JP2018004841A - Radiation-sensitive resin composition, pattern, method for forming pattern, and display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition having sufficient general characteristics such as resolution as a radiation-sensitive resin composition and capable of suppressing occurrence of exposure unevenness even when double exposure is induced, a pattern formed of the above radiation-sensitive resin composition and a method for forming the pattern, and a display element including the pattern.SOLUTION: The radiation-sensitive resin composition of the present invention comprises: a polymer having a first structural unit including an alicyclic hydrocarbon group having 5 to 30 carbon atoms, a phenyl group, a benzyl group or a combination of these groups; a radiation-sensitive polymerization initiator; and a polymerizable unsaturated compound. In the composition, the content of the first structural unit with respect to the whole structural units of the polymer is 5 mol% or more and 60 mol% or less.SELECTED DRAWING: None

Description

  The present invention relates to a radiation-sensitive resin composition, a pattern, a pattern forming method, and a display element.

  For display elements such as liquid crystal display elements, generally, a cured film patterned such as an interlayer insulating film, a spacer, a protective film, and a color filter coloring pattern is used. Such a cured film for a display element is required to have high surface hardness and light transmittance, and excellent chemical resistance.

  As such a cured film, that is, a pattern forming material, a radiation-sensitive resin composition is widely used because the number of steps for forming a pattern is small and a high surface hardness can be obtained (Japanese Patent Application Laid-Open (JP-A)). 2001-354822). The radiation-sensitive resin composition for pattern formation is generally required to have characteristics such as high sensitivity and resolution, few residues after development, and high adhesion after development.

  The formation of the pattern using the radiation-sensitive resin composition involves forming a coating film on the substrate using the radiation-sensitive resin composition, exposing the coating film, and developing the exposed coating film. Is done. As an exposure apparatus, a projection exposure apparatus that irradiates a coating film on a substrate with radiation from a light source via a photomask and a lens is used. On the other hand, in recent years, the area of display elements has been increased, and accordingly, it is desired to expand the exposure area in the exposure apparatus. In view of this, in the above projection exposure apparatus, for example, a scanning exposure apparatus having a plurality of illumination optical systems has been developed and put into practical use (JP-A-6-120108, JP-A-1-298719, JP-A No. (See JP 61-164126, JP 7-153683). In such a scanning exposure apparatus having a plurality of illumination optical systems, since the exposure range in one scan is wide, high-speed exposure of a large substrate is possible, and the productivity of display elements can be increased. . However, when a scanning exposure apparatus having a plurality of illumination optical systems is used, a portion where a plurality of lenses overlap can occur. On the coating film, the double exposure portion irradiated with the overlapping portion of the lens may be insufficiently cured, resulting in uneven exposure.

JP 2001-354822 A JP-A-6-120108 JP-A-1-298719 JP 61-164126 A JP-A-7-153683

  The present invention has been made on the basis of the circumstances as described above, and its purpose is sufficiently provided with general characteristics as a radiation-sensitive resin composition such as resolution, and when double exposure occurs. Furthermore, it is providing the radiation sensitive resin composition which can suppress generation | occurrence | production of exposure nonuniformity, the pattern formed from this radiation sensitive resin composition, its formation method, and a display element provided with the said pattern.

  The invention made in order to solve the above problems is a polymer having a first structural unit containing an alicyclic hydrocarbon group having 5 to 30 carbon atoms, a phenyl group, a benzyl group, or a combination thereof, and radiation sensitive polymerization initiation. A radiation-sensitive resin composition containing an agent and a polymerizable unsaturated compound, wherein the content of the first structural unit with respect to all the structural units of the polymer is 5 mol% or more and 60 mol% or less.

  Another invention made in order to solve the said subject is the pattern which is the hardened | cured material of the said radiation sensitive resin composition.

  Still another invention made in order to solve the above-mentioned problems is the step of forming a coating film on a substrate using the radiation-sensitive resin composition, the step of double exposing at least a part of the coating film, It is a pattern formation method provided with the process of developing a coating film, and the process of heating the said developed coating film.

  Still another invention made to solve the above-described problems is a display element having the pattern.

  The present invention has sufficient general characteristics as a radiation-sensitive resin composition such as resolution, and can suppress the occurrence of exposure unevenness even when double exposure occurs. Moreover, the pattern formed from this radiation sensitive resin composition, its formation method, and a display element provided with the said pattern can be provided. Therefore, according to the present invention, even when a part of an area on a substrate is subjected to multiple exposure and a pattern or the like is formed in the area, the exposure unevenness in the multiple exposure part can be reduced, and photolithography for a large substrate is performed. It can be used suitably for the manufacturing process of a display element etc., such as a process.

<Radiation sensitive resin composition>
The radiation-sensitive resin composition according to an embodiment of the present invention includes a first structural unit (hereinafter referred to as “structural unit”) containing an alicyclic hydrocarbon group having 5 to 30 carbon atoms, a phenyl group, a benzyl group, or a combination thereof. (I) ")) (hereinafter also referred to as" [A] polymer "), [B] radiation sensitive polymerization initiator (hereinafter also referred to simply as" [B] polymerization initiator "). And [C] a polymerizable unsaturated compound. [A] The content of the structural unit (I) with respect to all the structural units of the polymer is 5 mol% or more and 60 mol% or less.

  Since the radiation-sensitive resin composition has the above-described configuration, the occurrence of exposure unevenness can be suppressed even when double exposure occurs. The reason for this is not clear, but the following can be inferred. [A] polymer in the said radiation sensitive resin composition has structural unit (I) which has a side chain of a comparatively bulky hydrophobic cyclic structure in a predetermined content rate. For this reason, at the time of curing, it is possible to occupy the gap (the three-dimensional region having a reduced density) in the coating film that is generated along with the polymerization of the [C] polymerizable unsaturated compound so that the annular structure fills it. It is assumed that it can be done. As a result, it is presumed that curing shrinkage is effectively suppressed, and the difference in shrinkage between the normal exposure portion and the double exposure portion can be reduced.

  In addition to the [A] polymer, the [B] polymerization initiator, and the [C] polymerizable unsaturated compound, the radiation-sensitive resin composition includes other [D] adhesion assistants, [E] polymerization inhibitors, and the like. Ingredients can be included. However, each arbitrary component such as [D] adhesion assistant and [E] polymerization inhibitor may not be contained.

<[A] polymer>
[A] The polymer has the structural unit (I). [A] The polymer preferably further has a structural unit (II) to be described later, and can further have other structural units.

(Structural unit (I))
The structural unit (I) is not particularly limited as long as it includes an alicyclic hydrocarbon group having 5 to 30 carbon atoms, a phenyl group, a benzyl group, or a combination thereof, but is a structural unit represented by the following formula (1). It is preferable. The structural unit (I) may be composed of only one type of structural unit or may be composed of a plurality of types of structural units.

In Formula (1), R ^A is a hydrogen atom or a methyl group. X is a C5-C30 alicyclic hydrocarbon group, a phenyl group, or a benzyl group.

R ^A is a hydrogen atom or a methyl group, and is preferably a methyl group.

