Epoxy resin, photosensitive resin composition, resist film, curable composition, and cured film

Abstract

To provide an epoxy resin capable of suppressing volatilization and sublimation of low-molecular-weight components during heat treatment, and producing a film exhibiting a high refractive index, a low extinction coefficient, and high etching resistance.SOLUTION: Provided is an epoxy resin having a structure represented by formula (1-3) at both ends.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an epoxy resin, a photosensitive resin composition, a resist film, a curable composition, and a cured film.

Background Art

[0002] In recent years, with the increasing integration and speed of LSIs, their pattern processing has been required to be increasingly finer. In photolithography using ArF excimer laser light (193 nm), by utilizing the optical characteristics of process materials and improving process equipment, it has become possible to exceed the inherent resolution limit derived from the wavelength of the light source.

[0003] In the field of photoresists, various methods for forming finer wiring patterns have been developed, and one of them is the multilayer resist method. In the multilayer resist method, one or more lower layer films are formed on a substrate, and after forming a resist pattern by ordinary photolithography thereon, the wiring pattern is processed and transferred to the substrate by dry etching.

[0004] One of the important members in the multilayer resist method is the lower layer film. As characteristics required for the lower layer film, film formability, high dry etching resistance, high refractive index, low attenuation coefficient, etc. are required. As a material for the lower layer film that satisfies such requirements, a novolak resin having a high aromatic ring concentration (for example, Patent Document 1) has been proposed, and a method for manufacturing a lower layer film using a cationic polymerizable compound and a photopolymerization initiator has also been proposed (Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When the borac resin of Patent Document 1 is used as the material of the lower layer film, when forming the lower layer film on the substrate, it is generally heat-treated at a high temperature of 170 to 200 °C. At this time, there is a problem that low molecular weight components contained in the lower layer film material volatilize or sublime, contaminating the peripheral equipment. In Patent Document 2, since heat treatment is not required for forming the lower layer film, the above problems of Patent Document 1 can be solved. However, since low molecular weight components volatilize or sublime during heat treatment (PEB, post-exposure bake) after resist exposure, the problem of contaminating the peripheral equipment itself cannot be solved. In addition, although the lower layer film is required to have a lower reflectance than the resist film, there is also a problem that the lower layer film of Patent Document 2 cannot meet this requirement.

[0007] The problem to be solved by the present invention is to provide an epoxy resin that can suppress the volatilization and sublimation of low molecular weight components during heat treatment and can produce a film exhibiting a high refractive index, a low attenuation coefficient, and high etching resistance.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that by using an epoxy resin having a specific structure, it is possible to suppress the volatilization and sublimation of low molecular weight components during heat treatment and to produce a film exhibiting a high refractive index, a low attenuation coefficient, and high etching resistance, thereby completing the present invention.

[0009] That is, the present invention relates to an epoxy resin having a repeating unit represented by the following general formula (1-1) and having a structure represented by the following general formula (1-2) at both ends.

[0010]

Chemical formula

[0011] According to the present invention, it is possible to provide an epoxy resin capable of suppressing the volatilization and sublimation of low molecular weight components during heat treatment and producing a film capable of exhibiting a high refractive index, a low attenuation coefficient and high etching resistance. [Brief Description of the Drawings]

[0012]

Figure 1

Figure 2

[0013] Hereinafter, an embodiment of the present invention will be described. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the range that does not impair the effects of the present invention.

[0014] [Epoxy Resin] The epoxy resin of the present invention has a repeating unit represented by the following general formula (1-1), and both ends have a structure represented by the following general formula (1-2). Here, "both ends" means both ends of the main chain (the longest molecular chain) of the epoxy resin.

[0015] [Chemical formula] (In the above general formulas (1-1) and (1-2), R 11 、R 12 、R 13 、R 14 and R 15 are each independently an alkylene group having 1 to 6 carbon atoms, R 21 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R 22 and R 23 are each independently an alkylene group having 1 to 6 carbon atoms, X 1 、X 2 and X 3 are each independently an alkyl group, an alkoxy group, an aryl group, an aralkyl group or a halogen atom, Y is an oxo group, * is a bond that binds to the repeating unit, a, b and c are each independently an integer of 0 to 5.)

[0016] In the epoxy resin of the present invention, both ends have a structure represented by the general formula (1-2), and the cyclic structure formed by R 22 and R 23 is flexible, so it is considered that the crystallinity of the epoxy resin is reduced and the coating property is improved. The structures represented by the general formula (1-2) may be the same or different from each other at both ends.

[0017] R 11 、R 12 、R 13 、R 14 and R15 The alkylene group having 1 to 6 carbon atoms is preferably an alkylene group having 1 to 3 carbon atoms, more preferably a methylene group.

[0018] R 21 The alkyl group having 1 to 5 carbon atoms is preferably an alkyl group having 1 to 3 carbon atoms.

[0019] R 22 and R 23 The alkylene group having 1 to 6 carbon atoms is preferably an alkylene group having 1 to 3 carbon atoms, more preferably a methylene group.

[0020] X 1 、X 2 and X 3 Examples of the alkyl group of X 1 , X 2 and X 3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a cyclohexyl group. The number of carbon atoms of the alkyl group is, for example, 1 to 9, preferably 1 to 3.

[0021] X 1 、X 2 and X 3 Examples of the alkoxy group of X 1 , X 2 and X 3 include a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group. The number of carbon atoms of the alkoxy group is, for example, 1 to 9, preferably 1 to 3.

[0022] X 1 、X 2 and X 3 Examples of the aryl group of X 1 , X 2 and X 3 include an aryl group having 6 to 14 carbon atoms forming a ring. The aryl group may have substituents such as the above-mentioned alkyl group, the above-mentioned alkoxy group, and a hydroxy group. Specific examples of the aryl group include a phenyl group, a hydroxyphenyl group, a dihydroxyphenyl group, a hydroxyalkoxyphenyl group, an alkoxyphenyl group, a tolyl group, a xylyl group, a naphthyl group, a hydroxynaphthyl group, and a dihydroxynaphthyl group.

