KR100632171B1 - Positive photoresist composition for manufacturing system lcd, manufacturing method for the positive photoresist and formation method of resist pattern - Google Patents

Abstract

A positive photoresist composition is provided that is suitable for LCD manufacture in which an integrated circuit and a liquid crystal display portion are formed on one substrate, which is high sensitivity and high heat resistance. This positive photoresist composition contains (A) alkali-soluble resin and (B) quinonediazide group containing compound, The said (A) component is a phenol compound (a1) represented by the following general formula (I), and the following It is a novolak resin synthesize | combined by the condensation reaction of mixed phenols and aldehydes containing the phenol compound (a2) represented by General formula (II).

System LCD, Photoresist Composition, Resist Pattern

Description

POSITIVE PHOTORESIST COMPOSITION FOR MANUFACTURING SYSTEM LCD, MANUFACTURING METHOD FOR THE POSITIVE PHOTORESIST AND FORMATION METHOD OF RESIST PATTERN}

1 is a pattern exposure method by applying a positive photoresist composition to a glass substrate, baking and drying to evaluate linearity under low NA conditions, and then using a developing device having a slit coater to contain the developer from the substrate end X to Z. An illustration of the thing.

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

Conventionally, as a resist material for manufacturing a liquid crystal display device (LCD) such as a thin film transistor (TFT), it is suitable for exposure to ghi lines (rays including all of g lines, h lines, and i lines), and is relatively inexpensive and has high sensitivity. Novolak resins are used as alkali-soluble resins, and novolak-naphthoquinonediazide-based resists using a naphthoquinone diazide group-containing compound as a photosensitive component (hereinafter also referred to as PAC) have been widely used (for example, Japanese Unexamined Patent Publication Nos. 2000-131835, 2001-75272, 2000-181055, 2000-112120).

The resist was generally a resist material only for forming a very rough pattern (about 3 to 5 mu m) for forming the pixel portion of the display.

However, as a next-generation LCD, a high-performance LCD called a "system LCD", in which integrated circuit parts such as a driver, a digital-to-analog converter (DAC), an image processor, a video controller, and a RAM are formed simultaneously with the display part, is formed on one glass substrate. Technology development is underway (for example, Semiconductor FPD World 2001.9, pp. 50-67). Hereinafter, in the present specification, an LCD in which an integrated circuit and a liquid crystal display portion are formed on one substrate as described above is called a system LCD for convenience.

As a substrate of such a system LCD, low temperature polysilicon, especially low temperature polysilicon formed in a low temperature process of 600 ° C. or less, is expected to be suitable in terms of low electrical resistance and high mobility compared to amorphous silicon, and thus low temperature polysilicon. There is an active development of a system LCD using a substrate for the substrate.

In the manufacture of system LCDs, the resist material has improved ability (linearity), high resolution, and depth of focus (DOF) characteristics of fine patterns of integrated circuit portions and coarse patterns of liquid crystal display portions at the same time. Improvement is strictly required. In addition, 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 heat resistance improvement is required for a so-called "implantation process" in which P or B is injected into the low temperature polysilicon film. do.

Moreover, in system LCD manufacture, the introduction of the i line (365 nm) exposure process is anticipated instead of the ghi line exposure conventionally used for forming a fine pattern. However, in the materials conventionally used for LCD production, for example, a material using a benzophenone-based PAC, application to the i-line exposure process is difficult, and therefore, a material suitable for i-line exposure is expected to be required.

As a material suitable for i line | wire exposure, the material using non-benzophenone series PAC is anticipated to be suitable. However, a material using non-benzophenone PAC has a difficulty in that it is highly sensitive. Degradation of the resist material sensitivity is undesirable because it results in fatal throughput degradation in the field of LCD manufacturing, including system LCDs.

In addition, since the high temperature treatment is performed in the heat treatment (post exposure bake) process and the implantation process when forming the resist pattern, the resist material also requires high heat resistance so that the pattern shape is not deformed in these processes.

Therefore, as a resist material for system LCD manufacture, a material with high sensitivity and high heat resistance is desired.

