Negative photosensitive resin composition, dry film, cured product, and electronic component

Abstract

Provided is a novel negative photosensitive resin composition having excellent resolution without using a resin component which can be subjected to PFAS regulation. Provided is a negative photosensitive resin composition containing a polyhydroxy amide compound containing a structural unit represented by formula (1), a crosslinking agent, and a photoacid generator.

Description

Negative photosensitive resin composition, dry film, cured product, and electronic component

[0001] The present invention relates to a negative photosensitive resin composition, a dry film, a cured product, and an electronic component.

[0002] Photosensitive resin compositions containing polyimide precursors exhibit excellent properties such as insulating properties, heat resistance, and mechanical strength, and are therefore widely used as insulating films in various fields such as semiconductors and electronic components.

[0003] In recent years, the trend toward higher performance and smaller size of electronic components and electrical equipment has led to a demand for higher integration of semiconductor elements. To meet this demand, technologies for higher performance and smaller size have been developed in the field of semiconductor element packaging, such as wafer-level packaging. The insulating film used in the redistribution layer requires excellent resolution to allow for finer pattern formation.

[0004] Patent Document 1 discloses a photosensitive resin composition containing a polybenzoxazole precursor, a compound that generates an acid upon irradiation with actinic rays in a specific wavelength range, a crosslinkable or polymerizable compound, and a compound that generates an acid upon heating. According to the disclosure of Patent Document 1, a negative-type photosensitive resin composition is provided that exhibits good sensitivity and resolution, and provides good chemical resistance, heat resistance, and mechanical properties.

[0005] Japanese Patent Application Laid-Open No. 2012-203359

[0006] However, in recent years, restrictions on the use of forever chemicals such as perfluoroalkyl compounds (PFAS) have been considered internationally due to reports of their association with health hazards. The negative-tone photosensitive resin composition of Patent Document 1 may contain perfluoroalkyl groups in the polybenzoxazole precursor in view of exposure light transparency and developability, and may be subject to PFAS regulations. In the future, there will be a demand for negative-tone photosensitive resin compositions that can comply with PFAS regulations and have properties equivalent to those of conventional negative-tone photosensitive resin compositions.

[0007] The present invention has been made in view of the above-mentioned problems, and aims to provide a new negative-type photosensitive resin composition that has excellent resolution without using a resin component that may be subject to PFAS regulations. It also aims to provide a dry film having a resin layer formed from the negative-type photosensitive resin composition, a cured product formed from the negative-type photosensitive resin composition or a resin layer of the dry film, and an electronic component having the cured product.

[0008] One aspect of the present invention is a negative-type photosensitive resin composition, which includes a polyhydroxyamide compound containing a structural unit represented by the following formula (1), a crosslinking agent, and a photoacid generator:

[0009] The negative photosensitive resin composition of the above embodiment preferably further contains a basic compound.

[0010] In the negative photosensitive resin composition of the above embodiment, the weight average molecular weight of the polyhydroxyamide compound is preferably 2,000 to 20,000.

[0011] Another aspect of the present invention is a dry film, which includes a resin layer formed from the negative-type photosensitive resin composition of the above aspect.

[0012] Another aspect of the present invention is a cured product formed from the negative photosensitive resin composition of the above aspect or the resin layer of the dry film of the above aspect.

[0013] Another aspect of the present invention is an electronic component, which has the cured product of the above aspect.

[0014] The present invention provides a new negative-type photosensitive resin composition having excellent resolution without using a resin component that may be subject to PFAS regulations. It also provides a dry film having a resin layer formed from the negative-type photosensitive resin composition, a cured product formed from the negative-type photosensitive resin composition or a resin layer of the dry film, and an electronic component having the cured product.

[0015] Hereinafter, embodiments of the present disclosure will be described in detail. In this specification, the expression "a to b" in the description of a range of values ​​means a to b, unless otherwise specified.

[0016] In this specification, when multiple upper limit values ​​and multiple lower limit values ​​are separately described, all numerical ranges that can be set by freely combining these upper limit values ​​and lower limit values ​​are considered to be described in this specification.

[0017] In this specification, when a compound is described, its isomers are also described.

[0018] In this specification, the solid content means the components constituting the photosensitive resin composition or the composition other than the solvent (particularly the organic solvent) for each raw material, and is based on mass unless otherwise specified.

[0019] 1. Negative Photosensitive Resin Composition The negative photosensitive resin composition of this embodiment contains a polyhydroxyamide compound containing the specific structural unit shown below, a crosslinking agent, and a photoacid generator. The negative photosensitive resin composition of this embodiment preferably further contains a basic compound. From the viewpoint of compliance with PFAS regulations for the negative photosensitive resin composition as a whole, the negative photosensitive resin composition of this embodiment preferably does not substantially contain a compound having a perfluoroalkyl group.

[0020] 1-1. Polyhydroxyamide Compound The polyhydroxyamide compound of this embodiment contains a structural unit represented by the following formula (1). The polyhydroxyamide compound of this embodiment is not particularly limited in structure as long as it can undergo a crosslinking reaction with a crosslinking agent in the presence of an acid. It is preferable that the polyhydroxyamide compound of this embodiment does not have a perfluoroalkyl group in its structure.

[0021] The polyhydroxyamide compound may have an alkali-soluble group at its terminal. The alkali-soluble group at the terminal is not particularly limited, and examples thereof include functional groups such as an alcoholic hydroxyl group, a phenolic hydroxyl group, an acid anhydride group, a carboxyl group, a sulfonic acid group, a sulfonamide group, and an active methylene group. From the viewpoint of solubility in a developer, it is preferable that the terminal group have a carboxyl group or a phenolic hydroxyl group.

