JP2003114531A - Chemically amplified negative photoresist composition for thick film, photoresist base material and method of forming bump using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemically amplified negative photoresist composition for thick films having high sensitivity and good plating resistance and suitable for the formation of thick films favorable for use as materials for forming bumps, re-wiring and a metal post used in a CSP manufacturing technique and to provide a photoresist base material and a method for forming bumps using the same. SOLUTION: In the chemically amplified negative photoresist composition for thin films having 20-150 μm thickness including (A) an alkali-soluble resin, (B) a compound which generates an acid upon irradiation with a radiant ray and (C) a compound which takes part in a crosslinking reaction in the presence of an acid, the component (A) comprises a mixture of (a1) a novolak resin having a weight average molecular weight of 5,000-10,000 and (a2) a copolymer containing at least a hydroxystyrene constitutional unit and having a weight average molecular weight of <=5,000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemically amplified negative photoresist composition for thick film, a photoresist base material and a bump forming method using the same. More specifically, the present invention relates to bump formation, wiring formation, metal post formation, and interlayer insulation performed when manufacturing a circuit board and mounting a semiconductor or an electronic component represented by CSP (chip size package) on the circuit board. The present invention relates to a chemically amplified negative-working photoresist composition for a thick film, which is suitable for photofabrication such as a layer, a circuit protective film, and precision component processing / manufacturing.

[0002]

2. Description of the Related Art Photofabrication is mainly applied to chemical etching, electrolytic etching or electroplating by applying a photosensitive resin composition to the surface of a work and patterning the coating by photolithography. It is a general term for the technology of manufacturing various precision parts by using electroforming technology alone or in combination, and it is the mainstream of the current precision micromachining technology. In recent years, with the downsizing of electronic devices, high-density mounting technology of LSI has advanced, and multi-pin thin-film mounting of LSI, package size reduction, two-dimensional mounting technology by flip chip method, and mounting based on three-dimensional mounting technology The density is being improved. In such high-density mounting technology, bump electrodes, which are called connection terminals, having a height of 20 μm or more, rewiring from the peripheral terminals on the wafer to the mounting terminal positions, ultra-thick film wiring called metal posts, etc. Must be placed on the board with high precision,
In the future, the demand for high-density packaging technology will become even stronger in response to further miniaturization of LSI. A thick film photoresist is used as a material used in such package manufacturing and IC bumping process. The thick film here means a film thickness of 20 to 150 μm. Such a thick film is used, for example, as a mask for forming bumps and metal posts by a plating process, forming a lead frame by a metal etching process, and dry etching by using the thick film pattern as a mask.

For example, Japanese Patent Laid-Open No. 10-207057,
JP-A-2000-39709, JP-A-2000-66
Japanese Patent No. 386 describes a thick film photosensitive resin composition used for forming a pump or forming a wiring. However, since these conventional thick film photosensitive resin compositions are thick films, many reaction initiators are required to sufficiently react the entire resist film. However, when there are many reaction initiators, the compatibility tends to deteriorate and the storage stability tends to decrease. Therefore, a reaction initiator having higher sensitivity has been demanded.

On the other hand, as a highly sensitive photosensitive resin composition,
A chemically amplified resist using an acid generator is known.
A feature of the chemically amplified resist is that a protonic acid generated from an acid generator as a component by irradiation with radiation causes an acid-catalyzed reaction with a base resin or the like in a resin composition by a heat treatment after exposure. In this way, the photosensitivity (reaction per one photon) is dramatically higher than that of the conventional resist having a photoreaction efficiency of less than 1. Typical examples of the chemically amplified negative resist include SPIE proceeding (SPIE) proceeding.
86, 34-47 (1989). E. Bog
A resist is described which combines a polyvinylphenol and a melamine derivative of an et al. However, when a thick film was formed using these chemically amplified resists, cracks (cracks) occurred and the required plating resistance could not be obtained. Further, in the case of exposing a conventional thick film photoresist, contact exposure in which an exposed portion comes into contact with the resist has been preferably used because of problems such as light diffusion during exposure. However, proximity exposure (gap exposure) in which there is a gap between the exposed portion and the resist portion is more advantageous in the manufacturing process, and there has been a demand for a thick film resist having sufficient performance even with the exposure method.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to provide high sensitivity, good plating resistance, and materials for forming bumps, rewirings, metal posts, Another object is to provide a thick film chemically amplified negative photoresist composition suitable for forming a thick film suitable as a material for CSP, a photoresist base material, and a bump forming method using the same.