As a highly sensitive technique of a resist material, adjusting the kind and compounding ratio of the phenol which is one of the raw materials of a novolak resin can be considered. For example, when cresol is used as the phenol, the higher the ratio of p-cresol, the higher the ortho novolak resin is obtained, and the resin tends to be significantly degraded in sensitivity. Therefore, increasing the ratio of m-cresol in phenols improves sensitivity. However, when forming a resist pattern using the resist material manufactured using this novolak resin, there exists a problem that the residual film property after image development falls and also the resolution. Moreover, sensitivity also improves by increasing the ratio of o-cresol in phenols. However, when forming a resist pattern using the resist material manufactured using this novolak resin, there exists a problem that reproducibility of mask patterns, such as edge roughness of the resist pattern after image development, falls.

Moreover, although the means of using low molecular weight novolak resin can also be considered as another method of high sensitivity, the method has a problem that the heat resistance of a resist pattern is impaired, and neither of these methods is practically applicable.

This invention is made | formed in view of the said subject, and makes it a subject to provide the positive type photoresist composition suitable for system LCD manufacture which is high sensitivity and high heat resistance.

This invention is a positive photoresist composition containing (A) alkali-soluble resin and (B) quinonediazide group containing compound, Comprising: The said (A) component is following General formula (I):

[Wherein, R represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an allyl group or an aryl group; a represents an integer of 2 to 4; b represents 0 or an integer of 1 to 2 Phenol compound (a1) represented by], and the following general formula (II):

Containing a phenol compound (a2) represented by [wherein R represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an allyl group or an aryl group; c represents an integer of 1 to 3] It is a novolak resin synthesize | combined by condensation reaction of mixed phenols and aldehydes, The positive photoresist composition for LCD manufacture in which the integrated circuit and the liquid crystal display part were formed on one board | substrate is provided.

Moreover, this invention is a 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) performing selective exposure to the resist film by using a mask on which both a resist pattern forming mask pattern of 2.0 µm or less and a mask pattern for forming resist pattern of more than 2.0 µm are drawn; (4) the selective exposure; (5) developing the resist film after the heat treatment using an aqueous alkali solution, and forming a resist pattern for an integrated circuit having a pattern dimension of 2.0 μm or less on the substrate; And simultaneously forming a resist pattern for liquid crystal display portions larger than 2.0 μm. A method of forming a resist pattern is provided.

(Embodiment of the Invention)

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

<< Positive type photoresist composition for system LCD manufacture >>

Positive type photoresist composition of this invention is alkali-soluble novolak resin obtained using mixed phenols containing a specific at least 2 type of phenolic compound as (A) component.

<(A) component>

(A) component is alkali synthesize | combined by the condensation reaction of the mixed phenols and aldehydes containing the phenol compound (a1) represented by general formula (I) and the phenol compound (a2) represented by general formula (II). It is a soluble novolak resin.

In general formula (I), R can mention C1-C3 alkyl groups, such as a methyl group, an ethyl group, and a propyl group; C1-C3 alkoxy groups, such as a methoxy group, an allyl group, an aryl group, etc. are mentioned especially, An alkyl group having 1 to 3 carbon atoms is preferable.

As a phenol compound (a1) represented by general formula (I), 1, 2- dihydroxy benzene, 1, 3- dihydroxy benzene, 1, 4- dihydroxy benzene, 1, 2-, 3- trihydride Polyhydroxybenzenes such as hydroxybenzene, 1,2,4-trihydroxybenzene, 1,3,5-trihydroxybenzene, and R substituents in which a part of hydrogen atoms of the polyhydroxybenzene is substituted with R; Can be mentioned. Among them, 1,3-dihydroxybenzene is preferred in that the reaction rate is high in the synthesis of the novolak resin and the reactivity is not left as an unreacted monomer, and the uniformity of the condensation reaction is good.

In general formula (II), as mentioned above, a C1-C3 alkyl group; a C1-C3 alkoxy group; an allyl group; an aryl group etc. are mentioned, Especially, a C1-C3 alkyl group is preferable. Do.