[0022] Among these alkali-soluble groups, phenolic hydroxyl groups are particularly preferred. When a polyhydroxyamide compound has a terminal phenolic hydroxyl group, the solubility of the polyhydroxyamide compound in a developer can be improved. Furthermore, since the phenolic hydroxyl group has lower reactivity than a carboxyl group, excessive reaction with a crosslinking agent is suppressed, and the solubility of unexposed areas in a developer can be maintained even after a PEB process. This allows the resolution to be maintained, and it is presumed that a negative-type photosensitive resin composition capable of forming a finer L / S pattern with a high aspect ratio can be provided.

[0023] The alkali-soluble groups contained at the terminals of these polyhydroxyamide compounds may be those present as residues of monomers constituting the polyhydroxyamide compounds, or may be those present as terminal structures introduced by a terminal-capping agent having an alkali-soluble group. The alkali-soluble groups contained at the terminals of the polyhydroxyamide compounds are preferably those present as terminal structures introduced by a terminal-capping agent having an alkali-soluble group.

[0024] The end-capping agent is not particularly limited, and examples thereof include compounds having one amino group and a hydroxyl group, such as aminophenol compounds, hydroxybenzylamine compounds, aminobenzyl alcohol compounds, and alcoholamine compounds; compounds having one carboxyl group and a hydroxyl group, such as hydroxy acids; acid anhydride compounds having a hydroxyl group, such as hydroxy acid anhydrides; compounds having an amino group and a carboxyl group, such as aminobenzoic acid and amino acids; and acid anhydride compounds, such as phthalic anhydride and 5-norbornene-2,3-dicarboxylic anhydride.

[0025] The polyhydroxyamide compound may contain a repeating structure other than that of the above formula (1), for example, a copolymer such as that of the following formula (2).

[0026] (In the formula, R represents a divalent organic group, and m and n represent the mole fractions of the repeating units represented by the brackets [ ].)

[0027] In the above formula (2), R represents a divalent organic group. From the viewpoint of complying with PFAS regulations, R is preferably a divalent non-fluorinated organic group. The divalent non-fluorinated organic group is a divalent organic group that does not have a fluorine atom. For example, a single bond, —O—, —S—, —S ２ -, -SO ２ -, -CO-, -SO-, -CH ２ -, -(CH ２ ) ３ In order to further improve the i-line transmittance and alkali solubility of the polyhydroxyamide compound, R is preferably -SO ２ It is more preferable that it is -.

[0028] In the above formula (2), m and n represent the molar fraction of the repeating unit represented by each bracket [ ]. The sum of m and n is 100 mol %. From the viewpoint of obtaining a negative-type photosensitive resin composition having excellent resolution, m is preferably 20 mol % or more, 40 mol % or more, 55 mol % or more, etc. Furthermore, m can be 100 mol % or less, 75 mol % or less, 70 mol % or less, etc., and from the viewpoint of obtaining a negative-type photosensitive resin composition having excellent resolution and sensitivity, m = 100 mol % is preferred. In other words, it is preferred that the repeating structure of the polyhydroxyamide compound consists essentially of the repeating structure represented by the above formula (1). n is preferably 0 mol % or more, 25 mol % or more, 30 mol % or more, etc., and 75 mol % or less, 50 mol % or less, 40 mol % or less, etc. are preferred.

[0029] The weight-average molecular weight (Mw) of the polyhydroxyamide compound is preferably 2,000 to 20,000, more preferably 2,000 to 15,000, even more preferably 3,000 to 15,000, and particularly preferably 4,000 to 10,000. By setting the weight-average molecular weight within such a range, it becomes possible to form a finer L / S pattern with a higher aspect ratio.

[0030] The number average molecular weight (Mn) of the polyhydroxyamide compound is preferably 1,000 to 10,000, more preferably 1,500 to 6,000.

[0031] The polydispersity index (PDI) of the polyhydroxyamide compound is preferably 1.5 to 5.0, more preferably 1.5 to 4.5.

[0032] When the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity index (PDI) of the polyhydroxyamide compound are within the above ranges, a favorable balance is achieved between the solubility in a developer in the unexposed area and the reaction with a crosslinker during exposure, making it possible to obtain a negative-type photosensitive resin composition with superior resolution.

[0033] In this specification, the weight average molecular weight and number average molecular weight are values ​​measured by gel permeation chromatography (GPC) (GL7700 manufactured by GL Science) and converted into standard polystyrene. Specific measurement conditions are as follows:

[0034] Column: TSKgel αM (manufactured by Tosoh Corporation) Column temperature: 40°C Eluent composition: 100 mmol / L H ３ P.O. ４ (H ３ P.O. ４ NMP solution containing 85% aqueous solution as raw material) and 10 mmol / L LiBr Eluent flow rate: 0.5 mL / min Calibration standard reagent: polystyrene Detector wavelength: 260 nm and 300 nm Detector temperature: room temperature (approximately 25°C) Baseline range during analysis: 15 to 40 minutes Molecular weight calculation range during analysis: 20 to 35 minutes

[0035] In this specification, the polydispersity index (PDI) is calculated by the following formula: PDI=Mw / Mn

[0036] The concentration of chlorine atoms (or chlorine ions) contained in the molecular structure of the polyhydroxyamide compound is not particularly limited, and is preferably 5 ppm by mass or less relative to the total mass of the polyhydroxyamide compound. The lower the concentration of chlorine atoms (or chlorine ions) contained in the molecular structure of the negative-type photosensitive resin composition, the easier it is to improve the insulation reliability of the cured product.

