JP2002287341A - Resist composition and its utilization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition excellent in storage stability and giving a pattern of an inverted taper shape. SOLUTION: The resist composition contains an alkali-soluble resin, a compound which generates an acid when irradiated with active light, a crosslinker and a solvent, and a compound having the maximum absorbance at 300-450 nm wavelength (λ max), having a molar extinction coefficient (ε) of >=25,000 and satisfying the relation of ε>=((400×λmax)-120,000) is used as the compound which generates an acid when irradiated with active light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resist composition and its use.

[0002]

2. Description of the Related Art Organic electroluminescence (hereinafter, referred to as organic electroluminescence)
In the manufacture of display panels (called organic EL),
(1) A pattern on a plurality of stripes made of indium tin oxide (ITO) is formed on a transparent substrate to form a primary display electrode (anode), and (2) a negative resist composition is formed on the entire surface of the substrate from above. Apply a material to form a resist film,
(3) Exposure is performed through a striped photomask perpendicular to the ITO striped pattern. (4) After exposure, baking and development are performed to form a striped negative resist pattern. Organic EL materials (hole transporting material and electron transporting material) are sequentially deposited on the substrate,
(6) A method of manufacturing an organic EL display panel by further depositing a metal such as aluminum thereon has been proposed (JP-A-8-315981).

In this organic EL display panel, the negative resist pattern functions as an electrically insulating partition. If the cross section of the negative resist pattern is a reverse tapered shape (overhang shape), the substrate and the deposited film are independent even if the organic EL material is deposited, and the second display electrode (cathode) is formed thereon. Even if metal is deposited, the second display electrodes are separated from each other by the negative resist pattern, and thus are electrically insulated.

Japanese Patent Application Laid-Open No. Hei 5-16521 discloses a negative resist composition which provides such a reverse tapered pattern.
No. 8, (A) a component capable of crosslinking by exposure to light or exposure and subsequent heat treatment (such as a combination of a component capable of generating an acid upon irradiation with active light and a crosslinking agent), (B) an alkali-soluble resin, And (C) a resist composition containing at least one compound that absorbs light for exposure is known. However, the presence of the compound (C) that absorbs light for exposure tends to lower the sensitivity, and it has been desired to reduce the amount of this component as much as possible. Further, in developing a new resist composition, much effort was required to select a compound that absorbs light for exposure and does not cause a decrease in sensitivity.

[0005]

Under such prior art, the inventors have developed an alkali-soluble resin, a compound capable of generating an acid upon irradiation with actinic rays (hereinafter sometimes referred to as PAG), a crosslinking agent and a solvent. It has been found that when a specific PAG is used in a resist composition containing the compound, it functions instead of the compound absorbing the light beam to be exposed, and a reverse tapered pattern can be easily obtained. But,
The present inventors have confirmed that, instead of reducing the amount of the compound that absorbs light for exposure, increasing the amount of PAG causes PAG to precipitate during storage of the resist composition. Therefore, the present inventors have further studied and found that a compound capable of generating an acid upon irradiation with actinic light has a wavelength λm exhibiting a maximum absorbance.
It was found that when ax and the molar extinction coefficient ε had a specific relationship, PAG was not precipitated and storage stability was excellent, and the present invention was completed.

[0006]

Thus, according to the present invention, there is provided a resist composition comprising an alkali-soluble resin, a compound capable of generating an acid upon irradiation with actinic rays, a crosslinking agent and a solvent, wherein the resist composition comprises As a compound that generates an acid, the wavelength (λmax) showing the maximum absorbance is 300 to
450 nm, molar extinction coefficient (ε) is 25,000 or more, and ε ≧ ((400 × λmax) -12000
0) A resist composition characterized by using a compound having the relationship of 0) is provided, and a step of applying the resist composition to a substrate, drying the resist composition to form a resist film, and exposing light to 365 is performed.
a method of forming a reverse-tapered pattern having a step of irradiating light having a wavelength of nm to 436 nm and a step of developing with a developer. Further, the resist composition is applied to a substrate, dried, and the resist film is formed. Forming, irradiating light with a wavelength of 365 nm to 436 nm,
There is provided a method for forming a luminous body vapor-deposited film including a step of developing and developing with a developer to form a reverse tapered pattern and a step of vapor-depositing a luminous body.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. <Alkali-Soluble Phenolic Resin> In the present invention, the alkali-soluble resins can be used alone or in combination of two or more. Specific examples of the alkali-soluble resin include, for example, a condensation reaction product of a phenol and an aldehyde, a condensation reaction product of a phenol and a ketone, a vinylphenol-based polymer, an isopropenylphenol-based polymer, An alkali-soluble phenol resin such as a hydrogenation reaction product of a phenol resin is suitably used.

