hydroxyhexyl (meth)acrylate, Hydroxyheptyl (meth)acrylate, Hydroxyoctyl (meth)acrylate, Hydroxynonyl (meth)acrylate, Hydroxydecyl (meth)acrylate, (meth) It is preferable to use hydroxyundecyl acrylate or hydroxydodecyl (meth)acrylate.

Component (D) may be an acrylic elastomer consisting only of the structural unit represented by formula (8), or an acrylic elastomer having a structural unit other than the structural unit represented by formula (8). Good too. In the case of an acrylic resin having a structural unit other than the structural unit represented by formula (8), the proportion of the structural unit represented by formula (8) in the acrylic resin is as follows: It may be 0.1 to 30.0 mol%, 0.3 to 20.0 mol%, or 0.5 to 10.0 mol%.
The acrylic elastomer may further have a structural unit represented by the following formula (9).

[In formula (9), R ¹⁹ represents a hydrogen atom or a methyl group, and R ²⁰ represents a monovalent organic group having a primary, secondary, or tertiary amino group. ]

When the component (D) has a structural unit represented by formula (9), it is possible to further improve the dissolution inhibiting property of the unexposed area in the developer and the adhesion to the metal substrate.
Examples of monomers that provide an acrylic elastomer having a structural unit represented by formula (9) include aminoethyl (meth)acrylate, N-methylaminoethyl (meth)acrylate, and N,N-dimethylaminoethyl (meth)acrylate. Acrylate, N-ethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, aminopropyl (meth)acrylate, N-methylaminopropyl (meth)acrylate, N,N-dimethylaminopropyl (meth) Acrylate, N-ethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate, piperidin-4-yl (meth)acrylate, 1-methylpiperidin-4-yl (meth)acrylate, 2,2, 6,6-tetramethylpiperidin-4-yl (meth)acrylate, 1,2,2,6,6-pentamethylpiperidin-4-yl (meth)acrylate, (piperidin-4-yl)methyl (meth)acrylate , and 2-(piperidin-4-yl)ethyl (meth)acrylate. These monomers can be used alone or in combination of two or more.

Among these, from the viewpoint of further improving the adhesion of the patterned cured film to the substrate and the compatibility with the component (A), ^R20 in formula (9) is a monovalent compound represented by the following formula (10). An organic group is preferred.

[In formula (10), Y represents an alkylene group having 1 to 5 carbon atoms, and R ²¹ , R ²² , R ²³ , R ²⁴ , and R ²⁵ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. , and e represents an integer from 0 to 10. ]

In formula (9), monomers that provide a structural unit in which R ²⁰ is a monovalent organic group represented by formula (10) include, for example, piperidin-4-yl (meth)acrylate, 1-methylpiperidine -4-yl (meth)acrylate, 2,2,6,6-tetramethylpiperidin-4-yl (meth)acrylate, 1,2,2,6,6-pentamethylpiperidin-4-yl (meth)acrylate , (piperidin-4-yl)methyl (meth)acrylate, and 2-(piperidin-4-yl)ethyl (meth)acrylate. Among these, 1,2,2,6,6-pentamethylpiperidin-4-yl methacrylate is designated as FA-711MM, and 2,2,6,6-tetramethylpiperidin-4-yl methacrylate is designated as FA-712HM. (both manufactured by Showa Denko Materials Co., Ltd., trade names) are preferred because they are commercially available.

When component (D) has a structural unit represented by formula (10), the proportion of the structural unit represented by formula (9) is determined from the viewpoint of compatibility with component (A) and solubility in a developer. , preferably from 0.3 to 10.0 mol%, more preferably from 0.4 to 6.0 mol%, and from 0.5 to 5.0 mol%, based on the total amount of component (D). % is more preferable.
The acrylic elastomer may further have a structural unit represented by the following formula (11). When the acrylic elastomer has a structural unit represented by formula (11), the thermal shock resistance of the cured film can be further improved.

[In formula (11), R ²⁶ represents a hydrogen atom or a methyl group, and R ²⁷ represents an alkyl group having 4 to 20 carbon atoms. ]

Examples of the alkyl group having 4 to 20 carbon atoms represented by R ²⁷ include butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group (also referred to as lauryl group). ), tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and eicosyl group. These groups may be linear or branched.

