KR20040100912A - Positive photoresist composition and resist pattern formation method - Google Patents

Abstract

PURPOSE: Provided are a positive type resist composition for preparation of a substrate where an integrated circuit and a liquid crystal display part are formed, which has satisfactory sensitivity, an excellent heat resistance and high resolution, and a method for forming a resist pattern by using the composition. CONSTITUTION: The positive type resist composition comprises an alkali-soluble resin; a quinonediazide group-containing compound; a phenolic hydroxyl group-containing compound with a molecular weight of 1,000 or less; and an organic solvent, wherein the solid part contained in the resist composition has a polystyrene reduced weight average molecular weight by gel permeation chromatography of 5,000-30,000. Preferably the quinonediazide group-containing compound comprises a product by the esterification of a phenolic hydroxyl group-containing compound represented by the formula I and a 1,2-naphthoquinonediazide-5-sulfonyl compound, wherein R1 to R8 are independently H, a halogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, or a C3-C6 cycloalkyl group; R10 and R11 are independently H or a C1-C6 alkyl group; R9 can be H or a C1-C6 alkyl group and in this case Q1 is H, a C1-C6 alkyl group or a residue represented by the formula II, or Q1 can combine the terminal of R9 and in this case Q1 represents a C3-C6 cycloalkyl group together with R9 and the carbon atom between Q1 and R9; a and b are an integer of 1-3; d is an integer of 0-3; and n is an integer of 0-3. In the formula II, R12 and R13 are independently H, a halogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, or a C3-C6 cycloalkyl group; and c is an integer of 1-3.

Description

Formation method of positive resist composition and resist pattern {POSITIVE PHOTORESIST COMPOSITION AND RESIST PATTERN FORMATION METHOD}

The present invention relates to a positive type resist composition for manufacturing a substrate having an integrated circuit and a liquid crystal display portion formed on one substrate, and a resist pattern forming method using the same.

As resist materials in the field of manufacturing liquid crystal display devices using glass substrates, alkali-soluble resins are suitable for ghi line exposure and can be formed with relatively low cost and excellent resistivity, resolution, and shape. A positive resist composition using a novolak resin and using a quinonediazide group-containing compound as a photosensitive component has been widely used and reported (Japanese Patent Laid-Open Nos. 2000-131835, 2001-75272, 2000-181055, 2000-112120).

Until now, since the purpose was to form the pixel portion of the display, a very rough pattern (for example, about 3 to 5 μm) can be formed, and the polystyrene reduced mass average molecular weight (Mw) by the gel permeation chromatography method. The positive resist composition which is 4000 or less was used.

Currently, a high-performance LCD called "System LCD", in which integrated circuit parts such as drivers, DACs (digital analog converters), image processors, video controllers, and RAM are formed simultaneously with the display part as next generation LCDs. Development is active (Semiconductor FPD World 2001.9, pp.50-67).

Hereinafter, in the present specification, 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.

Such a system LCD is suitable for low temperature polysilicon formed by a low temperature process of 600 ° C. or lower in place of amorphous silicon as a substrate in terms of lower electric resistance and higher mobility than amorphous silicon.

Therefore, development of a resist composition suitable for the production of a system LCD using low temperature polysilicon as a substrate is desired, but there have been no reported examples of resist materials for system LCDs.

In order to manufacture a TFT made of low temperature polysilicon, a polysilicon film is formed on a glass substrate by a low temperature process, and then, in a so-called "implantation process" in which P or B is injected into the low temperature polysilicon film, the concentration is very high. It is necessary to inject impurities.

This implantation process is performed under a high vacuum condition in which a resist pattern is formed on a low temperature polysilicon glass substrate on which a low temperature polysilicon film is formed on a glass substrate, but the resist pattern on the substrate is heated by an exothermic action by implantation of impurities. In this case, there is a problem that the resist pattern causes a shape change or any component of the resist pattern is gasified to lower the vacuum degree in the processing chamber.

As a means to solve this problem, it is effective to perform a heat treatment step called "post bake" before the implantation step, but this post bake is, for example, 200 ° C under a temperature condition close to the temperature heated at the time of implantation. Since it is performed at the high temperature mentioned above, formation of the highly heat resistant resist pattern which does not change a pattern shape in the said heat processing is essential. Therefore, in order to realize manufacture of a system LCD, it is required that heat resistance is favorable as a resist composition used for it.

Further, in the system LCD, for example, the pattern dimension of the display portion is about 2 to 10 µm, whereas the integrated circuit portion is formed to have a fine dimension of about 0.5 to 2.0 µm. Therefore, the resist composition for system LCD manufacture requires the ability (linearity) to simultaneously form a fine pattern and a rough pattern in a good shape simultaneously, and is higher resolution than the conventional LCD material resist material, and the depth of focus of a fine pattern is required. It is strictly required that the width (DOF) characteristic be good.

