JPH06130664A - Negative photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain a negative pattern with high sensitivity and high resolution by using specified polyamide acid ester, naphthoquinone diazide compd. and photopolymn. initiator as essential components. CONSTITUTION:This compsn. consists of polyamide acid ester expressed by formula I, naphthoquinone diazide compd., and photopolymn. initiator. In the formula I, R1 is a tervalent or quadrivalent org. group, R2 is a bivalent org. group, R3 is expressed by formula II, R4 is expressed by the formula II or -CH3 or -C2H5, R5 is a 2- to 6-valent org. group, and R6 is H or CH3. R1-R6 are indepenent and may be same or different. (l), (m), (n) are 0 or 1, (p) is integer of 1 to 5, and (x), (y), (z) are percentages of the respective structural unit satisfying 0<x, y<100, 0<z<80 and x+y+z=100. The polamide acid ester expressed by the formula I shows high reacitivity and the hardened material has good heat resistance, mechanical characteristics and electric characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive polyimide resin composition capable of obtaining a negative pattern having high sensitivity and high resolution.

[0002]

2. Description of the Related Art Conventionally, a polyimide having excellent heat resistance and excellent electrical insulation and mechanical strength has been used for a surface protective film and an interlayer insulating film of a semiconductor element. Recently, a technique for imparting photosensitivity to polyimide itself has been attracting attention in order to simplify the complicated process. For example, the following formula

[0003]

[Chemical 2]

There is known a polyimide precursor composition (for example, Japanese Examined Patent Publication No. 55-41422) in which a photosensitive group is provided with an ester group having a structure as shown in FIG. All of these are dissolved in a suitable organic solvent, applied in a varnish state, dried, and then irradiated with ultraviolet rays through a photomask,
A polyimide film is formed by developing and rinsing to obtain a desired pattern and further heat treatment.

The use of a photosensitized polyimide not only has the effect of simplifying the pattern forming process, but it is also safe and excellent in pollution because it does not require the use of a highly toxic etching solution. It is expected that sexualization will become an even more important technology in the future. However, in a negative-type photosensitive polyimide resin composition obtained by adding a conventional photopolymerization initiator and a photosensitizer to a polyimide precursor provided with such an ester group, it was difficult to simultaneously satisfy both characteristics of sensitivity and resolution. .

[0006]

The object of the present invention is to provide a naphthoquinone diazide compound, a polyamic acid ester in which a mono- or polyfunctional photosensitive group and a lower alcohol are covalently introduced into a carboxyl group in a polyamic acid. By providing a photopolymerization initiator, it is intended to provide a photosensitive resin composition capable of obtaining a negative pattern having high sensitivity and high resolution.

[0007]

The present invention is based on the formula (1):

[0008]

[Chemical 3]

And a polyamic acid ester represented by (B)
It is a negative photosensitive resin composition comprising a naphthoquinone diazide compound and (C) a photopolymerization initiator.

[0010]

The polyamic acid ester represented by the formula (1) used in the present invention exhibits high reactivity, and the cured product has good heat resistance, mechanical properties and electrical properties.

