Radiation-sensitive composition processing method

Abstract

Provided is a processing method for a radiation-sensitive composition that can impart high transmittance to a radiation-sensitive composition even when an LED light source is used, and that can suppress the generation of bubbles. The processing method for a radiation-sensitive composition of the present invention is characterized by a radiation-sensitive composition having a resin (A) that is a copolymer of a radical polymerizable compound (a) having an acid group, a radical polymerizable compound (b) having an epoxy group, and another radical polymerizable compound (c), and a radiation-sensitive acid-generating compound (B), wherein the method includes the following process (α): irradiating the radiation-sensitive composition with ultraviolet rays having a main peak wavelength in a range of 375 nm or more and 395 nm or less from an LED element, and increasing the transmittance of the radiation-sensitive composition.

Description

Technical Field

[0001] This invention relates to a method for processing radiation-sensitive compositions, and more specifically, to a bleaching treatment method for improving the transmittance of radiation-sensitive compositions. Background Technology

[0002] In display devices such as liquid crystal panels and organic EL panels, tiny semiconductor elements are disposed corresponding to each pixel. As an insulating material (resist material) within these elements, compositions that display the property of sensing light (radiation sensitivity) are widely used.

[0003] For example, it is known that in the manufacturing process of display devices, the light transmittance and durability (heat resistance) of a pattern are improved by coating it with a radiation-sensitive composition, pre-baking it, and then irradiating the exposed and developed pattern with ultraviolet light. Sometimes, this process of improving the transmittance of visible light by irradiating the patterned film with ultraviolet light is called a "bleaching process." This process is caused by using ultraviolet light to decompose the photosensitive material contained in the radiation-sensitive composition.

[0004] For example, Patent Document 1 describes a bleaching treatment of an anti-etching pattern by irradiating it with i-rays, i.e., ultraviolet light with a wavelength of 365 nm.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2017-037169 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The light source used for bleaching is generally a high-pressure mercury lamp. The aforementioned patent document 1 also mentions "i-rays," therefore it is estimated to refer to the mercury spectrum. Although not explicitly stated, it can be understood that a high-pressure mercury lamp was intended to be used.

[0010] In response, with the technological advancements in solid-state light sources in recent years, research is underway on bleaching processes using UV-LEDs.

[0011] However, through in-depth research by the inventors, it has been found that when using an LED light source in the bleaching process, problems such as failing to obtain the desired transmittance (bleaching ability) and foaming inside the radiation-sensitive composition are easily generated.

[0012] In view of the above-mentioned problems, the present invention aims to provide a method for processing a radiation-sensitive composition that can impart high transmittance to the radiation-sensitive composition and thus suppress the generation of bubbles, even when using an LED light source.

[0013] Methods for solving problems

[0014] This invention relates to a method for processing a radiation-sensitive composition, characterized in that the radiation-sensitive composition comprises:

[0015] A resin (A) soluble in alkaline aqueous solution, which is a copolymer of a free radical polymerizable compound (a) having an acid group, a free radical polymerizable compound (b) having an epoxy group, and other free radical polymerizable compounds (c).

[0016] Radiation-sensitive acid-producing compounds (B);

[0017] The method includes the following steps (α):

[0018] By irradiating the radiation-sensitive composition with ultraviolet light of a main peak wavelength range of 375 nm or higher and 395 nm from an LED element, the transmittance of the radiation-sensitive composition is increased.

[0019] In the case of bleaching films containing radiation-sensitive compositions, mercury lamps have conventionally been used, as explained in the section on "Problems to be Solved by the Invention". This is because it is known from experience that radiation-sensitive acid-producing compounds exhibit high photosensitivity to one of the peak wavelengths of light emitted from a mercury lamp, namely 365 nm (i-rays).

[0020] Based on the above insights, the inventors first prepared an LED element with a dominant peak wavelength around 365 nm, and bleached it by irradiating a treatment object film (hereinafter, sometimes appropriately referred to as "object film") made of a radiation-sensitive composition with ultraviolet light emitted from the LED element. It was then confirmed that the transmittance of the object film after this treatment was lower than expected, and the desired transmission performance was not achieved.

[0021] It should be noted that the statement above that the main peak wavelength is "around 365nm" is because even if the LED element is obtained as a main peak wavelength of 365nm, there are sometimes individual differences between the elements, and the main peak wavelength will have a manufacturing error of about ±10nm.

[0022] Furthermore, several air bubbles were confirmed to exist within the processed object film. As described above, the object film, comprising a radiation-sensitive composition, functions as an insulating film in liquid crystal panels, organic EL panels, and the like. Therefore, if air bubbles are visually identifiable from the light extraction side, it will affect the display performance of the device.

[0023] To address this, the inventors experimented with preparing an LED element whose wavelength was intentionally shifted to a wavelength longer than i-rays (365 nm), emitting light with a main peak wavelength of 375 nm or higher and 395 nm or lower, and irradiating the aforementioned target film with ultraviolet light from the LED element. Surprisingly, it was found that compared to irradiating with ultraviolet light from an LED element with a main peak wavelength near 365 nm, the transmittance was increased, and the amount of bubbles generated within the film was significantly reduced. Given the previous understanding that radiation-sensitive acid-producing compounds, represented by quinone diazide compounds, exhibit high photosensitivity at 365 nm, this fact is a truly surprising effect.

[0024] In this specification, "dominant peak wavelength" refers to the wavelength with the highest light intensity in the spectrum.

[0025] The ultraviolet light can be ultraviolet light with a half-width of less than 20 nm.

[0026] By using an LED element that emits ultraviolet light with a half-width of 20 nm, the intensity of the 365 nm component of the ultraviolet light can be sufficiently reduced relative to the intensity of the main peak wavelength. This allows for both increased transmittance and suppression of bubble formation.

