TWI387849B - Radiation sensitive resin composition suitable for spinless, slit coating - Google Patents

Description

Photosensitive resin composition suitable for non-rotating, slit coating

The present invention relates to a photosensitive resin composition for non-rotation and slit coating, and more specifically, when it is applied by a non-rotation or slit coating method, a resin coating film having a uniform film thickness uniformity can be formed. A photosensitive resin composition for rotation and slit.

In the production of semiconductor integrated circuit elements, color filters, liquid crystal display elements, and the like, conventionally, photolithography technology has been used for fine processing, and in recent years, development of sub-micron fine processing technology has been progressing. In such a photolithography technique, after forming an antireflection film on a substrate as necessary, a positive or negative photosensitive resin composition is applied and baked in advance to form a photosensitive photoresist film. Then, the photosensitive resist film is formed by exposing a pattern to various types of radiation such as ultraviolet rays, far ultraviolet rays, electron beam, and X-rays to form a photoresist pattern.

Various methods such as a spin coating method, a roll coating method, a mold clamping method, a cast coating method, a knife coating method, and a dip coating method are known as a method of applying the photosensitive resin composition. Specifically, in the production of a semiconductor integrated circuit element or a liquid crystal display element, a positive photosensitive resin composition is often used as the resin material, and a spin coating method is often used in the coating method. Further, in the production of a liquid crystal display element, a spin coating method and a roll coating method are generally employed as a coating method.

Therefore, in the case of using the spin coating method as a method of coating a photosensitive resin composition on a substrate, the resin solution that has been dropped onto the substrate is borrowed After the centrifugal force is generated in the outer circumferential direction of the substrate due to the centrifugal force generated by the rotation of the substrate, most of the photoresist solution is removed from the outer periphery of the substrate by the excess photoresist solution, and the scattered photoresist solution is discarded. In the spin coating method, as opposed to the fact that a photoresist film having a uniform film thickness can be easily formed, there is a disadvantage that the amount of photoresist which is discarded as described above is large and becomes high in cost. On the other hand, the roll coating method can reduce the cost of the photoresist by using most of the photoresist used, but there is a coating such as a ridge or orange peel when the photosensitive resin composition is applied. The disadvantage of unevenness. For example, in a liquid crystal display device produced by using a photoresist film having uneven coating properties, the lightness of light is generated, and the value of the product tends to be low. Therefore, an improved roll coating method has been proposed (patent Document 1).

Further, in order to increase the size of the substrate in recent years, the slit coating method has become the mainstream instead of the spin coating method. Even in the case of using their coating methods, the composition of the composition is generally the same. For example, a photosensitive resin composition for producing a flat panel display is generally known as a photosensitive resin group containing a phenol resin and a benzoquinone diazide sensitizer as a main component, and a coating film is formed by a slit coating method. In the case, or when it is necessary to adjust the viscosity, most of them are used. However, in the general slit coating method (for example, the coating speed of the photosensitive resin composition is about 100 mm/sec), the tendency of swelling at the end portion of the coated surface is high, and the terminal portion having a thick film thickness is necessary for cutting. , the yield is getting worse. From the viewpoint of productivity, in the high-speed scanning coating which further increases the coating speed (for example, the coating speed of the photosensitive resin composition is about 150 mm/sec), the tendency is stronger, and it is desirable to use no rotation or slit. A sufficiently uniform film thickness is obtained during the coating process A photosensitive resin composition.

[Patent Document 1] JP-A-2000-267270

An object of the present invention is to provide a photosensitive resin composition which is free from the drawbacks which have hitherto been a problem in the non-rotating and slit coating method. Specifically, a photosensitive resin composition which suppresses scattering of a film thickness and has high coating film thickness uniformity when applied by a non-rotation or slit coating method is provided.