[0037] The alkaline dissolution rate of the polyhydroxyamide compound is not particularly limited, and from the viewpoint of obtaining a negative-type photosensitive resin composition having excellent developability and sensitivity, it can be, for example, 10 to 1000 nm / sec, more preferably 50 to 700 nm / sec, and even more preferably 100 to 500 nm / sec. If the alkaline dissolution rate is too low, the unexposed areas may not dissolve sufficiently, making pattern formation difficult, while if the alkaline dissolution rate is too high, sensitivity may decrease or the pattern may swell during development. The alkaline dissolution rate of the polyhydroxyamide compound can be measured by the method described in the Examples below.

[0038] 1-2. Crosslinking Agent The crosslinking agent is not particularly limited and can be any known crosslinking agent, such as a melamine compound, a guanamine compound, a triazine compound, an epoxy compound, an oxetane compound, an isocyanate compound, or an oxazoline compound. The crosslinking agent is preferably a compound having at least one selected from the group consisting of a methoxymethyl group and a methylol group. These functional groups undergo a crosslinking reaction with phenolic hydroxyl groups or carboxyl groups contained in polyhydroxyamide compounds or the like upon heating, using the acid generated from a photoacid generator (described below) as the active species. Negative photolithography (pattern formation) is therefore achieved by exposure, PEB, and development. Furthermore, further heating after pattern formation promotes the curing reaction of the negative photosensitive resin composition, resulting in the development of excellent properties as a cured product.

[0039] Furthermore, the crosslinking agent preferably contains a heterocycle in order to improve the resolution of the negative photosensitive resin composition and the insulating reliability after curing. The heterocycle is not particularly limited and contains one or more heteroatoms such as boron, nitrogen, oxygen, phosphorus, sulfur, antimony, arsenic, bismuth, selenium, silicon, tellurium, or tin, and includes a 3-, 4-, 5-, 6-, 7-, or 8-membered saturated or unsaturated ring. From the viewpoints of the resolution of the negative photosensitive resin composition and the insulating reliability of the cured product, the heterocycle is preferably a nitrogen-containing heterocycle, and more preferably a heterocycle containing multiple nitrogen atoms.

[0040] Specifically, from the viewpoint of being able to provide a composition, compounds having a triazine structure such as hexamethylolmelamine and hexamethoxymethylmelamine, compounds having a guanamine structure such as tetramethylolbenzoguanamine and tetramethoxymethylbenzoguanamine, triazine structures containing a triazine ring, compounds having a glycoluril structure such as tetramethylolglycoluril and tetramethoxyglycoluril, and compounds having an imidazolidinone structure such as 1,3-bis(methoxymethyl)-2-imidazolidinone are more preferred. Of these, compounds having a negative photosensitive resin structure and compounds having a guanamine structure, which are capable of forming L / S patterns with finer and higher aspect ratios, are particularly preferred.

[0041] 1-3. Photoacid Generator The photoacid generator is not particularly limited as long as it generates an acid upon irradiation with light such as ultraviolet light or visible light. Examples include naphthoquinone diazide compounds, diaryl sulfonium salts, triaryl sulfonium salts, dialkylphenacylsulfonium salts, diaryliodonium salts, aryl diazonium salts, aromatic tetracarboxylic acid esters, aromatic sulfonate esters, nitrobenzyl esters, aromatic N-oxyamidosulfonates, aromatic N-oxyimidosulfonates, aromatic sulfamides, oxime sulfonate compounds, naphthalimides, and benzoquinone diazosulfonate esters. These compounds can be used alone or in combination in any ratio. From the viewpoint of achieving better resolution and insulation reliability, the photoacid generator is preferably an oxime sulfonate compound, and more preferably one having a structure represented by the following formula (3): (wherein X is a hydrocarbon group or a halogen atom, m is an integer of 0 to 3, R ３ is a hydrogen atom, a hydrocarbon group, an organic group including a ketone group, or a halogen atom.

[0042] X in the above formula (3) is not particularly limited and can be, for example, a hydrocarbon group (e.g., an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc.) or a halogen atom. The hydrocarbon group may have a substituent and can have a linear, branched, or cyclic structure. A linear or branched hydrocarbon group having 1 to 4 carbon atoms is preferably used. A chlorine atom or a fluorine atom is preferably used as the halogen atom.

[0043] In the above formula (3), m represents an integer of 0 to 3, and is preferably 0 or 1. When m is 2 or 3, multiple Xs may be the same or different.

[0044] R in the above formula (3) ３ is preferably a hydrogen atom, a hydrocarbon group, an organic group including a ketone group, or a halogen atom. The hydrocarbon group (e.g., an alkyl group, an alkenyl group, an alkynyl group, an aryl group, etc.) may be unsubstituted or may be substituted with a halogen atom.

[0045] The hydrocarbon group is preferably a linear, branched or cyclic group having 1 to 20 carbon atoms, more preferably a linear, branched or cyclic group having 1 to 10 carbon atoms. The halogen atom may be a chlorine atom or a fluorine atom.

[0046] Commercially available oxime sulfonate compounds include Irgacure PAG103, Irgacure PAG108, Irgacure PAG121, and Irgacure PAG203 manufactured by BASF.

[0047] 1-4. Basic Compound The negative photosensitive resin composition of this embodiment preferably contains a basic compound. In particular, when the negative photosensitive resin composition of this embodiment contains a basic compound, the acid generated from the photoacid generator upon exposure can be prevented from diffusing into unexposed areas, thereby improving resolution and preventing development residues from being generated in unexposed areas after development.

