Method for manufacturing a light-emitting element

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

Composition and method for manufacturing light-emitting element using the same

[0001] The present disclosure relates to a composition and a method for manufacturing a light-emitting device using the same. More specifically, the present disclosure relates to a composition containing a water-soluble resin copolymer and a diazoquinone compound, and a method for manufacturing a light-emitting device using the same.

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

[0003] Japanese Patent Application Publication No. 05-011405

[0004] However, in the case of a positive-type photosensitive composition as described in Patent Document 1, the non-exposed portion after patterning is easily dissolved in a polar solvent in the production of a coating-layered device such as an organic electroluminescent device, and this causes a problem in the developability of the pattern. In contrast, for example, a negative-type photosensitive composition has higher polar solvent resistance to the polar solvent in the exposed portion than a positive-type photosensitive composition, but has the problem that it is difficult to peel off and remove after patterning.

[0005] Therefore, there is a demand for a positive photosensitive composition that can form a photoresist layer that is highly resistant to polar solvents without impairing strippability.

[0006] One aspect of the present disclosure has been made in consideration 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 polar solvent-based functional layer materials, and that has high peelability as a positive photoresist, while also having developability and polar solvent resistance.

[0007] In order to solve the above problems, a composition according to one embodiment of the present disclosure includes a water-soluble resin, a positive photosensitizer, and a solvent, and the water-soluble resin includes a vinyl alcohol monomer unit and a water-soluble monomer unit.

[0008] Furthermore, a manufacturing method for a light-emitting element according to one embodiment of the present disclosure includes the steps of applying the composition onto a substrate, exposing the applied composition to light, washing the exposed composition with a developer and developing a pattern of the composition on the substrate, forming a light-emitting layer on the substrate on which the pattern has been developed, and peeling and developing the composition remaining on the substrate on which the light-emitting layer has been formed using a solvent.

[0009] According to one aspect of the present disclosure, it is possible to provide a composition capable of forming a photoresist layer that has high peelability as a positive photoresist layer, as well as developability and polar solvent resistance.

[0010] FIG. 1 is a cross-sectional view showing an outline of a step included in a method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. FIG. 2 is a cross-sectional view showing an outline of a step of forming a photoresist layer 50, included in the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. FIG. 3 is a cross-sectional view showing an outline of a step of exposing the photoresist layer 50, included in the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. FIG. 4 is a cross-sectional view showing an outline of a step of developing a pattern in the exposed photoresist layer 50, included in the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. FIG. 5 is a cross-sectional view showing an outline of a step 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. FIG. 6 is a cross-sectional view showing an outline of a step of peeling and developing the first light-emitting layer 70R, included in the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. FIG. 7 is a cross-sectional view showing an outline of a step of forming a photoresist layer 51 (a step of forming a second composition), included in the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. FIG. 8 is a cross-sectional view showing an outline of a step of exposing the photoresist layer 51 (a second exposure step), included in the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. 1 is a cross-sectional view showing an outline of a step of forming a second light-emitting layer 70B (a step of forming a second light-emitting layer), which is included in the method for manufacturing a light-emitting device according to embodiment 2 of the present disclosure. FIG. 2 is a cross-sectional view showing an outline of a step of peeling and developing the second light-emitting layer 70B (a second peel-and-develop step), which is included in the method for manufacturing a light-emitting device according to embodiment 2 of the present disclosure. FIG. 3 is a cross-sectional view showing an outline of a step of forming a photoresist layer 52 (a step of forming a third composition), which is included in the method for manufacturing a light-emitting device according to embodiment 2 of the present disclosure. FIG. 4 is a cross-sectional view showing an outline of a step of exposing the photoresist layer 52 (a third exposing step), which is included in the method for manufacturing a light-emitting device according to embodiment 2 of the present disclosure. FIG. 5 is a cross-sectional view showing an outline of a step of developing a pattern in the photoresist layer 52 (a third developing step), which is included in the method for manufacturing a light-emitting device according to embodiment 2 of the present disclosure.1 is a cross-sectional view showing an outline of a step of peeling and developing a third light-emitting layer 70G (a third peel-and-develop step), which is included in the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure. 2 is a cross-sectional view showing an outline of a display device 200 including a plurality of light-emitting elements 100R, 100B, and 100G manufactured by the method for manufacturing a light-emitting element according to embodiment 2 of the present disclosure.

[0011] [Embodiment 1: Positive Photosensitive Composition] Hereinafter, one embodiment of the present disclosure will be described in detail.

[0012] A positive photosensitive composition (composition) according to one embodiment of the present disclosure contains 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 water-soluble thermoplastic resin that dissolves in pure water and an alkaline aqueous solution, and may contain a copolymer containing a vinyl alcohol monomer unit. The water-soluble resin is a copolymer containing two or more types of monomer units, namely, a vinyl alcohol monomer unit and another monomer unit, and the vinyl alcohol monomer unit and the other monomer unit are monomer units derived from a water-soluble monomer.

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

[0015] The water-soluble resin may have its water solubility adjusted by substituting some of the hydrogen atoms in the hydroxyl groups of the polymer units obtained by polymerizing vinyl alcohol monomer units, i.e., the vinyl alcohol polymer units, with hydrophobic groups. Examples of the 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, and is preferably a block copolymer or graft copolymer containing vinyl alcohol polymer units formed by polymerization of vinyl alcohol monomer units and polymer units derived from water-soluble monomer units other than the vinyl alcohol polymer units, more preferably a graft copolymer. By using a water-soluble resin that is 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 difference in water solubility of each monomer unit, thereby controlling the developability and polar solvent resistance of the photoresist layer described below. Furthermore, the photoresist layer can be provided with high peelability as a positive 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 (hereinafter referred to as a second polymer unit) having a water solubility relatively different from that of the vinyl alcohol polymer unit. More specifically, for example, the film-forming property of the water-soluble resin can be controlled by adjusting the ratio of the molar amount of the monomer unit contained in the first polymer unit, assuming that the sum of the molar amounts of the monomer units contained in the first polymer unit and the second polymer unit is 1.0, and thereby controlling the developability and polar solvent resistance of the photoresist layer described later.

