Method for forming pattern on laminate and composition used therefor

Abstract

A resist underlayer film-forming composition for forming a resist underlayer film disposed between a substrate and a light-absorbing resist film, the resist underlayer film-forming composition comprising: an alkali-soluble resin; particles having light reflecting properties and / or light scattering properties; and a solvent, wherein the resist underlayer film is formed by firing the resist underlayer film-forming composition, exhibits dissolving agent resistance to a dissolving agent contained in a resist material for forming the light-absorbing resist film, and exhibits solubility to an alkaline developing solution for the light-absorbing resist film.

Description

Method for forming a pattern on a laminate and composition used therein

[0001] The present invention relates to a method for forming a pattern on a laminate and a composition used therein, and more particularly to a method for forming a pattern on a laminate, a composition for forming a resist underlayer film, a resist underlayer film, a laminate, and a self-luminous display device.

[0002] Conventionally, anti-reflection circular polarizers have been used in self-luminous display elements such as organic light-emitting diodes (OLEDs) and micro LEDs. However, the use of polarizers reduces brightness due to light absorption by the polarizers. In recent years, there has been a trend toward not using anti-reflection circular polarizers. Instead of using anti-reflection circular polarizers, display devices have been proposed that suppress reflection of external light and improve brightness by providing light-absorbing partition walls made of black material in an area surrounding the display area (see, for example, Patent Documents 1 and 2).

[0003] As a material used for manufacturing partition walls of such display devices, an inkjet ink for forming partition walls has been proposed (see Patent Documents 3 and 4). Furthermore, a substrate with partition walls having predetermined optical properties has been proposed (see Patent Document 5).

[0004] Japanese Patent Application Laid-Open No. 2005-317271 Japanese Patent Application Laid-Open No. 2023-518514 International Publication No. 2023 / 079620 International Publication No. 2023 / 079622 Japanese Patent Application Laid-Open No. 2021-113977

[0005] To form black pixel partitions as shown in Patent Documents 1 and 2, a method is used in which a black resist material made by mixing a black material with a photosensitive resin is used, the black resist material is applied to a substrate, and then the black resist is patterned through exposure and development steps.

[0006] Incidentally, some pixel partitions are composed of a white partition and a black partition above it (see, for example, FIGS. 1C and 2C of Patent Document 3 and FIGS. 1B and 2B of Patent Document 4). No method is known for efficiently manufacturing, using a resist material, such a partition composed of overlapping partitions of two different colors.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a composition for forming a resist underlayer film, which enables a fine structure constituted by overlapping fine structures of two different colors to be efficiently produced using a resist material; a resist underlayer film formed from the composition for forming a resist underlayer film; a laminate using the resist underlayer film; a method for forming a pattern of the laminate; and a self-luminous display element.

[0008] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, and have completed the present invention having the following gist.

[0009] That is, the present invention encompasses the following aspects. [1] A composition for forming a resist underlayer film for forming a resist underlayer film disposed between a substrate and a light-absorbing resist film, the composition for forming a resist underlayer film comprising an alkali-soluble resin, particles having at least one of light reflectivity and light scattering property, and a solvent, and the resist underlayer film formed by baking the composition for forming a resist underlayer film exhibits solvent resistance to solvents contained in a resist material for forming the light-absorbing resist film and exhibits solubility in an alkaline developer for the light-absorbing resist film. [2] The composition for forming a resist underlayer film according to [1], wherein the alkali-soluble resin is a polyamic acid. [3] The composition for forming a resist underlayer film according to [1] or [2], which contains a crosslinking agent. [4] The composition for forming a resist underlayer film according to [3], wherein the crosslinking agent is an epoxy compound. [5] The composition for forming a resist underlayer film according to any one of [1] to [4], which contains a development rate modifier. [6] The composition for forming a resist underlayer film according to [5], wherein the development rate modifier is a compound containing a phenolic hydroxyl group or a carboxy group. [7] The composition for forming a resist underlayer film according to any one of [1] to [6], wherein the particles are metal particles, a white organic pigment, or a white inorganic pigment. [8] The composition for forming a resist underlayer film according to [7], wherein the particles are a white inorganic pigment, and the white inorganic pigment is selected from titanium dioxide, zirconium oxide, zinc oxide, calcium carbonate, and barium sulfate. [9] The composition for forming a resist underlayer film according to any one of [1] to [8], wherein the light-absorbing resist film is a black resist film.

[10] A resist underlayer film that is a cured film of the composition for forming a resist underlayer film according to any one of [1] to [9].

[11] The resist underlayer film according to

[10] , which is non-photosensitive.

[12] A laminate comprising a substrate, the resist underlayer film according to

[10] or

[11] , and a light-absorbing resist film.

[13] The laminate according to

[12] , wherein the resist underlayer film has a solvent resistance developing temperature set to be lower than a developer insolubilization temperature of the resist underlayer film in an alkaline developer for the light-absorbing resist film.

[14] A method for forming a pattern of a laminate, comprising: forming a resist underlayer film on a substrate using the composition for forming a resist underlayer film according to any one of [1] to [9], forming a light-absorbing resist film on the resist underlayer film, and exposing the light-absorbing resist film to light, and developing the light-absorbing resist film in a desired portion and the resist underlayer film formed under the light-absorbing resist film in the desired portion, thereby obtaining a pattern of the laminate.

[15] The method for forming a laminate pattern according to

[14] , wherein baking performed during the formation of the resist underlayer film is performed under temperature conditions between a temperature at which the resist underlayer film exhibits solvent resistance to a solvent contained in a resist material for forming the light-absorbing resist film and a temperature at which the resist underlayer film becomes insolubilized in an alkaline developer.

[16] The method for forming a laminate pattern according to

[14] or

[15] , wherein the light-absorbing resist film is formed using a black pigment dispersed resist material.

[17] A laminate formed by the method for forming a laminate pattern according to any one of

[14] to

[16] .

[18] A self-luminous display element having the laminate according to

[17] .

[0010] According to the present invention, it is possible to provide a composition for forming a resist underlayer film, which enables a fine structure composed of overlapping fine structures of two different colors to be efficiently produced using a resist material, a resist underlayer film formed from the composition for forming a resist underlayer film, a laminate using the resist underlayer film, a method for forming a pattern of the laminate, and a self-luminous display element.

[0011] Fig. 1 is a graph showing the relationship between the baking temperature of a resist underlayer film and the degree of solvent resistance exhibited by the resist underlayer film as a result of the baking, and the relationship between the baking temperature of a resist underlayer film and the degree of insolubilization in a developer exhibited by the resist underlayer film as a result of the baking. Fig. 2 is a schematic diagram showing the relationship between the baking temperature and the dissolution of a resist underlayer film in a developer. Fig. 3 is an SEM image of a laminate on which a line / space pattern is formed.