As a phenolic compound (a2) represented by General formula (II), Cresols, such as m-cresol, o-cresol, and p-cresol; Xylene, such as 2, 5- xylenol and 3, 4- xylenol And trialkylphenols such as 2,3,5-trimethylphenol.

The compounding ratio of a phenol compound (a1) and a phenol compound (a2) becomes like this. Preferably it is 1: 99-50: 50 (molar ratio), More preferably, it is 5: 95-30: 70 (molar ratio). When the phenol compound (a1) is blended in an amount of 1 mol% or more with respect to the total of the phenol compound (a1) and the phenol compound (a2), the effect of high sensitivity is sufficiently obtained. On the other hand, if the phenol compound (a1) is 50 mol% or less, the residual film after development It is excellent and can form a resist pattern of high resolution.

There is no restriction | limiting in particular as aldehydes, The aldehydes conventionally used for manufacture of a novolak resin can be used, It is the thing to use the mixture (mixed aldehydes) of formaldehyde (f1) and other aldehydes (f2). It is suitable for the manufacture of resist materials with more excellent heat resistance.

Although there is no restriction | limiting in particular as aldehydes (f2), For example, the aldehyde which has bulky substituents, such as acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde, vanillin, is preferable. Especially, propionaldehyde and salicyaldehyde are preferable and propionaldehyde is more preferable.

By using these aldehydes together with formaldehyde (f1), the rotation potential energy of the main chain and the side chain of the novolak resin becomes high by the steric hindrance in the molecule | numerator of the novolak resin obtained, and it becomes possible to suppress free rotation, The improvement can exert an excellent effect.

The blending ratio of formaldehyde (f1) and aldehydes (f2) in the mixed aldehydes is preferably 50:50 to 90: 5 (molar ratio), and more preferably 60:40 to 90:10 (molar ratio). In addition, aldehydes (f2) may be used individually by 1 type, or may use 2 or more types.

The blending ratio of the mixed phenols and the aldehydes is preferably 1: 0.5 to 1: 1 (molar ratio), more preferably 1: 0.6 to 1: 0.95 (molar ratio) from the viewpoint of excellent properties.

Component (A) can be produced according to a conventional method, and can be synthesized, for example, by condensation reaction of mixed phenols and aldehydes in the presence of an acidic catalyst.

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

<(B) component>

(B) component is a quinonediazide group containing compound.

The component (B) is not particularly limited as long as it is generally used as a photosensitive component (PAC) in the positive photoresist composition, and may be used alone or in combination of two or more thereof. Especially, since the esterification reaction product (nonbenzophenone PAC) of a non-benzophenone series phenolic hydroxyl group containing compound and a 1, 2- naphthoquinone diazide sulfonyl compound is suitable for the photolithography using i line | wire, it is preferable. Do. Moreover, it is suitable for the case where it is excellent in the resolution under low NA conditions, and wants to form a resist pattern in a favorable shape. Moreover, it is preferable also from a viewpoint of linearity and DOF.

As the 1,2-naphthoquinone diazide sulfonyl compound, a 1,2-naphthoquinone diazide-4-sulfonyl compound and / or a 1,2-naphthoquinone diazide-5-sulfonyl compound are preferable. Do.

As a phenolic hydroxyl group containing compound of a nonbenzophenone type, it is the following general formula (III):

[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 R ¹¹ each independently represents 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 represents a hydrogen atom or 1 to 6 carbon atoms. Alkyl group or the following general formula (IV):

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; denotes a residue represented by an integer from 1 to 3), or Q ¹ may be bonded with the terminal of R ^9, in which case Q ^1, together with the carbon atoms between Q ¹ and R ⁹ and R ⁹ A cycloalkyl group having 3 to 6 carbon atoms; d, e represent an integer of 1 to 3; g represents an integer of 0 to 3; and when d, e or g is 3, R ³ , R ⁶ and R are respectively; ⁸ shall be absent; n represents an integer of 0 to 3].