In the formula (1), R ₁ is introduced from a compound having a trivalent or tetravalent organic group, and usually aromatic tetracarboxylic acid or its derivative and aromatic tricarboxylic acid or its derivative are mainly used. To be done. For example, trimellitic anhydride, pyromellitic dianhydride, benzene-1,
2,3,4-tetracarboxylic dianhydride, 3,3 ′,
4,4'-benzophenone tetracarboxylic dianhydride,
2,2 ', 3,3'-benzophenone tetracarboxylic dianhydride, 2,3,3', 4'-benzophenone tetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride Anhydrous, naphthalene-1,2,5,6
-Tetracarboxylic dianhydride, naphthalene-1,2,
4,5-tetracarboxylic dianhydride, naphthalene-1,
4,5,8-Tetracarboxylic acid dianhydride, naphthalene-
1,2,6,7-tetracarboxylic dianhydride, 4,8-
Dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride,
4,8-Dimethyl-1,2,3,5,6,7-hexahydronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,5 8
-Tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,
2,3,6,7-tetrachloronaphthalene-1,4
5,8-Tetracarboxylic acid dianhydride, 1,4,5,8-
Tetrachloronaphthalene-2,3,6,7-tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyltetracarboxylic dianhydride, 2,2', 3,3'-diphenyltetracarboxylic Acid dianhydride, 2,3,3 ', 4'-diphenyltetracarboxylic acid dianhydride, 3,3 ", 4
4 "-p-terphenyltetracarboxylic dianhydride,
2,2 ", 3,3" -p-terphenyltetracarboxylic dianhydride, 2,3,3 ", 4" -p-terphenyltetracarboxylic dianhydride, 2,2-bis (2,2 3-dicarboxyphenyl) -propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (3 , 4-Dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl)
Methane dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane Dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, berylene-2,3,8,9-tetracarboxylic dianhydride,
Perylene-3,4,9,10-tetracarboxylic dianhydride, perylene-4,5,10,11-tetracarboxylic dianhydride, perylene-5,6,11,12-tetracarboxylic dianhydride , Phenanthrene-1,2,7,8-tetracarboxylic dianhydride, phenanthrene-1,2,
6,7-Tetracarboxylic acid dianhydride, phenanthrene-
1,2,9,10-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, Examples thereof include, but are not limited to, pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride and thiophene-2,3,4,5-tetracarboxylic acid dianhydride. In addition, when using one type, 2
It may be a mixture of more than one kind.

In the formula (1), R ₂ is a divalent organic group, and an aromatic diamine and / or its derivative is usually used for its introduction. For example, m-phenylene-diamine, 1-isopropyl-2,4-phenylene-diamine, p-phenylene-diamine, 4,4'-diamino-diphenylpropane, 3,3'-diamino-diphenylpropane,
4,4′-diamino-diphenylethane, 3,3′-diamino-diphenylethane, 4,4′-diamino-diphenylmethane, 3,3′-diamino-diphenylmethane, 4,4′-diamino-diphenylsulfide, 3,
3′-diamino-diphenyl sulfide, 4,4′-diamino-diphenyl sulfone, 3,3′-diamino-diphenyl sulfone, 4,4′-diamino-diphenyl ether, 3,3′-diamino-diphenyl ether, benzidine, 3, 3'-diamino-biphenyl, 3,3 '
-Dimethyl-4,4'-diamino-biphenyl, 3,
3'-dimethoxy-benzidine, 4,4 "-diamino-
p-terphenyl, 3,3 ″ -diamino-p-terphenyl, bis (p-amino-cyclohexyl) methane, bis (p-β-amino-t-butylphenyl) ether,
Bis (p-β-methyl-δ-aminopentyl) benzene, p-bis (2-methyl-4-amino-pentyl) benzene, p-bis (1,1-dimethyl-5-amino-pentyl) benzene, 1 , 5-diamino-naphthalene,
2,6-diamino-naphthalene, 2,4-bis (β-amino-t-butyl) toluene, 2,4-diamino-toluene, m-xylene-2,5-diamine, p-xylene-2,5- Diamine, m-xylylene-diamine, p-
Xylylene-diamine, 2,6-diamino-pyridine,
2,5-diamino-pyridine, 2,5-diamino-1,
3,4-oxadiazole, 1,4-diamino-cyclohexane, piperazine, methylene-diamine, ethylene-diamine, propylene-diamine, 2,2-dimethyl-propylene-diamine, tetramethylene-diamine,
Pentamethylene-diamine, hexamethylene-diamine, 2,5-dimethyl-hexamethylene-diamine, 3
-Methoxy-hexamethylene-diamine, heptamethylene-diamine, 2,5-dimethyl-heptamethylene-diamine, 3-methyl-heptamethylene-diamine, 4,
4-dimethyl-heptamethylene-diamine, octamethylene-diamine, nonamethylene-diamine, 5-methyl-nonamethylene-diamine, 2,5-dimethyl-nonamethylene-diamine, decamethylene-diamine, 1,10
-Diamino-1,10-dimethyl-decane, 2,11-
Diamino-dodecane, 1,12-diamino-octadecane, 2,12-diamino-octadecane, 2,17-diamino-icosane, diaminosiloxane, 2,6-diamino-4-carboxylic benzene, 3,3'-diamino- Examples thereof include, but are not limited to, 4,4′-dicarboxylic benzidine. In use, one kind or a mixture of two or more kinds may be used.