[0012] (Composition for forming a resist underlayer film) The composition for forming a resist underlayer film of the present invention contains an alkali-soluble resin, particles having at least one of light reflectivity and light scattering properties, and a solvent. The resist underlayer film formed by baking the composition for forming a resist underlayer film of the present invention exhibits solvent resistance to solvents contained in the resist material for forming the light-absorbing resist film and exhibits solubility in an alkaline developer for the light-absorbing resist film. The composition for forming a resist underlayer film of the present invention may also contain a crosslinking agent, a development rate adjuster, etc. The composition for forming a resist underlayer film of the present invention is a composition for forming a resist underlayer film disposed between a substrate and a light-absorbing resist film. By using a specific resist underlayer film formed from the composition for forming a resist underlayer film of the present invention, the light-absorbing resist film formed on the resist underlayer film can be exposed and developed, and the resist underlayer film can also be patterned when the light-absorbing resist is patterned. Here, the light-absorbing resist film and the resist underlayer film are two different colors. That is, by using the composition for forming a resist underlayer film of the present invention, a fine structure composed of overlapping fine structures of two different colors can be produced by a single patterning.

[0013] A patterned resist underlayer film formed from the composition for forming a resist underlayer film and a patterned resist film formed from the light-absorbing resist film can be suitably used, for example, as a partition wall of a display element. In this respect, the composition for forming a resist underlayer film can be referred to as, for example, a composition for forming a partition wall.

[0014]

[0042] <Alkali-Soluble Resin> As long as the resist underlayer film formed by baking the resist underlayer film-forming composition of the present invention containing an alkali-soluble resin exhibits solvent resistance to the solvent contained in the resist material for forming the light-absorbing resist film and exhibits solubility in an alkaline developer for the light-absorbing resist film, the alkali-soluble resin is not particularly limited and can be appropriately selected depending on the purpose. It is more preferred that the alkali-soluble resin is a polyamic acid.

[0015] <<Polyamic Acid>> The polyamic acid that is the alkali-soluble resin according to the present invention is preferably a polyamic acid having a repeating unit represented by the following formula (1).

[0016] (R １ is a tetravalent organic group constituting a tetracarboxylic acid or a derivative thereof, and R ２ is a divalent organic group constituting a diamine, and k is a natural number.

[0017] The method for obtaining this polyamic acid is not particularly limited, but it can generally be obtained by reacting and polymerizing a diamine with a tetracarboxylic acid or its derivatives such as a tetracarboxylic acid dianhydride or a dicarboxylic acid dihalide, etc. Also, a method that usually can be used is to react and polymerize a diamine with a tetracarboxylic acid dianhydride (hereinafter abbreviated as acid dianhydride) in a polar solvent such as N-methylpyrrolidone.

[0018] The diamines that can be used to obtain polyamic acid are not particularly limited, and may be used alone or in combination of two or more. Specific examples include p-phenylenediamine, m-phenylenediamine, 4,4-methylene-bis(2,6-ethylaniline), 4,4'-methylene-bis(2-isopropyl-6-methylaniline), 4,4'-methylene-bis(2,6-diisopropylaniline), 2,4,6-trimethyl-1,3-phenylenediamine, 2,3,5,6-tetramethyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3',5,5'- Tetramethylbenzidine, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]hexafluoropropane, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diaminodiphenyl ether, 3,4-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aniline) Hexafluoropropane, 2,2-bis(3-anilino)hexafluoropropane, 2,2-bis(3-amino-4-toluyl)hexafluoropropane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,5-bis(4-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,10-bis(4-aminophenoxy)deca Examples of suitable diamines include bis[4-(4-aminophenoxy)phenyl]sulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 3,5-diaminobenzoic acid, 4-aminobenzoic acid-4-aminophenyl, and 4,4'-diaminobenzanilide. It is also preferable to use a siloxane-containing diamine to enhance adhesion to the substrate. Examples of suitable siloxane-containing diamines include the following diamines:

[0019] (wherein p represents an integer of 1 to 10)

[0020] The acid dianhydride that can be used to obtain the polyamic acid is not particularly limited, and one or more of these may be used simultaneously. Specific examples of the acid dianhydride include aromatic tetracarboxylic acid dianhydrides such as pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, and 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride. In addition, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid dianhydride, Examples of the tetracarboxylic acid dianhydride include hydrates, alicyclic tetracarboxylic acid dianhydrides such as 2,3,5-tricarboxy-2-cyclopentaneacetic acid dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride and 3,5,6-tricarboxy-2-norbornane acetic acid dianhydride, and aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butane tetracarboxylic acid dianhydride.

[0021] In terms of the solubility of the polyamic acid resin coating film in an alkaline developer, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenetetracarboxylic acid dianhydride, Acid dianhydrides consisting of tetracarboxylic acids in which four carbonyl groups are not directly bonded to aromatic rings, such as lenthrin succinic dianhydride, 2,3,5-tricarboxy-2-cyclopentane acetic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, and 3,5,6-tricarboxy-2-norbornane acetic dianhydride, are preferred, and 1,2,3,4-cyclobutane tetracarboxylic dianhydride is more preferred.

[0022] In the polymerization of polyamic acid, the ratio of the total number of moles of diamine to the total number of moles of acid dianhydride is preferably 0.8 to 1.2. As with ordinary polycondensation reactions, the closer this molar ratio is to 1, the higher the degree of polymerization of the resulting polymer. If the degree of polymerization is too low, the film strength will be insufficient. On the other hand, if the degree of polymerization is too high, workability during film production may be impaired. Therefore, the degree of polymerization of the product in the present invention is preferably such that the reduced viscosity is 0.05 to 5.0 dl / g (in N-methylpyrrolidone at a temperature of 30°C, at a concentration of 0.5 g / dl). In particular, the reduced viscosity is preferably 0.2 to 2.0 dl / g. Examples of polar solvents that can be used when reacting a diamine and an acid dianhydride in a polar solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-vinylpyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, m-cresol, γ-butyrolactone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monoethyl ether, and propylene glycol mono-n-propyl ether. These may be used alone or in combination. Furthermore, even if a solvent does not dissolve polyamic acid, it may be mixed with the above solvent as long as the polyamic acid produced by the polymerization reaction does not precipitate. The reaction temperature between the diamine and the acid dianhydride can be selected from the range of −20 to 150°C, preferably −5 to 100°C. The polyamic acid thus obtained can be used as it is, or can be recovered and used after isolation by precipitation in a poor solvent such as methanol, ethanol, or water.

[0023] The content of the alkali-soluble resin in the composition for forming a resist underlayer film is not particularly limited, but is preferably 10% by mass to 95% by mass, and more preferably 20% by mass to 90% by mass, based on the film-constituting components. The film-constituting components refer to components other than the solvent in the composition for forming a resist underlayer film.

[0024] <Particles Having at Least Either Light Reflectivity or Light Scattering Properties> Particles having at Least Either light reflectivity or light scattering properties (hereinafter, sometimes referred to as "specific particles") are not particularly limited. When the particles contained in the composition for forming a resist underlayer film have at Least Either light reflectivity or light scattering properties, at Least Either light reflectivity or light scattering properties are imparted to the resist underlayer film formed from the composition for forming a resist underlayer film. A resist underlayer film having at Least Either light reflectivity or light scattering properties (e.g., a white resist underlayer film) is less likely to absorb light. For example, the partition walls of a self-luminous display element formed from the resist underlayer film are less likely to absorb emitted light, and therefore, the brightness and the efficiency of external extraction of emitted light can be improved.

[0025] Examples of the specific particles include metal particles and white pigments, and examples of the white pigments include white inorganic pigments and white organic pigments.

[0026] Examples of metal particles include gold, silver, aluminum, iron, and platinum.

