JP4913143B2 - Photosensitive resin composition - Google Patents

Description

  The present invention relates to a chemically amplified negative-type thick film resist. More specifically, it is suitable for precision processing such as bump formation, metal post formation, wiring formation, etc. performed in the manufacture of MEMS parts, micromachine parts, μ-TAS (micro total analysis system) parts, microreactor parts, electronic parts, etc. The present invention relates to a photosensitive resin composition capable of alkali development.

  A device in which minute mechanical elements, electronic circuits, and optical elements are integrated is called a MEMS (micro electro mechanical system) or a micro machine, and many applications have been studied and put into practical use (see Non-Patent Document 1). Although these devices are small parts based on semiconductor manufacturing technology, they are generic names for devices that function in a complex and sophisticated manner. Microdevices such as various sensors, printer heads, disk heads, optical switches for communication, biochips, etc. It is an important part that holds the key to the system. In this field, unlike normal semiconductor manufacturing, a resist capable of patterning with a high aspect ratio (the aspect ratio means the height / width of the structure) is required.

  As a method for producing a high aspect ratio structure, a pattern forming method by X-ray lithography (see Non-Patent Document 2) of a photosensitive resin composition called “LIGA process” is often employed. However, the LIGA process requires an expensive X-ray device and has the disadvantage that it takes a long time to irradiate X-rays, and it is inexpensive because of demands for resource saving, energy saving, workability improvement, productivity improvement, etc. Therefore, the application of a highly productive UV (ultraviolet) lithography system is attracting attention.

  However, conventional positive resists based on the dinaphthoquinone-novolak reaction in UV lithography systems are not suitable for applications requiring thick films of 50 μm or more. There is a limit in increasing the thickness of the film because the dinaphthoquinone type (DNQ) photoreactant in the near-ultraviolet region wavelength (350 to 450 nm) generally used for resist exposure has a relatively high light absorption. . In the DNQ type photoresist, the side wall shape is not a straight shape but a slope shape due to a characteristic solubility difference between an exposed region and a non-exposed region in the developer. Light absorption reduces the irradiation intensity from the top to the bottom of the film, but if such light absorption is too high, the bottom of the resist will be underexposed compared to the top, so the sidewall shape will be sloped or distorted. It becomes a shape.

  On the other hand, a negative-type chemically amplified thick film resist composition comprising a polyfunctional bisphenol A novolak epoxy resin, a photocationic polymerization initiator and a propylene carbonate solution of aromatic sulfonium hexafluoroantimonate has a wavelength range of 350 to 450 nm. It is known to have very low light absorption. This resist composition is spin-coated or curtain-coated on various substrates, and then the solvent is volatilized by baking to form a solid photoresist layer having a thickness of 100 μm or more. Further, contact exposure, proximity exposure, projection Photolithographic processing is performed by irradiating near ultraviolet light through a photomask using various exposure methods such as exposure. Subsequently, a negative image of a high-resolution photomask can be formed on the substrate by immersing in a developing solution and dissolving the non-exposed areas, and a dry coating coated on a substrate such as a polyester film. An application such as a film resist is also disclosed (Patent Document 1). However, an organic solvent is used for the development of this composition, and development of a resist for forming a high aspect ratio that can be developed with an alkali is desired because of its influence on the environment. Patent Documents 2 and 3 disclose resist compositions that can be developed with an aqueous alkaline solution as a chemically amplified thick film resist. High aspect ratio can be achieved and it has excellent properties such as heat resistance and plating resistance, but storage stability is reduced due to the mixture of alkali-soluble groups and reactive crosslinking groups. Tend.

Published by Micromachine, Industrial Technology Service Center Co., Ltd. (2002) Polymer, 43, 564 (1994) U.S. Pat. No. 4,882,245 Japanese Patent No. 3698499 US Publication No. 20050147918

In a conventional photosensitive resin composition using a polyfunctional epoxy resin such as a novolac-type epoxy resin or an alkali-soluble epoxy compound, the sensitivity of the photocation polymerization initiator contained may be low, and thus a large amount of initiator may be contained. There is a problem that it is necessary or the mask pattern cannot be faithfully reproduced in a short time. Further, SbF ₆ ^- albeit at a relatively high sensitivity photo-cationic polymerization initiator containing, available from toxicity problems applications was also a problem limited. The present invention has been made in view of the above-described conventional circumstances, and its problem is to provide a photosensitive resin composition that can form a pattern with high resolution and high aspect ratio and is highly sensitive. It is in.

  In order to solve the above-mentioned problems, the present inventors have intensively experimented and studied about increasing the sensitivity and increasing the resolution of the photosensitive resin composition. As a result, if a photosensitive resin composition is prepared by combining a specific alkali-soluble epoxy compound and a specific photocationic polymerization initiator, and a resin pattern is formed using this photosensitive resin composition, high sensitivity can be obtained. Thus, it was found that a resin pattern having a high aspect ratio can be formed.