Specific examples of the phenols used here include phenol, ortho-cresol, meta-cresol,
Paracresol, 2,3-dimethylphenol, 2,5
-Dimethylphenol, 3,4-dimethylphenol,
3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2-t-butylphenol, 3-t-butylphenol , 4-t-butylphenol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 4-t-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, -Propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol, thymol, isothymol and the like are exemplified. Of these, ortho-cresol, meta-cresol, para-cresol, 2,3-dimethylphenol,
Preferred examples include 3,4-dimethylphenol, 3,5-dimethylphenol, 2,5-dimethylphenol, 2,3,5-trimethylphenol, and 2,3,6-trimethylphenol. These can be used alone or in combination of two or more.

Specific examples of aldehydes include formalin, paraformaldehyde, trioxane, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde,
p-hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde,
Examples thereof include o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, and terephthalaldehyde. Of these, formalin, paraformaldehyde and hydroxybenzaldehydes are preferred. These compounds may be used alone or in combination of two or more.

Specific examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone and the like. These compounds may be used alone or in combination of two or more. These condensation reaction products can be obtained by a conventional method, for example, by reacting a phenol with an aldehyde or a ketone in the presence of an acidic catalyst.

The vinylphenol-based polymer is selected from a homopolymer of vinylphenol and a copolymer with a component copolymerizable with vinylphenol, and the isopropenylphenol-based polymer is a copolymer of isopropenylphenol. It is a homopolymer or a copolymer of isopropenylphenol with a copolymerizable component. Specific examples of components copolymerizable with vinyl phenol and isopropenyl phenol include acrylic acid, methacrylic acid, styrene,
Examples thereof include maleic anhydride, maleic imide, vinyl acetate, acrylonitrile, and derivatives thereof. The copolymer is obtained by a well-known method. The hydrogenation reaction product of the phenolic resin is obtained by a conventional method, for example, by dissolving the phenolic resin in an organic solvent and performing hydrogenation in the presence of a homogeneous or heterogeneous catalyst.

Among the above, particularly preferably, a combination of meta-cresol and para-cresol and the use of a novolak resin obtained by subjecting these to formaldehyde, formalin, or paraformaldehyde to be condensed are expected to improve the sensitivity controllability of the resist. Furthermore, when using meta-cresol and para-cresol in combination, the charged weight ratio during the synthesis of both resins is 3/7 to 7/3, preferably 4/6 to 6/4, and more preferably 4/6 to 5/5. Is good. The weight average molecular weight of the alkali-soluble phenol resin in terms of monodisperse polystyrene (hereinafter simply referred to as average molecular weight) is usually 1,
000 to 5,000, preferably 2,000 to 3,50
0. If the average molecular weight is too low, even if a cross-linking reaction of the exposed part occurs, the molecular weight does not increase, so that it is easily dissolved during the development time, and if it is too high, the unexposed part is easily dissolved during the development time, and in any case, good It is difficult to form a pattern.

As a method for controlling the molecular weight and the molecular weight distribution, a resin is crushed and solidified with an organic solvent having an appropriate solubility.
Examples of the method include liquid extraction, dissolving the resin in a good solvent and dropping it in a poor solvent, or solid-liquid or liquid-liquid extraction by dropping a poor solvent.

<Compound that Generates Acid by Irradiation with Actinic Ray> The resist composition of the present invention contains the above-described alkali-soluble resin and PAG. The PAG used herein is a substance that generates a Bronsted acid or a Lewis acid when exposed to activating radiation, and has the following relationship. That is, the wavelength showing the maximum absorbance (λ
max) is 300 to 450 nm, the molar extinction coefficient (ε) is 25,000 or more, preferably 30,000 or more, and ε ≧ ((400 × λmax) -12000).
0), preferably ε ≧ ((460 × λmax) −140
000).