[0027] The white organic pigment is a white pigment primarily composed of an organic compound. Generally, organic pigments are pigments containing organic compounds as components, but in this embodiment, the organic compounds also include silicone resins. Preferably, the white organic pigment contains powder of one or more types selected from the group consisting of fluororesin, silicone resin, acrylic resin, and urethane resin. The shape of the particles constituting the powder is not particularly limited, but is preferably spherical, more preferably true spherical.

[0028] Examples of white inorganic pigments include titanium dioxide (TiO ２ ), aluminum oxide (Al ２ O ３ ), tin oxide (SnO ２ ), iron oxide (Fe ２ O ３ ), zinc oxide (ZnO), magnesium oxide (MgO), zirconium oxide (ZrO ２ ), cerium oxide (CeO ２ ), lithium oxide (Li ２ O), silver oxide (AgO), antimony oxide (Sb２ O ３ , Sb ２ O ５ ), calcium oxide (CaO), calcium carbonate (CaCO ３ ), barium sulfate (BaSO ４ Among these, titanium dioxide (TiO ２ ), zinc oxide (ZnO), zirconium oxide (ZrO ２ ), calcium carbonate (CaCO ３ ), and barium sulfate (BaSO ４ ) is preferred.

[0029] The white pigment may be C. I. Pigment White. Examples of C. I. Pigment White include C. I. Pigment White 4, 5, 6, 6:1, 7, 18, 18:1, 19, 20, 22, 25, 26, 27, 28, and 32.

[0030] The specific particles may be, for example, treated. For example, titanium dioxide as the specific particles may be subjected to, as necessary, a resin treatment, a surface treatment using a pigment derivative into which an acidic group or a basic group has been introduced, a grafting treatment to the pigment surface using a polymer compound, a micronization treatment using a sulfuric acid micronization method, a washing treatment using an organic solvent or water to remove impurities, a treatment to remove ionic impurities using an ion exchange method, or the like. For example, titanium dioxide (TiO ２ ) has its surface covered with silicon oxide (SiO ２ ), aluminum oxide (Al ２ O ３ ), zirconium oxide (ZrO ２ ), and organic substances, and preferably silicon oxide (SiO ２ ), aluminum oxide (Al ２ O ３ ), and zirconium oxide (ZrO ２ ), and more preferably, surface-treated titanium oxide (TiO ２The outermost surface of the titanium dioxide (TiO) nanoparticles can be treated with an organic substance. ２ ) coating and surface treatment, titanium oxide (TiO ２ ) and titanium dioxide (TiO ２ The additive is not particularly limited as long as it prevents the particles from being compressed and agglomerated. In one or more embodiments, stearic acid, trimethylpropane (TMP), pentaerythritol, etc. may be used.

[0031] The average particle size of the specific particles is not particularly limited, but is preferably 100 nm to 1,000 nm, and more preferably 100 nm to 800 nm. The average particle size is a median size measured by a laser diffraction / scattering method or a dynamic light scattering method.

[0032] The content of the specific particles in the composition for forming a resist underlayer film is not particularly limited, but is preferably 5% by mass to 200% by mass, and more preferably 10% by mass to 100% by mass, relative to the alkali-soluble resin.

[0033] <Solvent> The composition for forming a resist underlayer film of the present invention can be easily prepared by uniformly mixing the components, and is used in the form of a solution dissolved in a suitable solvent. Examples of such solvents that can be used include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. These solvents can be used alone or in combination of two or more kinds. Furthermore, high boiling point solvents such as propylene glycol monobutyl ether and propylene glycol monobutyl ether acetate can be mixed and used.

[0034] The solution of the composition for forming a resist underlayer film is preferably filtered using a filter appropriately selected depending on the solution to be used, and then used. The pore size of the filter may be, for example, about 5 μm.

[0035] The content of the solvent in the composition for forming a resist underlayer film is not particularly limited, but is preferably 40% by mass to 99% by mass, more preferably 45% by mass to 97% by mass, and particularly preferably 50% by mass to 95% by mass.

[0036] <Material Properties of the Composition for Forming a Resist Underlayer Film> The composition for forming a resist underlayer film of the present invention can change the developer dissolution rate of the resist underlayer film in an alkaline developer for a light-absorbing resist film by changing the temperature conditions of the baking performed when forming the resist underlayer film. The composition for forming a resist underlayer film of the present invention exhibits properties, for example, as shown in Figure 1 depending on the baking temperature. Figure 1 is a graph showing the degree of solvent resistance and the degree of insolubilization in a developer of the resist underlayer film after baking at different baking temperatures. In Figure 1, the degree of resistance of the resist underlayer film to a solvent contained in the resist material for forming the light-absorbing resist film is indicated by symbol A. Furthermore, in Figure 1, the degree of insolubilization of the resist underlayer film in a developer is indicated by symbol B. For example, when the resist underlayer film-forming composition contains a polyamic acid, as indicated by a1 in the broken line of symbol A, the resist underlayer film obtained by baking the resist underlayer film-forming composition of the present invention at a temperature of a1 or higher exhibits increased resistance to the solvents contained in the resist material due to the onset of imidization and crosslinking reactions. Up to a2, the higher the baking temperature, the higher the solvent resistance. At temperatures a2 and above, the solvent resistance reaches an acceptable level. The resist underlayer film obtained by baking at a2 or above does not undergo mixing even when a light-absorbing resist material is applied onto the resist underlayer film. Here, the baking temperature a2 is also referred to as the "solvent resistance onset temperature" of the resist underlayer film against the solvents contained in the light-absorbing resist material. On the other hand, as indicated by b1 in the broken line of symbol B, in the resist underlayer film obtained by baking the composition for forming a resist underlayer film of the present invention at a temperature of b1 or higher, an imidization reaction or a crosslinking reaction begins, and as the imidization or crosslinking progresses, the proportion of carboxylic acid in the composition decreases, thereby increasing the degree of insolubilization of the resist underlayer film in an alkaline developer. Note that if the baking temperature is b2 or higher, the resist underlayer film becomes insoluble in the developer. Here, the baking temperature of b2 is also referred to as the "developer insolubilization temperature" of the resist underlayer film in an alkaline developer.

[0037] In the present invention, it is preferable to use a composition for forming a resist underlayer film in which the "solvent resistance developing temperature" is set lower than the "developer insolubilization temperature." Furthermore, in the present invention, it is preferable that the baking performed when forming the resist underlayer film is performed under temperature conditions between the "solvent resistance developing temperature" and the "developer insolubilization temperature" (corresponding to the temperature range indicated by symbol T in FIG. 1 ). A preferable baking temperature is, for example, around 130°C to 220°C when the composition for forming a resist underlayer film contains a polyamic acid. Note that baking will also be described below in the section on the method for forming a laminate pattern, etc.

