Method for manufacturing light-emitting elements

Abstract

Provided is a photoresist that can form a photoresist layer having both developability and polar solvent resistance while having excellent peel removability as a positive photoresist layer. This composition for forming a photoresist comprises a water-soluble resin, a positive photosensitive agent, and a solvent, the water-soluble resin comprising a copolymer includuing a vinyl alcohol monomer unit.

Description

[Technical Field]

[0001] This disclosure , This invention relates to a method for manufacturing an optical element. More specifically, to a composition containing a water-soluble resin copolymer and a diazoquinone compound. things This relates to a method for manufacturing the light-emitting element used. [Background technology]

[0002] Patent Document 1 describes a positive-type photosensitive composition for creating a positive-type image-forming material, which is used by dissolving it in an organic solvent, and contains a water-insoluble organic solvent-soluble o-diazonaphthoquinone compound as a positive-type photosensitive agent, a polyvinylpyrrolidone compound as a binder, and stannic halide as a stabilizer. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 05-011405 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in the case of positive-type photosensitive compositions such as those described in Patent Document 1, the unexposed areas after patterning are easily dissolved in polar solvents in the manufacturing of coated and laminated devices such as organic ELs, which presents problems with the developability of the pattern. In contrast, negative-type photosensitive compositions, for example, have higher resistance to polar solvents in the exposed areas than positive-type photosensitive compositions, but they have the problem of being difficult to peel off and remove after patterning.

[0005] Therefore, there is a need for a positive-type photosensitive composition that can form a photoresist layer with high resistance to polar solvents without impairing peelability.

[0006] One aspect of this disclosure has been made in view of the above-mentioned problems and aims to provide a composition and related technologies that can be used as a photoresist that is suitable for lift-off patterning of functional layer materials in polar solvent systems, possessing high exfoliation properties as a positive-type photoresist, while also having developability and resistance to polar solvents. [Means for solving the problem]

[0007] To solve the above problems, a composition according to one aspect of the present disclosure comprises a water-soluble resin, a positive-type photosensitive agent, and a solvent, wherein the water-soluble resin comprises vinyl alcohol monomer units and water-soluble monomer units.

[0008] Furthermore, a manufacturing method for manufacturing a light-emitting element according to one aspect of the present disclosure includes the steps of: coating the composition onto a substrate; exposing the coated composition to light; washing the exposed composition with a developer to develop a pattern of the composition onto the substrate; forming a light-emitting layer on the substrate on which the pattern has been developed; and peeling off and developing the remaining composition on the substrate on which the light-emitting layer has been formed using a solvent. [Effects of the Invention]

[0009] According to one aspect of this disclosure, a composition can be provided that can form a photoresist layer that has high peelability as a positive-type photoresist layer, while also possessing developability and resistance to polar solvents. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing an outline of the steps included in the method for manufacturing a light-emitting element according to Embodiment 2 of this disclosure. [Figure 2] This is a cross-sectional view showing a schematic of the process for forming the photoresist layer 50, which is included in the method for manufacturing a light-emitting element according to Embodiment 2 of this disclosure. [Figure 3] This is a schematic cross-sectional view showing the process of exposing the photoresist layer 50 in the method for manufacturing a light-emitting element according to Embodiment 2 of this disclosure. [Figure 4] A cross-sectional view showing an overview of a process of developing a pattern in an exposed photoresist layer 50 included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 5] A cross-sectional view showing an overview of a process of forming a first light-emitting layer 70R included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 6] A cross-sectional view showing an overview of a process of lift-off developing a first light-emitting layer 70R included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 7] A cross-sectional view showing an overview of a process of forming a photoresist layer 51 (a process of forming a second composition) included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 8] A cross-sectional view showing an overview of a process of exposing a photoresist layer 51 (a process of second exposure) included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 9] A cross-sectional view showing an overview of a process of developing a pattern in a photoresist layer 51 (a process of second development) included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 10] A cross-sectional view showing an overview of a process of forming a second light-emitting layer 70B (a process of forming a second light-emitting layer) included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 11] A cross-sectional view showing an overview of a process of lift-off developing a second light-emitting layer 70B (a process of second lift-off development) included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 12] A cross-sectional view showing an overview of a process of forming a photoresist layer 52 (a process of forming a third composition) included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 13] A cross-sectional view showing an overview of a process of exposing a photoresist layer 52 (a process of third exposure) included in the method for manufacturing a light-emitting element according to Embodiment 2 of the present disclosure. [Figure 14]This is a schematic cross-sectional view showing the process of developing a pattern on the photoresist layer 52 (the third development step) in the method for manufacturing a light-emitting element according to Embodiment 2 of this disclosure. [Figure 15] This is a schematic cross-sectional view showing the step of forming the third light-emitting layer 70G (the step of forming the third light-emitting layer) in the method for manufacturing a light-emitting element according to Embodiment 2 of this disclosure. [Figure 16] This is a schematic cross-sectional view showing the step of peeling and developing the third light-emitting layer 70G (the third peeling and developing step) in the method for manufacturing a light-emitting element according to Embodiment 2 of this disclosure. [Figure 17] This is a schematic cross-sectional view of a display device 200 comprising a plurality of light-emitting elements 100R, 100B, and 100G manufactured by the method for manufacturing light-emitting elements according to Embodiment 2 of this disclosure. [Modes for carrying out the invention]

[0011] [Embodiment 1: Positive-type photosensitive composition] One embodiment of this disclosure will be described in detail below.

[0012] A positive-type photosensitive composition (composition) according to one embodiment of the present disclosure comprises a water-soluble resin, a diazoquinone compound, and a solvent, and may also contain other materials.

[0013] [Water-soluble resin] The water-soluble resin is a thermoplastic resin that is water-soluble, and is a water-soluble resin that dissolves in pure water and alkaline aqueous solutions, and may contain copolymers containing vinyl alcohol monomer units. The water-soluble resin is a copolymer containing two or more monomer units, namely vinyl alcohol monomer units and other monomer units, wherein the vinyl alcohol monomer units and other monomer units are monomer units derived from water-soluble monomers.

[0014] The content of vinyl alcohol monomer units in the water-soluble resin is preferably 35 to 90 mol% or more. By having a vinyl alcohol monomer unit content within the range of 35 to 90 mol% or more, the developability and polar solvent resistance of the photoresist layer formed from the positive-type photosensitive composition can be controlled. The water-soluble resin may be any copolymer containing vinyl alcohol monomer units, and the monomer units other than vinyl alcohol monomer units contained in the copolymer may be, for example, monomer units constituting the second polymer unit described later.

[0015] Water-soluble resins may have their water solubility adjusted by polymerizing vinyl alcohol monomer units, specifically by substituting some of the hydrogen atoms in the hydroxyl groups of the vinyl alcohol polymer units with hydrophobic groups. Examples of hydrophobic groups include epoxy groups and (meth)acryloyl groups.