Examples of the alicyclic hydrocarbon group having 5 to 30 carbon atoms represented by X include, for example, a cyclopentyl group, a cyclohexyl group, a cycloheptanyl group, a cyclooctyl group, a cyclodecanyl group, a cyclododecanyl group, a cyclohexadecanyl group, and cycloicosane. A cycloalkyl group such as a group;
A cycloalkenyl group such as a cyclopentenyl group, a cyclohexenyl group, a cycloheptanyl group, a cyclooctenyl group, a cyclodecenyl group, a cyclododecenyl group;
A monovalent bridged ring hydrocarbon group such as a norbornyl group, an adamantyl group, a bicyclo [2.2.1] hept-2-enyl group, a tricyclo [5.2.1.0 ^2.6 ] decanyl group;
And monovalent groups having a spiro ring structure such as a spirobicyclopentanyl group.

  The upper limit of the carbon number of X is 30, but 20 is preferable, 16 is more preferable, 12 is more preferable, 12 is more preferable, 10 is particularly preferable, and 6 may be used. Moreover, although the minimum of the carbon number of said X is 5, 6 may be sufficient. By making the carbon number of X not more than the above upper limit, the hydrophobicity becomes more appropriate, and the resolution, developability and the like can be particularly improved. On the other hand, by setting the carbon number of X to the above lower limit or more, hydrophobicity can be increased, exposure unevenness suppressing ability, development adhesion, and the like can be improved.

  X is preferably a cyclopentyl group, a cyclohexyl group, a cycloheptanyl group, a cyclooctyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptanyl group, a cyclooctenyl group, or a norbornyl group. Among these, a cycloalkyl group (cyclopentyl group, cyclohexyl group, cycloheptanyl group, and cyclooctyl group) is more preferable, and a cyclohexyl group is particularly preferable.

Examples of the unsaturated compound that gives the structural unit (I) include cyclopentyl acrylate, cyclohexyl acrylate, cyclooctyl acrylate, cyclohexenyl acrylate, norbornyl acrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8-. Acrylic acid cyclic alkyl esters such as yl acrylate;
Methacrylic acid cyclic alkyl esters such as cyclopentyl methacrylate, cyclohexyl methacrylate, cyclooctyl methacrylate, cyclohexenyl methacrylate, norbornyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate;
Acrylic acid aryl esters such as phenyl acrylate and benzyl acrylate;
Examples thereof include methacrylic acid aryl esters such as phenyl methacrylate and benzyl methacrylate. The said unsaturated compound can be used individually by 1 type or in mixture of 2 or more types.

The structural unit (I) may be a structure other than the structure represented by the above formula (1). As a monomer unit giving such a structural unit (I),
Maleimide compounds such as N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide;
And unsaturated aromatic compounds such as styrene and α-methylstyrene.

  [A] The lower limit of the content of the structural unit (I) with respect to all the structural units of the polymer is 5 mol%, preferably 20 mol%, more preferably 30 mol%, still more preferably 35 mol%, further 40 mol% Is even more preferable. On the other hand, as this upper limit, it is 60 mol%, 55 mol% is preferable and 50 mol% is more preferable. When the content of the structural unit (I) is not less than the above lower limit, the hydrophobicity can be increased, and the ability to suppress exposure unevenness and the development adhesion can be increased. On the other hand, when the content of the structural unit (I) is not more than the above upper limit, good resolution, developability and the like can be exhibited.

(Structural unit (II))
The structural unit (II) is a structural unit represented by the following formula (2). The structural unit (II) is a structural unit having a three-membered cyclic ether structure (epoxy structure) in the side chain. [A] When the polymer has the structural unit (II), it is possible to improve the development adhesion, the hardness of the pattern obtained, the chemical resistance, and the like. The structural unit (II) may be composed of only one type of structural unit, or may be composed of a plurality of types of structural units.

In Formula (2), R ¹ is a hydrogen atom or a methyl group. R ² is an oxiranyl group (epoxy group), a 3,4-epoxycyclohexyl group, a group represented by the following formula (3-1), or a group represented by the following formula (3-2). X ¹ is a single bond, a methylene group or an alkylene group having 2 to 12 carbon atoms.

In formulas (3-1) and (3-2), * represents a binding site with X ¹ .

R ¹ is a hydrogen atom or a methyl group, preferably a methyl group.

Among the above R ² , a 3,4-epoxycyclohexyl group, a group represented by the above formula (3-1), and a group represented by the above formula (3-2) are preferable, and a 3,4-epoxycyclohexyl group is preferable. Is more preferable. When R ² has such a relatively bulky hydrophobic structure, the occurrence of uneven exposure due to double exposure can be further reduced due to the same effect as X in the structural unit (I).

X ¹ is a single bond, a methylene group or an alkylene group having 2 to 12 carbon atoms. Examples of the alkylene group having 2 to 12 carbon atoms (alkanediyl group) include an ethylene group and a propylene group. X ¹ is preferably a single bond or a methylene group (—CH ₂ —).

Examples of the unsaturated compound giving the structural unit (II) include glycidyl acrylate, 3,4-epoxycyclohexyl acrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxytricyclo [5.2.1.0 ^{2 , 6} ] acrylic ester such as decyl acrylate;
And methacrylic acid esters such as glycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, and 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decyl methacrylate. . The said unsaturated compound can be used individually by 1 type or in mixture of 2 or more types.

  [A] The lower limit of the content of the structural unit (II) with respect to all the structural units of the polymer is preferably 5 mol%, more preferably 10 mol%, and even more preferably 15 mol%. On the other hand, as this upper limit, 40 mol% is preferable, 30 mol% is more preferable, and 25 mol% is further more preferable. By making content of structural unit (II) more than the said minimum, the hardness of the pattern obtained, chemical-resistance, etc. can be improved more. On the other hand, by making this content below the upper limit, developability and the like can be improved.

(Structural unit (III))
[A] The polymer preferably further has a structural unit (III) having a carboxy group. [A] When the polymer has the structural unit (III), good developability with respect to an alkaline developer can be exhibited. Moreover, since the oxiranyl group of the structural unit (II) and the structural unit (III) undergo a crosslinking reaction, the hardness and chemical resistance of the pattern obtained can be further increased.

Examples of unsaturated compounds that give structural unit (III) include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, 4-vinylbenzoic acid;
Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid;
The anhydride of the said unsaturated dicarboxylic acid etc. are mentioned. The said unsaturated compound can be used individually by 1 type or in mixture of 2 or more types.

  [A] The lower limit of the content of the structural unit (III) with respect to all the structural units of the polymer is preferably 5 mol%, more preferably 10 mol%, and even more preferably 20 mol%. On the other hand, as this upper limit, 50 mol% is preferable, 40 mol% is more preferable, and 30 mol% is further more preferable. By making content of structural unit (III) more than the said minimum, a sensitivity, developability, the hardness of the cured film obtained, etc. can be made more favorable. On the contrary, by making this content not more than the above upper limit, a sufficient amount of the structural unit (I) can be contained, and therefore, development unevenness can be further reduced, development adhesion can be further improved, and the like. it can.

(Structural unit (IV))
[A] The polymer may further have structural units other than the above structural units (I) to (III).

Examples of unsaturated compounds that give structural unit (IV) include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, Methacrylic acid chain alkyl esters such as n-lauryl methacrylate, tridecyl methacrylate, n-stearyl methacrylate;
Methyl acrylate, ethyl acrylate, n-butyl acrylate, sec-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, isodecyl acrylate, n-lauryl acrylate, tridecyl acrylate, n-acrylate Acrylic acid chain alkyl esters such as stearyl;
Unsaturated dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate, diethyl itaconate;
unsaturated aromatic compounds such as m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene;
Conjugated dienes such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene;
Unsaturated compounds containing a tetrahydrofuran skeleton such as tetrahydrofurfuryl methacrylate, 2-methacryloyloxy-propionic acid tetrahydrofurfuryl ester, 3- (meth) acryloyloxytetrahydrofuran-2-one;
Other examples include acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, and vinyl acetate. The said unsaturated compound can be used individually by 1 type or in mixture of 2 or more types.