[0018] The vinyl alcohol polymer unit is the first polymer unit contained in the water-soluble resin, and its ratio is referred to 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 polar solvent resistance of the unexposed portion of the photoresist layer formed from the positive photosensitive composition. This prevents the unexposed portion of the photoresist layer from being excessively removed 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 portion of the photoresist layer. The ratio of the vinyl alcohol polymer unit to the second polymer unit in the block copolymer or graft copolymer may be adjusted in accordance with a PVA ratio value of 0.3 to 0.9.

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

[0020] The SP value of the second polymer unit can be divided into three terms 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 polar term, δ Ｈ is a hydrogen bond term.) The polymer unit of the water-soluble resin is a parameter shown in formula (1), and the polar term δ Ｐ The polarity term δ is preferably 5.0 or more from the viewpoint of increasing the polar solvent resistance of the photoresist layer to an organic solvent developer and also increasing the dissolution resistance to an alkaline aqueous developer (which is also an example of polar solvent resistance). Ｐ can be obtained from, for example, Hansen Solubility Parameter Estimation Software, and the polarity term δ of the monomer constituting the water-soluble resin Ｐand the molar ratio of the monomer units contained in the water-soluble resin.

[0021] The type of monomer unit constituting the second polymer unit contained in the water-soluble resin may be selected based on the water solubility of the homopolymer of each monomer unit. The water solubility of the homopolymer of each monomer unit may be roughly calculated 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 between the water solubility of the first polymer unit and the water solubility of the second polymer unit (SP value difference) 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 an SP value of, for example, 9.0 or more, preferably 25.8 or more. Examples of such monomers include (meth)acrylic acid (SP: 9.6), (meth)acrylates, (meth)acrylamide (SP value: 9 to 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. Examples of monomer units derived from these monomers include monomer units derived from (meth)acrylic acid, monomer units derived from (meth)acrylates, monomer units derived from (meth)acrylamide, and monomer units derived from N-vinylacetamide. Other examples of the monomer unit include an ethylene oxide unit, a propylene oxide unit, an ethyleneamine unit, a propyleneamine unit, and the like. The water-soluble monomer unit constituting the second polymer unit may be, for example, a monomer unit derived from a monomer having a hydrophilic group such as a carboxyl group, a hydroxyl group, an amino group, or an amide group, or may be a monomer unit that, upon polymerization, forms a hydrophilic main chain exemplified by a polyether chain such as polyethylene glycol, or a polyamine chain such as spermine or spermidine.

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

[0024] [Positive Photosensitive Agent] A positive photosensitive agent is, for example, decomposed (also called depolymerization) by irradiation with light, and releases protons (H ＋Any compound capable of producing a carboxylic acid group and an organic compound having an acid group such as a carboxylic acid group or a sulfonic acid group may be used. For example, organic compounds having a carboxylic acid group include indenecarboxylic acid, phthalic acid, and derivatives thereof. The positive photosensitizer may typically be a diazoquinone compound. Therefore, the following description of the positive photosensitizer will be given using a typical example of a diazoquinone compound. Examples of diazoquinone compounds include diazoquinones such as diazobenzoquinone (DBQ) and diazonaphthoquinone (DNQ), and derivatives thereof.

[0025] By using a diazoquinone compound as a positive photosensitizer, the polar solvent resistance of the non-exposed portion of the photoresist layer is increased, and the photoresist layer is heated to a polarity term δ Ｐ The strippability with a solvent having a viscosity of 5.0 or more is improved. Furthermore, by including a diazoquinone compound, high strippability as a positive photoresist layer can be imparted.

[0026] The diazoquinone derivative may be, for example, a compound in which a diazoquinone moiety and a residue derived from a compound having a hydroxyl group or an amino group are bonded via an ester bond or an amide bond. Here, the diazoquinone moiety may have, for example, a sulfonyl group to form the ester bond or the amide bond. The diazoquinone compound may be a compound having an ester bond or an amide bond derived from the sulfonyl group of the diazoquinone moiety and the hydroxyl group or the amino group of the compound. Here, the residue derived from a compound having a hydroxyl group means an alcohol residue, and the residue derived from a compound having an amino group means an amine residue.

[0027] When a compound that forms an ester bond or an amide bond with a diazoquinone moiety has a divalent or higher hydroxyl group or amino group, 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 a developer before and after exposure, thereby controlling the developability and polar solvent resistance. The conversion rate of the diazoquinone moiety is defined as the conversion rate of a hydroxyl group in the compound to an ester bond, or the conversion rate of an amino group in the compound to an amide bond, and is calculated using the following formula: (number of moles of diazoquinone moiety) / (number of moles of hydroxyl groups and amino groups in the compound before conversion to diazoquinone moiety) × 100

[0028] Derivatives of diazoquinone include, for example, azoquinone sulfonates and azoquinone sulfonamides.