That is, the configuration of the present invention is as follows.
(1) Photocationic polymerization initiator (A) which is sulfonium tris (pentafluoroethyl) trifluorophosphate, an epoxy compound (a) having two or more epoxy groups in one molecule, and one or more in one molecule And an alkali-soluble epoxy compound (B) obtained by reacting a polybasic acid anhydride (c) with a reaction product (I) of the compound (b) having a carboxyl group and one or more hydroxyl groups. Photosensitive resin composition.
(2) The photosensitive resin composition according to the above (1), wherein the alkali-soluble epoxy compound (B) is represented by the following general formula (1).

（３）光カチオン重合開始剤（Ａ）が、下記式（２）で表される化合物（Ａ−１）である上記（１）又は（２）に記載の感光性樹脂組成物。(In the formula (1), m and n are each an average value and independently represent a real number of 0 or more, and the sum is a real number of 0 to 30. Also, D ₁ and D ₂ are the same. Or may be different and represents any group selected from the group consisting of the following groups:

(3) The photosensitive resin composition as described in said (1) or (2) whose photocationic polymerization initiator (A) is the compound (A-1) represented by following formula (2).

(4) The photosensitive resin composition as described in any one of said (1)-(3) containing a phenol resin (C).
(5) The photosensitive resin composition as described in any one of said (1)-(4) whose solid content concentration is 5 to 95 weight% in the photosensitive resin composition containing a solvent (D). .
(6) The photosensitive resin composition laminated body which pinched | interposed the photosensitive resin composition as described in any one of said (1)-(5) with the base material.
(7) A cured product comprising the photosensitive resin composition according to any one of (1) to (5) above.
(8) After drying the photosensitive resin composition layer obtained by applying the photosensitive resin composition according to any one of (1) to (5) on a desired support, A pattern forming method comprising exposing to a predetermined pattern, baking after exposure, developing the resin composition layer, and heat-treating the obtained resin pattern to obtain a cured resin pattern having a predetermined shape.
(9) The photosensitive resin composition layer remaining after the substrate is removed from the laminate described in (6) above is laminated on a desired support, and the photosensitive resin composition layer is formed into a predetermined pattern. A pattern forming method comprising exposing to light, baking after exposure, developing the resin composition, and heat-treating the obtained resin pattern to obtain a cured resin pattern having a predetermined shape.

The photosensitive resin composition of the present invention can form a pattern with a high aspect ratio by development with an alkaline aqueous solution. Furthermore, because of the high sensitivity, to be advantageous in the manufacturing process, SbF ₆ ^- as compared to the less toxic.

The present invention is described in detail below.
The photosensitive resin composition of the present invention contains a photocationic polymerization initiator (A) that is sulfonium tris (pentafluoroethyl) trifluorophosphate and an alkali-soluble epoxy compound (B) represented by the general formula (1). It is characterized by doing. According to the photosensitive resin composition, a resin pattern having high sensitivity and a high aspect ratio can be formed.

  The cationic photopolymerization initiator in the present invention generates cations upon irradiation with radiation such as excimer lasers such as ultraviolet rays, far ultraviolet rays, KrF and ArF, X-rays, and electron beams, and the cations can serve as polymerization initiators. A compound.

  The photocationic polymerization initiator (A) is sulfonium tris (pentafluoroethyl) trifluorophosphate.

  As the sulfonium of the cationic photopolymerization initiator, triphenylsulfonium, tri-p-tolylsulfonium, tri-o-tolylsulfonium, tris (4-methoxyphenyl) sulfonium, 1-naphthyldiphenylsulfonium, 2-naphthyldiphenylsulfonium, Tris (4-fluorophenyl) sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tris (4-hydroxyphenyl) sulfonium, 4- (phenylthio) phenyldiphenylsulfonium, 4- (p-tolylthio) phenyldi- p-tolylsulfonium, 4- (4-methoxyphenylthio) phenylbis (4-methoxyphenyl) sulfonium, 4- (phenylthio) phenylbis (4-fluorophenyl) sulfonium, -(Phenylthio) phenylbis (4-methoxyphenyl) sulfonium, 4- (phenylthio) phenyldi-p-tolylsulfonium, bis [4- (diphenylsulfonio) phenyl] sulfide, bis [4- (bis [4- (2 -Hydroxyethoxy) phenyl] sulfonio) phenyl] sulfide, bis (4- [bis (4-fluorophenyl) sulfonio] phenyl) sulfide, bis (4- [bis (4-methylphenyl) sulfonio] phenyl) sulfide, bis ( 4- [bis (4-methoxyphenyl) sulfonio] phenyl) sulfide, 4- (4-benzoyl-4-chlorophenylthio) phenylbis (4-fluorophenyl) sulfonium, 4- (4-benzoyl-4-chlorophenylthio) Phenyldiphenylsulfonium 4- (4-benzoylphenylthio) phenylbis (4-fluorophenyl) sulfonium, 4- (4-benzoylphenylthio) phenyldiphenylsulfonium, 4-isopropyl-4-oxo-10-thia-9,10-dihydroanthracene 2-yldi-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldiphenylsulfonium, 2-[(di-p-tolyl) sulfonio] thioxanthone, 2 -[(Diphenyl) sulfonio] thioxanthone, 4- [4- (4-tert-butylbenzoyl) phenylthio] phenyldi-p-tolylsulfonium, 4- [4- (4-tert-butylbenzoyl) phenylthio] phenyldiphenylsulfonium, 4- [4- (Ben Zoylphenylthio)] phenyldi-p-tolylsulfonium, 4- [4- (benzoylphenylthio)] phenyldiphenylsulfonium, 5- (4-methoxyphenyl) thiaanthrhenium, 5-phenylthiaanthrhenium, 5-tolylthia Triarylsulfonium such as anthrenium, 5- (4-ethoxyphenyl) thiaanthrhenium, 5- (2,4,6-trimethylphenyl) thiaanthrhenium; diphenylphenacylsulfonium, diphenyl-4-nitrophenacylsulfonium, diphenyl Diarylsulfonium such as benzylsulfonium, diphenylmethylsulfonium; phenylmethylbenzylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 4-methoxyphenylmethylbenzylsulfur 4-acetocarbonyloxyphenylmethylbenzylsulfonium, 2-naphthylmethylbenzylsulfonium, 2-naphthylmethyl (1-ethoxycarbonyl) ethylsulfonium, phenylmethylphenacylsulfonium, 4-hydroxyphenylmethylphenacylsulfonium, 4-methoxy Monoarylsulfonium such as phenylmethylphenacylsulfonium, 4-acetocarbonyloxyphenylmethylphenacylsulfonium, 2-naphthylmethylphenacylsulfonium, 2-naphthyloctadecylphenacylsulfonium, 9-anthracenylmethylphenacylsulfonium; dimethylphena Silsulfonium, phenacyltetrahydrothiophenium, dimethylbenzylsulfonium, benzyltetrahydride Thiophenium, etc. trialkyl sulfonium such as octadecyl methyl phenacyl sulfonium and the like. These cationic photopolymerization initiators may be used alone or in combination of two or more. These are described in the following documents.