In the formula (1), R ₃ is a photosensitive group having 1 to 5 acrylic (methacryl) groups, and R ₄ is a photosensitive group having 1 to 5 acryl (methacryl) groups or a methyl group or ethyl group. It is a base. When R ₃ and R _{4 have} an acrylic (methacrylic) group of 0, a crosslinked structure cannot be obtained, which is not preferable. Further, a hexafunctional or higher-functional acryl (methacryl) group is not preferable because it is industrially difficult to produce and the compatibility is lowered because the molecular weight becomes large. Examples of the compound for introducing R ₃ and R ₄ include pentaerythritol triacrylate, pentaerythritol trimethacrylate,
Pentaerythritol acrylate dimethacrylate,
Pentaerythritol diacrylate methacrylate,
Dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, glycerol diacrylate, glycerol dimethacrylate, glycerol acrylate methacrylate, trimethylolpropane diacrylate, 1,3-diacryloylethyl-5-hydroxyethyl isocyanurate, 1,3-di Methacrylate-5-hydroxyethyl isocyanurate, ethylene glycol modified pentaerythritol triacrylate, propylene glycol modified pentaerythritol triacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, glycidyl Methacrylate,
Examples thereof include, but are not limited to, glycidyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, polyethylene glycol-modified methacrylate, polyethylene glycol-modified acrylate, polypropylene glycol-modified acrylate, polypropylene glycol-modified methacrylate, and the like. In using these, one kind or a mixture of two or more kinds may be used. The methyl group or ethyl group of R ₄ is usually derived from methanol, ethanol or the like.

[0014] polyamic acid ester represented by the formula (1) used in the present invention, the proportion of the structural unit R ₃ is introduced into the carboxyl group is x, a part in R _3, R ₄ is introduced into the remaining The ratio of the structural units is y, the ratio of the structural units in which the carboxyl group is substituted with R ₄ is z, and three types of structural units are mixed. 0 <x, y <10 respectively
0, 0 <z <80, and x + y + z = 100 are satisfied, and x, y, and z represent the percentage of each structural unit. When R ₄ is -CH ₃ or -C ₂ H ₅ is, z is 80
When it is above, the amount of the photosensitive group is small and the sensitivity is low and the practicality is low.

The polyamic acid ester (A) in the present invention is usually synthesized as follows. First, a compound having an alcohol group for introducing the polyfunctional photosensitive groups R ₃ and R ₄ is dissolved in a solvent, and excess acid anhydride or its derivative is reacted with this. After that, the remaining carboxyl group and acid anhydride group can be reacted with diamine to synthesize.

The naphthoquinonediazide compound (B) in the present invention is a compound conventionally used as a photosensitizer for a positive photoresist. The mechanism of action is
When exposed to light, the naphthoquinonediamide compound undergoes intramolecular rearrangement to produce indenecarboxylic acid, and as a result, it becomes soluble in an alkaline aqueous solution. In other words, it is a so-called positive type photosensitizer that dissolves in a developing solution when exposed to light. An example of using this quinonediazide in a polyimide is a polyamic acid to which naphthoquinonediazide is added (Japanese Patent Laid-Open No. 52-
No. 13315), a solvent-soluble polyimide to which naphthoquinonediazide is added (JP-A-63-13032).
JP-A No. 3-115461) and polyamic acid ester to which naphthoquinonediazide is added. All of these use naphthoquinonediazide as a photosensitizer for a positive photosensitive resin. is the current situation. However, when the polyamic acid ester represented by the formula (1) of the present invention is used together with a photopolymerization initiator, an excellent sensitizing effect is exhibited and a negative type pattern having a high resolution is obtained. The reason why this synergistic effect is developed is not clear so far. Examples of naphthoquinone diazide include