[0023] X 1 、X 2 and X 3 The aralkyl group of X 1 , X 2 and X 3 means an alkyl group in which one or more hydrogen atoms of the alkyl group are substituted with an aryl group. Examples of the aryl group include the same aryl groups as described above. X 1 、X 2 and X 3 Specific examples of the aralkyl group of X 1 , X 2 and X 3 include phenylmethyl group, hydroxyphenylmethyl group, dihydroxyphenylmethyl group, tolylmethyl group, xylylmethyl group, naphthylmethyl group, hydroxynaphthylmethyl group, dihydroxynaphthylmethyl group, phenylethyl group, hydroxyphenylethyl group, dihydroxyphenylethyl group, tolylethyl group, xylylethyl group, naphthylethyl group, hydroxynaphthylethyl group, dihydroxynaphthylethyl group. The number of carbon atoms of the aralkyl group is, for example, 7 to 15, preferably 7 to 12.

[0024] X 1 、X 2 and X 3 Examples of the halogen atom of X 1 , X 2 and X 3 include fluorine atom, chlorine atom, bromine atom and the like.

[0025] a, b and c are preferably integers from 0 to 2, more preferably 0 or 1.

[0026] The structure represented by the general formula (1-2) is preferably the structure represented by the following general formula (1-3).

[0027] [Chemical formula] (In the general formula (1-3), R 13 、R 14 、R 15 、R 22 and R 23 are the same as those in the general formula (1-2).)

[0028] Specific examples of the epoxy resin of the present invention include epoxy resins represented by the following general formula (1).

[0029]

Chemical formula

[0030] The weight average molecular weight of the epoxy resin of the present invention is, for example, 500 to 50,000, preferably 500 to 10,000, and more preferably 500 to 5,000. The weight average molecular weight of the epoxy resin of the present invention is measured by the method described in the examples.

[0031] [Method for producing epoxy resin] The epoxy resin of the present invention can be produced by reacting a dihydroxynaphthalene compound with an aldehyde compound in the presence of an alkali catalyst to obtain a dihydroxynaphthalene resin, and then reacting the dihydroxynaphthalene resin with epihalohydrin.

[0032] As the dihydroxynaphthalene compound, for example, compounds represented by the following general formula (A) can be used, and specific examples thereof include 2,7-dihydroxynaphthalene, methyl-2,7-dihydroxynaphthalene, ethyl-2,7-dihydroxynaphthalene, t-butyl-2,7-dihydroxynaphthalene, methoxy-2,7-dihydroxynaphthalene, ethoxy-2,7-dihydroxynaphthalene, and the like. The dihydroxynaphthalene compound used may be a single species or a combination of two or more species.

[0033]

Chemical formula

[0034] Examples of the alkali catalyst include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metals such as metallic sodium and metallic lithium; alkali metal hydrides such as sodium hydride; and alkali metal carbonates such as sodium carbonate and potassium carbonate. The alkali catalyst used may be a single species or a combination of two or more species.

[0035] The amount of the alkali catalyst used is preferably 0.9 to 5 moles, more preferably 1 to 5 moles, and even more preferably 2 to 5 moles, per mole of the dihydroxynaphthalene compound. To obtain the epoxy resin of the present invention having the structure represented by the general formula (1-2) at both ends, an amount different from what is referred to as a "catalytic amount" is used. By using this amount, it is presumed that the electron density at the ortho position after the proton is removed from the hydroxyl group of the dihydroxynaphthalene compound becomes higher, promoting the formation of the cyclic structure.

[0036] The aldehyde compound is, for example, a compound represented by R 21 CHO (R 21 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). Specific examples thereof include formaldehyde, acetaldehyde, propionaldehyde, n-butylaldehyde, t-butylaldehyde, pentylaldehyde, and the like. Among the above aldehyde compounds, formaldehyde is preferred, and this formaldehyde may be used in the form of formalin in an aqueous solution state or as paraformaldehyde in a solid state. The aldehyde compound used may be a single species or a combination of two or more species.

[0037] R in the general formulas (1-1) and (1-2) 21 , R 22 , R 23 and R 24 are structures derived from the aldehyde compound.

[0038] The amount of the aldehyde compound used is preferably 0.5 to 4 moles, more preferably 0.6 to 4 moles, and even more preferably more than 2.0 moles, per mole of the dihydroxynaphthalene compound. Since the structure represented by the general formula (1-2) is formed by the reaction of two aldehyde compounds, it is preferable to use the aldehyde compound in the above amount in order to have the structure represented by the general formula (1-2) at both ends.

[0039] When the reaction between the dihydroxynaphthalene compound and the aldehyde compound is carried out by heating and stirring in the presence of an alkali catalyst, the heating temperature may be set in the range of 20 to 150 °C, and the reaction time may be in the range of, for example, 1 to 10 hours. In addition, a known method can be adopted for the post-treatment after the reaction.

[0040] The reaction between the dihydroxynaphthalene compound and the aldehyde compound is preferably carried out in an organic solvent, such as monoalcohols such as methanol, ethanol, and propanol; polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, and glycerin; glycol ethers such as 2-ethoxyethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, and ethylene glycol monophenyl ether; cyclic ethers such as 1,3-dioxane, 1,4-dioxane, and tetrahydrofuran; glycol esters such as ethylene glycol acetate; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. These solvents may be used alone or as a mixed solvent of two or more kinds.

[0041] The epoxy resin of the present invention can be obtained by reacting a dihydroxynaphthalene resin with epihalohydrin.

[0042] Examples of the epihalohydrin include epichlorohydrin, epibromohydrin, β-methylepichlorohydrin, etc., and epichlorohydrin is preferred because of its good reactivity. The epihalohydrin used may be a single species or a combination of two or more species.

[0043] The amount of the epihalohydrin used is preferably 1 to 10 moles, more preferably 2 to 5 moles, per mole of the phenolic hydroxyl group in the dihydroxynaphthalene resin.

