KR100585303B1 - Positive photoresist composition for manufacturing substrate provided with integrated circuits and liquid crystal on one substrate and formation method of resist pattern - Google Patents

Abstract

Provided is a positive type photoresist composition (for system LCD) on which an integrated circuit and a liquid crystal display portion are formed on one substrate having good resolution, good DOF characteristics, suitable for i-line exposure, and excellent in linearity and sensitivity do. The positive type photoresist composition for system LCD is a positive type photoresist composition comprising (A) an alkali-soluble resin, (B) a naphthoquinone diazide esterified compound and (C) a phenolic hydroxyl group- As the photoresist composition,

Wherein the component (B) contains an esterification reaction product of a non-benzophenone-based compound containing a phenolic hydroxyl group and a 1,2-naphthoquinone diazidesulfonic acid compound, and the color value of the resist composition is 0.15 or less to be.

A liquid crystal display, a positive type photoresist composition, a resist pattern

Description

TECHNICAL FIELD [0001] The present invention relates to a positive type photoresist composition for forming a substrate on which an integrated circuit and a liquid crystal display portion are formed on a single substrate, and a method of forming a resist pattern using the positive type photoresist composition.

1 is an explanatory view of a positive type photoresist composition applied to a glass substrate for baking, drying and pattern-exposed for linearity evaluation, and then containing developer from a substrate end X to a developing unit with a slit coater.

The present invention relates to a positive type photoresist composition for producing a substrate on which an integrated circuit and a liquid crystal display portion are formed on one substrate and a method of forming a resist pattern.

As a conventional positive photoresist composition for a TFT (LCD), it is preferable to use a novolak resin and a naphthoquinone diazide compound as a photosensitive component (PAC), since they are suitable for ghi ray exposure and are inexpensive and highly sensitive. -Naphthoquinone diazide-based resist compositions have been used (JP-A Nos. 2000-131835, 2001-75272, 2000-181055, 2000-112120). The resist was a resist material for forming a very rough pattern (about 3 to 5 mu m) for forming a pixel portion of a display.

On the other hand, as a next-generation LCD, the development of high-performance LCD technology in which an integrated circuit such as a driver, a DAC (digital-analog converter), an image processor, a video controller, and a RAM are formed on a single substrate, (Semiconductor FPD World 2001.9, pp.50-67). Hereinafter, a substrate on which an integrated circuit and a liquid crystal display portion are formed on one substrate is referred to as a system LCD for convenience.

Recently, a system LCD using low-temperature polysilicon as a substrate has been actively developed, and development of a resist composition suitable for the production of the system LCD has been desired.

As a resist material suitable for the production of such a system LCD, there has been proposed a resist composition which is capable of simultaneously forming a fine pattern and a rough pattern in a good shape (linearity), a high resolution, Much more stringent characteristics than those of LCD manufacture are required.

In addition, in the production of the system LCD, since introduction of i-line (365 nm) exposure is expected in the photolithography process, it is required to be suitable for exposure at that wavelength, that is, a resist material for i-line exposure.

In addition, since the decrease in sensitivity causes a lethal reduction in throughput in the field of liquid crystal device (LCD) production, it is desired that the above characteristics are satisfied and sensitivity deterioration does not occur.

However, until now, there has been no report on a resist material for a system LCD, and it has been strongly desired to realize a resist material suitable for a system LCD in the LCD manufacturing industry.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and provides a positive photoresist composition and a method of forming a resist pattern which are excellent in resolution, DOF characteristics, suitable for i-line exposure, excellent in linearity and sensitivity, And the like.

The present invention solves the above problems by the following means.

The first invention is a positive photoresist composition comprising (A) an alkali-soluble resin, (B) a naphthoquinone diazide esterified compound and (C) a phenolic hydroxyl group-containing compound having a molecular weight of 1000 or less in an organic solvent,

Wherein the component (B) contains an esterification reaction product of a non-benzophenone-based compound containing a phenolic hydroxyl group and a 1,2-naphthoquinone diazidesulfonic acid compound,

Further, the resist composition is a positive type photoresist composition for producing a substrate on which an integrated circuit and a liquid crystal display portion are formed on one substrate, characterized in that the color value of the resist composition is 0.15 or less.

