Radiation-sensitive composition, cured film, display element, and method for producing cured film

Abstract

To provide a radiation-sensitive composition that can form a cured film having superior radiation sensitivity, melt flow resistance, dielectric constant, and chemical resistance.SOLUTION: There is provided a radiation-sensitive composition comprising a polymer component (A), a quinonediazide compound (B), and a solvent (C), wherein the polymer component (A) includes in the same polymer or in separate polymers; at least one structural unit (I) selected from the group consisting of a structural unit having an acid group and a structural unit derived from maleimide; a structural unit (II) comprising an alicyclic epoxy group; and a structural unit (III) derived from a (meth)acrylate having an alicyclic structure (excluding the structural unit (II)), the structural unit (II) being present in an amount of 10 mass% or more based on all structural units constituting the polymer component (A) and the structural unit (III) being present in an amount of 10 mass% or more based on all structural units constituting the polymer component (A).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a radiation-sensitive composition, a cured film, a display element, and a method for producing a cured film.

Background Art

[0002] In display elements, insulating cured films such as interlayer insulating films for insulating between wirings and substrates or between wirings, planarization films, and partition walls are provided. Generally, the cured film is formed by subjecting a coating film formed from a radiation-sensitive composition to exposure and development treatments and then performing a heat treatment to thermally cure it.

[0003] As a material for forming such a cured film, a photosensitive resin composition containing an acrylic copolymer obtained by copolymerizing an unsaturated carboxylic acid, an epoxy group-containing unsaturated compound, and an olefinic unsaturated compound at a specific ratio, a quinonediazide compound, a solvent, and a specific silane-based surfactant is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, cured films (for example, planarization films, interlayer insulating films, etc.) used in display devices such as organic light-emitting diodes (OLEDs) and liquid crystal display devices (LCDs) are required to have even lower dielectric constants due to changes in panel and element structures. Also, exposure sensitivity has become more important in order to increase productivity.

[0006] As a method for reducing the dielectric constant of a cured film, a method of introducing a functional group with a small molar polarization or the like into the components of a composition for forming a cured film is known. However, depending on the type of functional group to be introduced, the hydrophilicity of the composition for forming a cured film decreases, and as a result, the developability and exposure sensitivity may decrease. That is, it has been difficult for conventional compositions for forming a cured film to achieve both cured film physical properties such as developability, radiation sensitivity, and chemical resistance, and a reduction in the dielectric constant.

[0007] The present invention has been made in view of the above problems, and a main object thereof is to provide a radiation-sensitive composition capable of forming a cured film excellent in radiation sensitivity, melt flow resistance, relative permittivity, and chemical resistance.

Means for Solving the Problems

[0008] According to the present invention, the following radiation-sensitive composition, cured film, display device, and method for manufacturing a cured film are provided.

[0009] In one embodiment of the present invention, a polymer component (A), a quinonediazide compound (B), a solvent (C), and a radiation-sensitive composition containing wherein the polymer component (A) has a structural unit (I) having an acid group, a structural unit (II) containing an alicyclic epoxy group, a structural unit (III) derived from a (meth)acrylate having an alicyclic structure (excluding the structural unit (II)), and is contained in the same polymer or different polymers, the structural unit (II) is 10% by mass or more based on all the structural units constituting the polymer component (A), and the structural unit (III) is 10% by mass or more based on all the structural units constituting the polymer component (A). The present invention relates to a radiation-sensitive composition.

[0010] In another embodiment of the present invention, a step of applying the radiation-sensitive composition onto a substrate, A step of removing a solvent from the applied radiation-sensitive composition; A step of irradiating the radiation-sensitive composition from which the solvent has been removed with radiation; A step of developing the radiation-sensitive composition irradiated with the radiation; A step of thermally curing the developed radiation-sensitive composition; It relates to a method for producing a cured film, including these steps.

[0011] In another embodiment, the present invention relates to a cured film formed using the radiation-sensitive composition and a display element including the cured film.

Effects of the Invention

[0012] The radiation-sensitive composition of the present invention contains a polymer component (A) containing a structural unit (II) containing an alicyclic epoxy group and a structural unit (III) derived from a (meth)acrylate having an alicyclic structure in a specific amount. By doing so, while maintaining high radiation sensitivity, the glass transition temperature of the polymer can be increased. As a result, melt flow can be suppressed, the pattern shape is good, the relative permittivity can be made sufficiently low, and a cured film excellent in chemical resistance can be formed.

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

[0014] Hereinafter, matters related to the embodiments will be described in detail. In this specification, a numerical range described using "~" means that the numerical values described before and after "~" are included as the lower limit value and the upper limit value. A "structural unit" is a unit mainly constituting the main chain structure and means a unit contained in at least two or more in the main chain structure.

[0015] As used herein, the term "hydrocarbon group" means a group including a linear hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The term "linear hydrocarbon group" means a linear or branched hydrocarbon group having no cyclic structure in the main chain and consisting only of a linear structure. However, the linear hydrocarbon group may be saturated or unsaturated. The term "alicyclic hydrocarbon group" means a hydrocarbon group having only an alicyclic hydrocarbon structure as the ring structure and not having an aromatic ring structure. However, the alicyclic hydrocarbon group does not necessarily consist only of the structure of the alicyclic hydrocarbon, and also includes those having a linear structure in a part thereof. The term "aromatic hydrocarbon group" means a hydrocarbon group having an aromatic ring structure as the ring structure. However, the aromatic hydrocarbon group does not necessarily consist only of the aromatic ring structure, and may include a linear structure or an alicyclic hydrocarbon structure in a part thereof. Note that the ring structures of the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent consisting of a hydrocarbon structure. The term "cyclic hydrocarbon" means a group including an alicyclic hydrocarbon and an aromatic hydrocarbon.

[0016] As used herein, "(meth)acrylo" means including "acrylo" and "methacrylo", and "(meth)acryl" means including "acryl" and "methacryl". "(meth)acrylate" means including "acrylate" and "methacrylate".

[0017] ≪Radiation-sensitive composition≫ The curable composition according to the present embodiment (hereinafter also referred to as "the present composition") is a polymer component (A), a quinonediazide compound (B), a solvent (C), and is a radiation-sensitive composition containing wherein the polymer component (A) contains a structural unit (I) having an acid group, a structural unit (II) containing an alicyclic epoxy group, a structural unit (III) derived from a (meth)acrylate having an alicyclic structure (excluding the structural unit (II)), and is contained in the same polymer or different polymers, The structural unit (II) is 10% by mass or more based on all the structural units constituting the polymer component (A), The present invention relates to a radiation-sensitive composition in which the structural unit (III) is 10% by mass or more based on all the structural units constituting the polymer component (A).

[0018] Hereinafter, each component contained in the present composition and other components blended as necessary will be described. Unless otherwise specified, each component may be used alone or in combination of two or more.

[0019] <Polymer component (A)> The polymer component (A) is an aggregate of polymers containing structural units (I) to (III). These structural units may be contained in the same polymer, or these structural units may be contained in different polymers. It is sufficient that the polymer component (A) contains the structural units (I) to (III) as a whole of the polymers constituting it. Therefore, the polymer component (A) may be composed of one kind of polymer as long as it contains the structural units (I) to (III), or may be composed of two or more kinds of polymers. The polymer component (A) may contain structural units other than the structural units (I) to (III). Further, the polymer component (A) may further contain a polymer having none of the structural units (I) to (III).

[0020] (Structural unit (I)) By the polymer component (A) containing a polymer containing the structural unit (I), good alkali solubility can be imparted to the polymer component. In the present specification, "alkali-soluble" means dissolving in an alkaline aqueous solution such as an aqueous solution of tetramethylammonium hydroxide having a concentration of 2.38% by mass.