[0044] The reaction between the dihydroxynaphthalene resin and the epihalohydrin is preferably carried out in the presence of an alkali catalyst, and the same alkali catalyst as described above can be used. The amount of the alkali catalyst used in the reaction between the dihydroxynaphthalene resin and the epihalohydrin may be a normal catalyst amount.

[0045] The reaction between the dihydroxynaphthalene resin and the epihalohydrin is preferably carried out in an organic solvent, and the same organic solvent as described above can be used.

[0046] Known reaction conditions can be adopted for the reaction between the dihydroxynaphthalene resin and the epihalohydrin, and known methods can also be adopted for the post-treatment after the reaction.

[0047] When a dihydroxynaphthalene resin is reacted with an epihalohydrin, in addition to the epoxy resin of the present invention, an epoxy compound represented by the following general formula (2) (hereinafter sometimes referred to as "the epoxy compound of the present invention") is also obtained simultaneously.

[0048]

Chemical formula

[0049] The epoxy compound of the present invention is preferably contained in a composition containing the epoxy resin of the present invention described below.

[0050] The epoxy compound represented by the general formula (2) is preferably an epoxy compound represented by the following general formula (2-1).

[0051] [Chemical formula] (In the general formula (2-1), R 14 、R 15 、R 16 、R 17 、R 22 、R 23 、R 24 and R 25 are the same as those in the general formula (2).)

[0052] [Photosensitive resin composition] The photosensitive resin composition of the present invention contains the epoxy resin of the present invention and a photosensitizer, and preferably contains the epoxy resin of the present invention, the epoxy compound of the present invention and a photosensitizer. Hereinafter, components other than the epoxy resin and the epoxy compound of the present invention contained in the photosensitive resin composition of the present invention will be described.

[0053] Examples of the photosensitizer include compounds having a quinonediazide group. Specific examples of the compounds having a quinonediazide group include, for example, complete ester compounds, partial ester compounds, amidated products, or partial amidated products of aromatic (poly)hydroxy compounds and sulfonic acids having a quinonediazide group such as naphthoquinone-1,2-diazide-5-sulfonic acid, naphthoquinone-1,2-diazide-4-sulfonic acid, and orthoanthraquinonediazide sulfonic acid.

[0054] Examples of the aromatic (poly)hydroxy compounds include polyhydroxybenzophenone compounds such as 2,3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,6-trihydroxybenzophenone, 2,3,4-trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,3',4,4',6-pentahydroxybenzophenone, 2,2',3,4,4'-pentahydroxybenzophenone, 2,2',3,4,5-pentahydroxybenzophenone, 2,3',4,4',5',6-hexahydroxybenzophenone, and 2,3,3',4,4',5'-hexahydroxybenzophenone;

[0055] Bis(2,4-dihydroxyphenyl)methane, bis(2,3,4-trihydroxyphenyl)methane, 2-(4-hydroxyphenyl)-2-(4'-hydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(2',4'-dihydroxyphenyl)propane, 2-(2,3,4-trihydroxyphenyl)-2-(2',3',4'-trihydroxyphenyl)propane, 4,4'-{1-[4-[2-(4-hydroxyphenyl)-2-propyl]phenyl]ethylidene}bisphenol, 3,3'-dimethyl-{1-[4-[2-(3-methyl-4-hydroxyphenyl)-2-propyl]phenyl]ethylidene}bisphenol and other bis[(poly)hydroxyphenyl]alkane compounds;

[0056] Tris(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-3,4-dihydroxyphenylmethane and other tris(hydroxyphenyl)methane compounds or their methyl-substituted derivatives;

[0057] Bis(3-cyclohexyl-4-hydroxyphenyl)-3-hydroxyphenylmethane, bis(3-cyclohexyl-4-hydroxyphenyl)-2-hydroxyphenylmethane, bis(3-cyclohexyl-4-hydroxyphenyl)-4-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-2-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-4-hydroxyphenylmethane, bis(3-cyclohexyl-2-hydroxyphenyl)-3-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-3-methylphenyl)-4-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-3-methylphenyl)-3-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-3-methylphenyl)-2-hydroxyphenylmethane, bis(3-cyclohexyl-2-hydroxyphenyl)-4-hydroxy Examples thereof include bis(cyclohexylhydroxyphenyl)(hydroxyphenyl)methane compounds such as bis(3-cyclohexyl-2-hydroxyphenyl)-4-hydroxyphenylmethane, bis(3-cyclohexyl-2-hydroxyphenyl)-2-hydroxyphenylmethane, bis(5-cyclohexyl-2-hydroxy-4-methylphenyl)-2-hydroxyphenylmethane, bis(5-cyclohexyl-2-hydroxy-4-methylphenyl)-4-hydroxyphenylmethane, and methyl-substituted products thereof.

[0058] The photosensitizer may be used alone or in combination of two or more.

[0059] The blending amount of the photosensitizer is preferably in a ratio of 5 to 50 parts by mass with respect to 100 parts by mass in total of the resin solid content of the photosensitive resin composition, so as to obtain a photosensitive resin composition excellent in photosensitivity.

[0060] The photosensitive resin composition of the present invention may contain another resin (X) other than the epoxy resin of the present invention. As the resin (X), those soluble in an alkaline developer or those dissolved in an alkaline developer by being used in combination with additives such as an acid generator can be used.

[0061] Examples of the resin (X) include a phenol resin (X-1); a homopolymer or copolymer (X-2) of a hydroxy group-containing styrene compound such as p-hydroxystyrene and p-(1,1,1,3,3,3-hexafluoro-2-hydroxypropyl)styrene; a modified product (X-3) obtained by modifying the hydroxy group of the above (X-1) or (X-2) with an acid-decomposable group such as a t-butoxycarbonyl group or a benzyloxycarbonyl group; a homopolymer or copolymer (X-4) of (meth)acrylic acid; an alternating copolymer (X-5) of an alicyclic polymerizable monomer such as a norbornene compound and a tetracyclododecene compound with maleic anhydride or maleimide, and the like.