(2) a step of forming a resist film on a substrate by heat treatment (prebaking) the substrate on which the coating film is formed; and (2) a step of forming a resist film on the substrate by heat treatment 3) selectively exposing the resist film to a resist pattern using a mask having both a mask pattern for forming a resist pattern of 2.0 탆 or less and a mask pattern for forming a resist pattern having a size of more than 2.0 탆; (Post exposure bake) the resist film after the heat treatment, (5) the resist film after the heat treatment is subjected to development processing using an aqueous alkali solution, and a resist pattern for an integrated circuit having a pattern size of 2.0 m or less , And a step of simultaneously forming a resist pattern for a liquid crystal display part of more than 2.0 mu m A process for forming a resist pattern according to claim.

BRIEF DESCRIPTION OF THE DRAWINGS Fig.

<Color value>

The color value is a value obtained by the following formula.

Color value = [43.5 / resist concentration (mass%)] x absorbance

The resist concentration in the equation is the solid concentration in the resist composition.

43.5 is a standard value of the solid content concentration of the resist composition.

The absorbance is an absorbance of a resist composition having a wavelength of 500 nm, and is measured as follows.

0.1 ml of the resist composition was diluted with 25 ml of propylene glycol monomethyl ether (PGME), placed in a quartz cell having a thickness of 1 cm as a liquid layer, and measured by a spectrophotometer (for example, spectrophotometer 330 type (manufactured by Hitachi, Ltd.) Was measured.

The solid content is the components (A) to (C) and various additives to be added as needed.

In the present invention, the color value of the resist composition is 0.15 or less, preferably 0.1 or less. The smaller the color value is, the better, and there is no technical significance to limit the lower limit, but it is practically 0.01 or more.

By setting the color value to 0.15 or less, it is possible to obtain a photoresist composition having good resolution and DOF characteristics, being suitable for i-line exposure, excellent in linearity and sensitivity, and suitable for system LCD.

The reason why these characteristics are improved by setting the color value to 0.15 or less is not clear, but it is presumably due to the following reasons.

The color value defined by the above equation is proportional to the value of the absorbance at a wavelength of 500 nm, and an azo bond (-N = N-) can be considered as a chemical bond having absorption at that wavelength.

Since the azo bond is a bond that is not originally present in the resist composition, the present inventors presumed that the azo bond is a heat-decomposition product of the naphthoquinone diazide esterified product as the photosensitive component.

That is, in the resist composition in which the azo bond exists so that the color value exceeds 0.15, deterioration of the photosensitive component naphthoquinone diazide esterified compound is remarkable. Conversely, when the resist composition has a color value of 0.15 or less, It is presumed that the improvement of the resist characteristics is realized by making the color value to be 0.15 or less at the time of the resist preparation.

The generation of azo bonds is also disclosed in Japanese Patent Application Laid-Open No. Hei 10-232491, but there has been no report on how much control is appropriate as a resist composition for system LCD.

The color value can be changed by adjusting the temperature and time of the heat treatment performed when the resist composition is prepared. In the adjustment of the resist composition, there is a case where the heat treatment is carried out from the viewpoint of improving the storage stability, etc., when the solid components such as the components (A) to (C) are dissolved in an organic solvent or after they are dissolved 8-262698 and 6-256565).

When the heat treatment is performed under severe conditions, the color value tends to deteriorate. Therefore, the resist composition of the present invention can be obtained by heating and adjusting the temperature and time at which the color value becomes 0.15 or less.

The color value can be adjusted by using a photosensitive component that does not increase absorption of light having a wavelength of 500 nm over time. Further, it can be adjusted by reducing the blending amount of the photosensitive component whose absorption of light having a wavelength of 500 nm increases with time.

For example, in the (B) naphthoquinonediazide esterified product (PAC: photosensitive component), the benzophenone based PAC tends to increase the absorbance of light with a wavelength of 500 nm over time. Therefore, the color value can be reduced by reducing the amount of benzophenone based PAC. On the other hand, the esterification reaction product (non-benzophenone-based PAC) of the non-benzophenone based phenolic hydroxyl group-containing compound with the 1,2-naphthoquinone diazidesulfonic acid compound exhibited an absorbance of light with a wavelength of 500 nm Tends to be difficult to increase, and also contributes to improvement in properties such as resolution, and therefore, this is essential in the present invention. If the blending amount is increased and the blending amount of the other photosensitive component is decreased, the color value can be reduced.

&Lt; Component (A) >

The component (A) is not particularly limited, and one or two or more selected from those which can be commonly used as a film-forming material in a positive type photoresist composition can be selected and used.