[0038] As described above, the resist underlayer film-forming composition of the present invention may contain, in addition to the alkali-soluble resin and solvent, a crosslinking agent, a development speed modifier, and the like. The crosslinking agent and development speed modifier are described in detail below. For example, when the resist underlayer film-forming composition contains a polyamic acid as the alkali-soluble resin and an epoxy compound as the crosslinking agent, baking the resist underlayer film-forming composition causes a portion of the polyamic acid to be imidized, and another portion to react with the epoxy compound. By adjusting the content of the polyamic acid, the content of the epoxy compound, the content of the development speed modifier, and the like, which are subjected to the imidization reaction in the resist underlayer film-forming composition, it is possible to adjust the interval between the "solvent resistance exhibiting temperature" and the "developer insolubilization temperature" (corresponding to the temperature range indicated by symbol T in FIG. 1 ) and the slope of the developer dissolution rate of the resist underlayer film (corresponding to the slope from b1 to b2 in the broken line indicated by symbol B in FIG. 1 ). The wider the interval between the "solvent resistance exhibiting temperature" and the "developer insolubilizing temperature" (corresponding to the temperature range indicated by symbol T in FIG. 1 ), the easier the handling of the resist underlayer film when it is produced. Furthermore, the smaller the slope of the dissolution rate of the resist underlayer film in the developer (corresponding to the slope from b1 to b2 in the broken line indicated by symbol B in FIG. 1 ), the wider the temperature margin. Furthermore, in the present invention, the slope of the dissolution rate of the resist underlayer film in the developer (corresponding to the slope from b1 to b2 in the broken line indicated by symbol B in FIG. 1 ) can be adjusted by adding a development speed adjuster to the composition for forming the resist underlayer film.

[0039] <Crosslinking Agent> The composition for forming a resist underlayer film of the present invention may contain a crosslinking agent in addition to the alkali-soluble resin, specific particles, and solvent. Examples of the crosslinking agent include epoxy compounds. Such compounds are not particularly limited as long as they have an epoxy group. For example, examples of compounds having at least two epoxy groups include tris(2,3-epoxypropyl)isocyanurate, 1,4-butanediol diglycidyl ether, 1,2-epoxy-4-(epoxyethyl)cyclohexane, glycerol triglycidyl ether, diethylene glycol diglycidyl ether, 2,6-diglycidylphenyl glycidyl ether, 1,1,3-tris[p-(2,3-epoxypropoxy)phenyl]propane, 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 4,4'-methylenebis(N,N-diglycidylaniline), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, trimethylolethane triglycidyl ether, bisphenol-A diglycidyl ether, and pentaerythritol polyglycidyl ether. Furthermore, polymers having epoxy groups can also be used as compounds having at least two epoxy groups. Such polymers can be used without particular limitation as long as they have epoxy groups. Such polymers can be produced by addition polymerization using an addition-polymerizable monomer having an epoxy group, or by reacting a polymer compound having a hydroxyl group with a compound having an epoxy group, such as epichlorohydrin or glycidyl tosylate. Examples of such polymers include addition-polymerized polymers such as polyglycidyl methacrylate, a copolymer of glycidyl methacrylate and ethyl methacrylate, a copolymer of glycidyl methacrylate, styrene, and 2-hydroxyethyl methacrylate, and poly(3,4-epoxycyclohexylmethyl methacrylate), as well as condensation-polymerized polymers such as epoxy novolac. The weight-average molecular weight of such polymers is, for example, 300 to 200,000.

[0040] Examples of compounds having at least two epoxy groups include Sumiepoxy ELM434 and Sumiepoxy ELM434L (manufactured by Sumitomo Chemical Co., Ltd.), which are epoxy resins having an amino group; Epolead GT-401, GT-403, GT-301, GT-302, Celloxide 2021, and Celloxide 3000 (manufactured by Daicel Corporation), which are epoxy resins having a cyclohexene oxide structure; JER1001, JER1002, JER1003, JER1004, JER1007, JER1009, JER1010, and JER828 (all manufactured by Mitsubishi Chemical Corporation), which are bisphenol A epoxy resins; and bisphenol F epoxy resins. phenol novolac epoxy resins such as JER152 and JER154 (all manufactured by Mitsubishi Chemical Corporation), EPPN201 and EPPN202 (all manufactured by Nippon Kayaku Co., Ltd.), cresol novolac epoxy resins such as EOCN-102, EOCN-103S, EOCN-104S, EOCN-1020, EOCN-1025 and EOCN-1027 (all manufactured by Nippon Kayaku Co., Ltd.) and JER180S75 (manufactured by Mitsubishi Chemical Corporation), alicyclic epoxy resins such as Denacol EX-252 (manufactured by Nagase Chemtex Corporation), CY175, CY177 and CY179 (all manufactured by CIBA-GEIGY) AG), Araldite CY-182, CY-192, CY-184 (all manufactured by CIBA-GEIGY AG), Epiclon 200, 400 (all manufactured by Dainippon Ink Mfg. Co., Ltd.), JER871, JER872 (all manufactured by Mitsubishi Chemical Corporation), ED-5661, ED-5662 (all manufactured by Celanese Coatings Co., Ltd.), and the like, together with aliphatic polyglycidyl ethers such as Denacol EX-611, EX-612, EX-614, EX-62 2, EX-411, EX-512, EX-522, EX-421, EX-313, EX-314, and EX-321 (manufactured by Nagase Chemtex Corporation), and triazine epoxy compounds such as TEPIC-S, TEPIC-SS, TEPIC-HS, TEPIC-VL, and TEPIC-FL (manufactured by Nissan Chemical Industries, Ltd.).The content of the epoxy group-containing compound is, for example, 70 parts by mass or less, preferably 50 parts by mass or less, and more preferably 45 parts by mass or less, relative to 100 parts by mass of the alkali-soluble resin. If the content of the epoxy group-containing compound is more than 70 parts by mass, sufficient solubility in the photoresist developer may not be obtained.

[0041] The content of the crosslinking agent in the composition for forming a resist underlayer film is not particularly limited, but is, for example, 70% by mass or less, and preferably 50% by mass or less, based on the alkali-soluble resin.

[0042] <Development Speed ​​Adjuster> The composition for forming a resist underlayer film of the present invention may contain a development speed adjuster in addition to the alkali-soluble resin, specific particles, and solvent. The development speed adjuster can be used for the purpose of adjusting the dissolution rate in a photoresist developer. Examples of the development speed adjuster include compounds containing a phenolic hydroxyl group or a carboxyl group.

[0043] For example, compounds having an aromatic ring substituted with a phenolic hydroxyl group or a carboxyl group are preferred. Examples include 1-naphthoic acid, 2-naphthoic acid, 1-naphthol, 2-naphthol, 1-aminonaphthalene, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 3,7-dihydroxy-2-naphthoic acid, 6-bromo-2-hydroxynaphthalene, 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic ...2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid, 2-naphthalenedicarboxylic acid ,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 6-hydroxy-1-naphthoic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy- 2-Naphthoic acid, 6-hydroxy-2-naphthoic acid, 1-bromo-2-hydroxy-3-naphthoic acid, 1-bromo-4-hydroxy-3-naphthoic acid, 1,6-dibromo-2-hydroxy-3-naphthoic acid, 3-hydroxy-7-methoxy-2-naphthoic acid, 1-amino-2-naphthol, 1,5-dimercaptonaphthalene, 1,4,5,8-naphthalenetetracarboxylic acid, 3,5-dihydroxy-2-naphthoic acid, 1,4-dihydroxy-2-naphthoic acid, 2-ethoxy-1-naphthoic acid, 2,6-dichloro-1 -naphthol, 2-hydroxy-3-naphthalenecarboxylic acid methyl ester, 6-hydroxy-2-naphthalenecarboxylic acid methyl ester, 3-hydroxy-7-methoxy-2-naphthalenecarboxylic acid methyl ester, 3,7-dihydroxy-2-naphthalenecarboxylic acid methyl ester, 2,4-dibromo-1-naphthol, 1-bromo-2-naphthol, 2-naphthalenethiol, 4-methoxy-1-naphthol, 6-acetoxy-2-naphthoic acid, 1,6-dibromo-1-naphthol, 2,6-dibromo-1,5-dihydroxynaphthalene, 1-acetyl-2-naphthol, 9-anthracenecarboxylic acid, 1,4,9,10-tetrahydroxyanthracene, and 1,8,9-trihydroxyanthracene, benzoic acid, 4-methylbenzoic acid, o-phthalic acid, m-phthalic acid, p-phthalic acid, 2-methoxybenzoic acid, isophthalic acid, terephthalic acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid Acid, 2-acetoxybenzoic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, trimesic acid, 1,4-benzenedicarboxylic acid, 2,3-dimethoxybenzoic acid, 2,4-dimethoxybenzoic acid, 2,5-dimethoxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 4-acetylbenzoic acid, pyrrole Examples of the hydroxybenzoic acid include butyl hydroxybenzoic acid, ...

