JP2002229204A - Photosensitive resin composition - Google Patents

Abstract

(57) [Problem] To provide a novel negative photosensitive resin composition capable of supplying a high-sensitivity, high-resolution resist pattern that can be developed with a dilute alkaline solution. A photosensitive resin composition containing at least an alkali-soluble resin, a crosslinking agent, and a photopolymerization initiator, wherein the alkali-soluble resin comprises an organic polymer having a phenolic hydroxyl group, and an oxirane compound and / or an oxetane compound A photosensitive resin composition characterized in that it is a polymer containing a compound modified by the above as a structural unit. Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for removing unexposed portions easily with a dilute alkaline solution during photocuring,
The exposed portion relates to a photosensitive resin composition that becomes insoluble, and relates to a novel negative photosensitive resin composition capable of supplying a resist pattern with high sensitivity and high resolution. Widely used in the electronics industry.

[0002]

2. Description of the Related Art With the development of metal processing industry, electronics industry, printing, paint and ink industry, etc., photosensitive resin has been widely used in various fields. The main specific applications are (a) production of copper-clad laminates by partial metal etching, production of precision electronic circuits such as LSI, (b) production of printing resin plates, and (c) screen printing. Such as ink. Therefore, the final purpose of use, conditions,
Modification of the photosensitive resin is naturally required from the viewpoint of simplification of the process on the creator side and environmental considerations. At present, various types of photosensitive resins having different characteristics are commercially available and marketed.

The photosensitive resin has two types, a positive resist in which an exposed portion is removed during a developing process to obtain a positive pattern, and a negative resist in which an unexposed portion is removed and a negative pattern is obtained. is there. In general, a negative type has better sensitivity, adhesion to a substrate, and chemical resistance than a positive type, and a positive type has better resolution and dry etching resistance than a negative type.

The following steps are used when fabricating a circuit by partially etching a metal foil or the like using this negative photosensitive resin, or fabricating a resin plate for printing. A negative mask is placed on the thin film of the applied photosensitive resin composition, the exposed portion is cured by irradiating light through the negative mask, and the non-exposed portion is removed by washing. It is eluted by immersion to produce a circuit. Further, in the plate making for printing, an etching step is unnecessary.

A conventional photosensitive resin composition is obtained by polymerizing a (meth) acrylic polymerizable monomer or the like.
A polymer compound having an unsaturated double bond in the molecular structure,
Some include a photopolymerization initiator and a photocrosslinking agent. As a characteristic of such a photosensitive resin composition, development is often performed using an organic solvent, which is not preferable in terms of environmental protection, and its use is problematic.

[0006] Further, with the miniaturization of products, a large number of components having a fine structure are used in many products. In order to construct such a fine structure and to improve the throughput in mass production, the photosensitive resin composition is used. Improvements in sensitivity and resolution are both important factors. Furthermore, it is desirable that the photosensitive resin composition has good storage stability.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive resin composition which can be developed using an alkaline aqueous solution, has high sensitivity and high resolution, and has good storage stability. It is in.

[0008]

The photosensitive resin composition according to the present invention comprises an alkali-soluble resin, a cross-linking agent and a photopolymerization initiator, and has a phenolic hydroxyl group as the alkali-soluble resin. By using a polymer having a structural unit of a compound obtained by modifying an organic polymer having an oxirane compound and / or an oxetane compound, unexposed portions can be removed with an alkaline solution during development, and high sensitivity and high resolution can be achieved. In addition, the storage stability is good.

That is, the invention according to claim 1 is a photosensitive resin composition containing at least an alkali-soluble resin, a crosslinking agent and a photopolymerization initiator, wherein the alkali-soluble resin has a phenolic hydroxyl group. Is a polymer containing, as a structural unit, a compound represented by the following general formula (1), which is modified with an oxirane compound and / or an oxetane compound.

[0010]

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The invention according to claim 2 is a photosensitive resin composition containing at least an alkali-soluble resin, a crosslinking agent, and a photopolymerization initiator, wherein the alkali-soluble resin contains an oxirane ring and / or an oxetane ring. Modified poly (p-hydroxystyrene) represented by the following general formula (2)
It is a photosensitive resin composition characterized by these.