Among such compounds, a preferred example is biphenyl-s-triazine (λmax = 332n).
m, ε = 32400), 2- (2- (3-chloro-4-)
(Methoxyphenyl) ethenyl) -4,6-bis (trichloromethyl) -s-triazine (λmax = 370n
m, ε = 33000), 2- (4- (2-hydroxyethyloxy) phenethyl) -4,6-bis (trichloromethyl) -s-triazine (λmax = 377 nm, ε
= 37300) and other compounds having a triazine structure. In particular, 2- (2- (3-chloro-4-methoxyphenyl) ethenyl) -4,6-bis (trichloromethyl) -s-triazine or 2- (4- (2-hydroxyethyloxy) phenethyl) -4, A conjugated triazine compound having a triazine structure such as 6-bis (trichloromethyl) -s-triazine, an ethenyl structure represented by -C = C-, and an aromatic ring structure has an exposure wavelength of 36.
Since λmax is in the range of 5 nm to 436 nm, an acid can be efficiently generated even in a small amount, which is preferable in that storage stability is excellent.

In the present invention, the molar extinction coefficient (ε) is
It is a value (ε = absorbance ÷ concentration × molecular weight) calculated using the absorbance measured for a 1.25 × 10 ⁻² mg / ml ethanol solution.

The amount of the PAG to be added is 1 to 10 parts by weight, preferably 3 to 8 parts by weight, based on 100 parts of the alkali-soluble resin. If the amount of PAG used is outside the above range, storage stability tends to be poor.

<Crosslinking Agent> As the crosslinking agent, a compound capable of crosslinking an alkali-soluble resin in the presence of an acid, for example, an acid generated from PAG by exposure is used. Examples of such a crosslinking agent include alkoxymethylated urea resins,
Well-known crosslinkable compounds such as alkoxymethylated amino resins such as alkoxymethylated melamine resins, alkoxymethylated urone resins, and alkoxymethylated glycoluril resins can be mentioned. Examples of suitable alkoxymethylated amino resins include methoxymethylated amino resins, ethoxymethylated amino resins, n-propoxymethylated amino resins, n-butoxymethylated amino resins, and the like. Methoxymethylated urea resin. In the present invention, when a methoxymethylated urea resin is used as a crosslinking agent, a negative radiation-sensitive resin composition having particularly excellent resolution can be obtained.

Suitable commercially available alkoxymethylated amino resins include PL-1170 and PL-117.
4, UFR65, CYMEL300, CYMEL303
(Manufactured by Mitsui Cytec), BX-4000, Nikarac MW-30, MX290 (manufactured by Sanwa Chemical Co., Ltd.) and the like. These crosslinking agents can be used alone or in combination of two or more. The compounding amount of the crosslinking agent in the present invention is as follows.
The amount is usually 3 to 60 parts by weight, preferably 5 to 40 parts by weight, more preferably 5 to 30 parts by weight, per 100 parts by weight. In this case, if the blending amount of the crosslinking agent is too small, it becomes difficult to proceed the crosslinking reaction sufficiently, and as a resist,
The residual film ratio tends to decrease, the pattern tends to swell, and if the amount of the crosslinking agent is too large, the resolution as a resist tends to decrease.

<Compound Absorbing Light for Exposure> The resist composition of the present invention can provide a good reverse tapered pattern even when no compound for absorbing light for exposure is present. It is also possible to use a compound that absorbs light for exposure. Compounds that absorb the light beam to be exposed are described in JP-A-3-25446.
And the cyanovinylstyrene-based compound described in JP-A-63-286843 and 1-cyano-2- (4
-Dialkylaminophenyl) ethylenes and JP-A-58
P- (halogen-substituted phenylazo) -dialkylaminobenzenes described in JP-A-174941;
1-alkoxy-4- (4′-) described in US Pat.
N, N-dialkylaminophenylazo) benzenes,
JP-A-54-95688 describes dialkylamino compounds, nitrile compounds, 1,2-dicyanoethylene, 9-
Others such as cyanoanthracene, 9-anthrylmethylenemalononitrile, N-ethyl-3-carbazolylmethylenemalononitrile, 2- (3,3-dicyano-2-propenylidene) -3-methyl-1,3-thiazoline Oil yellow, oil pink, oil green, oil blue, oil black (all manufactured by Orient Chemical Industries, Ltd.), crystal violet, methyl violet, rhodamine B, malachite green, methylene blue, etc., which are commercially available as common dyes. be able to. The amount of the compound that absorbs light for exposure is 5 parts by weight or less, preferably 1 part by weight or less, more preferably 0.5 part by weight or less, based on 100 parts by weight of the alkali-soluble resin.