For example, it is possible to use phenols (phenol, m-cresol, p-cresol, xylenol, trimethylphenol and the like) and aldehydes (formaldehyde, formaldehyde precursor, propionaldehyde, 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, Hydroxybenzaldehyde, etc.) and / or ketones (methyl ethyl ketone, acetone, etc.) in the presence of an acidic catalyst;

A hydroxystyrene type resin such as a homopolymer of hydroxystyrene, a copolymer of hydroxystyrene and another styrenic monomer, or a copolymer of hydroxystyrene and acrylic acid or methacrylic acid or a derivative thereof;

Acrylic acid or methacrylic acid-based resin, which is a copolymer of acrylic acid or methacrylic acid and a derivative thereof.

Particularly novolacs obtained by condensation reaction of phenols containing at least two members selected from m-cresol, p-cresol, 3,4-xylenol and 2,3,5-trimethylphenol and aldehydes containing formaldehyde, It is suitable for adjustment of a resist material having high sensitivity and excellent resolution.

The component (A) can be prepared by a conventional method.

The mass average molecular weight of the component (A) in terms of polystyrene determined by gel permeation chromatography may vary depending on the kind thereof, but it is 2000 to 100000, preferably 3000 to 30000 in terms of sensitivity and pattern formation.

&Lt; Component (B) >

(B) is not limited as long as it contains an esterification reaction product (non-benzophenone-based PAC) of a non-benzophenone-based compound containing a phenolic hydroxyl group and a 1,2-naphthoquinone diazidesulfonic acid compound, The photoresist composition is not particularly limited as long as it is used as a photosensitive component and may be used alone or in combination of two or more.

The non-benzophenone based PAC is represented by the following general formula (I):

[Wherein R ¹ ~R ⁸ represents a cycloalkyl group each independently a hydrogen atom, an alkoxy group of the alkyl group, of 1 to 6 carbon atoms, a halogen atom, a 1 to 6 carbon atoms, or carbon atoms 3~6; R ^10, R ¹¹ represents a hydrogen atom or an alkyl group of 1 to 6 carbon atoms independently; R ⁹ may be a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, in which case Q ¹ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms Or a residue represented by the following formula (II):

(Wherein R ¹² and R ¹³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms; c is 1 represents an integer of from to 3) it is, or Q ¹ may be bonded with the terminal of R ^9, in which case Q ¹ is a carbon chain of 3 to 6 together with the carbon atoms between Q ¹ and R ⁹ and R ⁹ A and b each represent an integer of 1 to 3; d represents an integer of 0 to 3; when a, b, or d is 3, R ³ , R ⁶ or R ⁸ are absent; n represents an integer of 0 to 3]

And a 1,2-naphthoquinone diazidesulfonic acid compound are preferable because the color value of the phenol compound and the 1,2-naphthoquinone diazidesulfonic acid compound can be reduced.

The non-benzophenone based PAC is suitable for photolithography using i-line and is suitable for forming a fine resist pattern of 2.0 m or less under a low NA condition in a good shape. That is, it is preferable from the viewpoint of high resolution and also preferable from the viewpoint of linearity.

In addition, the resist composition which is not adjusted to have a color value of 0.15 or less even with the use of a non-benzophenone based PAC can not attain the effect of the present invention.

Further, in forming a cycloalkyl group of 3 to 6 carbon chain taken together with the carbon atoms between Q ¹ and Q ¹ is R ⁹ and R ⁹ is, by combining the Q ¹ and R ⁹ forms an alkylene group of a carbon number of 2 to 5 .

Examples of the compound corresponding to the general formula (I) include tris (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy- Dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis 4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy- Dihydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis Dihydroxyphenylmethane, bis (4-hydroxyphenyl) -3-methoxy-4-hydroxyphenylmethane, bis (4-hydroxyphenyl) -Cyclohexyl-4- (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy -2-methylphenyl) -2-hydroxyphenylmethane, and bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane;

Bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol, and the like. Cyclohexylphenyl] isopropane, bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) (4-hydroxybenzyl) -4-hydroxyphenyl] methane, bis [2,5-dimethyl- (3,5-dimethyl-4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- Ethyl] phenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4-hydroxy- Hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy-3- -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) ] Methane and bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4- hydroxyphenyl] methane; 2,4-bis [2-hydroxy 3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [ Linear 5-core phenol compounds such as 6-cyclohexylphenol and 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4- hydroxybenzyl] Linear polyphenol compounds such as &lt; RTI ID = 0.0 &gt;

Bis (2,4-dihydroxyphenyl) methane, 2,3,4-trihydroxyphenyl-4'-hydroxyphenylmethane, 2- ( (2 ', 3', 4'-trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (4-hydroxyphenyl) propane, 2- (3-fluoro-4-hydroxyphenyl) propane, 2- (4'-hydroxyphenyl) propane, 2- (2,3,4-tetrahydroxyphenyl) propane, 2- Dihydroxyphenyl) -2- (4'-hydroxy-3 ', 5'-dimethylphenyl) -2- ) Propane; 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] Hydroxyphenyl) cyclo And the like can be condensed phenol compound of the acid, and the like.