[0012]

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The invention according to claim 3 is the photosensitive resin according to claim 1 or 2, wherein the modification ratio of the alkali-soluble resin with an oxirane and / or oxetane compound is in the range of 1 to 50%. A composition.

According to a fourth aspect of the present invention, the alkali-soluble resin has a weight average molecular weight of 1,000 or more and 100,0 or more.
The photosensitive resin composition according to any one of claims 1 to 3, wherein the composition is not more than 00.

According to a fifth aspect of the present invention, there is provided the photosensitive resin composition according to any one of the first to fourth aspects, wherein the crosslinking agent has cationic polymerizability.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The advantages of using an organic polymer or a poly (p-hydroxystyrene) having a phenolic hydroxyl group as the alkali-soluble resin are that it is rapidly dissolved in an alkali solution and has excellent developability. It is excellent in compatibility, and can be obtained relatively inexpensively. Further, the position of the hydroxyl group of the organic polymer having a phenolic hydroxyl group is not limited, but it is preferred that the organic polymer having the phenolic hydroxyl group is at the P-position because the stability is increased. Further, by using the above-mentioned organic polymer having a phenolic hydroxyl group or one obtained by introducing an oxirane ring and / or an oxetane ring into poly (p-hydroxystyrene), a photosensitive resin composition having high sensitivity and high resolution can be obtained. Can be In the present invention, the term "modification" refers to the substitution of a part of the hydroxyl group on the side chain of the organic polymer having a phenolic hydroxyl group or poly (p-hydroxystyrene) with a structural unit containing another functional group. is there.

The alkali-soluble resin in the photosensitive resin composition of the present invention can be represented by a structural unit having an oxirane ring and / or an oxetane ring and represented by the following general formula (1) or (2). ) It may be a polymer containing, as a structural unit, a polymer obtained by partially modifying an organic polymer having a phenolic hydroxyl group, or may be composed of only (b) modified poly (p-hydroxystyrene). In the former case (a), a copolymerizable compound can be polymerized,
There are no particular restrictions on the type of such compounds, and any number of compounds can be used as needed. For example, styrene-based monomers such as styrene, α-methylstyrene, parahydroxyl styrene, etc .; , Vinyl ether acids such as ethyl vinyl ether, maleic anhydride, vinyl acetate,
Vinyl pyridine and the like. Although the method of the modification is not particularly limited, for example, the poly (p
-Hydroxystyrene) can be easily obtained by reacting a halogen-containing oxirane and / or oxetane compound such as epichlorohydrin and then a base such as NaOH.

[0019]

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[0020]

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The functional groups containing an oxirane ring and / or an oxetane ring represented by X in the above general formulas (1) and (2) can be represented by the following general formulas (3) to (6). It is not limited to these. Further, the oxirane and / or oxetane compound used is made of two or more kinds, and the oxirane ring and / or
More than one kind may be contained.

[0022]

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The degree of modification of the polymer or modified poly (p-hydroxystyrene) containing a partially modified organic polymer having a phenolic hydroxyl group by an oxirane and / or oxetane compound is 1 to 3. 50
%, The effect of denaturation is not exhibited when the amount is less than this, a high-sensitivity, high-resolution resist is not obtained, and when the amount is more than this, the alkali solubility of the photosensitive resin composition is increased. Is undesirably reduced.

The molecular weight of the polymer or modified poly (p-hydroxystyrene) containing as a structural unit a partially modified organic polymer having a phenolic hydroxyl group has a weight average molecular weight of 1,000 or more; If it is less than 2,000, the strength of the cured film is remarkably reduced, and if it is more than this, the solubility is reduced, and the preparation of the resist becomes difficult. Considering sensitivity and resolution, the weight average molecular weight is 1,000.
More preferably, it is in the range of 20,000 or less.