[0021] The structural unit (I) is at least one structural unit selected from the group consisting of a structural unit (I-1) having an acid group and a structural unit (I-2) derived from maleimide.

[0022] The structural unit (I-1) is not particularly limited as long as it has an acid group. Examples of the acid group include a carboxy group, a sulfonic acid group, a phenolic hydroxyl group, etc. As the structural unit (I), specifically, it is preferably at least one selected from the group consisting of a structural unit having a carboxy group, a structural unit having a phenolic hydroxyl group, and a structural unit having a sulfonic acid group, and more preferably at least one selected from the group consisting of a structural unit having a carboxy group and a structural unit having a phenolic hydroxyl group. In the present specification, the "phenolic hydroxyl group" means a hydroxyl group directly bonded to an aromatic ring (for example, a benzene ring, a naphthalene ring, an anthracene ring, etc.).

[0023] The structural unit (I-1) is not particularly limited, but from the viewpoint of copolymerizability, it is preferably a structural unit derived from an unsaturated monomer having an acid group.

[0024] Specific examples of the monomer that gives the structural unit (I-1) include, as the monomer that gives the structural unit having a carboxy group, for example, unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, 4-vinylbenzoic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, etc.; as the monomer that gives the structural unit having a sulfonic acid group, for example, vinyl sulfonic acid, (meth)allyl sulfonic acid, styrene sulfonic acid, (meth)acryloyloxyethyl sulfonic acid, etc.; as the monomer that gives the structural unit having a phenolic hydroxyl group, for example, 4-hydroxystyrene, o-isopropenylphenol, m-isopropenylphenol, p-isopropenylphenol, hydroxyphenyl (meth)acrylate, etc., respectively.

[0025] The structural unit (I-2) is a structural unit derived from maleimide. The structural unit derived from maleimide means a structural unit derived from unsubstituted maleimide represented by the following formula.

[0026]

Chemical formula

[0027] As the structural unit (I), the structural unit (I-1) is preferable.

[0028] In the polymer component (A), from the viewpoint of imparting good solubility in an alkali developer, the content ratio of the structural unit (I) (when a plurality of types are included, the total content ratio) is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, and particularly preferably 10% by mass or more with respect to all the structural units constituting the polymer component (A). Further, from the viewpoint of sufficiently generating a difference in solubility in an alkali developer between the exposed portion and the unexposed portion and obtaining a pattern with a good shape, the content ratio of the structural unit (I) is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less with respect to all the structural units constituting the polymer component (A).

[0029] (Structural unit (II)) By including a polymer containing the structural unit (II) in the polymer component (A), a cured film having excellent melt flow resistance and chemical resistance can be formed.

[0030] The alicyclic epoxy group means a group having a structure in which an epoxy group is formed by two adjacent carbon atoms and an oxygen atom constituting an alicyclic group. Examples of the alicyclic epoxy group include a 2,3-epoxycyclobutyl group, a 2,3-epoxycyclopentyl group, a 3,4-epoxycyclohexyl group, a 3,4-epoxytricyclo[5.2.1.0 2,6 decane-yl group, a 5,6-epoxytricyclo[5.2.1.0 2,6 decane-yl group, a 2,3-epoxytricyclo[4.2.1.0 2,5 nonane-yl group and the like. Among these, a 3,4-epoxycyclohexyl group and a 3,4-epoxytricyclo[5.2.1.0 2,6 decane-yl group are preferable.

[0031] Examples of the monomer that provides the structural unit (II) include vinyl compounds having an alicyclic epoxy group and (meth)acrylates having an alicyclic epoxy group. Among these, (meth)acrylates having an alicyclic epoxy group are preferred.

[0032] As the structural unit (II), a structural unit represented by any of the following formulas (II-1) to (II-3) is preferred.

Chemical formula

[0033] R 1 Each independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and a hydrogen atom or a methyl group is preferred.

[0034] L 1 Each independently represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms.

[0035] Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms include a divalent chain hydrocarbon group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0036] Examples of the divalent chain hydrocarbon group having 1 to 20 carbon atoms include alkane diyl groups such as methane diyl group, ethane diyl group, propane diyl group, and butane diyl group, alkene diyl groups such as ethene diyl group, propene diyl group, and butene diyl group, and alkyne diyl groups such as ethyne diyl group, propyne diyl group, and butyne diyl group.

[0037] Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include divalent monocyclic alicyclic saturated hydrocarbon groups such as cyclopentanediyl group and cyclohexanediyl group, divalent monocyclic alicyclic unsaturated hydrocarbon groups such as cyclopentenediyl group and cyclohexenediyl group, divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornanediyl group, adamantanediyl group, and tricyclodecanediyl group, and divalent polycyclic alicyclic unsaturated hydrocarbon groups such as norbornenediyl group and tricyclodecenediyl group.

[0038] Examples of the divalent aromatic hydrocarbon group having 6 to 20 carbon atoms include arenediyl groups such as benzenediyl group, toluenediyl group, xylenediyl group, naphthalenediyl group, and anthracenediyl group, and arenediylalkanediyl groups such as benzenediylmethanediyl group, benzenediylethanediyl group, naphthalenediylmethanediyl group, and anthracenediylmethanediyl group.

[0039] n is an integer of 1 to 5, preferably an integer of 1 to 3, more preferably 1 or 2.

[0040] k1 is 0 or 1.

[0041] X 1 is a hydroxy group, a halogen atom, a cyano group, a nitro group, an alkyl group, or an alkoxy group.

[0042] As the alkyl group, an alkyl group having 1 to 10 carbon atoms represented by R 11 ~R 13 in the following formula (1) can be preferably adopted. As the alkoxy group, an alkoxy group having 1 to 6 carbon atoms represented by R 11 ~R 13 in the following formula (1) can be preferably adopted.

[0043] a1 is an integer of 0 to 3. When a1 is 2 or more, a plurality of X 1 are the same as or different from each other.

[0044] Specific examples of the structural unit (II) include, but are not limited to, those shown below. [Chemical Formula] (In the formula, R 1 has the same meaning as the above formulas (II-1) to (II-3).)

[0045] The content ratio of the above structural unit (II) (when including multiple types, the total content ratio) is 10% by mass or more, more preferably 12% by mass or more, and even more preferably 15% by mass or more, based on all the structural units constituting the polymer component (A). The above content ratio is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. By setting the content ratio of the structural unit (II) within the above range, a cured film having excellent melt flow resistance and chemical resistance can be formed.

[0046] (Structural unit (III)) By including a polymer containing the structural unit (III) in the polymer component (A), a cured film having excellent relative permittivity and chemical resistance can be formed.

[0047] The structural unit (III) is a structural unit derived from a (meth)acrylate having an alicyclic structure, excluding those corresponding to the structural unit (II).

[0048] Examples of the alicyclic structure include alicyclic structures having 3 to 20 ring members.

[0049] The alicyclic structure having 3 to 20 ring members is not particularly limited as long as it has an alicyclic structure, and may have a monocyclic, bicyclic, tricyclic, tetracyclic or higher polycyclic structure, and may be a bridged ring structure, a spiro ring structure, a ring assembly structure in which a plurality of rings are directly bonded by a single bond or a double bond, or any combination thereof. Among these, it is preferable to have a monocyclic, bicyclic or tricyclic bridged ring structure, such as cyclopentane, cyclohexane, norbornane, adamantane, tricyclo[5.2.1.0 2,6Decane is preferred, and among these, from the viewpoint of radiation sensitivity, monocyclic compounds such as cyclopentane and cyclohexane are more preferred.

[0050] As the structural unit (III), a structural unit represented by any of the following formulas (III-1) to (III-4) is preferred.

Chemical formula

[0051] R 2 Each independently represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and a hydrogen atom or a methyl group is preferred.