[0044] These compounds can also be used by reacting them with a polymer or a compound having one or more reactive groups. For example, in the case of a compound having a carboxy group or a phenolic hydroxyl group, compounds obtained by reacting with an epoxy compound such as tris(2,3-epoxypropyl)isocyanurate, 1,4-butanediol diglycidyl ether, 1,2-epoxy-4-(epoxyethyl)cyclohexane, glycerol triglycidyl ether, diethylene glycol diglycidyl ether, 2,6-diglycidylphenyl glycidyl ether, 1,1,3-tris(p-(2,3-epoxypropoxy)phenyl)propane, 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 4,4'-methylenebis(N,N-diglycidylaniline), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, trimethylolethane triglycidyl ether, bisphenol-A-diglycidyl ether, and pentaerythritol polyglycidyl ether, or a polymer containing a structure having an epoxy group such as glycidyl methacrylate, can be used. Examples of such development speed adjusters include compounds represented by the following formula (45): In formula (45), Ar is a benzene ring, a naphthalene ring, or an anthracene ring substituted with one or more hydroxyl groups and / or carboxy groups, and may be substituted with a group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, a thiol group, a thioalkyl group having 1 to 5 carbon atoms, a phenoxy group, an acetyl group, an alkoxycarbonyl group having 1 to 5 carbon atoms, and a vinyl group.

[0045]

[0046] Examples of the development speed adjuster include a combination of the above-mentioned epoxy compounds such as tris(2,3-epoxypropyl)isocyanurate and 1,4-butanediol diglycidyl ether, and 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 3,7-dihydroxy-2-naphthoic acid, 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 6-hydroxy- Preferred are compounds obtainable by reacting 1-naphthoic acid, 3-hydroxy-2-naphthoic acid, 1-bromo-2-hydroxy-3-naphthoic acid, 1-bromo-4-hydroxy-3-naphthoic acid, 1,6-dibromo-2-hydroxy-3-naphthoic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 3,5-dihydroxy-2-naphthoic acid, and 1,4-dihydroxy-2-naphthoic acid with an aromatic compound having two or more carboxy groups or phenolic hydroxyl groups, such as terephthalic acid, isophthalic acid, p-hydroxybenzoic acid, m-hydroxybenzoic acid, o-hydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, and gallic acid.

[0047] The content of the development speed adjuster is, for example, 50 parts by mass or less, preferably 40 parts by mass or less, and more preferably 30 parts by mass or less, per 100 parts by mass of the alkali-soluble resin.

[0048] <Dispersant> The composition for forming a resist underlayer film of the present invention may contain a dispersant (also referred to as a “pigment dispersant.”) The dispersant is used, for example, to stably disperse specific particles.

[0049] Examples of dispersants include cationic, anionic, nonionic, amphoteric, polyester, and polyamine surfactants.

[0050] The dispersant may be a commercially available product. Examples of commercially available products include the following dispersants: Trade names of BYK Chemie: DISPER BYK-160, DISPER BYK-161, DISPER BYK-162, DISPER BYK-163, DISPER BYK-164, DISPER BYK-166, DISPER BYK-171, DISPER BYK-182, DISPER BYK-184, DISPER BYK-2000, DISPER BYK-2001, DISPER BYK-2070, and DISPER BYK-2150. BASF trade names: EFKA-44, EFKA-46, EFKA-47, EFKA-48, EFKA-4010, EFKA-4050, EFKA-4055, EFKA-4020, EFKA-4015, EFKA-4060, EFKA-4300, EFKA-4330, EFKA-4400, EFKA-4406, EFKA-4510, EFKA-4800 Lubrizol trade names: SOLSPERS-24000, SOLSPERS-32550, SOLSPERS-38500, SOLSPERS-76500, NBZ-4204 / 10 Kawaken Fine Chemicals' trade names: HINOACT T-6000, HINOACT T-7000, HINOACT T-8000 Ajinomoto Co., Inc.'s trade names: AJISPUR PB-821, AJISPUR PB-822, AJISPUR PB-823 Kyoeisha Chemical Co., Ltd.'s trade names: FLORENE DOPA-17HF, FLORENE DOPA-15BHF, FLORENE DOPA-33, FLORENE DOPA-44

[0051] The content of the dispersant is not particularly limited.

[0052] The resist underlayer film formed using the resist underlayer film-forming composition of the present invention is preferably a non-photosensitive film. For example, when a photosensitive film is used as the resist underlayer film, a certain amount of exposure is required to make the photosensitive film developable. However, since the resist film of the present invention is a light-absorbing resist film, the resist material forming the light-absorbing resist film contains a light absorber (e.g., a colorant). When attempting to expose the light-absorbing resist film, the light absorber interferes with the exposure, and the light transmittance decreases toward the lower end of the light-absorbing resist film layer. Therefore, when a photosensitive resist underlayer film is used, the resist underlayer film will be exposed to weak light that passes through the light-absorbing resist film. In such cases, the exposure amount may be insufficient, and the exposed photosensitive film may not exhibit its inherent function (e.g., developability). Therefore, regardless of whether the resist underlayer film is photosensitive or not, it is preferable to control the solubility of the light-absorbing resist film in a developer by setting the baking temperature, and form a pattern of the light-absorbing resist film and a pattern of the resist underlayer film. Therefore, it is preferable to use a non-photosensitive resist underlayer film rather than a photosensitive one.

[0053] <Preparation of Resist Underlayer Film> The resist underlayer film of the present invention is a cured product of the composition for forming a resist underlayer film described above. The resist underlayer film can be produced, for example, by applying the composition for forming a resist underlayer film described above onto a substrate and baking it.

[0054] The resist underlayer film is, for example, a white resist underlayer film. The white resist underlayer film is formed, for example, from a composition for forming a resist underlayer film containing a white pigment as a specific particle. Here, the "white" color in the white resist film refers to, for example, a color having a lightness of 8.0 or more and a saturation of 2.0 or less in the Munsell color system (JIS Z 8721).

[0055] (Laminate) The laminate of the present invention comprises a substrate, the resist underlayer film of the present invention, and a light-absorbing resist film. The substrate and the light-absorbing resist film will be described in detail below.