[0048] The basic compound is not particularly limited, and examples thereof include trimethylamine, diethylamine, triethylamine, N,N-diisopropylethylamine, di-n-propylamine, tri-n-propylamine, tri-n-pentylamine, tribenzylamine, diethanolamine, triethanolamine, tris(2-methoxy)amine, bis(2-methoxy)amine, tris(2-ethoxy)amine, bis(2-ethoxy)amine, N-methyldiethanolamine, N-ethyldiethanolamine, N,N-dimethylethanolamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, ethylenediamine, N,N,N',N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4, Amine compounds such as 4'-diaminodiphenylamine; amide compounds such as formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, and benzamide; lactams such as pyrrolidone and N-methylpyrrolidone; methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, and 1,3-diphenyl Examples of suitable amine compounds include urea and other urea compounds; nitrogen-containing heterocyclic compounds such as imidazole, benzimidazole, 4-methylimidazole, 8-oxyquinoline, acridine, purine, pyrrolidine, piperidine, 2,4,6-tri(2-pyridyl)-S-triazine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, and pyridine; and morpholine compounds such as morpholine and 4-methylmorpholine. These compounds can be used alone or in combination in any ratio. Among these, amine compounds are preferred, and alcoholamines such as N-methyldiethanolamine, N-ethyldiethanolamine, and N,N-dimethylethanolamine are more preferred, with diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, and N,N-dimethylethanolamine being even more preferred.

[0049] The negative photosensitive resin composition of this embodiment may contain a solvent. The solvent is not particularly limited, and examples thereof include ethers, esters, glycol esters, ketones, lactones, lactams, sulfoxides, tetramethylurea, dimethyl sulfone, and pyridine.

[0050] Examples of ethers include 2-methoxy-1-methylethyl acetate (PGMEA), ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether.

[0051] Examples of esters include ethyl acetate, butyl acetate, ethyl lactate, methyl 3-methoxypropionate, methyl 2-methoxypropionate, ethyl 3-methoxypropionate, ethyl 2-methoxypropionate, ethyl 3-ethoxypropionate, and ethyl 2-ethoxypropionate.

[0052] Examples of ketones include methyl ethyl ketone; methyl isobutyl ketone (4-methyl-2-pentanone); 2-heptanone; monoketone cycloalkanones such as cyclopropanone, cyclobutanone, cyclopentanone, cyclohexanone, methylcyclohexanone, cycloheptanone, cyclooctanone, 2-norbornanone, 2-methylcyclohexanone, 4-methylcyclohexanone, 3-methylcyclohexanone, and 2,2-dimethylcyclopentanone; diketone cycloalkanones such as 1,3-cyclopentanedione, 3-methyl-1,2-cyclopentanedione, 1,2-cyclohexanedione, 1,3-cyclohexanedione, 1,4-cyclohexanedione, and 2-methyl-1,3-cyclopentanedione; Examples include cycloalkenones such as 4-methyl-2-cyclopentenone, 2-cyclohexenone, 2-cyclopenten-1-one, and 2-cyclohexen-1-one; and cyclic ketones having a heterocyclic skeleton such as 2-azetidinone, 4,5-dihydro-3(2H)-thiophenone, 4-oxothiane, and dihydrolevogluconocene.

[0053] Examples of glycol esters include carbitol acetate, ethyl cellosolve acetate, and ethylene glycol monoethyl ether acetate.

[0054] Examples of lactones include γ-butyrolactone, examples of lactams include N-methylpyrrolidone and N-methylcaprolactam, and examples of sulfoxides include dimethyl sulfoxide and hexamethyl sulfoxide.

[0055] These solvents can be used alone or in combination of two or more in any ratio. Among these solvents, lactones or cyclic ketones are preferred, and γ-butyrolactone or cyclopentanone is preferred, from the viewpoint of excellent affinity with each component in the negative photosensitive resin composition. Furthermore, from the viewpoint of excellent solvent removability during drying of the negative photosensitive resin composition and suitability for the edge rinse step in semiconductor manufacturing, cyclic ketones are preferred, and monoketone cycloalkanones are more preferred, with cyclopropanone, cyclobutanone, cyclopentanone, cyclohexanone, methylcyclohexanone, cycloheptanone, cyclooctanone, 2-norbornanone, 2-methylcyclohexanone, 4-methylcyclohexanone, 3-methylcyclohexanone, and 2,2-dimethylcyclopentanone being even more preferred, and cyclopentanone being particularly preferred.

[0056] 1-6. Other Components The negative-type photosensitive resin composition of the present embodiment may contain other components as long as the effects of the disclosed technology are not impaired. Examples of other components include known components that can be contained in negative-type photosensitive resin compositions, such as fillers, adhesives, surfactants, plasticizers, thermal acid generators, sensitizers, leveling agents, colorants, fibers, and fine particles.

[0057] The surfactant is not particularly limited, and examples thereof include fluorine-based surfactants, silicone-based surfactants, etc. Commercially available fluorine-based surfactants include the "Megafac" series manufactured by DIC Corporation (e.g., Megafac F-281, F-477, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F-561, F-563, F-569, etc.). Commercially available silicone surfactants include the BYK-Chemie surface conditioner series (e.g., BYK-302, BYK-307, BYK-310, BYK-322, BYK-323, BYK-326, BYK-331, BYK-332, BYK-333, BYK-348, BYK-349, BYK-377, BYK-378, BYK-3455, BYK-3760, etc.). These may be used alone or in combination of two or more.

[0058] 2. Preparation of Negative Photosensitive Resin Composition The negative photosensitive resin composition of this embodiment can be obtained by mixing the polyhydroxyamide compound, crosslinking agent, photoacid generator, and any other optional components, including a basic compound. The components can be mixed under heating, if necessary.