These may be used alone or in combination of two or more.

Among them, it is preferable to use a trisphenol-type compound as a main component from the viewpoint of high sensitivity and resolution, and especially bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane (B1 ') and bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane [hereinafter referred to as (B3')]. For the purpose of adjusting a resist composition having excellent total balance of resist characteristics such as resolution, sensitivity, heat resistance, DOF characteristics, and linearity, a linear polyphenol compound, a bisphenol compound, a polynuclear branched compound, (2,4'-dihydroxyphenyl) methane [hereinafter referred to as (B2 ')] is used in combination with a phenol-type compound, and in particular, a bisphenol-type compound, especially bis have.

Hereinafter, the naphthoquinonediazide esterified product of each of the above-mentioned (B1 '), (B2') and (B3 ') is abbreviated as (B1), (B2) and (B3).

(B1) and (B3) are used, the blending amount in the component (B) is preferably 10% by mass or more, more preferably 15% by mass or more. Further, it may be 90 mass% or less, preferably 85 mass% or less, respectively.

When all of (B1), (B2) and (B3) are used, the blending amount of each component is preferably 50 to 90 mass%, more preferably 60 to 80 mass% The blending amount is 5 to 25 mass%, preferably 10 to 15 mass%, and the blending amount of (B3) is 5 to 25 mass%, preferably 10 to 15 mass%.

The naphthoquinonediazidesulfonic acid esterification of all or a part of the phenolic hydroxyl group of the compound represented by the above general formula (I) can be carried out by a conventional method.

For example, it can be obtained by condensing naphthoquinonediazide sulfonyl chloride with the compound represented by the above general formula (I).

Specifically, for example, the compound represented by the above-mentioned general formula (I) and the naphthoquinone-1,2-diazide-4 (or 5) -sulfonyl chloride are reacted with dioxane, n-methylpyrrolidone, Acetamide, tetrahydrofuran and the like, and at least one basic catalyst such as triethylamine, triethanolamine, pyridine, alkali carbonate or alkali hydrogen carbonate is added to the reaction mixture, and the resulting product is washed with water , And dried.

As the component (B), other preferred PACs other than the preferred bibenzophenone based PACs may be used. For example, benzophenone based PACs such as polyhydroxybenzophenone may also be used.

However, the amount of PAC (especially benzophenone-based PAC) other than the non-benzophenone based PAC is preferably small from the viewpoint of adjustment of the color value.

For example, the non-benzophenone-based PAC is preferably 50 mass% or more, more preferably 80 mass% or more in the component (B).

The amount of the component (B) in the photoresist composition is 20 to 70 mass%, preferably 25 to 60 mass%, based on the total amount of the component (A) and the component (C).

By making the blending amount of the component (B) at least the lower limit value, an image faithful to the pattern is obtained and the transferability is improved. By setting the content at or below the upper limit, the deterioration of the sensitivity can be prevented, the homogeneity of the formed resist film is improved, and the resolution is improved.

&Lt; Component (C) >

The sensitivity is improved by using the component (C). In particular, high sensitivity, high resolution, and further improved linearity can be obtained in an i-line exposure process under a low NA (numerical aperture) condition.

The molecular weight of the component (C) is preferably 1000 or less, preferably 700 or less, practically 200 or more, and preferably 300 or more in view of the above effect.

As the component (C), a phenolic hydroxyl group-containing compound which is generally used in a resist composition as a sensitivity enhancing agent or sensitizer is not particularly limited as long as it satisfies the above-mentioned molecular weight requirements, Can be arbitrarily selected and used. Among them, the following general formula (III):

[Wherein R ²¹ ~R ²⁸ represents a cycloalkyl group each independently a hydrogen atom, an alkoxy group of the alkyl group, of 1 to 6 carbon atoms, a halogen atom, a 1 to 6 carbon atoms, or carbon atoms 3~6; R ^30, R ³¹ is each independently a hydrogen atom or an alkyl group of 1 to 6 carbon atoms; R ²⁹ may be a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, in which case Q ² is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms Or a moiety represented by the following formula (IV):

(Wherein R ³² and R ³³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms; g is 0 It represents an integer of from to 3) and Q ² or may be bonded with the terminal of R ^29, in which case the carbon chain of 3 to 6 together with the carbon atoms between Q ² is R ²⁹ and Q ² and R ²⁹ E and f each independently represent an integer of 1 to 3; h represents an integer of 0 to 3; and when e, f or h is 3, R ²³ , R ²⁶ or R ²⁸ are absent; m represents an integer of 0 to 3]

Lt; / RTI &gt; of the present invention preferably exhibits the above properties.