In the photosensitive resin composition of the present invention, the cross-linking agent is a compound having cationic polymerizability, and any compound capable of polymerizing or cross-linking by light in the presence of an initiator generating cations by light. Often, it comprises one or a mixture of two or more of an epoxy compound, a cyclic ether compound, a cyclic lactone compound, a cyclic acetal compound, a cyclic thioether compound, a spiroorthoester compound, a vinyl ether compound and the like. Among the compounds having such a cationically polymerizable compound, those having at least one epoxy group in one molecule and having high solubility, particularly high solubility in water, are preferable. For example, aliphatic polyol glycidyl ether compounds And alicyclic epoxy compounds.

Examples of the aliphatic polyol glycidyl ether include aliphatic polyhydroxy compounds such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, tripropylene glycol, neopentyl glycol, 1,3-propane Diols, mono-, di-, such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol;
Alternatively, polyglycidyl ethers may be mentioned, but not limited thereto.

Examples of the alicyclic epoxy compound include hydrogenated glycidyl ethers, particularly hydrogenated bisphenol A, hydrogenated bisphenol A produced by reacting bisphenol A or its alkylene oxide adduct with epichlorohydrin. Bisphenol AD, hydrogenated bisphenol B, hydrogenated bisphenol AF, hydrogenated bisphenol S,
Examples include hydrogenated brominated bisphenol A, but not limited thereto.

The photopolymerization initiator in the present invention may be any compound that generates a cationic species upon external stimulation by light such as ultraviolet rays. Photo
ochem. Sci. Technol. , 2,283
(1987). Compounds, specifically iron arene complex, trihanogenomethyl-substituted s-triazine, sulfonium salt, diazonium salt, phosphonium salt,
Selenonium salts, arsonium salts, iodonium salts,
Examples include, but are not limited to, tetrafluoroborate salts, hexafluorophosphate salts, hexafluoroarsenate salts, and tetrafluoroantimonate salts of benzyltriarylphosphoniums.

The amount of the crosslinking agent contained in the photosensitive resin composition of the present invention can be in the range of 20 to 100 parts by weight, preferably 30 to 100 parts by weight of the alkali-soluble resin. To 60 parts by weight. Further, the amount of the photopolymerization initiator can be in the range of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the alkali-soluble resin.

In the photosensitive resin composition of the present invention, in addition to the above-mentioned components, if necessary, compatible additives such as a polymerization inhibitor, a plasticizer, a stabilizer, a surfactant, a coloring agent, a leveling agent, Coupling agents and the like can be added as long as the object of the present invention is not impaired.

As described above, the photosensitive solution obtained by appropriately selecting each component and mixing at an arbitrary ratio is used in a known manner such as a bar coater, an applicator, a doctor blade, a roll coater, a spin coater, a roll coater, a die coater, and a comma coater. Is applied on a substrate such as a plastic film typified by stainless steel, glass, or polyester by using the above coating means.

When the photosensitive solution is prepared, it may be diluted with an appropriate solvent if necessary, but in that case, it is necessary to apply the solvent on a substrate and then dry it. As the solvent,
Dichloromethane, chloroform, acetone, 2-butanone, cyclohexanone, ethyl acetate, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-ethylethoxy acetate, 2-butoxyethyl acetate, 2-methoxyethyl ether,
2-ethoxyethyl ether, 2- (2-ethoxyethoxy) ethanol, 2- (2-butoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethyl acetate, 2- (2-butoxyethoxy) ethyl acetate,
Examples include tetrahydrofuran and 1,4-dioxane.

On the photosensitive layer formed by the above method,
After adhering a photomask having a predetermined pattern, for example, by exposure with an ultra-high pressure mercury lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, a halogen lamp, etc., and polymerizing or crosslinking the light-irradiated portion, an alkali developer , An image faithful to the mask pattern can be obtained. If necessary, heat treatment can be performed to harden the film.

Hereinafter, embodiments of the present invention will be described in which only modified poly (p-hydroxystyrene) is used as an example, but the present invention is not limited to the examples described below. Further, since the photosensitive resin composition of the present invention is extremely sensitive to light, it goes without saying that all operations are performed under yellow or red light to prevent exposure to unnecessary light such as natural light.