In formula (11), from the viewpoint of alkali solubility, thermal shock resistance, and compatibility with component (A), R ²⁷ is preferably an alkyl group having 4 to 16 carbon atoms; It is more preferably a group, and even more preferably an alkyl group having 4 carbon atoms (n-butyl group).

Examples of the monomer represented by formula (11) include butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, ( Nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (sometimes referred to as lauryl (meth)acrylate), tridecyl (meth)acrylate, (meth)acrylate Examples include tetradecyl acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate. These monomers can be used alone or in combination of two or more.

Among these, from the viewpoint of further improving the elongation at break and lowering the elastic modulus, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, and (meth)acrylate are used. It is preferable to use octyl acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, or dodecyl (meth)acrylate (also referred to as lauryl (meth)acrylate).

When component (D) has a structural unit represented by formula (11), the proportion of the structural unit represented by formula (11) is 50 to 93 mol% with respect to the total amount of component (D). The amount is preferably from 55 to 85 mol%, and even more preferably from 60 to 80 mol%. When the proportion of the structural unit represented by the above formula (11) is 50 to 93 mol%, the thermal shock resistance of the cured film can be further improved.

The acrylic elastomer may further have a structural unit represented by the following formula (12). When the acrylic elastomer has the structural unit represented by formula (12), the alkali solubility of the exposed portion of the resin film can be further improved.

[In formula (12), R ²⁸ represents a hydrogen atom or a methyl group. ]

Examples of monomers that provide the structural unit represented by formula (12) include acrylic acid and methacrylic acid.
When component (D) has a structural unit represented by formula (12), the proportion of the structural unit represented by formula (12) is 5 to 35 mol% with respect to the total amount of component (D). The amount is preferably from 10 to 30 mol%, and even more preferably from 15 to 25 mol%. When the composition ratio of the structural unit represented by the above formula (12) is 5 to 35 mol %, the compatibility with component (A) and the alkali solubility of the exposed area can be further improved.

Acrylic elastomers include, for example, a monomer that provides a structural unit represented by the above formula (8), and a structural unit that is added as necessary and is represented by a formula (9), (11), or (12). It is obtained by blending monomers, stirring in a solvent such as ethyl lactate, toluene, isopropanol, etc., and heating if necessary.

The monomers used to synthesize the acrylic elastomer may further contain monomers other than the monomers providing the structural units represented by formulas (8), (9), (11), and (12).

Such monomers include, for example, N-(meth)acryloyloxyethylhexahydrophthalimide, 1,4-cyclohexanedimethanol mono(meth)acrylate, benzyl (meth)acrylate, and 4-methylbenzyl (meth)acrylate. , acrylonitrile, vinyl alcohol esters such as vinyl-n-butyl ether, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2, 3,3-Tetrafluoropropyl (meth)acrylate, α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β-furyl (meth)acrylic acid, β-styryl (meth)acrylic acid, maleic acid , maleic acid anhydride, maleic acid monoesters such as monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. . These monomers can be used alone or in combination of two or more.

The weight average molecular weight (Mw) of component (D) may be 2,000 to 100,000, 3,000 to 60,000, 5,000 to 50,000, or 10,000 to 40,000. When Mw is 2,000 or more, the thermal shock resistance of the cured film can be further improved, and when it is 100,000 or less, compatibility with component (A) and developability can be further improved.

The content of component (D) is determined to be 100 parts by mass of component (A) from the viewpoint of the balance of alkali solubility in the exposed area, alkali dissolution inhibition in the unexposed area, adhesion to the metal substrate, and thermal shock resistance. The amount may be 1 to 50 parts by weight, 2 to 30 parts by weight, or 3 to 20 parts by weight.

<Other ingredients>
The photosensitive resin composition of this embodiment may contain, in addition to the above-mentioned components (A) to (D), an adhesion aid that improves adhesion to the substrate. Furthermore, components such as a solvent, a compound that generates an acid upon heating, a dissolution promoter, a dissolution inhibitor, a coupling agent, a surfactant, and a leveling agent may be contained.