However, in the manufacturing field of the liquid crystal element, the decrease in sensitivity in the resist material is not preferable because it causes a significant throughput drop, and it is preferable to improve the above characteristics without causing a decrease in sensitivity.

The present invention provides a resist composition capable of improving the heat resistance, resolution, linearity and DOF characteristics required for the manufacture of a system LCD in which an integrated circuit and a liquid crystal display portion are formed on one substrate without degrading the sensitivity and a resist pattern using the same. It is an object of the present invention to provide a method of forming a film.

(Means to solve the task)

In order to solve the said subject, the positive resist composition for system LCDs of this invention is (A) alkali-soluble resin, (B) quinone diazide group containing compound, (C) molecular weight (M) whose phenolic hydroxyl group containing compound is 1000 or less. And (D) a resist composition comprising an organic solvent, characterized in that the polystyrene reduced mass average molecular weight (Mw) by gel permeation chromatography of solid content contained in the resist composition is in the range of 5000 to 30000.

Moreover, this invention is the process of (1) apply | coating said positive photoresist composition on a board | substrate, and forming a coating film, (2) process of heat-processing (prebaking) the board | substrate with the said coating film, and forming a resist film on a board | substrate, ( 3) a step of selectively exposing the resist film using a mask on which a resist pattern forming mask pattern of 2.0 μm or less and a resist pattern forming mask pattern of more than 2.0 μm are drawn, (4) the selective exposure (5) Process of heat-resisting (post exposure bake) to the resist film after the said resist film, development process using alkaline aqueous solution is performed to the resist film after the said heat-processing (post exposure bake), and the pattern dimension of 2.0 micrometers or less is integrated on the said board | substrate. Simultaneously forms a resist pattern for circuits and a resist pattern for liquid crystal display portions larger than 2.0 mu m It provides a method of forming a resist pattern comprising the step of.

As a value of the mass mean molecular weight (Mw) in this specification, the value measured using the following GPC system is used.

Device name: SYSTEM 11 (Product name, Showa Electric Works)

Precolumn: KF-G (Product name, manufactured by Shodex)

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

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

Solvent etc .: It measures at 35 degreeC by flowing tetrahydrofuran at the flow volume 1.0 ml / min.

Measurement 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.

(Embodiment of invention)

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

[(A) component]

The component (A) is not particularly limited, and may be optionally used one or two or more of alkali-soluble resins that can be commonly used as a film forming material in the positive resist composition.

For example, phenols (phenol, m-cresol, p-cresol, xyleneol, trimethylphenol, etc.) and aldehydes (formaldehyde, formaldehyde precursors, propionaldehyde, 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, Novolak resin obtained by condensing 4-hydroxybenzaldehyde etc.) and / or ketones (methyl ethyl ketone, acetone etc.) in presence of an acidic catalyst;

Hydroxystyrene resins such as homopolymers of hydroxystyrene, copolymers of hydroxystyrene with other styrene monomers, copolymers of hydroxystyrene with acrylic acid or methacrylic acid or derivatives thereof;

Acrylic acid or methacrylic acid resin which is a copolymer of acrylic acid or methacrylic acid, and its derivative (s) is mentioned.

In particular, novolak resins obtained by condensation of phenols containing m-cresol, p-cresol, 3,4-xylenol and 2,3,5-trimethylphenol and aldehydes containing formaldehyde have good heat resistance. They are suitable because they are relatively inexpensive and available.

(A) component can be manufactured according to a conventional method.

The polystyrene-converted mass average molecular weight (hereinafter referred to as Mw only) by gel permeation chromatography of component (A) may vary depending on its type, but is 2000 to 100,000 in terms of sensitivity and pattern formation, preferably 3000 to 3000. 30000 is preferred.

[(B) component]

(B) component is a quinonediazide group containing compound. The component (B) is not particularly limited as long as it is a quinonediazide group-containing compound which is generally used as a photosensitive component in a positive resist composition, and may be used alone or in combination of two or more thereof.

Especially, when a non-benzophenone type compound is used, it is suitable for the photolithography using i line | wire, and is also preferable at the point of high resolution and linearity.

As such a nonbenzophenone (B) component, the ester compound of the phenol compound represented by following General formula (I) and a naphthoquinone diazide sulfonic-acid compound is preferable. As a naphthoquinone diazide sulfonic-acid compound, a 1, 2- naphthoquinone diazide-5-sulfonyl compound is preferable.