[0052] L 2 Each independently represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms. As the divalent hydrocarbon group having 1 to 20 carbon atoms, the same ones as the divalent hydrocarbon groups represented by L in the above formulas (II-1) to (II-3) 1 can be preferably employed.

[0053] p is an integer from 1 to 5, preferably an integer from 1 to 3, and more preferably 1 or 2.

[0054] k2 is 0 or 1.

[0055] X 2 is a hydroxy group, a halogen atom, a cyano group, a nitro group, an alkyl group, or an alkoxy group. As the alkyl group and the alkoxy group, the ones exemplified by X in the above formulas (II-1) to (II-3) 1 can be preferably employed.

[0056] a2 is an integer from 0 to 3. When a2 is 2 or more, a plurality of Xs 2 are the same as or different from each other.

[0057] Specific examples of the structural unit (III) include, but are not limited to, the following. [Chemical formula] (In the formula, R 2 has the same meaning as the above formulas (III-1) to (III-4).)

[0058] The content ratio of the above structural unit (III) (when including multiple types, the total content ratio) is 10% by mass or more, more preferably 12% by mass or more, and even more preferably 15% by mass or more with respect to all the structural units constituting the polymer component (A). The above content ratio is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. By setting the content ratio of the structural unit (III) within the above range, a cured film having excellent relative permittivity and radiation sensitivity can be formed.

[0059] (Structural unit IV) The polymer component (A) may further contain a structural unit (IV) having an alkoxysilyl group. Examples of the alkoxysilyl group include groups represented by the following formula (1). [Chemical formula] (In formula (1), R 11 , R 12 and R 13 are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. However, one or more of R 11 , R 12 and R 13 is an alkoxy group having 1 to 6 carbon atoms. "*" represents a bond.)

[0060] In the above formula (1), examples of the alkoxy group having 1 to 6 carbon atoms represented by R 11 ~R 13 include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, and a tert-butoxy group. Among these, R 11 ~R 13The alkoxy group represented by is preferably an alkoxy group having 1 to 3 carbon atoms, more preferably a methoxy group or an ethoxy group.

[0061] R 11 ~R 13 The alkyl group having 1 to 10 carbon atoms represented by may be linear or branched. R 11 ~R 13 Examples of the alkyl group having 1 to 10 carbon atoms represented by include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and the like. Among these, the alkyl group represented by R 11 ~R 13 is preferably a methyl group, an ethyl group or a propyl group.

[0062] R 11 ~R 13 One of the groups represented by is an alkoxy group having 1 to 6 carbon atoms. The remaining groups are preferably a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, an alkyl group having 1 to 10 carbon atoms or a phenyl group, more preferably a hydroxy group, an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 3 carbon atoms, and still more preferably an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 3 carbon atoms.

[0063] R 11 ~R 13 Preferably, two or more of these are alkoxy groups having 1 to 6 carbon atoms, and more preferably all are alkoxy groups having 1 to 6 carbon atoms.

[0064] The structural unit (IV) is preferably a structural unit derived from a monomer having a polymerizable carbon-carbon unsaturated bond (hereinafter also referred to as "unsaturated monomer"). Specifically, it is preferably at least one selected from the group consisting of the structural unit represented by the following formula (1-1) and the structural unit represented by the following formula (1-2).

Chemical formula

[0065] In the above formulas (1-1) and (1-2), the divalent aromatic ring group of R 7 、R 8 is preferably a substituted or unsubstituted phenylene group or a substituted or unsubstituted naphthylene group. The divalent chain hydrocarbon group is preferably an alkanediyl group having 1 to 6 carbon atoms, more preferably an alkanediyl group having 1 to 4 carbon atoms, and still more preferably a linear alkanediyl group having 1 to 4 carbon atoms.

[0066] Specific examples of the monomer that gives the structural unit (IV) include styryltrimethoxysilane, styryltriethoxysilane, styrylmethyldimethoxysilane, styrylethyldiethoxysilane, styryldimethoxyhydroxysilane, styryldiethoxyhydroxysilane, (meth)acryloxyphenyltrimethoxysilane, (meth)acryloxyphenyltriethoxysilane, (meth)acryloxyphenylmethyldimethoxysilane, (meth)acryloxyphenylethyldiethoxysilane, etc.; trimethoxy(4-vinylnaphthyl)silane, triethoxy(4-vinylnaphthyl)silane, methyldimethoxy(4-vinylnaphthyl)silane, ethyldiethoxy(4-vinylnaphthyl)silane, (meth)acryloxynaphthyltrimethoxysilane, etc.; 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 4-(meth)acryloxybutyltrimethoxysilane, etc. Among these, styryltrimethoxysilane, styryltriethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 4-(meth)acryloxybutyltrimethoxysilane are preferred, and 3-(meth)acryloxypropyltrimethoxysilane and 3-(meth)acryloxypropyltriethoxysilane are more preferred.

[0067] When the polymer component (A) contains the above structural unit (IV), the content ratio of the above structural unit (IV) (when including multiple types, the total content ratio) is preferably 0.5% by mass or more, more preferably 1% by mass or more, and further preferably 3% by mass or more with respect to all the structural units constituting the polymer component (A). The above content ratio is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less. Setting the content ratio of the structural unit (IV) within the above range is preferable because a cured film excellent in radiation sensitivity and chemical resistance can be obtained.

[0068] The polymer component (A) may further contain structural units other than the above structural units (I) to (IV). Examples of other structural units include a structural unit (V) derived from an aromatic vinyl compound, a structural unit (VI) derived from an N-substituted maleimide compound, a structural unit (VII) having a hydroxyl group, a structural unit (VIII) derived from an alkyl methacrylate compound, and a structural unit (IX) having an epoxy group (excluding those corresponding to the structural unit (II)). By the polymer component (A) containing at least one of the structural unit (V) and the structural unit (VI), it is suitable in that the glass transition temperature (Tg) of the polymer component (A) can be further increased and the effect of improving the pattern shape can be enhanced.

[0069] (Structural unit (V)) The aromatic vinyl compound constituting the structural unit (V) is not particularly limited. For example, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 5-t-butyl-2-methylstyrene, divinylbenzene, trivinylbenzene, t-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-dimethylaminoethylstyrene, N,N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-t-butylstyrene, 3-t-butylstyrene, 4-t-butylstyrene, diphenylethylene and other styrene compounds; vinylnaphthalene, divinylnaphthalene and other vinylnaphthalene compounds; heterocyclic vinyl compounds such as vinylpyridine and the like. Among these, the above aromatic vinyl compound is preferably a styrene compound.

[0070] When the polymer component (A) contains the structural unit (V), the content ratio of the structural unit (V) (in the case of containing a plurality of types, the total content ratio) is preferably 0.5% by mass or more, more preferably 1% by mass or more, based on all the structural units constituting the polymer component (A). The above content ratio is preferably 30% by mass or less, more preferably 25% by mass or less. By setting the content ratio of the structural unit (V) within the above range, a cured film with a better pattern shape can be obtained, the glass transition temperature of the polymer component (A) does not become too high, and the decrease in developability can be suppressed, which is preferable.

[0071] (Structural unit (VI)) Examples of the N-substituted maleimide compound constituting the structural unit (VI) include compounds in which the hydrogen atom bonded to the nitrogen atom of maleimide is substituted with a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, and a monovalent aromatic hydrocarbon group. Among these, the N-substituted maleimide compound constituting the structural unit (VI) preferably has a monovalent cyclic hydrocarbon group, and more preferably has a monovalent alicyclic hydrocarbon group having a monocyclic, bridged ring or spiro ring, in terms of being able to more highly improve the heat resistance.