  Regarding triarylsulfonium, U.S. Pat. No. 4,231,951, U.S. Pat. No. 4,256,828, JP-A-7-61964, JP-A-8-165290, JP-A-7-10914, JP-A-7-25922, JP-A-8- 27208, JP-A-8-27209, JP-A-8-165290, JP-A-8-301991, JP-A-9-143212, JP-A-9-278813, JP-A-10-7680, JP-A-10-287463. JP-A-10-245378, JP-A-8-157510, JP-A-10-204083, JP-A-8-245656, JP-A-8-157451, JP-A-7-324069, JP-A-9-268205. JP, 9-278935, JP 2001-288205, JP 11-80118, JP JP-A-10-182825, JP-A-10-330353, JP-A-10-152495, JP-A-5-239213, JP-A-7-333834, JP-A-9-12537, JP-A-8-325259, JP-A-8-160606. JP, 2000-186071 (US Pat. No. 6,368,769), etc .; Regarding diarylsulfonium, JP-A-7-300504, JP-A-64-45357, JP-A-64-29419, etc .; Monoarylsulfonium JP-A-6-345726, JP-A-8-325225, JP-A-9-118663 (US Pat. No. 6,097,753), JP-A-2-196812, JP-A-2-1470, and JP-A-2-196812. JP-A-3-237107, JP-A-3-17101, JP-A-6-22 No. 086, JP-A-10-152469, JP-A-7-300505, JP-A-2003-277353, JP-A-2003-277352, etc .; regarding trialkylsulfonium, JP-A-4-308563, JP-A-5-140210, JP-A-5-140209, JP-A-5-230189, JP-A-6-271532, JP-A-58-37003, JP-A-2-178303, JP-A-10-338688, JP-A-9-328506, JP-A-11-228534, JP-A-8-27102, JP-A-7-333834, JP-A-5-222167, JP-A-11-21307, JP-A-11-35613, US Pat. No. 6,031,014, etc. Has been.

  In particular, as the sulfonium of the photocationic polymerization initiator, triphenylsulfonium and 4- (phenylthio) phenyldiphenylsulfonium are more preferable, and 4- (phenylthio) phenyldiphenylsulfonium (A-1) represented by the above formula (2) is preferable. Most preferred.

  As the alkali-soluble epoxy compound (B) in the present invention, an epoxy compound (a) having two or more epoxy groups in one molecule and a compound having one or more carboxyl groups and one or more hydroxyl groups in one molecule An epoxy compound obtained by reacting the polybasic acid anhydride (c) with the reactant (I) of (b) can be preferably used.

  Here, as the epoxy compound (a), for example, novolak type epoxy resin, bisphenol type epoxy resin, trisphenol methane type epoxy resin, tris (2,3-epoxypropyl) isocyanurate, biphenyl diglycidyl ether, alicyclic epoxy Examples thereof include resins and copolymerization type epoxy resins.