[0016] The water-soluble resin may be a copolymer of vinyl alcohol monomer units and other water-soluble monomer units. Preferably, it is a block copolymer or graft copolymer containing vinyl alcohol polymer units formed by the polymerization of vinyl alcohol monomer units and polymer units derived from water-soluble monomer units other than vinyl alcohol polymer units, and more preferably a graft copolymer. By making the water-soluble resin a copolymer of two or more monomer units, such as a block copolymer or graft copolymer containing vinyl alcohol polymer units and other polymer units, the film-forming properties of the water-soluble resin can be suitably controlled by the differences in water solubility of each monomer unit, thereby controlling the developability and polar solvent resistance of the photoresist layer described later. Furthermore, the photoresist layer can be given high peelability as a positive-type photoresist layer.

[0017] When the water-soluble resin is a block copolymer or a graft copolymer, the first polymer unit may be a vinyl alcohol polymer unit, and the water-soluble resin may be designed by adjusting the ratio of the vinyl alcohol polymer unit to a polymer unit having relatively different water solubility (hereinafter referred to as the second polymer unit). More specifically, for example, by setting the total molar amount of monomer units contained in the first polymer unit and the second polymer unit to 1.0 and adjusting the ratio of the molar amount of monomer units contained in the first polymer unit, the film-forming properties of the water-soluble resin can be controlled, thereby controlling the developability and polar solvent resistance of the photoresist layer described later.

[0018] The vinyl alcohol polymer unit is described as the first polymer unit contained in the water-soluble resin, and its ratio is described as the PVA (polyvinyl alcohol) ratio. The PVA ratio is preferably 0.3 to 0.9. A PVA ratio greater than 0.3 enhances the resistance of polar solvents in the unexposed areas of the photoresist layer formed by the positive-type photosensitive composition. This prevents excessive removal of the unexposed areas of the photoresist layer by the developer. Furthermore, a PVA ratio less than 0.9 prevents excessive residue of the water-soluble resin, thereby improving the developability of the exposed areas of the photoresist layer. The ratio of vinyl alcohol polymer units to the second polymer unit in the block copolymer or graft copolymer may be adjusted according to the PVA ratio value of 0.3 to 0.9.

[0019] The water solubility of the second polymer unit of a water-soluble resin can be determined as the solubility parameter (SP value) of the water-soluble resin. An approximate value of the SP value can be estimated from the SP values ​​of the monomers contained in the water-soluble resin.

[0020] Furthermore, the SP value of the second polymer unit can be divided into three terms as shown in equation (1) below. δ (solubility parameter) = (δ D 2 +δ P 2 +δH 2 ) 1 / 2 …(1) (In formula (1), δ D is the dispersion term, δ P is the polarity term, and δ H is the hydrogen bond term.) Among the parameters shown in formula (1), the polymer unit of the water-soluble resin has a polarity term δ P of 5.0 or more, which is preferable from the viewpoint of enhancing the resistance to polar solvents in the organic solvent developer in the photoresist layer and enhancing the solubility resistance to alkaline aqueous developers (which is also an example of polar solvent resistance). The polarity term δ P can be obtained, for example, from Hansen solubility parameter calculation software, and can be estimated from the polarity term δ P of the monomer constituting the water-soluble resin and the molar ratio of the monomer units contained in the water-soluble resin.)

[0021] The type of monomer unit constituting the second polymer unit in the water-soluble resin may be selected according to the water solubility of the homopolymer of each monomer unit. The water solubility of the homopolymer of each monomer unit may be estimated by referring to the SP value of the homopolymer or the SP value of the monomer. When the water-soluble resin is a block copolymer or a graft copolymer, the polymer unit with relatively low water solubility may be referred to as the first polymer unit, and the polymer unit with relatively high water solubility may be referred to as the second polymer unit. It is preferable that the difference (the difference in SP values) between the water solubility of the first polymer unit and the water solubility of the second polymer unit is large. The SP value of polyvinyl alcohol, which is the first polymer unit, is 12.6, and this SP value is referred to as the SP value of the homopolymer.)

[0022] The monomer constituting the second polymer unit may have, for example, an SP value of 9.0 or more, preferably 25.8 or more. As such a monomer, for example, (meth)acrylic acid (SP valueExamples include (meth)acrylic acid (SP value: 9.6), (meth)acrylate salts, (meth)acrylamide (SP value: 9-15), N-vinylacetamide (SP value: 10.9), and more preferably N-vinylpyrrolidone (SP value: 26.2). The SP value of the monomer constituting the second polymer unit is not limited, but may be, for example, 30.0 or less. Monomer units derived from these monomers include monomer units derived from (meth)acrylic acid, monomer units derived from (meth)acrylate salts, monomer units derived from (meth)acrylamide, and monomer units derived from N-vinylacetamide. Other monomer units include ethylene oxide units, propylene oxide units, ethyleneamine units, and propyleneamine units. The water-soluble monomer units constituting the second polymer unit may be monomer units derived from monomers having hydrophilic groups such as carboxyl groups, hydroxyl groups, amino groups, and amide groups. These monomer units may also form hydrophilic main chains, such as polyether chains like polyethylene glycol and polyamine chains like spermine and spermidine, through polymerization.

[0023] In this specification, "(meth)acrylic acid" includes both the meanings of "acrylic acid" and "methacrylic acid," and "(meth)acrylamide" includes both the meanings of "acrylamide" and "methacrylamide."

[0024] [Positive-type photosensitive material] Positive-type photosensitive materials are, for example, decomposed (also called depolymerization) by light irradiation, and protons (H + Any compound that produces an organic compound having an acidic group such as a carboxylic acid group or a sulfonic acid group with a carboxylic acid group is acceptable. For example, organic compounds having a carboxylic acid group include indenecarboxylic acid, phthalic acid, and their derivatives. Positive-type photosensitive agents are typically diazoquinone compounds. Therefore, in the following, positive-type photosensitive agents will be described using diazoquinone compounds, which are typical examples. Diazoquinone compounds include diazoquinones such as diazobensoquinone (DBQ) and diazonaphthoquinone (DNQ), and their derivatives.

[0025] By using a diazoquinone compound as a positive-type photosensitive agent, as described later, the polar solvent resistance of the photoresist layer in the unexposed areas is increased, while the polar term δ of the photoresist layer is increased. P The exfoliation properties are enhanced by solvents with a pH of 5.0 or higher. Furthermore, by including a diazoquinone compound, high exfoliation properties can be imparted to the positive-type photoresist layer.

[0026] Diazoquinone derivatives may be compounds in which a diazoquinone moiety and a residue derived from a compound having a hydroxyl group or an amino group are linked via an ester bond or an amide bond. Here, the diazoquinone moiety may have, for example, a sulfonyl group in order to form an ester bond or an amide bond. A diazoquinone compound may be a compound having an ester bond or an amide bond derived from a sulfonyl group on the diazoquinone moiety and a hydroxyl group or an amino group on the compound. Here, the residue derived from the compound having a hydroxyl group is an alcohol residue, and the residue derived from the compound having an amino group is an amine residue.