[0056] In preparing the laminate, the resist underlayer film preferably has a solvent resistance developing temperature set lower than the developer insolubilization temperature. That is, for example, as shown in FIG. 1, the resist underlayer film preferably exhibits a solvent resistance developing temperature (see symbol a2 in FIG. 1) lower than the developer insolubilization temperature (see symbol b2 in FIG. 1). The baking conditions for forming the resist underlayer film will be described in detail below. The laminate of the present invention may be subjected to the (laminar pattern forming method) described below to prepare a laminate in which the resist underlayer film and the light-absorbing resist film are patterned. The self-luminous display element of the present invention can be provided by using such a patterned laminate. The self-luminous display element of the present invention will be described in detail below.

[0057] (Method for forming a pattern on a laminate) The method for forming a pattern on a laminate of the present invention comprises at least the following steps: - a step of forming a resist underlayer film on a substrate using the composition for forming a resist underlayer film of the present invention - a step of forming a light-absorbing resist film on the resist underlayer film, and - a step of exposing the light-absorbing resist film to light and developing the desired portion of the light-absorbing resist film and the resist underlayer film formed under the desired portion of the light-absorbing resist film, thereby obtaining a pattern on the laminate The method for forming a pattern on a laminate may further comprise a step of thermally curing the patterned laminate by baking.

[0058] <Substrate> Examples of the substrate include glass substrates, quartz substrates, glass substrates coated with metals such as aluminum, molybdenum, and chromium, polysilicon, ITO, IZO, SiN, and SiO ２ Examples of the organic film include glass substrates on which an inorganic film such as a polyimide film, a polyethylene terephthalate film, a polycarbonate film, and a cycloolefin polymer film are formed, and semiconductor substrates such as silicon wafers, gallium arsenide, and gallium nitride. Examples of the organic film include, but are not limited to, films obtained from UV-curable resins such as color filters, overcoats, and planarizing films.

[0059] <Step of Forming Resist Underlayer Film> In the step of forming the resist underlayer film, for example, a resist underlayer film-forming composition is applied and baked to form a resist underlayer film. Examples of application methods include suitable coating methods such as a spinner or a slit coater. Baking is performed using a heating means such as a hot plate, a hot air circulation oven, or a far-infrared heating furnace. Baking performed when forming the resist underlayer film is preferably performed under temperature conditions between the "solvent resistance temperature" (see symbol a2 in FIG. 1 ) of the resist underlayer film in relation to the solvent contained in the resist material used to form the light-absorbing resist film and the "developer insolubilization temperature" (see symbol b2 in FIG. 1 ) of the resist underlayer film in an alkaline developer for the light-absorbing resist film. In other words, the resist underlayer film is preferably formed by baking a coating film made of the resist underlayer film-forming composition at a desired temperature within the temperature range indicated by symbol T in FIG. 1 . For example, if the baking temperature is higher than b2, the resist underlayer film will not dissolve in the developer; therefore, the baking temperature must be lower than b2. On the other hand, if the baking temperature is not set to a2 or higher, the photo-absorbent resist material will dissolve in the solvent, resulting in mixing with the resist material. Therefore, it is recommended to bake at a temperature in the range of a2 or higher but lower than b2, which exhibits a desirable development dissolution rate.

[0060] FIG. 2 is a schematic diagram showing the relationship between baking temperature and dissolution of a resist underlayer film in a developer. In FIG. 2(1), a resist underlayer film 2 is formed on a substrate 1. By baking a coating film of a resist underlayer film-forming composition, a resist underlayer film that is resistant to the solvent contained in the light-absorbing resist material is formed. In FIG. 2(2), a light-absorbing resist film 3 is formed on the resist underlayer film 2. In FIG. 2(2), irradiation from above a mask 4 is performed to develop the light-absorbing resist film 3 and the resist underlayer film 2 formed below the light-absorbing resist film 3. For example, when baked at a desirable baking temperature, the resist underlayer film dissolves at a good developer dissolution rate, and as shown in FIG. 2(4), portions of the resist underlayer film 2 corresponding only to portions without the light-absorbing resist film 3 are dissolved, forming a good resist pattern. On the other hand, if the resist underlayer film is baked at a temperature higher than the desired baking temperature, the resist underlayer film becomes less soluble in the developer. As a result, as shown in FIG. 2(3), the resist underlayer film 2 formed under the light-absorbing resist film 3 may not dissolve beyond the portion corresponding to the portion where the light-absorbing resist film 3 is absent (residual film, residue, etc.). In this case, a resist pattern with a good shape cannot be obtained. On the other hand, if the resist underlayer film is baked at a temperature lower than the desired baking temperature, the resist underlayer film becomes more soluble in the developer. As shown in FIG. 2(5), the resist underlayer film 2 formed under the light-absorbing resist film 3 may dissolve beyond the portion corresponding to the portion where the light-absorbing resist film 3 is absent. In this case, a resist pattern with a good shape cannot be obtained. In this way, a coating film formed from the composition for forming a resist underlayer film of the present invention can be baked under suitable temperature conditions such that the dissolution rate of the resist underlayer film in the developer is the desired rate, thereby forming a pattern with a good shape. The baking conditions are appropriately selected from, for example, a baking temperature of 120° C. to 250° C. and a baking time of 0.5 to 120 minutes, preferably a baking temperature of 130° C. to 200° C. and a baking time of 1 to 60 minutes.

[0061] The film thickness of the resist underlayer film is, for example, 0.1 μm to 50 μm, 0.2 μm to 30 μm, or 0.5 μm to 20 μm.

[0062] <Step of Forming Light-Absorbing Resist Film> A light-absorbing resist film is formed on the resist underlayer film. The film thickness of the light-absorbing resist film is, for example, 30 μm or less, 10 μm or less, or 5 μm or less.

[0063] The ratio of the thickness of the light-absorbing resist film to the thickness of the resist underlayer film (light-absorbing resist film / resist underlayer film) is not particularly limited, but is, for example, 0.005 to 10, preferably 0.01 to 5, and more preferably 0.02 to 2.

[0064] The light-absorbing resist film formed on the resist underlayer film by a known method (for example, coating and baking a light-absorbing resist material) is not particularly limited as long as it responds to light or electron beams (EB) used for irradiation. Either a negative photoresist or a positive photoresist can be used.

[0065] <<Light-Absorbing Resist Film>> The light-absorbing resist film of the present invention is formed using a light-absorbing resist material. The light-absorbing resist material refers to a material in which a light absorber is contained in a commonly known resist material. The light absorber is not particularly limited, and for example, organic or inorganic pigments can be used alone or in combination. A dye can also be added within a range that does not reduce heat resistance. Examples of the light-absorbing agent include black materials. Examples of black materials include black inorganic materials and black organic materials. Examples of black inorganic materials include carbon black, zirconium nitride, zirconium oxide, and titanium black. Examples of black organic materials include perylene black, lactam black, aniline black, anthraquinone black, and azo-based black pigments. A preferred embodiment of the light-absorbing resist film of the present invention is a light-absorbing resist film formed using a pigment-dispersed resist material. Examples of pigment-dispersed resist materials include black pigment-dispersed resist materials. The light-absorbing resist film is, for example, a black resist film. The "black" color of the black resist film refers to a color having a brightness of 2.0 or less and a chroma of 2.0 or less in the Munsell color system (JIS Z 8721).