  [A] Although the minimum of content of structural unit (IV) with respect to all the structural units of a polymer is not specifically limited, 1 mol% is preferable and 5 mol% is more preferable. On the other hand, as this upper limit, 30 mol% is preferable, 20 mol% is more preferable, and 10 mol% is further more preferable. By setting the content of the structural unit (IV) within the above range, the ability to suppress exposure unevenness, the development performance, and the like are more effectively exhibited.

  [A] The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by GPC of the polymer is preferably 5,000, and more preferably 10,000. On the other hand, the upper limit is preferably 30,000, and more preferably 20,000. By making Mw more than the said lower limit, the film formability of the said radiation sensitive resin composition can be made favorable. On the other hand, by making Mw equal to or less than the above upper limit value, it is possible to prevent the developability of the radiation-sensitive resin composition from decreasing.

  As a minimum of the content rate of [A] polymer in the total solid in the said radiation sensitive resin composition, it can be set as 50 mass%, for example, and 55 mass% is preferable. On the other hand, as this upper limit, it can be 80 mass%, for example, and 70 mass% is preferable. [A] By controlling the content of the polymer within the above range, the ability to suppress exposure unevenness, development performance, and the like are more satisfactorily exhibited.

  [A] The polymer can be obtained by a known method such as radical polymerization in the presence of an appropriate solvent, a polymerization initiator, a chain transfer agent, etc., using an unsaturated compound that gives each structural unit.

<[B] Radiation sensitive polymerization initiator>
The radiation sensitive resin composition contains [B] a radiation sensitive polymerization initiator, so that [C] polymerizable unsaturated compound and the like can be obtained by irradiation with radiation (visible light, ultraviolet light, far ultraviolet light, etc.). Polymerization and curing can usually form a negative pattern.

  [B] Examples of the polymerization initiator (radiation sensitive polymerization initiator) include oxime ester compounds, acetophenone compounds, biimidazole compounds, and the like. These compounds may be used alone or in combination of two or more.

  As the oxime ester compound, an O-acyl oxime compound is typified. Specifically, for example, 1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), 1- (9-ethyl-6-benzoyl-9.H.-carbazole- 3-yl) -octane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-n-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate, ethanone-1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylbenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylbenzoyl) -9. H. -Carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-5-tetrahydrofuranylbenzoyl) -9. H. -Carbazole-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl } -9. H. -Carbazol-3-yl] -1- (O-acetyloxime) and the like.

Examples of oxime ester compounds include WO2016 / 017537, JP2015-93842, WO2012 / 132558, JP2011-132215, WO2009 / 081483, WO2008 / 077866, and JP2008-1007555. The described compounds can be used.
Examples of commercially available oxime ester compounds include NCI-831, NCI-930 (above, manufactured by ADEKA Corporation), DFI-020, DFI-091 (above, manufactured by Daito Chemix Corporation), Irgacure OXE01, OXE02, OXE03 (above. , Manufactured by BASF) or the like can also be used.

  Examples of acetophenone compounds include α-aminoketone compounds and α-hydroxyketone compounds.

  Examples of the α-aminoketone compound include 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4 -Morpholin-4-yl-phenyl) -butan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, and the like.

  Examples of the α-hydroxyketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1- (4-i-propylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone and the like can be mentioned.

  Examples of the biimidazole compound include 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4 -Dichlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole or 2,2'-bis (2,4,6-trichlorophenyl) -4,4', 5,5 Examples include '-tetraphenyl-1,2'-biimidazole.

  [B] Among these, an oxime ester compound is preferable as the polymerization initiator.

  [B] As a minimum of content of a polymerization initiator, 1 mass part is preferred to 3 mass parts of [A] polymer, 3 mass parts are more preferred, and 5 mass parts are still more preferred. On the other hand, as this upper limit, 20 mass parts is preferable and 10 mass parts is more preferable. [B] By making the content rate of a polymerization initiator into the said range, favorable sclerosis | hardenability etc. can be exhibited.

  In particular, when the polymerization initiator [B] is an oxime ester compound, the lower limit of the content of the oxime ester compound with respect to 100 parts by mass of the polymer [A] is preferably 3 parts by mass, and more preferably 5 parts by mass. Moreover, as an upper limit of this content, 10 mass parts or less are preferable. Thus, by using the oxime ester compound in a content within the above range as the [B] polymerization initiator, the ability to suppress uneven exposure, the development performance, and the like are more satisfactorily exhibited.

<[C] polymerizable unsaturated compound>
[C] The polymerizable unsaturated compound is usually a compound having a plurality of polymerizable groups. Examples of the polymerizable group include a group containing a carbon-carbon unsaturated double bond such as a vinyl group and a (meth) acryloyl group. [C] As a polymerizable unsaturated compound, polyfunctional (meth) acrylic acid ester, such as bifunctional (meth) acrylic acid ester and (meth) acrylic acid ester more than trifunctional, can be illustrated.

  Examples of the bifunctional (meth) acrylic acid ester include ethylene glycol di (meth) acrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetra Examples include ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, tricyclodecane methanol diacrylate, and the like. It is done.

  Examples of the trifunctional or higher functional (meth) acrylic acid ester include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetra Methacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, ethylene oxide modified dipentaerythritol hexaacrylate, Li (2-acryloyloxyethyl) phosphate, tri (2-methacryloyloxyethyl) phosphate, succinic acid modified pentaerythritol triacrylate, side chain acryloyl group bis F resin, succinic acid modified dipentaerythritol pentaacrylate, A compound having a chain alkylene group and an alicyclic structure and having two or more isocyanate groups, and one or more hydroxy groups in the molecule, and 3, 4, or 5 (meta And polyfunctional urethane acrylate compounds obtained by reacting with a compound having an acryloyloxy group.

  [C] The lower limit of the content of the polymerizable unsaturated compound with respect to 100 parts by mass of the [A] polymer is preferably 30 parts by mass, more preferably 40 parts by mass, further preferably 50 parts by mass, and even more preferably 60 parts by mass. preferable. On the other hand, the upper limit of the content is preferably 80 parts by mass, and more preferably 70 parts by mass. In the radiation sensitive resin composition, it is preferable to relatively reduce the content of the [C] polymerizable unsaturated compound with respect to the [A] polymer. In this case, even when the [C] polymerizable unsaturated compound is polymerized and cured, the shrinkage of the film accompanying the polymerization can be suppressed, and the difference in shrinkage between the normal exposure portion and the double exposure portion can be reduced. [C] By making content of a polymerizable unsaturated compound more than the said minimum, a sensitivity, resolution, the chemical resistance of the pattern obtained, etc. can be improved. On the other hand, by setting the content of the [C] polymerizable unsaturated compound to the upper limit or less, it is possible to effectively reduce the occurrence of exposure unevenness.

<[D] Adhesion aid>
[D] The adhesion assistant is a component that improves the adhesion between the obtained pattern (cured film) and the substrate. [D] As the adhesion assistant, a functional silane coupling agent having a reactive functional group such as a carboxy group, a methacryloyl group, a vinyl group, an isocyanate group, or an oxiranyl group is preferable.