[0072] Specifically, the structural unit (VI) is preferably a structural unit represented by the following formula (2). [Chemical formula] (In formula (2), R 5 is a monovalent cyclic hydrocarbon group. R 6 and R 7 are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)

[0073] In the above formula (2), R 5The ring structure of the cyclic hydrocarbon group may be directly bonded to the nitrogen atom, or may be bonded via a divalent linking group. Examples of the divalent linking group include alkane diyl groups such as a methylene group, an ethylene group, and a 1,3-propanediyl group. Among these, R 5 It is preferable that the ring structure of the cyclic hydrocarbon group is directly bonded to the nitrogen atom, and an alicyclic hydrocarbon group in which the structure of the alicyclic hydrocarbon is directly bonded to the nitrogen atom is more preferable. R 6 and R 7 are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0074] Specific examples of the N-substituted maleimide compound include, as compounds having an alicyclic hydrocarbon group, for example, N-cyclohexyl maleimide, N-cyclopentyl maleimide, N-(2-methylcyclohexyl) maleimide, N-(4-methylcyclohexyl) maleimide, N-(4-ethylcyclohexyl) maleimide, N-(2,6-dimethylcyclohexyl) maleimide, N-norbornyl maleimide, N-tricyclodecyl maleimide, N-adamantyl maleimide, etc.; as compounds having an aromatic hydrocarbon group, for example, N-phenyl maleimide, N-(2-methylphenyl) maleimide, N-(4-methylphenyl) maleimide, N-(4-ethylphenyl) maleimide, N-(2,6-dimethylphenyl) maleimide, N-benzyl maleimide, N-naphthyl maleimide, etc. Each can be mentioned. Among these N-substituted maleimide compounds, at least one selected from the group consisting of N-cyclohexyl maleimide, N-(4-methylcyclohexyl) maleimide, N-phenyl maleimide, and N-(4-methylphenyl) maleimide is preferable, and N-cyclohexyl maleimide is more preferable.

[0075] When the polymer component (A) contains the above structural unit (VI), the content ratio of the above structural unit (VI) (when a plurality of types are included, the total content ratio) is preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more, based on all the structural units constituting the polymer component (A), from the viewpoint of improving the melt flow resistance. From the viewpoint of radiation sensitivity, the above content ratio is preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less.

[0076] (Structural unit (VII)) The structural unit (VII) is preferably a structural unit derived from an unsaturated monomer having a hydroxyl group (alcoholic hydroxyl group). Specifically, examples thereof include structural units derived from monomers having one or more hydroxyl groups bonded to a saturated chain hydrocarbon group. By the polymer component (A) containing the structural unit (VII), it is possible to suppress a decrease in pattern forming ability due to variations in the pre-baking temperature during film formation, and it is preferable from the viewpoint of forming a good pattern and radiation sensitivity. The structural unit (VII) is not particularly limited, and examples thereof include (meth)acrylic compounds and maleimide compounds.

[0077] Specific examples of the structural unit (VII) include, as (meth)acrylic compounds, for example, hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, glycerol mono(meth)acrylate, etc.; as maleimide compounds, for example, N-(hydroxymethyl)maleimide, N-(2-hydroxyethyl)maleimide, N-(3-hydroxypropyl)maleimide, etc.

[0078] When the polymer component (A) contains the above structural unit (VII), the content ratio of the above structural unit (VII) (the total content ratio in the case of containing a plurality of types) is 1% by mass or more, preferably 5% by mass or more, and more preferably 10% by mass or more, based on all the structural units constituting the polymer component (A), from the viewpoint of suppressing the decrease in pattern forming ability due to the variation in pre-baking temperature. From the viewpoint of suppressing the decrease in developability, the above content ratio is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less.

[0079] (Structural unit (VIII)) The structural unit (VIII) can be contained in the polymer component (A) for the purpose of adjusting the glass transition temperature of the polymer. The monomer constituting the structural unit (VIII) is preferably a methacrylate compound in which the alkyl group bonded to the ester group has 1 to 10 carbon atoms. Examples thereof include acrylic acid alkyl ester compounds such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl acrylate, tert-butyl acrylate, and 2-ethylhexyl acrylate.

[0080] When the polymer component (A) contains the above structural unit (VIII), the content ratio of the above structural unit (VIII) (the total content ratio in the case of containing a plurality of types) is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more, based on all the structural units constituting the polymer component (A). The above content ratio is preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 60% by mass or less.

[0081] (Structural unit (IX)) The structural unit (IX) is a structural unit derived from an unsaturated monomer having an epoxy group, excluding those corresponding to the structural unit (II). Specific examples of the structural unit (IX) include at least one selected from the group consisting of the structural unit represented by the following formula (5-1) and the structural unit represented by the following formula (5-2).

[0082] [Chemical] (In formulas (5-1) and (5-2), R 20 is a group having an oxiranyl group or an oxetanyl group (excluding an alicyclic epoxy group). R A1 is a hydrogen atom, a methyl group, a hydroxymethyl group, a cyano group, or a trifluoromethyl group. L 3 is a single bond or a divalent linking group.)

[0083] In the above formulas (5-1) and (5-2), examples of R 20 include an oxiranyl group, an oxetanyl group, a 3-ethyloxetanyl group, and the like.

[0084] Examples of the divalent linking group of L 3 include an alkanediyl group such as a methylene group, an ethylene group, and a 1,3-propanediyl group; and a divalent group in which any methylene group of the alkanediyl group is replaced by -O-.

[0085] Specific examples of the monomer having an epoxy group include glycidyl (meth)acrylate, (3-methyloxetan-3-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)(meth)acrylate, (oxetan-3-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, and the like.

[0086] When the polymer component (A) contains the above structural unit (IX), the content ratio of the above structural unit (IX) (when including a plurality of types, the total content ratio) is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more with respect to all the structural units constituting the polymer component (A). The above content ratio is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less.

[0087] (Other structural units) Examples of other structural units include, in addition to the above, unsaturated dicarboxylic acid dialkyl ester compounds such as diethyl itaconate; unsaturated dicarboxylic acid anhydrides such as phthalic anhydride; conjugated diene compounds such as 1,3-butadiene and isoprene; nitrogen-containing vinyl compounds such as (meth)acrylonitrile, (meth)acrylamide, N-vinyl alkylamide, and N-vinyl pyrrolidone; and structural units derived from monomers such as vinyl chloride, vinylidene chloride, and vinyl acetate. In the polymer component (A), the content ratio of other structural units is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass or less based on all the structural units constituting the polymer component (A).

[0088] The content ratio of each structural unit is usually equivalent to the ratio of the monomers used in the production of the polymer component (A).

[0089] In the polymer component (A), the weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) is preferably 2,000 or more. When Mw is 2,000 or more, it is preferable in that a cured film having sufficiently high chemical resistance and good developability can be obtained. Mw is more preferably 5,000 or more, still more preferably 6,000 or more, and particularly preferably 8,000 or more. Also, from the viewpoint of improving film-forming properties, Mw is preferably 50,000 or less, more preferably 30,000 or less, still more preferably 20,000 or less, even more preferably 18,000 or less, and particularly preferably 15,000 or less.

[0090] In the polymer component (A), the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is preferably 4.0 or less, more preferably 3.0 or less, and still more preferably 2.7 or less. When the polymer component (A) is composed of two or more polymers, it is preferable that each polymer satisfies Mw and Mw / Mn in the above ranges respectively.

[0091] The content ratio of the polymer component (A) is preferably 10% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more with respect to the total amount of the solid content contained in the radiation-sensitive composition. Further, the content ratio of the polymer component (A) is preferably 95% by mass or less, and more preferably 90% by mass or less with respect to the total amount of the solid content contained in the radiation-sensitive composition. By setting the content ratio of the polymer component (A) within the above range, it is suitable in that a cured film having sufficiently high chemical resistance and exhibiting good developability and transparency can be obtained.