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

[0030] In the diazoquinone compound, the compound for forming the residue (alcohol residue) derived from the compound having a hydroxyl group can be a compound having a phenolic hydroxyl group.The compound having a phenolic hydroxyl group can be a phenol having a monovalent hydroxyl group, such as phenol, naphthol, etc., a phenol having a divalent or higher hydroxyl group, such as catechol, pyrogallol, etc., a phenol having a divalent or higher phenolic hydroxyl group, such as bisphenol, trisphenol, tetrakisphenol, etc., or a phenolic resin, such as novolac phenolic resin. Examples of compounds having a phenolic hydroxyl group include 4,4',4"-ethylidynetrisphenol, 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, examples of the diazoquinone compound include diazoquinone sulfonamides, which are compounds formed by introducing a 1,2-benzoquinonediazo 4-sulfonyl group or the like into an amino group introduced into a resin by forming an ester bond between a hydroxyl group of an amino alcohol and a resin having a carboxyl group, thereby forming a sulfonamide.

[0032] In the positive photosensitive composition, the content of the diazoquinone compound is preferably 15% by mass or more, more preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more, based on 100% by mass of the total of the water-soluble resin and the diazoquinone compound. Although not limited thereto, the content of the diazoquinone compound may be 90% by mass or less.

[0033] In addition, the positive photosensitizer contained in the positive photosensitive composition is not limited to the above-mentioned diazoquinone compound. The positive photosensitizer may be, for example, at least one positive photosensitizer selected from the group consisting of the above-mentioned diazoquinone compound, polyolefin sulfone, and polyphthalaldehyde. The polyolefin sulfone may be a photosensitive polyolefin sulfone, for example, a photosensitive polyolefin sulfone in which a dye that generates an amine upon absorbing light is introduced into the side chain of the polyolefin sulfone via the carbon bonded to the sulfone group in the polyolefin sulfone chain. Furthermore, the polyphthalaldehyde may be a photosensitive polyphthalaldehyde, for example, polyphthalaldehyde (PPA) and photosensitive polyphthalaldehyde such as polyphthalaldehyde having an oxime ether terminal.

[0034] [Solvent] Examples of the solvent contained in the positive 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), and two or more of these solvents may be used in combination.

[0035] [Crosslinking Agent] The positive photosensitive composition may contain a crosslinking agent. The crosslinking agent may be a crosslinking agent that crosslinks with the acid generated when the diazoquinone compound contained in the positive photosensitive composition is exposed to light. Examples of the crosslinking agent include novolac phenolic resins, epoxy resins, melamine resins, unsaturated polyester resins, polyimide resins, diallyl phthalate, and urethane resins. By controlling the content of the crosslinking agent and the baking conditions when forming the photoresist layer, the degree of crosslinking can be controlled, thereby controlling the solubility and achieving a more accurate pattern. When the positive photosensitive composition contains a crosslinking agent, the content of the crosslinking agent is not limited, but may be, for example, more than 0 parts by mass, preferably 100 parts by mass or less, and more preferably 50 parts by mass or less, based on 100 parts by mass of the total of the water-soluble resin and the diazoquinone compound.

[0036] [Other Additives] The composition for forming a photoresist layer may further contain additives such as a photosensitizer such as acetophenone, a chemical sensitizer, a filler, a colorant, a stabilizer such as an antioxidant, and a surfactant such as a leveling agent, an antifoaming agent, or a dispersant.

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

[0038] The photoresist layer, which is a coating film formed by coating a positive photosensitive composition, is determined by the SP value and polarity term δ of the solvent. ｐ For example, in the unexposed area of ​​the photoresist layer, the dissolution rate of dimethyl sulfoxide (polarity term δ ｐ The dissolution rate in dimethyl sulfoxide (DMSO) is preferably 10 nm / sec or more, more preferably 50 nm / sec or more, at room temperature (23° C.), and is not limited thereto, but may be 2000 nm / sec or less.

[0039] The photoresist layer, which is a coating film formed from a positive photosensitive composition, is heated in a low temperature atmosphere with ethanol (polarity term δ ｐ The dissolution rate in ethanol (4.3) at room temperature (23° C.) should be 10 nm / sec or less, and preferably 5 nm / sec or more. The dissolution rate in ethanol should be 20 nm / sec or less, although this is not a limitation.

[0040] The dissolution rate in dimethyl sulfoxide and the dissolution rate in ethanol of the unexposed portion of the photoresist layer may be evaluated in accordance with the "Evaluation of film thickness reduction amount" described in the Examples of the present disclosure, and may be calculated from the evaluation results of the film thickness reduction amount.

[0041] The photoresist layer formed from the positive photosensitive composition has a polarity term δ , which is exemplified by ethanol, as will be described later. ｐ However, the polar solvent resistance to polar solvents with a polarity of 5.0 or less is improved.

[0042] Embodiment 2: Method for manufacturing a light-emitting element Another embodiment of the present disclosure will be described below.

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

[0044] As shown in FIG. 1, a first electrode 20 and a first charge transport layer 30 are formed on a substrate 10 in a state where they are partitioned into banks 40 .

[0045] The substrate 10 may be a resin substrate made of a resin material such as polyimide, or 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 may be either an anode or a cathode, but is not limited thereto. In this embodiment, the first electrode 20 is an anode.

[0047] The first charge transport layer 30 may be a hole transport layer or an electron transport layer, but is not limited thereto. In this embodiment, the first charge transport layer 30 is a hole transport layer. The first charge transport layer 30, which is a hole transport layer, may be formed from a composition containing a hole injection material or a hole transport material, which will be described later.

[0048] The bank 40 may be formed in advance before the formation of the electrodes in order to insulate the first electrodes 20 from each other.