[0006]

According to the invention of claim 1,
A chemically amplified negative photoresist composition containing (A) an alkali-soluble resin, (B) a compound that generates an acid upon irradiation with radiation, and (C) a compound that undergoes a crosslinking reaction in the presence of an acid. The component is composed of a mixture of (a) a novolac resin having a weight average molecular weight of 5,000 to 10,000 and (b) a polymer having at least a hydroxystyrene structural unit and having a weight average molecular weight of 5,000 or less. A chemically amplified negative photoresist composition for a film. The invention of claim 2 is characterized in that the component (a) is composed of m-cresol novolac resin obtained by condensing m-cresol and aldehydes in the presence of an acid catalyst. It is a chemically amplified negative photoresist composition for thick film. According to the invention of claim 3, in the component (A), when the total amount of the component (a) and the component (b) is 100 parts by weight, the amount of the component (a) is 50 to 98.
The chemical amplification type negative photoresist composition for thick film according to claim 1, wherein the amount of the component (b) is 50 to 2 parts by weight. A fourth aspect of the present invention, (B) component, the general formula _{R-SO 2 O-N =} C (CN) - is represented by (wherein, R is a substituted or unsubstituted alkyl group or an aryl group) The chemically amplified negative photoresist composition for thick film according to claim 1, which is a compound having at least two oxime sulfonate groups. The invention of claim 5, (B) component, the general formula _{R-SO 2 O-N =} C (CN) -A-C (CN) = N-
The chemical amplification for thick film according to claim 4, which is a compound represented by OSO ₂ -R (wherein A is a divalent organic group, and R is a substituted or unsubstituted alkyl group or aryl group). Negative photoresist composition. The invention of claim 6 is the chemical amplification type negative photoresist composition for thick film according to claim 5, wherein A in the general formula of the component (B) is a phenylene group and R is a lower alkyl group. The invention of claim 7 is characterized in that the component (B) is 0.1 to 1 part by weight, when the total of the components (A), (B) and (C) is 100 parts by weight. The chemically amplified negative photoresist composition for thick film according to claim 1. The invention of claim 8 is a negative photoresist base material having a substrate and a negative photoresist layer provided thereon, wherein the negative photoresist layer is the thickness of any one of claims 1 to 7. A photoresist base material comprising a chemically amplified negative photoresist composition for a film and having a film thickness of 20 to 150 μm. The invention of claim 9 applies the chemical amplification type negative photoresist composition for thick film according to any one of claims 1 to 7 onto a substrate of an electronic component, and selects the resulting coating film. The bump forming method is characterized in that after the negative exposure resist pattern is formed by sequentially performing the selective exposure, the heat treatment, and the development process, the plating process is performed using the resist pattern as a mask.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of earnest research, the present inventors have clarified that the characteristics required of a resist vary depending on the type of plating solution, and have solved the above problems by optimizing its constituent elements. In particular, they have found a chemically amplified negative photoresist composition for thick film, which is more preferably used in the steps of solder plating and copper plating.

The composition of the present invention will be described below. The component (A) of the alkali-soluble resin (A) has a weight average molecular weight of 5,000 to 10 (a).
It is an alkali-soluble resin composed of a mixture of a novolak resin in the range of 000 and (b) a polymer having at least a hydroxystyrene structural unit and having a weight average molecular weight of 5000 or less.

(A) Novolac resin The (a) novolak resin used in the present invention is, for example, addition-condensation of an aromatic compound having a phenolic hydroxyl group (hereinafter, simply referred to as "phenol") and an aldehyde with an acid catalyst. Can be obtained. Examples of the phenols used at this time include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p.
-Butylphenol, 2,3-xylenol, 2,4-
Xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-
Trimethylphenol, p-phenylphenol, resorcinol, fodroquinone, hydroquinone monomethyl ether, pyrogallol, phloroglicinol, hydroxydiphenyl, bisphenol A, gallic acid, gallic acid ester, α-naphthol, β-naphthol and the like can be mentioned. Examples of aldehydes include formaldehyde, paraformaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, acetaldehyde and the like. The catalyst for the addition condensation reaction is not particularly limited, but examples of acid catalysts that can be used include hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid and acetic acid. (A) The weight average molecular weight of the alkali-soluble novolac resin is preferably 5,000 to 10,000. Further, the m-cresol novolak resin obtained by condensing m-cresol and aldehydes is particularly suitable for a chemically amplified negative photoresist composition for thick film.