(solvent)
By containing a solvent, the photosensitive resin composition of the present embodiment has the advantage that it can be easily applied onto a substrate and can form a coating film with a uniform thickness. Examples of the solvent include γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, benzyl acetate, n-butyl acetate, ethoxyethyl propionate, 3-methylmethoxypropionate, N-methyl-2-pyrrolidone, N , N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphorylamide, tetramethylene sulfone, diethyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol Monobutyl ether and dipropylene glycol monomethyl ether are mentioned. One type of solvent can be used alone or two or more types can be used in combination. Among these, it is preferable to use ethyl lactate or γ-butyrolactone from the viewpoint of solubility and uniformity of the coating film.

(adhesion aid)
The photosensitive resin composition of this embodiment may contain an adhesion aid. By containing the adhesion aid, it is possible to provide a photosensitive resin composition having a patterned cured film with good adhesion to the substrate. The adhesion aid may contain a nitrogen-containing aromatic compound represented by the following formula (7).

[In formula (7), R ⁵¹ represents a hydrogen atom or a hydrocarbon group, and R ⁵² represents a hydrogen atom, an amino group, or a phenyl group. A and B each independently represent a nitrogen atom, or a carbon atom and a hydrogen atom (CH) bonded thereto. ]

The nitrogen-containing aromatic compound represented by the formula (7) may be a nitrogen-containing aromatic compound represented by the following formula (7a) from the viewpoint of further improving the adhesion to the substrate. R ⁵² in formula (7a) has the same meaning as R ⁵² in formula (7).

Component (E) includes, for example, 1H-tetrazole, 5-aminotetrazole, 5-phenyltetrazole, and 5-methyltetrazole. Among these, component (E) may include 1H-tetrazole or 5-aminotetrazole from the viewpoint of providing better adhesion to the substrate.
From the viewpoint of providing good adhesion to the substrate and sensitivity, the blending amount of component (E) is 0.01 to 20 parts by mass, 0.015 to 10 parts by mass, per 100 parts by mass of component (A), Or it may be 0.02 to 7 parts by mass.

(Compound that generates acid when heated)
In one form of the present application, by using a compound that generates an acid when heated, it is possible to generate an acid when heating a patterned resin film, and the reaction between the (A) component and the (C) component, that is, the heat The crosslinking reaction is promoted and the heat resistance of the patterned cured film is improved.
In addition, the compound used in another embodiment of the present application that generates an acid when heated also generates an acid when irradiated with light, so that the solubility of the exposed portion in the alkaline aqueous solution increases. Therefore, the difference in solubility in an alkaline aqueous solution between the unexposed area and the exposed area is further increased, and resolution can be further improved.

The compound that generates an acid when heated is preferably one that generates an acid when heated at a temperature of 50 to 250°C, for example. Examples of compounds that generate acids upon heating include salts formed from strong acids and bases such as onium salts, and imidosulfonates. When using a compound that generates an acid upon heating, the content is 0.1 to 30.0 parts by mass, 0.2 to 20.0 parts by mass, or 0.5 parts by mass relative to 100 parts by mass of component (A). It may be 10.0 parts by mass.

(Solubility promoter)
By blending a dissolution promoter into the above-mentioned positive photosensitive resin composition, it is possible to increase the dissolution rate of exposed areas during development with an alkaline aqueous solution and improve sensitivity and resolution. As the solubility promoter, known ones can be used. Examples of the solubility promoter include compounds having a carboxy group, a sulfo group, or a sulfonamide group. When using a dissolution promoter, the content can be determined depending on the rate of dissolution in the alkaline aqueous solution, and can be, for example, 0.01 to 30 parts by mass relative to 100 parts by mass of component (A).

(dissolution inhibitor)
The dissolution inhibitor is a compound that inhibits the solubility of component (A) in an alkaline aqueous solution, and is used to control the remaining film thickness, development time, and contrast. Dissolution inhibitors include, for example, diphenyliodonium nitrate, bis(p-tert-butylphenyl)iodonium nitrate, diphenyliodonium bromide, diphenyliodonium chloride, and diphenyliodonium iodide. When using a dissolution inhibitor, the content is 0.01 to 20 parts by mass, 0.01 to 15 parts by mass, or 0.01 to 15 parts by mass, based on 100 parts by mass of component (A), from the viewpoint of sensitivity and development time tolerance. It may be from .05 to 10 parts by weight.

