JP2000206684A - Negative radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the negative radiation-sensitive resin composition high in sensitivity and having heat resistance and capable of obtaining superior pattern forms by incorporating specified resins and specified compounds. SOLUTION: The radiation-sensitive resin composition contains the alkali- soluble resin, the radiation-sensitive acid generator, methoxymethylated amino resin, and the organic amino compound, and the alkali-soluble resin is a phenol novolak resin obtained from a phenolic compound containing >=75 weight %m- cresol and the phenolic compound represented by formula I and the like, and the above acid generator is a triazine compound represented by formula II. The methoxymethylated amino resin is such a melamine resin or urea resin. The organic amino compound is the one represented by formula III. In formulae II and III, R1 is an H atom or alkyl group or the like; and R2 is a >=4C alkyl or aralkyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a negative-type radiation-sensitive resin composition which is particularly useful as a photoresist for manufacturing a liquid crystal display, and more particularly to a radiation-sensitive resin composition having a high sensitivity to light, The present invention relates to a negative radiation-sensitive resin composition having high sensitivity, high resolution, excellent pattern shape, and high heat resistance.

[0002]

2. Description of the Related Art In recent years, in the production of liquid crystal display devices (LCDs), while the substrate size has been increased, it has been required to improve the throughput and to increase the definition of the display. In order to meet such demands, it is effective to increase the sensitivity of the photoresist and to improve the resolution. On the other hand, LC
Since photoresists for manufacturing D are required to have various properties such as adhesion and coating characteristics, it is difficult to use photoresists for manufacturing semiconductors as they are for manufacturing LCDs. Development is required. Recently, in the production of liquid crystal display devices, L
It has been desired to develop a negative resist for LCD production that satisfies both the characteristics and high heat resistance of positive photoresist for CD production.

With respect to the negative-type radiation-sensitive composition, JP-A-1-293339 discloses a photoresist composition containing alkoxymethylmelamine. JP-A-4-136858 and JP-A-4-136858 disclose a composition containing a mixture of polyhydroxystyrene and a triazine acid generator, and JP-A-4-136860 defines the amount of m-cresol in the raw material. A negative resist composition containing a novolak resin and a triazine compound is disclosed. JP-A-6-289614 discloses a negative resist composition containing a triazine compound and a benzophenone compound. JP 7
No. 1404063 discloses a negative resist composition containing a photosensitive s-triazine compound and esters of propylene glycol monoalkyl ether as a solvent. JP-A-62-164045 discloses that 2
A negative resist composition comprising a halogenated organic compound that absorbs actinic radiation in a wavelength range of 10 to 299 nm is disclosed. However, only the techniques disclosed in these publications cannot satisfy all of the high sensitivity, high heat resistance, and high resolution required for a negative resist for manufacturing a liquid crystal display. Regarding a chemically amplified negative resist containing an organic amine compound, JP-A-8-179508 describes a negative resist composition containing a trialkylamine as an amine compound. Proceedings of the SPIE Microlithography Symposium No. 3333
Volume 644 discusses the addition of amine compounds to a negative resist for KrF (248 nm) exposure. JP-A-10-
186660 discloses a negative resist composition containing an organic amine and an organic carboxylic acid compound.
However, such a composition is not suitable for g-line (436 nm) and h-line (405 nm) used in the production of liquid crystal displays.
Since they do not have sufficient sensitivity, it is difficult to realize high resolution and high heat resistance required for a resist for producing a liquid crystal display.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been made as a result of intensive studies by the present inventors. It is an object of the present invention to provide a high sensitivity required for a negative resist for manufacturing a liquid crystal display. Another object of the present invention is to provide a negative radiation-sensitive resin composition having high heat resistance and giving an excellent pattern shape.

[0005]

In order to achieve the above object, a negative radiation-sensitive resin composition of the present invention comprises an alkali-soluble resin, a radiation-sensitive acid generator, a methoxymethylated amino resin, an organic amine In the negative-type radiation-sensitive resin composition containing the compound, the alkali-soluble resin,
A phenolic novolak resin obtained from a phenolic compound containing at least 75% by weight of m-cresol, and phenolic compounds (I), (II) and (III) represented by the general formulas (6), (7) and (8) And at least one phenolic compound selected from the group consisting of a triazine compound (I)
V), wherein the methoxymethylated amino resin is at least one of a methoxymethylated melamine resin and a methoxymethylated urea resin, and the organic amine compound is an organic amine compound (V) represented by the general formula (10):
The organic amine compound is added to the radiation-sensitive acid generator in an amount of 1.5 to
It is contained in a range of 10% by weight.