(B) Polymer Having Hydroxystyrene Constituent Unit The component (b) used in the present invention includes a polymer having at least a hydroxystyrene constituent unit. For example, the polymer is a radical or ionic polymer of hydroxystyrene such as p-hydroxystyrene, α-methylhydroxystyrene, α-alkylhydroxystyrene monomer such as α-ethylhydroxystyrene,
Examples of the copolymer include hydroxystyrene structural units such as hydroxystyrene and α-alkylhydroxystyrene, and structural units other than the hydroxystyrene structural units. Preferred examples of the monomer that forms a structural unit other than the hydroxystyrene structural unit include a monomer in which the hydroxyl group of hydroxystyrene is substituted with another group, or a monomer having an α, β-unsaturated double bond. . As the other group that replaces the hydroxyl group of the hydroxystyrene, an alkali dissolution inhibiting group that does not dissociate with acid is used. Examples of the alkali dissolution suppressing group include a substituted or unsubstituted benzenesulfonyloxy group, a substituted or unsubstituted naphthalenesulfonyloxy group, a substituted or unsubstituted benzenecarbonyloxy group, and a substituted or unsubstituted naphthalenecarbonyloxy group. Specific examples of the substituted or unsubstituted benzenesulfonyloxy group include a benzenesulfonyloxy group, a chlorobenzenesulfonyloxy group, a methylbenzenesulfonyloxy group, an ethylbenzenesulfonyloxy group, a propylbenzenesulfonyloxy group, a methoxybenzenesulfonyloxy group, An ethoxybenzenesulfonyloxy group, a propoxybenzenesulfonyloxy group, an acetaminobenzenesulfonyloxy group, etc., or a substituted or unsubstituted naphthalenesulfonyloxy group Specific examples of the naphthalene sulfonyloxy group,
Chloronaphthalenesulfonyloxy group, methylnaphthalenesulfonyloxy group, ethylnaphthalenesulfonyloxy group, propylnaphthalenesulfonyloxy group, methoxynaphthalenesulfonyloxy group, ethoxynaphthalenesulfonyloxy group, propoxynaphthalenesulfonyloxy group, acetaminonaphthalenesulfonyloxy group, etc. preferable. Further, examples of the substituted or unsubstituted benzenecarbonyloxy group and the substituted or unsubstituted naphthalenecarbonyloxy group include those in which the substituted or unsubstituted sulfonyloxy group is replaced with a carbonyloxy group. Of these, an acetaminobenzenesulfonyloxy group or an acetaminonaphthalenesulfonyloxy group is preferable. Further, as the monomer having an α, β-unsaturated double bond, specifically, styrene, chlorostyrene, chloromethylstyrene, vinyltoluene,
Examples thereof include styrene-based monomers such as α-methylstyrene, acrylic acid monomers such as methyl acrylate, methyl methacrylate and phenyl methacrylate, vinyl acetate-based monomers such as vinyl acetate and vinyl benzoate, and among them, styrene is preferable. For example, poly (4-hydroxystyrene-styrene) and poly (4-hydroxystyrene-methylstyrene) copolymers obtained from hydroxystyrene and styrene exhibit high resolution and high heat resistance and are suitable. The component (b) has a weight average molecular weight of 5
The range is 000 or less, preferably 4000 or less. When the weight average molecular weight exceeds 5,000, the resolution is significantly reduced.

In the component (A), when the total amount of the component (a) and the component (b) is 100 parts by weight, the component (a) is 50 to 98 parts by weight, preferably 55 to 95 parts by weight,
The component (b) is 50 to 2 parts by weight, preferably 45 to 5 parts by weight. Such a blending ratio is particularly suitable for a chemically amplified negative photoresist composition for thick film.

(B) Compound that Generates Acid by Irradiation with Radiation The component (B) used in the present invention is an acid generator and is not particularly limited as long as it is a compound that directly or indirectly generates an acid by light. However, specifically, 2,4-bis (trichloromethyl) -6- [2- (2-furyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- ( 5-Methyl-2-furyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (5-ethyl-2-furyl) ethenyl] -s-triazine, 2,4- Bis (trichloromethyl) -6- [2- (5-propyl-2-furyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3,5-dimethoxyphenyl) Ethenyl] -s-tria 2,2-bis (trichloromethyl) -6- [2- (3,5-diethoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3 , 5-Dipropoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3-methoxy-5-ethoxyphenyl) ethenyl] -s-triazine, 2,4-
Bis (trichloromethyl) -6- [2- (3-methoxy-5-propoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2-
(3,4-Methylenedioxyphenyl) ethenyl] -s
-Triazine, 2,4-bis (trichloromethyl) -6
-(3,4-methylenedioxyphenyl) -s-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4methoxy) phenyl-s-triazine, 2,4
-Bis-trichloromethyl-6- (2-bromo-4methoxy) phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4methoxy) styrylphenyl-s-triazine, 2, 4-bis-trichloromethyl-6- (3-bromo-4methoxy) styrylphenyl-s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5
-Triazine, 2- (4-methoxynaphthyl) -4,6
-Bis (trichloromethyl) -1,3,5-triazine, 2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2
-[2- (5-Methyl-2-furyl) ethenyl] -4,
6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,5-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5
-Triazine, 2- [2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl)-
1,3,5-triazine, 2- (3,4-methylenedioxyphenyl) -4,6-bis (trichloromethyl)-
1,3,5-triazine, tris (1,3-dibromopropyl) -1,3,5-triazine, tris (2,3-
A halogen-containing triazine compound such as dibromopropyl) -1,3,5-triazine and a halogen-containing triazine compound represented by the following general formula such as tris (2,3-dibromopropyl) isocyanurate;

[0013]

[Chemical 1]

(In the formula, R ^{1 to} R ³ may be the same or different and each represents a halogenated alkyl group)

Α- (p-toluenesulfonyloxyimino) -phenylacetonitrile, α- (benzenesulfonyloxyimino) -2,4-dichlorophenylacetonitrile, α- (benzenesulfonyloxyimino)-
2,6-dichlorophenylacetonitrile, α- (2-
Chlorobenzenesulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile,
A compound represented by the following general formula;

[0016]

[Chemical 2]