[0059] 2-1. Polyhydroxyamide Compound The content of the polyhydroxyamide compound can be 50 to 80% by mass, where the total mass of the solid content of the negative-type photosensitive resin composition is 100% by mass. Here, the solid content mass in this specification refers to the mass of the residue after complete evaporation of the volatile components.

[0060] 2-2. Crosslinking Agent The content of the crosslinking agent can be 10 to 40% by mass, where the total mass of the solids in the negative-tone photosensitive resin composition is 100% by mass. Furthermore, when the crosslinking agent has methoxymethyl groups and / or methylol groups, the content of the crosslinking agent can be such that the ratio of the number of methoxymethyl groups and / or methylol groups contained in the crosslinking agent to the number of phenolic hydroxyl groups contained in the negative-tone photosensitive resin composition (methoxymethyl groups and / or methylol groups:phenolic hydroxyl groups) is 120:100 to 200:100. By achieving such a ratio, the resolution of the negative-tone photosensitive resin composition and the insulation reliability after curing can be improved.

[0061] 2-3. Photoacid Generator The content of the photoacid generator can be 0.5 to 10% by mass, and preferably 1 to 5% by mass, when the total mass of the solid content of the negative-type photosensitive resin composition is taken as 100% by mass.

[0062] 2-4. Basic Compound When a basic compound is added, its content can be 0.01 to 0.50% by mass, and preferably 0.08 to 0.40% by mass, relative to the total mass of the solids in the negative photosensitive resin composition taken as 100% by mass. By setting the content within this range, it becomes easier to prevent development residues from being generated in unexposed areas after the negative photosensitive resin composition is developed.

[0063] 3. Dry Film The dry film of the present embodiment includes a substrate and a resin layer formed on the substrate using the negative photosensitive resin composition of the present embodiment. In addition, a protective film may be further laminated on the surface of the resin layer to protect the resin layer.

[0064] The resin layer can be obtained, for example, by applying a negative photosensitive resin composition onto a substrate, adjusting the thickness of the resin layer using a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, spray coater, etc., and drying the resin layer. The thickness of the resin layer is not particularly limited and can be set to 1 to 150 μm depending on the application.

[0065] The substrate is not particularly limited, and examples thereof include metal foils such as copper foils; and films such as polyimide films, polyester films, and polyethylene naphthalate (PEN) films.

[0066] The protective film is not particularly limited, and polyethylene film, polytetrafluoroethylene film, polypropylene film, paper, etc. can be used. It is preferable to select a protective film such that the adhesion between the protective film and the resin layer is lower than the adhesion between the substrate and the resin layer. In order to make the adhesion between the protective film and the resin layer lower than the adhesion between the substrate and the resin layer, a protective film whose surface has been subjected to a release treatment can be used.

[0067] 4. Cured Product The cured product of this embodiment is obtained by curing the resin layer of the above-described negative photosensitive resin composition or dry film. The cured product may be a patterned cured product. Examples of methods for producing a patterned cured product include the following methods.

[0068] 4-1. Dry Coating Film Forming Step The dry coating film forming step is a step of applying the above-described negative photosensitive resin composition onto a substrate to form a coating film, and then drying the coating film. In the dry coating film forming step, it is also possible to form a dry coating film on the substrate by transferring a resin layer of a dry film onto the substrate.

[0069] The method for applying the negative photosensitive resin composition onto a substrate is not particularly limited, and examples thereof include a method of applying the composition using a spin coater, bar coater, blade coater, curtain coater, screen printing machine, etc., a method of spraying the composition using a spray coater, and an inkjet method. The thickness of the applied film is not particularly limited, and can be, for example, 10 μm or less, 5 μm or less, or 3 μm or less. By reducing the film thickness, finer L / S patterning becomes possible while maintaining the aspect ratio of the pattern.

[0070] The method for drying the coating film is not particularly limited, and examples thereof include air drying, heat drying in an oven or on a hot plate, vacuum drying, etc. Conditions for heat drying include, for example, a heating temperature of 70 to 140°C and a drying time of 1 to 30 minutes.

[0071] The transfer of the resin layer of the dry film onto the substrate is preferably carried out under pressure and heat using a vacuum laminator, etc. The heating temperature can be, for example, 60 to 100°C.

[0072] The substrate is not particularly limited, and may be, for example, a printed wiring board on which a circuit is formed, a flexible printed wiring board, or a wafer on which a semiconductor element is formed.

[0073] 4-2. Exposure Step In the exposure step, the dried coating film formed in the dried coating film formation step is irradiated with radiation through a photomask capable of forming a desired pattern, thereby sensitizing the photoacid generator in the exposed area and generating active species. If patterning is not required, there is no need to use a photomask. Alternatively, a pattern may be directly written with a laser using a direct writing device.

[0074] The wavelength of the radiation used is one that can activate the photoacid generator, and in order to perform fine patterning, a maximum wavelength of 410 nm or less is preferred. The irradiation energy can be adjusted depending on the thickness of the formed dry coating film, and is, for example, 10 to 1500 mJ / cm. ２ As the exposure light source, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, a KRF laser, or the like can be used.

[0075] 4-3. PEB Process The PEB process is a process in which the dried coating film exposed in the exposure process is heat-treated to impart development resistance to the exposed areas of the dried coating film (hereinafter sometimes abbreviated as "exposed areas"). In the PEB process, the acid generated by the photoacid generator in the exposed areas acts as an active species to promote a crosslinking reaction between the polyhydroxyamide compound or the compound containing a phenolic hydroxyl group and the crosslinking agent, thereby making the exposed areas insoluble in the developer. The heating temperature in the PEB process can be 90 to 150°C, and the heating time can be 0.5 to 10 minutes. Heating can be performed using a known method such as a hot plate or a heating furnace.