(coupling agent)
By blending a coupling agent into the photosensitive resin composition, the adhesiveness of the formed patterned cured film to the substrate can be further improved. Examples of the coupling agent include organic silane compounds and aluminum chelate compounds.
Examples of the organic silane compound include KBM-403, KBM-803, and KBM-903 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name). When using a coupling agent, the content may be 0.1 to 20.0 parts by weight or 0.5 to 10.0 parts by weight based on 100 parts by weight of component (A).

(Surfactant or leveling agent)
By incorporating a surfactant or a leveling agent into the photosensitive resin composition, the applicability can be further improved. Specifically, for example, by containing a surfactant or a leveling agent, striations (unevenness in film thickness) can be further prevented and developability can be further improved. Such surfactants or leveling agents include, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene octylphenol ether. Commercially available products include, for example, Megafac F-171, F-565, and RS-78 (manufactured by DIC Corporation, trade name).
When using a surfactant or a leveling agent, the content may be 0.001 to 5 parts by weight or 0.01 to 3 parts by weight based on 100 parts by weight of component (A).

The photosensitive resin composition of this embodiment can be developed using an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH).

[Patterned cured film and method for producing patterned cured film]
The patterned cured film according to one embodiment has a pattern, and the pattern includes a cured product of the above-described photosensitive resin composition. The patterned cured film is obtained by heating the above-mentioned photosensitive resin composition. Hereinafter, a method for manufacturing a patterned cured film will be described.

The method for producing a patterned cured film according to the present embodiment includes a step of applying the above-described photosensitive resin composition to a part or the entire surface of a substrate and drying it to form a resin film (coating/drying (film forming) step); A step of exposing a part or the entire surface of the resin film (exposure step), a step of developing the exposed resin film with an alkaline aqueous solution to form a patterned resin film (developing step), and a step of heating the patterned resin film ( heat treatment step). Each step will be explained below.

(Coating/drying (film formation) process)
First, the photosensitive resin composition of this embodiment is applied onto a substrate and dried to form a resin film. In this step, the photosensitive resin composition of this embodiment is spin-coated onto a substrate such as a glass substrate, a semiconductor, a metal oxide insulator (e.g., TiO ₂ , SiO ₂ ), silicon nitride, etc. using a spinner or the like. and forms a coating film. The thickness of the coating film is not particularly limited, but may be 0.1 to 40 μm. The substrate on which this coating film is formed is dried using a hot plate, an oven, or the like. The drying temperature and drying time are not particularly limited, but may be 80 to 140°C for 1 to 7 minutes. As a result, a resin film is formed on the substrate. The thickness of the resin film is not particularly limited, but may be 0.1 to 40 μm.

(Exposure process)
Next, in the exposure step, the resin film formed on the substrate is irradiated with actinic rays such as ultraviolet rays, visible rays, and radiation through a mask. In the photosensitive resin composition of the present embodiment, component (A) has high transparency to g, h, and i lines, so any or all of the g, h, and i lines can be used for exposure.

(Developing process)
In the development step, the resin film is patterned by removing the exposed portion of the resin film after the exposure step with a developer, and a patterned resin film is obtained. As the developer, for example, an alkaline aqueous solution such as sodium carbonate, sodium hydroxide, potassium hydroxide, sodium silicate, ammonia, ethylamine, diethylamine, triethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), etc. is preferably used. It will be done. The base concentration of these aqueous solutions may be 0.1 to 10.0% by weight. Alcohols or surfactants may also be added to the developer. Each of these may be blended in an amount of 0.01 to 10.0 parts by weight or 0.1 to 5.0 parts by weight per 100 parts by weight of the developer. When developing using a developer, for example, the resin film is filled with the developer by a method such as shower development, spray development, immersion development, paddle development, etc., and the temperature is 30 to 40 degrees Celsius. Leave for 360 seconds. After being left to stand, the patterned resin film is washed and dried by washing with water and spin drying.

(heat treatment process)
Next, in the heat treatment step, a patterned cured film can be formed by heat-treating the patterned resin film. The heating temperature in the heat treatment step may be 300° C. or lower, 270° C. or lower, or 250° C. or lower, from the viewpoint of sufficiently preventing heat damage to the semiconductor device.