[0017]

[Chemical 4]

[0018]

[Chemical 5]

[0019]

[Chemical 6]

[0020]

[Chemical 7]

Examples thereof include, but are not limited to:

As the photopolymerization initiator in the present invention, the following compounds used for general UV curing resins can be used. Benzyl, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoyl benzoic acid, methyl benzoyl benzoate, 4-benzoyl-4′-methyldiphenyl sulfide, benzyl dimethyl ketal,
2-n-butoxyethyl-4-dimethylaminobenzoate, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-dimethylaminoethylbenzoate, p-dimethylaminobenzoic acid Ethyl acid, isoamyl p-dimethylaminobenzoate, 3,3′-dimethyl-4-methoxybenzophenone, 2,4-dimethylthioxanthone, 1-
(4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- (4- Isopropylphenyl) -2-hydroxy-2-methylpropane-1
-One isopropyl thioxanthone, methyl benzoyl formate, 2-methyl-1- [4 (methylthio) phenyl] -2-morpholinopropanone-1, N-phenylglycine, 1-phenyl-1 ', 2-propanedione Examples include, but are not limited to, 2- (O-ethoxycarbonyl) oxime, tetra (t-butylperoxycarbonyl) benzophenone, and the like. In addition, these may be individual or may mix several.

Further, in the present invention, a photopolymerizable monomer having a carbon-carbon double bond may be added for the purpose of further improving the sensitivity. Specific examples thereof include trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene. Glycol diacrylate, 2-hydroxyethyl acrylate, isobornyl acrylate, N-methylol acrylamide, N, N-
Dimethyl acrylamide and acrylates of these and those obtained by changing acrylamide to methacrylate or methacrylamide can be used.

To the negative photosensitive resin composition according to the present invention, an adhesion aid, an inhibitor, a leveling agent and other various fillers may be added.

In the method of using the negative photosensitive resin composition according to the present invention, first, the composition is applied to a suitable support such as a silicon wafer, a ceramic or an aluminum substrate. The coating method is spin coating using a spinner, spray coating using a spray coater, dipping, printing, roll coating, or the like. Next, after prebaking at a low temperature of 60 to 80 ° C. to dry the coating film, a desired pattern shape is irradiated with actinic rays. The actinic rays include X-rays, electron rays, ultraviolet rays,
Visible light and the like can be used, but those having a wavelength of 200 to 500 nm are preferable.

Next, the unirradiated portion is dissolved and removed with a developing solution to obtain a negative relief pattern. As the developing solution, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, or the like,
Methanol, isopropyl alcohol, water, alkaline aqueous solution, etc. may be used alone or as a mixture. As a developing method, a method such as spraying, paddle, dipping, or ultrasonic wave can be used.

Next, the relief pattern formed by development is rinsed. As the rinse liquid, methanol, xylene, ethanol, isopropyl alcohol, butyl acetate, water or the like is used. Next, heat treatment is performed to form an imide ring, and a final pattern having high heat resistance is obtained.

The photosensitive resin composition according to the present invention is useful not only for semiconductors, but also as an interlayer insulating film of a multilayer circuit, a cover coat of a flexible copper clad board, a solder resist film, a liquid crystal alignment film and the like.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 65.5 g (0.30 mol) of pyromellitic dianhydride and 225.5 g (0.70 mol) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride were mixed with glycerol dihydrate. After esterifying the carboxyl group with 456.5 g of methacrylate (2.00 mol), 170.2 g (0.85 mol) of 4,4′-diaminodiphenyl ether was used as a condensing agent for dicyclohexylcarbodiimide to prepare a polyamic acid ester copolymer. Obtained. The dicyclohexylurea was filtered off and then reprecipitated in ethanol, the solid matter was filtered and dried under reduced pressure. To 100 parts by weight of this polyamic acid ester, 6 parts by weight of Michler's ketone, 10 parts by weight of tetraethylene glycol diacrylate, 3 parts by weight of a naphthoquinone diamide compound represented by the following formula (2) and 0.1 part by weight of methyl ether hydroquinone were added to N-methylpyrrolidone. Ki 10
It was dissolved in 0 part by weight to obtain a photosensitive resin composition.