[0006]

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[0007]

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[0008]

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[0009]

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[0010]

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The phenol novolak resin constituting the alkali-soluble resin component includes a reaction product of a phenol and an aldehyde. Examples of phenols include phenol, o-, m- or p-cresol, 2,5-xylenol, 3,6-xylenol, 3,4-xylenol, 2,3,5-trimethylphenol, 4-t-butylphenol, 2-t-butylphenol, 3-t-
Butylphenol, 2-ethylphenol, 3-ethylphenol, 4-ethylphenol, 3-methyl-6
Examples include aromatic compounds such as t-butylphenol, 4-methyl-2-t-butylphenol, 2-naphthol, 1,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, and 1,7-dihydroxynaphthalene. Aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylaldehyde, salicylaldehyde and the like. The reaction between phenols and aldehydes is carried out in the presence of a catalyst, and is carried out in bulk or in a solvent. Organic acids (formic acid, oxalic acid,
p-toluenesulfonic acid, trichloroacetic acid, etc.), inorganic acids (phosphoric acid, hydrochloric acid, sulfuric acid, perchloric acid, etc.), and divalent metal salts (zinc acetate, magnesium acetate, etc.).

The phenol novolak resin used in the present invention has a m-cresol content of 75% by weight or more and 100% or more.
It is a phenol novolak resin obtained from a phenolic mixture in an amount of not more than% by weight, and the above-mentioned phenols can be used as the balance. The content of m-cresol in the phenolic mixture is 75% by weight or more and 1% or more.
00% by weight or less, more preferably 80% by weight or more and 100%
% By weight, most preferably 85% by weight or more and 100% by weight or less. When a phenol novolak resin obtained from a phenolic compound having a content of m-cresol of less than 75% by weight is used, heat resistance is lowered, which is not preferable. The phenolic compound (ballast) generally includes a phenolic low-molecular compound having 2 to 6 benzene rings. Necessary requirements for a phenolic compound that can be suitably used include (1) increasing the dissolution rate of an alkali-soluble resin by addition, (2)
Not exhibiting sublimability at the baking temperature (180 ° C. or lower, normal pressure) of the resist film. Representative examples of the compound satisfying the above requirements are the compounds represented by the general formulas 6, 7 and 8, and in particular, a radiation-sensitive resin composition having excellent resolution by using the compound of the formula 8 Can be obtained. The composition of the present invention may contain other phenolic compounds as long as the resolution is not impaired, in addition to the compounds of Chemical formulas 6 to 8 as phenolic compounds. The amount of such a phenolic low-molecular compound to be added is generally 2% by weight to 40% by weight, preferably 2% by weight to 30% by weight, and most preferably 3% by weight to 20% by weight in the alkali-soluble resin component. % Or less. When the addition amount is less than 2% by weight, the dissolution rate of the unexposed portion in the alkali developing solution decreases, and the resolution deteriorates.
On the other hand, if it exceeds 40% by weight, the dissolution rate of the entire resist film becomes too high to form a good pattern.

The triazine compound as an acid generator includes a triazine compound represented by the general formula (I)
V), specifically, 2- (4-methoxyphenyl) -ethenyl-4,6-bistrichloromethyltriazine,
(2-methoxyphenyl) -ethenyl-4,6-bistrichloromethyltriazine, 2- (4-pentyloxyphenyl) -ethenyl-4,6-bistrichloromethyltriazine, 2- (4-butyloxyphenyl) -ethenyl -4,6-bistrichloromethyltriazine and the like. Other than the above triazine compounds, 2- (3
-Chloro-4-methoxyphenyl) -ethenyl-4,6
-Bistrichloromethyltriazine, 2- (2,5-dimethoxyphenyl) ethenyl-4,6-bistrichloromethyltriazine, 2- (3,4-dimethoxyphenyl) ethenyl-4,6-bistrichloromethyltriazine and the like A bistrichloromethyltriazine compound may be contained. The content of the acid generator is 1 part by weight or more and 6 parts by weight or less, more preferably 1 part by weight or more and 4.5 parts by weight or less, and most preferably 1.5 parts by weight or more based on 100 parts by weight of the alkali-soluble resin. , 4 parts by weight or less. If the addition amount is less than 1 part by weight, the sensitivity and the residual film ratio of the exposed portion decrease, which is not preferable. If the addition amount exceeds 6 parts by weight, the dissolution rate of the unexposed portion decreases, and high resolution is obtained. I can't.