[0027] When a compound that forms an ester bond or amide bond with the diazoquinone moiety has a hydroxyl group or amino group with two or more progenitor values, the conversion rate of the hydroxyl group or amino group of the compound by the diazoquinone moiety is preferably 30 mol% or more. Furthermore, although not limited thereto, the conversion rate of the hydroxyl group or amino group of the compound by the diazoquinone moiety may be substantially 100 mol%. This allows for favorable control of the solubility of the photoresist layer in the developer before and after exposure, thereby controlling developability and resistance to polar solvents. The conversion rate of the diazoquinone moiety is defined as the conversion rate of the hydroxyl group of the compound to an ester bond, or the conversion rate of the amino group of the compound to an amide bond, and is calculated using the following formula. (Number of moles of the diazoquinone moiety) / (Number of moles of hydroxyl and amino groups in the compound before conversion to the diazoquinone moiety) × 100

[0028] Examples of diazoquinone derivatives include azoquinone sulfonic acid esters and azoquinone sulfonamides.

[0029] Examples of diazoquinone sulfonic acid esters include diazobenzoquinone compounds such as 1,2-benzoquinone diazo-4-sulfonic acid ester and 1,2-benzoquinone diazo-5-sulfonic acid ester, and diazonaphthoquinone compounds such as 1,2-naphthoquinone diazo-5-sulfonic acid ester and 1,2-naphthoquinone diazo-4-sulfonic acid ester. Diazoquinone sulfonic acid derivatives may be diazo-coupled.

[0030] Compounds used to form residues (alcohol residues) derived from compounds having hydroxyl groups in diazoquinone compounds include compounds having phenolic hydroxyl groups. Compounds having phenolic hydroxyl groups may be phenols having monovalent hydroxyl groups, such as phenol and naphthol; phenols having divalent or more hydroxyl groups, such as catechol and pyrogallol; phenols having divalent or more phenolic hydroxyl groups, such as bisphenol, trisphenol, and tetrakisphenol; or phenol resins, such as novolac-type phenolic resins. Examples of compounds having a phenolic hydroxyl group include 4,4',4”-ethyridinetrisphenol, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, α,α-bis(4-hydroxyphenyl)-4-(4-hydroxy-α,α-dimethylbenzyl)-ethylbenzene, 4,4'-(1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene)diphenol, and novolac-type cresol resins.

[0031] Furthermore, as a diazoquinone compound, diazoquinone sulfonamides include, for example, compounds formed by ester bonding of a hydroxyl group of an amino alcohol with a resin having a carboxyl group, thereby introducing a 1,2-benzoquinone diazo-4-sulfonyl group or the like to the amino group introduced into the resin, thereby forming a sulfonamide.

[0032] The positive-type photosensitive composition contains, with the total amount of the water-soluble resin and the diazoquinone compound being 100% by mass, the diazoquinone compound content is preferably 15% by mass or more, more preferably 30% by mass or more, more preferably 50% by mass or more, and 70% mass It is even more preferable that the content be % or more. Furthermore, although not limited thereto, the content of the diazoquinone compound may be 90% by mass or less.

[0033] Furthermore, the positive photosensitive agent included in the positive photosensitive composition is not limited to the diazoquinone compounds described above. The positive photosensitive agent may be, for example, at least one positive photosensitive agent selected from the group consisting of the diazoquinone compounds, polyolefin sulfones, and polyphthalaldehydes described above. The polyolefin sulfone may be any photosensitive polyolefin sulfone, for example, a photosensitive polyolefin sulfone in which a dye that generates an amine upon absorption of light is introduced into the side chain of the polyolefin sulfone via a carbon bonded to the sulfone group in the polyolefin sulfone chain. The polyphthalaldehyde may be any photosensitive polyphthalaldehyde, for example, polyphthalaldehyde (PPA) and photosensitive polyphthalaldehydes such as polyphthalaldehyde having an oxime ether terminus.

[0034] 〔solvent〕 The solvents contained in the positive-type photosensitive composition include water, alcohols such as ethanol, isopropyl alcohol (IPA), and ethylene glycol, polar solvents such as N-methylpyrrolidone (NMP) and dimethyl sulfoxide (DMSO), nitriles such as acetonitrile, ketones such as acetone and methyl ethyl ketone, and polyethylene glycol monomethyl ether acetate (PEGMEA). Two or more of these solvents may be used in combination.

[0035] [Crosslinking agent] Positive-type photosensitive compositions may contain a crosslinking agent. The crosslinking agent is a crosslinking agent that crosslinks the diazoquinone compound contained in the positive-type photosensitive composition with the acid produced when the compound is exposed to light. Examples include novolac-type phenolic resins, epoxy resins, melamine resins, unsaturated polyester resins, polyimide resins, diallyl phthalates, and urethane resins. By controlling the content of the crosslinking agent and the firing conditions when forming the photoresist layer, the degree of crosslinking can be controlled, and this control of solubility results in the acquisition of more accurate patterns. When a positive-type photosensitive composition contains a crosslinking agent, the content of the crosslinking agent should not be limited, but for example, it should be more than 0 parts by mass, with the total of the water-soluble resin and the diazoquinone compound being 100 parts by mass, preferably 100 parts by mass or less, and more preferably 50 parts by mass or less.

[0036] [Other additives] In addition, the composition for forming the photoresist layer may contain, as additives, photosensitizers such as acetophenone, chemical sensitizers, fillers, colorants, stabilizers such as antioxidants, and surfactants such as leveling agents, defoamers, and dispersants.

[0037] Examples of the surfactant include fluorine-based solvents such as hydrofluoroethers and hydrofluoroolefins, and fluorine-based surfactants having hydrophobic groups and hydrophilic groups, such as hydrofluoroether chains and hydrofluoroolefin chains.

[0038] The photoresist layer, which is a coating film formed by coating from a positive-type photosensitive composition, has a solvent SP value and a polarity term δ p The dissolution rate differs depending on the polar term δ in the unexposed areas of the photoresist layer. p The dissolution rate for 7.8) is preferably 10 nm / second or more, and more preferably 50 nm / second or more, at room temperature (23°C). Furthermore, although not limited, the dissolution rate for dimethyl sulfoxide should be 2000 nm / second or less.

[0039] The photoresist layer, which is a coating film formed from a positive-type photosensitive composition, contains ethanol (polar term δ p The dissolution rate for 4.3) should be 10 nm / second or less at room temperature (23°C), and more preferably 5 nm / second or more. Furthermore, although not limited, the dissolution rate for ethanol should be 20 nm / second or less.

[0040] The dissolution rate of dimethyl sulfoxide and ethanol in the unexposed areas of the photoresist layer can be evaluated in accordance with the "evaluation of film thickness reduction" described in the examples of this disclosure, and can be calculated from the results of the film thickness reduction evaluation.

[0041] The photoresist layer formed from the positive-type photosensitive composition has a polar term δ, as exemplified by ethanol, as described later. p However, its resistance to polar solvents with a polarity of 5.0 or lower has been improved.

[0042] [Embodiment 2: Method for manufacturing a light-emitting element] Other embodiments of this disclosure are described below.

[0043] A method for manufacturing a light-emitting element according to one embodiment of the present disclosure will be explained with reference to Figures 1 to 17. As shown in Figures 1 to 17, a method for manufacturing a light-emitting element according to one embodiment of the present disclosure includes the steps of (i) coating a positive-type photosensitive composition (composition) onto a substrate, (ii) exposing the coated composition to light, (iii) washing the exposed positive-type photosensitive composition with a developer to develop a pattern of the composition onto the substrate, (iii) forming an emissive layer on the substrate on which the pattern has been developed, and (iv) peeling and developing the remaining composition on the substrate on which the emissive layer has been formed using a solvent. This produces an emissive layer 70R on the substrate 10. Furthermore, by repeating steps (i) to (iv), light-emitting elements 100R, 100B, and 100G, each having a plurality of emissive layers 70R, 70B, and 70G on the substrate 10, are produced, and a display device 200 equipped with these plurality of light-emitting elements is produced.