In addition, Q ¹ and R ⁹ and in the case of forming a cycloalkyl group of 3 to 6 carbon chain taken 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 (III), 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 Cyclohexyl-4-hydride Hydroxy-2-methylphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy- Trisphenol-type compounds such as 2-methylphenyl) -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 phenolic 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-hydrate Hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [2-hydroxy-3- (3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy Hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphen Linear quaternary phenolic compounds such as nyl] methane and bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] methane; 2,4-bis [2-hydride Hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [4-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] Linear pentanuclear phenols such as -6-cyclohexylphenol, 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4-methylphenol Linear polyphenol compounds such as compounds;

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 have a trisphenol-type compound as a main component from a viewpoint 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 properties such as resolution, sensitivity, heat resistance, DOF properties, and linearity, the trisphenol may be used as the linear polyphenol compound, bisphenol type compound, multinuclear branched compound, and condensed phenol compound. It is preferable to use together with a type | mold compound, and especially the bisphenol type compound, especially bis (2, 4- dihydroxy phenyl) methane (henceforth (B2 ')] can be used together, and the resist composition excellent in the total balance can be adjusted. .

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. Further, each may be 90 mass% or less, preferably 85 mass% or less.

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 a viewpoint of an effect. The compounding amount is 5-25 mass%, Preferably it is 10-15 mass%, The compounding quantity of (B3) becomes 5-25 mass%, Preferably it is 10-15 mass%.

The naphthoquinone diazide sulfonic acid esterification method of all or part of the phenolic hydroxyl group of the compound represented by the said general formula (III) 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 (III).

Specifically, for example, the compound represented by the above general formula (III) and naphthoquinone-1,2-diazide-4 (or 5) -sulfonyl chloride are converted into dioxane, n-methylpyrrolidone, and dimethyl. The product obtained by dissolving predetermined amount in organic solvents, such as acetamide and tetrahydrofuran, adding at least 1 type of basic catalysts, such as triethylamine, a triethanolamine, a pyridine, alkali carbonate, and an alkali hydrogen carbonate, and wash | cleans with water is obtained It can be manufactured by drying.

As the component (B), as described above, other naphthoquinone diazide esterates can be used in addition to the preferred naphthoquinone diazide ester compounds, and examples thereof include polyhydroxybenzophenone and alkyl gallate. The esterification reaction product of a phenol compound and a naphthoquinone diazide sulfonic acid compound, etc. can also be used.

It is preferable that the usage-amount of these other naphthoquinone diazide esterified products is 80 mass% or less, especially 50 mass% or less in (B) photosensitive component from a viewpoint of the improvement of the effect of this invention.

The compounding quantity of (B) component in a photoresist composition is 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 is improved is acquired.

<(C) component>

The positive photoresist composition of the present invention may further contain a phenolic hydroxyl group-containing compound having a (C) molecular weight of 1000 or less as a sensitizer in addition to the above-mentioned components (A) and (B). This (C) component is excellent in the sensitivity improvement effect, and by using (C) component, it is a high sensitivity and high resolution even in i line | wire exposure process in low NA (numerical aperture) conditions, and it is a suitable material for LCD manufacture, It is more preferable. Preferably, a material suitable for a system LCD having excellent linearity is obtained.

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

(C) As a component, it is a phenolic hydroxyl group containing compound generally used for a photoresist composition as a sensitivity improving material or a sensitizer, Preferably there is no restriction | limiting in particular if it satisfy | fills the conditions of the said molecular weight, 1 type or 2 types The above can be arbitrarily selected and used. And, among others, the following general formula (V):

[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 or 1 to 6 carbon group; Residue represented by an alkyl group or the following general formula (VI):

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; Q ² may be bonded to the terminal of R ²⁹ , in which case Q ² is selected from R ²⁹ and carbon atoms of 3 to 6 carbon atoms together with carbon atoms between Q ² and R ²⁹ . Cycloalkyl group; h, i represent an integer of 1 to 3; k represents an integer of 0 to 3; when h, i or k is 3, R ²³ , R ²⁶ or R ²⁸ is absent; m Represents an integer of 0 to 3].