[0035]

EXAMPLES <Synthesis Example 1> Synthesis of partial 2-glycidyl ether (modification ratio: 20%) of poly (p-hydroxystyrene) Poly (p-hydroxystyrene) (Mw = 5,000,
Mn = 2,300, OH value = 120, 10 g of Maruzen Petrochemical Co., Ltd.) and 1.6 g of epichlorohydrin were added to 60 ml of ethyl acetate, stirred for 1 hour, 0.75 g of sodium hydroxide was added, and 60 ° C. Stir for 6 hours. The precipitate was reprecipitated with toluene, and the obtained precipitate was dried in vacuo to obtain 9.1 g of a partially 2-glycidyl ether of poly (p-hydroxystyrene) having a modification rate of 20%.

<Synthesis Example 2> Partial 3-ethyl-3 of poly (p-hydroxystyrene)
-Methyloxetane-4'-ether (denaturation rate 20%)
Synthesis of 3-ethyl-3-hydroxymethyloxetane (EOX
A, manufactured by Toa Gosei Co., Ltd.)
4.2 g, stirred in toluene, after the reaction was completed, the reaction product was taken out, purified using silica gel chromatography, and 8.4 g of 3-chloromethyl-3-ethyloxetane.
I got

The same operation as in Synthesis Example 1 was carried out except that 1.6 g of epichlorohydrin was replaced by 2.5 g of 3-chloromethyl-3-methyloxetane synthesized as described above.
10.1 g of a partially 3-ethyl-3-methyloxetane-4′-ether of poly (p-hydroxystyrene) having a modification rate of 20% was obtained.

Example 1 10 g of the modified poly (p-hydroxystyrene) obtained in Synthesis Example 1, 8.0 g of glycerol polyglycidyl ether (Denacol EX-313, manufactured by Nagase Kasei Kogyo Co., Ltd.) Screw (p-ter
A photosensitive solution was prepared by mixing and dissolving 0.2 g of (t-butylphenyl) iodonium in 10 g of 2-butanone. The photosensitive solution was degreased, washed with water, and dried to form a blue plate glass (1.1 mm).
Thickness, 5 inch square), applied with a doctor blade so that the film thickness becomes 20 μm, dried at 80 ° C. for 10 minutes,
A photosensitive layer was formed, and a 50 μm polyester film was stuck on the surface.

An ultra-high pressure mercury lamp (HMW-532,
500mJ / cm ^-2 using Oak Manufacturing Co., Ltd.)
Immediately after the exposure, the aqueous solution of tetramethylammonium hydroxide (MF-312, manufactured by Shipley Co., Ltd. with deionized water)
When developed with KodakPh
autographic Step Tablet N
o. 2 (hereinafter referred to as gray scale) sensitivity was 7 and resolution was 40 μm. This sensitivity did not change when developed after standing for 24 hours after exposure.

Example 2 Glycerol polyglycidyl ether was converted to trimethylolpropane polyglycidyl ether (Denacol EX-321, Nagase Kasei Kogyo Co., Ltd.)
The same operation as in Example 1 was carried out, except that the above procedure was replaced with the same. The gray scale sensitivity was 7 and the resolution was 40 μm. This sensitivity did not change when developed after standing for 24 hours after exposure.

Example 3 An operation was performed in the same manner as in Example 1 except that glycerol polyglycidyl ether was replaced with hydrogenated bisphenol A diglycidyl ether (Denacol EX-252, manufactured by Nagase Kasei Kogyo Co., Ltd.). When. The gray scale sensitivity was 7 and the resolution was 40 μm. This sensitivity did not change when developed after standing for 24 hours after exposure.

Example 4 Glycerol polyglycidyl ether was converted to 4 ', 5'-epoxy-2'-methylcyclohexyl-4,5-epoxy (Araldite CY17
Example 1 except that the first embodiment was replaced with No. 9, manufactured by Asahi Chiba Corporation.
The operation was performed in the same manner as described above. The gray scale sensitivity was 8, and the resolution was 30 μm. This sensitivity did not change when developed after standing for 24 hours after exposure.