  The novolak type epoxy resin can be obtained, for example, by reacting novolaks obtained by reacting phenols such as phenol, cresol, halogenated phenol and alkylphenol with formaldehyde in the presence of an acidic catalyst, and epichlorohydrin and / or methyl epichlorohydrin. And the like. Examples of such an epoxy resin include Nippon Kayaku Co., Ltd., EOCN-103, EOCN-104S, EOCN-102, EOCN-1027, EOCN-4400H, EPPN-201, BREN-S; Commercial products are available as DEN-431, DEN-439; Dainippon Ink & Chemicals, N-730, N-770, N-865, N-665, N-673, VH-4150, and the like. Examples of the bisphenol type epoxy resin include those obtained by reacting bisphenols such as bisphenol A, bisphenol F, bisphenol S, and tetrabromobisphenol A with epichlorohydrin and / or methyl epichlorohydrin, and diglycidyl ether of bisphenol A or bisphenol F. And those obtained by reacting a condensate of bisphenols with epichlorohydrin and / or methyl epichlorohydrin. Examples of such epoxy resins include Epicoat 1004, Epicoat 1002, manufactured by Yuka Shell Epoxy Co., Ltd. Commercial products are available as Epicoat 4002, Epicoat 4004, and the like. Examples of the trisphenol methane type epoxy resin include those obtained by reacting trisphenol methane, tris-resole methane and the like with epichlorohydrin and / or methyl epichlorohydrin, and such an epoxy resin includes Nippon Kayaku ( Co., Ltd., EPPN-501, EPPN-502, etc. Examples of the alicyclic epoxy resin include Daicel Chemical Industries, Ltd., Celoxide 2021, Yuka Shell Epoxy, E-1031S, Nippon Soda Co., Ltd., EPB-13, EPB-27, and Daicel Chemical. Commercial products such as EHPE3150 manufactured by Kogyo Co., Ltd. are available. Examples of the copolymer type epoxy resin include CP-50M and CP-50S manufactured by Nippon Oil & Fats Co., Ltd., which are copolymers of glycidyl methacrylate, styrene, and methylstyrene, or copolymers of glycidyl methacrylate and cyclohexylmaleimide. Etc. In addition, it is also possible to use epoxy compounds having a special structure such as Mitsui Petrochemical Co., Ltd., Epomic VG-3101.

  Specific examples of the compound (b) include polyhydroxymonocarboxylic acids such as dimethylolpropionic acid, dimethylolacetic acid, dimethylolbutyric acid, dimethylolvaleric acid, dimethylolcaproic acid, hydroxypivalic acid, p-hydroxybenzoic acid and the like. And monohydroxy monocarboxylic acids. Two or more of these may be used in combination.

  The reaction between the epoxy compound (a) and the compound (b) having one or more carboxyl groups and one or more hydroxyl groups in one molecule is a compound with respect to 1 equivalent of the epoxy group of the epoxy compound (a). The carboxylic acid of (b) is preferably 0.01 to 0.5 mol, particularly preferably 0.1 to 0.3 mol. The reaction temperature may be 60-150 ° C. The reaction time is usually 5 to 30 hours. In this way, the reaction product (I) can be obtained.

  Next, the reaction of the reaction product (I) with the polybasic acid anhydride (c) is performed by adding 0.1% of the polybasic acid anhydride (c) per 1 equivalent of hydroxyl groups with respect to the hydroxyl groups in the reaction product (I). It is preferable to carry out 1-1.0 equivalent reaction. The reaction temperature is preferably 60 to 150 ° C., and the reaction time is usually 3 to 24 hours. Here, specific examples of the polybasic acid anhydride (c) include compounds represented by the following formulas, and two or more of these may be used.

  In the above reaction, as diluents, ketones such as ethyl methyl ketone, cyclohexanone and cyclopentanone, aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene, glycols such as dipropylene glycol dimethyl ether and dipropylene glycol diethyl ether Ethers, ethyl acetate, butyl acetate, butyl cellosolve acetate, esters such as carbitol acetate, aliphatic hydrocarbons such as octane and decane, petroleum ethers such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha It is preferable to use organic solvents. Furthermore, it is preferable to use a catalyst (for example, triphenylphosphine, benzyldimethylamine, methyltriethylammonium chloride, triphenylstibine, chromium octoate, etc.) to accelerate the reaction. Further, after the reaction is completed, the catalyst activity is substantially inactivated by oxidizing the used catalyst with an organic peroxide or the like. The amount of the catalyst used is preferably 0.1 to 10% by weight based on the reaction raw material mixture. In order to prevent polymerization during the reaction, it is preferable to use a polymerization inhibitor (for example, hydroquinone, methylhydroquinone, p-methoxyphenol, catechol, pyrogallol, etc.), and the amount used is based on the reaction raw material mixture. Preferably it is 0.01 to 1 weight%.

  The alkali-soluble epoxy compound (B) thus obtained is preferably an epoxy compound represented by the above formula (1). Such an alkali-soluble epoxy compound includes, as an epoxy compound (a), a cresol novolac type epoxy resin (commercially available products include EOCN-103, EOCN-104S, EOCN-4400H, manufactured by Nippon Kayaku Co., Ltd.). ) As a compound (b) having one or more carboxyl groups and one or more hydroxyl groups in one molecule, any of the anhydrides shown below as polybasic acid anhydrides (c) Can be obtained by reacting each of them according to the above.