Specifically, for example, in addition to the phenol compound used in the naphthoquinone diazide esterified product of the phenol compound exemplified as the component (B), bis (3-methyl-4-hydroxyphenyl) Methane, bis (3-methyl-4-hydroxyphenyl) -phenylmethane, bis (2-methyl-4-hydroxyphenyl) Bis (3-ethyl-4-hydroxyphenyl) -phenylmethane, bis (2-methyl- And bis (2-tert-butyl-4,5-dihydroxyphenyl) -phenylmethane can be suitably used. Among them, bis (2-methyl-4-hydroxyphenyl) -phenylmethane, 1- [1- (4- hydroxyphenyl) isopropyl] -4- [ ] Benzene is preferred.

The blending amount of the component (C) is in the range of 10 to 70 mass%, preferably 20 to 60 mass% with respect to the component (A) from the viewpoint of the effect.

<Organic solvents>

The organic solvent (hereinafter, referred to as component (D)) may be selected from one or more of those selected from those generally used in photoresist compositions without particular limitation, but propylene glycol monoalkyl ether acetate and / or 2-heptanone Is preferable from the viewpoint of excellent coatability and uniformity of the film thickness of the resist film on the large glass substrate.

Both of propylene glycol monoalkyl ether acetate and 2-heptanone may be used, but it is preferable that they are used individually or in combination with other organic solvents from the viewpoint of film thickness uniformity at the time of coating using the spin coat method or the like many.

The propylene glycol monoalkyl ether acetate is preferably contained in an amount of 50 to 100 mass% in the component (D).

The propylene glycol monoalkyl ether acetate is, for example, one having a linear or branched alkyl group having 1 to 3 carbon atoms. Among them, propylene glycol monomethyl ether acetate (hereinafter referred to as PGMEA) This is particularly preferable because the film thickness uniformity is very excellent.

On the other hand, 2-heptanone is not particularly limited, but it is a suitable solvent when it is combined with a photosensitive component of the non-benzophenone type as the (B) naphthoquinone diazide ester.

2-heptanone is a highly preferable solvent because of its excellent heat resistance as compared with PGMEA and the ability to provide a resist composition with reduced occurrence of scum.

When 2-heptanone is used alone or in combination with other organic solvents, it is preferably contained in 50 to 100% by mass of the component (D).

Further, other preferred solvents may be mixed with other solvents.

For example, mixing lactic acid acrylate such as methyl lactate and ethyl lactate (preferably ethyl lactate) is preferable because it can form a resist pattern having excellent film thickness uniformity and excellent shape.

When a mixture of propylene glycol monoalkyl ether acetate and alkyl lactate is used, it is preferable to mix the alkyl lactate in an amount of 0.1 to 10 times, preferably 1 to 5 times, in terms of the mass ratio with respect to propylene glycol monoalkyl ether acetate.

Organic solvents such as? -Butyrolactone and propylene glycol monobutyl ether may also be used.

When? -butyrolactone is used, it is preferably blended in an amount of 0.01 to 1 part by mass, preferably 0.05 to 0.5 parts by mass with respect to propylene glycol monoalkyl ether acetate.

Specific examples of the organic solvent that can be blended include the following.

Examples of the solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone and methyl isoamyl ketone; alcohols such as ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate, Monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether; cyclic ethers such as dioxane; and organic solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate , Esters such as methyl methoxypropionate and ethyl ethoxypropionate.

When these solvents are used, 50 mass% or less of the components (D) is preferable.

To the positive-working photoresist composition of the present invention may be added, if necessary, additives which are compatible with the purpose of the present invention, for example, an additive resin for improving the performance of a resist film, a plasticizer, Active agents, coloring agents for making the developed images more visible, dyes for improving the sensitizing effect, dyes for preventing halation, and adhesion improvers.