[0076] The developing step is a step in which the dried coating film heated in the PEB step is treated with a developer to dissolve and remove the unexposed areas of the dried coating film in the developer, thereby obtaining a patterned coating film. As the developing method, a known method can be used, such as a rotary spray method, a paddle method, or an immersion method accompanied by ultrasonic treatment.

[0077] Known developers can be used, including, for example, aqueous solutions of inorganic alkalis such as sodium hydroxide, sodium carbonate, sodium silicate, and aqueous ammonia; organic amines such as ethylamine, diethylamine, triethylamine, and triethanolamine; and quaternary ammonium salts such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide. If necessary, water-soluble organic solvents such as methanol, ethanol, and isopropyl alcohol, as well as surfactants, can be added. The negative photosensitive resin composition of this embodiment can also exhibit excellent developability in organic solvent development using an organic solvent as the developer. Examples of developers for organic solvent development include ketone solvents such as cyclopentanone and cyclohexanone, ester solvents such as propylene glycol monomethyl acetate and butyl acetate, and ether solvents such as propylene glycol monomethyl ether. These can be used alone or in combination in any ratio.

[0078] After treatment with the developer, the coating film can be washed with a rinse solution as needed to obtain a patterned coating film. The rinse solution is not particularly limited, and examples thereof include pure water, methanol, ethanol, and isopropyl alcohol. These can be used alone or in combination in any ratio.

[0079] 4-5. Post-development heating step The post-development heating step is a step in which the patterned coating film formed in the development step is heated to complete curing of the patterned coating film and obtain a cured patterned coating film (cured product). The heating temperature can be 150 to 200°C, and the heating time can be 1 to 120 minutes. Heating can be performed by a known method such as a hot plate or an inert oven, and heating is preferably performed under a nitrogen atmosphere.

[0080] 5. Uses of Negative Photosensitive Resin Composition The negative photosensitive resin composition of this embodiment can be suitably used as a material for forming displays, semiconductor elements, electronic components, optical components, building materials, etc. Examples of materials for forming semiconductor elements include resist materials, buffer coating films, and insulating films for rewiring layers in wafer-level packages (WLP). Examples of materials for forming electronic components include printed wiring boards, interlayer insulating films, and wiring coating films.

[0081] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to the following. The components used in the examples and comparative examples are as follows.

[0082] Polyhydroxyamide compounds A-1 to A-10 were synthesized as follows. The components and molar ratios of each polyhydroxyamide compound, as well as the weight-average molecular weight, number-average molecular weight, and molecular weight dispersity of the resulting polyhydroxyamide compounds A-1 to A-10, are shown in Table 1.

[0083] Synthesis Example 1: Polyhydroxyamide Compound (A-1) (Mn: 2,200, Mw: 8,800) In a 120 mL vial equipped with a stirrer and a thermometer (room temperature), 6.32 g (24.5 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)propane (BAP) and 0.83 g (7.58 mmol) of 3-aminophenol were dissolved in 35 g of N-methylpyrrolidone (NMP) with stirring for 15 minutes. The vial was then immersed in an ice bath, and while maintaining the temperature in the vial at 0 to 5°C, 7.54 g (25.5 mmol) of 4,4'-oxybis(benzoyl chloride) (DEDC) was added as a solid over 10 minutes, followed by stirring in the ice bath for 30 minutes. After stirring for 18 hours at room temperature, the solution was poured into a large amount of ion-exchanged water, and the precipitate was collected. The resulting solid was dissolved in 32 g of cyclopentanone. 8 g of anion exchange resin (Organo Corporation, Amberlyst B-20) was added thereto and vigorously stirred for 1 hour. The stirred solution was concentrated and then added to a large amount of ion-exchanged water, and the precipitate was recovered. The precipitated solid was recovered and dried under reduced pressure to obtain polyhydroxyamide compound (A-1).

[0084] (A-1) Polyhydroxyamide compound

[0085] Synthesis Example 2: Polyhydroxyamide compound (A-2) (Mn: 6,200, Mw: 13,000) Polyhydroxyamide compound (A-2) was obtained in the same manner as in Synthesis Example 1, except that 6.36 g (24.6 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)propane (BAP), 0.56 g (5.09 mmol) of 3-aminophenol, 35 g of N-methylpyrrolidone (NMP), and 7.49 g (25.3 mmol) of 4,4′-oxybis(benzoyl chloride) (DEDC) were used.

[0086] Synthesis Example 3: Polyhydroxyamide Compound (A-3) (Mn: 3,400, Mw: 9,400) In a 120 mL vial equipped with a stirrer and a thermometer (room temperature), 8.27 g (28.0 mmol) of 4,4'-oxybis(benzoyl chloride) (DEDC) was dissolved in 24 g of N-methylpyrrolidone (NMP) with stirring for 15 minutes. The vial was then immersed in an ice bath, and while maintaining the temperature inside the vial at 0 to 5°C, a solution of 5.67 g (22.0 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)propane (BAP) and 8 g of NMP was added dropwise over 10 minutes, followed by stirring in the ice bath for 30 minutes. After stirring at room temperature for 3 hours, 2.00 g (18.3 mmol) of 3-aminophenol was added as a solid to the vial. After stirring at room temperature for 18 hours, the solution was poured into a large amount of ion-exchanged water, and the precipitate was collected. The obtained solid was dissolved in 32 g of tetrahydrofuran (THF). 8 g of anion-exchange resin (Organo Corporation, Amberlyst B-20) was added thereto, and the mixture was vigorously stirred for 1 hour. The stirred solution was poured into a large amount of ion-exchanged water, and the precipitate was collected. The precipitated solid was collected and then dried under reduced pressure to obtain polyhydroxyamide compound (A-3).