[0027] The light intensity at a wavelength of 365 nm of the ultraviolet light can be less than 10% of the light intensity at the main peak wavelength.

[0028] The process (α) may be a process of irradiating the radiation-sensitive composition with ultraviolet light from the LED element through a filter of light with a cutoff wavelength of less than 365 nm.

[0029] The radiation-sensitive acid-producing compound (B) can be a 1,2-quinone diazide compound.

[0030] The proportion of the radiation-sensitive acid-producing compound (B) in the radiation-sensitive composition may be 15-30 parts by weight relative to 100 parts by weight of the resin (A).

[0031] The other free radical polymerizable compound (c) may be a structural unit derived from at least one monomer selected from (meth)acrylates having an alicyclic structure, (meth)acrylates having an aromatic ring structure, aromatic vinyl compounds, N-substituted maleimide compounds, and vinyl compounds having a heterocyclic structure.

[0032] By including cyclic structures such as (meth)acrylates with alicyclic structures, (meth)acrylates with aromatic ring structures, aromatic vinyl compounds, N-substituted maleimide compounds, or vinyl compounds with heterocyclic structures in the compounds constituting the resin, the foaming inhibition effect under ultraviolet irradiation can be improved.

[0033] The resin (A) may contain structural units with crosslinking groups. This configuration further enhances its ability to suppress foaming under ultraviolet irradiation.

[0034] Furthermore, the processing method for the above-mentioned radiation-sensitive composition can be characterized by:

[0035] The process of forming a film on the basement membrane (β1),

[0036] In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and

[0037] After the step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development.

[0038] The process (α) is performed after the process (β3).

[0039] The above method can improve, for example, the transmittance of an insulating film formed on a display device after pattern formation.

[0040] Invention Effects

[0041] The method of the present invention enables high transmittance of a film containing a radiation-sensitive composition and suppresses the generation of bubbles within the film, even when using an LED light source. Attached Figure Description

[0042] Figure 1 This is a schematic diagram illustrating one step of a method for processing the radiation-sensitive composition of the present invention.

[0043] Figure 2 This is a diagram showing an example of the spectrum of ultraviolet light emitted from an LED element.

[0044] Figure 3It is a graph created by overlaying the spectra of ultraviolet rays with main peak wavelengths of 365nm, 385nm, and 405nm.

[0045] Figure 4 This is another diagram schematically illustrating one step of a method for processing the radiation-sensitive composition of the present invention.

[0046] [Symbol Explanation]

[0047] 1: Object membrane

[0048] 2: Layer (the lower layer of the object film)

[0049] 3: Light source

[0050] 4: LED components

[0051] 5: Filter

[0052] L1: Ultraviolet light Detailed Implementation

[0053] Figure 1 This is a schematic diagram illustrating one step of the processing method for the radiation-sensitive composition of the present invention. However, Figure 1 The diagram is for illustrative purposes only, and the actual dimensions may not match those shown in the diagram.

[0054] A membrane to be processed (hereinafter referred to as "object membrane 1") is laminated on top of layer 2 and a patterning process is performed. Object membrane 1 is composed of a material exhibiting radiation sensitivity (radiation-sensitive composition). A detailed description of the material will be given later. Layer 2 corresponds to "base membrane".

[0055] The target film 1 is irradiated with ultraviolet L1, which has a main peak wavelength of 375 nm or higher and 395 nm or lower (corresponding to process (α)), from a light source 3 equipped with LED element 4. Figure 2 An example representing the spectrum of ultraviolet L1. Figure 2 The spectrum shown corresponds to the case where LED element 4 is an element emitting ultraviolet light L1 with a main peak wavelength of 385 nm. Figure 2 In the spectrum shown, the half-width dλ is 13 nm. Preferably, the half-width dλ is less than 20 nm.

[0056] Such an LED element 4 is realized, for example, by comprising an active layer having a well layer composed of InGaN or AlInGaN and a barrier layer composed of In with a lower concentration than GaN or the well layer.

[0057] By irradiating the target film 1 with ultraviolet L1 with a main peak wavelength of 375 nm or higher and 395 nm or lower, the transmittance of the target film 1 is improved, and the generation of bubbles within the target film 1 is suppressed. This will be described later with reference to the embodiments.

[0058] Next, the material of the object membrane 1 will be described.

[0059] The target membrane 1 comprises a radiation-sensitive composition. This radiation-sensitive composition contains a resin (A) and a radiation-sensitive acid-producing compound (B), and may contain other complexing agents (C) as needed.

[0060] Resin (A)

[0061] Resin (A) is composed of a material having alkali-soluble groups and preferably exhibiting properties that can be cured by heating. Resin (A) is obtained by free radical copolymerization in a solvent of a free radical polymerizable compound (a) having acid groups and a free radical polymerizable compound (b) having epoxy groups, along with other free radical polymerizable compounds (c).

[0062] A specific example of a free radical polymerizable compound (a) having an acid group:

[0063] Examples of unsaturated monocarboxylic acids that constitute structural units with carboxyl groups include (meth)acrylic acid, crotonic acid, and 4-vinylbenzoic acid; and unsaturated dicarboxylic acids include maleic acid, fumaric acid, citraconic acid, succinic acid, and itaconic acid.

[0064] Examples of monomers that constitute structural units having sulfonic acid groups include vinyl sulfonic acid, (meth)allyl sulfonic acid, styrene sulfonic acid, and (meth)acryloyloxyethyl sulfonic acid.

[0065] Examples of monomers that constitute structural units with phenolic hydroxyl groups include 4-hydroxystyrene, o-isopropenylphenol, m-isopropenylphenol, p-isopropenylphenol, and hydroxyphenyl methacrylate.