(In the formula, R ⁴ is a monovalent to trivalent organic group;
⁵ represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group, and n represents a natural number of 1 to 3. Here, the aromatic compound group refers to a group of a compound exhibiting physical and chemical properties peculiar to an aromatic compound, such as an aromatic hydrocarbon group such as a phenyl group and a naphthyl group,
Heterocyclic groups such as a furyl group and a thienyl group can be mentioned. These may have one or more suitable substituents on the ring, for example, a halogen atom, an alkyl group, an alkoxy group, a nitro group and the like. Further, R ⁵ is particularly preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. In particular, R ⁴ is an aromatic compound group, R ⁵
Compounds in which is a lower alkyl group are preferred. As the acid generator represented by the above general formula, when n = 1, a compound in which R ⁴ is any one of a phenyl group, a methylphenyl group and a methoxyphenyl group and R ⁵ is a methyl group, specifically, α-
(Methylsulfonyloxyimino) -1-phenylacetonitrile, α- (methylsulfonyloxyimino)-
Examples thereof include 1- (p-methylphenyl) acetonitrile and α- (methylsulfonyloxyimino) -1- (p-methoxyphenyl) acetonitrile. When n = 2, specific examples of the acid generator represented by the above general formula include acid generators represented by the following chemical formulas. )

[0018]

[Chemical 3]

Bissulfonyldiazomethanes such as bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane; p -Nitrobenzyl derivatives such as 2-nitrobenzyl toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, nitrobenzyl tosylate, dinitrobenzyl tosylate, nitrobenzylsulfonate, nitrobenzyl carbonate, dinitrobenzyl carbonate; Pyrogallol trimesylate, pyrgallol tritosylate, benzyl tosylate, benzyl sulfonate, N-
Sulfonic acid esters such as methylsulfonyloxysuccinimide, N-trichloromethylsulfonyloxysuccinimide, N-phenylsulfonyloxymaleimide, N-methylsulfonyloxyphthalimide; trifluoromethanesulfonic acid esters such as N-hydroxyphthalimide, N-hydroxynaphthalimide; Diphenyliodonium hexafluorophosphate, (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, bis (p-tert-butylphenyl) iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, (4-methoxyphenyl) diphenylsulfonium trifluoromethane Rmethanesulfonate, (p-tert-butylphenyl) diphenyl Onium salts such as sulfo trifluoromethanesulfonate; benzoin tosylate, alpha-benzoin tosylate such as methyl benzoin tosylate; other diphenyliodonium salts, triphenylsulfonium salts, phenyldiazonium salts,
Examples thereof include benzyl carbonate.

Among the above, as the component (B), the general formula R-SO ₂ O-N = C (CN)-(in the formula, R is substituted or unsubstituted, for example, having 1 to 1 carbon atoms)
A compound having at least two oxime sulfonate groups represented by 8) which are alkyl groups or aryl groups),
Particularly formula _{R-SO 2 O-N =} C (CN) -A-C (CN) = N-
OSO ₂ —R (In the formula, A is a divalent, for example, a substituted or unsubstituted alkylene group having 1 to 8 carbon atoms or an aromatic compound group,
R is preferably a substituted or unsubstituted compound represented by, for example, an alkyl group or aryl group having 1 to 8 carbon atoms. Here, the aromatic compound group refers to a group of a compound having physical and chemical properties peculiar to an aromatic compound, for example, an aromatic hydrocarbon group such as a phenyl group and a naphthyl group, a furyl group, and a thienyl group. And other heterocyclic groups. These may have one or more suitable substituents on the ring, for example, a halogen atom, an alkyl group, an alkoxy group, a nitro group and the like. Further, in the above general formula, it is more preferable that A is a phenylene group and R is, for example, a lower alkyl group having 1 to 4 carbon atoms.

The components (B) are (A) to (C).
0.01 to 5 parts by weight based on 100 parts by weight of the total components,
Preferably, it can be contained in the range of 0.1 to 1 part by weight. If the amount of the component (B) is less than 0.01 part by weight, cross-linking and curing by heat or light will not be sufficiently carried out, and thus the thick film obtained will have poor plating resistance, chemical resistance and adhesion, and the formed bump shape will be If it exceeds 5 parts by weight, development failure may occur during development, which is not preferable. In particular, when the component (B) is contained in the range of 0.1 to 1 part by weight in the thick film chemically amplified negative photoresist composition, various characteristics of the composition are balanced, which is preferable.

(C) Compound that Crosslinks in the Presence of Acid As the component (C) (crosslinking agent) used in the present invention, known crosslinking agents can be mentioned. Amino compounds such as melamine resins and urea resins can be used. , Guanamine resin, glycoluril-
Formaldehyde resin, succinylamide-formaldehyde resin, ethylene urea-formaldehyde resin and the like are used, and particularly, alkoxymethylated amino resin such as alkoxymethylated melamine resin and alkoxymethylated urea resin can be preferably used. The alkoxymethylated amino resin is, for example, a condensate obtained by reacting melamine or urea with formalin in a boiling aqueous solution, methyl alcohol, ethyl alcohol, propyl alcohol,
It can be produced by etherification with a lower alcohol such as butyl alcohol or isopropyl alcohol, and then cooling the reaction solution to cause precipitation. Specific examples of the alkoxymethylated amino resin include methoxymethylated melamine resin, ethoxymethylated melamine resin, propoxymethylated melamine resin, butoxymethylated melamine resin,
Examples thereof include methoxymethylated urea resin, ethoxymethylated urea resin, propoxymethylated urea resin, butoxymethylated urea resin and the like. The alkoxymethylated amino resins may be used alone or in combination of two or more. In particular, the alkoxymethylated melamine resin is preferable because it can form a stable resist pattern with a small dimensional change of the resist pattern with respect to the change of the irradiation amount of radiation. Of these, methoxymethylated melamine resin, ethoxymethylated melamine resin, propoxymethylated melamine resin and butoxymethylated melamine resin are preferable.