[0062] When using the resin (X), the blending ratio of the epoxy resin of the present invention and the resin (X) can be arbitrarily adjusted according to the desired use. The proportion of the epoxy resin of the present invention in the total of the resin components in the composition is preferably, for example, 60% by mass or more. The proportion of the epoxy resin of the present invention in the composition is preferably 70% by mass or more, 80% by mass or more, and 90% by mass or more in order of the total of the resin components.

[0063] The photosensitive resin composition of the present invention may contain a surfactant for the purpose of improving film-forming properties, pattern adhesion, and reducing development defects when used in resist applications.

[0064] Examples of surfactants include polyoxyethylene alkyl ether compounds such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl allyl ether compounds such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers, sorbitan fatty acid ester compounds such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan fatty acid ester compounds such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate, etc. nonionic surfactants; fluorosurfactants having a fluorine atom in the molecular structure, such as a copolymer of a polymerizable monomer having a fluoroaliphatic group and [poly(oxyalkylene)](meth)acrylate; silicone surfactants having a silicone structural moiety in the molecular structure, etc. The surfactant may be used alone or in combination of two or more.

[0065] The content of the surfactant is preferably used in the range of 0.001 to 2 parts by mass with respect to 100 parts by mass in total of the resin solids in the photosensitive resin composition of the present invention.

[0066] The photosensitive resin composition of the present invention may further contain various additives such as dyes, fillers, crosslinking agents, and dissolution accelerators. Known ones can be used as these additives.

[0067] The photosensitive resin composition of the present invention may be used by dissolving the epoxy resin of the present invention in an organic solvent. The epoxy resin of the present invention is dissolved in an organic solvent to form a resist resin composition, which may be used directly as a positive resist solution, or a positive resist film may be used which is obtained by applying the resist resin composition in the form of a film and removing the solvent. Examples of the support film used when using it as a resist film include synthetic resin films such as polyethylene, polypropylene, polycarbonate, and polyethylene terephthalate. The support film may be a single-layer film or a laminated film. Further, the surface of the support film may be corona-treated or coated with a release agent.

[0068] The organic solvent used in the photosensitive resin composition of the present invention is not particularly limited. For example, alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether; dialkylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; alkylene glycol alkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; ketone compounds such as acetone, methyl ethyl ketone, cyclohexanone, and methyl amyl ketone; cyclic ethers such as dioxane; and ester compounds such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl formate, ethyl acetate, butyl acetate, methyl acetoacetate, and ethyl acetoacetate can be mentioned. The organic solvent may be used alone or in combination of two or more.

[0069] The photosensitive resin composition of the present invention can be prepared by blending the above components and mixing them using a stirrer or the like. When the photosensitive resin composition contains a filler or a pigment, it can be prepared by dispersing or mixing using a dispersing device such as a dissolver, a homogenizer, or a three-roll mill.

[0070] In the photolithography method using the photosensitive composition of the present invention as a resist resin composition, for example, the resist resin composition is applied onto an object to be subjected to silicon substrate photolithography and prebaked under temperature conditions of 60 to 150°C. The coating method at this time may be any method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor blade coating.

[0071] Regarding the formation of the resist pattern, since the resist resin composition of the present embodiment is a positive type, the target resist pattern is exposed through a predetermined mask, and the exposed portion is dissolved in an alkaline developer to form the resist pattern. Since the resist resin composition has high alkali solubility in the exposed portion and high alkali resistance in the non-exposed portion, it is possible to form a resist pattern with excellent resolution.

[0072] [Curable resin composition] The curable resin composition of the present invention contains the epoxy resin of the present invention and a curing agent, and preferably contains the epoxy resin of the present invention, the epoxy compound of the present invention, and a curing agent. Hereinafter, components other than the epoxy resin of the present invention and the epoxy compound of the present invention contained in the curable resin composition of the present invention will be described.

[0073] The curing agent is not particularly limited as long as it is a compound that can cause a curing reaction with the epoxy resin of the present invention, and various compounds can be used. For example, melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, resol resins, epoxy resins (other than the epoxy resin of the present invention), isocyanate compounds, azide compounds, compounds containing a double bond such as an alkenyl ether group, acid anhydrides, and oxazoline compounds can be mentioned.

[0074] Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, and a compound in which 1 to 6 methylol groups of hexamethylol melamine are acyloxymethylated.

[0075] Examples of the guanamine compound include tetramethylol guanamine, tetramethoxymethyl guanamine, tetramethoxymethyl benzoguanamine, a compound in which 1 to 4 methylol groups of tetramethylol guanamine are methoxymethylated, tetramethoxyethyl guanamine, tetraacyloxy guanamine, and a compound in which 1 to 4 methylol groups of tetramethylol guanamine are acyloxymethylated.

[0076] Examples of the glycoluril compound include 1,3,4,6 - tetrakis(methoxymethyl) glycoluril, 1,3,4,6 - tetrakis(butoxymethyl) glycoluril, and 1,3,4,6 - tetrakis(hydroxymethyl) glycoluril.

[0077] Examples of the urea compound include 1,3 - bis(hydroxymethyl) urea, 1,1,3,3 - tetrakis(butoxymethyl) urea, and 1,1,3,3 - tetrakis(methoxymethyl) urea.

[0078] Examples of the resol resin include polymers obtained by reacting phenolic hydroxyl group - containing compounds such as phenol, alkylphenols such as cresol and xylenol, phenylphenol, resorcinol, biphenyl, bisphenols such as bisphenol A and bisphenol F, naphthol, dihydroxynaphthalene with aldehyde compounds under alkaline catalyst conditions.

[0079] Examples of the epoxy resin include diglycidyl oxy naphthalene, phenol novolak type epoxy resin, cresol novolak type epoxy resin, naphthol novolak type epoxy resin, naphthol-phenol co-condensed novolak type epoxy resin, naphthol-cresol co-condensed novolak type epoxy resin, phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, 1,1-bis(2,7-diglycidyl oxy-1-naphthyl) alkane, naphthylene ether type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phosphorus atom-containing epoxy resin, and polyglycidyl ether of a co-condensate of a phenol hydroxyl group-containing compound and an alkoxy group-containing aromatic compound.

[0080] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0081] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidene bisazide, and 4,4'-oxy bisazide.