<Additives> The resist composition of the present invention comprises:
A general additive for a resist composition such as a surfactant for preventing striation can be included. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and polyoxyethylene oleyl ether; and polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenol ether. Oxyethylene aryl ethers; polyethylene glycol dialkyl esters such as polyethylene glycol dilaurate and ethylene glycol distearate; F-Top EF301, EF30
3, EF352 (manufactured by Shin-Akita Kasei), Megafax F
171, F172, F173, F177 (manufactured by Dainippon Ink), Florado FC430, FC431 (manufactured by Sumitomo 3M), Asahigard AG710, Surflon S-382, SC-101, SC-102, SC-1
03, SC-104, SC-105, SC-106 (manufactured by Asahi Glass Co., Ltd.), etc .; organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); acrylic acid or methacrylic acid (co) polymer polyflow N
o. 75, no. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK). The amount of these surfactants is usually 2 parts by weight or less, preferably 1 part by weight or less, per 100 parts by weight of the solid content of the composition.

In addition to these, the resist composition of the present invention may contain, if necessary, compatible additives such as a storage stabilizer, a sensitizer, and a plasticizer. These can be used instead of those added to a general resist composition for semiconductor production.

<Organic Solvent> The solvent used in the resist composition of the present invention is not particularly limited as long as it can dissolve the above-mentioned components. Specific examples of such a solvent include ketones such as acetone, methyl ethyl ketone, cyclopentanone and cyclohexanone; n-propyl alcohol;
Alcohols such as isopropyl alcohol, n-butyl alcohol and cyclohexanol; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether and dioxane; alcohol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; propyl formate;
Esters such as butyl formate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl lactate, and ethyl lactate; cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate Cellosolve acetates such as;

Propylene glycols such as propylene glycol, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and propylene glycol monobutyl ether; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; trichloroethylene Halogenated hydrocarbons; aromatic hydrocarbons such as toluene and xylene; and polar solvents such as dimethylacetamide, dimethylformamide, and N-methylacetamide. These may be used alone or in combination of two or more.

<Formation of a reverse tapered pattern and formation of a luminous body vapor-deposited film> The resist composition of the present invention is applied to a substrate.
Drying and forming a resist film, light is emitted from 365 nm
A luminous body vapor-deposited film can be formed through a step of irradiating light with a wavelength of 436 nm, a step of developing and developing with a developer to form a reverse tapered pattern, and a step of vapor-depositing a luminous body.

The substrate used in the present invention is not particularly limited, but when an organic EL device is formed, a so-called ITO substrate is generally used. The method for drying the resist film is not particularly limited, and examples thereof include a method of directly heating from the bottom of the substrate using a hot plate and a method of heating the entire substrate from the surroundings using an oven.

After the resist composition of the present invention is applied on a substrate and the solvent is removed, an exposure source used for pattern formation to obtain a desired insulating film includes ultraviolet light, far ultraviolet light, KrF excimer laser light, X-rays, electron beams and the like can be mentioned. As a method of applying the resist composition to the substrate, spin coating is particularly recommended.

After the exposure, the film is developed with an alkali developing solution. An aqueous alkali solution is generally used as the developer, and specific examples thereof include an aqueous solution of an inorganic alkali such as sodium hydroxide, potassium hydroxide, sodium silicate, and ammonia; an aqueous solution of a primary amine such as ethylamine and propylamine; Aqueous solutions of secondary amines such as diethylamine and dipropylamine; aqueous solutions of tertiary amines such as trimethylamine and triethylamine; aqueous solutions of alcoholamines such as diethylethanolamine and triethanolamine; tetramethylammonium hydroxide, tetraethylammonium hydroxide; Quaternary ammonium hydrochloride such as trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide Such as an aqueous solution of Sid and the like. If necessary, a water-soluble organic solvent such as methanol, ethanol, propanol, or ethylene glycol, a surfactant, a resin dissolution inhibitor, or the like can be added to the aqueous alkali solution. Further, in the present invention, it is possible to improve the heat resistance by irradiating ultraviolet rays to cure the film after the exposure and before the luminous body deposition. At this time, the irradiation dose of the ultraviolet irradiation is 5 to 1000 m.
W, preferably 5 to 800 mW.