[0066] Alternatively, maleimide can be used as a monomer.

[0067] Examples of free radical polymerizable compounds (b) with epoxy groups include glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, methyl (meth)acrylate, 2-(3,4-epoxycyclohexyl)ethyl (meth)acrylate, and 3,4-epoxytricyclo[5.2.1.0] 2,6Decyl (meth)acrylate, (3-methyloxetane-3-yl)meth(meth)acrylate, (3-ethyloxetane-3-yl)(meth)acrylate, (oxetane-3-yl)meth(meth)acrylate, (3-ethyloxetane-3-yl)meth(meth)acrylate, etc. It should be noted that in this specification, ethylene oxide and butyl oxide are referred to as "epoxy groups".

[0068] When the above resin (A) (hereinafter referred to as "copolymer (I)") is obtained, in the free radical polymerization of the above-mentioned free radical polymerizable compound (a) having acid groups and free radical polymerizable compound (b) having epoxy groups, sometimes the free radical polymerizable compound having epoxy groups and acid groups reacts in the polymerization reaction, causing crosslinking, and the polymerization system gels.

[0069] Therefore, in order to obtain copolymer (I), it is preferable to use another radical polymerizable compound (c) as a third component to suppress the reaction with radical polymerizable compounds having epoxy and acid groups. Examples of such other radical polymerizable compounds (c) include alkyl (meth)acrylates, cycloalkyl (meth)acrylates, aromatic (meth)acrylates, aromatic vinyl compounds, N-substituted maleimide compounds, heterocyclic vinyl compounds, conjugated diene compounds, nitrogen-containing vinyl compounds, and unsaturated dialkyl dicarboxylic acid ester compounds.

[0070] As a specific example of other free radical polymerizable compounds (c):

[0071] Examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and stearyl methacrylate.

[0072] Examples of (meth)acrylates with an alicyclic structure include cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, and tricyclohexyl (meth)acrylate [5.2.1.0]. 2,5 Decane-8-yloxyethyl ester, isobornyl acrylate, etc.

[0073] Examples of (meth)acrylates having an aromatic ring structure include phenyl (meth)acrylate and benzyl (meth)acrylate.

[0074] Examples of aromatic vinyl compounds include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 5-tert-butyl-2-methylstyrene, divinylbenzene, trivinylbenzene, tert-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-dimethylaminoethylstyrene, N,N-dimethylaminomethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-tert-butylstyrene, 3-tert-butylstyrene, 4-tert-butylstyrene, diphenylethylene, vinylnaphthalene, vinylpyridine, etc.

[0075] Examples of N-substituted maleimide compounds include N-cyclohexylmaleimide, N-cyclopentylmaleimide, N-(2-methylcyclohexyl)maleimide, N-(4-methylcyclohexyl)maleimide, N-(4-ethylcyclohexyl)maleimide, N-(2,6-dimethylcyclohexyl)maleimide, N-norbornylmaleimide, N-tricyclodecylmaleimide, N-adamantylmaleimide, N-phenylmaleimide, N-(2-methylphenyl)maleimide, N-(4-methylphenyl)maleimide, N-(4-ethylphenyl)maleimide, N-(2,6-dimethylphenyl)maleimide, N-benzylmaleimide, and N-naphthylmaleimide.

[0076] Examples of vinyl compounds with heterocyclic structures include tetrahydrofurfuryl (meth)acrylate, tetrahydropyran acrylate, 5-ethyl-1,3-dioxane-5-yl methyl acrylate, 5-methyl-1,3-dioxane-5-yl methyl acrylate, (2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl acrylate, 2-(meth)acryloyloxymethyl-1,4,6-trioxaspiro[4,6]undecane, (γ-butyrolactone-2-yl) acrylate, (meth)acrylic acid glycerol carbonate, (γ-lactam-2-yl) acrylate, and N-(meth)acryloyloxyethyl hexahydrophthalimide.

[0077] Examples of conjugated diene compounds include 1,3-butadiene and isoprene.

[0078] Examples of nitrogen-containing vinyl compounds include (meth)acrylonitrile and (meth)acrylamide;

[0079] Examples of unsaturated dialkyl dicarboxylic acid esters include diethyl itaconic acid.

[0080] In addition to the above, other monomers include vinyl chloride, vinylidene chloride, vinyl acetate, etc.

[0081] From the viewpoint of adjusting the glass transition temperature of the polymer composition to suppress melt flow during thermosetting, the other free radical polymerizable compound (c) is preferably derived from the structural unit of at least one monomer selected from alkyl methacrylates, (meth)acrylates having an alicyclic structure, (meth)acrylates having an aromatic ring structure, aromatic vinyl compounds, N-substituted maleimide compounds, and vinyl compounds having a heterocyclic structure.

[0082] Furthermore, the copolymerization ratio of the free radical polymerizable compound (a) with acid groups in copolymer (I) is preferably 5-40% by mass, and particularly preferably 10-30% by mass. If it is less than 5% by mass, the resulting copolymer is not easily soluble in alkaline aqueous solution, thus easily producing development residue and making it difficult to form a sufficient pattern. Conversely, if it exceeds 40% by mass, the resulting copolymer becomes too soluble in alkaline aqueous solution, making it difficult to prevent dissolution of the irradiated part, i.e., film reduction (film thickness loss) during development.

[0083] The copolymerization ratio of the epoxy-based free radical polymerizable compound (b) in copolymer (I) is preferably 10-70% by mass, particularly preferably 20-50% by mass. If it is less than 10% by mass, the reaction to generate acid by irradiation with radiation of the acid-based free radical polymerizable compound (a) or the radiation-sensitive acid-producing compound (B) is difficult to carry out sufficiently, and the heat resistance of the pattern obtained from the composition becomes insufficient. In addition, if it exceeds 70% by mass, the storage stability of copolymer (I) is prone to problems.