[0092] The polymer component (A) can be produced, for example, by using an unsaturated monomer into which each of the above-described structural units can be introduced and according to a known method such as radical polymerization in the presence of a polymerization initiator and the like in an appropriate solvent. Specifically, examples of the polymerization initiator used include azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and dimethyl 2,2'-azobis(isobutyrate). The usage ratio of the polymerization initiator is preferably 0.01 to 30 parts by mass with respect to 100 parts by mass of the total amount of the monomers used in the reaction. Examples of the polymerization solvent include alcohols, ethers, ketones, esters, hydrocarbons, and the like.

[0093] In the above polymerization reaction, the reaction temperature is usually 30°C to 180°C. The reaction time varies depending on the types of the initiator and the monomer and the reaction temperature, but is usually 0.5 to 10 hours. The amount of the organic solvent used is preferably such that the total amount of the monomers used in the reaction is 0.1 to 60% by mass with respect to the total amount of the reaction solution. The polymer obtained by the polymerization reaction can be isolated using a known isolation method such as a method of pouring the reaction solution into a large amount of a poor solvent and drying the precipitate obtained thereby under reduced pressure, or a method of distilling off the reaction solution under reduced pressure using an evaporator.

[0094] <Quinonediazide compound (B)> The quinonediazide compound (B) is a radiation-sensitive acid generator that generates carboxylic acid upon irradiation with radiation. As the quinonediazide compound, it is preferable to use a condensate of a phenolic compound or an alcoholic compound (hereinafter also referred to as "parent nucleus") and 1,2-naphthoquinonediazide sulfonic acid halide.

[0095] Examples of the above-mentioned parent nucleus include trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone, hexahydroxybenzophenone, (polyhydroxyphenyl)alkane, and other parent nuclei.As these specific examples, as trihydroxybenzophenones, for example, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, etc.; as tetrahydroxybenzophenones, for example, 2,2’,4,4’-tetrahydroxybenzophenone, 2,3,4,3’-tetrahydroxybenzophenone, 2,3,4,4’-tetrahydroxybenzophenone, 2,3,4,2’-tetrahydroxy-4’-methylbenzophenone, 2,3,4,4’-tetrahydroxy-3’-methoxybenzophenone, etc.; as pentahydroxybenzophenones, for example, 2,3,4,2’,6’-pentahydroxybenzophenone, etc.; as hexahydroxybenzophenones, for example, 2,4,6,3’,4’,5’-hexahydroxybenzophenone, 3,4,5,3’,4’,5’-hexahydroxybenzophenone, etc.; as (polyhydroxyphenyl)alkanes, for example, bis(2,4-dihydroxyphenyl)methane, bis(p-hydroxyphenyl)methane, tri(p-hydroxyphenyl)methane, 1,1,1-tri(p-hydroxyphenyl)ethane, bis(2,3,4-trihydroxyphenyl)methane, 2,2-bis(2,3,4-trihydroxyphenyl)propane, 1,1,3-tris(2,5-dimethyl-4-hydroxyphenyl)-3-phenylpropane, 4,4’-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol, bis(2,5-dimethyl-4-hydroxyphenyl)-2-hydroxyphenylmethane, 3,3,3’,3’-tetramethyl-1,1’-spirobiindene-5,6,7,5’,6’,7’-hexanol, 2,2,4-trimethyl-7,2’,4’-trihydroxyflavan, etc.; as other parent nuclei, for example, 2-methyl-2-(2,4-dihydroxyphenyl)-4-(4-hydroxyphenyl)-7-hydroxycoumaran, 2-[bis{(5-isopropyl-4-hydroxy-2-methyl)phenyl}methyl], etc. can be respectively cited.

[0096] Among these, as the mother nucleus, 2,3,4,4'-tetrahydroxybenzophenone, 1,1,1-tri(p-hydroxyphenyl)methane, 1,1,1-tri(p-hydroxyphenyl)ethane, and 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol are preferable.

[0097] As the 1,2-naphthoquinonediazide sulfonic acid halide, 1,2-naphthoquinonediazide sulfonic acid chloride is preferable. Specifically, 1,2-naphthoquinonediazide-4-sulfonic acid chloride, 1,2-naphthoquinonediazide-5-sulfonic acid chloride, etc. may be mentioned. Among these, as the 1,2-naphthoquinonediazide sulfonic acid halide, 1,2-naphthoquinonediazide-5-sulfonic acid chloride can be preferably used.

[0098] In the condensation reaction for obtaining the above condensate, the ratio of the mother nucleus to the 1,2-naphthoquinonediazide sulfonic acid halide is such that the amount of the 1,2-naphthoquinonediazide sulfonic acid halide used corresponds to preferably 30 to 85 mol%, more preferably 50 to 70 mol% based on the number of OH groups in the mother nucleus. The above condensation reaction can be carried out according to a known method. A 1,2-quinonediazide compound is obtained by the condensation reaction of the mother nucleus and the 1,2-naphthoquinonediazide sulfonic acid halide.

[0099] The content ratio of the quinonediazide compound (B) in the radiation-sensitive composition is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more with respect to 100 parts by mass of the polymer component (A). Further, the content ratio of the quinonediazide compound (B) is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, and still more preferably 30 parts by mass or less with respect to 100 parts by mass of the polymer component (A). When the content ratio of the quinonediazide compound (B) is 2 parts by mass or more, acid is sufficiently generated by irradiation with radiation, and the difference in solubility between the irradiated portion and the non-irradiated portion with respect to the alkaline solution can be made sufficiently large, which is preferable. Thereby, good patterning can be performed. Further, it is preferable because the amount of acid involved in the reaction with the polymer component (A) can be increased and sufficient chemical resistance can be ensured. On the other hand, when the content ratio of the quinonediazide compound (B) is 100 parts by mass or less, the unreacted quinonediazide compound (B) can be made sufficiently small, which is preferable from the viewpoint of suppressing the decrease in developability due to the remaining of the quinonediazide compound (B).

[0100] <Solvent (C)> The radiation-sensitive composition of the present disclosure is a liquid composition in which the polymer component (A), the quinonediazide compound (B), and other components optionally blended are preferably dissolved or dispersed in the solvent (C). As the solvent to be used, an organic solvent that dissolves each component blended in the radiation-sensitive composition and does not react with each component is preferable.

[0101] The solvent (C) is not particularly limited, and examples thereof include alcohol solvents, ether solvents, ester solvents, ketone solvents, amide solvents, and the like. The solvent (C) may be used alone or in combination of two or more.

[0102] Examples of alcohol solvents include alkyl alcohols such as methanol, ethanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, t-butyl alcohol, 1-hexanol, 1-octanol, 1-nonanol, 1-dodecanol, 1-methoxy-2-propanol, and diacetone alcohol; and aromatic alcohols such as benzyl alcohol.

[0103] Examples of ether solvents include ethylene glycol monoalkyl ethers such as diethylene glycol methyl ethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether; diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether; diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether and diethylene glycol ethyl methyl ether; and dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, and dipropylene glycol monobutyl ether.

[0104] Examples of ester solvents include carboxylic acid esters such as ethyl acetate, i-propyl acetate, n-butyl acetate, amyl acetate, ethyl lactate, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate; polyhydric alcohol carboxylate solvents such as propylene glycol diacetate; and polyhydric alcohol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate.

[0105] Examples of the ketone solvents include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, and the like.

[0106] Among these, ether solvents and ester solvents are preferred, ester solvents are more preferred, and polyhydric alcohol partial ether carboxylate solvents are even more preferred. Also, among the ether solvents and ester solvents, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and methyl 3-methoxypropionate are preferred.