[0082] Examples of the compound containing a double bond such as an alkenyl ether group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0083] Examples of the acid anhydride include aromatic acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, 3,3’,4,4’-benzophenone tetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, 4,4’-(isopropylidene) diphthalic anhydride, 4,4’-(hexafluoroisopropylidene) diphthalic anhydride; alicyclic carboxylic acid anhydrides such as tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenyl succinic anhydride, trialkyltetrahydrophthalic anhydride, etc.

[0084] The curing agent may be used alone or in combination of two or more kinds.

[0085] The content of the curing agent is preferably in the range of 0.5 to 50 parts by mass with respect to 100 parts by mass of the epoxy resin of the present invention, since a composition excellent in curability can be obtained.

[0086] The curable resin composition of the present invention may contain another resin (Y) other than the epoxy resin of the present invention. Examples of the resin (Y) include various novolak resins, addition polymerization resins of alicyclic diene compounds such as dicyclopentadiene and phenolic compounds, modified novolak resins of phenolic hydroxyl group-containing compounds and alkoxy group-containing aromatic compounds, phenol aralkyl resins (zairok resins), naphthol aralkyl resins, trimethylolmethane resins, tetraphenylol ethane resins, biphenyl-modified phenolic resins, biphenyl-modified naphthol resins, aminotriazine-modified phenolic resins, and various vinyl polymers.

[0087] When using the resin (Y), the blending ratio of the epoxy resin of the present invention and the resin (Y) can be arbitrarily adjusted according to the desired application. For example, the ratio of the epoxy resin of the present invention in the total resin components in the composition is preferably 60% by mass or more. The ratio of the epoxy resin of the present invention in the composition is preferably 70% by mass or more, 80% by mass or more, 90% by mass or more in order of the total of the resin components.

[0088] The cured product of the curable composition of the present invention can be suitably used as a resist underlayer film and a resist permanent film. When the curable composition of the present invention is used for a resist underlayer film (BARC film) application, in addition to the epoxy resin and curing agent of the present invention, other resins (Y), surfactants, dyes, fillers, crosslinking agents, dissolution accelerators, and other various additives may be added as necessary, and the composition can be dissolved in an organic solvent to obtain a composition for a resist underlayer film.

[0089] The organic solvent used for the composition for a resist underlayer film is not particularly limited. For example, alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether; dialkylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; alkylene glycol alkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; ketone compounds such as acetone, methyl ethyl ketone, cyclohexanone, and methyl amyl ketone; cyclic ethers such as dioxane; and ester compounds such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl formate, ethyl acetate, butyl acetate, methyl acetoacetate, and ethyl acetoacetate can be mentioned. The organic solvent may be used alone or in combination of two or more.

[0090] The composition for the resist underlayer film can be prepared by blending the above components and mixing them using a stirrer or the like. When the composition for the resist underlayer film contains a filler or a pigment, it can be prepared by dispersing or mixing using a dispersing device such as a dissolver, a homogenizer, or a three-roll mill.

[0091] To form a resist underlayer film from the composition for the resist underlayer film, for example, there is a method of applying the above-described composition for the resist underlayer film onto an object for photolithography such as a silicon substrate, drying it under temperature conditions of 100 to 200°C, and then further heat-curing it under temperature conditions of 250 to 400°C. Next, a normal photolithography operation is performed on this underlayer film to form a resist pattern, and a resist pattern by the multilayer resist method can be formed by performing a dry etching treatment with a halogen-based plasma gas or the like.

[0092] When the curable composition of the present invention is used for a resist permanent film application, in addition to the epoxy resin and curing agent of the present invention, other resins (Y), surfactants, dyes, fillers, crosslinking agents, dissolution accelerators, and other additives can be added as necessary, and dissolved in an organic solvent to obtain a composition for a resist permanent film. The organic solvent used here may be the same as the organic solvent used in the composition for the resist underlayer film.

[0093] The method of photolithography using the composition for the resist permanent film is, for example, dissolving and dispersing the resin component and the additive component in an organic solvent, applying it onto an object for silicon substrate photolithography, and prebaking it under temperature conditions of 60 to 150°C. The coating method at this time may be any method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor blade coating. Next, when the composition for the resist permanent film is a positive type, the target resist pattern is exposed through a predetermined mask, and the exposed portion is dissolved in an alkaline developer to form a resist pattern.

[0094] The permanent film composed of the resist permanent film composition can be suitably used, for example, in the field of semiconductor devices for solder resist, package materials, underfill materials, package adhesive layers such as circuit elements, adhesive layers between integrated circuit elements and circuit boards, and in the field of thin film displays represented by LCD and OLED for thin film transistor protective films, liquid crystal color filter protective films, black matrices, spacers, etc.

Examples

[0095] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Note that the present invention is not limited to the following Examples. Also, in the Examples of the present application, “%” means “mass %”.

[0096] In the Examples of the present application, the weight average molecular weight of the compound is a value converted to polystyrene based on GPC measurement, and the measurement conditions are as follows.

[0097] (Gel Permeation Chromatography (GPC) Measurement Conditions) Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation Column: “Shodex KF802” (8.0 mm Ф × 300 mm) manufactured by Showa Denko KK + “Shodex KF802” (8.0 mm Ф × 300 mm) manufactured by Showa Denko KK + “Shodex KF803” (8.0 mm Ф × 300 mm) manufactured by Showa Denko KK + “Shodex KF804” (8.0 mm Ф × 300 mm) manufactured by Showa Denko KK Detector: RI (Differential Refractometer) Data processing: “GPC-8020 Model II Version 4.30” manufactured by Tosoh Corporation Column temperature: 40°C Developing solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Injection volume: 0.1 mL Sample: A 0.5 mass % tetrahydrofuran solution in terms of resin solid content filtered through a microfilter Standard sample: The following monodisperse polystyrene

[0098] (Polystyrene used) "A-500" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation

[0099] ( 13 C-NMR measurement) 13 The C-NMR spectrum was measured using "AL-400" manufactured by JEOL Ltd., and the structure analysis was performed by analyzing the Acetone-d6 solution of the sample. The following 13 shows the measurement conditions of the C-NMR spectrum. 13 C-NMR spectrum measurement conditions] Measurement mode: SGNNE (1H complete decoupling method with NOE elimination) Pulse angle: 45°C pulse Sample concentration: 30 wt% Number of integrations: 10,000 times

[0100] (FD-MS measurement) FD-MS was measured using a double-focusing mass spectrometer AX505H (FD505H) manufactured by JEOL Ltd.