The present inventors have found that in the conventional photoresist composition, when coated by a non-rotation or slit coating method, there is a problem in film thickness uniformity at the end surface of the substrate, and an alkali-soluble phenol resin or the like is contained. In the photosensitive resin composition of the sensitizer such as an alkali-soluble resin and a naphthoquinone diazide compound, a photosensitive resin composition having good coating properties is obtained by containing a specific compound which esterifies a fatty acid with an alcohol, and thus the present invention has been completed. In other words, the photosensitive resin composition of the present invention is characterized by comprising an alkali-soluble phenol resin, a sensitizer, and an ester of a fatty acid having 10 to 20 carbon atoms and an alcohol having 1 to 5 carbon atoms.

Further, the method for producing a photoresist substrate according to the present invention is characterized in that the photosensitive resin composition is applied onto a substrate by a slit coating method, and the photoresist substrate of the present invention is also a method of the present invention. Made as a special feature.

By using a photosensitive resin composition suitable for the non-rotation and slit coating method of the present invention, it is possible to form a coating film having a uniform coating film thickness uniformity, and therefore, it is possible to manufacture at low cost in the production of a liquid crystal display device or the like. High-quality products with no light and light.

The photosensitive resin composition in the present invention contains an alkali-soluble phenol resin, a sensitizer, and an ester of a fatty acid and an alcohol as essential components. The components are as described below.

The alkali-soluble phenol resin used in the photosensitive resin composition of the present invention is a phenol resin type phenol resin obtained by condensation polymerization of at least one phenol with aldehydes such as formaldehyde water.

Examples of the phenol used in the production of the alkali-soluble phenol resin include cresols such as o-cresol, p-cresol and m-cresol; 3,5-xylenol, 2,5-xylenol, and 2 , xylenols such as 3-xylenol and 3,4-xylenol; 2,3,4-trimethyl phenol, 2,3,5-trimethyl phenol, 2,4,5-trimethyl phenol, 3, Tricresols such as 4,5-tricresol; tert-butylphenols such as 2-tertiol, 3-tert-butylphenol, 4-tertiol, etc.; 2-methoxyphenol, 3-methyl a methoxy phenol such as oxyphenol, 4-methoxy phenol, 2,3-dimethoxy phenol, 2,5-dimethoxy phenol or 3,5-dimethoxy phenol; Ethylphenol such as acetol, 3-ethylphenol, 4-ethylphenol, 2,3 diethylphenol, 3,5-diethylphenol, 2,3,5-triethylphenol, 3,4,5-triethylphenol Chlorophenols such as o-chlorophenol, m-chlorophenol, p-chlorophenol, 2,3-dichlorophenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, Resorcinol such as 5-methylresorcin; catechols such as 5-methylcatechol; gallic phenols such as 5-methyl galletol; bisphenol A, B, C, Bisphenols such as D, E, and F; methylolated cresols such as 2,6-dimethylol-p-cresol; α-naphthol And naphthols such as β-naphthol. They are used in a mixture of singly or plural kinds.

Further, as the aldehyde, in addition to formaldehyde water, there are linalaldehyde, trioxane, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, chloroacetaldehyde, etc., which are used alone or in combination of plural kinds.

In the case of the alkali-soluble phenol resin used therein, those which remove low molecular weight components, respectively, may also be used. Examples of the method for removing the low molecular weight component, respectively, are a liquid-liquid separation method in which a resin is separated in two kinds of solvents having different solubility, a method of removing a low molecular weight component by centrifugation, a thin film distillation method, or the like.