[0107] The content of the solvent (C) in the present composition is not particularly limited, but it is preferably prepared such that the solid content (components other than the solvent (C)) concentration of the present composition is within the following range. As the lower limit value of the solid content concentration in the present composition, 5% by mass is preferred, 8% by mass is more preferred, and 15% by mass is even more preferred. On the other hand, as the upper limit value of the solid content concentration, 60% by mass is preferred, 40% by mass is more preferred, and 30% by mass is even more preferred. When the solid content concentration of the radiation-sensitive composition is 5% by mass or more, it is preferable in that a sufficient film thickness of the coating film can be ensured when the radiation-sensitive composition is applied onto a substrate. Also, when the solid content concentration is 60% by mass or less, it is preferable in that the film thickness of the coating film does not become excessively large, and furthermore, the viscosity of the radiation-sensitive composition can be moderately increased to ensure good coatability.

[0108] <Solvent (C1)> In addition to the above solvent (C), the composition of the present disclosure can contain a solvent (C1) having a boiling point of 180°C or higher and a hydrogen bonding term δH of the Hansen solubility parameter of 3.0 or more and 13.0 or less. Here, the Hansen solubility parameter (HSP value) is an index obtained by dividing the Hildebrand solubility parameter (SP value) into three components: a dispersion force term δD, a polar term δP, and a hydrogen bonding term δH, taking into account the polarity of physical properties, and "SP" 2= δD 2 + δP 2 + δH 2 There is a relationship of ". In this specification, the Hansen solubility parameter is a value calculated using the calculation software HSPiP ver.5. The boiling point of the solvent is the value under 1 atm.

[0109] The solvent (C1) only needs to have a boiling point of 180 °C or higher and a hydrogen bonding term δH of the HSP value of 3.0 or higher and 13.0 or lower, and its type is not particularly limited. Among them, the solvent (C1) is preferably at least one selected from the group consisting of alcohols, carbonates, ethers, and esters. The solvent (C1) may be a compound having a chain structure or a compound having a cyclic structure.

[0110] Specific examples of the solvent (C1) include dihydroterpineol (δH = 6.69, boiling point = 210 °C), (S)-4-methyl-1,3-dioxolan-2-one (δH = 7.35, boiling point = 242 °C), diethylene glycol monobutyl ether (δH = 10.46, boiling point = 231 °C), dipropylene glycol methyl ether acetate (δH = 5.78, boiling point = 213 °C), triethylene glycol monobutyl ether (δH = 9.14, boiling point = 278 °C), propyl lactate (δH = 11.7, boiling point = 188 °C), benzyl alcohol (δH = 12.5, boiling point 205 °C), etc.

[0111] When the solvent (C) contains the solvent (C1), the content of the solvent (C1) is preferably 10% by mass or less based on the total amount of the solvent.

[0112] <Other components> In addition to the polymer component (A), quinonediazide compound (B), and solvent (C) described above, the radiation-sensitive composition of the present disclosure may further contain components other than these (hereinafter also referred to as "other components"). Examples of other components include, for example, a polymerization initiator (photo radical polymerization initiator, photo cationic polymerization initiator, etc.), a polyfunctional polymerizable compound (polyfunctional (meth)acrylate, etc.), an adhesion aid (functional silane coupling agent, etc.), a surfactant (fluorine-based surfactant, silicone-based surfactant (silane-based surfactant), nonionic surfactant, etc.), a polymerization inhibitor, an antioxidant, a chain transfer agent, and the like. The blending ratio of these components is appropriately selected according to each component within a range that does not impair the effects of the present disclosure. Further, the radiation-sensitive composition of the present disclosure may contain a silane-based surfactant, but it is preferably not contained.

[0113] The solid content concentration of the radiation-sensitive composition of the present disclosure (the ratio of the total mass of the components other than the solvent (C) in the radiation-sensitive composition to the total mass of the radiation-sensitive composition) is appropriately selected in consideration of viscosity, volatility, and the like.

[0114] (Dielectric constant of the cured film obtained by the radiation-sensitive composition) By curing this composition, a cured film having a sufficiently low dielectric constant can be obtained. Specifically, the dielectric constant of the obtained cured film at a frequency of 10 kHz is preferably 3.4 or less, more preferably less than 3.1. Details of the method for measuring the dielectric constant of the cured film will follow the method described in the examples below.

[0115] By using a quinonediazide compound (B) as a radiation-sensitive acid generator together with a polymer component (A) containing structural units (I) to (III), the radiation-sensitive composition of the present disclosure can increase the glass transition temperature of the polymer while maintaining high radiation sensitivity. As a result, the melt flow can be suppressed, the pattern shape is good, the relative dielectric constant can be made sufficiently low, and a cured film excellent in chemical resistance can be formed. Such a radiation-sensitive composition of the present disclosure is useful as a composition for forming a planarization film or an interlayer insulating film of a display element.

[0116] ≪Method for Manufacturing Hard Film≫ The hard film of the present disclosure is formed from the radiation-sensitive composition prepared as described above. The radiation-sensitive composition of the present disclosure has high radiation sensitivity, can suppress melt flow due to heat after patterning, and also has good relative permittivity and chemical resistance.

[0117] In the production of the hard film, by using the above radiation-sensitive composition, a positive-type hard film can be formed by irradiation with radiation (such as ultraviolet rays, far ultraviolet rays, visible light, etc.). The hard film of the present disclosure can be produced, for example, by a method including the following (Step 1) to (Step 5). (Step 1) A step of applying the radiation-sensitive composition on a substrate to form a coating film. (Step 2) A step of removing the solvent from the coating film. (Step 3) A step of irradiating the coating film from which the solvent has been removed with radiation. (Step 4) A step of developing the coating film irradiated with radiation. (Step 5) A step of thermally curing the developed coating film. Hereinafter, each step will be described in detail.

[0118] <Steps 1 and 2: Coating Film Formation Step> In this step, the above radiation-sensitive composition is applied to the surface on which the coating film is to be formed (hereinafter also referred to as the "film-forming surface"), and preferably, heat treatment (pre-baking) is performed to remove the solvent and form a coating film on the film-forming surface. The material of the film-forming surface is not particularly limited. For example, when forming a planarization film using a radiation-sensitive composition, the above radiation-sensitive composition is applied on a substrate provided with a switching element such as a TFT to form a coating film. As the substrate, for example, a glass substrate or a resin substrate is used.

[0119] As a method for applying a radiation-sensitive composition, for example, a spray method, a roll coating method, a spin coating method, a slit die coating method, a bar coating method, and an inkjet method can be mentioned. Among these, it is preferably carried out by a spin coating method, a slit die coating method, or a bar coating method. The pre-baking conditions vary depending on the types and content ratios of the respective components in the radiation-sensitive composition, but for example, they are 60 to 130 °C for 0.5 to 10 minutes. The film thickness of the formed coating film (that is, the film thickness after pre-baking) is preferably 1 to 12 μm.

[0120] <Process 3: Exposure Process> In this process, at least a part of the coating film formed in the above Processes 1 and 2 is irradiated with radiation. At this time, by irradiating the coating film with radiation through a mask having a predetermined pattern, a cured film having a pattern (for example, an interlayer insulating film) can be formed. Examples of the radiation include charged particle beams such as ultraviolet rays, far ultraviolet rays, visible light, X-rays, and electron beams. Among these, ultraviolet rays are preferable, and for example, g-line (wavelength 436 nm), i-line (wavelength 365 nm) can be mentioned. The exposure dose of the radiation is preferably 0.1 to 20,000 J / m 2 is preferable.

[0121] <Process 4: Development Process> In this process, the coating film irradiated with radiation in the above Process 3 is developed. Specifically, positive development is performed in which the coating film irradiated with radiation in Process 3 is developed with a developer to remove the irradiated portion of the radiation. Examples of the developer include an aqueous solution of an alkali (basic compound). Examples of the alkali include sodium hydroxide, tetramethylammonium hydroxide, and the alkalis exemplified in paragraph

[0127] of JP-A-2016-145913. From the viewpoint of obtaining appropriate developability, the alkali concentration in the aqueous alkali solution is preferably 0.1 to 5.0% by mass. Examples of the development method include appropriate methods such as a puddle method, a dipping method, a rocking immersion method, and a shower method. The development time varies depending on the composition of the composition, but for example, it is 30 to 120 seconds. In addition, after the development process, it is preferable to perform a rinsing process by running water washing on the patterned coating film.