The heat treatment can be performed using an oven such as a quartz tube furnace, a hot plate, a rapid thermal annealing, a vertical diffusion furnace, an infrared heating furnace, an electron beam irradiation device, a microwave irradiation device, or the like. Further, although either the air or an inert gas atmosphere such as nitrogen can be selected, it is preferable to perform the heat treatment in an inert gas atmosphere because oxidation of the patterned resin film can be prevented. Since the heating temperature range described above is lower than the conventional heating temperature, thermal damage to the supporting substrate and the semiconductor device can be suppressed to a small level.
Therefore, by using the method for manufacturing a patterned cured film according to this embodiment, electronic devices can be manufactured with high yield. It also leads to energy savings in the process. Furthermore, according to the positive photosensitive resin composition of the present embodiment, the volumetric shrinkage (curing shrinkage) during the heat treatment step, which is observed in photosensitive polyimides, is small, so that deterioration in dimensional accuracy can be prevented.
The heat treatment time in the heat treatment step may be any time sufficient to cure the positive photosensitive resin composition, and is preferably set to approximately 5 hours or less in view of work efficiency.

The heat treatment can also be performed using a microwave irradiation device or a frequency variable microwave irradiation device in addition to the above-mentioned oven. By using these devices, it is possible to effectively heat only the resin film while keeping the temperature of the substrate and semiconductor device at a desired temperature (for example, 200° C. or lower) (J. Photopolym. Sci. Technol., 18, 327-332 (2005)).

The patterned cured film according to this embodiment can be used as an interlayer insulating layer and a surface protective layer of a semiconductor element. A semiconductor element including an interlayer insulating layer and a surface protective layer formed from a cured film of the above-described photosensitive resin composition, and an electronic device including the semiconductor element can be produced. The semiconductor device may be, for example, a memory, a package, etc., having a multilayer wiring structure, a rewiring structure, or the like. Examples of electronic devices include mobile phones, smartphones, tablet terminals, personal computers, and hard disk suspensions. By providing a patterned cured film formed from the photosensitive resin composition of this embodiment, it is possible to provide a semiconductor element and an electronic device with excellent reliability.

The present invention will be specifically explained below based on Examples, but the present invention is not limited thereto.

The materials used in Examples and Comparative Examples are shown below.
((A) component)
A1: copolymer of 4-hydroxystyrene/styrene = 85/15 (mole ratio) (weight average molecular weight (Mw) = 30,000, manufactured by Gunei Chemical Industry Co., Ltd., product name "Resitop")
A2: 4-hydroxystyrene/styrene = 85/15 (mole ratio) copolymer (weight average molecular weight (Mw) = 10,000, manufactured by Maruzen Petrochemical Co., Ltd., trade name "Maruka Linker CST")
A3: 4-hydroxystyrene/styrene = 70/30 (mole ratio) copolymer (weight average molecular weight (Mw) = 10,000, manufactured by Maruzen Petrochemical Co., Ltd., trade name "Maruka Linker CST")
The weight average molecular weight (Mw) was determined in terms of standard polystyrene using gel permeation chromatography (GPC).

Specifically, the weight average molecular weight (Mw) was measured using the following apparatus and conditions.
Measuring device Detector: L4000UV manufactured by Hitachi, Ltd.
Pump: L6000 manufactured by Hitachi, Ltd.
Column: Hitachi High-Tech Corporation Gelpack GL-S300MDT-5 x 2 Measurement conditions Eluent: Tetrahydrofuran (THF)
LiBr (0.03mol/L), _H3PO4 ( _0.06mol /L)
Flow rate: 1.0mL/min, detector: UV270nm
The measurement was performed using a solution of 1 mL of solvent [THF/DMF=1/1 (volume ratio)] for 0.5 mg of sample.

((B) component)
B1: 1-naphthoquinone-2-diazido-5-sulfonic acid of 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane Ester (esterification rate approximately 90%, manufactured by Daito Chemix Co., Ltd., product name "PA28")
B2: 1-naphthoquinone-2-diazido-4-sulfonic acid of 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane Ester (manufactured by Daito Chemix Co., Ltd., product name "4C-PA-28")

((C) component)
C1: 4,4'-[1-[4-[1-[4-hydroxy-3,5-bis(methoxymethyl)phenyl]-1-methylethyl]phenyl]ethylidene]bis[2,6-bis( methoxymethyl)phenol] (manufactured by Honshu Chemical Industry Co., Ltd., product name "HMOM-TPPA")
C2: Hexakis(methoxymethyl)melamine (manufactured by Sanwa Chemical Co., Ltd., trade name "Nicalac MW-30HM")