[0087] (Synthesis Example 4: Copolymerized polyhydroxyamide compound (A-4)) (Mn: 3,900, Mw: 13,000) (m=25, n=75) In a 120 mL vial equipped with a stirrer and a thermometer (room temperature), 1.58 g (6.11 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)propane (BAP) and 2,2-bis(3-amino-4-hydroxyphenyl)sulfone (SO ２ Polyhydroxyamide compound (A-4) was obtained in the same manner as in Synthesis Example 1, except that 5.14 g (18.3 mmol) of 4,4'-oxybis(benzoyl chloride) (DEDC) and 0.85 g (7.80 mmol) of 3-aminophenol were dissolved in 35 g of N-methylpyrrolidone (NMP) with stirring, and then the vial was immersed in an ice bath and 7.80 g (25.6 mmol) of 4,4'-oxybis(benzoyl chloride) (DEDC) was added while maintaining the temperature inside the vial at 0 to 5°C.

[0088] (A-4) Copolymerized polyhydroxyamide compound

[0089] (Synthesis Examples 5 to 8: Copolymerized polyhydroxyamide compounds (A-5) to (A-8)) 2,2-bis(3-amino-4-hydroxyphenyl)propane (BAP), 2,2-bis(3-amino-4-hydroxyphenyl)sulfone (SO ２ Polyhydroxyamide compounds (A-5) to (A-8) were obtained in the same manner as in Synthesis Example 3, except that the molar ratios of 4,4′-oxybis(benzoyl chloride) (DEDC) and 3-aminophenol (AP) were changed to those shown in Table 1.

[0090] (Synthesis Example 9: Polyhydroxyamide Compound (A-9)) (Mn: 2,500, Mw: 9,800) 2,2-bis(3-amino-4-hydroxyphenyl)propane (BAP) was replaced with 2,2-bis(3-amino-4-hydroxyphenyl)sulfone (SO ２ A polyhydroxyamide compound (A-9) was obtained in the same manner as in Synthesis Example 1, except that 6.85 g (24.4 mmol) of 3-aminophenol (AP), 0.86 g (7.87 mmol) of 3-aminophenol, 35 g of N-methylpyrrolidone (NMP), and 7.54 g (25.5 mmol) of 4,4′-oxybis(benzoyl chloride) (DEDC) were used.

[0091] (A-9) Polyhydroxyamide compound

[0092] Synthesis Example 10: Polyhydroxyamide compound (A-10) (Mn: 3,200, Mw: 9,500) Polyhydroxyamide compound (A-10) was obtained in the same manner as in Synthesis Example 1, except that 16.3 g (44.5 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAP) was used instead of 2,2-bis(3-amino-4-hydroxyphenyl)propane (BAP), and 1.80 g (22.0 mmol) of 3-aminophenol, 70 g of N-methylpyrrolidone (NMP), and 16.4 g (55.5 mmol) of 4,4′-oxybis(benzoyl chloride) (DEDC) were used.

[0093] (A-10) Polyhydroxyamide compound

[0094] Each polyhydroxyamide compound was evaluated as follows. The evaluation results are shown in Table 1.

[0095] (Evaluation of i-Line Transmittance) A cyclopentanone solution with a solids concentration of 20% by mass was prepared using the polyhydroxyamide compound obtained in the above Synthesis Example. This solution was spin-coated onto quartz glass to a film thickness of 3 μm after drying, and then heated and dried on a hot plate at 90° C. for 3 minutes to form a dried coating film of the polyhydroxyamide compound. The transmission spectrum of the dried coating film was measured using an ultraviolet-visible spectrophotometer (Jasco V-570, manufactured by JASCO Corporation). The transmission spectrum was measured under conditions of a bandwidth of 5 nm, a scanning speed of 400 nm / min, and a data reading interval of 1 nm. The transmittance of the i-line (wavelength 365 nm), which is the exposure wavelength, was evaluated according to the following evaluation criteria. (Evaluation Criteria) A: i-line transmittance of 70% or more but less than 80% B: i-line transmittance of 30% or more but less than 70% C: i-line transmittance of less than 30%

[0096] (Evaluation of Alkali Solubility) A 20% by mass cyclopentanone solution was prepared using the polyhydroxyamide compound obtained in the above Synthesis Example, spin-coated onto a silicon substrate, and dried by heating at 90°C for 3 minutes on a hot plate to form a dried coating film of the polyhydroxyamide compound. The initial film thickness of the dried coating film was measured using an optical interference film thickness meter, and then developed using a 2.38% aqueous tetramethylammonium hydroxide (TMAH) solution at 25°C. The dissolution time of the dried coating film was measured using a development rate measurement device (RDA-790, manufactured by Litho Tech Japan Co., Ltd.), and the alkali dissolution rate was calculated using the following formula: Alkali dissolution rate (nm / s) = initial film thickness (nm) / dissolution time (s) (Evaluation criteria) A: Dissolution rate is 100 nm / s or more and 500 nm / s or less B: Dissolution rate is more than 500 nm / s and 1000 nm / s or less C: Dissolution rate is more than 1000 nm / s

[0097] (Evaluation of Solvent Solubility) The solubility of the polyhydroxyamide compounds obtained in the above synthesis examples in cyclopentanone and propylene glycol monomethyl ether (PGME) was confirmed. When a negative photosensitive resin composition was prepared using a polyhydroxyamide compound that had low solubility in cyclopentanone, it was prepared using a mixed solvent of cyclopentanone and dimethyl sulfoxide. (Evaluation Criteria) A: Soluble in both cyclopentanone and PGME B: Insoluble in cyclopentanone and soluble in PGME, or soluble in cyclopentanone and insoluble in PGME C: Insoluble in both cyclopentanone and PGME

[0098] The molar ratios added in Table 1 represent mole % when the amount of DEDC added is taken as 100 mole %.