[0122] <Process 5: Heating Process> In this process, a treatment (post-baking) for heating the coating film developed in the above Process 4 is performed. As a result, the curing reaction of the film proceeds, and a cured film showing good chemical resistance is obtained. The post-baking can be carried out using a heating device such as an oven or a hot plate. Regarding the post-baking conditions, the heating temperature is, for example, 120 to 250°C. Also, the heating time is, for example, 5 to 40 minutes when performing the heat treatment on a hot plate, and 10 to 80 minutes when performing the heat treatment in an oven. In this way, a cured film having a target pattern can be formed on the substrate.

[0123] Note that a post-exposure process may be further included between Process 4 and Process 5. By irradiating the developed coating film with radiation, a cured film excellent in melt flow resistance and transparency in the heating process can be formed. Examples of the radiation include charged particle beams such as ultraviolet rays, far ultraviolet rays, visible light, X-rays, and electron beams. Among these, ultraviolet rays are preferable, and for example, g-line (wavelength 436 nm), i-line (wavelength 365 nm) can be mentioned. The exposure amount of the radiation is preferably 0.1 to 20,000 J / m 2 is preferable.

[0124] ≪Cured Film≫ The cured film of the present disclosure is formed using the above-described radiation-sensitive composition. The radiation-sensitive composition of the present disclosure has high radiation sensitivity, can suppress melt flow due to heat after patterning, and also has good relative permittivity and chemical resistance. Therefore, the above cured film is useful as an insulating film for organic EL elements. Specifically, the above cured film can be used as a planarization film for flattening surface irregularities caused by thin film transistors (TFTs) or the like, an interlayer insulating film for insulating between wirings, a partition wall and a bank for defining a region where a light-emitting layer is formed, a protective film for protecting TFTs or the like, a spacer, an adhesive layer for color filters, etc. in an organic EL element. In this specification, the "partition wall" refers to a member used for color separation such as a color filter or a color conversion layer using quantum dots, and the "bank" refers to a member for partitioning a light-emitting layer. Among these, the cured film of the present disclosure is particularly useful as an interlayer insulating film or a planarization film.

[0125] ≪Display element≫ The display element of the present disclosure includes a cured film formed using the above-described radiation-sensitive composition. Examples of the display element include a liquid crystal display element, an organic electroluminescence (EL) display element, a micro LED display element, etc.

[0126] The display element of the present disclosure can be effectively applied to various uses, and can be used, for example, as various display devices such as watches, portable game machines, word processors, notebook personal computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, and information displays.

Examples

[0127] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" are based on mass unless otherwise specified.

[0128] [Weight average molecular weight (Mw) and number average molecular weight (Mn)] The Mw and Mn of the polymer were measured by the following method. · Measurement method: Gel Permeation Chromatography (GPC) method · Apparatus: GPC-101 manufactured by Showa Denko K.K. · GPC column: Combine GPC-KF-801, GPC-KF-802, GPC-KF-803 and GPC-KF-804 manufactured by Shimadzu GL Sciences Inc. · Mobile phase: Tetrahydrofuran · Column temperature: 40 °C · Flow rate: 1.0 mL / min · Sample concentration: 1.0 mass% · Sample injection volume: 100 μL · Detector: Differential refractometer · Standard substance: Monodisperse polystyrene

[0129] [Monomer] The monomers used in the synthesis of the copolymer are as follows. (Structural unit (I)) MA: Methacrylic acid PIPE: p-Isopropenylphenol MI: Maleimide (Structural unit (II)) ECHMA: 3,4-Epoxycyclohexylmethyl methacrylate ETCDA: 3,4-Epoxytricyclo[5.2.1.0 2,6 decane-9-yl acrylate and 3,4-epoxytricyclo[5.2.1.0 2,6 decane-8-yl acrylate mixture [50:50 (molar ratio)] (Structural unit (III)) CHMA: Cyclohexyl methacrylate CHA: Cyclohexyl acrylate DCM: Dicyclopentanyl methacrylate DCA: Dicyclopentanyl acrylate IBA: Isobornyl acrylate (Structural unit (IV)) MPTMS: 3-Methacryloxypropyltrimethoxysilane MPTES: 3-Methacryloxypropyltriethoxysilane (Structural units other than structural units (I) to (IV)) CHMI: N-cyclohexylmaleimide GMA: Glycidyl methacrylate MMA: Methyl methacrylate HEMA: 2-Hydroxyethyl methacrylate

[0130] Hereinafter, unless otherwise specified, the number of parts represents the number of parts by weight.

[0131] <Synthesis of polymer (A)> [Synthesis Example 1] Synthesis of polymer (A-1) Into a flask equipped with a condenser and a stirrer, 13 parts of dimethyl 2,2'-azobis(isobutyrate) and 200 parts of diethylene glycol methyl ethyl ether were charged. Subsequently, 13 parts of methacrylic acid, 15 parts of 3,4-epoxycyclohexylmethyl methacrylate, 15 parts of cyclohexyl methacrylate, and 57 parts of methyl methacrylate were charged. After nitrogen substitution, while gently stirring, the temperature of the solution was raised to 80°C and maintained at this temperature for 5 hours to obtain a polymer solution containing polymer (A-1). The solid content concentration of this polymer solution was 35.3% by mass, the Mw of polymer (A-1) was 11,000, and the molecular weight distribution (Mw / Mn) was 2.4.

[0132] [Synthesis Examples 2 to 16, Comparative Synthesis Examples 1 to 6] Synthesis of polymers (A-2) to (A-16), polymers (A'-1 to A'-6) Polymer solutions containing polymers (A-2) to (A-16), polymers (A'-1) to (A'-3), (A'-5) to (A'-6) having a solid content concentration, molecular weight, and molecular weight distribution equivalent to those of polymer (A-1) were obtained in the same manner as in Synthesis Example 1, except that the components of the types and blending amounts (parts by mass) shown in Table 1 were used. Polymer (A'-4) was synthesized according to Synthesis Example 1 in paragraph

[0133] of JP-A-2007-156471. In Tables 1 and 2 below, "-" indicates that the corresponding component was not used.

[0133]

Table 1

[0134] <Preparation of Radiation-Sensitive Composition> The polymer (A), 1,2-quinonediazide compound (B), and solvent (C) used in the preparation of the radiation-sensitive composition are shown below.

[0135] 《Polymer (A)》 A-1 to A-16: Polymers (A-1) to (A-16) synthesized in Synthesis Examples 1 to 16 A'-1 to A'-6: Polymers (A'-1) to (A'-6) synthesized in Comparative Synthesis Examples 1 to 6 《Quinonediazide (B)》 B-1: Condensate of 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl]ethylidene]bisphenol (1.0 mol) and 1,2-naphthoquinonediazide-5-sulfonic acid chloride (2.0 mol) 《Solvent (C)》 C-1: Diethylene glycol methyl ethyl ether (EDM) C-2: Propylene glycol monomethyl ether (PGME) C-3: Propylene glycol monomethyl ether acetate (PGMEA)

[0136] <Preparation of Radiation-Sensitive Composition> [Example 1] To a polymer solution containing polymer (A-1), 20 parts of quinonediazide compound (B-1) was mixed with respect to the amount corresponding to 100 parts (solid content) of polymer (A-1). Diethylene glycol methyl ethyl ether (EDM), propylene glycol monomethyl ether (PGME), and propylene glycol monomethyl ether acetate (PGMEA) were added so that the final solid content concentration became 20% by mass. The ratio of the solvents in the radiation-sensitive composition was added so that EDM:PGME:PGMEA = 50:25:25. Then, it was filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive composition.