As the sensitizer, a sensitizer containing a phenylhydrazine diazide group is preferred. As the sensitizer containing a benzoquinonediazide group, any of the well-known sensitizers used in the conventional benzoquinonediazide-phenolic resin can also be used. In terms of sensitizers, by using chlorinated naphthoquinonediazidesulfonic acid or benzoquinonediazidesulfonic acid, etc., with a low molecular compound having a functional group capable of condensing with the acid chloride or A compound obtained by reacting a polymer compound is preferred. The functional group which can be condensed with the acid chloride is exemplified by a hydroxyl group, an amine group and the like, and particularly preferably a hydroxyl group. Examples of the compound containing a hydroxyl group which can be condensed with an acid chloride include hydroquinone; resorcin; 2,4-dihydroxydiphenyl ketone; 2,3,4-trihydroxydiphenyl ketone; 4,6-trihydroxydiphenyl ketone, 2,4,4'-trihydroxydiphenyl ketone, 2,3,4,4'-tetrahydroxydiphenyl ketone, 2,2',4,4' - Hydroxydiphenyl ketones such as tetrahydroxydiphenyl ketone, 2,2',3,4,6'-pentahydroxydiphenyl ketone; bis(2,4-dihydroxyphenyl)methane, bis ( Hydroxyphenyl alkane such as 2,3,4-trihydroxyphenyl)methane or bis(2,4-dihydroxyphenyl)propane; 4,4',3",4"-tetrahydroxy-3,5 , 3',5'-tetramethyltriphenylmethane, 4,4',2",3",4"-pentahydroxy-3,5,3',5'-tetramethyltriphenylmethane, etc. The hydroxytriphenylmethanes, etc. may be used singly or in combination of two or more.

Further, chlorinated naphthoquinonediazidesulfonic acid or chlorinated quinonediazidesulfonic acid As the acid chloride, chlorinated-1,2-naphthoquinonediazide-5-sulfonic acid, chlorinated-1,2-naphthoquinonediazide-4-sulfonic acid, and the like are preferred. The compounding amount of the benzoquinone diazide-based sensitizer is usually from 5 to 50 parts by weight, preferably from 10 to 40 parts by weight, per 100 parts by weight of the alkali-soluble resin. When it is less, it becomes a photosensitive tree composition and it cannot acquire sufficient sensitivity, and when it is many, it must pay attention to the problem which arises by analysis.

The photosensitive resin composition of the present invention is formed by including an ester of a fatty acid and an alcohol. The carboxylic acid in which the fatty acid is a chain hydrocarbon having a carbon number of 10 to 20 and preferably 14 to 18, particularly a monocarboxylic acid or a dicarboxylic acid, may be a saturated fatty acid or an unsaturated fatty acid, and the hydrocarbon may have a branched chain. . Further, it may be substituted with a hydroxyl group, an amine group or the like insofar as it does not impair the effects of the present invention. The alcohol is preferably a lower alcohol having 1 to 5 carbon atoms and preferably 1 to 3, and particularly preferably a monool. The esters used in the photosensitive resin composition of the present invention can be obtained by reacting these fatty acids with an alcohol under the usual esterification reaction conditions.

Specific examples of preferred esters in the photosensitive resin composition of the present invention, for example, saturated fatty acid esters include methyl laurate, ethyl laurate, methyl myristate, and ethyl myristate. , methyl palmitate, ethyl palmitate, methyl stearate, ethyl stearate; unsaturated fatty acid esters are exemplified by methyl oleate, ethyl oleate, methyl ricinoleate, castor oil Ethyl acetate, methyl linoleate, ethyl linoleate, methyl linolenic acid, ethyl linoleic acid and the like. These esters may be used singly or in combination of two or more kinds as necessary.

The amount of the ester added is usually from 1 to 20 parts by weight, preferably from 1 to 10 parts by weight, per 100 parts by weight of the total weight of the phenol resin and the sensitizer. ester When the content of the class is less than that, it is found that the effect of the present invention is insufficient, that is, the uniformity of the thickness of the coating film is impaired, and the sensitivity is lowered as compared with the case where it is large, and it is necessary to pay attention to that sufficient sensitivity cannot be obtained.

The photosensitive resin composition in the present invention may contain a solvent as necessary. The solvent usually contains a solvent which can dissolve the above-mentioned respective components and an additive described later. Examples of the solvent which can be used include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; ethylene glycol monomethyl ether acetate and ethylene glycol; Ethylene glycol monoalkyl ether acetate such as monoethyl ether acetate; propylene glycol monoalkyl ether such as propylene glycol monomethyl ether or propylene glycol monoethyl ether; propylene glycol monomethyl ether acetate, propylene glycol Propylene glycol monoalkyl ether acetates such as monoethyl ether acetate; lactic acid esters such as methyl lactate and ethyl lactate; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone; a ketone such as heptanone or cyclohexanone; a guanamine such as N,N-dimethylacetamide or N-methyltetrahydropyrrolidone; a lactone such as γ-butyrolactone. These solvents may be used singly or in combination of two or more.