[0084] The copolymerization ratio of other free radical polymerizable compounds (c) of copolymer (I) is preferably 10 to 70% by mass, particularly preferably 30 to 50% by mass. If it is less than 10% by mass, gelation is likely to occur during the polymerization reaction. In addition, if it exceeds 70% by mass, the amount of free radical polymerizable compounds (b) with epoxy groups and free radical polymerizable compounds (a) with acid groups becomes relatively small, so the solubility of the resin in alkaline aqueous solutions may sometimes decrease, or the heat resistance of the pattern obtained from the composition may become insufficient.

[0085] Examples of solvents used in polymerizing copolymer (I) include alcohols such as methanol and ethanol; ethers such as tetrahydrofuran; glycol ethers such as ethylene glycol monomethyl ether; cellosol esters such as methyl cellosol acetate; propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate and propylene glycol propyl ether acetate; and others such as aromatic hydrocarbons, ketones, and esters.

[0086] As polymerization catalysts in free radical polymerization, common free radical polymerization initiators can be used, such as azo compounds like 2,2'-azobisisobutyronitrile, 2,2'-azobis-(2,4-dimethylpentanonitrile), and 2,2'-azobis-(4-methoxy-2,4-dimethylpentanonitrile); organic peroxides such as benzoyl peroxide, lauroyl peroxide, tert-butyl peroxypentanoate, and 1,1-bis-(tert-butylperoxy)cyclohexane; and hydrogen peroxide. When peroxides are used as free radical polymerization initiators, redox initiators can also be prepared by combining reducing agents.

[0087] The molecular weight and distribution of the copolymer (I) are not particularly limited as long as the solution of the radiation-sensitive composition forming the target film 1 can be uniformly coated.

[0088] Radiation-Sensitive Acid-Generating Compounds (B)

[0089] Radiation-sensitive acid-producing compounds (B) are compounds that produce acids upon exposure to light. As an example, a radiation-sensitive acid-producing compound is a quinone diazide compound (B1). Quinone diazide compounds (B1) are esters of compounds having one or more phenolic hydroxyl groups with 1,2-naphthoquinone diazide-4-sulfonic acid or 1,2-naphthoquinone diazide-5-sulfonic acid.

[0090] More specifically, examples of quinone diazide compounds (B1) include 1,2-benzoquinone diazidesulfonate, 1,2-naphthoquinone diazidesulfonate, 1,2-benzoquinone diazidesulfonamide, and 1,2-naphthoquinone diazidesulfonamide.

[0091] Among them, the quinone diazide compound (B1) is preferably a compound with good transparency in the visible light region of 400-800 nm after irradiation, such as 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 3'-methoxy-2,3,4,4'-tetrahydroxybenzophenone, 2,2',5,5'-tetramethyl-2',4,4'-trihydroxytriphenylmethane, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol and 2,4,4-trimethyl-2',4',7-trihydroxy-2-phenylflavans, etc., as well as 1,2-benzoquinone diazide-4-sulfonate, 1,2-naphthoquinone diazide-4-sulfonate or 1,2-naphthoquinone diazide-5-sulfonate.

[0092] Quinone diazide compounds (B1) can be used alone or in combination with two or more.

[0093] It should be noted that the radiation-sensitive acid-producing compound (B) is any compound that produces acid through irradiation with light, and is not limited to quinone diazide compounds (B1), but can also be other acid-producing agents (B2). Examples of acid-producing agents (B2) include onium salt compounds, halogen-containing compounds, sulfone compounds, sulfonic acid compounds, sulfonylimide compounds, and diazomethane compounds.

[0094] The amount of radiation-sensitive acid-producing compound (B) added relative to 100 parts by weight of resin (A) is preferably 5 to 100 parts by weight, more preferably 10 to 50 parts by weight, and particularly preferably 15 to 30 parts by weight. If it is less than 5 parts by weight, the amount of acid generated by light absorption is reduced, so it is impossible to produce a difference in solubility in alkaline aqueous solution before and after light irradiation, making pattern formation difficult. In addition, even in the reaction with the epoxy groups of copolymer (I), the amount of acid involved is reduced, so the heat resistance of the pattern obtained from the composition may be poor. Furthermore, if it exceeds 100 parts by weight, most of the added radiation-sensitive acid-producing compound remains in its original form after short-term radiation irradiation, so sometimes the insolubility in alkaline aqueous solution is too high, making development difficult.

[0095] In particular, by adding the amount of radiation-sensitive acid-producing compound (B) in the range of 15 to 30 parts by weight relative to 100 parts by weight of resin (A), the effect of suppressing the amount of bubbles generated after process (α) is improved.

[0096] Other compounding agents (C)

[0097] From the viewpoint of improving the hardness and heat resistance of the target film 1, it is also possible to use (meth)acrylic acid compounds, epoxy compounds, etc. as shown below.

[0098] (Meth)acrylic compounds are used to further improve the hardness, heat resistance, and other properties of the coating film formed by the self-polymerization of (meth)acrylic compounds during final heating. Examples of (meth)acrylic compounds include monofunctional (meth)acrylates, difunctional (meth)acrylates, and (meth)acrylates with three or more functions. Epoxy compounds are used to adjust the reaction point of the aforementioned copolymer (I) and the acid generated from the radiation-sensitive acid-producing compound during final heating.