((D) component)
D1: In a 100 mL three-neck flask equipped with a stirrer, a nitrogen inlet tube, and a thermometer, 55 g of ethyl lactate was weighed, and 34 g of a polymerizable monomer (n-butyl acrylate (BA)) weighed separately. 7g, lauryl acrylate (LA) 2.2g, acrylic acid (AA) 3.9g, hydroxybutyl acrylate (HBA) 2.6g, 1,2,2,6,6-pentamethylpiperidin-4-yl methacrylate (Product name: FA-711MM, manufactured by Showa Denko Materials Co., Ltd.) 1.7 g and azobisisobutyronitrile (AIBN) 0.29 g were added. Stirring at room temperature (25°C) for about 160 min ^-1 Dissolved oxygen was removed by flowing nitrogen gas at a flow rate of 400 mL/min for 30 minutes while stirring at the rotational speed.After that, the flow of nitrogen gas was stopped, the flask was sealed, and the temperature was increased to 65°C for about 25 minutes in a constant temperature water bath. The temperature was maintained at the same temperature for 10 hours to carry out a polymerization reaction to obtain D1, which is an acrylic resin.The polymerization rate at this time was 99%.The weight average molecular weight (Mw) of D1 was approximately The molar ratio of the polymerizable monomers in D1 was as follows.
BA/LA/AA/HBA/FA711MM=69/2/20/5/4 (mol%)

(Examples 1 to 7)
Components (A), (B), and (C) in the amounts shown in Table 1 were blended with ethyl lactate as a solvent, and this was filtered under pressure using a polytetrafluoroethylene filter with 0.2 μm pores. , a photosensitive resin composition was prepared.

(Comparative Examples 1 to 3)
A photosensitive resin composition was prepared in the same manner as in the example except that components (A), (B), and (C) were used in the amounts shown in Table 2.

[Evaluation of photosensitive resin composition]
(exterior)
The appearance of the photosensitive resin composition was visually observed, and if it was transparent it was rated "A", if it was slightly cloudy it was rated "B", and if it was extremely cloudy it was rated "C". If the appearance judgment of the photosensitive resin composition is "A" or "B", the position marked on the substrate when manufacturing a semiconductor device having a patterned cured film formed using the photosensitive resin composition. Marks for alignment can be visually recognized.

(Remaining film rate after development)
The residual film rate after development was calculated by the following formula from the thickness of the resin film before development and the thickness of the pattern film after development.
Remaining film rate after development (%) = (thickness of pattern film after development/thickness of resin film before development) x 100
When the residual film rate after development is large, the amount of unexposed areas dissolved by the alkaline developer can be reduced. Therefore, the latitude in adjusting the exposure amount necessary for dissolving the exposed portion is improved. That is, in a positive photosensitive resin composition, the dissolution contrast is improved, so high resolution can be achieved.

(resolution)
The photosensitive resin composition was spin-coated onto a silicon substrate and heated at 120° C. for 3 minutes to form a coating film with a thickness of 6 to 8 μm. Next, using an i-line stepper (manufactured by Canon Inc., trade name "FPA-3000iW"), reduction projection exposure was performed with i-line (365 nm) through a mask having a hole pattern of 1 μm to 100 μm. The exposure amount was 100 mJ/cm ² to 1500 mJ/cm ² . After exposure, it was developed using a 2.38% TMAH aqueous solution and rinsed with water to obtain a patterned resin film.
The patterned resin film was heated in a nitrogen atmosphere from room temperature (25°C) to 230°C over 1 hour using an inert gas oven (manufactured by Koyo Thermo Systems Co., Ltd., product name "INH-9CD-S"). Heat treatment was performed for 2 hours while maintaining the temperature to produce a patterned cured film for resolution evaluation with a film thickness of approximately 5 μm. The minimum open size of the hole pattern from 1 μm to 100 μm in the patterned cured film was defined as the resolution of microfabrication. The smaller the opening pattern size, the better the resolution and the more fine processing becomes possible.