The component (C) may be contained in the range of 1 to 30 parts by weight based on 100 parts by weight of the total amount of the components (A) to (C). If the amount of the component (C) is less than 1 part by weight, the resulting thick film may have poor plating resistance, chemical resistance and adhesion, or the formed bump shape may be unfavorable. If the amount exceeds the range, development failure may occur during development, which is not preferable.

Further, in the thick film chemically amplified negative photoresist composition of the present invention, an organic solvent may be appropriately blended in order to adjust the viscosity. Specific examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, propylene glycol monomethyl ether. , Propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monophenyl ether, diethylene glycol Cole dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate , Diethylene glycol monopropyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monophenyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, professional Glycol monopropyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate,
2-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-
Methoxybutyl acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate,
3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4
-Methyl-4-methoxypentyl acetate, acetone, methyl ethyl ketone, diethyl ketone, methylisobutyl ketone, ethyl isobutyl ketone, tetrahydrofuran, cyclohexanone, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, 2-hydroxypropionic acid Methyl, 2
-Ethyl hydroxypropionate, 2-hydroxy-2
-Methyl, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, ethyl-3-propoxypropionate, propyl-3-methoxypropionate, isopropyl- 3-methoxypropionate, ethyl ethoxyacetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isoamyl acetate,
Methyl carbonate, ethyl carbonate, propyl carbonate, butyl carbonate,
Methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, benzyl methyl ether, benzyl ethyl ether, dihexyl ether, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ−
Butyrolactone, benzene, toluene, xylene, cyclohexanone, methanol, ethanol, propanol, butanol, hexanol, cyclohexanol,
Examples thereof include ethylene glycol, diethylene glycol and glycerin. These may be used alone or in combination of two or more. The amount of these solvents used is, for example, 30% by weight to 65% by weight of the solid content in the thick film chemically amplified negative photoresist composition in order to obtain a film thickness of 20 μm or more by using a spin coating method.
A range of weight% is preferable. Solid content of 30% by weight
When the amount is less than the above, it is difficult to obtain a thick film suitable for the material for forming bumps, and when the amount exceeds 65% by weight, the fluidity of the composition is significantly deteriorated and the handling is difficult. Resist film is difficult to obtain.

In addition to the above-mentioned components, the thick film chemically amplified negative photoresist composition of the present invention may contain a secondary or tertiary compound such as triethylamine, tributylamine, dibutylamine or triethanolamine, if necessary. A quencher such as an amine can be included.

Further, in the thick film chemically amplified negative photoresist composition of the present invention, an adhesion aid can be used in order to improve the adhesion to the substrate. A functional silane coupling agent is effective as the adhesion aid used. Here, the functional silane coupling agent means a silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, and an epoxy group, and specific examples include trimethoxysilylbenzoic acid and γ. -Methacryloxypropyltrimethoxysilane,
Vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β
Examples thereof include-(3,4-epoxycyclohexyl) ethyltrimethoxysilane. The blending amount is
It is preferably 20 parts by weight or less with respect to 100 parts by weight of the component (A).

In addition, in the chemically amplified negative photoresist composition for thick film of the present invention, acetic acid, propionic acid, n-butyric acid, iso-butyric acid, n Monocarboxylic acids such as valeric acid, iso-valeric acid, benzoic acid and cinnamic acid; lactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxy Hydroxymonocarboxylic acids such as cinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid and syringic acid; oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid , Hexahydrophthalic acid, phthalic acid, isophthalic acid,
Terephthalic acid, 1,2-cyclohexanedicarboxylic acid,
Polycarboxylic acids such as 1,2,4-cyclohexanetricarboxylic acid, trimellitic acid, pyromellitic acid, cyclopentanetetracarboxylic acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid; itacone anhydride Acid, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarbanilic anhydride, maleic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hymic acid anhydride, 1,2,3,4-butanetetracarboxylic acid , Cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, benzophenonetetracarboxylic acid anhydride,
An acid anhydride such as ethylene glycol bis anhydrous trimellitate or glycerin tris anhydrous trimellitate can also be added. Furthermore, N-methylformamide, N,
N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethylether, dihexylether, acetonylacetone, isophorone, caproic acid, caprylic acid, It is also possible to add a high boiling point solvent such as 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate. . The amount of the solvent used can be adjusted according to the application and the coating method, and is not particularly limited as long as the composition can be uniformly mixed, but is 60 with respect to the obtained composition.
It is not more than 40% by weight, preferably not more than 40% by weight.