Examples of the dye for preventing halation include ultraviolet absorbers (for example, 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dimethylamino-2', 4'-dihydroxybenzophenone, (4-hydroxyphenyl azo) pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylamino-4'- Aminobenzene, curcumin, etc.) can be used.

Surfactants can be added for prevention of strain or the like, and examples thereof include fluororad FC-430, FC431 (trade name, manufactured by Sumitomo 3M Co., Ltd.), Efstop EF122A, EF122B, EF122C, EF126 , XR-104, Megapack R-08 (trade name, manufactured by Dainippon Ink and Chemicals, Incorporated), and the like can be used.

The positive-working photoresist composition of the present invention is preferably prepared by dissolving (A), (B), (C) and optionally other components in (D) an organic solvent, Followed by heat treatment.

It is preferable to adjust the temperature and time so that the color value becomes 0.15 or less in the heat treatment. The heating temperature is, for example, 50 to 85 占 폚, and the heating time varies depending on the temperature, but is, for example, 30 minutes to 24 hours.

In order to reduce the color value, it is preferable to heat it under stable conditions as much as possible.

The amount of the component (D) to be used can be suitably adjusted so as to obtain a uniform positive-type photoresist composition by dissolving a solid component [component (A) to component (C) and other components to be used as needed]. Preferably, the solid content is used in an amount of 10 to 50% by mass, more preferably 20 to 35% by mass.

It is preferable that the positive type photoresist composition of the present invention is prepared such that the Mw of the solid content (hereinafter referred to as resist molecular weight) included in the resist composition is in the range of 5,000 to 30,000, more preferably 6,000 to 10,000 . By setting the molecular weight of the resist to the above range, it is possible to obtain a positive-working photoresist composition which can achieve high resolution without lowering the sensitivity, excellent in linearity and DOF characteristics, and excellent in heat resistance.

If the molecular weight of the resist is less than the above range, the resolution, linearity, DOF characteristics, and heat resistance become insufficient. If the molecular weight exceeds the above range, the sensitivity is markedly lowered and the applicability of the resist composition may be impaired.

In the present specification, the values measured using the following GPC system are used as the molecular weight of the resist.

Device name: SYSTEM 11 (product name, manufactured by Showa Denko KK)

Free column: KF-G (product name, manufactured by Shodex)

Column: KF-805, KF-803, KF-802 (product name, manufactured by Shodex)

Detector: UV41 (product name, manufactured by Shodex), measured at 280 nm.

Solvent etc.: Tetrahydrofuran is poured at a flow rate of 1.0 ml / min and measured at 35 ° C.

Measuring sample preparation method: The photoresist composition to be measured is adjusted to have a solid content concentration of 30% by mass and diluted with tetrahydrofuran to prepare a measurement sample having a solid content concentration of 0.1% by mass. 20 μl of the measurement sample is injected into the apparatus and measured.

As a method of preparing the positive photoresist composition of the present invention so that the molecular weight of the resist is in the above-described preferable range, for example, (A) before the mixing so that the Mw after mixing the whole components falls within the above range, (2) a method in which a plurality of components (A) having different Mws are prepared and appropriately blended, and the Mw of the solid content is adjusted to the above range And the like.

Among these preparation methods, the preparation method according to (2) above is more preferable from the viewpoint of easy adjustment of the resist molecular weight and sensitivity adjustment.

[Method of forming resist pattern]

Hereinafter, an example of a suitable method for forming a resist pattern when manufacturing an LCD is described.

First, the above-described positive photoresist composition of the present invention is applied to a substrate by a spinner or the like to form a coating film. The substrate is preferably a glass substrate. As the glass substrate, amorphous silica is usually used, and in the field of system LCD, a glass substrate on which a low temperature polysilicon layer is formed is considered to be preferable. As this glass substrate, since the positive type photoresist composition of the present invention is excellent in resolution under low NA conditions, a large substrate having a size of 500 mm x 600 mm or larger, particularly 550 mm x 650 mm or larger can be used.

Subsequently, the glass substrate on which the coating film is formed is heat-treated (pre-baked) at, for example, 100 to 140 占 폚, and the residual solvent is removed to form a resist film. As the pre-baking method, it is preferable to perform the proximity baking with a gap between the hot plate and the substrate.

Further, the resist film is selectively exposed using a mask having a mask pattern drawn thereon.

As the light source, it is preferable to use an i-line (365 nm) in order to form a fine pattern. The exposure process adopted in this exposure is preferably an exposure process with a low NA condition, wherein the NA is 0.3 or less, preferably 0.2 or less, more preferably 0.15 or less.