[0049] 2 is a diagram illustrating an outline of a process for forming a photoresist layer 50. The photoresist layer 50 is formed from a positive photosensitive composition according to one embodiment of the present disclosure.

[0050] The positive-type photosensitive composition is applied to the subpixels of the light-emitting elements collectively by dip coating, spin coating, or the like, thereby forming a photoresist layer 50. The photoresist layer 50 may then be heated and dried, for example, at a temperature in the range of 80 to 150°C. The positive-type photosensitive composition is not limited to being applied to the subpixels collectively; it may also be applied separately to each subpixel, for example, by an inkjet method. Heating the photoresist layer 50 can promote diazo coupling of the diazoquinone compound. This increases the number of bonding points in the photoresist layer 50, thereby improving polar solvent resistance. Furthermore, the hydroxyl groups of the vinyl alcohol monomer units react with the acid compound formed from the diazo compound to form an ester, thereby improving polar solvent resistance.

[0051] After the photoresist layer 50 has been dried by heating, the photoresist layer 50 formed on the first charge transport layer 30 may be exposed to light using a photomask 300 having a desired pattern, as shown in FIG. 3. Examples of light for exposing the photoresist layer 50 include ultraviolet light having a wavelength of about 150 to 450 nm, and electron beams. The ultraviolet light may be g-rays (wavelength 436 nm), h-rays (wavelength 405 nm), or i-rays (wavelength 365 nm) from a high-pressure mercury lamp, or may be an excimer laser (wavelength 150 to 248 nm). The exposure dose is not limited, but may be, for example, 1 mJ / cm. ２ ~1000mJ / cm ２ This allows sufficient exposure from the photoresist layer 50 to the surface of the first charge transport layer 30.

[0052] FIG. 4 is a diagram illustrating an outline of the process of washing the photoresist layer 50 with a developer and developing a pattern in the exposed areas of the photoresist layer 50. Acidic compounds, such as derivatives of indenecarboxylic acid, are generated in the exposed areas of the photoresist layer 50, thereby increasing its solubility in an alkaline aqueous developer. Therefore, a desired pattern can be developed in the photoresist layer 50 by washing with an alkaline aqueous developer. The photoresist layer 50 remaining in the unexposed areas contains a water-soluble resin containing polymer units formed by polymerization of vinyl alcohol monomer units, and the diazoquinone compound has many diazo coupling bonding points, thereby enhancing solvent resistance. This prevents excessive dissolution of the photoresist layer 50 during development with an alkaline aqueous developer. Furthermore, the unexposed areas of the photoresist layer 50 have enhanced polar solvent resistance, enabling high developability that allows for the realization of patterns with clear contrast.

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

[0054] The developer is preferably an alkaline aqueous developer, and examples of the alkaline aqueous developer include aqueous developers containing alkalis such as potassium hydroxide (KOH) and tetramethylammonium hydroxide (TMAH). Aqueous developers such as alkaline aqueous developers are water-based polar solvents even if they have high SP values ​​and polarity terms, and the unexposed portions of the photoresist layer 50 also have increased polar solvent resistance to the alkaline aqueous developer.

[0055] After development, the photoresist layer 50 may be dried by heating at a temperature of, for example, 50 to 150°C.

[0056] 5 is a diagram illustrating an outline of the process of forming a light-emitting layer 70R on a pattern formed in a photoresist layer 50. The light-emitting layer 70R can be formed by applying a composition containing a light-emitting material onto the photoresist layer 50 on which a pattern has been formed. The light-emitting layer 70R' is no different from the light-emitting layer 70' except that the light-emitting layer 70R is provided in the non-exposed portion of the photoresist layer 50. In the process of forming the light-emitting layer, it is sufficient that the light-emitting layer 70R is formed, and the light-emitting layer 70R' is not necessarily formed.

[0057] The light-emitting layer can be formed by applying a dispersion liquid containing quantum dots (QDs) to each subpixel by a spin coating method, an inkjet method, or the like. The dispersion solvent contained in the quantum dot (QD) dispersion liquid has an SP value of less than 12.0 and a polarity term δ ｐExamples of the dispersion solvent for quantum dots (QDs) include isopropyl ether (SP value: 7.0, polarity: 2.4), n-hexane (SP value: 7.3, polarity: 0.1), cyclohexane (SP value: 8.2, polarity: -0.2), carbon tetrachloride (SP value: 8.6, polarity: 1.6), ethyl acetate (SP value: 8.6, polarity: 4.4), toluene (SP value: 8.9, polarity: 2.4), tetrahydrofuran (SP value: 8.9, polarity: 2.4), and the like. Examples of such solvents include orthoquinone (SP value: 9.1, polarity: 4), chloroform (SP value: 9.3, polarity: 4.1), methylene chloride (SP value: 9.6, polarity: 3.1), ethylene dichloride (SP value: 9.7, polarity: 4.3), dioxane (SP value: 9.8, polarity: 4.8), isopropyl alcohol (SP value: 10.2, polarity: 3.9), and ethanol (SP value: 11.2, polarity: 4.3).

[0058] The photoresist layer 50 has a water-soluble resin containing the vinyl alcohol monomer unit and other monomer units, and therefore has an SP value of approximately 12.0 or more, and preferably a polarity term of 5.0 or more, which provides high polar solvent resistance and prevents unintended dissolution of the dispersion liquid containing dispersed quantum dots (QDs) by the dispersion solvent.