[0066] Any light absorber that can be normally contained in a resist material can be used without any particular restrictions. A preferred embodiment of the resist material will be described below. In this specification, resists that respond to electron beams (EB) are also referred to as photoresists. Examples of photoresists include positive photoresists composed of an alkali-soluble resin such as a phenol novolac resin, a cresol novolac resin, an acrylic acid copolymer, a methacrylic acid copolymer, a hydroxystyrene copolymer, a hydroxyphenylacrylamide copolymer, a hydroxyphenylmethacrylamide copolymer, or a hydroxyphenylmaleimide copolymer and a 1,2-naphthoquinone diazide sulfonic acid ester; chemically amplified positive photoresists composed of a binder having a group that is decomposed by acid to increase the alkali dissolution rate and a photoacid generator; and photoresists that are decomposed by acid to increase the alkali dissolution rate of the photoresist. Examples of such photoresists include chemically amplified positive photoresists that consist of a low molecular weight compound that increases the dissolution rate, an alkali-soluble binder, and a photoacid generator; chemically amplified positive photoresists that consist of a binder having a group that decomposes in acid to increase the alkali dissolution rate, a low molecular weight compound that decomposes in acid to increase the alkali dissolution rate of the photoresist, and a photoacid generator; resists containing metal elements; negative photoresists that consist of an alkali-soluble resin, a polyunsaturated group-containing monomer, and a photoradical initiator; and negative photoresists that consist of an alkali-soluble resin, a polyfunctional cationically polymerizable monomer, and a photocationic initiator.

[0067] <Step of Obtaining a Pattern of the Laminate> The step of obtaining a pattern of the laminate is carried out by exposing the light-absorbing resist film to light, and developing the light-absorbing resist film in the desired portion and the resist underlayer film formed under the light-absorbing resist film in the desired portion.

[0068] The light used for exposure is not particularly limited, and examples thereof include g-line, h-line, i-line, KrF excimer laser, and ArF excimer laser. The light used for exposure may be laser or non-laser. Non-laser exposure is carried out using, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, or a metal halide lamp. The irradiation energy used for exposure is not particularly limited.

[0069] For example, an alkaline developer is used for development. The development temperature can be, for example, 5°C to 50°C. The development time can be, for example, 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of alkalis such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-butylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole and piperidine). Furthermore, the aqueous solutions of the alkalis can be used by adding an appropriate amount of alcohols (e.g., isopropyl alcohol) or a nonionic surfactant. Among these, preferred developers are aqueous solutions of potassium hydroxide and quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants and the like can also be added to these developers.

[0070] For example, when the light-absorbing resist film is a positive resist film, the light-absorbing resist film in the exposed portion is dissolved by a developer upon exposure, while the light-absorbing resist film in the unexposed portion remains. In this case, during development, in addition to the light-absorbing resist film in the exposed portion, the resist underlayer film formed under the light-absorbing resist film in the exposed portion is also dissolved by the developer. That is, the resist underlayer film corresponding to the exposed portion from which the light-absorbing resist film has disappeared due to development is also removed by development. By removing the resist underlayer film, the residue of the light-absorbing resist film after development is also removed. In this way, the light-absorbing resist film in the desired portion and the resist underlayer film formed under the light-absorbing resist film in the desired portion are removed by development, so that no residue of the light-absorbing resist film is generated, and the patterned light-absorbing resist film is not peeled off, and a good light-absorbing resist pattern and a pattern of the resist underlayer film thereunder are formed. Alternatively, when the light-absorbing resist film is, for example, a negative resist film, the light-absorbing resist film in the unexposed portion is dissolved by the developer upon exposure, while the light-absorbing resist film in the exposed portion remains. In this case, during development, in addition to the light-absorbing resist film in the unexposed portion, the resist underlayer film formed under the light-absorbing resist film in the unexposed portion is also dissolved by the developer. That is, the resist underlayer film corresponding to the unexposed portion where the light-absorbing resist film has disappeared due to development is also removed by development. By removing the resist underlayer film, the residue of the light-absorbing resist film after development is also removed. In this way, the light-absorbing resist film in the desired portion and the resist underlayer film formed under the light-absorbing resist film in the desired portion are removed by development, so that no residue of the light-absorbing resist film is generated, and the patterned light-absorbing resist film is not peeled off, and a good light-absorbing resist pattern and a pattern of the resist underlayer film thereunder are formed.

[0071] <Thermal Curing Step> The laminate of the patterned light-absorbing resist obtained by development and the underlying resist underlayer film is thermally cured to improve film properties. The heating temperature during thermal curing is not particularly limited, and may be, for example, 150°C to 300°C. The heating time during thermal curing is not particularly limited, and may be, for example, 1 minute to 5 hours.

[0072] The pattern of the light-absorbing resist and the pattern of the resist underlayer film thereunder are, for example, fine structures formed by superimposing fine structures of two different colors, and such fine structures are used, for example, as partition walls of a display element.

[0073] (Self-luminous display element) The self-luminous display element of the present invention has a laminate formed by the above-mentioned method for forming a pattern of a laminate according to the present invention. That is, the self-luminous display element of the present invention has a laminate in which the above-mentioned pattern formation is applied to the laminate of the present invention described in the above (Laminate) section, and a resist underlayer film and a light-absorbing resist film are patterned. Here, examples of the self-luminous display element include light-emitting diodes (OLEDs) and micro LEDs that use organic electroluminescence.

[0074] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. In the examples, the apparatus and conditions used for sample preparation and analysis of physical properties are as follows:

[0075] <Abbreviations of compounds> ・CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride ・APAB: 4-aminophenyl 4-aminobenzoate ・NMP: N-methyl-2-pyrrolidone ・HEMA: 2-hydroxyethyl methacrylate ・NHPMA: N-(4-hydroxyphenyl)methacrylamide ・CHMI: N-cyclohexylmaleimide ・AIBN: α,α'-azobisisobutyronitrile ・PGME: Propylene glycol monomethyl ether ・PGMEA: Propylene glycol monomethyl ether acetate ・QD: A compound synthesized by condensation reaction of 1 mol of α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene with 2 mol of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride ・GT-401: Butanetetracarboxylic acid Tetra(3,4-epoxycyclohexylmethyl)-modified ε-caprolactone [Epolead GT-401, manufactured by Daicel Corporation] R-40: Megafac (registered trademark) R-40 (manufactured by DIC Corporation) TMAH: tetramethylammonium hydroxide

[0076] (1) Ultraviolet irradiation device: PLA-600FA manufactured by Canon Inc. (2) Developing device: AD-1200 manufactured by Takizawa Sangyo Co., Ltd. (3) Gel permeation chromatography (GPC) <GPC (1): for polyamic acid> Device: manufactured by JASCO Corporation Column: Shodex (registered trademark) GPC KD-803 and GPC KD-805 manufactured by Resonaq Co., Ltd. Column temperature: 50°C Eluent: dimethylformamide / LiBr.H ２ O (30 mM) / H ３ P.O. ４(30 mM) / tetrahydrofuran (1%) Flow rate: 1.0 mL / min Weight average molecular weight (hereinafter referred to as Mw): Standard polyethylene oxide equivalent value <GPC (2): for acrylic polymer> Apparatus: manufactured by Shimadzu Corporation Column: Shodex (registered trademark) GPC K-803L, GPC K-804L manufactured by Resonac Corporation Column temperature: 40°C Eluent: tetrahydrofuran Mw: Polystyrene equivalent value (4) Residue evaluation Apparatus: Optical microscope MX61A manufactured by Olympus Corporation Apparatus: Scanning electron microscope S-4800 manufactured by Hitachi High-Technologies Corporation

[0077] Synthesis Example 1 Synthesis of Polyamic Acid A1 (Polyamic Acid) 8.07 g (35.3 mmol) of APAB was dissolved in 114.75 g of NMP, and then cooled to 5 to 15°C in an ice bath under a nitrogen atmosphere. 6.93 g (35.3 mmol) of CBDA and 20.25 g of NMP were added to the resulting solution, and the temperature was returned to room temperature and reacted for 24 hours. The resulting polyamic acid A1 had an Mw of 31,200 and an Mw / Mn ratio of 1.8.