[0044] As shown in Figure 1, the substrate 10 has the first electrode 20 and the first charge transport layer 30 formed in a configuration partitioned into banks 40.

[0045] The substrate 10 may be a resin substrate made of a resin material such as polyimide, or it may be a glass substrate. For example, when manufacturing a non-flexible display device, a glass substrate can be used as the substrate.

[0046] The first electrode 20 can be an anode or a cathode, and is not limited to that, but in this embodiment it is an anode.

[0047] The first charge transport layer 30 may be a hole transport layer or an electron transport layer, and is not limited to that, but in this embodiment it is a hole transport layer. The first charge transport layer 30, which is a hole transport layer, may be formed from a hole injection material or a composition containing a hole transport material, as described later.

[0048] The bank 40 can be formed beforehand, before the electrodes are formed, in order to insulate the first electrodes 20 from each other.

[0049] Figure 2 is a diagram illustrating the schematic of the process for forming the photoresist layer 50. The photoresist layer 50 is formed from a positive-type photosensitive composition according to one aspect of this disclosure.

[0050] The positive-type photosensitive composition is coated onto multiple subpixels of a light-emitting element by a dip-coating method, spin-coating method, etc., thereby providing a photoresist layer 50. The photoresist layer 50 can then be heated and dried at a temperature, for example, in the range of 80 to 150°C. The positive-type photosensitive composition is not limited to being coated onto all subpixels at once; for example, it may be coated onto each subpixel separately by an inkjet method, etc. Heating the photoresist layer 50 can promote diazo coupling of the diazoquinone compound. This increases the number of bonding sites in the photoresist layer 50, thereby improving resistance to polar solvents. Furthermore, esterification can be achieved by the reaction of the hydroxyl group of the vinyl alcohol monomer unit with the acid compound formed from the diazo compound, thereby improving resistance to polar solvents.

[0051] After heating and drying the photoresist layer 50, the photoresist layer 50 formed on the first charge transport layer 30 may be exposed using a photomask 300 having a desired pattern, as shown in Figure 3. Examples of light used to expose the photoresist layer 50 include ultraviolet light with a wavelength of approximately 150-450 nm and electron beams. This ultraviolet light may be g-line (wavelength 436 nm), h-line (wavelength 405 nm), or i-line (wavelength 365 nm) from a high-pressure mercury lamp, or it may be an excimer laser (wavelength 150-248 nm). The exposure dose is not limited, but for example, 1 mJ / cm² is used. 2 ~1000 mJ / cm 2 It is sufficient if it is within this range. This means that the surface from the photoresist layer 50 to the first charge transport layer 30 should be sufficiently exposed.

[0052] Figure 4 is a schematic diagram illustrating the process of washing the photoresist layer 50 with a developer and developing a pattern on the exposed areas of the photoresist layer 50. In the exposed areas of the photoresist layer 50, acidic compounds such as derivatives of indenecarboxylic acid are generated, thereby increasing its solubility in alkaline aqueous developer. Therefore, the desired pattern can be developed on the photoresist layer 50 by washing with alkaline aqueous developer. Here, the photoresist layer 50 remaining in the unexposed areas contains a water-soluble resin containing polymer units formed by the polymerization of vinyl alcohol monomer units, and its solvent resistance is enhanced by the numerous diazocoupling bonds in the diazoquinone compound. This prevents excessive dissolution of the photoresist layer 50 during development with alkaline aqueous developer. Furthermore, because the unexposed areas of the photoresist layer 50 have increased resistance to polar solvents, high developability that enables the creation of patterns with clear contrast can be obtained.

[0053] The photoresist layer 50 can be developed to a desired pattern by, for example, immersing it in a beaker (not shown) containing a developer. The developer may be supplied to the photoresist layer 50 by, for example, spraying it using a spray nozzle.

[0054] The developer is preferably an alkaline aqueous developer. Examples of alkaline aqueous developers include aqueous developers containing alkalis such as potassium hydroxide (KOH) and tetramethylammonium hydroxide (TMAH). Even if the SP value and polarity term of an aqueous developer such as an alkaline aqueous developer are high, it is still a water-based polar solvent, and the unexposed areas of the photoresist layer 50 have increased resistance to polar solvents in the alkaline aqueous developer.

[0055] The developed photoresist layer 50 may be heat-dried at a temperature of, for example, 50 to 150°C.

[0056] Figure 5 is a schematic diagram illustrating the process of forming an emissive layer 70R on a pattern formed on a photoresist layer 50. The emissive layer 70R can be formed by coating a composition containing an emissive material onto the patterned photoresist layer 50. The emissive layer 70R' is provided in the non-exposed portion of the photoresist layer 50, except that the emissive layer 70 R There is no difference. In the process of forming the light-emitting layer, it is sufficient if the light-emitting layer 70R is formed, and the light-emitting layer 70R' does not necessarily have to be formed.

[0057] The light-emitting layer can be formed by using a dispersion of quantum dots (QDs) and applying separate coatings to each subpixel using methods such as spin coating or inkjet printing. The dispersion solvent contained in the quantum dot (QD) dispersion has an SP value lower than 12.0 and a polar term δ p Examples of dispersion solvents for quantum dots (QDs) include polar solvents with an SP value lower than 5.0 (low-polarity organic solvents). Examples of dispersion solvents for quantum dots (QDs) include isopropyl ether (SP value: 7.0, polarity term: 2.4), n-hexane (SP value: 7.3, polarity term: 0.1), cyclohexane (SP value: 8.2, polarity term: -0.2), carbon tetrachloride (SP value: 8.6, polarity term: 1.6), ethyl acetate (SP value: 8.6, polarity term: 4.4), toluene (SP value: 8.9, polarity term: 2.4), and tetrahydrofluoric acid. Examples include ran (SP value: 9.1, polarity term: 4), chloroform (SP value: 9.3, polarity term: 4.1), methylene chloride (SP value: 9.6, polarity term: 3.1), ethylene dichloride (SP value: 9.7, polarity term: 4.3), dioxane (SP value: 9.8, polarity term: 4.8), isopropyl alcohol (SP value: 10.2, polarity term: 3.9), and ethanol (SP value: 11.2, polarity term: 4.3).

[0058] The photoresist layer 50 has high resistance to polar solvents, as the water-soluble resin contains the aforementioned vinyl alcohol monomer units and other monomer units, resulting in an approximate SP value of 12.0 or higher, and preferably a polarity term of 5.0 or higher. This prevents unintended dissolution of the dispersion containing the quantum dots (QDs) by the dispersion solvent.

[0059] Figure 6 is a schematic diagram illustrating the process of removing the photoresist layer 50 by developing solution washing. In the peeling and developing process, the light-emitting layer 70R' along with the unexposed areas of the photoresist layer 50 is peeled off from the substrate 10 by the developing solution. As a result, the light-emitting layer 70R is developed on the photoresist layer 50 into the desired pattern.