  Furthermore, the alkali-soluble epoxy compound is particularly preferably an epoxy compound represented by the following formula (3).

In order to further improve the liquid storage stability, a phenol resin (C) may be added to the photosensitive resin composition of the present invention. As the phenol resin (C), a novolak resin obtained by addition condensation of an aromatic compound having a phenolic hydroxyl group and an aldehyde in the presence of an acid catalyst, a vinylphenol homopolymer (including a hydrogenated product), and vinyl. A vinylphenol polymer (including a hydrogenated product) selected from a copolymer of a component copolymerizable with phenol is preferably used. In the present invention, the phenol resin (C) may be used alone or in combination of two or more.
Specific examples of the aromatic compound having a phenolic hydroxyl group include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m- Butylphenol, p-butylphenol, o-xylenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3 , 4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, bisphenol A, terpene skeleton-containing diphenol, gallic acid, gallic acid ester, α-naphthol, β-naphthol and the like. . Similarly, aldehydes include formaldehyde, paraformaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, acetaldehyde and the like.

  Specific examples of the component copolymerizable with vinylphenol include acrylic acid or a derivative thereof, styrene or a derivative thereof, maleic anhydride, vinyl acetate, acrylonitrile and the like.

  The phenol resin (C) hardly participates in the crosslinking reaction during curing by photocationic polymerization. Accordingly, when a large amount of the phenol resin (C) is used (specifically, an amount exceeding 80% by weight), the degree of crosslinking is insufficient and patterning with an aspect ratio of 5 or more becomes difficult. Therefore, the blending ratio of the phenolic resin (C) is preferably 1 to 50% by weight, particularly preferably 5 to 25% by weight in the photosensitive resin composition of the present invention.

  The photosensitive resin composition of the present invention may be diluted with a solvent (D) for use. Examples of such a solvent (D) include ketones such as ethyl methyl ketone, cyclohexanone, cyclopentanone, and γ-butyrolactone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, dipropylene glycol dimethyl ether, Glycol ethers such as propylene glycol diethyl ether, ethyl acetate, butyl acetate, butyl cellosolve acetate, esters such as carbitol acetate, aliphatic hydrocarbons such as octane and decane, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, solvent naphtha And organic solvents such as petroleum solvents. These solvent (D) can be used individually or in mixture of 2 or more types.

  The solvent (D) is added for the purpose of adjusting the film thickness and applicability when applied to the substrate. In order to appropriately maintain the solubility of each component, the volatility of the solvent (D) itself, and the liquid viscosity of the photosensitive resin composition, 1 to 99 with respect to 100 parts by weight of the photosensitive resin composition of the present invention. Part by weight is preferred, with 10 to 90 parts by weight being particularly preferred.

  In this invention, a reactive monomer (E) can also be added to the photosensitive resin composition of this invention as needed. A polyfunctional glycidyl ether compound can be used as the reactive monomer (E). Specifically, for example, diethylene glycol diglycidyl ether, hexanediol diglycidyl ether, dimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether and the like can be used. These can be used alone or in admixture of two or more.

  Many of these reactive monomer components are liquid. When the component is in a liquid state, it is not preferable to add more than 20 parts by weight to the photosensitive resin composition because the film after the solvent is removed tends to be sticky and mask sticking is likely to occur. From this point, when the reactive monomer component is added, the addition ratio is preferably 10 parts by weight or less, particularly preferably 8 parts by weight or less with respect to 100 parts by weight of the photosensitive resin composition of the present invention. is there.

  In the present invention, a sensitizer may be used to absorb ultraviolet rays and to supply the absorbed light energy to the photocationic polymerization initiator. As the sensitizer, for example, an anthracene compound having an alkoxyl group at the 9-position and the 10-position (9,10-dialkoxy-anthracene derivative) is preferable. As an alkoxyl group, C1-C4 alkoxyl groups, such as a methoxyl group, an ethoxyl group, a propoxyl group, are mentioned, for example. The 9,10-dialkoxy-anthracene derivative may further have a substituent. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, C1-C4 alkyl group such as methyl group, ethyl group and propyl group, sulfonic acid alkyl ester group, and carboxylic acid alkyl ester group. Etc. Examples of the alkyl in the sulfonic acid alkyl ester group and the carboxylic acid alkyl ester include C1-C4 alkyl such as methyl, ethyl, and propyl. The substitution position of these substituents is preferably the 2-position.

  Specific examples of 9,10-dialkoxy-anthracene derivatives include 9,10-dibutoxy-anthracene, 9,10-dimethoxy-anthracene, 9,10-diethoxy-anthracene, 9,10-dipropoxy-anthracene, 9,10 -Dimethoxy-2-ethyl-anthracene, 9,10-diethoxy-2-ethyl-anthracene, 9,10-dipropoxy-2-ethyl-anthracene, 9,10-dimethoxy-2-chloro-anthracene, 9,10-dimethoxy Examples include anthracene-2-sulfonic acid methyl ester, 9,10-diethoxyanthracene-2-sulfonic acid methyl ester, and 9,10-dimethoxyanthracene-2-carboxylic acid methyl ester. These can be used alone or in admixture of two or more.