[0078] Example 1 Preparation of a composition for forming a resist underlayer film A solution containing 17.54 g of polyamic acid A1 (polyamic acid) was added with TiO ２ 1.78 g of the cyclopentanone dispersion (average particle size: 130 nm) and 8.04 g of NMP were added and stirred at room temperature for 2 hours to prepare a composition for forming a resist underlayer film [1].

[0079] Synthesis Example 2 Synthesis of Acrylic Polymer B1 3.00 g of NHPMA, 0.98 g of HEMA, 2.34 g of CHMI, and 0.12 g of AIBN were dissolved in 24.20 g of PGME and reacted at 90° C. for 20 hours to obtain an acrylic polymer solution (B1) (solid content concentration: 21% by mass). The obtained acrylic polymer had an Mn of 5,400 and an Mw of 8,900.

[0080] Synthesis Example 3 Synthesis of Acrylic Polymer B2 3.00 g of NHPMA, 1.11 g of HEMA, 3.04 g of CHMI, and 0.14 g of AIBN were dissolved in 27.30 g of PGME, and the mixture was allowed to react at 90° C. for 20 hours to obtain an acrylic polymer solution (B2) (solids concentration: 21% by mass). The resulting acrylic polymer had an Mn of 5,000 and an Mw of 8,900.

[0081] Preparation Example 1 Preparation of a Light-Absorbing Resist Film-Forming Composition 5.50 g of acrylic polymer solution (B1), 2.31 g of acrylic polymer solution (B2), 0.50 g of QD, 0.50 g of GT-401, and 0.03 g of a PGME solution of R-40 (solid content concentration 5.0% by mass) were dissolved in 3.49 g of PGMEA and 2.39 g of PGME, and the mixture was stirred at room temperature for 30 minutes. 5.25 g of a solution (solid content concentration 20.6% by mass) in which an organic black pigment was dispersed in PGMEA was added to the resulting solution, and the mixture was stirred at room temperature for 30 minutes to prepare a light-absorbing resist film-forming composition [2] (solid content concentration 17.5% by mass). This composition is a positive resist composition.

[0082] (Evaluation 1) <Evaluation of Pattern Shape of Laminate Composed of Resist Underlayer Film and Light-Absorbing Resist Film> A resist underlayer film-forming composition [1] was applied to a glass substrate with an ITO film using a spinner, and then dried on a hot plate at 90°C for 3 minutes. This was then baked on a hot plate at 190°C for 3 minutes to form a resist underlayer film with a thickness of 3 μm. A light-absorbing resist film-forming composition [2] was applied to the obtained resist underlayer film using a spinner, and then dried on a hot plate at 100°C for 3 minutes to laminate a light-absorbing resist film with a thickness of 1 μm. A mixed ultraviolet ray of g, h, and i was irradiated at 120 mJ / cm on the obtained laminate film through a mask set so as to form a 50 μm line / space pattern. ２ The film was irradiated with light. Thereafter, puddle development was performed with a 2.38% TMAH aqueous solution at 23°C for 50 seconds, followed by rinsing with running ultrapure water for 30 seconds. The laminate with the line / space pattern formed thereon was observed using an optical microscope and a scanning electron microscope S-4800 manufactured by Hitachi High-Technologies Corporation. An SEM image is shown in Figure 3.

[0083] As shown in the SEM image of FIG. 3 , in the obtained laminate, the exposed areas of the light-absorbing resist film and the resist underlayer film were dissolved, while the unexposed areas were not dissolved, forming a line pattern, and no residue or remaining film was observed in the openings (space areas).

[0084] 1 Substrate 2 Resist underlayer film 3 Light-absorbing resist film 4 Mask

Claims

1. A composition for forming a resist underlayer film for forming a resist underlayer film disposed between a substrate and a light-absorbing resist film, the composition for forming a resist underlayer film comprising an alkali-soluble resin, particles having at least one of light reflectivity and light scattering property, and a solvent, and the resist underlayer film formed by baking the composition for forming a resist underlayer film exhibits solvent resistance to a solvent contained in a resist material for forming the light-absorbing resist film and exhibits solubility in an alkaline developer for the light-absorbing resist film.

2. The composition for forming a resist underlayer film according to claim 1, wherein the alkali-soluble resin is a polyamic acid.

3. The composition for forming a resist underlayer film according to claim 1, which contains a crosslinking agent.

4. The composition for forming a resist underlayer film according to claim 3, wherein the crosslinking agent is an epoxy compound.

5. The composition for forming a resist underlayer film according to claim 1, which contains a development speed adjuster.

6. The composition for forming a resist underlayer film according to claim 5, wherein the development speed adjuster is a compound containing a phenolic hydroxyl group or a carboxyl group.

7. The composition for forming a resist underlayer film according to claim 1, wherein the particles are metal particles, white organic pigments, or white inorganic pigments.

8. The composition for forming a resist underlayer film according to claim 7, wherein the particles are a white inorganic pigment selected from the group consisting of titanium dioxide, zirconium oxide, zinc oxide, calcium carbonate, and barium sulfate.

9. The composition for forming a resist underlayer film according to claim 1, wherein the light-absorbing resist film is a black resist film.

10. A resist underlayer film, which is a cured film of the composition for forming a resist underlayer film according to any one of claims 1 to 9.

11. The resist underlayer film according to claim 10, which is non-photosensitive.

12. A laminate comprising a substrate, the resist underlayer film according to claim 10, and a light-absorbing resist film.

13. The laminate according to claim 12, wherein the temperature at which the resist underlayer film develops solvent resistance to a solvent contained in a resist material for forming the light-absorbing resist film is set lower than the temperature at which the resist underlayer film becomes insolubilized in an alkaline developer of the light-absorbing resist film.

14. A method for forming a pattern of a laminate, comprising: a step of forming a resist underlayer film on a substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 9; a step of forming a light-absorbing resist film on the resist underlayer film; and a step of exposing the light-absorbing resist film to light, and developing the light-absorbing resist film in a desired portion and the resist underlayer film formed under the light-absorbing resist film in the desired portion, thereby obtaining a pattern of the laminate.

15. The method for forming a pattern on a laminate according to claim 14, wherein the baking performed when forming the resist underlayer film is performed under temperature conditions between a temperature at which the resist underlayer film exhibits solvent resistance to a solvent contained in a resist material for forming the light-absorbing resist film and a temperature at which the resist underlayer film becomes insolubilized in an alkaline developer for the light-absorbing resist film.

16. The method for forming a laminate pattern according to claim 14, wherein the light-absorbing resist film is formed using a black pigment dispersed resist material.

17. A laminate formed by the method for forming a laminate pattern according to claim 14.

18. A self-luminous display element comprising the laminate according to claim 17.

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