(Elongation at break, strength at break)
The photosensitive resin composition was spin-coated onto a silicon substrate and heated at 120° C. for 4 minutes to form a coating film with a thickness of about 11 to 12 μm. Thereafter, this coating film was exposed to light at all wavelengths at 1000 mJ/cm ² through a mask using a proximity exposure machine (manufactured by Canon Inc., trade name "PLA-600FA"). After exposure, development was performed using a 2.38% aqueous solution of TMAH to obtain a patterned resin film with a width of 10 mm. Thereafter, the patterned resin film was heated in a nitrogen atmosphere from room temperature (25°C) to 230°C over 1 hour using an inert gas oven (INH-9CD-S), and then heat-treated for 2 hours while maintaining the temperature. A patterned cured film for mechanical strength measurement with a film thickness of about 10 μm was obtained.

The cured film was peeled off from the silicon substrate, and the elongation at break of the peeled cured film was measured using Autograph AGS-H100N manufactured by Shimadzu Corporation. The width of the sample was 10 mm, the film thickness was about 10 μm, and the distance between chucks was 20 mm. The pulling speed was 5 mm/min, and the environmental temperature was room temperature (25° C.). The average of the top three measured values of five test pieces obtained from cured films obtained under the same conditions was taken as the elongation at break and the strength at break.

The resin composition of the example containing the component (B2) was able to open a pattern of 1 μm in a cured pattern film thickness of 5 μm, and exhibited very high resolution.
Furthermore, a patterned cured film with high breaking strength could be formed. On the other hand, with the resin compositions of Comparative Examples 1 to 3 containing only the component (B1), a 2 μm pattern could be opened, but a 1 μm pattern could not be opened.

(Examples 12 to 14)
Photosensitive resin compositions were prepared in the same manner as in Examples 1 to 7, except that components (A) to (D) were used in the amounts shown in Table 3.

In the photosensitive resin compositions of Examples 12 to 14, the strength and elongation at break of the patterned cured film were further improved by further containing the component (D).

Claims (9)

(A) an alkali-soluble resin having a phenolic hydroxyl group;
(B) a compound having a sulfonic acid ester at the 4-position that generates an acid when exposed to light;
A photosensitive resin composition containing. The alkali-soluble resin having a phenolic hydroxyl group (A) consists of a compound represented by the following formula (21), a compound represented by the following formula (22), and a compound represented by the following formula (23). The photosensitive resin composition according to claim 1, having a structure derived from at least one selected from the group.

(In general formula (21), R ²¹ represents a hydrogen atom or a methyl group, and R ²² represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. , a represents an integer from 0 to 3, and b represents an integer from 1 to 3. The sum of a and b is 5 or less.)

(In general formula (22), R ²³ represents a hydrogen atom or a methyl group, and R ²⁴ represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. , c represents an integer of 0 to 3.The alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 10 carbon atoms, or alkoxy group having 1 to 10 carbon atoms represented by R ²⁴ are the same as R ²² , respectively. can be exemplified)

(In general formula (23), R ²⁵ represents a hydrogen atom or a methyl group, and R ²⁶ represents an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms.) The (B) compound having a sulfonic acid ester at the 4-position that generates an acid when exposed to light contains at least a condensate of a compound represented by the following formula (b0) and a compound represented by the following formula (b2). The photosensitive resin composition according to claim 1 or 2, which is an o-quinonediazide compound.

The photosensitive resin composition according to claim 1 or 2, further comprising (C) a compound that undergoes a crosslinking reaction when heated. The photosensitive resin composition according to claim 4, wherein the compound (C) that undergoes a crosslinking reaction due to heat is a compound having an alkoxy group or an epoxy group. (D) The photosensitive resin composition according to claim 1 or 2, further comprising an elastomer. A step of applying the photosensitive resin composition according to claim 1 or 2 to a part or the entire surface of the substrate and drying it to form a resin film;
a step of exposing a part or the entire surface of the resin film;
Developing the exposed resin film with an alkaline aqueous solution to form a patterned resin film;
A method for producing a patterned cured film, comprising the step of heating the patterned resin film. A patterned cured film having a pattern, the pattern containing a cured product of the photosensitive resin composition according to claim 1 or 2. A semiconductor device comprising the patterned cured film according to claim 8 as an interlayer insulating layer or a surface protection layer.