Subsequently, heat treatment (post exposure bake: PEB) is performed on the resist film after selective exposure. Examples of the PEB method include a proximity bake having a gap between the hot plate and the substrate and a direct bake having no gap. In order to obtain a diffusion effect by PEB without bending the substrate, Is preferable. The heating temperature is preferably 90 to 150 占 폚, particularly preferably 100 to 140 占 폚.

When the resist film after PEB is subjected to a development treatment using an alkaline aqueous solution such as a developing solution, for example, 1 to 10 mass% tetramethylammonium hydroxide solution, the exposed portion is dissolved and removed to form a resist pattern for an integrated circuit A resist pattern for a liquid crystal display portion is formed at the same time.

In addition, a resist pattern can be formed by rinsing the developing solution remaining on the surface of the resist pattern with a rinsing liquid such as pure water.

In the method of forming the resist pattern, in the case of manufacturing the system LCD, in the step of performing the selective exposure, both the mask pattern for forming a resist pattern of 2.0 m or less and the mask pattern for forming a resist pattern of more than 2.0 m You can use a drawn mask.

Further, since the positive type photoresist composition for LCD of the present invention is excellent in resolution, a resist pattern in which a fine pattern of a mask pattern is faithfully reproduced can be obtained. Therefore, in the step of simultaneously forming the resist pattern, a resist pattern for an integrated circuit having a pattern dimension of 2.0 m or less and a resist pattern for a liquid crystal display part of more than 2.0 m can be simultaneously formed on the substrate.

(Example)

Hereinafter, the present invention will be described in detail with reference to examples.

The evaluation method used in this embodiment is as follows.

(1) Linearity evaluation:

A positive photoresist composition was applied on a glass substrate (550 mm x 650 mm) on which a Ti film was formed by using a resist coating apparatus for a large substrate (apparatus name: TR36000, manufactured by Dooka Corporation) The first drying was performed for 90 seconds by a proximity bake at 100 캜 with an interval of about 1 mm. Subsequently, the temperature of the hot plate was set at 90 캜, and by a proximity bake at intervals of 0.5 mm, And dried for the second time to form a resist film having a film thickness of 1.48 mu m.

Subsequently, an i-line exposure apparatus (equipment name: FX-702J, Nikon Corporation) was exposed through a test chart mask (reticle) in which a mask pattern for simulating a resist pattern of 3.0 μm line and space (L & S) (NA = 0.14) manufactured by Mitsubishi Rayon Co., Ltd., was selectively exposed with an exposure dose (Eop exposure dose) capable of faithfully reproducing 1.5 占 퐉 L & S.

Subsequently, the temperature of the hot plate was set at 120 占 폚, the heat treatment was performed for 30 seconds by a proximity bake at an interval of 0.5 mm, and then the heat treatment was performed for 60 seconds by direct baking at the same temperature.

Subsequently, a 2.38% by mass aqueous solution of TMAH (aqueous solution of tetramethylammonium hydroxide) at 23 占 폚 was subjected to a developing device (device TD-39000 demo machine, manufactured by Toyo Kaio Corporation) having a slit coater nozzle, , The solution was held on the substrate for 10 seconds from the end X of the substrate to the end of the substrate along the line Z for 55 seconds and then washed with water for 30 seconds and dried by spin.

Thereafter, the cross-sectional shape of the obtained resist pattern was observed with an SEM (scanning electron microscope) photograph, and the reproducibility of the resist pattern of 3.0 mu m L & S was evaluated.

A that has a dimensional change rate of ± 10% or less, B that is more than 10% and 15% or less, and C that is more than 15%.

(2) Sensitivity evaluation:

And the exposure dose (Eop exposure dose: unit mJ) capable of faithfully reproducing 1.5 占 퐉 L & S.

(3) Evaluation of DOF characteristics:

The depth of focus (DOF) (total depth width) obtained in the range of the dimensional change rate of 1.5 占 퐉 L & S by 10% by shifting the focal point appropriately up and down in the Eop exposure amount was obtained in the unit of 占 퐉.

(4) Resolution evaluation:

The critical resolution at the Eop exposure was determined.

(Examples 1 to 4 and Comparative Examples 1 to 4)

The materials shown in Table 1 were mixed in the proportions shown in Table 1 to prepare a resist composition.

The symbols for the materials in Table 1 represent the following compounds.