Further, a colorant or the like may be added to the thick film chemically amplified negative photoresist composition of the present invention, if necessary. As a colorant, an extender pigment such as alumina white, clay, barium carbonate, barium sulfate; an inorganic substance such as zinc white, lead white, yellow lead, red lead, ultramarine blue, navy blue, titanium oxide, zinc chromate, red iron oxide, carbon black, etc. Pigments; Brilliant Carmine 6B, Permanent Red 6
Organic pigments such as B, permanent red R, benzidine yellow, phthalocyanine blue, and phthalocyanine green; basic dyes such as magenta and rhodamine; direct dyes such as direct scarlet and direct orange; acid dyes such as roselin and methanyl yellow. . These additives are in a range that does not impair the essential properties of the composition, preferably 50% by weight or less based on the resulting composition.

The chemical amplification type negative photoresist composition for thick film of the present invention may be prepared by mixing and stirring in a usual manner, and if necessary, a dissolver, a homogenizer, a 3
You may disperse and mix using a disperser, such as this roll mill. Further, after mixing, it may be filtered using a mesh, a membrane filter or the like.

The composition of the present invention is preferably applied as a thick film on a substrate, but its application range is not limited to this, and for example, when etching various substrates such as copper, chromium, iron and glass substrates. It can also be used as a protective film or a resist for semiconductor production. Bump formation using the composition of the present invention as a thick resist film is performed as follows. (1) Formation of coating film: A solution of the composition prepared as described above is applied onto a substrate having a predetermined wiring pattern, and the solvent is removed by heating to form a desired coating film. As a coating method on the substrate to be processed, a spin coating method, a roll coating method, a screen printing method, an applicator method or the like can be adopted. The pre-baking conditions for the coating film of the composition of the present invention are usually 70 to 130 ° C., preferably 80 to 120 ° C., although they vary depending on the type of each component in the composition, the compounding ratio, the coating film thickness and the like. ~
It is about 60 minutes. (2) Radiation irradiation: Radiation, for example, a wavelength of 300 to 500 n is applied to the obtained coating film through a mask having a predetermined pattern.
By irradiating m ultraviolet rays or visible rays, only the wiring pattern portion forming the bumps is exposed. A low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an argon gas laser, etc. can be used as a radiation source of these radiations. Here, the radiation means ultraviolet rays, visible rays, far ultraviolet rays, X-rays, electron beams and the like. The radiation dose varies depending on the type of each component in the composition, the blending amount, the film thickness of the coating film, etc., but is 100 to 2000 mJ / cm ² when using an ultra-high pressure mercury lamp, for example. (3) Heating: After exposure, heating is performed using a known method. (4) Development: As a developing method after irradiation with radiation, an alkaline aqueous solution is used as a developing solution to dissolve unnecessary portions,
Remove and leave only the radiation-exposed portion. As the developing solution, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate,
Ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8 An aqueous solution of an alkali such as -diazabicyclo [5,4,0] -7-undecene and 1,5-diazabicyclo [4,3,0] -5-nonane can be used. Further, an aqueous solution prepared by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the aqueous solution of the alkalis can be used as a developing solution. Development time depends on the type of each component of the composition,
Usually 1 depending on the blending ratio and the dry film thickness of the composition
The developing time may be any of a puddle method, a dipping method, a paddle method, a spray developing method and the like. After the development, washing with running water is carried out for 30 to 90 seconds, followed by drying using an air gun, an oven or the like.

The plating method is not particularly limited, and various conventionally known plating methods can be adopted. As the plating solution, solder plating or copper plating solution is preferably used.

The thickness of the chemically amplified negative photoresist composition for thick film of the present invention is 20 to 150 μm,
Preferably 30-120 μm, more preferably 40-9
The range is preferably 0 μm. If the film thickness is less than 20 μm or more than 150 μm, the performance required for the present composition cannot be satisfied.

[0033]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, unless otherwise specified, parts are parts by weight and% is% by weight.

<Synthesis of (A) Alkali-Soluble Resin> Synthesis Example 1 m-cresol and p-cresol were mixed at a weight ratio of 60:40, formalin was added thereto, and an oxalic acid catalyst was used by a conventional method. Condensation gave a cresol novolac resin. This resin was subjected to fractionation treatment to cut the low molecular weight region to obtain a novolak resin having a weight average molecular weight of 10,000. This resin is referred to as novolac resin A1.

Synthesis Example 2 Formalin was added to m-cresol and condensed by an ordinary method using an oxalic acid catalyst to obtain m-cresol novolak resin. This resin was subjected to a fractionation treatment to cut the low molecular region to obtain a novolak resin having a weight average molecular weight of 6000. This resin is referred to as novolac resin A2.

Example 1 (a) 90 parts of novolak resin A1, 10 parts of (b) hydroxystyrene homopolymer (Mw2500) (manufactured by Nippon Soda Co., Ltd., trade name UP-2500), (B) represented by the following formula. After dissolving 0.5 part of an acid generator and 10 parts of hexamethoxymethylated melamine (manufactured by Sanwa Chemical Co., Ltd., trade name Nilak Mw-100) as a crosslinking agent (C) in a solvent of 150 parts of propylene glycol methyl ether acetate, Filtration was performed using a membrane filter having a pore size of 1.0 μm to prepare a negative photoresist composition. Using the composition, the following characteristic evaluations were performed. The results are shown in Table 1.