Examples of the methoxymethylated amino resin as the crosslinking agent include methoxymethylated melamine resin, methoxymethylated urea resin, methoxymethylated glycoluril resin, and methoxymethylated ethyleneurea resin. Commercially available resins include Nikarac MW30 manufactured by Sanwa Chemical Co., Ltd.
LM, MW100LM, MX-750, MX-290,
MX-280, N-2702, etc., Mitsui Cytec P
L-1174, CYMEL300 and the like. Particularly preferred in the present invention is a methoxymethylated melamine resin, which may contain another methoxymethylated amino resin as long as the resolution is not impaired. The amount of the crosslinking agent to be added is preferably from 7 to 20 parts by weight, more preferably from 10 to 15 parts by weight, and most preferably from 10 to 13 parts by weight, per 100 parts by weight of the alkali-soluble resin. Part or less. If the addition amount is less than 7 parts by weight, sufficient cross-linking cannot be obtained in the exposed portion, resulting in a decrease in the residual film ratio and deterioration of the shape. When the addition amount exceeds 20 parts by weight, the dissolution rate of the exposed portion Is undesirably increased due to the deterioration of the shape and the decrease in sensitivity.

The amine compound in the present invention is a compound added for the purpose of improving the heat resistance of a resist pattern after development and suppressing the occurrence of a swelling phenomenon due to an aqueous alkaline developer. Examples of such an organic amine compound include a nitrogen-containing amine compound. Specifically, trimethylamine, triethylamine, tri-n-
Propylamine, tri-n-butylamine, tri-n-
Octylamine, tri-n-dodecylamine, tribenzylamine, dicyclohexylmethylamine, 2-phenylpyridine, 3-phenylpyridine, 4-phenylpyridine, piperidine, pyrrolidine, nicotinamide,
Examples thereof include imidazole, 4-methylimidazole, N, N'-dimethylaniline and the like. Preferred amine compound in the present invention, trialkylamine can be cited of the general formalized 10, more preferably the amine, R in the general formalized 10 C ₄ ~
Trialkylamine C _12, specifically, for example, can be exemplified tri -n- butylamine, tri -n- octyl amine. These trialkylamines can be used alone or in combination of two or more. By using these amines, excellent storage stability,
A resist composition having high resolution and high heat resistance can be obtained. When an amine other than a trialkylamine is used, storage stability and resolution are reduced, and furthermore, it cannot be suitably used as an industrial material in terms of harm to the human body. As the addition amount of the amine compound,
Usually, 1.5% by weight or more and 10.0% by weight or less, preferably 1.5% by weight or more and 6.0% by weight or more, more preferably 1.8% by weight or more based on the amount of the acid generator added to the resist. It is at most 5.0% by weight, most preferably at least 1.8% by weight and at most 4.0% by weight. When the addition amount is less than 1.5% by weight, the shape is deteriorated and high resolution cannot be obtained. On the other hand, if it exceeds 10.0% by weight, the sensitivity is remarkably lowered, and it cannot be suitably used for liquid crystal production. In the composition of the present invention, if necessary, a compatible additive, for example, a resin for improving the performance of a resist film, a plasticizer,
Commonly used components such as a stabilizer, a surfactant, a dye for improving the visibility of the resist pattern after development, and a sensitizer for improving the sensitizing effect can also be added.

The above composition is dissolved in a solvent to prepare a negative photoresist composition. Examples of the solvent include ketones such as 2-heptanone, cyclohexanone, methyl butyl ketone, methyl ethyl ketone, 1,1,1-trimethyl acetone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate. Propylene glycols such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl 2-hydroxypropionate (methyl lactate), ethyl 2-hydroxypropionate (ethyl lactate), 2-hydroxypropionic acid 2-hydroxypropionic esters such as propyl, and aliphatic carboxylic acids such as ethyl acetate, propyl acetate and butyl acetate Esters, such as γ- butyrolactone and the like.
These solvents may be used alone or in combination of two or more.

[0017]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention. Examples 1 to 16, Comparative Examples 1 to 8 Mix and dissolve the alkali-soluble resin, the radiation-sensitive acid generator, the methoxymethylated amino resin, the trialkylamine as a basic compound, and the solvent shown in Table 1. .2μ
Foreign matter was removed by microfiltration with an m filter to obtain a resist composition solution. The solution of the obtained resist composition was spin-coated on a 5-inch glass wafer (1.1 mm thick), and baked at 110 ° C. for 90 seconds to form a resist film. A g-line (436 nm) irradiator NSR made by Canon on a 1.0 µm thick resist coating
Radiation was irradiated through a pattern mask by 1505G4C (numerical aperture: 0.42), and baking was performed at 130 ° C. for 90 seconds after irradiation. Then, the film was developed by a paddle method for 60 seconds using a developer consisting of a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH).
After rinsing with deionized water for 20 seconds, it was dried to form a resist pattern. Table 1 shows the obtained results.
The amount of the basic compound added is% by weight based on the acid generator.