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

[0060] The developer used in the peel-and-develop process dissolves all exposed areas of the photoresist layer 50, so the SP value of the solvent contained in the developer is preferably higher than 12, and the polarity term δ calculated by the following formula (1) is ＰIt is more preferable that the polarity of the solvent (highly polar organic solvent) satisfying such conditions is 5.0 or more. Examples of solvents (highly polar organic solvents) that satisfy such conditions include dimethylformamide (SP value: 11.5, polarity: 6.4), methyl sulfoxide (SP value: 12.8, polarity: 7.2), acetonitrile (SP value: 11.8, polarity: 5.8), acetic acid (SP value: 12.4, polarity: 6), methanol (SP value: 12.9, polarity: 5.1), ethylene glycol (SP value: 14.7, polarity: 6.9), PEGMEA (SP value: 15.9, polarity: 4.7), N-methylpyrrolidone (SP value: 18, polarity: 12.3), and water (SP value: 21, polarity: 10.0). By using an organic solvent developer as the developer, the photoresist layer 50 has high peelability, so that the unexposed portions can be successfully peeled off together with the light-emitting layer 70R', and the light-emitting layer 70R can be developed to have the desired pattern.

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

[0062] 8 is a diagram illustrating an outline of the process from the step of forming the photoresist layer 51 (second photoresist layer) to the step of exposing the photoresist layer 51. The photomask 301 has a pattern different from that of the photomask 300 in order to avoid overlapping of the patterned regions.

[0063] The method for applying the photosensitive composition to form the photoresist layer 51 is the same as the method for applying the photosensitive composition to form the photoresist layer 50, and therefore a description thereof will be omitted.

[0064] 9 is a diagram illustrating an outline of the process of forming a pattern in the photoresist layer 51 (second photoresist layer). As with the first development, an alkaline aqueous developer is preferably used. In the second development process, the surface of the light-emitting layer 70R is covered with the photoresist layer 51, and is therefore protected from the alkaline aqueous developer by the polar solvent resistance of the photoresist layer 51. Furthermore, the non-exposed portions of the photoresist layer 51 have increased polar solvent resistance, allowing for high developability.

[0065] 10 is a diagram illustrating an outline of the process for forming the light-emitting layer 70B. The light-emitting layer 70B is identical to the light-emitting layer 70R, except that it emits light having a central emission wavelength in a wavelength band exceeding 400 nm and not exceeding 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] 11 is a diagram illustrating an outline of the step of removing the photoresist layer 51 by second developer washing. In the peel-and-develop step, the peel-and-removal properties of the photoresist layer 51 allow the light-emitting layer 70B′ to be peeled off from the substrate 10 together with the unexposed portion by the developer.

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

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

[0069] 14 is a diagram illustrating an outline of the process of forming a pattern in the photoresist layer 52 (third photoresist layer). As with the first and second developments, an alkaline aqueous developer is preferably used. Here, the surfaces of the light-emitting layers 70R and 70B are covered with the photoresist layer 52, and are therefore protected from the alkaline aqueous developer by the polar solvent resistance of the photoresist layer 52. Furthermore, the non-exposed portions of the photoresist layer 52 have enhanced polar solvent resistance, allowing for high developability.

[0070] 15 is a diagram illustrating an outline of the process for forming green light-emitting layer 70G. Light-emitting layer 70G is identical to light-emitting layer 70R, except that it emits light having a central emission wavelength in a wavelength band exceeding 500 nm and not exceeding 600 nm, and that it is formed in a different location. Light-emitting layer 70G' is identical to light-emitting layer 70G, except that it is formed in an unexposed area of ​​photoresist layer 52.

[0071] 16 is a diagram illustrating an outline of the step of removing the photoresist layer 52 by washing with the developer for the third time. In the peel-and-develop step, the light-emitting layer 70G′ is peeled off from the substrate 10 together with the unexposed portion of the photoresist layer 52 by the developer.

[0072] 17 , 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 the light-emitting layer 70R, 70B, and 70G have been formed. This results in the manufacture of a display device 100 having a plurality of light-emitting elements, including a light-emitting element 100R having a first electrode 20, which is an anode, a first charge transport layer 30, which is a hole transport layer, the light-emitting layer 70R, the second charge transport layer 80, and the second electrode 90, a light-emitting element 100B having a light-emitting layer 70B instead of the light-emitting layer 70R, and a light-emitting element 100G having a light-emitting layer 70G instead of the light-emitting layer 70R.

[0073] Although the above describes an embodiment in which the first electrode 20 is an anode, in the manufacturing method of a light-emitting element according to an embodiment of the present disclosure, the first electrode is not limited to an anode. The light-emitting element manufactured by the manufacturing method according to an embodiment may have a forward stack structure, but is not limited thereto and may have an inverted stack 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 serving as a cathode, a first charge transport layer serving as an electron transport layer, a light-emitting layer, a second charge transport layer serving as a hole transport layer, and a second electrode serving as an anode are stacked in this order on a substrate.

[0074] The light-emitting element may be a top-emission type or a bottom-emission type. To make it a top-emission type with a forward stack structure, the anode may be formed from an electrode material that reflects visible light, and the cathode may be formed from an electrode material that transmits visible light. Conversely, to make it a bottom-emission type, the anode may be formed from an electrode material that transmits visible light, and the cathode may be formed from 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 has conductivity, and examples thereof include metal materials such as Al, Cu, Au, Mg, Li, and Ag, alloys of the above metal materials, laminates of the above metal materials and transparent metal oxides (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.), and laminates of the above alloys and the above transparent metal oxides.

[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 has conductivity, and examples thereof 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, and nanowires made of metal materials such as Al and Ag.