  Examples of the functional silane coupling agent include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, and 3-glycidyloxypropyl. Examples include trimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (methacryloyloxy) ethyl phosphate, and the like.

  [D] The lower limit of the content of the adhesion assistant is preferably 0.01 parts by weight, more preferably 0.1 parts by weight, and further 0.5 parts by weight with respect to 100 parts by weight of the polymer [A]. preferable. On the other hand, as this upper limit, 10 mass parts is preferable, 5 mass parts is more preferable, and 2 mass parts is further more preferable.

<[E] Polymerization inhibitor>
[E] The polymerization inhibitor can increase the storage stability of the radiation-sensitive resin composition. [E] Examples of the polymerization inhibitor include sulfur, quinones, hydroquinones, polyoxy compounds, amines, nitronitroso compounds, and more specifically, p-methoxyphenol, 2,5-di-t-. Examples thereof include butylhydroquinone and N-nitroso-N-phenylhydroxylamine aluminum.

  The upper limit of the content of the [E] polymerization inhibitor in the radiation sensitive resin composition is preferably 0.5 parts by mass, more preferably 0.3 parts by mass with respect to 100 parts by mass of the [A] polymer. 0.2 part by mass is more preferable. [E] When the content of the polymerization inhibitor exceeds the above upper limit, the sensitivity of the radiation-sensitive resin composition may be lowered, and the pattern shape may be deteriorated. In addition, the minimum of content of this [E] polymerization inhibitor can be 0.01 mass part, for example.

<Other ingredients>
The said radiation sensitive resin composition can further contain other components other than the [A]-[E] component mentioned above. Examples of such other components include, in addition to the solvents described later, antioxidants, surfactants, chain transfer agents, polymers other than the [A] polymer, and the like. The said radiation sensitive resin composition may use said each component individually or in combination of 2 or more types. The upper limit of the total content of the components other than the components [A] to [E] and [F] is, for example, 10% by mass, 5% by mass, and 1% by mass. %.

<Antioxidant>
The antioxidant is a component capable of decomposing radicals generated by exposure or heating, or peroxide generated by oxidation, and preventing the bond breakage of the polymer molecules. As a result, the pattern obtained can be prevented from oxidative deterioration over time, and for example, changes in the film thickness of the pattern can be suppressed.

  Examples of the antioxidant include a compound having a hindered phenol structure, a compound having a hindered amine structure, a compound having an alkyl phosphite structure, and a compound having a thioether structure.

<Surfactant>
A surfactant is a component that improves film-forming properties. Examples of the surfactant include a fluorine-based surfactant, a silicone-based surfactant, and other surfactants.

<Chain transfer agent>
The chain transfer agent is a component that improves film forming properties. Examples of the chain transfer agent include thiol chain transfer agents and aromatic chain transfer agents.

<Method for preparing radiation-sensitive resin composition>
In the radiation-sensitive resin composition, the [A] polymer, the [B] polymerization initiator, the [C] polymerizable unsaturated compound, and other components as necessary are mixed at a predetermined ratio, preferably appropriate. [F] can be prepared by dissolving in a solvent. The prepared radiation-sensitive resin composition is preferably filtered through, for example, a filter having a pore diameter of about 0.2 μm. As solid content concentration of the said radiation sensitive resin composition, it is 10 to 50 mass%, for example.

<[F] solvent>
As the [F] solvent used for the preparation of the radiation-sensitive resin composition, a solvent that uniformly dissolves or disperses each component contained in the radiation-sensitive resin composition and does not react with the respective components is used.

[F] Examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, butanol and octanol;
Esters such as ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate;
Ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene diglycol monomethyl ether, ethylene diglycol ethyl methyl ether;
Amides such as dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; Aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene be able to.

  [F] As the solvent, esters are preferred. [F] A solvent can be used 1 type or in mixture of 2 or more types.

<Pattern>
The pattern (cured film) according to one embodiment of the present invention is a cured product of the radiation-sensitive resin composition. Since the said pattern is formed from the said radiation sensitive resin composition, there are few exposure nonuniformities and it has a uniform film thickness. The pattern also has good characteristics such as surface hardness, light transmittance, and chemical resistance. The pattern having such characteristics is used for, for example, an interlayer insulating film, a planarizing film, a bank for defining a region for forming a light emitting layer, a spacer, a protective film, a color filter for an electronic device such as a display element. It can be used for coloring patterns. In particular, the pattern can be suitably applied to a large screen display element. The pattern formation method is not particularly limited, but it is preferable to apply the pattern formation method described below.

<Pattern formation method>
A pattern forming method according to an embodiment of the present invention includes:
(1) A step of forming a coating film on a substrate using the radiation-sensitive resin composition (hereinafter also referred to as “step (1)”),
(2) a step of double exposing at least a part of the coating film (hereinafter also referred to as “step (2)”),
(3) Step of developing the coating film (hereinafter also referred to as “step (3)”), and (4) Step of heating the developed coating film (hereinafter also referred to as “step (4)”).
Is provided.

  Since the pattern forming method uses a scanning exposure apparatus for exposure, high-speed exposure of a large substrate is possible, and productivity of a display element such as a flat panel display can be improved. In addition, since the radiation-sensitive resin composition has the above-mentioned properties, even when a part of the region on the substrate is subjected to multiple exposure and a pattern or the like is formed in the region, the multiple exposure portion The exposure unevenness at can be reduced. The multiple exposure portion may be, for example, a double exposure portion, more than that, or a mixture thereof. Hereinafter, each process is explained in full detail.

[Step (1)]
In this step, a coating film is formed on the substrate using the radiation-sensitive resin composition. Specifically, the radiation-sensitive resin composition in the form of a solution is applied to the substrate surface, and preferably a prebake is performed to remove the solvent and form a coating film. Examples of the substrate include a glass substrate, a silicon substrate, a plastic substrate, and a substrate on which various metal thin films are formed. Examples of the plastic substrate include a resin substrate made of plastic such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethersulfone, polycarbonate, polyimide, and the like.

  As a coating method, for example, an appropriate method such as a spray method, a roll coating method, a spin coating method (spin coating method), a slit die coating method, a bar coating method, or an ink jet method can be employed. Of these, spin coating, bar coating, and slit die coating are preferred as the coating method. The pre-baking conditions vary depending on the type of each component, the use ratio, and the like, but can be, for example, 60 ° C. or higher and 130 ° C. or lower and 30 seconds or longer and 10 minutes or shorter. The film thickness of the coating film to be formed is preferably 0.1 μm or more and 8 μm or less as a value after pre-baking.

[Step (2)]
In this step, a part of the coating film is irradiated with radiation. Specifically, the coating film formed in step (1) is irradiated with radiation through a mask having a predetermined pattern. Examples of the radiation used at this time include ultraviolet rays, far ultraviolet rays, X-rays, and charged particle beams. At this time, a part of the coating film is irradiated with radiation twice. That is, in this step, a part of the coating film is subjected to double exposure.

Examples of the ultraviolet rays include g-line (wavelength 436 nm), i-line (wavelength 365 nm), and the like. Examples of the far ultraviolet light include KrF excimer laser light. Examples of X-rays include synchrotron radiation. Examples of the charged particle beam include an electron beam. Among these radiations, ultraviolet rays are preferable, and among the ultraviolet rays, radiation containing g-line, h-line and / or i-line is more preferable. The exposure dose of radiation is preferably 0.1 J / m ² or more and 20,000 J / m ² or less.