[0018]

[Table 1]

The components and solvents shown in Table 1 are as follows. (1) Cresol component composition (% by weight) in novolak resin (A1): m-cresol / p-cresol = 100 /
0 (A2): m-cresol / p-cresol = 80/2
0 (A3): m-cresol / p-cresol = 50/5
0 (2) Phenolic compound (B1): compound (I) represented by general formula (6) (B2): compound (II) represented by general formula (B3): compound represented by general formula (8) III) (3) Radiation-sensitive acid generator (C1): compound represented by general formula (C2): compound represented by general formula (C3): compound represented by general formula (13)

[0020]

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[0021]

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[0022]

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(4) Methoxymethylated amino resin (D1): Methoxymethylated melamine resin (D2): Methoxymethylated urea resin (5) Organic amine compound (E1): Tri-n-butylamine (E2): Tri- n-hexylamine (E3): tri-n-octylamine (E4): tri-n-propylamine (E5): nicotinamide (6) Solvent (F1): 2-heptanone (F2): 2-hydroxypropion Ethyl acid (F3): Propylene glycol monomethyl ether acetate

(7) Optimal exposure: g-line (4
(36 nm) Irradiation was performed through a pattern mask by an irradiation apparatus NSR1505G4C, and baking was performed at 130 ° C. for 90 seconds after irradiation. Then 2.38% by weight
Of tetramethylammonium hydroxide (TMAH)
After developing with a developing solution composed of an aqueous solution, rinsing with deionized water, and drying, a resist pattern was formed. At this time, the 0.5 μ line and space pattern (1L1
The amount of radiation that can form a pattern as designed in S) was determined as the optimum exposure. The unit is mJ / cm ² . The optimum exposure was determined based on the following criteria. Exposure amount of 25 mJ / cm ² or less: exposure amount most preferably used for liquid crystal production Exposure amount exceeds 25 and 35 mJ / cm ² or less: exposure amount suitably used for liquid crystal production Exposure amount of 35 mJ / cm ² Exceeds: Low sensitivity for liquid crystal production and cannot be used. (8) Resolution: The size of the minimum resist pattern that was resolved when irradiating with the optimal exposure was measured and defined as the resolution. (9) Taper angle: The substrate having the developed resist pattern was cut, and the angle formed between the substrate and the inside of the side of the resist pattern was measured with an electron microscope, and the angle was determined as the taper angle. A taper angle in the range of 80 to 90 degrees is best,
Others were considered bad. (10) Heat resistance: 5 μm line and space pattern (1L1S) at optimal exposure dose formed on substrate
After development, baking was performed at 250 ° C. for 120 seconds, the substrate was cut, the cross section was observed with an electron microscope, and compared with the cross-sectional shape of the non-baked resist pattern, which was judged according to the following criteria. ：: The taper angle does not change, and the line width does not change. Δ: The taper angle has changed, and is in a defective range, but the line width does not change. X: The taper angle has changed, it is in a defective range, and the line width has changed.

[0025]

As described above, the present invention has the following effects. (1) Contains a radiation-sensitive acid generator with high sensitivity to light, has high sensitivity and high heat resistance required for negative resists for manufacturing liquid crystal displays and the like, and has excellent high resolution. A pattern shape can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 61/10 C08L 61/10 61/32 61/32 G03F 7/032 G03F 7/032 H01L 21/027 H01L 21/30 502R (72) Inventor Kei Kitano 236 Nakai, Tatsuno-cho, Tatsuno-shi, Hyogo Nagase Electronics Chemical Co., Ltd. F-term (reference) 2H025 AA01 AA02 AA10 AA14 AB14 AB20 AC01 AD01 BE08 BE10 CB17 CB29 CB41 CB42 CC17 CC20 FA12 4J002 CC031 CC041 CC051 CC222 EJ016 EJ036 EJ046 EN028 EN068 EP018 EU028 EU048 EU078 EU118 EU187 FD FD

Claims (1)

[Claims] 1. A negative-type radiation-sensitive resin composition comprising an alkali-soluble resin, a radiation-sensitive acid generator, a methoxymethylated amino resin, and an organic amine compound, wherein the alkali-soluble resin comprises 75% by weight of m-cresol. % Or more of a phenolic novolak resin obtained from a phenolic compound containing at least one selected from phenolic compounds (I), (II) and (III) represented by formulas (1), (2) and (3). Wherein the radiation-sensitive acid generator is a triazine compound (IV) represented by the general formula (4), wherein the methoxymethylated amino resin is a methoxymethylated melamine resin and a methoxymethylated urea resin. Wherein the organic amine compound is an organic amine compound (V) represented by general formula 5, A negative radiation-sensitive resin composition comprising an amine compound in an amount of 1.5 to 10% by weight based on the radiation-sensitive acid generator. Embedded image Embedded image Embedded image Embedded image Embedded image