[0077] The first and second electrodes can be formed by a conventional electrode formation method, such as a physical vapor deposition (PVD) method such as vacuum deposition, sputtering, EB deposition, or ion plating, or a chemical vapor deposition (CVD) method. The first and second electrodes can be patterned by, but not limited to, a photolithography method or an inkjet method. The positive photosensitive composition according to an embodiment of the present disclosure can also be suitably used for patterning the first and second electrodes.

[0078] In addition, as a method for manufacturing a 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 photosensitive composition according to an embodiment of the present disclosure can also be suitably used for patterning the bank.

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

[0080] When the hole transport layer is a hole injection layer, the hole injection material may be, for example, NiO, CuI, Cu ２ O, CoO, Cr ２ O ３ , CuAlS ２ The hole injection material nanoparticles may have a thiol or amine as a ligand. These hole injection materials can be used in the formation of a hole transport layer as a dispersion.

[0081] The material used in the hole transport layer is not particularly limited as long as it is a hole transport material that can stabilize the transport of holes to the light-emitting layer. The hole transport material in the hole transport layer preferably has high hole mobility. Furthermore, the hole transport material is preferably a material (electron blocking material) that can prevent electrons that have migrated from the cathode from penetrating through the hole transport layer. This is because the recombination efficiency of holes and electrons in the light-emitting layer can be increased. The hole transport material is preferably a photosensitive hole transport material having a cationically polymerizable functional group such as an oxetane ring. Examples of the photosensitive hole transport material include N,N'-(4,4'-(cyclohexane-1,1-diyl)bis(4,1-phenylene))bis(N-(4-(6-(2-ethyloxetan-2-yloxy)hexyl)phenyl)-3,4,5-trifluoroaniline), N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyloxyphenyl)-N4,N4'-bis(4-methoxyphenyl)biphenyl-4,4'-diamine, and N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyl) Examples of the photosensitive hole transport material included in the hole transport layer include cationic polymerization using, for example, a photoacid generator. The hole transport layer may also include a product generated by exposure of the photoacid generator. Other examples of the hole transport material 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, in the form of a dispersion or a solution.

[0082] The dispersion of the hole injection material and the dispersion of the hole transport material may contain a polar solvent such as ethanol, and the polar solvent may have an SP value of less than 12.0 and a polarity term of less than 5.0, similar to the dispersion of quantum dots (QDs). According to the positive photosensitive composition and the method for manufacturing a light-emitting device according to an embodiment of the present disclosure, not only is the composition solvent-resistant to the solvent contained in the dispersion of quantum dots (QDs), but also the composition has improved polar solvent-resistant to the solvent contained in the dispersion of the hole injection material and the dispersion of the hole transport material.

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

[0084] The color of light emitted by each light-emitting layer differs depending on the central emission 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 this combination is not necessarily required.

[0085] Each light-emitting layer may include, for example, a continuous film of a metal sulfide and a plurality of quantum dots encapsulated in the continuous film. Examples of the metal sulfide include ZnS (zinc sulfide), ZnTeS, and ZnMgS. ２ , MgS, Ga ２ S ３ , ZnGa ２ S ４ , MgGa ２ S ４ The continuous film may be, for example, a sulfide semiconductor having 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 average thickness of each light-emitting layer may be 10 nm or more and 100 nm or less, and the maximum thickness of each light-emitting layer may be no more than twice the minimum 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 shell structure with a continuously changing core / shell ratio. When the quantum dots (QDs) have a core structure, a ligand is provided on the surface of the core, and when the quantum dots (QDs) have a shell structure, a ligand is provided on the surface of the shell. The core portion of the quantum dots (QDs) can be composed of, for example, Si, C, etc. in the case of a single element system, for example, Si, C, etc., or, when it is a binary element system, for example, CdSe, CdS, CdTe, InP, GaP, InN, ZnSe, ZnS, ZnTe, etc., or, when it is a ternary element system, for example, CdSeTe, GaInP, ZnSeTe, etc., or, when it is a quaternary element system, for example, AIGS, etc. In the case of a binary system, the shell portion can be composed of, for example, CdS, CdTe, CdSe, ZnS, ZnSe, ZnTe, etc., and in the case of a ternary system, the shell portion can be composed of, for example, CdSSe, CdTeSe, CdSTe, ZnSSe, ZnSTe, ZnTeSe, AIP, etc.

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

[0088] The ligand included in the quantum dots (QDs) may be an inorganic ligand or an organic ligand. When the ligand included in the quantum dots (QDs) is an organic ligand, the organic ligand may be an organic compound having a functional group such as an amine or a thiol. The quantum dots (QDs) may include the inorganic ligand described above and may also include an organic ligand. Furthermore, when the ligand included in the quantum dots (QDs) 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% higher, 50% higher, or 100% higher than the average concentration of halogen atoms at other positions.

[0089] The light-emitting layer can be formed by applying a dispersion liquid containing dispersed quantum dots to each sub-pixel separately by spin coating, inkjet printing, etc. The dispersion liquid of the quantum dots contains a solvent such as n-hexane, toluene, or phenylcyclohexane, and may contain a dispersing material such as thiol or amine.

[0090] When the light-emitting material of the light-emitting layer contains quantum dots having a shell of a metal sulfide, which is a sulfide semiconductor, as an inorganic ligand, the quantum dots may be produced in an inert gas atmosphere as follows.

[0091] First, to obtain a precursor of a sulfide semiconductor, a dispersion containing a metal source such as a metal acetate, a metal nitrate, or a metal halide salt and a sulfur source such as thiourea, N-methylthiourea, or 1,3-dimethylthiourea is prepared. The dispersion may 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 relative to the quantum dots dissolves is mixed with a nonpolar solvent in which quantum dots with carbon chains as organic ligands are dispersed, and the organic ligands of the quantum dots are substituted with halide ions. Subsequently, a dispersion of a sulfide semiconductor precursor and a dispersion of quantum dots whose organic ligands have been substituted with halide ions are mixed and stirred.