Example 5 An operation was performed in the same manner as in Example 1 except that the resin synthesized in Synthesis Example 1 was changed to the resin synthesized in Synthesis Example 2. Gray scale sensitivity is 7
And the resolution was 40 μm. This sensitivity is 24 hours after exposure.
The case where development was carried out after standing for the same time did not change.

Example 6 An operation was performed in the same manner as in Example 2 except that the resin synthesized in Synthesis Example 1 was changed to the resin synthesized in Synthesis Example 2. Gray scale sensitivity is 7
And the resolution was 40 μm. This sensitivity is 24 hours after exposure.
The case where development was carried out after standing for a long time did not change.

Example 7 An operation was performed in the same manner as in Example 3 except that the resin synthesized in Synthesis Example 1 was changed to the resin synthesized in Synthesis Example 2. Gray scale sensitivity is 7
And the resolution was 40 μm. This sensitivity is 24 hours after exposure.
The case where development was carried out after standing for a long time did not change.

Example 8 An operation was performed in the same manner as in Example 4 except that the resin synthesized in Synthesis Example 1 was changed to the resin synthesized in Synthesis Example 2. Gray scale sensitivity is 8
And the resolution was 30 μm. This sensitivity is 24 hours after exposure.
The case where development was carried out after standing for a long time did not change.

Example 9 Resin 1 synthesized in Synthesis Example 1
The same operation as in Example 1 was performed, except that 0 g was changed to 5 g each of the resins synthesized in Synthesis Examples 1 and 2. Gray scale sensitivity is 7 and resolution is 40 μm
Met. This sensitivity did not change when developed after standing for 24 hours after exposure.

Comparative Example 1 Partial 2-glycidyl ether of poly (p-hydroxystyrene) (etherification rate 20
%) Was replaced with poly (p-hydroxystyrene). The gray scale sensitivity was 5 and the resolution was 50 μm. In addition, cracks occurred in the obtained cured film.

[0049]

As described above, according to the present invention, the gray scale sensitivity is as high as 7 to 8 as compared with 5 in the comparative example and 40 μm or more as compared with the resolution of 50 μm in the comparative example under the same light amount. It is possible to provide a photosensitive resin composition which has a high resolution and a good storage stability without causing cracks in the cured film observed in Comparative Examples.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/038 503 G03F 7/038 503 H01L 21/027 H01L 21/30 502R (72) Inventor Midori Ohara Tokyo 1-5-1, Taito, Tokyo Taito-ku, Toppan Printing Co., Ltd. (72) Inventor Yasushi Oe 1-15-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. F-term (reference) 2H025 AA01 AA02 AA09 AA11 AA14 AB01 AB15 AB16 AC01 AD01 BC83 BC92 BD22 CA00 CA43 CB41 CB52 CB56 CC17 FA17 4J002 BC12W CD01X CD02X CD04X EB006 EU186 EV296 EW176 EY016 EY026 EZ006 FD14X FD206 GP03

Claims (5)

[Claims] 1. A photosensitive resin composition comprising at least an alkali-soluble resin, a cross-linking agent and a photopolymerization initiator, wherein the alkali-soluble resin comprises an oxirane compound and / or an oxetane. A photosensitive resin composition characterized by being a polymer modified by a compound and containing a compound represented by the following general formula (1) as a structural unit. Embedded image 2. A photosensitive resin composition comprising at least an alkali-soluble resin, a crosslinking agent and a photopolymerization initiator, wherein said alkali-soluble resin contains an oxirane ring and / or an oxetane ring. A photosensitive resin composition characterized by being a modified poly (p-hydroxystyrene) represented by the following formula: Embedded image 3. The photosensitive resin composition according to claim 1, wherein the modification ratio of the alkali-soluble resin with an oxirane and / or oxetane compound is in the range of 1 to 50%. 4. The photosensitive resin composition according to claim 1, wherein the alkali-soluble resin has a weight average molecular weight of 1,000 or more and 100,000 or less. 5. The photosensitive resin composition according to claim 1, wherein said crosslinking agent has cationic polymerizability.