[0060] In the process of peeling and developing, the developer solution used to completely dissolve the exposed areas of the photoresist layer 50 preferably has an SP value higher than 12 for the solvent contained in the developer solution. The above formula (1) Polarity term δ P It is more preferable that the value is 5.0 or higher. Examples of solvents that satisfy such conditions (highly polar organic solvents) include dimethylformamide (SP value: 11.5, polarity term: 6.4), methyl sulfoxide (SP value: 12.8, polarity term: 7.2), acetonitrile (SP value: 11.8, polarity term: 5.8), acetic acid (SP value: 12.4, polarity term: 6), methanol (SP value: 12.9, polarity term: 5.1), ethylene glycol (SP value: 14.7, polarity term: 6.9), PEGMEA (SP value: 15.9, polarity term: 4.7), N-methylpyrrolidone (SP value: 18, polarity term: 12.3), and water (SP value: 21, polarity term: 10.0). By using an organic solvent developer as the developer, the photoresist layer 50 can be successfully peeled off along with the light-emitting layer 70R' in its unexposed areas due to its high peelability, and the light-emitting layer 70R can be developed to have a desired pattern.

[0061] The developer solution may be supplied to the photoresist layer 50 by immersion in a beaker (developer solution tank) containing the developer solution, or by spraying the developer solution using a spray nozzle or the like.

[0062] Figure 8 is a schematic diagram illustrating the process from forming the photoresist layer 51 (second photoresist layer) to exposing the photoresist layer 51. The photomask 301 has a different pattern from the photomask 300 in order to avoid overlapping areas to be patterned.

[0063] The method for coating the photosensitive composition to form the photoresist layer 51 is the same as the method for coating the photosensitive composition to form the photoresist layer 50, so its explanation is omitted.

[0064] Figure 9 is a schematic diagram illustrating the process of forming a pattern on the photoresist layer 51 (second photoresist layer). As with the first development, an alkaline aqueous developer is preferable. In the second development process, the surface of the light-emitting layer 70R is covered with the photoresist layer 51, and is protected from the alkaline aqueous developer by the polar solvent resistance of the photoresist layer 51. In addition, the non-exposed areas of the photoresist layer 51 have increased polar solvent resistance, thus enabling high developability.

[0065] Figure 10 is a schematic diagram illustrating the process of forming the light-emitting layer 70B. The light-emitting layer 70B is identical to the light-emitting layer 70R except that it emits light with a center emission wavelength in the wavelength band between 400 nm and 500 nm, and that it is formed in a different location. The light-emitting layer 70B' is identical to the light-emitting layer 70B except that it is formed in an unexposed area of ​​the photoresist layer 51.

[0066] Figure 11 is a schematic diagram illustrating the process of removing the photoresist layer 51 by a second developer wash. In the peel-and-develop process, the photoresist layer 51, along with the unexposed areas, is peeled off from the substrate 10 by the developer due to its peelability.

[0067] Figure 12 is a schematic diagram illustrating the process of forming the photoresist layer 52 (the third photoresist layer). The photoresist layer 52 may have the same composition as the photoresist layer 50 and the photoresist layer 51, or it may have a different composition.

[0068] Figure 13 is a schematic diagram illustrating the process of exposing the photoresist layer 52 (the third photoresist layer). The photomask 302 has a different pattern from photomask 300 and photomask 301 in order to avoid overlapping of the light-emitting regions.

[0069] Figure 14 is a schematic diagram illustrating the process of forming a pattern on the photoresist layer 52 (the third photoresist layer). As with the first and second development, an alkaline aqueous developer is preferable. Here, the surfaces of the light-emitting layers 70R and 70B are covered with the photoresist layer 52, and are protected from the alkaline aqueous developer by the polar solvent resistance of the photoresist layer 52. In addition, the non-exposed areas of the photoresist layer 52 have increased polar solvent resistance, thus enabling high developability.

[0070] Figure 15 is a schematic diagram illustrating the process for forming the green light-emitting layer 70G. The light-emitting layer 70G is identical to the light-emitting layer 70R except that it emits light with a center emission wavelength in the wavelength band between 500 nm and 600 nm, and that it is formed in a different location. The light-emitting layer 70G' is identical to the light-emitting layer 70G except that it is formed in an unexposed area of ​​the photoresist layer 52.

[0071] Figure 16 is a schematic diagram illustrating the process of removing the photoresist layer 52 by a third developer wash. In the peel-developing process, the light-emitting layer 70G' along with the unexposed areas of the photoresist layer 52 is peeled off from the substrate 10 by the developer.

[0072] As shown in Figure 17, the light-emitting layer 70 R、A second charge transport layer 80, which is an electron transport layer, and a second electrode 90, which is a cathode, are formed on the substrate 10 on which 70B and 70G are formed. This results in a display device with multiple light-emitting elements, including a light-emitting element 100R comprising a first electrode 20 which is an anode, a first charge transport layer 30 which is a hole transport layer, an emitting layer 70R, a second charge transport layer 80, and a second electrode 90 which is a cathode; a light-emitting element 100B which has an emitting layer 70B instead of an emitting layer 70R; and a light-emitting element 100G which has an emitting layer 70G instead of an emitting layer 70R. 200 It is manufactured.

[0073] Although an embodiment in which the first electrode 20 is an anode has been described above, the first electrode is not limited to an anode in the manufacturing method of a light-emitting element according to one embodiment of the present disclosure. The light-emitting element manufactured by the manufacturing method according to one embodiment may have a forward-stacked structure, but is not limited to this, and may have an inverted-stacked structure. Therefore, the first charge transport layer may be an electron transport layer, and the second charge transport layer may be a hole transport layer. That is, the light-emitting element may have a configuration in which a first electrode which is a cathode, a first charge transport layer which is an electron transport layer, an emissive layer, a second electric transport layer which is a hole transport layer, and a second electrode which is an anode are stacked on a substrate in this order.

[0074] The light-emitting element may be of the top-emission or bottom-emission type. To create a top-emission type in a normal stacked structure, the anode should be made of an electrode material that reflects visible light, and the cathode should be made of an electrode material that transmits visible light. Conversely, to create a bottom-emission type, the anode should be made of an electrode material that transmits visible light, and the cathode should be made of an electrode material that reflects visible light.

[0075] The electrode material that reflects visible light is not particularly limited as long as it can reflect visible light and is conductive, but examples include metallic materials such as Al, Cu, Au, Mg, Li, and Ag, or alloys of the said metallic materials, or laminates of the said metallic material and transparent metal oxides (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.), or laminates of the said alloy and the said transparent metal oxide.

[0076] On the other hand, the electrode material that transmits visible light is not particularly limited as long as it can transmit visible light and is conductive, but examples include transparent metal oxides (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.), thin films made of metal materials such as Al and Ag, or nanowires made of metal materials such as Al and Ag.