Specifically, for example, bis (3-methyl-4-hydroxyphenyl) -4-isopropylphenylmethane and bis (3-in addition to the compound represented by general formula (III) illustrated by the said (B) component 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, bis (2-tert- Trisphenyl type compounds, such as butyl-4,5-dihydroxyphenyl) -phenylmethane, can be used conveniently. 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 is 10-70 mass% with respect to (A) component from a viewpoint of an effect, Preferably it is good to set it as the range of 20-60 mass%.

<Organic Solvents>

It is preferable that the positive photoresist composition of this invention contains the organic solvent further. Although the organic solvent can be used 1 type or 2 types or more without a restriction | limiting in particular if it is a general thing used for a photoresist composition, It is excellent in applicability | paintability containing propylene glycol monoalkyl ether acetate and / or 2-heptanone. It is preferable at the point which is 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 a viewpoint of the film thickness uniformity at the time of application | coating using a spin coat method etc., respectively. many.

It is preferable to contain 50-100 mass% of propylene glycol monoalkyl ether acetates in all the organic solvents.

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 used as a resist film on a large glass substrate. It is especially preferable because film thickness uniformity is very excellent.

On the other hand, 2-heptanone is not particularly limited, but as described above, 2-heptanone is a suitable solvent when combined with a nonbenzophenone-based photosensitive component.

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 2-heptanone is used individually or in mixture with another organic solvent, it is preferable to contain 50-100 mass% in all the organic solvents.

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 their mono Polyhydric alcohols and derivatives thereof such as methyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether; cyclic ethers such as dioxane; and methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate and ethyl pyruvate And esters such as methyl methoxy propionate and ethyl ethoxy propionate.

When using these solvents, it is preferable that they are 50 mass% or less in all the organic solvents.

<Other Ingredients>

In the positive type photoresist composition of the present invention, additives, plasticizers, storage stabilizers, interfaces 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. An active agent, a coloring agent for making the developed image more visible, and general additives such as a sensitizer, an antihalation dye, and an adhesion improving agent for improving the sensitizing effect can be contained.

Examples of the anti-halation dyes include ultraviolet absorbers (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 prevention of a strut, etc., 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., XR-104, MegaPac R-08 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), and the like.

<Manufacturing Method of Positive Photoresist>

The positive photoresist composition of the present invention can be produced, for example, by dissolving (A) to (C) components and other components in an organic solvent and filtering.

The amount of the organic solvent used is preferably an amount that can be appropriately adjusted so as to dissolve the components (A) to (C) and other components to obtain a uniform positive photoresist composition. Preferably it is used so that solid content [(A)-(C) component and other component] concentration is 10-50 mass%, More preferably, it is 20-35 mass%.

It is preferable that the positive photoresist composition of this invention is manufactured so that Mw of solid content contained in this resist composition (henceforth "resist molecular weight") exists in the range of 5000-30000, and more preferable Mw is 6000- 10000. By setting the resist molecular weight in the above range, a high heat resistance and high resolution can be achieved without degrading the sensitivity, and a positive photoresist composition excellent in linearity and DOF characteristics is obtained.

If the resist molecular weight 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 sensitivity will become remarkable and the applicability of the positive photoresist composition may be impaired.

As a method for producing the resist molecular weight to be in the above-mentioned suitable range, for example, the fractionation operation is performed on the component (A) before mixing so that Mw after mixing all the components becomes the above range, and the Mw of the component (A) is previously known. There exist a method of adjusting to the appropriate range, the method of preparing two or more (A) components from which Mw differs, mix | blending them suitably, and adjusting Mw of the solid content to the said range.

As a value of the resist molecular weight in this specification, the value measured using the following GPC system is used.

Device name: SYSTEM 11 (product name, Showa Denko manufacture)

Precolumn: KF-G (product name, Shodex company make)

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

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

Solvent etc .: It flows in tetrahydrofuran at flow rate 1.0 ml / min, and measures it at 35 degreeC.

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.