A luminous body is deposited on the insulating film obtained by the above method. In this step, the luminous body may be deposited on the insulating film in some cases. Although the light emitter is not required on the insulating film, its removal is not essential. The method of vapor deposition is not particularly limited, but is evacuated to about 10 ⁻⁶ Torr,
A general method is to heat the luminous body while rotating the substrate to deposit it on the substrate. The luminous body used in the present invention is an organic EL compound such as Arq (tris (8-quinolinolate) aluminum (III)) or NPD ((N,
N'-dinaphthalen-1-yl) -N, N'-diphenyl-benzidine).

[0030]

The present invention will be more specifically described below with reference to synthesis examples and working examples. The parts and percentages in each example are based on weight unless otherwise specified.

Examples 1-3 and Comparative Examples 1 and 2 420 parts of m-cresol, 280 parts of p-cresol and 350 parts of 37% formalin were obtained by dehydration condensation in the presence of oxalic acid dihydrate. 100 parts of a novolak resin having a weight average molecular weight of about 3200, and a compound described in Table 1 as an acid generator (the amount shown in Table 1 was used).
3.0 parts of "Cymel 303" (trade name, manufactured by Mitsui Cytec Co., Ltd., hexamethylmethoxymelamine) as a crosslinking agent, and a silicon-based surfactant "KP-341"
After dissolving 0.1 part (trade name, manufactured by Shin-Etsu Silicone Co., Ltd.) in 180 parts of propylene glycol monoethyl acetate, the solution was filtered through a 0.1 μm polytetrafluoroethylene filter to prepare a resist composition. The number of fine particles having a particle size of 0.25 μm or more in 1 ml of the resist composition was measured using a liquid particle counter KL-20 (manufactured by Rion).場合 when the number of fine particles is less than 30; ○ when the number is 30 or more and less than 50;
00 or more were evaluated as x. Table 1 shows the results. After storing these resist compositions at −5 ° C. for 3 months, the number of fine particles having a particle size of 0.25 μm or more was measured in the same manner. Table 1 shows the results.

The resist composition after the storage test was applied on an ITO substrate using a coater, and prebaked at 90 ° C. for 90 seconds to form a resist film having a thickness of 4.0 μm. This wafer is placed in a parallel light aligner (PL
A501F (manufactured by Canon Inc.) After exposure for 2 minutes at about 200 mJ / cm ³ using a test reticle,
Post exposure bake (Post Expos) at 10 ° C. for 60 seconds
ure Banking). Next, 23.38% aqueous solution of tetramethylammonium hydroxide is used.
The pattern was formed by developing by paddle method at 1 ° C. for 1 minute. The cross section of the obtained pattern was confirmed by a scanning electron microscope (“JSM-5400” manufactured by JEOL Ltd.). Table 1 shows the results.

[0033]

[Table 1]

[0034]

The wavelength (λ) showing the maximum absorbance as PAG
max) is 300 to 450 nm, the molar extinction coefficient (ε) is 25,000 or more, and ε ≧ ((400 × λma
x) -120,000), a resist composition having excellent storage stability and giving a reverse tapered shape can be obtained.

Continued on the front page F term (reference) 2H025 AA03 AA11 AB20 AC01 AD01 BE08 CB17 CB29 CB42 CC17 FA43 2H096 AA30 BA06 EA02 HA27 KA25 4J002 BC121 BH011 CC031 CC101 CC132 CC182 CK012 EU186 FD020 FD142 FD200 QFD206 FD310 G310

Claims (4)

[Claims] Claims: 1. A resist composition comprising an alkali-soluble resin, a compound capable of generating an acid upon irradiation with actinic light, a crosslinking agent and a solvent, the compound having a maximum absorbance as a compound capable of generating an acid upon irradiation with actinic light. Wavelength (λmax)
Is 300 to 450 nm, and the molar extinction coefficient (ε) is 2500.
0 or more and ε ≧ ((400 × λmax) −1
20,000). A resist composition comprising a compound having a relationship of 20,000). 2. The resist composition according to claim 1, wherein the compound generating an acid upon irradiation with actinic light is a compound having a triazine structure. 3. A step of applying the resist composition according to claim 1 on a substrate, drying the resist composition to form a resist film, irradiating light with a wavelength of 365 nm to 436 nm, and developing with a developer. Forming a reverse-tapered pattern having: 4. A step of applying the resist composition according to claim 1 or 2 on a substrate, drying the resist composition to form a resist film, irradiating light with light having a wavelength of 365 nm to 436 nm, and developing with a developer. A method for forming a luminous body deposited film, comprising the steps of forming a reverse tapered pattern and vapor-depositing a luminous body.