[Wherein, R ¹ to R ⁸ 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; R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; 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 Q ¹ may be bonded to the terminal of R ⁹ , in which case Q ¹ may be R ⁹ and a cyclo of 3 to 6 carbon atoms together with a carbon atom between Q ¹ and R ^9. An alkyl group; a and b represent the integer of 1-3; d represents an integer of 0 to 3; n represents an integer of 0 to 3]

In addition, Q ¹ and R ⁹ and in the case where the cycloalkyl group of 3 to 6 carbon chain to form together with the carbon atoms between Q ¹ and R ^9, Q ¹ and R ⁹ may be combined to form an alkylene group having a carbon number of 2 to 5 Doing.

As a phenolic compound corresponding to the said General formula (I), tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3- methylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-) 2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5- Dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -4- Hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2,4-dihydroxyphenylmethane, bis (4-hydroxyphenyl) -3-methoxy-4-hydroxyphenylmethane, bis (5-cyclo Hexyl-4-hydride Cy-2-methylphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy- Trisphenol type compounds, such as 2-methiphenyl) -2-hydroxyphenylmethane and bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane;

2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol, 2,6-bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol Linear trinuclear phenol compounds; 1,1-bis [3- (2-hydroxy-5-methylbenzyl) -4-hydroxy-5-cyclohexylphenyl] isopropane, bis [2,5-dimethyl-3- (4-hydroxy- 5-methylbenzyl) -4-hydroxyphenyl] methane, bis [2,5-dimethyl-3- (4-hydroxybenzyl) -4-hydroxyphenyl] methane, bis [3- (3,5-dimethyl -4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4- Hydroxy-5-ethylphenyl] methane, bis [2-hydroxy-3- (3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy-3- (2 -Hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [2,5-dimethyl Linear tetranuclear phenol compounds such as -3- (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] methane; 2,4-bis [2-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [4-hydroxy-3- (4-hydroxy Hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4 Linear polyphenol compounds such as linear pentanuclear phenol compounds such as -methyl phenol;

Bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) methane, 2,3,4-trihydroxyphenyl-4'-hydroxyphenylmethane, 2- ( 2,3,4-trihydroxyphenyl) -2- (2 ', 3', 4'-trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2 ', 4'-dihydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (3-fluoro-4-hydroxyphenyl) -2- ( 3'-fluoro-4'-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,3,4-tri Hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (4'-hydroxy-3 ', 5'-dimethylphenyl) Bisphenol-type compounds such as propane; 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, 1- [1- (3-methyl-4-hydroxyphenyl Multinuclear branched compounds such as) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene; Condensation type phenol compounds, such as 1, 1-bis (4-hydroxyphenyl) cyclohexane, etc. are mentioned.

These can be used 1 type or in combination or 2 or more types.

Especially, it is preferable to make a trisphenol type compound into a main component from the point of high sensitivity and resolution, and it is especially bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane [following] (B1 ')] and bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane [hereinafter referred to as (B3')] are preferable. In addition, for the purpose of adjusting a resist composition having excellent total balance of resist characteristics such as resolution, sensitivity, heat resistance, DOF characteristics, linearity, and the like, the above-described tris may be used as a linear polyphenol compound, a bisphenol type compound, a multinuclear branched compound, and a condensed phenol compound. It is preferable to use together with a phenol type compound. Especially, when using a bisphenol type compound, especially bis (2, 4- dihydroxy phenyl) methane (henceforth (B2 ')), the resist composition excellent in the total balance can be adjusted. have.

In addition, the naphthoquinone diazide esterified product of each of said (B1 '), (B2'), (B3 ') is abbreviated as (B1), (B2), (B3).

When using (B1) and (B3), it is preferable that the compounding quantity in (B) component is 10 mass% or more and 15 mass% or more, respectively.

In addition, when using all of (B1), (B2), and (B3), each compounding quantity is 50-90 mass% of (B1), Preferably it is 60-80 mass%, (B2) from an effect point. The compounding quantity is 5-20 mass%, Preferably it is 10-15 mass%, The compounding quantity of (B3) becomes 5-20 mass%, Preferably it is 10-15 mass%.

The naphthoquinone diazide sulfonic-acid esterification method of all or one part of the phenolic hydroxyl group of the compound represented by the said General formula (I) can be performed by a conventional method.

For example, it can obtain by condensing naphthoquinone diazide sulfonyl chloride with the compound represented by the said General formula (I).

Specifically, for example, the compound represented by the general formula (I) and naphthoquinone-1,2-diazide-5-sulfonyl chloride are dioxane, n-methylpyrrolidone, dimethylacetamide, and tetrahydro. A predetermined amount is dissolved in an organic solvent such as furan, and at least one basic catalyst such as triethylamine, triethanolamine, pyridine, alkali carbonate, and alkali hydrogen carbonate is added to the reaction to wash and dry the product. Can be.