  In this step, a scanning exposure apparatus is preferably used as the radiation irradiation apparatus. A scanning exposure apparatus having a plurality of illumination optical systems has, for example, a plurality of illumination optical systems and a plurality of projection optical systems (a plurality of lenses) arranged corresponding to each of the plurality of illumination optical systems. . The scanning exposure apparatus having the plurality of illumination optical systems irradiates a plurality of irradiated areas on the photomask with light beams (radiation) from the plurality of illumination optical systems, and the plurality of irradiated areas. Is projected onto the coating film on the substrate via the plurality of projection optical systems. Further, exposure may be performed by a method other than a scanning exposure apparatus having a plurality of illumination optical systems.

[Step (3)]
In this step, the coating film irradiated with the radiation is developed. In the pattern forming method, the negative development is usually performed. Specifically, the coating film irradiated with radiation in the step (2) is developed with a developing solution to remove the non-irradiated part of the radiation. Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylaminoethanol, di-n-propylamine, triethylamine, methyl Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo Examples thereof include an aqueous solution of an alkali (basic compound) such as [4,3,0] -5-nonane. Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the aqueous alkali solution, or an alkaline aqueous solution containing a small amount of various organic solvents capable of dissolving the radiation-sensitive resin composition It may be used as

  As a developing method, for example, an appropriate method such as a liquid piling method, a dipping method, a rocking dipping method, or a shower method can be employed. The development time varies depending on the composition of the radiation sensitive resin composition, but can be, for example, 30 seconds or longer and 120 seconds or shorter. In addition, it is preferable to perform the rinse process etc. by running water washing | cleaning with respect to the patterned coating film after a image development process.

[Step (4)]
In this step, the developed coating film is heated. Although it does not specifically limit as a heating method, For example, it can heat using heating apparatuses, such as oven and a hotplate. As heating temperature in this process, it can be set as 120 to 250 degreeC, for example. The heating time varies depending on the type of heating equipment, but for example, when heat treatment is performed on a hot plate, it is 5 minutes to 40 minutes, and when heat treatment is performed in an oven, it is 30 minutes to 80 minutes. be able to. In this manner, a desired pattern (patterned cured film) such as an interlayer insulating film can be formed on the substrate.

<Display element>
A display element according to an embodiment of the present invention includes the pattern. Examples of the display element include a liquid crystal display element and a plasma display. In these display elements, the pattern is used as, for example, an interlayer insulating film that insulates between wirings, a spacer, a protective film, a color filter coloring pattern, or the like. Since the display element includes the pattern, the display element is excellent in general characteristics required for practical use.

  In the liquid crystal display element which is an example of the display element, for example, two TFT array substrates having a liquid crystal alignment film formed on the surface are arranged on the liquid crystal alignment film side through a sealant provided in the peripheral portion of the TFT array substrate. The liquid crystal is filled between these two TFT array substrates. The TFT array substrate has wirings arranged in layers, and the wirings are insulated by the pattern as an interlayer insulating film.

<Other embodiments>
The present invention is not limited to the embodiment described above. For example, the radiation sensitive resin composition can be suitably used in a pattern forming method using an exposure apparatus other than a scanning exposure apparatus having a plurality of illumination optical systems.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In addition, the characteristic of the polymer obtained by the synthesis example was measured with the following method.

[Weight average molecular weight (Mw), number average molecular weight (Mn) and dispersity (Mw / Mn)]
Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) under the following analytical conditions using Tosoh GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL). The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.

(Analysis conditions)
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Column temperature: 40 ° C
Detector: Differential refractometer Standard material: Monodisperse polystyrene

[ ¹³ C-NMR analysis]
^{The 13} C-NMR analysis was performed using an analytical instrument (“JNM-EX400” manufactured by JEOL Ltd.) using deuterated chloroform as a measurement solvent. The content rate of each structural unit was computed as mol% from the area ratio of the peak corresponding to each structural unit in the spectrum obtained by < ¹³ > C-NMR analysis.

<[A] Synthesis of polymer>
Hereinafter, in each synthesis example and comparative synthesis example, the compound (A1) is a monomer that provides the structural unit (I), the compound (A2) is a monomer that provides the structural unit (II), and the compound (A3) is a structural unit. The monomer that provides (III), and the compound (A4) is a monomer that provides the structural unit (IV).

[Synthesis Example 1] (Synthesis of polymer (A-1))
A flask equipped with a condenser and a stirrer was charged with 5.2 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate 50 parts by mass, (A2) glycidyl methacrylate 20 parts by mass, (A3) methacrylic acid 20 parts by mass, (A4) methyl After 10 parts by weight of methacrylate and 0.5 parts by weight of α-methylstyrene dimer as a chain transfer agent were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (A-1) (solid content concentration = 33.5 mass%, Mw = 15,100 , Mw / Mn = 2.0). As a result of ¹³ C-NMR analysis, the content of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) was 30.9 mol%, 21.5 mol%, and 31 respectively. 0.8 mol% and 15.8 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound were 5.1 mol% and 1.3 mol, respectively, with respect to 100 mol% of the charged monomers. Mol%, 2.1 mol% and 2.9 mol%. The content of the unreacted compound was determined by ¹ H-NMR, ¹³ C-NMR, FT-IR, and pyrolysis gas chromatography mass spectrometry (hereinafter the same).

[Synthesis Example 2] (Synthesis of polymer (A-2))
A flask equipped with a condenser and a stirrer was charged with 3.6 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate 50 parts by mass, (A2) 3,4-epoxycyclohexylmethyl methacrylate 25 parts by mass, (A3) methacrylic acid 22 parts by mass Parts, (A4) 3 parts by mass of methyl methacrylate, and 0.5 parts by mass of α-methylstyrene dimer were charged with nitrogen, and then gently stirring was started. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (A-2) (solid content concentration = 33.0 mass%, Mw = 14,2000). , Mw / Mn = 2.1). As a result of ¹³ C-NMR analysis, the contents of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) were 34.1 mol%, 20.8 mol%, and 36, respectively. 0.1 mol% and 9.0 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound are 1.0 mol% and 1.9 mol, respectively, with respect to 100 mol% of the charged monomers. Mol%, 2.1 mol% and 2.1 mol%.

[Synthesis Example 3] (Synthesis of Polymer (A-3))
A flask equipped with a condenser and a stirrer was charged with 5.0 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, 50 parts by mass of (A1) tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, (A2) 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] After 15 parts by mass of decyl acrylate, (A3) 20 parts by mass of methacrylic acid, (A4) 15 parts by mass of methyl methacrylate, and 0.5 parts by mass of α-methylstyrene dimer were charged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (A-3) (solid content concentration = 33.7% by mass, Mw = 14,300). Mw / Mn = 1.9). As a result of ¹³ C-NMR analysis, the content of the structural unit (I), the structural unit (II), the structural unit (III) and the structural unit (IV) was 32.8 mol%, 10.3 mol% and 34, respectively. 0.1 mol% and 22.8 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound are 0.8 mol% and 2.4 mol, respectively, with respect to 100 mol% of the charge of each monomer. Mol%, 1.2 mol% and 0.9 mol%.