The photosensitive resin composition in the present invention may further contain a surfactant as necessary. When the photosensitive resin composition is applied to the substrate, a fish scale-like appearance (hereinafter referred to as "fog") is formed on the surface, but the photosensitive resin composition in the present invention is suppressed by using the interface active agent. The fog spot. In particular, a nonionic surfactant is preferably used in the photosensitive resin composition of the present invention. Examples of the nonionic surfactant include a fluorine-based surfactant, a ruthenium-based surfactant, and a hydrocarbon-based surfactant. Particularly, a fluorine-based surfactant is preferably used. The amount of the surfactant is 1 part by weight relative to the total amount of the alkali-soluble resin and the sensitizer, and is usually added. 200~10000ppm. When the content of the surfactant is too large, attention must be paid to problems such as poor development.

Further, the photosensitive resin composition of the present invention may be formed by further containing a phenolic compound as necessary. By using a phenolic compound in the photosensitive resin composition of the present invention, the effect of improving the sensitivity can be obtained. The phenolic compounds are, for example, those represented by the following formula (1): (wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ^{7 each} independently represent H, C ₁ -C ₄ alkyl or (wherein R ⁸ is H, C ₁ -C ₄ alkyl), m and n are each independently an integer of 0 to 2, and a, b, c, d, e, f, g, and h satisfy a+b ≦5, c+d≦5, e+f≦5, g+h≦5, an integer from 0 to 5, and i is an integer from 0 to 2. )

Specific examples of such phenolic compounds include o-cresol, M-cresol, p-cresol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, bisphenol A, B, C, E, F and G, 4, 4' , 4"-methine trisphenol, 2,6-bis[(2-hydroxy-5-tolyl)methyl]-4-cresol, 4,4'-[1-[4-[1-( 4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol, 4,4'-[1-[4-[2-(4-hydroxyphenyl)-2-propyl Phenyl]ethylidene]bisphenol, 4,4',4"-ethylidenetriol, 4-[bis(4-hydroxyphenyl)methyl]-2-ethoxyphenol, 4,4' -[(2-hydroxyphenyl)methylene]bis[2,3-xylenol], 4,4'-[(3-hydroxyphenyl)methylene]bis[2,6-xylenol ], 4,4'-[(4-hydroxyphenyl)methylene]bis[2,6-xylenol], 2,2'-[(2-hydroxyphenyl)methylene] bis[3] ,5-xylenol], 2,2'-[(4-hydroxyphenyl)methylene]bis[3,5-xylenol], 4,4'-[(3,4-dihydroxybenzene) Methylene] bis[2,3,6-tricresol], 4-[bis(3-cyclohexyl-4-hydroxy-6-methylphenyl)methyl]-1,2-benzenediol, 4 ,6-bis[(3,5-dimethyl-4-hydroxyphenyl)methyl]-1,2,3-benzenetriol, 4,4'-[(2-hydroxyphenyl)methylene ] bis[3-cresol], 4,4',4"-(3-methyl-1-propenyl-3-iriidine)triol, 4,4',4",4'"-( 1,4-phenylene secondary methyl)tetraphenol, 2,4,6-tri [ (3,5-Dimethyl-4-hydroxyphenyl)methyl]-1,3-benzenediol, 2,4,6-tris[(3,5-dimethyl-2-hydroxyphenyl) Methyl]-1,3-benzenediol, 4,4'-[1-[4-[1-[4-hydroxy-3,5-bis[(hydroxy-3-methylphenyl)methyl]phenyl) ]-1-methylethyl]phenyl]ethylidene]bis[2,6-bis(hydroxy-3-methylphenyl)methyl]phenol, etc. Further preferred compounds are 4, 4 ',4"-methine trisphenol, 2,6-bis[(2-hydroxy-5-tolyl)methyl]-4-cresol, 4,4'-[1-[4-[1- (4-Hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol, 4,4'-[1-[4-[2-(4-hydroxyphenyl)-2-propane Phenyl]ethylidene]bisphenol, 4,4',4"-ethylidenetriol, and the like.