As the component (B), as described above, other naphthoquinone diazide ester compounds can be used in addition to the above-described preferred naphthoquinone diazide ester compounds, for example, polyhydroxybenzophenone, alkyl gallate, or the like. The esterification reaction product of the phenol compound and naphthoquinone diazide sulfonic acid compound, etc. can also be used.

It is preferable that it is 80 mass% or less in (B) photosensitive component, and, as for the usage-amount of these other naphthoquinone diazide ester-ized thing, it is especially preferable at the point of the effect improvement of this invention that it is 50 mass% or less.

The compounding quantity of (B) component in a resist composition becomes 20-70 mass% with respect to the total amount of (A) component and the following (C) component, Preferably it is 25-60 mass%.

By making the compounding quantity of (B) component more than the said lower limit, the image faithful to a pattern is obtained and transferability improves. Deterioration of a sensitivity can be prevented by setting it below the said upper limit, the homogeneity of the formed resist film improves, and the effect that resolution improves is acquired.

[(C) component]

(C) component is a phenolic hydroxyl group containing compound. By using this (C) component, the outstanding sensitivity improvement effect is acquired.

The molecular weight (M) of (C) component is 1000 or less, Preferably it is 700 or less, and it is preferable from a point of the said effect that a lower limit is 200 or more substantially, Preferably it is 300 or more.

The component (C) is a phenolic hydroxyl group-containing compound generally used in a resist composition as a sensitivity improving agent or a sensitizer, and is not particularly limited as long as it satisfies the conditions of the above molecular weight. Can be used arbitrarily selected. Among them, non-benzophenone-based compounds not only provide excellent sensitivity enhancement effects but also high sensitivity and high resolution in the i-ray exposure process. Thus, especially in the manufacture of LCDs or the production of system LCDs using the i-ray exposure process. As appropriate, higher resolution and linearity can be achieved.

As such a nonbenzophenone type (C) component, the phenolic compound represented by following General formula (III) is preferable.

[Wherein, R ²¹ to R ²⁸ 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; R ³⁰ and R ³¹ each independently represent a hydrogen atom or an alkyl group having 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 residue 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 Q ² may be bonded to the terminal of R ²⁹ , in which case Q ² is R ²⁹ and a cyclo of 3 to 6 carbon atoms together with a carbon atom between Q ² and R ^29. An alkyl group; e and f represent the integer of 1-3; h represents an integer of 0 to 3; m represents an integer of 0 to 3]

Specifically, for example, bis (3-methyl-4-hydroxyphenyl) -4-isopropylphenyl in addition to the phenolic compound used in the naphthoquinone diazide ester compound of the phenolic compound illustrated in the said (B) component. Methane, bis (3-methyl-4-hydroxyphenyl) -phenylmethane, bis (2-methyl-4-hydroxyphenyl) -phenylmethane, bis (3-methyl-2-hydroxyphenyl) -phenylmethane, Bis (3,5-dimethyl-4-hydroxyphenyl) -phenylmethane, bis (3-ethyl-4-hydroxyphenyl) -phenylmethane, bis (2-methyl-4-hydroxyphenyl) -phenylmethane, Trisphenyl type compounds, such as bis (2-tert- butyl- 4, 5- dihydroxy phenyl) -phenylmethane, can be used suitably. Among them, bis (2-methyl-4-hydroxyphenyl) -phenylmethane and 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl ] Benzene is preferred.

The compounding quantity of (C) component becomes 10-70 mass% with respect to (A) component from the point of an effect, Preferably it becomes the range of 20-60 mass%.

[(D) component]

The component (D) may be any one or two or more kinds of organic organic solvents used in the resist composition, without particular limitation. However, the component containing propylene glycol monoalkyl ether acetate and / or 2-heptanone may be coated. It is preferable in that it is excellent in this and excellent in the film thickness uniformity of the resist film on a large glass substrate.

In addition, although both propylene glycol monoalkyl ether acetate and 2-heptanone can be used, it is preferable to use it individually or in mixture with another organic solvent from the point of film uniformity at the time of application | coating using a spin coat method etc. many.

It is preferable to contain 50-100 mass% of propylene glycol monoalkyl ether acetates in (D) component.

The propylene glycol monoalkyl ether acetate has, for example, a linear or branched alkyl group having 1 to 3 carbon atoms, among which propylene glycol monomethyl ether acetate (hereinafter also referred to as PGMEA) is a film of a resist film on a large glass substrate. It is especially preferable because thickness uniformity is very excellent.

On the other hand, although 2-heptanone is not specifically limited, It is a solvent suitable when using the non-benzophenone type photosensitive component represented by the said General formula (I) as a (B) quinonediazide group containing compound.