[Synthesis Example 4] (Synthesis of Polymer (A-4))
A flask equipped with a condenser and a stirrer was charged with 5.5 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) cyclohexyl methacrylate 55 parts by mass, (A2) glycidyl methacrylate 20 parts by mass, (A3) methacrylic acid 16 parts by mass, (A4) methyl methacrylate 9 parts by mass, and α-methylstyrene dimer 0.5 parts by mass. After charging and replacing with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (A-4) (solid content concentration = 34.2% by mass, Mw = 13,800). , Mw / Mn = 2.0). As a result of ¹³ C-NMR analysis, the contents of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) were 43.1 mol%, 20.5 mol%, and 24, respectively. .2 mol% and 12.2 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound were 2.5 mol% and 0.8 mol, respectively, with respect to 100 mol% of the charged monomers. Mol%, 2.1 mol% and 1.3 mol%.

[Synthesis Example 5] (Synthesis of Polymer (A-5))
A flask equipped with a condenser and a stirrer was charged with 5.1 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) cyclohexyl methacrylate 55 parts by mass, (A2) 3,4-epoxycyclohexylmethyl methacrylate 25 parts by mass, (A3) methacrylic acid 16 parts by mass, (A4) methyl methacrylate 4 parts by mass, and α-methylstyrene dimer After 0.5 part by mass was charged and replaced with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (A-5) (solid content concentration = 33.6% by mass, Mw = 14,200). , Mw / Mn = 2.1). As a result of ¹³ C-NMR analysis, the contents of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) were 47.2 mol%, 19.5 mol%, and 26, respectively. .2 mol% and 7.1 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound are 1.5 mol% and 2.2 mol, respectively, with respect to 100 mol% of the charged monomers. Mol%, 1.8 mol% and 0.3 mol%.

[Synthesis Example 6] (Synthesis of Polymer (A-6))
A flask equipped with a condenser and a stirrer was charged with 5.1 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) 55 parts by mass of benzyl methacrylate, (A2) 20 parts by mass of glycidyl methacrylate, (A3) 16 parts by mass of methacrylic acid, (A4) 9 parts by mass of methyl methacrylate, and 0.5 parts by mass of α-methylstyrene dimer. After charging and replacing with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-6) (solid content concentration = 33.2% by mass, Mw = 14, 000, Mw / Mn = 2.2). As a result of ¹³ C-NMR analysis, the contents of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) were 44.1 mol%, 19.9 mol%, and 24, respectively. 0.1 mol% and 11.9 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound are 2.8 mol% and 1.4 respectively for 100 mol% of the charged monomers. Mol%, 0.3 mol%, and 2.4 mol%.

[Synthesis Example 7] (Synthesis of Polymer (A-7))
A flask equipped with a condenser and a stirrer was charged with 5.1 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) 55 parts by mass of benzyl methacrylate, (A2) 25 parts by mass of 3,4-epoxycyclohexylmethyl methacrylate, (A3) 16 parts by mass of methacrylic acid, (A4) 4 parts by mass of methyl methacrylate, and α-methylstyrene dimer After 0.5 part by mass was charged and replaced with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-7) (solid content concentration = 33.0 mass%, Mw = 15, 400, Mw / Mn = 2.0). As a result of ¹³ C-NMR analysis, the content of the structural unit (I), the structural unit (II), the structural unit (III) and the structural unit (IV) was 45.9 mol%, 20.1 mol%, 26 And 2 mol% and 7.8 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound were 2.1 mol% and 2.5 mol, respectively, with respect to 100 mol% of the charge of each monomer. Mol%, 0.9 mol% and 0.5 mol%.

[Synthesis Example 8] (Synthesis of polymer (A-8))
A flask equipped with a condenser and a stirrer was charged with 6.2 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate 25 parts by mass, (A2) glycidyl methacrylate 20 parts by mass, (A3) methacrylic acid 16 parts by mass, (A4) methyl After 39 parts by weight of methacrylate and 0.5 parts by weight of α-methylstyrene dimer were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (a-4) (solid content concentration = 33.5% by mass, Mw = 12,800). Mw / Mn = 2.2). As a result of ¹³ C-NMR analysis, the contents of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) were 13.1 mol%, 18.3 mol%, 21 0.1 mol% and 47.5 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound, and (A4) compound are 1.8 mol% and 0.00%, respectively, with respect to 100 mol% of the charge of each monomer. They were 8 mol%, 2.1 mol%, and 3.2 mol%.

[Comparative Synthesis Example 1] (Synthesis of polymer (a-1))
A flask equipped with a condenser and a stirrer was charged with 7.0 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) 63 parts by mass of styrene, (A2) 17 parts by mass of glycidyl methacrylate, (A3) 16 parts by mass of methacrylic acid, (A4) 4 parts by mass of methyl methacrylate, and 0.5 parts by mass of α-methylstyrene dimer were charged. After the atmosphere was replaced with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (a-1) (solid content concentration = 29.5 mass%, Mw = 11,800). , Mw / Mn = 1.8). As a result of ¹³ C-NMR analysis, the content of structural unit (I), structural unit (II), structural unit (III) and structural unit (IV) was 61.0 mol%, 14.3 mol%, 19 And 3 mol% and 5.4 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound and (A4) compound are 15.0 mol% and 2.4 mol, respectively, with respect to 100 mol% of the charged monomers. Mol%, 0.8 mol% and 1.1 mol%.

[Comparative Synthesis Example 2] (Synthesis of polymer (a-2))
A flask equipped with a condenser and a stirrer was charged with 7.1 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A2) 20 parts by mass of glycidyl methacrylate, (A3) 12 parts by mass of methacrylic acid, (A4) 68 parts by mass of methyl methacrylate, and 0.5 parts by mass of α-methylstyrene dimer were charged with nitrogen, and then gently Stirring started. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (a-2) (solid content concentration = 33.1% by mass, Mw = 14,200). Mw / Mn = 1.9). As a result of ¹³ C-NMR analysis, the contents of structural unit (II), structural unit (III) and structural unit (IV) were 15.2 mol%, 14.1 mol% and 70.7 mol%, respectively. It was. Further, the contents of the unreacted (A2) compound, (A3) compound, and (A4) compound were 3.1 mol%, 1.2 mol%, and 2 respectively with respect to 100 mol% of the charge of each monomer. It was 2 mol%.

[Comparative Synthesis Example 3] (Synthesis of polymer (a-3))
A flask equipped with a condenser and a stirrer was charged with 7.1 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1 ′) n-lauryl methacrylate 60 parts by mass, (A2) glycidyl methacrylate 20 parts by mass, (A3) methacrylic acid 14 parts by mass, (A4) methyl methacrylate 6 parts by mass, and α-methylstyrene dimer 0.5 Stirring was started gently after charging a mass part and replacing with nitrogen. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (a-3) (solid content concentration = 32.5 mass%, Mw = 13,300). , Mw / Mn = 2.1). As a result of ¹³ C-NMR analysis, the content of the structural unit (I ′), the structural unit (II), the structural unit (III) and the structural unit (IV) was 38.1 mol%, 24.8 mol%, They were 26.1 mol% and 11.0 mol%. Further, the contents of the unreacted (A1 ′) compound, (A2) compound, (A3) compound, and (A4) compound are 5.1 mol%, 2 .2 mol%, 0.8 mol%, and 1.1 mol%.