[0099] <Crosslinking Agent> (B-1) MW-390 (a hexamethoxymethyl melamine compound manufactured by Nippon Carbide Industries Co., Ltd.)

[0100] <Photoacid Generator> (C-1) PAG-103 (oxime sulfonate compound manufactured by BASF)

[0101] <Basic Compound> (D-1) Triethanolamine (TEA)

[0102] <Solvent> Cyclopentanone (Tokyo Chemical Industry Co., Ltd.) Tetrahydrofuran (THF) (Fujifilm Wako Pure Chemical Industries, Ltd.) Dimethyl sulfoxide (DMSO) (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0103] <Preparation of negative photosensitive resin composition> Each component was blended in the amount shown in Table 2 below, and dissolved and adjusted with a solvent so that the concentration of non-volatile components in the varnish was 30%, thereby obtaining a varnish of the negative photosensitive resin composition of each Example and Comparative Example. Note that, of the blending amounts of each component in Table 2, the blending amount of each component, excluding the blending amount of the solvent, indicates the solid content parts by mass.

[0104] <Evaluation> The negative photosensitive resin compositions obtained in the examples and comparative examples were evaluated as follows. The results of the evaluations are shown in Table 2.

[0105] (Evaluation of Resolution and Sensitivity by Alkaline Development) The varnish of each Example and Comparative Example was applied to a silicon wafer using a spin coater to a film thickness of 3.0 μm after curing, and then dried on a hot plate at 90°C for 3 minutes to obtain a dried coating film of the negative photosensitive resin composition of each Example and Comparative Example. This dried coating film was exposed to a test pattern with L / S of 2 / 2 μm to 10 / 10 μm at 1 μm intervals using a contact exposure machine (UVE-251S+EL-100 (manufactured by Minei Electric Mfg. Co., Ltd.)), and then post-exposure bake (PEB) was performed for 60 seconds on a hot plate. The heating temperatures for the PEB process were 120°C and 140°C, respectively. The coating was then developed for 30 seconds using a 2.38% TMAH aqueous solution, rinsed for 30 seconds with ultrapure water, and spin-dried for 30 seconds to obtain a patterned sample.

[0106] Each sample was cut so that a cross section perpendicular to the longitudinal direction of the pattern could be observed. The cut surface of the pattern was observed using a scanning electron microscope (10,000x magnification), and the minimum L / S size of properly patterned and the exposure dose at that time are listed in Table 2. A smaller minimum L / S size indicates better resolution, and a lower exposure dose indicates better sensitivity. A sample in which each pattern was patterned vertically without collapsing was judged to be properly patterned. The pattern shape was evaluated according to the following evaluation criteria. (Evaluation criteria) A: A roughly rectangular pattern was formed, and there was no development residue in the unexposed areas. B: A roughly rectangular pattern was formed, but there was development residue in the unexposed areas. C: A roughly rectangular pattern was not formed, or a pattern larger than the desired L / S width was formed due to swelling of the pattern, etc.

[0107] (Evaluation of Resolution by Organic Solvent Development) The resolution by organic solvent development was evaluated in the same manner as in the evaluation of resolution by alkaline development, except that the varnish of Example 1 was used, and development for 10 seconds was carried out twice using cyclopentanone instead of the 2.38% TMAH aqueous solution as the developer, and the heating temperature in the PEB step was set to 140° C. The negative photosensitive resin composition of Example 1 was successfully patterned with an L / S of 2 / 2 μm, and it was confirmed that the composition also exhibited excellent resolution by organic solvent development.

[0108] (Evaluation of PFAS Regulation) The polyhydroxyamide compounds A1 to A10 used in each of the Examples and Comparative Examples were evaluated to see if they could be subject to PFAS regulation. (Evaluation Criteria) PASS: Not subject to PFAS regulation FAIL: May be subject to PFAS regulation

[0109] CROSS-REFERENCE TO RELATED APPLICATIONS

[0110] This application claims priority based on Japanese Patent Application No. 2023-169793, filed with the Japan Patent Office on September 29, 2023, the entire disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A negative-type photosensitive resin composition comprising a polyhydroxyamide compound containing a structural unit represented by the following formula (1), a crosslinking agent, and a photoacid generator. 【Chemistry 1】

2. The negative-type photosensitive resin composition according to claim 1, further comprising a basic compound.

3. The negative-type photosensitive resin composition according to claim 1, wherein the weight-average molecular weight of the polyhydroxyamide compound is 2,000 to 20,000.

4. A dry film comprising a resin layer formed from the negative-type photosensitive resin composition described in claim 1.

5. A cured product formed from the negative-type photosensitive resin composition described in claim 1 or the resin layer of the dry film described in claim 4.

6. An electronic component having the cured product described in claim 5.

7. The negative-type photosensitive resin composition according to claim 2, wherein the basic compound comprises one or more selected from diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, and N,N-dimethylethanolamine.

8. The negative-type photosensitive resin composition according to claim 1, wherein the weight-average molecular weight of the polyhydroxyamide compound is 2,000 to 15,000.

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