2-heptanone is a very preferable solvent because it has excellent heat resistance compared to PGMEA and provides a resist composition with reduced scum generation.

When using 2-heptanone individually or in mixture with another organic solvent, it is preferable to contain 50-100 mass% in (D) component.

Moreover, you may use it, mixing another solvent with these preferable solvents.

For example, when alkyl lactate, such as methyl lactate and ethyl lactate (preferably ethyl lactate), is mix | blended, it is preferable because it can form the resist pattern excellent in the film thickness uniformity of a resist film, and excellent in shape.

When using a mixture of propylene glycol monoalkyl ether acetate and alkyl lactate, it is preferable to mix | blend 0.1-10 times, preferably 1-5 times the amount of alkyl lactate with respect to propylene glycol monoalkyl ether acetate.

Moreover, organic solvents, such as (gamma) -butyrolactone and a propylene glycol monobutyl ether, can also be used.

When using gamma -butyrolactone, it is preferable to mix | blend in the range of 0.01-1 time, preferably 0.05-0.5 time by mass ratio with respect to propylene glycol monoalkyl ether acetate.

Moreover, as an organic solvent which can be mix | blended other, the following are mentioned specifically ,, for example.

Namely, ketones such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isoamyl ketone; Ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate or polyhydric compounds such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Alcohols and derivatives thereof; Cyclic ethers such as dioxane; And esters such as methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate and ethyl ethoxypropionate.

When using these solvents, it is required to be 50 mass% or less in (D) component.

In the positive resist composition of the present invention, additives, plasticizers, preservative stabilizers, surfactants for improving the performance of the additives, for example, the resist film, etc., which are compatible as necessary within the scope of not impairing the object of the present invention. And conventional additives such as colorants for making the developed image more visible, sensitizers for improving the sensitizing effect, anti-halation dyes, and adhesion improving agents.

As a dye for prevention of halation, a ultraviolet absorber (for example, 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dimethylamino-2', 4'-dihydroxybenzophenone, 5-amino- 3-methyl-1-phenyl-4- (4-hydroxyphenylazo) pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylamino-4'-ethoxyazobenzene, 4-diethyl Aminoazobenzene, curcumin, etc.) can be used.

Surfactant can be added, for example for anti-stressing, For example, Fluorade FC-430, FC431 (brand name, the Sumitomo 3M Corporation make), F-top EF122A, EF122B, EF122C, EF126 (brand name) And fluorine-based surfactants such as Tochem Products Co., Ltd., Megapack R-08 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), and the like.

The positive resist composition of the present invention is preferably prepared by dissolving the component (A), the component (B), the component (C) and, if necessary, other components in the organic solvent (D). The usage-amount of (D) component, Preferably it adjusts suitably so that a uniform positive resist composition may be obtained when melt | dissolving (A)-(C) component and other components used as needed. Preferably it is used so that solid content concentration may be 10-50 mass%, More preferably, it is 20-35 mass%. Moreover, solid content of a positive resist composition is corresponded to the sum total of (A)-(C) component and the other component used as needed.

The positive resist composition of this invention is prepared so that Mw of solid content contained in this resist composition may be in the range of 5000-30000, More preferable Mw is 6000-10000. By setting Mw of solid content of this resist composition in the said range, high heat resistance and high resolution can be achieved without reducing a sensitivity, and the positive resist composition excellent in linearity and DOF characteristics is obtained.

If the Mw of the solid content of the resist composition is smaller than the above range, the heat resistance, resolution, linearity, and DOF characteristics will be insufficient, and if it exceeds the above range, the decrease in sensitivity will be remarkable, and the applicability of the resist composition may be impaired.

Moreover, in system LCD manufacturing, there exists a tendency to improve the resolution by using the photolithography technique which used the shorter wavelength i line | wire (365 nm) exposure instead of g line | wire (436 nm) exposure conventionally used for manufacture of LCD. On the other hand, especially in the photoresist composition which uses a non-benzophenone type compound as (B) component and / or (C) component, since absorption of i line | wire by the (B) component and / or (C) component is suppressed, It is suitable for the i-ray exposure process, and further high resolution can be realized.

The preparation method of the positive resist composition of this invention has a process of preparing so that Mw may become said suitable range. As a method of performing such a step, Mw of the component (A) is adjusted to an appropriate range in advance, for example, by performing a fractionation operation on the component (A) before mixing so that the Mw after mixing all the components is in the above range. There is a way to do it.

[Formation method of resist pattern]

An example of a suitable formation method of a resist pattern at the time of manufacturing a system LCD using the positive resist composition of this invention is shown below.