[0093] The polar solvent for producing quantum dots may include at least one of 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. The nonpolar solvent is preferably toluene, hexane, octane, octadecene, or the like, and is preferably a nonpolar solvent that is immiscible with the polar solvent for producing quantum dots.

[0094] When the polar solvent in the dispersion of the sulfide semiconductor precursor and the non-polar solvent in the dispersion of the quantum dots substituted with halide ions are separated into two phases, quantum dots having a shell of the sulfide semiconductor as an inorganic ligand can be produced in the polar solvent phase. The obtained quantum dots can be dispersed in a polar solvent and used to form a light-emitting layer, as already described.

[0095] A dispersion of quantum dots in a polar solvent is applied onto a substrate and heated to 80°C to 500°C to form a light-emitting layer containing quantum dots having a shell of sulfide semiconductor as an inorganic ligand.

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

[0097] The electron transporting material contained 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, and examples thereof include ZnO, ZnS, ZrO, MgZnO, AlZnO, and TiO.２ These nanoparticles may have a ligand such as an organic ligand or an inorganic ligand on the surface thereof. Furthermore, these compositions may be applied to sub-pixels of a plurality of light-emitting elements collectively by a spin coating method, a dip coating method, or the like, or may be applied separately to each sub-pixel by an inkjet method or the like.

[0098] Here, the dispersion of the electron transport material may contain a polar solvent such as ethanol, and the polar solvent may have an SP value of less than 12.0 and a polarity term of less than 5.0, similar to the dispersion of quantum dots (QDs). According to the positive-type photosensitive composition and the method for manufacturing a light-emitting device according to an embodiment of the present disclosure, not only is the composition highly resistant to polar solvents contained in the dispersion of quantum dots (QDs), but also the composition is highly resistant to polar solvents contained in the dispersion of the electron transport material. The electron transport material is used as a dispersion to form an electron transport layer.

[0099] The present disclosure is not limited to the above-described embodiments, 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 the present disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0100] An embodiment of the present disclosure is described below.

[0101] [1] Preparation of Resin Compositions Sample compositions were prepared using the materials shown in the [Materials] column below.

[0102] [Materials] (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 the water-soluble resin was calculated based on the following formula. PVA ratio=PVA / (PVA+PVP) PVA: molar amount of monomer units constituting PVA polymer units PVP: molar amount of monomer units constituting PVP polymer units "PVA-PVP graft copolymer A" is a graft copolymer in which the hydroxyl groups of PVA in PVA-PVP are substituted with hydrophobic groups, and "PVA-PVP graft copolymer B" is a pure PVA-PVP graft copolymer in which the hydroxyl groups of PVA are not substituted with hydrophobic groups. (Positive Photosensitizers) Positive Photosensitizer A: 1,2-diazonaphthoquinonesulfonic acid ester of 2,3,4-trihydroxybenzophenone; Positive Photosensitizer B: 1,2-diazonaphthoquinonesulfonic acid ester of 2,3,4,4'-tetrahydroxybenzophenone; Positive Photosensitizer C: 6-diazo-5,6-dihydro-5-oxo-1-naphthalenesulfonic acid ester of 4,4'-(1-{4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl}ethylidene)diphenol In all of the positive photosensitizers A to C, the conversion rate to sulfonic acid ester was approximately 100%. (Other Materials) Solvent: dimethyl sulfoxide (DMSO)

[0103] [2] Evaluation of Photoresist Layer [2-1] Evaluation of Positive Photosensitizer Five grams 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, under light-shielded conditions, this solution was mixed with positive photosensitizers A to C in a mass ratio of 17:3 (15% by mass added) or 7:3 (30% by mass added) to obtain the positive photosensitive compositions of Samples 1 to 6, with the amounts of positive photosensitizers added being as shown in Table 1.

[0104] Sample 1 was applied to a glass substrate (2.5 cm x 2.5 cm) by spin coating, and then heated and dried at 80°C for 3 minutes. As a result, a photoresist layer was formed on the glass substrate from the positive photosensitive composition of Sample 1. Subsequently, photoresist layers were formed on the glass substrate from the positive photosensitive compositions of Samples 2 to 6, and the layer of Comparative Sample 7, as individual samples, using the same procedure as Sample 1. The photoresist layers of Samples 1 to 6 and the layer of Comparative Sample 7 each had a film thickness of approximately 1 μm.

[0105] Next, the substrate was immersed in an alkaline aqueous solution (0.8% by mass TMAH) at room temperature (23°C) for 30 seconds, and then removed. ２ The photoresist layer was dried by blowing. The thickness of the photoresist layer was then measured again. Table 1 shows the evaluation results of the positive photosensitizer contained in the photosensitive composition of Samples 1 to 7, the amount added, and the amount of film thickness reduction.

[0106]

[0107] In all of Samples 1 to 6, the addition of 30% by mass suppressed film thickness reduction more effectively than the addition of 15% by mass. It was confirmed that the larger the addition amount, the more sites of diazo coupling in the non-exposed areas tended to increase. Therefore, it is considered that the polar solvent resistance can increase the film thickness remaining rate of the non-exposed areas that are desired to remain after exposure, and the developability can form a clear pattern.