[0099] Examples of epoxy compounds include bisphenol A type epoxy resins, phenolic varnish type epoxy resins, cresol phenolic varnish type epoxy resins, cyclic aliphatic epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, and heterocyclic epoxy resins. Among these, phenolic varnish type epoxy resins, cresol phenolic varnish type epoxy resins, cyclic aliphatic epoxy resins, and glycidyl ester type epoxy resins are preferred, considering that they are less prone to coloring after heat treatment.

[0100] As a complexing agent (C), it may also contain crosslinking compounds. Crosslinking compounds include, for example, compounds with crosslinking groups such as ethylene oxide (1,2-epoxy structure), butyl oxide (1,3-epoxy structure), hydroxymethyl, vinyl, (meth)acryloyl, cyclic carbonate, etc.

[0101] Among the crosslinking groups, ethylene oxide (epoxy group), epoxybutyl group, hydroxymethyl group and combinations thereof are preferred, ethylene oxide and epoxybutyl group are more preferred, and ethylene oxide is even more preferred.

[0102] As a complexing agent (C), a surfactant may be included. For example, fluorinated surfactants, silicone surfactants, and other surfactants may be used.

[0103] The radiation-sensitive composition contained in the target membrane 1 can be readily prepared by uniformly mixing the above-mentioned components. During mixing, the components are typically dissolved in a suitable solvent and supplied for use in solution form. As the solvent used, a solvent that uniformly dissolves the copolymer (I) and the radiation-sensitive acid-producing compound (B) without reacting with the components can be used.

[0104] As solvents, for example, alcohols such as methanol and ethanol; ethers such as tetrahydrofuran; glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, and diethylene glycol methyl ethyl ether; propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate and propylene glycol propyl ether acetate; toluene, xylene... Aromatic hydrocarbons such as benzene; ketones such as methyl ethyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxylate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl acetate, and butyl acetate.

[0105] In addition, high-boiling-point solvents such as N-methylformamide, N,N-dimethylformamide, N-methylformaniline, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, benzyl ethyl ether, dihexyl ether, acetone-based acetone, isophorone, hexanoic acid, octanoic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, and phenyl cellosolve acetate can also be added.

[0106] Among these solvents, based on solubility, reactivity with each component, and ease of film formation, glycol ethers such as ethylene glycol monoethyl ether are preferred; glycol alkyl ether acetates such as ethyl cellosolve acetate are preferred; esters such as ethyl 2-hydroxypropionate are preferred; diethylene glycols such as diethylene glycol monomethyl ether and diethylene glycol methyl ethyl ether, and propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate are preferred.

[0107] Alternatively, when preparing the composition solution, solutions of copolymer (I), radiation-sensitive acid-producing compounds, and other complexing agents can be prepared separately in advance, and these solutions can be mixed in a specified ratio just before use. The composition solution prepared as described above can also be used after filtration using a membrane filter with a pore size of 0.2 μm.

[0108] When preparing the target film 1, the above-mentioned composition solution is applied to a specified substrate surface. Figure 1 The solvent is removed by heating the upper surface of layer 2 (the middle layer), thereby forming the desired coating film. There are no particular limitations on the coating method on the substrate surface; for example, various methods such as spraying, roller coating, and spin coating can be used.

[0109] The heating conditions for the coating of the radiation-sensitive composition vary depending on the type and proportion of each component, but are typically around 70–90°C for 5–15 minutes. Next, the resulting coating is irradiated with ultraviolet light through a mask with a predetermined pattern, followed by development with a developing solution to remove unwanted areas and form the pattern. Figure 1 The image shows the coating film (object film 1) after pattern formation.

[0110] As a developer, aqueous solutions of bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo(5.4.0)-7-undecene, and 1,5-diazabicyclo(4.3.0)-5-nonene can also be used. Alternatively, an aqueous solution containing an appropriate amount of a water-soluble organic solvent or surfactant such as methanol or ethanol can be added to the above-mentioned base solutions as a developer.

[0111] The development time is typically 30–180 seconds. The development method can be any of the following: liquid coating method, immersion method, etc. After development, a 30–90 second water rinse is performed, followed by air drying using compressed air or compressed nitrogen. This removes unwanted areas and forms a pattern. Then, for example, ultraviolet light is used to irradiate the unexposed areas of the pattern, causing the acid-producing compounds to transform into acid. Furthermore, using heating devices such as hot plates or ovens, a heating treatment is performed at a specified temperature, such as 150–250°C, for a specified time—for example, 5–30 minutes on a hot plate or 30–90 minutes in an oven—to obtain an object film with excellent heat resistance, transparency, and hardness.

[0112] [Example]

[0113] Next, embodiments will be provided to illustrate the invention in more detail, but the invention is not limited to these embodiments in any way. Furthermore, unless otherwise specified, "parts" hereafter refers to "parts by mass".

[0114] [Synthesis Example 1] (Synthesis of copolymer (I-1))

[0115] Ten parts of 2,2'-azobis(2,4-dimethylpentanonitrile) and 200 parts of propylene glycol monomethyl ether acetate (PGMEA) were added to a flask equipped with a cooling tube and a stirrer. Next, 15 parts of methacrylic acid, 20 parts of glycidyl methacrylate, 15 parts of 3,4-epoxycyclohexyl methacrylate, and 50 parts of styrene were added. After nitrogen purging, the solution temperature was raised to 70°C while slowly stirring, and maintained at this temperature for 5 hours for polymerization, thereby obtaining a polymer solution containing copolymer (I-1) as an alkali-soluble resin. The obtained polymer was purified by reprecipitation in hexane, filtration, and vacuum drying, dissolving copolymer (I-1) in PGMEA to prepare a solution with a polymer concentration of 30% by mass. The copolymer (I-1) has a weight-average molecular weight (Mw) of 10,000 and a weight-average molecular weight (Mw) / number-average molecular weight (Mn) ratio of 2.3.