First, the positive resist composition of this invention mentioned above is apply | coated to a board | substrate with a spinner etc., and a coating film is formed. As the substrate, a glass substrate is preferable. Amorphous silica is usually used as the glass substrate, and low temperature polysilicon is considered to be preferable in the field of system LCD.

Subsequently, the glass substrate on which this coating film was formed is heat-processed (prebaked), for example at 90-140 degreeC, and a residual solvent is removed and a resist film is formed. As a prebaking method, it is preferable to perform the proximity baking which forms the clearance gap between a hotplate and a board | substrate.

In addition, selective exposure is performed using a mask having a mask pattern drawn on the resist film.

As a light source, in order to form a fine pattern, it is preferable to use i line (365 nm). In addition, it is preferable that the exposure process employ | adopted by this exposure is the exposure process of the low NA condition whose NA is 0.3 or less, Preferably it is 0.2 or less, More preferably, it is 0.15 or less. By employing an exposure process in a low NA condition, it is possible to take a wide exposure area per shot and improve throughput.

Next, heat treatment (post exposure bake: PEB) is performed on the resist film after selective exposure. The PEB method may include a proximal bake that forms voids between the hot plate and the substrate, and a direct bake that does not form voids. The PEB method may be used in order to obtain a diffusion effect by PEB without bending the substrate. The method of performing direct baking is preferable. Moreover, 90-150 degreeC is preferable and 100-140 degreeC of heating temperature is especially preferable.

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

Further, the resist pattern can be formed by washing the developer remaining on the surface of the resist pattern with a rinse solution such as pure water.

In the method of forming a resist pattern, in manufacturing a system LCD, both a resist pattern forming mask pattern of 2.0 µm or less and a mask pattern forming resist pattern of more than 2.0 µm are used as the mask in the step of performing the selective exposure. You can use a painted mask.

Since the positive resist composition for LCDs of this invention is excellent in linearity, the resist pattern which faithfully reproduced both the rough pattern and the fine pattern of a mask pattern is obtained. For this reason, the resist pattern for integrated circuits with a pattern dimension of 2.0 micrometers or less and the resist pattern for liquid crystal display parts larger than 2.0 micrometers can be simultaneously formed on a board | substrate.

(Example)

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

[Evaluation Method of Positive Resist Composition]

The evaluation method of the following general physical properties (1)-(5) about the positive resist composition of the following Example or a comparative example is shown below.

(1) Sensitivity evaluation: 90 degreeC and 90 degree after apply | coating positive type resist composition on a silicon wafer (550 mm x 650 mm) using the resist coating apparatus for large substrates (the apparatus name: TR36000 Tokyo Ogyo Co., Ltd. make). Prebaking was performed by proximity baking with a space of about 1 mm under the heating conditions for a second to form a resist film having a film thickness of 1.5 탆.

Subsequently, an i-line exposure apparatus (device name: FX-702J, manufactured by Nikon Corporation) through a test chart mask (reticle) on which a resist pattern of 1.5 µm L & S and a mask pattern for reproducing a resist pattern of 3.0 µm L & S were simultaneously drawn; NA = 0.14) was used for selective exposure at an exposure amount (Eop exposure amount) that can faithfully reproduce 1.5 µm L & S.

Subsequently, PEB was performed by proximity breach with the space | interval of 0.5 mm on 120 degreeC and the conditions for 90 second.

Subsequently, after developing for 60 second using 23 degreeC and 2.38 mass% TMAH aqueous solution, it rinsed with pure water for 30 second and spin-dried.

As an index of sensitivity evaluation, an exposure amount (Eop, unit: mJ) capable of faithfully reproducing a resist pattern of 1.5 µm L & S was used.

(2) Evaluation of DOF characteristics: In the above Eop exposure amount, the width of the depth of focus (DOF) obtained in the range of 1.5 µm L & S within a range of dimensional change of ± 10% was determined by shifting the focus up and down appropriately. .

(3) Heat resistance evaluation: The cross-sectional shape was observed after leaving the board | substrate with 3.0 micrometers L & S drawn on the hotplate set to 140 degreeC for 300 second in the said Eop exposure amount. As a result, it was found that the rate of dimensional change of 3.0 µm L & S was within ± 3%. , And those in the range of 3 to 5% or -5 to -3% were indicated by Δ and more than ± 5%.

(4) Resolution evaluation: The limit resolution in the said Eop exposure amount was calculated | required.

(5) Linearity evaluation: The cross-sectional shape of the resist pattern of 3.0 micrometers L & S obtained by the said Eop exposure amount was observed with the SEM (scanning electron microscope) photograph, and the reproducibility of the resist pattern of 3.0 micrometers L & S was evaluated. Dimensional change rate of 3.0㎛ L & S is within ± 10% , And those in the range of 10 to 15% or -15 to -10% were indicated by Δ, and more than ± 15%.