[0037]

[Chemical 4]

Example 2 A negative photoresist composition was prepared in the same manner as in Example 1 except that the novolak resin A2 was used as the component (a). Using the composition, the following characteristic evaluations were performed.
The results are shown in Table 1.

Example 3 As components (a) and (b), 50 parts of (a) novolak resin A2 and (b) hydroxystyrene homopolymer (Mw2500) (Nippon Soda Co., Ltd., trade name UP-25)
A negative photoresist composition was prepared in the same manner as in Example 1 except that 50 parts of (00) was used. Using the composition, the following characteristic evaluations were performed. The results are shown in Table 1.

Example 4 A negative resist composition was prepared in the same manner as in Example 2 except that 1 part of tris (2,3-dibromopropyl) isocyanurate was used as the component (B). Using the composition, the following characteristic evaluations were performed. The results are shown in Table 1.

Example 5 A negative resist composition was prepared in the same manner as in Example 2, except that the component (B) was replaced with 1 part of the acid generator represented by the following formula. Using the composition, the following characteristic evaluations were performed. The results are shown in Table 1.

[0042]

[Chemical 5]

Comparative Example 1 A negative resist composition was prepared in the same manner as in Example 1 except that the homopolymer of (b) hydroxystyrene was not used. Using the composition, the following characteristic evaluations were performed. The results are shown in Table 2.

Comparative Example 2 Instead of the acid generator (B) and the crosslinking agent (C), 2 mol of 1,2-naphthoquinonediazide-4-sulfonyl chloride was used with respect to 1 mol of the compound represented by the following chemical formula (1). A negative resist composition was prepared in the same manner as in Example 1 except that 20 parts of the photoreaction initiator reacted with was used. Using the composition, the following characteristic evaluations were performed. The results are shown in Table 2.

[0045]

[Chemical 6]

Evaluation Method of Properties Compatibility The above composition was mixed and stirred at room temperature for 12 hours, and the dissolved state was visually observed immediately after stirring and 12 hours after stirring. The dispersion state was judged according to the following evaluation criteria. ◯: It was visually confirmed that the composition was uniformly dispersed after stirring for 12 hours. (Triangle | delta): The composition disperse | distributed uniformly after stirring for 12 hours, but phase-separated by leaving still for a long time. X: The composition is not uniformly dispersed after stirring for 12 hours.

Coating Property The composition was coated on a 5-inch gold sputtering wafer using a spinner at 1000 rpm for 25 seconds, and then heated at 110 ° C. for 6 minutes on a hot plate. The formed film surface was visually observed and the applicability was judged according to the following evaluation criteria. ◯: The obtained coating film is uniform and uniform. X: The obtained coating film has unevenness such as pinholes and cissing.

Developability / Resolution A spinner was used on a 5-inch silicon wafer.
1800 in the case of a coating film having a film thickness of about 20 μm
It was formed by applying 25 minutes at rpm and prebaking at 110 ° C. for 6 minutes on a hot plate. Also, the film thickness is about 65
In the case of a coating film of μm, after coating at 800 rpm for 25 seconds,
It was pre-baked on a hot plate at 110 ° C. for 1 minute, further applied at 800 rpm for 25 seconds, and then pre-baked on a hot plate at 110 ° C. for 9 minutes to be formed. Also,
For a coating film with a thickness of about 120 μm, 25 at 800 rpm
After applying for 2 seconds, pre-bake on a hot plate at 110 ° C. for 1 minute, then apply at 800 rpm for 25 seconds, then 1
It was formed by pre-baking at 10 ° C. for 1 minute, application at 800 rpm for 25 seconds, and pre-baking at 110 ° C. for 13 minutes.
Next, through the pattern mask for resolution measurement, a stepper (Ultratech, Saturn Spectrum 3 Wafer Stepp
er) is used to divide one coated substrate into 20
The ultraviolet exposure was performed stepwise in the range of 0 to 3000 mJ / cm ² . After exposure, heat at 110 ° C. for 6 minutes,
It was developed with a developing solution (trade name PMER series, P-7G, manufactured by Tokyo Ohka Co., Ltd.). After that, it was washed with running water and blown with nitrogen to obtain a patterned cured product. This was observed with a microscope, and the resolution was judged according to the following evaluation criteria. ◯: When a 5 μm square hole pattern was resolved at any of the above exposure amounts and no residue was observed. X: When the hole pattern of 5 μm square is not resolved or a residue is observed. At this time, the aspect ratio (aspect ratio = resist height on pattern / resist width on pattern) was also measured.

Plating resistance: A substrate having a patterned cured product obtained by "development / resolution evaluation" was used as a test body, which was subjected to an ashing treatment with oxygen plasma and then immersed in a copper sulfite plating solution at 40 ° C. for 3 hours, It was washed with running water to obtain a test sample. Using an optical microscope or an electron microscope, observe the state of bumps and patterned cured products formed on the sample to be processed, and check the resistance of the patterned cured products to the plating solution, the shape of the formed pump, and the cured pattern. The resistance of the product to the plating treatment process was judged according to the following evaluation criteria. ◯: There is no particular change in the state of the formed bumps and the patterned cured product. X: The patterned cured product has cracks, bulges or chips, or the surface of the patterned cured product is rough.