  The sensitizer component is effective in a small amount. Therefore, the use ratio is preferably 5 parts by weight or less, particularly preferably 2 parts by weight or less with respect to 100 parts by weight of the cationic photopolymerization initiator (B).

  In the present invention, an adhesion-imparting agent may be used for the purpose of improving the adhesion of the composition to the substrate. Examples of the adhesion-imparting agent include 3-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-methacryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl)- Examples include 3-aminopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane. These adhesiveness imparting agents can be used alone or in combination of two or more.

  The adhesion imparting agent does not show reactivity with the main component in the photosensitive resin composition of the present invention. Therefore, components other than those that act at the substrate interface will be present in the cured product as residual components after curing, and physical properties will decrease if used in large amounts (over 10 parts by weight relative to 100 parts by weight of the photosensitive resin composition). There are concerns about adverse effects. Depending on the substrate, it is appropriate to use it within a range that does not adversely affect it, since it can be effective even in a small amount (over 0.5 parts by weight or more with respect to 100 parts by weight of the photosensitive resin composition). The use ratio is preferably 10 parts by weight or less, particularly preferably 5 parts by weight or less, based on 100 parts by weight of the photosensitive resin composition of the present invention.

  In the present invention, when it is necessary to reduce the adverse effect of ions derived from the photocationic polymerization initiator, alkoxyaluminum such as trismethoxyaluminum, trisethoxyaluminum, trisisopropoxyaluminum, isopropoxydiethoxyaluminum, trisbutoxyaluminum, etc. Phenoxyaluminum such as trisphenoxyaluminum and trisparamethylphenoxyaluminum, trisacetoxyaluminum, tris stearate aluminum, trisbutyrate aluminum, trispropionato aluminum, trisacetylacetonatoaluminum, tristrifluoroacetylacetonatoaluminum Acetoaceto aluminum, diacetyl acetonato dipivaloyl methanato aluminum Diisopropoxy may be added (ethylacetoacetato) an organoaluminum compound, such as aluminum. These components can be used alone or in combination of two or more. Moreover, the addition amount is 10 weight part or less with respect to 100 weight part of photosensitive resin compositions of this invention.

  In the present invention, inorganic fillers such as barium sulfate, barium titanate, silicon oxide, amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, and mica powder are used. it can. The blending ratio is 0 to 60 parts by weight with respect to 100 parts by weight of the photosensitive resin composition of the present invention.

  Furthermore, in this invention, various additives, such as a thermoplastic resin, a coloring agent, a thickener, an antifoamer, a leveling agent, can be used as needed. Examples of the thermoplastic resin include polyethersulfone, polystyrene, and polycarbonate. Examples of the colorant include phthalocyanine blue, phthalocyanine green, iodin green, crystal violet, titanium oxide, carbon black, naphthalene black and the like. Examples of the thickener include olben, benton and montmorillonite. Examples of the antifoaming agent include silicone-based, fluorine-based and polymer-based antifoaming agents. When these additives are used, the amount used is about 0.5 to 30 parts by weight, for example, with respect to 100 parts by weight of the photosensitive resin composition of the present invention. It can be appropriately increased or decreased depending on

  The photosensitive resin composition of the present invention may be prepared by mixing and stirring the above components, and may be dispersed and mixed by using a disperser such as a dissolver, a homogenizer, or a three roll mill, if necessary. Moreover, after mixing, you may perform a filtration process using a mesh, a membrane filter, etc.

  Although the photosensitive resin composition of this invention is suitable as a resist composition for apply | coating as a thick film on a board | substrate, the utilization range is not limited to this. For example, it can also be used as a protective film during etching of various substrates such as copper, chromium, iron, and glass substrates, a resist mold during electrolytic plating, and a resist for semiconductor manufacturing.

Formation of the bumps using the photosensitive resin composition of the present invention as a thick resist film is performed, for example, as follows.
(1) Formation of coating film: A solution of the photosensitive resin composition prepared as described above is applied onto a predetermined substrate, and the solvent is removed by heating to form a desired coating film. As a coating method on the substrate to be processed, methods such as a spin coating method, a roll coating method, a screen printing method, and an applicator method can be employed. Although the prebaking conditions of the coating film of the photosensitive resin composition of the present invention vary depending on the type of each component in the composition, the blending ratio, the coating film thickness, and the like, it is usually 40 to 150 ° C, preferably 60 to 120 ° C. And about 2 to 60 minutes.

(2) Radiation irradiation: Exposing only the wiring pattern portion forming the bumps by irradiating the obtained coating film with radiation, for example, ultraviolet rays having a wavelength of 300 to 500 nm or visible rays through a mask having a predetermined pattern. Let As these radiation sources, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used. Here, the radiation means ultraviolet rays, visual rays, far ultraviolet rays, X-rays, electron beams, and the like. The amount of radiation irradiation varies depending on the type of each component in the composition, the blending amount, the film thickness of the coating film, and the like, but is, for example, 100 to 2000 mJ / cm ² when using an ultrahigh pressure mercury lamp.
(3) Heating: Heating is performed using a known method after exposure.