[0116] [Synthetic Examples 2-4] (Synthesis of copolymers (I-2) to (I-4))

[0117] Except for the components of the types and proportions (parts by mass) shown in Table 1 below, polymer solutions containing copolymers (I-2) to (I-4) were obtained by the same method as in Synthesis Example 1. In Table 1, "-" indicates that the corresponding component was not used.

[0118] Table 1

[0119]

[0120] The meanings of the symbols in Table 1 are as follows.

[0121] MA: Methacrylic acid

[0122] GMA: Glycidyl methacrylate

[0123] ST: Styrene

[0124] M-100: 3,4-Epoxycyclohexyl methyl methacrylate (manufactured by Daicel, Cyclomer M100 Co., Ltd.)

[0125] DCM: Dicyclopentyl methacrylate

[0126] CHMI: N-Cyclohexylmaleimide

[0127] PMI: N-Phenylonmaleimide

[0128] PIPE: p-Isopropylenephenol

[0129] OXMA: Methyl methacrylate (3-ethyloxetane-3-yl)

[0130] [Ingredients of the radiation-sensitive composition]

[0131] The following shows the copolymer (I) (resin (A)), the radiation-sensitive acid-producing compound (B), and the organic solvent (C) used as other complexing agents in the preparation of the radiation-sensitive compositions of the Examples and Comparative Examples.

[0132] <Copolymer (I)>

[0133] Copolymers I-1 to I-4: Copolymers (I-1) to (I-4) synthesized in Synthesis Examples 1-4

[0134] <Radiation-Sensitive Acid-Generating Compound (B)>

[0135] B-1: A condensation product of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol (1.0 mol) and 1,2-naphthoquinone diazido-5-sulfonyl chloride (2.0 mol).

[0136] B-2: A condensation product of 1,1,1-tris(p-hydroxyphenyl)ethane (1.0 mol) and 1,2-naphthoquinone diazido-5-sulfonyl chloride (2.0 mol).

[0137] <Organic Solvents (C)>

[0138] C-1: Diethylene glycol methyl ethyl ether (EDM)

[0139] C-2: Propylene glycol monomethyl ether acetate (PGMEA)

[0140] [evaluate]

[0141] The target membrane 1 was manufactured using the radiation-sensitive compositions of the examples and comparative examples, and the following items were evaluated.

[0142] <Example 1>

[0143] In a polymer solution containing copolymer (I-1) at a concentration of 30% by mass, 30 parts of a radiosensitive acid-producing compound (B-1) were mixed based on 100 parts of copolymer (I-1). Furthermore, the resulting mixture was dissolved in an organic solvent (C-1) to achieve a concentration of 30% by mass for all components except the solvent, and then filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiosensitive composition.

[0144] <Examples 2-9, Comparative Examples 1-4>

[0145] The radiation-sensitive compositions of Examples 2-9 and Comparative Examples 1-4 were prepared using the components of the types shown in Table 2 below, except that the procedure was the same as in Example 1.

[0146] <Bubble Evaluation>

[0147] After applying the radiation-sensitive compositions of the examples and comparative examples shown in Table 2 below to a silicon substrate using a spin coater, a film with a thickness of 6.0 μm was formed by pre-baking on a hot plate at 90°C for 2 minutes. Next, the film was developed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23°C for 60 seconds via liquid-encapsulation method.

[0148] Next, the substrate was rinsed with ultrapure water for 1 minute and then dried to fabricate a foaming evaluation substrate simulating the target membrane 1. For this evaluation substrate, a flow rate of 2000 mW / cm² was used. 2 Illuminance, 600mJ / cm 2 The exposure is from the light source 3 equipped with LED element 4 irradiating ultraviolet L1 of the wavelength recorded in Table 2.

[0149] After irradiation with ultraviolet L1, the bubbles on the coating surface are visually evaluated at six levels based on the following criteria.

[0150] (Evaluation Criteria)

[0151] 0. Bubble generation could not be confirmed.

[0152] 1. Bubbles were locally detected at the end of the coating.

[0153] 2. Check for air bubbles on the entire surface of the coating end.

[0154] 3. Bubbles were locally detected in the center of the coating.

[0155] 4. Check for air bubbles in the center of the coating.

[0156] 5. Bubbles were found all over the center of the coating, and a portion of the coating was defective.

[0157] It should be noted that, as mentioned above, since the coating is applied by spin coating, the ends of the evaluation substrate are slightly thicker than the center. Since thicker films are more prone to bubble formation, the presence of bubbles in the thinner areas, i.e., the center of the coating, indicates a situation where bubbles are more likely to form.

[0158] <Evaluation of Transmittance>

[0159] After applying the radiation-sensitive compositions of the examples and comparative examples shown in Table 2 below to a glass substrate (Corning Corporation's "Corning 7059") using a spin coater, the coatings were pre-baked on a hot plate at 90°C for 2 minutes to form a film with a thickness of 3.0 μm or 6.0 μm. Next, the coatings were developed using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23°C for 60 seconds via liquid-encapsulation.

[0160] Next, the substrate was rinsed with ultrapure water for 1 minute and then dried to form an evaluation substrate that simulates the object film 1. The evaluation substrate was subjected to a curing process at 2000 mW / cm². 2 Illuminance, 600mJ / cm 2 The exposure is achieved by irradiating the light source 3 equipped with LED element 4 with ultraviolet light L1 of the wavelength listed in Table 2. Then, it is heated at 230°C for 30 minutes. This heating is performed to promote the cross-linking reaction (curing) of the cross-linking components present in the target film 1.