[0101] (Synthesis Example 1: Synthesis of epoxy resin (A-1)) ​Into a 2,000 ml four-necked flask equipped with a thermometer, a cooling tube and a stirrer, 180 g (1.13 mol) of 2,7-dihydroxynaphthalene, 137 g (1.69 mol) of 37% aqueous formaldehyde solution, 288 g of isopropyl alcohol, and 197 g (1.69 mol) of 48% aqueous potassium hydroxide solution were charged, and then the mixture was stirred and reacted under reflux at 85 °C for 12 hours. After completion of the reaction, ethyl acetate and water were added, and liquid separation washing was performed 5 times. After the solvent was distilled off under reduced pressure from the remaining resin solution, vacuum drying was carried out to obtain 214 g of a light red powder phenolic resin (a-1).

[0102] Into a 2,000 ml four-necked flask equipped with a thermometer, a cooling tube and a stirrer, 120 g of the obtained phenolic resin (a-1), 830 g (8.97 mol) of epichlorohydrin, 12 g (0.15 mol) of 49% aqueous sodium hydroxide solution, 55 g of ion-exchanged water were charged, and 221 g of isopropanol was added and dissolved. Then, the temperature was raised to 60 °C, 64 g (0.78 mol) of 49% aqueous sodium hydroxide solution was added over 30 minutes, and after further stirring for 1 hour, washing with water was carried out. After repeating this operation once more, the organic layer was recovered, and the solvent was distilled off under reduced pressure at 150 °C to obtain a powdery epoxy resin (A-1).

[0103] When the weight average molecular weight of the obtained epoxy resin (A-1) was measured, it was 1,745. Also, when FD-MS measurement was performed on the epoxy resin (A-1), peaks were confirmed at 752 and 1320 in the FD-MS spectrum. Separately 13 C-NMR measurement was also carried out, and it was confirmed that the epoxy resin (A-1) is an epoxy composition (A-1) which is a mixture of an epoxy resin represented by the following general formula (A-1-1) and an epoxy compound represented by the following general formula (A-1-2). The above 13 The results of the above C-NMR measurement are shown in Figure 1, and the results of the above FD-MS measurement are shown in Figure 2.

[0104]

Chemical formula

[0105] (Synthesis Example 2: Synthesis of Epoxy Resin (A-2)) Using 180 g (1.13 mol) of 2,7-dihydroxynaphthalene, 182 g (2.25 mol) of 37% aqueous formaldehyde solution, 288 g of isopropyl alcohol, and 263 g (2.25 mol) of 48% aqueous potassium hydroxide solution, 223 g of powdery phenolic resin (a-2) was obtained in the same manner as the synthesis of the phenolic resin in Synthesis Example 1.

[0106] Using 15 g of the obtained phenolic resin (a-2), 104 g (1.12 mol) of epichlorohydrin, 2.50 g (0.01 mol) of 20% aqueous sodium hydroxide solution, 7 g of ion-exchanged water, and 28 g of isopropanol, and setting the addition amount of 20% aqueous sodium hydroxide solution to 31 g (0.16 mol), powdery epoxy resin (A-2) was obtained in the same manner as the synthesis of the epoxy resin in Synthesis Example 1.

[0107] When the weight average molecular weight of the obtained epoxy resin (A-2) was measured, it was 954. Also, for epoxy resin (A-2), FD-MS measurement and 13 C-NMR measurement were performed, and it was confirmed that epoxy resin (A-2) is an epoxy composition (A-2) which is a mixture of the same epoxy resin and epoxy compound as in Synthesis Example 1.

[0108] (Synthesis Example 3: Synthesis of Epoxy Resin (A-3)) Using 180 g (1.13 mol) of 2,7-dihydroxynaphthalene, 365 g (4.49 mol) of 37% aqueous formaldehyde solution, 288 g of isopropyl alcohol, and 525 g (4.49 mol) of 48% aqueous potassium hydroxide solution, 221 g of powdery phenolic resin (a-3) was obtained in the same manner as the synthesis of the phenolic resin in Example 1.

[0109] 15 g of the obtained phenolic resin (a-3), 104 g (1.12 mol) of epichlorohydrin, 2.50 g (0.01 mol) of 20% aqueous sodium hydroxide solution, 7 g of ion-exchanged water, and 28 g of isopropanol were used. Except that the addition amount of the 20% aqueous sodium hydroxide solution was 31 g (0.16 mol), in the same manner as the synthesis of the epoxy resin in Synthesis Example 1, a powdery epoxy resin (A-3) was obtained.

[0110] When the weight average molecular weight of the obtained epoxy resin (A-3) was measured, it was 954. Also, for the epoxy resin (A-3), FD-MS measurement and 13 C-NMR measurement were performed, and it was confirmed that the epoxy resin (A-3) was an epoxy composition (A-3) which is a mixture of the same epoxy resin and epoxy compound as in Synthesis Example 1.

[0111] (Synthesis Example 4: Synthesis of Epoxy Resin (A-4)) Into a flask equipped with a thermometer, a dropping funnel, a condenser, and a stirrer, 150 g (0.94 mol) of 2,7-dihydroxynaphthalene, 84 g (1.03 mol) of 37% aqueous formaldehyde solution, 200 g of isopropyl alcohol, and 32 g (0.27 mol) of 48% aqueous potassium hydroxide solution were charged, and stirred while blowing nitrogen at room temperature. Then, the temperature was raised to 85 °C and stirred for 12 hours. After completion of the reaction, it was cooled to 40 °C, 720 g (7.78 mol) of epichlorohydrin was added dropwise over 1 hour, and after further stirring for 1 hour, it was washed with water. Next, the temperature was raised to 60 °C, 52 g (0.64 mol) of 49% aqueous sodium hydroxide solution was added over 30 minutes, and after further stirring for 1 hour, it was washed with water. After repeating this operation once more, the organic layer was recovered, and the solvent was distilled off under reduced pressure at 150 °C to obtain a powdery epoxy resin (A-4) powder.