[0077] For the film formation method of the first and second electrodes, general electrode formation methods can be used, such as physical deposition (PVD) methods including vacuum deposition, sputtering, EB deposition, and ion plating, or chemical deposition (CVD) methods. Furthermore, while not limited to, the patterning method for the first and second electrodes can include photolithography and inkjet methods. The positive-type photosensitive composition according to one embodiment of this disclosure can also be suitably used for patterning the first and second electrodes.

[0078] Furthermore, as a method for manufacturing the bank surrounding the light-emitting layer, for example, an organic material such as polyimide or acrylic is applied and then patterned by photolithography. The positive-type photosensitive composition according to one embodiment of this disclosure can also be suitably used for patterning the bank.

[0079] A hole transport layer is a layer that transports holes toward the light-emitting layer. Although not shown in the diagram, a hole transport layer may be composed of multiple hole transport layers. When a light-emitting element has multiple hole transport layers, one of the hole transport layers is sometimes referred to as a hole injection layer.

[0080] When the hole transport layer is a hole injection layer, examples of hole-injectable materials include nanoparticles such as NiO, CuI, Cu2O, CoO, Cr2O3, and CuAlS2. The nanoparticles that are the hole-injectable material may contain thiols or amines as ligands. These hole-injectable materials can be used as a dispersion to form the hole transport layer.

[0081] Furthermore, the material used in the hole transport layer is not particularly limited as long as it is a hole-transporting material that can stabilize the transport of holes to the light-emitting layer. Preferably, the hole-transporting material in the hole transport layer has high hole mobility. Moreover, it is preferable that the hole-transporting material is a material that can prevent electrons moving from the cathode from penetrating (electron-blocking material). This is because it is possible to increase the efficiency of hole and electron recombination within the light-emitting layer. The hole transport material is preferably a photosensitive hole transport material having a cationic polymerizable functional group such as an oxetane ring. Examples of photosensitive hole transport materials include N,N'-(4,4'-(cyclohexane-1,1-diyl)bis(4,1-phenylene))bis(N-(4-(6-(2-ethyloxetane-2-yloxy)hexyl)phenyl)-3,4,5-trifluoroaniline), N4,N4'-bis(4-(6-((3-ethyloxetane-3-yl)methoxy)hexyloxyphenyl)-N4,N4'-bis(4-methoxyphenyl)biphenyl-4,4'-diamine, and N4,N4'-bis(4-(6-((3-ethyloxetane-3-yl)methoxy)hexyl) Examples include phenyl)-N4,N4'-diphenylbiphenyl-4,4'-diamine. The photosensitive hole transport material contained in the hole transport layer may be cationically polymerized, for example, by a photoacid generator. The hole transport layer may also contain products generated when the photoacid generator is exposed to light. Other examples of hole transport materials include poly-TPD, polyvinylcarbazole (PVK), and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)](TFB). These hole transport materials can be used to form the hole transport layer, for example, as a dispersion or solution.

[0082] The dispersion of hole-injectable material and the dispersion of hole-transporting material may contain, for example, a polar solvent, such as ethanol. Here, the polar solvent is one that has an SP value lower than 12.0 and a polarity term lower than 5.0, similar to the dispersion of quantum dots (QDs). According to one embodiment of the positive-type photosensitive composition and the method for manufacturing a light-emitting element, not only is solvent resistance to the solvent contained in the dispersion of quantum dots (QDs) improved, but polar solvent resistance to the solvent contained in the dispersion of hole-injectable material and the dispersion of hole-transporting material is also improved.

[0083] All light-emitting layers, including the aforementioned light-emitting layers 70R, 70B, and 70G, emit light when recombination occurs between electrons and holes transported from the first or second electrode. In this embodiment, each light-emitting layer is a quantum dot light-emitting layer equipped with quantum dots (QDs: semiconductor nanoparticles) of different colors as the light-emitting material, but is not limited to this, and may also be an OLED (organic light-emitting diode).

[0084] The color of light emitted by each light-emitting layer differs depending on the emission center wavelength. In this embodiment, the multiple types of quantum dots are a combination of red quantum dots, green quantum dots, and blue quantum dots, but the combination does not necessarily have to be this one.

[0085] Each light-emitting layer may include, for example, a continuous film of a metal sulfide and a plurality of quantum dots embedded within the continuous film. The metal sulfide may be a sulfide semiconductor such as ZnS (zinc sulfide), ZnTeS, ZnMgS2, MgS, Ga2S3, ZnGa2S4, or MgGa2S4. The continuous film may have a thickness of 1000 nm in a plane perpendicular to the film thickness direction at any position in the film thickness direction of each light-emitting layer. 2 The above area may be present. Furthermore, the average film thickness of each light-emitting layer may be 10 nm or more and 100 nm or less, and the maximum film thickness of each light-emitting layer may be twice or less the minimum film thickness.

[0086] The quantum dots (QDs) contained in each light-emitting layer may have, for example, a core structure, a core / shell structure, a core / shell / shell structure, or a core / shell structure with continuously changing ratios. If the quantum dot (QD) has a core structure, a ligand is provided on the surface of the core, and if the quantum dot (QD) has a shell structure, a ligand is provided on the surface of the shell. The core portion of the quantum dot (QD) can be composed of, for example, Si, C, etc., in the case of a one-component system, for example, CdSe, CdS, CdTe, InP, GaP, InN, ZnSe, ZnS, ZnTe, etc., in the case of a ternary system, for example, CdSeTe, GaInP, ZnSeTe, etc., and in the case of a quaternary system, for example, AIGS, etc. In the case of a binary system, the shell can be composed of, for example, CdS, CdTe, CdSe, ZnS, ZnSe, ZnTe, etc., and in the case of a ternary system, it can be composed of, for example, CdSSe, CdTeSe, CdSTe, ZnSSe, ZnSTe, ZnTeSe, AIP, etc.

[0087] A quantum dot (QD) refers to a dot with a maximum width of 100 nm or less. The shape of a quantum dot (QD) is not particularly restricted and is not limited to a spherical three-dimensional shape (circular cross-sectional shape), as long as it satisfies the above maximum width. For example, it may have a polygonal cross-sectional shape, a rod-shaped three-dimensional shape, a branch-shaped three-dimensional shape, a three-dimensional shape with irregularities on the surface, or a combination thereof.

[0088] The ligand present in a quantum dot (QD) may be an inorganic ligand or an organic ligand. If the ligand present in a quantum dot (QD) is an organic ligand, it may be an organic compound having functional groups such as amines and thiols. A quantum dot (QD) may have the inorganic ligand described above, and may also have an organic ligand. Furthermore, if the ligand present in a quantum dot (QD) is an inorganic ligand, it may be, for example, a halogen ligand containing a halogen atom. In this case, the average concentration of halogen atoms within 1 nm from the outermost surface of each quantum dot (QD) may be 10%, 50%, or 100% higher than the average concentration of halogen atoms at other positions.

[0089] The light-emitting layer can be formed by using a dispersion of quantum dots and applying separate coatings to each subpixel using a spin-coating method or an inkjet method. The quantum dot dispersion contains a solvent such as n-hexane, toluene, or phenylcyclohexane, and may also contain a dispersion material such as thiols or amines.

[0090] If the light-emitting material of the light-emitting layer includes quantum dots that have a metal sulfide shell, which is a sulfide semiconductor, as an inorganic ligand, the quantum dots can be manufactured in an inert gas atmosphere as follows.