[0137] [Examples 2 to 16, Comparative Examples 1 to 6] Except for using each component of the types and compounding amounts (parts by mass) shown in Table 2, radiation-sensitive compositions of Examples 2 to 16 and Comparative Examples 1 to 6 were prepared in the same manner as in Example 1.

[0138]

Table 2

[0139] <Evaluation> Hardened films were formed from the radiation-sensitive compositions of Examples 1 to 16 and Comparative Examples 1 to 6, and the following items were evaluated by the method described below. The evaluation results are shown in Table 3 below.

[0140] [Radiation Sensitivity] On a 6-inch glass wafer, hexamethyldisilazane (HMDS) was applied using a spinner and heated at 60 °C for 1 minute (HMDS treatment). On the wafer after this HMDS treatment, each of the radiation-sensitive compositions prepared as described above was applied using a spinner. Then, after drying at 30 Pa for 1 second in a small-scale vacuum drying apparatus, a coating film with a film thickness of 3.0 μm was formed by pre-baking at 100 °C for 2 minutes. Subsequently, using an exposure machine ("MPA-600FA" manufactured by Canon: using an ultra-high pressure mercury lamp), the coating film was exposed through a mask having a rectangular exposure portion of 10 μm × 10 μm while changing the exposure amount. Then, development was carried out by the liquid puddle method at 25 °C with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide. The development time was 80 seconds. Next, rinsing was performed with ultrapure water for 1 minute by running water, and then drying was carried out to form a pattern on the wafer after HMDS treatment. The entire surface of the coating film was exposed at 300 mJ / cm 2 , and this wafer was heated in a clean oven at 230 °C for 30 minutes to perform post-baking to obtain a hardened film. The exposure amount required to form a 10 μm × 10 μm pattern during development was examined. It can be evaluated that the smaller the exposure amount, the better the radiation sensitivity. (Evaluation Criteria) AA: Less than 90 mJ / cm 2 A: 90 mJ / cm 2 ​120 mJ / cm or more 2 less than B: 120 mJ / cm 2 150 mJ / cm or more 2 less than C: 150 mJ / cm 2 or more

[0141] <Melt flow resistance> The cross-sectional shape of the coating film pattern resolved at the above optimal exposure dose was observed with a scanning electron microscope. At the endpoint where the coating film pattern contacts the substrate, a tangent line was drawn to the coating film pattern, and the angle formed by the tangent line and the substrate surface was calculated. The higher the angle, the better the melt flow resistance can be evaluated to be maintained even after heating at 230°C. (Evaluation criteria) AA: 70° or more A: 60° or more and less than 70° B: 40° or more and less than 60° C: less than 40°

[0142] <Relative permittivity> Using a spinner, after applying the radiation-sensitive composition on a glass substrate with ITO (indium tin oxide), it was pre-baked on a hot plate at 100°C for 2 minutes to form a coating film. The rotation speed of the spinner was adjusted so that the average film thickness after heating at 230°C for 30 minutes described later would be the coating film thickness of 3.0 μm. Then, it was developed by the liquid puddle method at 25°C with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide. The development time was 80 seconds. Next, it was rinsed with ultrapure water for 1 minute by running water and then dried. Using an exposure machine (Canon's "MPA-600FA": using an ultra-high pressure mercury lamp), the integrated irradiation dose was 300 mJ / cm 2The entire surface of the coating film was exposed so as to achieve this, and the exposed substrate was heated at 230 °C for 30 minutes in a clean oven, thereby forming a cured film on the ITO substrate. Subsequently, an aluminum electrode pattern was formed on the cured film by vapor deposition to fabricate a sample for dielectric constant measurement. For the substrate having this electrode pattern, a dielectric constant was measured at a frequency of 10 kHz using an electrode (Yokogawa and Hewlett-Packard's "HP16451B") and a precision LCR meter (Yokogawa and Hewlett-Packard's "HP4284A"). (Evaluation Criteria) AA: Less than 3.1 A: 3.1 or more and less than 3.4 B: 3.4 or more and less than 3.7 C: 3.7 or more

[0143] <Chemical Resistance> The cured film produced in the evaluation of the radiation sensitivity was immersed in N-methyl-2-pyrrolidone heated to 65 °C for 6 minutes, and after the immersion, the coating film was washed with running ultrapure water for 5 seconds and dried. The film thickness of the cured film after the treatment was measured using a stylus type film thickness meter. The N-methyl-2-pyrrolidone swelling ratio (%) was calculated according to the following formula, and the chemical resistance was evaluated according to the following criteria. N-methyl-2-pyrrolidone swelling ratio (%) = (P / Q - 1) × 100 [In the formula, P represents the remaining film (μm) after immersion, and Q represents the remaining film (μm) before immersion.] (Evaluation Criteria) AA: Less than 2% A: 2% or more and less than 4% B: 4% or more and less than 6% C: 6% or more

[0144]

Table 3

[0145] As shown in Table 3, each of the radiation-sensitive compositions of Examples 1 to 16 had good radiation sensitivity, melt flow resistance, relative permittivity, and chemical resistance as practical properties, and the balance of various properties was achieved. On the other hand, in Comparative Examples 1 to 6, any of the properties was evaluated as "C", and all were inferior to Examples 1 to 16.

Claims

1. A radiation-sensitive composition containing a quinonediazide compound (B), a solvent (C), wherein the polymer component (A) contains at least one structural unit (I) selected from the group consisting of a structural unit having an acid group and a structural unit derived from maleimide, a structural unit (II) containing an alicyclic epoxy group, and a structural unit (III) derived from a (meth)acrylate having an alicyclic structure (excluding the structural unit (II)), in the same polymer or different polymers, wherein the structural unit (II) is 10% by mass or more based on all the structural units constituting the polymer component (A), and the structural unit (III) is 10% by mass or more based on all the structural units constituting the polymer component (A). A radiation-sensitive composition.

2. The radiation-sensitive composition according to Claim 1, wherein the structural unit (II) is represented by the following formula (II-1), formula (II-2), or formula (II-3). 【Chemical 1】 (In formula (II-1) to formula (II-3), R １ is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, respectively. L １ is, independently of each other, a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms. n is an integer from 1 to 5. k1 is 0 or 1. X １ is independently a hydroxy group, a halogen atom, a cyano group, a nitro group, an alkyl group, or an alkoxy group, respectively. a1 is an integer from 0 to 3. When a1 is 2 or more, the plurality of Xs １ are the same as or different from each other.)

3. The radiation-sensitive composition according to Claim 1, wherein the alicyclic structure is a monocyclic alicyclic structure.

4. The radiation-sensitive composition according to Claim 1, wherein the (meth)acrylate having an alicyclic structure is cyclohexyl (meth)acrylate.

5. The radiation-sensitive composition according to Claim 1, wherein the polymer component (A) further contains a structural unit (IV) having an alkoxysilyl group.

6. The radiation-sensitive composition according to Claim 1, wherein the dielectric constant of the cured film formed by curing the radiation-sensitive composition at 10 kHz is less than 3.

4.

7. A method for producing a cured film, comprising: applying the radiation-sensitive composition according to any one of Claims 1 to 6 onto a substrate; removing the solvent from the applied radiation-sensitive composition; irradiating the radiation-sensitive composition from which the solvent has been removed with radiation; developing the radiation-sensitive composition irradiated with the radiation; and thermally curing the developed radiation-sensitive composition.

8. A cured film formed using the radiation-sensitive composition according to any one of Claims 1 to 6.

9. The cured film according to Claim 8, which is an interlayer insulating film or a planarizing film.

10. A display element comprising the cured film according to Claim 9.

11. The display element according to Claim 10, which is for organic EL.

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