Among these phenolic compounds, those of the following formula (Ia) or (Ib) are particularly preferred.

The amount of the phenolic compound to be added is usually 1 to 25 parts by weight, preferably 1 to 20 parts by weight, per 100 parts by weight of the alkali-soluble phenol resin and the sensitizer.

The photosensitive resin composition in the present invention is formed by including the above respective components, but its properties are a solution or a dispersion. The general viscosity is prepared in accordance with the coating conditions for applying the composition. However, the photosensitive resin composition of the present invention preferably has an kinetic viscosity at 25 ° C of 2 to 10 cSt and preferably 2 to 5 cSt. When the dynamic viscosity is outside this range, care must be taken to lose the uniformity of the coating film thickness due to too high or too low.

The present invention will be described below by way of examples.

[Example 1]

Phenolic resin: a phenol resin having a weight average molecular weight of about 10,000 in terms of polystyrene.

Photosensitive agent: average esterification rate is 75%, and 25 parts by weight of 2,3,4,4'-tetrahydroxydiphenyl ketone and 1,2-naphthyl chloride are added with respect to 100 parts by weight of the phenol resin. An ester compound of diazide-5-sulfonic acid.

Active agent: 6000 ppm of a fluorine-based surfactant Mega Fak (manufactured by Dainippon Ink Chemical Co., Ltd.) was added to all the solid components.

After adding 10 parts of methyl stearate to 100 parts by weight of all the solid components of the above composition, the mixture was stirred and dissolved again, and the solid concentration was adjusted to 25 ° C by a Canon Finsk automatic viscometer (manufactured by Clutch Corporation). The dynamic viscosity was 4 cSt to obtain a composition.

[Example 2]

Phenolic resin: a phenol resin having a weight average molecular weight of about 10,000 in terms of polystyrene.

Photosensitive agent: average esterification rate is 75%, and 25 parts by weight of 2,3,4,4'-tetrahydroxydiphenyl ketone and chlorinated-1,2-naphthoquinone are stacked with respect to 100 parts by weight of the phenolic resin. An ester compound of nitrogen-5-sulfonic acid.

Active agent: 6000 ppm of a fluorine-based surfactant, Megaric (manufactured by Dainippon Ink Chemical Co., Ltd.), was added to all the solid components.

After adding 10 parts of ethyl stearate to 100 parts by weight of the total solid content of the above composition, the mixture was stirred and dissolved again, and the solid concentration of the solid component was adjusted to a dynamic viscosity of 5 cSt at 25 ° C by a Canon Finsk automatic viscometer. Composition.

[Comparative Example 1]

Phenolic resin: a phenol resin having a weight average molecular weight of about 10,000 in terms of polystyrene.

Photosensitive agent: average esterification rate is 75%, and 25 parts by weight of 2,3,4,4'-tetrahydroxydiphenyl ketone and 1,2-naphthyl chloride are added with respect to 100 parts by weight of the phenol resin. An ester compound of diazide-5-sulfonic acid.

After dissolving the solid composition in a solvent, the composition was obtained by adjusting the solid content concentration to a dynamic viscosity at 25 ° C of 4 cSt by a Canon Finsk automatic viscometer.

[Comparative Example 2]

Phenolic resin: a phenol resin having a weight average molecular weight of about 10,000 in terms of polystyrene.

Photosensitive agent: average esterification rate is 75%, and 25 parts by weight of 2,3,4,4'-tetrahydroxydiphenyl ketone and chlorinated-1,2-naphthoquinone are stacked with respect to 100 parts by weight of the phenolic resin. An ester compound of nitrogen-5-sulfonic acid.

Active agent: 6000 ppm of a fluorine-based surfactant, Megaric (manufactured by Dainippon Ink Chemical Co., Ltd.), was added to all the solid components.

After dissolving the solid composition in a solvent, the composition was obtained by adjusting the solid content concentration to a dynamic viscosity at 25 ° C of 4 cSt by a Canon Finsk automatic viscometer.