  (4) Development: As a development method after radiation irradiation, an alkaline aqueous solution is used as a developer to dissolve and remove unnecessary portions, leaving only the radiation irradiated portions. As a developing solution, alkaline aqueous solution, such as TMAH, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, can be used, for example. In addition, an aqueous solution obtained by adding a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution may be used as a developer. The development time varies depending on the type of each component of the composition, the blending ratio, and the dry film thickness of the composition. The developing method may be any of a liquid piling method, a dipping method, a paddle method, a spray developing method, and the like. After the development, washing with running water is performed for 30 to 180 seconds and dried using an air gun or an oven.

  The plating method is not particularly limited, and various plating methods known per se can be employed. As the plating solution, nickel plating, solder plating, or copper plating solution is particularly preferably used.

  The film thickness obtained with the photosensitive resin composition of this invention is 2-150 micrometers normally, Preferably it is 20-120 micrometers, More preferably, it is 40-90 micrometers.

  The photosensitive resin composition of the present invention is obtained by applying a coating solution obtained from a photosensitive resin composition on a base film using a roll coater, die coater, knife coater, bar coater, gravure coater, etc. A dry film resist can be obtained by drying in a drying furnace set to -100 ° C., removing a predetermined amount of solvent, and laminating a cover film or the like as necessary. At this time, the thickness of the resist on the base film is adjusted to 2 to 100 μm. As a base film and a cover film, for example, a film such as polyester, polypropylene, or polyethylene is used. To use this dry film resist, for example, the cover film is peeled off and transferred to a substrate, and exposure, development, and heating are performed in the same manner as described above. What is necessary is just to process.

  ADVANTAGE OF THE INVENTION According to this invention, the pattern formation of a high aspect ratio is possible by image development by aqueous alkali solution, and the highly sensitive photosensitive resin composition is provided. The photosensitive resin composition of the present invention is suitable for precision processing such as bump formation, metal post formation, and wiring formation.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Synthesis example of alkali-soluble epoxy compound Cresol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-4400H, epoxy equivalent 189) 1890 parts by weight (10 equivalents), dimethylolpropionic acid 301.8 parts by weight (2.25 Mol), 939.4 parts by weight of cyclopentanone, and heated to 80 ° C. and stirred to dissolve the mixture. Next, the obtained liquid was cooled to 60 ° C, charged with 8.0 parts by weight (0.03 mol) of triphenylphosphine, and heated to 100 ° C. The reaction was carried out for about 10 hours, and when the acid value (mgKOH / g) became 0.5 mgKOH / g or less, the mixture was cooled to 50 ° C. Next, 559.6 parts by weight (3.68 mol) of tetrahydrophthalic anhydride (manufactured by Shin Nippon Rika Co., Ltd.) and 559.6 parts by weight of cyclopentanone were charged and reacted at 95 ° C. for 10 hours. A cyclopentanone solution containing 70% by weight of the alkali-soluble epoxy compound (B-1) represented by the formula (3) where m = 0.9 and n = 2.1 was obtained. The acid value of the product (solid content) was 75 (mgKOH / g). The values of m and n are calculated as follows. Molecular weight of epoxy resin / molecular weight of repeating unit × charge amount of DMPA (mol) / equivalent number of epoxy resin = m, molecular weight of epoxy resin / molecular weight of repeating unit−m−1 = n. Here, the number of equivalents of epoxy resin = the amount of epoxy resin charged (parts by weight) / epoxy equivalent, the molecular weight was measured by GPC using the number average molecular weight, and the epoxy equivalent was measured by the method described in JIS K-7236. .

Examples 1-3, Comparative Example 1
(Photosensitive resin composition)
According to the blending amount shown in Table 1 (unit is part by weight), the alkali-soluble epoxy resin, the photocationic polymerization initiator, and other components were stirred in a flask equipped with a stirrer at 60 ° C. for 1 hour to prepare a photosensitive composition. Obtained.

(Patterning of photosensitive resin composition)
This photosensitive resin composition was applied onto a silicon wafer with a spin coater and then dried to obtain a photosensitive resin composition layer having a thickness of 80 μm. This photosensitive resin composition layer was prebaked on a hot plate at 65 ° C. for 5 minutes and at 95 ° C. for 20 minutes. Thereafter, pattern exposure (soft contact, i-line) is performed using an i-line exposure apparatus (mask aligner: manufactured by USHIO INC.), And post-exposure baking (PEB) is performed at 95 ° C. for 6 minutes using a hot plate. Development processing was performed at 23 ° C. for 7 minutes by an immersion method using a 38% TMAH aqueous solution to obtain a resin pattern cured on the substrate.

(Evaluation of photosensitive resin composition)
After the development, the following evaluation was performed according to the required exposure amount. The results are shown in Table 1 below.