[0091] First, in order to obtain a precursor of sulfide semiconductors, a dispersion is prepared containing a metal acetate, metal nitrate, or metal halogen salt as a metal source, and thiourea, N-methylthiourea, or 1,3-dimethylthiourea as a sulfur source. The dispersion may also contain, as a precursor, a metal complex in which thiourea, N-methylthiourea, 1,3-dimethylthiourea, N,N'-dimethylthiourea, tetramethylthiourea, or thioacetamide is coordinated to a metal atom.

[0092] Next, a polar solvent in which an excess amount of halide ions dissolves relative to the quantum dots is mixed with a nonpolar solvent in which the quantum dots, to which carbon chains as organic ligands are coordinated, are dispersed, thereby replacing the organic ligands of the quantum dots with halide ions. Subsequently, the dispersion of the sulfide semiconductor precursor and the dispersion of quantum dots in which the organic ligands have been replaced with halide ions are mixed and stirred.

[0093] The polar solvent for producing quantum dots may include, for example, polar solvents such as dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF), esters or lactones such as methyl acetate, ethers such as tetrahydrofuran, tetrahydrothiophene, and diethyl sulfide, at least one of these. The nonpolar solvent is preferably, for example, toluene, hexane, octane, or octadecene, and is preferably a nonpolar solvent that is immiscible with the polar solvent for producing quantum dots.

[0094] When a dispersion of sulfide semiconductor precursors contains a polar solvent and a dispersion of quantum dots substituted with halide ions contains a nonpolar solvent, quantum dots comprising sulfide semiconductor shells as inorganic ligands can be generated in the polar solvent phase. As previously described, the resulting quantum dots can be dispersed in the polar solvent and used to form a light-emitting layer.

[0095] A dispersion of a polar solvent containing quantum dots is applied to a substrate and heated from 80°C to 500°C to form an emissive layer containing quantum dots that have sulfide semiconductor shells as inorganic ligands.

[0096] The electron transport layer is a layer that transports electrons from the cathode side toward the light-emitting layer. Although not shown in the diagram, an electron injection layer may be formed between the electron transport layer and the cathode. Examples of electron injection materials included in the electron injection layer include LiF.

[0097] The electron-transporting material included in the composition used to form the electron transport layer is not particularly limited as long as it is an electron-transporting material that can stabilize the transport of electrons to the light-emitting layer. Examples include nanoparticles of ZnO, ZnS, ZrO, MgZnO, AlZnO, TiO2, etc. These nanoparticles may have ligands such as organic ligands and inorganic ligands on their surface. Furthermore, these compositions may be applied collectively to multiple subpixels of a light-emitting element by methods such as spin coating and dip coating, or they may be applied separately to each subpixel by methods such as inkjet printing.

[0098] Here, the dispersion of the electron-transporting material may contain, for example, a polar solvent such as ethanol, and the polar solvent may be one with an SP value lower than 12.0 and a polarity term lower than 5.0, similar to the dispersion of quantum dots (QDs). According to one embodiment of the positive-type photosensitive composition and the method for manufacturing a light-emitting element, not only is the polar solvent resistance to the solvent contained in the dispersion of quantum dots (QDs) improved, but the polar solvent resistance to the solvent contained in the dispersion of the electron-transporting material is also improved. The electron-transporting material is used as a dispersion to form an electron-transport layer.

[0099] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Examples]

[0100] One embodiment of this disclosure is described below.

[0101] [1] Preparation of resin composition The sample composition was prepared using the materials listed in the [Materials] section below.

[0102] 〔material〕 (Water-soluble resin) PVA-PVP graft copolymer A-1 PVA ratio: 0.3 PVA-PVP graft copolymer A-2 PVA ratio 0.4 PVA-PVP graft copolymer A-3 PVA ratio 0.5 PVA-PVP graft copolymer B-1 PVA ratio: 0.6 PVA-PVP graft copolymer B-2 PVA ratio 0.7 PVA-PVP graft copolymer B-3 PVA ratio 0.8 Polyvinyl alcohol (PVA)-1 Polyvinylpyrrolidone (PVP)-1 The PVA ratio in water-soluble resins was calculated based on the following formula. PVA ratio=PVA / (PVA+PVP) PVA: Molar amount of monomer units constituting a PVA polymer unit PVP: Molar amount of monomer units constituting a PVP polymer unit. "PVA-PVP graft copolymer A" is a graft copolymer in which the hydroxyl groups of PVA in PVA-PVP are replaced with hydrophobic groups, while "PVA-PVP graft copolymer B" is a pure PVA-PVP graft copolymer in which the hydroxyl groups of PVA are not replaced with hydrophobic groups. (Positive-type photosensitive material) Positive-type photosensitive material A: 1,2-diazonaphthoquinone sulfonate ester of 2,3,4-trihydroxybenzophenone; Positive type photosensitive material B: 1,2-diazonaphthoquinone sulfonate ester of 2,3,4,4'-tetrahydroxybenzophenone; Positive-type photosensitive material C: 6-diazo-5,6-dihydro-5-oxo-1-naphthalene sulfonate of 4,4'-(1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene)diphenol In all of the positive-type photosensitive agents A to C, the conversion rate to sulfonic acid esters was approximately 100%. (Other materials) Solvent: Dimethyl sulfoxide (DMSO)

[0103] [2] Evaluation of the photoresist layer [2-1] Evaluation of positive-type photosensitive materials 5 g of PVA-PVP graft copolymer A-2 was weighed and dissolved in 100 mL of DMSO to obtain a water-soluble resin solution. This prepared the composition of Sample 7 (Comparative Example). Subsequently, the positive-type photosensitive compositions of Samples 1 to 6 were prepared by mixing the solution prepared in the same manner as the composition of Sample 7 with positive-type photosensitive agents A to C under light-shielding conditions, so that the mass ratio of positive-type photosensitive agents was 17:3 (15% by mass added) or 7:3 (30% by mass added), so that the amount of positive-type photosensitive agent added was as shown in Table 1.

[0104] Sample 1 was coated onto a glass substrate (2.5 cm × 2.5 cm) by spin coating, and then heated and dried at 80°C for 3 minutes. This formed a photoresist layer on the glass substrate from the positive-type photosensitive composition of Sample 1. Subsequently, following the same procedure as for Sample 1, photoresist layers from the positive-type photosensitive compositions of Samples 2-6 and the layer of comparative Sample 7 were formed on the glass substrate as separate samples. The film thickness of the photoresist layers of Samples 1-6 and the layer of comparative Sample 7 were approximately 1 μm.

[0105] Next, the samples were immersed in an alkaline aqueous solution (0.8% by mass TMAH) at room temperature (23°C) for 30 seconds, then removed and dried by N2 blowing. After that, the film thickness of the photoresist layer was measured again. Table 1 shows the evaluation results for the positive-type photosensitive agent, the amount added, and the reduction in film thickness contained in the photosensitive compositions of Samples 1 to 7.