A test specimen was obtained in the same operation as the bump shape “plating resistance evaluation”,
The state of the formed bumps and the patterned cured product was observed using an optical microscope or an electron microscope, and the shape of the formed bumps was judged according to the following evaluation criteria. When the bump shape is good, the angle between the substrate and the bump and the error ratio with respect to the mask size were measured. ◯: The shape of the bump depends on the patterned cured product (following)
And good. Poor: The shape of the pump does not depend on the patterned cured product and bulges occur.

Peelability A substrate having a patterned cured product obtained in "Development / resolution evaluation" was used as a test body and immersed in a peeling solution (Tokyo Ohka Stripper 710) under stirring at 70 ° C for 10 minutes. After that, a rinse solution was washed with alcohol to remove the patterned cured product, which was visually observed or observed with an optical microscope and evaluated according to the following criteria. ◯: No residue of the patterned cured product is observed. X: Residue of the patterned cured product was recognized.

A film having a thickness of about 40 μm was formed on a photosensitive 5 inch silicon wafer, and a stepper (manufactured by Ultratech, Saturn Spectrum 3Wafer St
epper) was used to divide one coated substrate, and each was subjected to ultraviolet exposure stepwise in the range of 200 to 10,000 mJ / cm ² . This was developed with a developing solution (trade name PMER series, P-7G, manufactured by Tokyo Ohka Co., Ltd.). After this,
It was washed with running water and blown with nitrogen to obtain a patterned cured product.
This was observed under a microscope, and the exposure amount at which a 5 μm square hole pattern was resolved and no residue was observed was measured.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

According to the present invention, it is suitable for forming a thick film suitable for forming bumps, rewirings, and metal posts, which has high sensitivity and good plating resistance and is used in CSP manufacturing technology. Provided are a chemically amplified negative photoresist composition for thick film, a photoresist base material, and a bump forming method using the same.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/60 H01L 21/92 604B 604S (72) Inventor Toshiki Okui 150 Nakamaruko Nakahara-ku, Kawasaki-shi, Kanagawa East Kyohka Kogyo Co., Ltd. (72) Inventor Hiroshi Komano 150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa F-Term (Reference) 2H025 AA01 AB15 AB16 AB17 AC01 AC04 AC05 AC06 AC08 AD01 BE00 CB17 CB29 CB45 CC20 FA03 FA12 FA17 FA43 4J031 AA13 AA20 AA44 AA45 AB01 AD03 AE07 AE08 AF22

Claims (9)

[Claims] 1. A chemically amplified negative photoresist composition containing (A) an alkali-soluble resin, (B) a compound that generates an acid upon irradiation with radiation, and (C) a compound that undergoes a crosslinking reaction in the presence of an acid. , The component (A) is
(A) A thick film chemistry comprising a mixture of a novolac resin having a weight average molecular weight of 5,000 to 10,000 and (b) a polymer having at least a hydroxystyrene structural unit and having a weight average molecular weight of 5,000 or less. Amplified negative photoresist composition. 2. The thick film according to claim 1, wherein the component (a) comprises m-cresol novolac resin obtained by condensing m-cresol and aldehydes in the presence of an acid catalyst. Chemically amplified negative photoresist composition for use. 3. In the component (A), when the total amount of the component (a) and the component (b) is 100 parts by weight, the component (a) is 50 to 98 parts by weight, and the component (b) is 50 to 2 parts by weight. 2. The chemically amplified negative photoresist composition for thick film according to claim 1, which is a part. 4. The oxime represented by the formula (B) is represented by the general formula R—SO ₂ O—N═C (CN) — (wherein R is a substituted or unsubstituted alkyl group or aryl group). The chemical amplification type negative photoresist composition for thick film according to claim 1, which is a compound having at least two sulfonate groups. 5. The component (B) has the general formula R—SO ₂ O—N═C (CN) —AC (CN) = N—.
The chemical amplification for thick film according to claim 4, which is a compound represented by OSO ₂ -R (wherein A is a divalent organic group, and R is a substituted or unsubstituted alkyl group or aryl group). Negative photoresist composition. 6. The chemically amplified negative photoresist composition for thick film according to claim 5, wherein A in the general formula of component (B) is a phenylene group and R is a lower alkyl group. 7. When the total amount of the component (A), the component (B) and the component (C) is 100 parts by weight, the amount of the component (B) is 0.
The chemical amplification negative photoresist composition for thick film according to claim 1, which is 1 to 1 part by weight. 8. A negative photoresist base material having a substrate and a negative photoresist layer provided thereon,
The photoresist base material, wherein the negative photoresist layer is composed of the chemically amplified negative photoresist composition for thick film according to any one of claims 1 to 7, and has a film thickness of 20 to 150 µm. . 9. The method according to any one of claims 1 to 7 on a base material of an electronic component.
The chemical amplification type negative photoresist composition for thick film according to any one of 1. above was applied, and the resulting coating film was sequentially subjected to selective exposure, heat treatment and development treatment to form a negative resist pattern. Then, a bump forming method is characterized in that a plating process is performed using this resist pattern as a mask.