(Examples 1-7, Comparative Examples 1-4)

The following were prepared as (A)-(D) component.

(A) Alkali Soluble Novolak Resin:

(a1) Mw = 12000, Mw / Mn = 4.7 synthesized by a conventional method using 1 mole of mixed phenol of m-cresol / 3,4-xylen = 8/2 (molar ratio) and 0.76 mole of formaldehyde. Novolak resin

(a2) Mw = 17000 and Mw / Mn = 5 synthesized by a conventional method using 1 mole of mixed phenol of m-cresol / 3,4-xyllen = 8/2 (molar ratio) and 0.8 mole of formaldehyde. Novolak resin

(a3) Mw = 20000, Mw / Mn = 5.2 synthesized by a conventional method using 1 mole of mixed phenol of m-cresol / 3,4-xylol = 8/2 (molar ratio) and 0.82 mole of formaldehyde. Novolak resin

(a4) Mw = 25000 and Mw / Mn = 5.5 synthesized by a conventional method using 1 mole of mixed phenol of m-cresol / 3,4-xyllen = 8.5 / 1.5 (molar ratio) and 0.85 mole of formaldehyde. Novolak resin

(a5) Mw = 30000, Mw / Mn = 5.8 synthesized by a conventional method using 1 mole of mixed phenol of m-cresol / 3,4-xylol = 8.5 / 1.5 (molar ratio) and 0.87 mole of formaldehyde. Novolak resin

(a6) Mw = 35000 and Mw / Mn = 6.1 synthesized by a conventional method using 1 mole of mixed phenol of m-cresol / 3,4-xyllen = 9/1 (molar ratio) and 0.89 mole of formaldehyde. Novolak resin

(a7) Mw = 40000, Mw / Mn = 6.4 synthesized by a conventional method using 1 mole of mixed phenol of m-cresol / 3,4-xylenol = 9/1 (molar ratio) and 0.91 mole of formaldehyde. Novolak resin

(a8) Novolak resin of Mw = 7000 and Mw / Mn = 3 synthesize | combined by the conventional method using 1 mol of mixed phenols of m-cresol / p-cresol = 9/1 (molar ratio), and 0.73 mol of formaldehyde.

(a9) Novolak resin of Mw = 9000 and Mw / Mn = 3.2 synthesize | combined by the conventional method using 1 mol of mixed phenols of m-cresol / p-cresol = 9/1 (molar ratio), and 0.75 mol of formaldehyde.

(a10) Novolak resin of Mw = 45000 and Mw / Mn = 6.7 synthesize | combined by the conventional method using 1 mol of mixed phenols of m-cresol / p-cresol = 9.5 / 0.5 (molar ratio), and 0.92 mol of formaldehyde.

(a11) Novolak resin of Mw = 50000 and Mw / Mn = 7 synthesize | combined by the conventional method using 1 mol of mixed phenols of m-cresol / p-cresol = 9.5 / 0.5 (molar ratio), and 0.95 mol of formaldehyde.

(B) quinonediazide group containing compound:

1 mole of (B1) bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane (B1 ') and 1,2-naphthoquinone diazide-5-sulfonyl Esterification product with 2 moles of chloride [hereinafter referred to as (5-NQD)]

(B2) esterification product of 1 mole of bis (2,4-dihydroxyphenyl) methane (B2 ') with 2 moles of 5-NQD

(B3) esterification reaction product of 1 mole of bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane (B3 ') with 5 moles of 5-NQD2

(C) Phenolic hydroxyl group-containing compound: (C1) bis (2-methyl-4-hydroxyphenyl) -phenylmethane

(D) Organic Solvent: PGMEA

Surfactant (product name "MegaPak R-08") using the said (A)-(C) component in the compounding quantity of following Table 1, and an amount equivalent to 450 ppm with respect to the total mass of these (A)-(C) component. Dainippon Ink and Chemicals Co., Ltd.) were dissolved in the component (D) shown in Table 1 below, and further filtered using a membrane filter having a pore diameter of 0.2 µm to prepare a positive resist composition. . In Table 1, (//) has shown that it is a mixture mixed in the mass ratio described there.

Each item of said (1)-(5) was evaluated about the obtained positive resist composition, respectively. The results are shown in Table 2 below.