Optimum exposure amount: Exposure amount with the best mask transfer accuracy Aspect ratio: Film thickness / The finest pattern width closely adhered in the formed resist pattern

note:
(A-1): Photocationic polymerization initiator (trade name: CPI-210S manufactured by San Apro)
(B-1): Alkali-soluble epoxy compound synthesized according to synthesis example (C): Hydrogenated product of polyvinylphenol (trade name Marcalinker PHM-C, manufactured by Maruzen Petrochemical Co., Ltd.)
(D): Solvent Cyclopentanone (E): Fluorine-based leveling agent (trade name: Megafac F-470, manufactured by Dainippon Ink, Inc.)
(F): Silane coupling agent (trade name: S-510, manufactured by Chisso Corporation)
(G): Photocationic polymerization initiator (trade name: UVI-6974, 50% propylene carbonate solution manufactured by Dow Chemical Company)

  As shown in Table 1, Examples 1 to 3 were all good results.

Example 4
(Photosensitive resin composition)
Photosensitivity obtained by mixing 100 parts by weight of the alkali-soluble epoxy compound (B-1) synthesized according to the synthesis example, 4.6 parts by weight of a photocationic polymerization initiator (trade name: CPI-210S manufactured by San Apro), and 40 parts by weight of MEK. Sex composition was obtained.
(Patterning of photosensitive resin composition)
This photosensitive resin composition was uniformly applied onto a polypropylene (PP) film (base film, manufactured by Toray Industries, Inc.) having a film thickness of 60 μm, and dried at 65 ° C. for 10 minutes and at 80 ° C. for 15 minutes by a hot air convection dryer. Thereafter, a PP film (cover film) having a film thickness of 60 μm was laminated on the exposed surface to form a photosensitive resin composition laminate having a film thickness of 40 μm.

The cover film of this photosensitive resin composition laminate is peeled off and laminated on a silicon wafer at a roll temperature of 70 ° C., an air pressure of 0.2 MPa, and a speed of 0.5 m / min. A composition layer was obtained. This photosensitive resin composition layer was subjected to pattern exposure (soft contact, i-line) using an i-line exposure apparatus (mask aligner: manufactured by Ushio Inc.). Thereafter, PEB was carried out at 95 ° C. for 6 minutes by a hot plate, and development processing was carried out at 23 ° C. for 7 minutes by a dipping method using a 2.38% TMAH aqueous solution to obtain a cured resin pattern on the substrate. Good results were obtained with an optimum exposure of 350 mJ / cm ² and an aspect ratio of 5.3.

  From the comparison of the evaluation results of Examples 1 to 4 and Comparative Example 1, the combination of a specific alkali-soluble epoxy resin and a specific photocationic polymerization initiator has a high-sensitivity and high-aspect profile that cannot be obtained by other combinations. It was found that a resin pattern was obtained.

  As described above, the photosensitive resin composition according to the present invention is useful for forming a resin pattern having a high aspect profile, and is particularly suitable for resin molding with high dimensional stability in a fine size electronic device. Yes. More specifically, this photosensitive resin composition is used for bump formation, metal post, which is performed in the manufacture of MEMS parts, micromachine parts, μ-TAS (micro total analysis system) parts, microreactor parts, electronic parts, etc. It is suitably used for precision processing such as formation and wiring formation.

Claims (9)

  Photocationic polymerization initiator (A) which is sulfonium tris (pentafluoroethyl) trifluorophosphate, epoxy compound (a) having two or more epoxy groups in one molecule, and one or more carboxyl groups in one molecule And an alkali-soluble epoxy compound (B) obtained by reacting a polybasic acid anhydride (c) with a reaction product (I) of a compound (b) having one or more hydroxyl groups. object. The photosensitive resin composition according to claim 1, wherein the alkali-soluble epoxy compound (B) is represented by the following general formula (1).

(In Formula (1), m and n are average values, each independently represents a real number of 0 or more, and the sum is a real number of 0 to 30. Also, D ₁ and D ₂ are the same. Or may be different and represents any group selected from the group consisting of the groups shown below.)

The photosensitive resin composition according to claim 1 or 2, wherein the cationic photopolymerization initiator (A) is a compound (A-1) represented by the following formula (2).

  The photosensitive resin composition as described in any one of Claims 1-3 containing a phenol resin (C).   The photosensitive resin composition as described in any one of Claims 1-4 whose solid content concentration is 5 to 95 weight% in the photosensitive resin composition containing a solvent (D).   The photosensitive resin composition laminated body which pinched | interposed the photosensitive resin composition as described in any one of Claims 1-5 with the base material.   Hardened | cured material which comprises the photosensitive resin composition as described in any one of Claims 1-5.   The photosensitive resin composition layer obtained by applying the photosensitive resin composition according to any one of claims 1 to 5 on a desired support is dried and then exposed to a predetermined pattern. Baking after exposure, developing a resin composition layer, and heat-treating the obtained resin pattern to obtain a cured resin pattern having a predetermined shape.   The photosensitive resin composition layer remaining after removing the base material from the laminate according to claim 6 is laminated on a desired support, and the photosensitive resin composition layer is exposed to a predetermined pattern, and exposed. A pattern forming method comprising post-baking, developing the resin composition, and heat-treating the obtained resin pattern to obtain a cured resin pattern having a predetermined shape.