Since the positive photoresist composition of this invention mentioned above uses the novolak resin obtained using specific mixed phenols, heat resistance and sensitivity are improving. For this reason, it is suitable for system LCD manufacture which requires high heat resistance and high sensitivity. It is also a material that is more suitable for system LCD manufacture, such as excellent resolution and residual film properties after development and good resist characteristics such as depth of focus (DOF) characteristics and linearity.

Especially, when a non-benzophenone PAC is used as (B) component, a sensitivity further improves and it has high resolution also in the exposure process under low NA conditions, and also resist characteristics, such as DOF characteristic and linearity, are further improved.

Moreover, in system LCD manufacture, although it is anticipated to use i line | wire (365 nm) which is shorter than what is used for conventional LCD manufacture as mentioned above, in the positive photoresist composition of this invention, (B) component, In the case where the non-benzophenone-based compounds represented by the general formulas (III) and (V) are used as the component (C), the absorption of the i-line by the component (B) and the component (C) can be suppressed. It becomes a material suitable for an exposure process, and can realize high resolution further.

<< Formation method of resist pattern >>

A suitable example of the resist pattern forming method of the present invention is shown below.

First, the positive photoresist composition of the present invention described above is applied to a substrate with a spinner or the like to form a coating film.

As the substrate, a glass substrate is preferable. Amorphous silica is usually used as the glass substrate, but in the field of system LCD, a glass substrate having a low temperature polysilicon layer is considered to be preferable. As this glass substrate, since the positive photoresist composition of this invention is excellent in the resolution under low NA conditions, the large substrate of 500 mm x 600 mm or more, especially 550 mm x 650 mm or more can be used.

Subsequently, the glass substrate on which this coating film was formed is heated (prebaked) at 100-140 degreeC, for example, and a residual solvent is removed and a resist film is formed. As a prebaking method, it is preferable to perform a proximity baking with a space | interval between a hotplate and a board | substrate.

The resist film is selectively selected by using a mask on which both a resist pattern forming mask pattern of 2.0 μm or less corresponding to an integrated circuit portion and a resist pattern forming mask pattern of more than 2.0 μm corresponding to a liquid crystal display portion are drawn. It exposes.

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.

Next, heat treatment (post exposure bake: PEB) is performed on the resist film after selective exposure.

As PEB temperature, Preferably it is 90-150 degreeC, More preferably, it is 100-120 degreeC.

As the PEB method, any of the proximity bake having a gap between the hot plate and the substrate and the direct bake without a gap between the hot plate and the substrate can be used, but both are particularly preferable.

Especially, it is preferable to bake by direct baking after proximity baking. More specifically, a proxy having a gap of 0.05 to 5 mm, more preferably 0.1 to 1 mm at 90 to 150 ° C, more preferably at 100 to 120 ° C for 5 to 100 seconds, more preferably for 10 to 50 seconds. It is preferable to perform a direct bake with a gap of 0 mm after performing a mite bake at 90-150 degreeC, More preferably, 100-120 degreeC for 5 to 200 second, More preferably, 30 to 80 second.

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

Further, by washing off the developer remaining on the resist pattern surface with a rinse solution such as pure water, it is possible to simultaneously form a resist pattern for integrated circuits with a pattern dimension of 2.0 μm or less and a resist pattern for liquid crystal display portions larger than 2.0 μm on a substrate.

(Example)

Hereinafter, an Example is shown and this invention is demonstrated in detail.