Mw of resist composition A component (mixture) B component (combination amount) C component (mixture) D component (mixture) Example 1 5000 a1 (15) B1 / B2 / B3 [75 / 12.5 / 12.5 (molar ratio)] (5.5) C (4.5) PGMEA (75) Example 2 7000 a2 (15) Same as above Same as above Same as above Example 3 10000 a3 (15) Same as above Same as above Same as above Example 4 15000 a4 (15) Same as above Same as above Same as above Example 5 20000 a5 (15) Same as above Same as above Same as above Example 6 25000 a6 (15) Same as above Same as above Same as above Example 7 30000 a7 (15) Same as above Same as above Same as above Comparative Example 1 3000 a8 (15) Same as above Same as above Same as above Comparative Example 2 4000 a9 (15) Same as above Same as above Same as above Comparative Example 3 35000 a10 (15) Same as above Same as above Same as above Comparative Example 4 40000 a11 (15) Same as above Same as above Same as above

Sensitivity (mJ) DOF (μm) Heat resistance Resolution (μm) Linearity Example 1 40 16 1.3 Example 2 50 17 1.2 Example 3 70 17 1.2 Example 4 90 16 1.2 Example 5 110 16 1.3 Example 6 130 16 1.3 Example 7 150 16 1.3 Comparative Example 1 10 10 × 1.5 × Comparative Example 2 20 12 × 1.5 × Comparative Example 3 250 11 1.4 Comparative Example 4 350 10 1.4

As described above, since the positive resist composition of the present invention has good sensitivity, excellent heat resistance, and high resolution is obtained, it is suitable for system LCD manufacture and the throughput can be improved.

In addition, since the linearity is excellent, a rough pattern and a fine pattern can be formed on the same substrate under the same exposure conditions. Therefore, since the resist pattern of the display portion of the system LCD and the integrated circuit portion finer than that can be obtained at the same time in high resolution, it is suitable for system LCD manufacture.

In addition, in the positive resist composition for system LCD, although the width of the depth of focus is somewhat important in terms of manufacturing efficiency, controllability of manufacturing conditions, and the like, according to the present invention, the depth of focus that can be used for system LCD is practical. Width (for example, 15 micrometers or more) can be achieved.

Claims (6)

A resist composition comprising (A) an alkali-soluble resin, (B) a quinonediazide group-containing compound, (C) a phenolic hydroxyl group-containing compound having a molecular weight (M) of 1000 or less, and (D) an organic solvent. Positive photoresist for substrate production, wherein the integrated circuit and the liquid crystal display portion are formed on one substrate, characterized in that the polystyrene reduced mass average molecular weight (Mw) by gel permeation chromatography of the solid content contained is within the range of 5000 to 30000. Composition. The said (B) component contains the esterification reaction product of the phenolic hydroxyl group containing compound and 1,2-naphthoquinone diazide-5-sulfonyl compound represented by following formula (I). A positive resist composition characterized by the above. [Wherein, R ¹ to R ⁸ 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; R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; 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 Q ¹ may be bonded to the terminal of R ⁹ , in which case Q ¹ may be R ⁹ and a cyclo of 3 to 6 carbon atoms together with a carbon atom between Q ¹ and R ^9. An alkyl group; a and b represent the integer of 1-3; d represents an integer of 0 to 3; n represents an integer of 0 to 3] A positive resist composition according to claim 1, wherein the component (C) contains a phenolic hydroxyl group-containing compound represented by the following formula (III). [Wherein, R ²¹ to R ²⁸ 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; R ³⁰ and R ³¹ each independently represent a hydrogen atom or an alkyl group having 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 residue 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 Q ² may be bonded to the terminal of R ²⁹ , in which case Q ² is R ²⁹ and a cyclo of 3 to 6 carbon atoms together with a carbon atom between Q ² and R ^29. An alkyl group; e and f represent the integer of 1-3; h represents an integer of 0 to 3; m represents an integer of 0 to 3] The positive type resist composition according to claim 1, wherein the component (D) contains propylene glycol monoalkyl ether acetate and / or 2-heptanone. (1) applying the positive photoresist composition according to any one of claims 1 to 4 onto a substrate to form a coating film; (2) heating the substrate on which the coating film is formed (prebaking) to resist on the substrate. Process of forming a film, (3) Process of selective exposure using the mask in which both the resist pattern formation mask pattern of 2.0 micrometers or less and the mask pattern for resist pattern formation more than 2.0 micrometer are drawn with respect to the said resist film. (4) heat treatment (post exposure bake) of the resist film after the selective exposure; (5) development treatment using an aqueous alkali solution is performed on the resist film after the heat treatment (post exposure bake). Resist patterns for integrated circuits with a pattern dimension of 2.0 μm or less, and resists for liquid crystal display portions exceeding 2.0 μm The method of forming a resist pattern comprises a step of forming a pattern at the same time. The method of forming a resist pattern according to claim 5, wherein the step (3) of performing selective exposure is performed by an exposure process using a line i as a light source and under a low NA condition where NA is 0.3 or less.