[0161] For the evaluation substrate, the transmittance in the wavelength range of 400nm to 800nm ​​is measured using a spectrophotometer (Hitachi's "150-20 type double beam"). For each glass substrate used for evaluation, the lowest transmittance in the wavelength range of 400nm to 800nm ​​is evaluated (also known as the minimum transmittance).

[0162] In addition, the same evaluation was performed on the evaluation substrate, which was prepared in the same manner and had a coating thickness of 6.0 μm, using the radiation-sensitive compositions of the examples and comparative examples shown in Table 2 below.

[0163] It should be noted that the transmittance of the evaluation substrate manufactured with a coating thickness of 3.0 μm before ultraviolet L1 irradiation was 70%, and the transmittance of the evaluation substrate manufactured with a coating thickness of 6.0 μm before ultraviolet L1 irradiation was 52%.

[0164] The evaluation results of the radiation-sensitive compositions of Examples 1 to 9 and Comparative Examples 1 to 4, and the target membrane 1 generated using the compositions are shown in Table 2 below.

[0165] Table 2

[0166]

[0167] Figure 3 This is a graph created by overlaying the spectra of ultraviolet L1 emitted from the light source 3 used in each embodiment or comparative example, with peak wavelengths of 365nm, 385nm, and 405nm. In the embodiments, the evaluation substrate is irradiated with ultraviolet L1 from the light source 3 equipped with an LED element 4 having a peak wavelength of 385nm. In the comparative examples, unlike the light source 3 used in the embodiments, a light source 3 equipped with an LED element 4 having a peak wavelength of 365nm or a light source 3 equipped with an LED element 4 having a peak wavelength of 405nm is prepared, and the evaluation substrate is irradiated with ultraviolet L1 from each light source 3.

[0168] According to Table 2, when comparing the radiation-sensitive compositions formed with the same material composition in Examples 1, Comparative Examples 1 and 2, the results showed that, compared with the cases where ultraviolet L1 with a main peak wavelength of 365 nm or 405 nm was irradiated (Comparative Examples 1 and 2), the case where ultraviolet L1 with a main peak wavelength of 385 nm was irradiated (Example 1) had high transmittance regardless of the film thickness of the target film 1 and suppressed foaming within the film.

[0169] Similarly, according to Table 2, when comparing the radiation-sensitive compositions formed with the same material composition in Examples 3, 3, and 4, the results showed that, compared with the cases where ultraviolet L1 with a main peak wavelength of 365 nm or 405 nm was irradiated (Comparative Examples 1 and 2), the case where ultraviolet L1 with a main peak wavelength of 385 nm was irradiated (Example 1) had high transmittance regardless of the thickness of the target film 1 and suppressed foaming within the film.

[0170] Furthermore, it is known that in any of the Examples 1-9 manufactured by appropriately changing the composition of the radiation-sensitive composition, irradiation with ultraviolet L1 with a main peak wavelength of 385 nm resulted in high transmittance and suppressed foaming within the film, regardless of the thickness of the target film 1.

[0171] It is believed that the generation of bubbles in the object film 1 by irradiating it with ultraviolet light L1, which contains a radiation-sensitive composition, is due to the generation of nitrogen gas, for example, by the reaction described in equation (1) below. Equation (1) below represents the reaction when a naphthoquinone diazide compound constituting a radiation-sensitive acid-producing compound (B) is irradiated with ultraviolet light L1 (denoted as hν in equation (1) below).

[0172] [Chemical Formula Number 1]

[0173]

[0174] The reaction described in equation (1) readily occurs when the naphthoquinone diazide compound is irradiated with ultraviolet light of a wavelength exhibiting high photosensitivity. That is, in this invention, it is believed that by irradiating the target film 1 containing the radiosensitive acid-producing compound (B) with ultraviolet light L1 of a wavelength intentionally reduced to slightly decrease photosensitivity, the reaction in equation (1) proceeds more slowly, thereby reducing the rate of nitrogen production. Furthermore, the results in Table 2 confirm that even when irradiated with ultraviolet light L1 of a slightly reduced photosensitivity wavelength, specifically with a main peak wavelength of 385 nm, the transmittance of the target film 1 is improved.

[0175] It should be noted that, as explained in the section on "Means for Solving the Problem," individual variations in the LED element 4 within ±10 nm of its main peak wavelength may exist due to differences in manufacturing precision and the environment in which it is used. In view of the above, it is understood that by irradiating the target film 1 with ultraviolet light L1 in the range of main peak wavelength between 375 nm and 395 nm from the LED element 4, similar to the embodiments, it is possible to simultaneously improve transmittance and suppress foaming.

[0176] [Other Implementation Methods]

[0177] like Figure 4 As shown, the light source 3 is equipped with a filter 5 that cuts off light with a wavelength of 365 nm or less. Ultraviolet light L1 emitted from the LED element 4 can also irradiate the target film 1 in a state where the wavelength of light cut off by the filter 5 is 365 nm or less. The filter 5 is, for example, composed of a dielectric multilayer film.