[0112] When the weight average molecular weight of the obtained epoxy resin (A-4) was measured, it was 832. Also, for the epoxy resin (A-4), FD-MS measurement and 13When the C-NMR measurement was performed, it was confirmed that the epoxy resin (A-4) was an epoxy composition (A-4) which is a mixture of the same epoxy resin and epoxy compound as in Synthesis Example 1.

[0113] (Synthesis Example 5: Synthesis of Epoxy Resin (A-5)) Into a flask equipped with a thermometer, a dropping funnel, a fractionating tube, and a stirrer, 150 g (0.94 mol) of 2,7-dihydroxynaphthalene, 58 g (0.71 mol) of 37% aqueous formaldehyde solution, 200 g of isopropyl alcohol, and 3.5 g (0.04 mol) of 49% aqueous sodium hydroxide solution were charged, and the mixture was stirred while blowing nitrogen at room temperature. Then, the temperature was raised to 78 °C and stirred for 2 hours. After completion of the reaction, the mixture was cooled to 40 °C, 732 g (7.91 mol) of epichlorohydrin, 20 g of ion-exchanged water, and 24 g (0.29 mol) of 49% aqueous sodium hydroxide solution were added, stirred for 2 hours, and then washed with water. This operation was repeated once more, and then the temperature was raised to 60 °C. After the temperature rise, 57 g (0.70 mol) of 49% aqueous sodium hydroxide solution was added over 30 minutes, stirred for 1 hour, and then washed with water. After repeating this operation once more, the organic layer was recovered, and the solvent was distilled off under reduced pressure at 150 °C to obtain a powdery epoxy resin (A-5) powder.

[0114] When the weight average molecular weight of the obtained epoxy resin (A-5) was measured, it was 574. Also, for the epoxy resin (A-5), FD-MS measurement and 13 When the C-NMR measurement was performed, it was confirmed that the epoxy resin (A-5) was an epoxy composition (A-5) which is a mixture of the same epoxy resin and epoxy compound as in Synthesis Example 1.

[0115] (Synthesis Comparative Example 1: Preparation of Epoxy Resin (A'-1)) For comparison, N-770 (manufactured by DIC Corporation), a phenol novolac type epoxy resin, was prepared as an epoxy composition (A'-1).

[0116] (Synthesis Comparative Example 2: Synthesis of Epoxy Resin (A'-2)) Into a 2,000 ml four-necked flask equipped with a thermometer, a cooling tube and a stirrer, 240 g (1.50 mol) of 2,7-dihydroxynaphthalene, 85 g (1.05 mol) of 37% aqueous formaldehyde solution, 376 g of isopropyl alcohol, and 88 g (1.05 mol) of 48% aqueous potassium hydroxide solution were charged, and then the mixture was stirred and reacted under reflux at 75 °C for 2 hours. After the reaction was completed, ethyl acetate and water were added, and liquid separation washing was performed 5 times. After the solvent was distilled off under reduced pressure from the remaining resin solution, vacuum drying was carried out to obtain 245 g of phenol resin (a'-2).

[0117] To a 2,000 ml four-necked flask equipped with a thermometer, a cooling tube and a stirrer, 84 g of the obtained phenol resin (a'-2), 463 g (5.0 mol) of epichlorohydrin, and 53 g of n-butanol were added and dissolved. Then, the temperature was raised to 50 °C, 220 g (1.10 mol) of 49% by mass aqueous sodium hydroxide solution was added over 3 hours, and after stirring for another 1 hour, washing with water was performed. After repeating this operation once more, the organic layer was recovered, and the solvent was distilled off under reduced pressure at 150 °C to obtain powdery epoxy resin (A'-2).

[0118] When the obtained epoxy resin (A'-2) was evaluated in the same manner as in Synthesis Example 1, it was confirmed that, unlike the result of Synthesis Example 1, it was an epoxy resin composition that was a mixture of a compound represented by the following general formula (A'-2-1) and a compound represented by the following general formula (A'-2-2).

[0119] [Chemical formula]

[0120] (Examples 1-5 and Comparative Examples 1-2: Evaluation of volatile component content and film-forming property) For the epoxy compositions of Synthesis Examples 1-5 and Synthesis Comparative Examples 1-2, the volatile component content and film-forming property were evaluated by the following method. The results are shown in Table 1.

[0121] (Volatile component content) 1.0 g of the epoxy composition was spread on a petri dish to make it flat. It was dried in a dryer at 200 °C for 1 hour to sufficiently volatilize moisture and residual solvents. After drying, it was heated in a 200 °C dryer for 1 hour, the weight loss amount before and after heating was measured, and the amount of volatile components was evaluated according to the following criteria. ○: Weight loss rate is less than 0.1% ×: Weight loss rate is 0.1% or more

[0122] (Film-forming property) An epoxy resin solution prepared by dissolving 1.0 g of the epoxy composition in 9.0 g of cyclohexanone was applied onto a 6-inch diameter silicon wafer at 1500 rpm for 30 seconds using a spin coater, and pre-baked on a hot plate at 120 °C for 60 seconds to form an epoxy film with a film thickness of about 300 nm. The presence or absence of striations on the surface of the obtained epoxy film was visually confirmed and evaluated according to the following criteria. Excellent: No striations were confirmed Good: Some striations were confirmed Bad: Many striations were confirmed

[0123]

Table 1

[0124] From the results in Table 1, it was confirmed that in the composition containing an epoxy resin having a specific cyclic structure at both ends, the volatilization and sublimation of low molecular weight components during heat treatment can be suppressed.