[Example 3]

Phenolic resin: a phenol resin having a weight average molecular weight of about 10,000 in terms of polystyrene.

Photosensitive agent: average esterification rate is 75%, and 25 parts by weight of 2,3,4,4'-tetrahydroxydiphenyl ketone and chlorinated-1,2-naphthoquinone are stacked with respect to 100 parts by weight of the phenolic resin. An ester compound of nitrogen-5-sulfonic acid.

After adding 10 parts of methyl stearate to 100 parts by weight of the total solid content of the above composition, the mixture was stirred and dissolved again, and the solid viscosity was adjusted to a dynamic viscosity of 5 cSt at 25 ° C by a Canon Finsk automatic viscometer. Composition.

[Example 4]

Phenolic resin: a phenol resin having a weight average molecular weight of about 10,000 in terms of polystyrene.

Photosensitive agent: average esterification rate is 75%, and 25 parts by weight of 2,3,4,4'-tetrahydroxydiphenyl ketone and chlorinated-1,2-naphthoquinone are stacked with respect to 100 parts by weight of the phenolic resin. An ester compound of nitrogen-5-sulfonic acid.

Phenolic compound: 5 parts by weight of TrisP-PA (manufactured by Honshu Chemical Industry Co., Ltd.: general formula (Ia)) was added to 100 parts by weight of the phenolic and sensitizing agent.

Active agent: 6000 ppm of a fluorine-based surfactant, Megaric (manufactured by Dainippon Ink Chemical Co., Ltd.), was added to all the solid components.

After adding 10 parts of methyl stearate to 100 parts by weight of the total solid content of the above composition, the mixture was stirred and dissolved again, and the solid viscosity was adjusted to a dynamic viscosity of 5 cSt at 25 ° C by a Canon Finsk automatic viscometer. Composition.

Coating uniformity evaluation

Each of the photosensitive resin compositions was applied onto a glass substrate (substrate size: 1100 × 1250 mm) by a slit coater, dried under reduced pressure, and then prebaked with a hot plate to form a photosensitive resin film having a thickness of about 1.5 μm.

Using an optical film thickness measuring device, 90 points were measured from the left end portion to the right end portion of the substrate in the direction perpendicular to the coating direction, and the average film thickness was calculated except for 50 mm except for the terminal portion of the substrate, except for 20 mm except for 15 mm except for 10 mm. And the maximum value and the minimum value are obtained by the following formula: (maximum value - minimum value) / average film thickness / 2 × 100 In-plane uniformity (%) was obtained. Then, it is estimated that the difference is less than 2%, ◎, 2% or more, less than 3%, ○, 3% or more, less than 4%, Δ, and 4% or more, ×. The results obtained are shown in Table 1.

Evaluation of the properties of the coated surface

Further, the properties of the coating film were evaluated by visual observation under a sodium lamp. A mist spot was observed on the sample-coated surface of Comparative Example 1, and no fogging was observed at all on the sample-coated surfaces of Examples 1, 2, and 4 containing both the ester and the surfactant.

Claims (7)

A photosensitive resin composition for slit coating comprising an alkali-soluble phenol resin, a sensitizer, and an ester of a fatty acid having 10 to 20 carbon atoms and an alcohol having 1 to 5 carbon atoms, and is formed at 25 ° C The dynamic viscosity is 2~10cSt. The photosensitive resin composition for slit coating according to the first aspect of the invention, wherein the sensitizer is a benzoquinonediazide group. The photosensitive resin composition for slit coating according to the first aspect of the invention, further comprising a surfactant. The photosensitive resin composition for slit coating according to the second aspect of the invention, further comprising a surfactant. The photosensitive resin composition for slit coating of any one of Claims 1 to 4 which further contains a phenolic compound. A method for producing a resistive substrate, comprising the step of coating a photosensitive resin composition for slit coating according to any one of claims 1 to 5 on a substrate by a slit coating method. A photoresist substrate characterized by being manufactured by the manufacturing method of claim 6 of the patent application.