[Comparative Synthesis Example 4] (Synthesis of polymer (a-4))
A flask equipped with a condenser and a stirrer was charged with 6.2 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate 25 parts by mass, (A2) glycidyl methacrylate 20 parts by mass, (A3) methacrylic acid 16 parts by mass, (A4) methyl After 39 parts by weight of methacrylate and 0.5 parts by weight of α-methylstyrene dimer were charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (a-4) (solid content concentration = 33.5% by mass, Mw = 12,800). Mw / Mn = 2.2). As a result of ¹³ C-NMR analysis, the contents of the structural unit (I), the structural unit (II), the structural unit (III), and the structural unit (IV) were 13.1 mol%, 18.3 mol%, 21 0.1 mol% and 47.5 mol%. Further, the contents of the unreacted (A1) compound, (A2) compound, (A3) compound, and (A4) compound are 1.8 mol% and 0.00%, respectively, with respect to 100 mol% of the charge of each monomer. They were 8 mol%, 2.1 mol%, and 3.2 mol%.

[Comparative Synthesis Example 5] (Synthesis of polymer (a-5))
A flask equipped with a condenser and a stirrer was charged with 6.2 parts by mass of 2,2′-azobis- (2,4-dimethylvaleronitrile) and 200 parts by mass of methyl 3-methoxypropionate. Subsequently, (A1) tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate 85 parts by mass, (A2) glycidyl methacrylate 5 parts by mass, (A3) methacrylic acid 10 parts by mass, and α-methyl After 0.5 parts by mass of styrene dimer was charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the polymer (a-5) (solid content concentration = 33.2% by mass, Mw = 12,900). Mw / Mn = 2.2). As a result of ¹³ C-NMR analysis, the contents of the structural unit (I), the structural unit (II), and the structural unit (III) were 70.7 mol%, 7.2 mol%, and 22.1 mol%, respectively. there were. Further, the contents of the unreacted (A1) compound, (A2) compound, and (A3) compound are 1.1 mol%, 1.9 mol%, and 100 mol%, respectively, with respect to 100 mol% of the charged monomers. It was 2.2 mol%.

Table 1 shows the types and charge ratios (mass ratio) of the monomers used in the above synthesis examples and comparative synthesis examples, and the contents (molar ratio) of each structural unit in the obtained polymer. In addition, each monomer in Table 1 is as follows.
A1-1: Tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate A1-2: Cyclohexyl methacrylate A1-3: Benzyl methacrylate A1-4: Styrene A2-1: Glycidyl methacrylate A2-2: 3,4-epoxycyclohexylmethyl methacrylate A2-3: 3,4-epoxytricyclo [5.2.1.0 ^2,6 ] decyl acrylate A3-1: methacrylic acid A4-1: methyl methacrylate A1′-1: n-Lauryl methacrylate

<Preparation of radiation-sensitive resin composition>
[A] polymer, [B] polymerization initiator, [C] polymerizable unsaturated compound, [D] adhesion assistant, [E] polymerization used for the preparation of the radiation sensitive resin compositions of Examples and Comparative Examples Inhibitors and [F] solvents are shown below.

<[A] polymer>
A-1 to A-8: Polymers (A-1) to (A-8) synthesized in Synthesis Examples 1 to 8, respectively.
a-1 to a-5: Polymers (a-1) to (a-5) respectively synthesized in Comparative Synthesis Examples 1 to 5

<[B] Polymerization initiator>
B-1: O-acyl oxime compound (“NCI-930” from ADEKA)
B-2: 1- [4- (Phenylthio) -2- (O-benzoyloxime)] ("Irgacure OXE01" from BASF)
B-3: O-acyl oxime compound ("Irgacure OXE03" from BASF)
B-4: Ethanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime) ("Irgacure OXE02" from BASF)

<[C] polymerizable unsaturated compound>
C-1: Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (“KAYARAD DPHA” from Nippon Kayaku Co., Ltd.)
C-2: 1,9-nonanediol diacrylate (“Light acrylate 1,9ND-A” from Kyoeisha Chemical Co., Ltd.)
C-3: Tricyclodecane methanol diacrylate (“NK Ester A-DCP” from Shin-Nakamura Chemical Co., Ltd.)

<[D] Adhesion aid>
D-1: Methacryloxypropyltrimethoxysilane ("XIAMETER (R) OFS-6030 SILANE" manufactured by Toray Dow Corning)

<[E] Polymerization inhibitor>
E-1: 2,5-di-t-butylhydroquinone (Wako Pure Chemical Industries, Ltd.)

<[F] solvent>
F-1: Methyl 3-methoxypropionate F-2: Propylene glycol monomethyl ether acetate

<Example 1>
In the solution containing the polymer (A-1), 1 part by weight of a polymerization initiator (B-1) and a polymerization initiator with respect to an amount corresponding to 100 parts by weight (solid content) of the polymer (A-1). (B-2) 1 part by mass, polymerizable unsaturated compound (C-1) 65 parts by mass, adhesion assistant (D-1) 1 part by mass, and polymerization inhibitor (E-1) 0.1 part by mass After being mixed and dissolved in a mixed solvent (mass ratio 1: 1) of the solvent (F-1) and the solvent (F-2) so that the solid content concentration becomes 30% by mass, the membrane having a pore size of 0.2 μm It filtered with the filter and the radiation sensitive resin composition (S-1) was prepared.

<Examples 2 to 17 and Comparative Examples 1 to 5>
For [A] polymer, [B] polymerization initiator and [C] polymerizable unsaturated compound, the same operation as in Example 1 was carried out except that the components of the types and blending amounts shown in Table 2 below were used. The radiation sensitive resin compositions (S-2) to (S-17) and (CS-1) to (CS-5) were prepared. In Table 2, “-” indicates that the corresponding component was not blended.

<Evaluation>
A cured film is formed from the radiation-sensitive resin compositions of Examples 1 to 17 and Comparative Examples 1 to 5, and the radiation sensitivity, resolution, residue, development adhesion, and double exposure part stability are determined according to the methods described below. Chemical resistance and light transmittance were evaluated. The evaluation results are shown in Table 2.

[Radiation sensitivity]
After applying the radiation sensitive resin composition on a glass substrate using a spinner, it was pre-baked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 4.0 μm. Next, using an exposure machine ("PLA-501F" manufactured by Canon Inc .: using an ultra-high pressure mercury lamp), the amount of exposure was changed, and the coating film was passed through a pattern mask having a plurality of rectangular light shielding portions (10 μm × 10 μm). Exposure was performed. Next, a development process was performed at 25 ° C. by a liquid piling method using a tetramethylammonium hydroxide aqueous solution (developer) having a concentration of 2.38 mass%. The development processing time was 100 seconds. After the development treatment, the coating film was washed with running ultrapure water for 1 minute and dried to form a pattern on the glass substrate. This glass substrate was heated in a clean oven at 230 ° C. for 30 minutes to obtain a cured film. With respect to the thickness of the cured film, the exposure amount at which the remaining film ratio (ratio in which the patterned thin film is appropriately left) represented by the following formula was 85% or more was obtained as sensitivity, and the sensitivity was evaluated according to the following criteria.
Residual film ratio (%) = (film thickness after development / film thickness before development) × 100

(Evaluation criteria)
A: 200J / ^{m 2} less B: 200J / ^{m 2} or more 400 J / ^{m 2} less than C: 400J / ^{m 2} or more 800 J / ^{m 2} less than D: 800J / ^{m 2} or more

[Resolution]
A cured film having a through hole was formed in the same manner as the evaluation of radiation sensitivity except that the exposure amount was 200 J / m ^2, and the minimum diameter of the through hole of this cured film was observed with an optical microscope. The resolution was evaluated according to the following criteria.