[0106] [Table 1]

[0107] In all of samples 1-6, the addition of 30% by mass suppressed film thickness reduction more effectively than the addition of 15% by mass. It was observed that the higher the amount of additive, the greater the number of diazo-coupled areas in the unexposed regions. Therefore, it is judged that this can improve the retention rate of film thickness in the unexposed regions that are desired to remain after exposure, improving polar solvent resistance, and that it can create clear patterns in terms of developability.

[0108] [2-2] Evaluation of ease of peeling A positive-type photosensitive composition of Sample 6 was prepared separately and coated onto a glass substrate (2.5 cm × 2.5 cm) by spin coating under light-shielding conditions, and then heated and dried at 80°C for 3 minutes. This formed a photoresist layer on the glass substrate from the positive-type photosensitive composition of Sample 6. Similarly, a negative-type photoresist layer was prepared for comparative Sample 6C using a negative-type photosensitive composition manufactured by Company T, following the same procedure as for the positive-type photosensitive composition of Sample 6. The film thickness of the photoresist layer of the positive-type photosensitive composition of Sample 6 and the negative-type photoresist layer of Sample 6C were approximately 2 μm. The composition of the negative-type photosensitive composition manufactured by Company T is as follows. Acrylic resin: 40% by mass Photoinitiator: 5% by mass Solvent 1 PGMEA: 50% by mass, Solvent 2: Isopropanol: 5% by mass

[0109] Next, the ease of peeling after pattern formation was evaluated for both the positive-type photoresist layer formed from the positive-type photosensitive composition of Sample 6 and the negative-type photoresist layer formed from the negative-type photosensitive composition of Comparative Sample 6C. For the evaluation of peelability, the positive-type photoresist layer of Sample 6 was formed on the unexposed area of ​​the photoresist layer outside the pattern on the glass substrate under no exposure conditions, while the negative-type photoresist layer of Sample 6C was exposed using g-line radiation at an exposure dose of 240 mJ / cm². 2 The process was carried out under these conditions, and a photoresist layer outside the pattern was formed on the glass substrate.

[0110] For each of the photoresist layers of Sample 6 and Sample 6C, immersion in DMSO at approximately 23°C (room temperature) for 60 seconds was performed, followed by removal and N2 blow drying at 23°C. The film thickness of the photoresist layers of Sample 6 and Sample 6C was then measured. Next, the water dissolution rate was calculated based on the difference between the film thickness before immersion and the immersion time in DMSO. Table 2 shows the evaluation results of the DMSO dissolution rates of the photoresist layers of Sample 6 and Sample 6C.

[0111] [Table 2]

[0112] As shown in Table 2, the photoresist layer formed from the positive-type photosensitive composition of Sample 6 is, as a positive-type photoresist layer, 6C Compared to the negative-type photoresist layer, we confirmed that DMSO (SP value: 12.8, polarity term: 7.2) has superior peelability, allowing for faster peeling and development after patterning.

[0113] [2-3] Evaluation of water-soluble resins The water-soluble resin layers contained in the photoresist layer were prepared using samples 8-13 as reference examples and samples 14 and 15 as comparative examples, and their water dissolution rates were evaluated. First, 5 g of PVA-PVP graft copolymer A-1 was weighed and dissolved in 100 mL of DMSO to obtain a solution of PVA-PVP graft copolymer A-1. This prepared the composition of sample 8.

[0114] Sample 9 was prepared following the same procedure as for Sample 8, except that PVA-PVP graft copolymer A-1 was replaced with PVA-PVP graft copolymer A-2. Similarly, Samples 10-15 were prepared by replacing PVA-PVP graft copolymer A-1 with PVA-PVP graft copolymer A-3, PVA-PVP graft copolymer B-1, PVA-PVP graft copolymer B-2, PVA-PVP graft copolymer B-3, polyvinyl alcohol-1, and polyvinylpyrrolidone-1, respectively.

[0115] Water-soluble resin compositions of samples 8-15 were coated onto a glass substrate (2.5 cm x 2.5 cm) using a spin-coating method, and then heated and dried at 80°C for 3 minutes.

[0116] For each of the water-soluble resin layers in the photoresists of samples 8-15, the samples were immersed in pure water (at room temperature of approximately 23°C) for 60 seconds, then removed and N2 blow-dried at room temperature of 23°C. The film thickness of the water-soluble resin layer for the photoresist was then measured. Next, the water dissolution rate was calculated based on the difference between the film thickness before immersion and the immersion time in pure water. Table 3 shows the evaluation results for the water-soluble resin, PVA ratio, and water dissolution rate in the water-soluble resin layer for the photoresists of samples 8-15.

[0117] [Table 3]

[0118] As shown in Table 3, the water-soluble resin layers for photoresists in samples 8-13 had a water dissolution rate of 50 nm / second or higher, and it was confirmed that a higher PVA ratio was preferable from the viewpoint of film thickness control. Furthermore, samples 8-10, in which a portion of the PVA was derivatized, had a lower PVA ratio compared to samples 11-13, yet... ,shadowThe water dissolution rate was suppressed by Hibiki. In contrast, the water-soluble resin layer of sample 14 containing polyvinyl alcohol-1 had a slow water dissolution rate of 30 nm / second, while the water-soluble resin layer of sample 15 containing polyvinylpyrrolidone-1 had an excessively fast water dissolution rate of 1000 nm / second. From these results, it is expected that the water-soluble resin used in positive-type photosensitive compositions should be copolymer rather than a water-soluble homopolymer, from the viewpoint of film thickness control, i.e., developability and resistance to polar solvents. [Explanation of symbols]

[0119] 10 circuit boards 20 First electrode (anode) 30. First charge transport layer (hole transport layer) 40 Bank 50, 51, 52 Photoresist layer (coating) 70R, 70B, 70G, 70R', 70B', 70G' Emitting layer 80. Second charge transport layer (electron transport layer) 90 Second electrode (cathode) 100R, 100B, 100G light-emitting elements 200 Display device 300, 301, 302 Photomasks

Claims

1. A manufacturing method for manufacturing a light-emitting element on a substrate, A step of coating a substrate with a composition comprising a water-soluble resin, a positive-type photosensitive agent, and a solvent, wherein the water-soluble resin comprises a copolymer containing vinyl alcohol monomer units and water-soluble monomer units. A step of exposing the coated composition, A step of washing the exposed composition with a developer and developing a pattern of the composition on the substrate, A step of forming an emissive layer on the substrate on which the pattern has been developed, The process includes the step of peeling off and developing the composition remaining on the substrate on which the light-emitting layer is formed using a solvent, The solvent has a solubility parameter (δ) of 12.0 or higher, as shown in the following formula (1); δ (solubility parameter) = (δ ｄ ２ +δ Ｐ ２ +δ ｈ ２ ) １／２ …(1); In formula (1), δ ｄ is the dispersion term, δ Ｐ is the polarity term, δ ｈ is the hydrogen bonding term, and the manufacturing method thereof.

2. The solvent is δ in formula (1) above. Ｐ The manufacturing method according to claim 1, wherein the coefficient is 5.0 or higher.

3. In the step of forming the light-emitting layer, the light-emitting layer is formed by coating a dispersion containing a light-emitting material and a dispersion solvent. The manufacturing method according to claim 1 or 2, wherein the dispersion solvent includes a solvent in which the δ (solubility parameter) shown in formula (1) is less than 12.0.

Images