[0030]

[Chemical 8]

The obtained solution was applied onto a silicon wafer with a spinner so as to have a thickness of 10 μm, and dried at 70 ° C. for 1 hour by a dryer. The obtained film was irradiated with an ultra-high pressure mercury lamp through a resolution evaluation mask manufactured by Toppan Printing. Then N-methyl-2-pyrrolidone 5
0 wt%, with xylene 50% by weight of the developer, the developer in a spray, was further were rinsed with isopropyl alcohol, resolved to 15μm even exposure 800 mJ / cm ^2, it was found that a high resolution. Example 2 The glycerol dimethacrylate used in Example 1 was reduced to 228.3 g (1.0 mol), and 32.0 g (1.0 mol) of methanol was added and reacted. Other than this, a resin composition was obtained by the same method and the same evaluation was carried out. Even when the exposure amount was 1,000 mJ / cm ² , the resolution was up to 12 μm.
It turned out to be a high resolution. Example 3 Glycerol dimethacrylate used in Example 1 was replaced with 2-hydroxyethylmethacrylate 26.
When the amount was changed to 0.3 g (2 mol) and a resin composition was obtained and the same evaluation was carried out, it was 18 even when the exposure amount was 1,000 mJ / cm ^2.
It was resolved up to μm and was found to have high resolution. Example 4 The naphthoquinonediazide compound (2) used in Example 1 was changed to 1 part by weight of the naphthoquinonediazide compound represented by the following formula (3), and a resin composition was obtained by the same method, and the same evaluation was conducted. The exposure amount was 700
Even with mJ / cm ² , resolution was up to 10 μm, and it was found that the resolution was high.

[0032]

[Chemical 9]

Example 5 The naphthoquinonediazide compound (2) used in Example 1 was changed to 1 part by weight of the naphthoquinonediazide compound represented by the following formula (4), and a resin composition was obtained by the same method, When the same evaluation was performed, the exposure amount was 800
Even with mJ / cm ² , resolution was achieved up to 18 μm and it was found that the resolution was high.

[0034]

[Chemical 10]

Comparative Example 1 When the naphthoquinonediazide compound (2) added in Example 1 was omitted and evaluated, it was 1,500 mJ.
A good pattern was not obtained even when irradiated with light of / cm ² . Comparative Example 2 The naphthoquinonediazide compound (2) added in Example 1 was omitted, Michler's ketone was increased from 6 parts by weight to 10 parts by weight, and tetraethylene glycol diacrylate was increased to 20 parts by weight. When it was carried out, a pattern was formed with an exposure dose of 1,200 mJ / cm ² , but the resolution was poor at 40 μm and there was a problem in practicality. Comparative Example 3 When the Michler's ketone added in Example 1 was omitted and the evaluation was performed in the same manner, both the exposed and unexposed areas were dissolved during development and no pattern was obtained.

[0036]

EFFECTS OF THE INVENTION Conventionally, a technique for introducing a photosensitive group into a carboxyl group of a polyamic acid in an ester form has been known. However, if a conventional photoinitiator is added to such a technique, both sensitivity and resolution characteristics can be obtained. It was difficult to meet at the same time.
In the present invention, a monofunctional or polyfunctional photosensitive group in the carboxyl group of the polyamic acid, a polyamic acid ester in which a lower alcohol is covalently introduced, a naphthoquinonediazide compound and a photopolymerization initiator are added to thereby obtain sensitivity and resolution. Was able to be greatly improved at the same time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/027

Claims (1)

[Claims] 1. A polyamic acid ester represented by the following formula (1): A negative photosensitive resin composition comprising (B) a naphthoquinonediazide compound and (C) a photopolymerization initiator as essential components.