[0108] [2-2] Evaluation of Ease of Peeling A positive photosensitive composition of Sample 6 was separately prepared and applied to a glass substrate (2.5 cm x 2.5 cm) by spin coating under light-shielded conditions, followed by heating and drying at 80°C for 3 minutes. Thus, a photoresist layer was formed on the glass substrate from the positive photosensitive composition of Sample 6. Similarly, a negative photoresist layer was prepared for Comparative Sample 6C by the same procedure as for the positive photosensitive composition of Sample 6, except that a negative photosensitive composition manufactured by Company T was used. The photoresist layer of the positive photosensitive composition of Sample 6 and the negative photoresist layer of Sample 6C each had a film thickness of approximately 2 μm. The composition of the negative 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 each of the positive photoresist layer formed from the positive photosensitive composition of Sample 6 and the negative photoresist layer formed from the negative photosensitive composition of Comparative Sample 6C. In the evaluation of peeling ease, the positive photoresist layer of Sample 6 was formed on the unexposed portion of the photoresist layer outside the pattern on the glass substrate under conditions without exposure, and the negative photoresist layer of Sample 6C was exposed to g-rays at an exposure dose of 240 mJ / cm. ２ The photoresist layer outside the pattern was formed on the glass substrate under the conditions of (a) to (c).

[0110] The photoresist layers of Sample 6 and Sample 6C were each immersed in DMSO at room temperature (23° C.) for 60 seconds, then removed and heated at room temperature (23° C.) under N ２ The photoresist layers were blow-dried. The thicknesses of the photoresist layers of Sample 6 and Sample 6C were then measured. The dissolution rates in water were calculated based on the difference between the thicknesses before and after immersion and the immersion time in DMSO. Table 2 shows the evaluation results of the dissolution rates in DMSO of the photoresist layers of Sample 6 and Sample 6C.

[0111]

[0112] As shown in Table 2, it was confirmed that the photoresist layer formed from the positive photosensitive composition of Sample 6, as a positive photoresist layer, had higher peeling removability with DMSO (SP value: 12.8, polarity: 7.2) than the negative photoresist layer of Sample 6, and that peeling and development after patterning could be carried out more quickly.

[0113] [2-3] Evaluation of Water-Soluble Resin A layer of a water-soluble resin contained in a photoresist layer was prepared using Samples 8 to 13 as Reference Examples and Samples 14 and 15 as Comparative Examples, and the water dissolution rate was 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] The water-soluble resin composition of Sample 9 was prepared according to the same procedure as for the water-soluble resin composition of Sample 8, except that PVA-PVP graft copolymer A-1 was changed to PVA-PVP graft copolymer A-2. Similarly, the PVA-PVP graft copolymer A-1 was changed to 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, to prepare water-soluble resin compositions of Samples 10 to 15.

[0115] The water-soluble resin compositions of Samples 8 to 15 were applied onto a glass substrate (2.5 cm×2.5 cm) by spin coating, and then heated and dried at 80° C. for 3 minutes.

[0116] Each of the water-soluble resin layers contained in the photoresist samples 8 to 15 was immersed in pure water (room temperature, approximately 23°C) for 60 seconds, then removed and heated at room temperature, 23°C, in a N ２ The samples were blow-dried. Thereafter, the film thickness of the water-soluble resin layer for photoresist was measured. The water dissolution rate was then calculated based on the difference between the film thickness before and after immersion and the time of immersion in pure water. Table 3 shows the evaluation results of the water-soluble resin, PVA ratio, and water dissolution rate contained in the water-soluble resin layer for photoresist of Samples 8 to 15.

[0117]

[0118] As shown in Table 3, the water-soluble resin layers for photoresists in Samples 8 to 13 had water dissolution rates of 50 nm / sec or higher, confirming that a higher PVA ratio is preferable from the standpoint of film thickness control. Furthermore, Samples 8 to 10, in which the PVA was partially derivatized, were able to suppress their water dissolution rates due to the influence of , despite having a lower PVA ratio than Samples 11 to 13. In contrast, the water-soluble resin layer in Sample 14, which contained polyvinyl alcohol-1, had a water dissolution rate of 30 nm / sec, which was slow, and the water-soluble resin layer in Sample 15, which contained polyvinylpyrrolidone-1, had a water dissolution rate of 1000 nm / sec, which was too fast. From these results, it is expected that copolymers, rather than water-soluble homopolymers, are preferable for the water-soluble resin used in positive-tone photosensitive compositions from the standpoints of film thickness control, i.e., developability, and polar solvent resistance.

[0119] REFERENCE SIGNS LIST 10 Substrate 20 First electrode (anode) 30 First charge transport layer (hole transport layer) 40 Bank 50, 51, 52 Photoresist layer (coating film) 70R, 70B, 70G, 70R', 70B', 70G' Light-emitting layer 80 Second charge transport layer (electron transport layer) 90 Second electrode (cathode) 100R, 100B, 100G Light-emitting element 200 Display device 300, 301, 302 Photomask

Claims

1. A manufacturing method for manufacturing a light-emitting element on a substrate, comprising: coating a composition containing a water-soluble resin, a positive photosensitive agent, and a solvent on the substrate, wherein the water-soluble resin contains a copolymer containing a vinyl alcohol monomer unit and a monomer unit having water solubility; exposing the coated composition; washing the exposed composition with a developer to develop a pattern of the composition on the substrate; forming a light-emitting layer on the substrate on which the pattern has been developed; including a step of stripping and developing the composition remaining on the substrate on which the light-emitting layer has been formed with a solvent; wherein the solvent has a δ (solubility parameter) shown by the following formula (1) of 12.0 or more; 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 bond term, and it is a manufacturing method.

2. In the above formula (1), the solvent has a δ Ｐ of 5.0 or more. The production method according to claim 1.

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