Mw = 20000 and Mw / Mn = 5.2, which were synthesized by a conventional method using 1 mole of mixed phenol of A1 / m-cresol / 3,4-xylenol = 8/2 (molar ratio) and 0.82 mole of formaldehyde Novolac resin

B1: 1 mol of bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane (B1 ') and 1 mol of 1,2- (Hereinafter referred to as (5-NQD)), 2 mol of the esterification reaction product

B2: Esterification reaction product of 1 mole of bis (2,4-dihydroxyphenyl) methane (B2 ') and 2 moles of 5-NQD

B3: esterification reaction product of 1 mole of bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane (B3 ') with 2 moles of 5-NQD

C1: bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane

Organic solvent (D): D1: PGMEA

Examples and comparative examples in which the materials are mixed and heat-treated when adjusting the resist composition are as follows.

Example: Heating temperature 70 占 폚, heating time 15 minutes

Comparative Example: heating temperature 75 占 폚, heating time 60 minutes

The evaluation results are shown in Table 2.

(A) Ingredient (compounding amount) ^{* 1} (B) Component (mixing ratio) ^{※ 2} (compounding amount) ^{※ 1} (C) Component (compounding amount) ^{* 1} Organic solvent (compounding) ^{* 1} Resist Molecular Weight Color value Example 1 A1 (15) B1 (5.5) C1 (4.5) D1 (75) 10000 0.03 Example 2 Homology B1 / B2 (mixing ratio 6/1) (mixing ratio 5.5) Homology Homology Homology 0.04 Example 3 Homology B1 / B2 (mixing ratio 1/1) (mixing ratio 5.5) Homology Homology Homology 0.04 Example 4 Homology B3 (compounding ratio 5.5) Homology Homology Homology 0.04 Comparative Example 1 Homology B2 (compounding ratio 5.5) Homology Homology Homology 0.20 Comparative Example 2 Homology B1 / B2 (mixing ratio 6/1) (mixing ratio 5.5) Homology Homology Homology 0.23 Comparative Example 3 Homology B1 / B2 (mixing ratio 1/1) (mixing ratio 5.5) Homology Homology Homology 0.22 Comparative Example 4 Homology B1 (compounding ratio 5.5) Homology Homology Homology 0.19 ※ 1 Mixture amount: Gillange, ※ 2 Mixing ratio: Mass ratio

Linearity Sensitivity (mJ) DOF (탆) Resolution (㎛) Example 1 A 30 20 1.3 Example 2 A 35 22 1.2 Example 3 A 50 24 1.2 Example 4 A 60 24 1.2 Comparative Example 1 A 70 16 1.4 Comparative Example 2 A 50 18 1.3 Comparative Example 3 A 75 20 1.3 Comparative Example 4 A 45 16 1.4

Thus, the linearity, the sensitivity, the DOF characteristic, and the resolution are good in the embodiments of the present invention.

INDUSTRIAL APPLICABILITY As described above, the present invention provides a positive photoresist composition and a method of forming a resist pattern which are excellent in resolution and DOF characteristics, are suitable for i-line exposure, excellent in linearity and sensitivity, can do.

Claims (3)

(A) an alkali-soluble resin, (B) a naphthoquinone diazide esterified compound, and (C) a phenolic hydroxyl group-containing compound having a molecular weight of 1000 or less, in an organic solvent, Wherein the component (B) contains an esterification reaction product of a non-benzophenone-based compound containing a phenolic hydroxyl group and a 1,2-naphthoquinone diazidesulfonic acid compound, When the color value of the resist composition is 0.15 or less Wherein the integrated circuit and the liquid crystal display portion are formed on one substrate. (1) a step of applying a positive-working photoresist composition according to claim 1 onto a substrate to form a coating film; (2) a step of forming a resist film on the substrate by heat treatment (prebaking) ) Performing a selective exposure on the resist film using a mask in which both a mask pattern for forming a resist pattern of 2.0 탆 or less and a mask pattern for forming a resist pattern of more than 2.0 탆 are drawn, (4) (5) a step of subjecting the resist film after the heat treatment to a development process using an aqueous alkali solution, and forming a resist pattern for an integrated circuit having a pattern dimension of 2.0 m or less on the substrate, And a step of simultaneously forming a resist pattern for a liquid crystal display portion of more than 2.0 mu m Forming a resist pattern according to claim. The method for forming a resist pattern according to claim 2, wherein the step (3) of performing the selective exposure is carried out by using an i-line as a light source and an exposure process under a low NA condition in which the NA is 0.3 or less .

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