[0125] (Examples 6 - 10 and Comparative Examples 3 - 4: Preparation and evaluation of the composition for forming the lower layer film) 10 g of the epoxy composition shown in the table, 5.0 g of a photoacid generator solution (“CPI - 101A” manufactured by Sanshin Chemical Industry Co., Ltd.), and 0.1 g of a surfactant (“Megafac R - 41” manufactured by DIC Corporation) were dissolved in 90 g of cyclohexanone, and the resulting solution was precisely filtered to prepare a composition for forming the lower layer film. Regarding the obtained composition for forming the lower layer film, the lower layer film was formed by the following method, and the optical properties and etching resistance were evaluated. The results are shown in Table 2.

[0126] (Optical property evaluation) The composition for forming the lower layer film was applied onto a 6-inch diameter silicon wafer to a thickness of about 300 nm using a spin coater, and then pre-baked on a hot plate at 120 °C for 60 seconds. Next, the pre-baked film was irradiated with ghi rays at 1000 mJ / cm 2 using an exposure apparatus ("MultiLight" manufactured by USHIO INC.), and post-baked on a hot plate at 250 °C for 90 seconds to fabricate the lower layer film. Regarding the fabricated lower layer film, the refractive index (n value) and extinction coefficient (k value) at a wavelength of 193 nm were measured using a spectroscopic ellipsometer (VUV-VASE GEN-1 manufactured by J.A. Woollam). For the n value, those with a value of 1.48 or more were evaluated as "○", and those with a value less than 1.48 were evaluated as "×". For the k value, those with a value less than 0.25 were evaluated as "○", and those with a value of 0.25 or more were evaluated as "×".

[0127] (Etching resistance evaluation) The composition for forming the lower layer film was applied onto a 6-inch diameter silicon wafer to a thickness of about 700 nm at 1500 rpm for 30 seconds using a spin coater, and then pre-baked on a hot plate at 120 °C for 60 seconds. Next, the pre-baked film was irradiated with ghi rays at 1000 mJ / cm 2 using an exposure apparatus ("MultiLight" manufactured by USHIO INC.), and post-baked on a hot plate at 250 °C for 90 seconds to fabricate the lower layer film. Regarding the fabricated lower layer film, an etching treatment was performed using an etching apparatus ("EXAM" manufactured by SHINKO SEIMITSU CO., LTD.) under the conditions of CF4: 89 sccm, pressure: 2.0 Pa, RF power: 100 W, and treatment time: 180 seconds. The film thickness of the lower layer film before and after the etching treatment was measured to calculate the etching rate, and the etching resistance was evaluated according to the following criteria. ○: Etching rate less than 110 nm / min ×: Etching rate is 110 nm / min or more

[0128]

Table 2

[0129] From the results in Table 2, it was confirmed that the film using the composition containing the epoxy resin having specific cyclic structures at both ends was excellent in optical properties and excellent in etching resistance.

Claims

1. An epoxy resin having repeating units represented by the following general formula (1-1) and having structures represented by the following general formula (1-2) at both ends. 【Chemical 1】 (In the above general formulas (1-1) and (1-2), R １１ , R １２ , R １３ , R １４ and R １５ are each independently an alkylene group having 1 to 6 carbon atoms, R ２１ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ２２ and R ２３ each independently represents an alkylene group having 1 to 6 carbon atoms, X １ , X ２ and X ３ are each independently an alkyl group, an alkoxy group, an aryl group, an aralkyl group or a halogen atom, a, b, and c are each independently an integer from 0 to 4.)

2. The epoxy resin according to claim 1, wherein the structure represented by the general formula (1-2) is a structure represented by the following general formula (1-3). 【Chemical 2】 (In the above general formula (1-3), R １３ 、 R １４ 、 R １５ 、 R ２２ 、 R ２３ and R ２４ are the same as the general formula (1-2).)

3. A method for producing an epoxy resin, comprising reacting a dihydroxynaphthalene compound and an aldehyde compound in the presence of an alkali catalyst to prepare a dihydroxynaphthalene resin, and reacting the dihydroxynaphthalene resin with epihalohydrin, wherein 0.9 to 5 moles of the alkali catalyst is used per 1 mole of the dihydroxynaphthalene compound, and more than 2.0 moles to 4 moles of the aldehyde compound is used per 1 mole of the dihydroxynaphthalene compound.

4. The method for producing an epoxy resin according to claim 3, wherein 1 to 10 moles of the epihalohydrin is used per 1 mole of the phenolic hydroxyl group in the dihydroxynaphthalene resin.

5. The method for producing an epoxy resin according to claim 3 or 4, wherein the dihydroxynaphthalene compound is one or more selected from 2,7-dihydroxynaphthalene, methyl-2,7-dihydroxynaphthalene, ethyl-2,7-dihydroxynaphthalene, t-butyl-2,7-dihydroxynaphthalene, methoxy-2,7-dihydroxynaphthalene, and ethoxy-2,7-dihydroxynaphthalene.

6.

7. The aldehyde compound is R ２１ CHO (R ２１ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), and the method for producing an epoxy resin according to any one of claims 3 to 5. The epoxy resin according to claim 1 or 2, having a weight average molecular weight of 500 to 5,000.

8. An epoxy composition containing the epoxy resin according to claim 1 or 2 and an epoxy compound represented by the following general formula (2). (In the above general formula (2), [Chemical Formula 3] b, c, and d are each independently an integer from 0 to 4.) R １４ 、R １５ 、R １６ and R １７ are each independently an alkylene group having 1 to 6 carbon atoms, R ２２ 、 R ２３ 、 R ２４ and R ２５ are each independently an alkylene group having 1 to 6 carbon atoms, X ２ 、 X ３ and X ４ is each independently an alkyl group, an alkoxy group, an aryl group, an aralkyl group or a halogen atom,

9. A photosensitive resin composition containing the epoxy resin according to claim 1 or 2 or the epoxy composition according to claim 8, and a photosensitizer.

10. A resist film using the photosensitive resin composition according to claim 9.

11. A curable composition containing the epoxy resin according to claim 1 or 2 or the epoxy composition according to claim 8, and a curing agent.

12. A cured film of the curable composition according to claim 11. ​

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