(Evaluation criteria)
A: Minimum diameter of the through hole is 10 μm or more B: Minimum diameter of the through hole is 8 μm or more and less than 10 μm C: Minimum diameter of the through hole is 5 μm or more and less than 8 μm D: No through hole is formed

[Residue]
A cured film having a through hole was formed in the same manner as the evaluation of radiation sensitivity except that the exposure amount was 200 J / m ^2, and the through hole of the cured film was observed with an optical microscope. The residue was evaluated according to the following criteria.

(Evaluation criteria)
A: A residue cannot be confirmed B: A residue can be confirmed slightly C: A residue can be confirmed clearly D: A residue can be confirmed in large quantities

[Development adhesion]
Curing was performed in the same manner as the evaluation of radiation sensitivity except that a mask having a line-and-space ratio (L / S) of 1: 1 (line width and space width of 40-5 μm) was used and the exposure amount was 200 J / m ^2. A film was formed. About this cured film, the minimum width | variety of the line which remains without peeling after image development was observed with the optical microscope, and image development adhesiveness was evaluated according to the following references | standards.

(Evaluation criteria)
A: Minimum width is less than 10 μm B: Minimum width is 10 μm or more and less than 30 μm C: Minimum width is 30 μm or more D: All peeled

[Double exposure area stability]
Using a mask with a line-and-space ratio (L / S) of 4: 1 (line width is 400 μm, space width is 100 μm), exposure is performed once at an exposure amount of 200 J / m ² or at an exposure amount of 100 J / m ² . A cured film was formed in the same manner as in the evaluation of radiation sensitivity except that the exposure was performed twice. The film thickness difference between the cured film exposed once at an exposure amount of 200 J / m ² and the cured film exposed twice at an exposure amount of 100 J / m ² was calculated, and the stability of the double-exposed area was evaluated according to the following criteria.

(Evaluation criteria)
A: Film thickness difference is less than 0.10 μm B: Film thickness difference is 0.10 μm or more and less than 0.20 μm C: Film thickness difference is 0.20 μm or more and less than 0.30 μm D: Film thickness difference is 0.30 μm or more

[Chemical resistance]
The cured film prepared by the above-described evaluation of radiation sensitivity was immersed in N-methyl-2-pyrrolidone heated to 65 ° C. for 6 minutes. After immersion, the coating film was washed with running ultrapure water for 5 seconds and dried. . The thickness of the insulating film after the treatment was measured using a stylus type film thickness meter. N-methyl-2-pyrrolidone swelling rate (%) was calculated according to the following formula, and chemical resistance was evaluated according to the following criteria.
N-methyl-2-pyrrolidone swelling rate (%)
= (Remaining film after immersion (μm) / Residual film before immersion (μm) −1) × 100

(Evaluation criteria)
A: Less than 3% B: 3% or more and less than 5% C: 5% or more and less than 7% D: 7% or more

[Light transmittance]
After applying the radiation sensitive resin compositions prepared in Examples 1 to 17 and Comparative Examples 1 to 5 on a glass substrate (Corning “Corning 7059”) using a spinner, on a hot plate And prebaked at 90 ° C. for 2 minutes to form a coating film. Next, exposure was performed using a Canon “PLA-501F” exposure machine (extra-high pressure mercury lamp), and development was performed using an aqueous tetramethylammonium hydroxide solution having a concentration of 2.38% by mass. Furthermore, the cured film with a film thickness of 3.0 micrometers was obtained by heating at 230 degreeC for 30 minutes. About the glass substrate in which this cured film was formed, the light transmittance in the wavelength range of 400 nm to 800 nm was measured using a spectrophotometer (“150-20 type double beam” manufactured by Hitachi, Ltd.). The minimum value of the light transmittance in the wavelength range of 400 nm to 800 nm (also referred to as the minimum light transmittance) was evaluated. Table 2 shows the minimum light transmittance.

  Each radiation sensitive resin composition of Examples 1-17 is evaluation in which double exposure part stability is any of AC, and generation | occurrence | production of the nonuniformity when double exposure arises can fully be suppressed. Recognize. In addition, each of the radiation sensitive resin compositions of Examples 1 to 17 has any one of A to C in terms of evaluation of resolution. That is, it turns out that the radiation sensitive resin composition of Examples 1-17 has double exposure part stability and resolution. In particular, each of the radiation-sensitive resin compositions of Examples 1 to 14 has all of radiation sensitivity, residue, development adhesion, chemical resistance, and light transmittance in addition to the above-mentioned double exposure portion stability and resolution. It is evaluation in any of AC, and it turns out that it has especially various characteristics as a radiation sensitive resin composition for pattern formation of a display element. On the other hand, the radiation sensitive resin compositions of Comparative Examples 1 to 5 have an evaluation of D in at least one of the double exposure portion stability and the resolution. The radiation-sensitive resin compositions of Comparative Examples 1 to 5 cannot suppress the occurrence of uneven exposure when double exposure occurs, or do not have both double exposure part stability and resolution. I understand that.

The radiation sensitive resin composition of the present invention can be suitably used as a cured film forming material for display elements such as an interlayer insulating film. In particular, the radiation-sensitive resin composition can be suitably used as a photosensitive material in the case of exposing a large substrate (for example, a 2200 mm × 2500 mm 10 generation substrate) with a scanning exposure apparatus.

Claims (8)

A polymer having a first structural unit containing an alicyclic hydrocarbon group having 5 to 30 carbon atoms, a phenyl group, a benzyl group, or a combination thereof;
Containing a radiation sensitive polymerization initiator, and a polymerizable unsaturated compound,
The radiation sensitive resin composition whose content of the said 1st structural unit with respect to all the structural units of the said polymer is 5 mol% or more and 60 mol% or less. The first structural unit is represented by the following formula (1):
The content of the first structural unit with respect to all the structural units of the polymer is 20 mol% or more and 60 mol% or less,
The radiation-sensitive resin composition according to claim 1, wherein the content of the polymerizable unsaturated compound with respect to 100 parts by mass of the polymer is 30 parts by mass or more and 80 parts by mass or more.

(In Formula (1), ^RA is a hydrogen atom or a methyl group. X is a C5-C30 alicyclic hydrocarbon group, a phenyl group, or a benzyl group.)   X in said Formula (1) is a C5-C8 alicyclic hydrocarbon group, The radiation sensitive resin composition of Claim 2. The radiation-sensitive resin composition according to claim 1, wherein the polymer further has a second structural unit represented by the following formula (2).

(In Formula (2), R ¹ is a hydrogen atom or a methyl group. R ² is an oxiranyl group, a 3,4-epoxycyclohexyl group, a group represented by the following Formula (3-1), or the following formula: X ³ is a single bond, a methylene group or an alkylene group having 2 to 12 carbon atoms.)

(In formulas (3-1) and (3-2), * represents a binding site with X ^1. ) The radiation sensitive polymerization initiator is an oxime ester compound,
The radiation-sensitive resin composition according to any one of claims 1 to 4, wherein a content of the oxime ester compound with respect to 100 parts by mass of the polymer is 3 parts by mass or more and 10 parts by mass or less.   The pattern which is a hardened | cured material of the radiation sensitive resin composition of any one of Claims 1-5. A step of forming a coating film on a substrate using the radiation-sensitive resin composition according to any one of claims 1 to 5,
A step of double exposing at least a part of the coating film;
The pattern formation method provided with the process of developing the said coating film, and the process of heating the said developed coating film. A display element comprising the pattern according to claim 6.