Claims

1. A method for treating a radiation-sensitive composition, characterized in that, The radiation-sensitive composition has the following characteristics: A resin (A) soluble in alkaline aqueous solutions is a copolymer of a free radical polymerizable compound (a) having an acid group, a free radical polymerizable compound (b) having an epoxy group, and other free radical polymerizable compounds (c). Radiation-sensitive acid-producing compounds (B); The method includes the following steps (α): By irradiating the radiation-sensitive composition with ultraviolet light in the range of main peak wavelength above 375nm and below 395nm through an LED element, the transmittance of the radiation-sensitive composition is improved. The free radical polymerizable compound (a) having an acid group is one or both of the monomers constituting structural units having carboxyl groups and structural units constituting phenolic hydroxyl groups. The epoxy-containing free radical polymerizable compound (b) is glycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, methyl (meth)acrylate, 2-(3,4-epoxycyclohexyl)ethyl (meth)acrylate, or 3,4-epoxytricyclo[5.2.1.0]. 2,6 One or more of the following: decyl (meth)acrylate, (3-methyloxetane-3-yl)meth (meth)acrylate, (3-ethyloxetane-3-yl)(meth)acrylate, (oxetane-3-yl)meth (meth)acrylate, and (3-ethyloxetane-3-yl)meth (meth)acrylate. The radiation-sensitive acid-producing compound (B) is one or more selected from 1,2-quinone diazide compounds, ononium salt compounds, halogen-containing compounds, sulfone compounds, sulfonic acid compounds, sulfonylimide compounds, and diazomethane compounds. The process (α) is performed after the processes of pre-baking, exposure and development are sequentially performed on the radiation-sensitive composition.

2. The method for processing the radiation-sensitive composition according to claim 1, characterized in that, The half-width of the ultraviolet light is less than 20 nm.

3. The method for processing the radiation-sensitive composition according to claim 1, characterized in that, The light intensity at a wavelength of 365 nm of the ultraviolet light is less than 10% of the light intensity at the main peak wavelength.

4. The method for processing the radiation-sensitive composition according to claim 2, characterized in that, The light intensity at a wavelength of 365 nm of the ultraviolet light is less than 10% of the light intensity at the main peak wavelength.

5. The method for processing the radiation-sensitive composition according to claim 3, characterized in that, The process (α) is to irradiate the radiation-sensitive composition with ultraviolet light from the LED element through a filter of light with a cutoff wavelength of less than 365 nm.

6. The method for processing the radiation-sensitive composition according to claim 4, characterized in that, The process (α) is to irradiate the radiation-sensitive composition with ultraviolet light from the LED element through a filter of light with a cutoff wavelength of less than 365 nm.

7. The method for processing the radiation-sensitive composition according to any one of claims 1 to 6, characterized in that, The radiosensitive acid-producing compound (B) is a 1,2-quinone diazide compound.

8. The method for processing the radiation-sensitive composition according to any one of claims 1 to 6, characterized in that, The proportion of the radiation-sensitive acid-producing compound (B) in the radiation-sensitive composition is 15-30 parts by weight relative to 100 parts by weight of the resin (A).

9. A method for processing a radiation-sensitive composition according to any one of claims 1 to 6, characterized in that, The other free radical polymerizable compound (c) is a structural unit derived from at least one monomer selected from alicyclic (meth)acrylates, aromatic (meth)acrylates, aromatic vinyl compounds, N-substituted maleimide compounds, and heterocyclic vinyl compounds.

10. A method for processing a radiation-sensitive composition according to any one of claims 1 to 6, characterized in that, The method has the following characteristics: The process of forming a basement membrane (β1). In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and After step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development. The process (α) is performed after the process (β3).

11. The method for processing the radiation-sensitive composition according to claim 7, characterized in that, The proportion of the radiation-sensitive acid-producing compound (B) in the radiation-sensitive composition is 15-30 parts by weight relative to 100 parts by weight of the resin (A).

12. The method for processing the radiation-sensitive composition according to claim 11, characterized in that, The other free radical polymerizable compound (c) is a structural unit derived from at least one monomer selected from alicyclic (meth)acrylates, aromatic (meth)acrylates, aromatic vinyl compounds, N-substituted maleimide compounds, and heterocyclic vinyl compounds.

13. The method for processing the radiation-sensitive composition according to claim 12, characterized in that, The method has the following characteristics: The process of forming a basement membrane (β1). In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and After step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development. The process (α) is performed after the process (β3).

14. The method for processing the radiation-sensitive composition according to claim 7, characterized in that, The other free radical polymerizable compound (c) is a structural unit derived from at least one monomer selected from alicyclic (meth)acrylates, aromatic (meth)acrylates, aromatic vinyl compounds, N-substituted maleimide compounds, and heterocyclic vinyl compounds.

15. The method for processing the radiation-sensitive composition according to claim 14, characterized in that, The method has the following characteristics: The process of forming a basement membrane (β1). In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and After step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development. The process (α) is performed after the process (β3).

16. The method for processing the radiation-sensitive composition according to claim 8, characterized in that, The other free radical polymerizable compound (c) is a structural unit derived from at least one monomer selected from alicyclic (meth)acrylates, aromatic (meth)acrylates, aromatic vinyl compounds, N-substituted maleimide compounds, and heterocyclic vinyl compounds.

17. The method for processing the radiation-sensitive composition according to claim 7, characterized in that, The method has the following characteristics: The process of forming a basement membrane (β1). In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and After step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development. The process (α) is performed after the process (β3).

18. The method for processing the radiation-sensitive composition according to claim 17, characterized in that, The proportion of the radiation-sensitive acid-producing compound (B) in the radiation-sensitive composition is 15-30 parts by weight relative to 100 parts by weight of the resin (A).

19. The method for processing the radiation-sensitive composition according to claim 8, characterized in that, The method has the following characteristics: The process of forming a basement membrane (β1). In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and After step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development. The process (α) is performed after the process (β3).

20. The method for processing the radiation-sensitive composition according to claim 16, characterized in that, The method has the following characteristics: The process of forming a basement membrane (β1). In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and After step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development. The process (α) is performed after the process (β3).

21. The method for processing the radiation-sensitive composition according to claim 9, characterized in that, The method has the following characteristics: The process of forming a basement membrane (β1). In step (β2), the radiation-sensitive composition is coated onto the substrate membrane formed by step (β1), and After step (β2), the radiation-sensitive composition is subjected to a series of processes (β3) including pre-baking, exposure and development. The process (α) is performed after the process (β3).

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