Synthesis Example 1

The composition (molar ratio) is 1,3-dihydroxybenzene (a1) / m-cresol (a2) / 3,4- in a 1 l detachable flask equipped with a cooling tube, a Teflon® stirring blade, a thermometer and a dropping funnel. 1 mole of a mixture of phenols of xylenol (a2) / 2,3,5-trimethylphenol (a2) = 15/68 / 8.5 / 8.5 and 0.01 mole of p-toluenesulfonic acid dihydrate as an acid catalyst (Gamma) -butyrolactone was added and stirred so that the total concentration of phenols) might be 40 mass%. Then, the temperature of the oil bath was set to 100 degreeC. Subsequently, 37 mass% formalin aqueous solution (0.76 mol of formaldehyde content, formaldehyde (f1): propionaldehyde (f2) = 83.5: 16.5 (molar ratio)) which mixed 0.15 mol of propionaldehyde was dripped gradually over 30 minutes by dropping funnel. It was. Then, it stirred at the temperature of 100 degreeC for 12 hours, and after completion | finish of stirring, it cooled to room temperature (25 degreeC), wash | cleaned by adding butyl acetate, and the upper layer was concentrated to the evaporate, and the crude resin solution was obtained. The resin solution, methanol, and n-heptane were added to the separatory funnel, the mixture was left to stand, the lower layer was scraped off, PGMEA was added and concentrated to obtain a purified resin solution (A1). The polystyrene reduced mass average molecular weight (Mw) of the obtained resin was 10500.

Synthesis Examples 2 to 6

In Synthesis Example 1, the resin solution was prepared in the same manner as in Synthesis Example 1 except that the composition of the mixed phenols, the kind of aldehydes (f2), and the aldehydes (f1) / (f2) ratio were changed as shown in Table 1. A2) to (A6) were obtained. Table 1 writes Mw of each resin together. In addition, the symbol of Table 1 has the following meaning.

1,3-DHB ： 1,3-dihydroxybenzene

m-C ： m-cresol

3,4-XY: 3,4-xylenol

2,3,5-TMP ： 2,3,5-trimethylphenol

FA ： formaldehyde

PA: Propionaldehyde

SA ： Salicylate

Composition of Mixed Phenols Aldehydes (f1 / f2) Mw (Molar ratio) (a1 / a2) Synthesis Example 1 1,3-DHB / m-C / 3,4-XY / 2,3,5-TMP (15/68 / 8.5 / 8.5) 15/85 FA / PA (83.5 / 16.5) 10500 Synthesis Example 2 Same as above Same as above FA / SA (83.5 / 16.5) 10000 Synthesis Example 3 1,3-DHB / m-C / 3,4-XY (15/68/17) Same as above FA / PA (83.5 / 16.5) 10500 Synthesis Example 4 1,3-DHB / m-C / 3,4-XY / 2,3,5-TMP (15/68 / 8.5 / 8.5) Same as above FA 10000 Synthesis Example 5 m-C / 3,4-XY / 2,3,5-TMP (68 / 8.5 / 8.5) -/ 100 FA / PA (83.5 / 16.5) 11000 Synthesis Example 6 Same as above Same as above FA 11000

(Examples 1-4, Comparative Examples 1-2)

35 mass% of bis (2-methyl-4- hydroxyphenyl) phenylmethane was mix | blended as (C) component with respect to solid content of resin solution (A1)-(A6) obtained by the said synthesis examples 1-6. Subsequently, 30 mass% of mixed PAC of "(B1) / (B2) / (B3) = 6/1/1 (mass ratio)" as a component (B) was added with respect to the solid content of the said resin, and the total mass of (C) component. It was blended as much as possible. Subsequently, PGMEA was added and adjusted so that total solid concentration might be 25 mass%, and the photoresist composition was obtained. The photoresist composition was filtered through a 0.2 μm filter to adjust a resist coating liquid. The kind of resin solution used in Table 2 and the resist molecular weight of each resist coating liquid are shown.

In addition, said (B1)-(B3) are as follows.

(B1) 1 mole of bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane (B1 ') and 1,2-naphthoquinonediazide-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 product of 1 mol of bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane (B3 ') with 5-mol NQD2

Resin Solution Resist molecular weight Linearity Sensitivity (mJ) DOF (μm) Resolution (μm) Heat resistance Example 1 (A1) 5700 A 47.5 20 1.2 A Example 2 (A2) 5500 A 20 10 1.5 A Example 3 (A3) 5700 A 42.5 20 1.2 B Example 4 (A4) 5500 A 35 15 1.4 B Comparative Example 1 (A5) 6000 A 150 20 1.4 C Comparative Example 2 (A6) 6000 A 120 20 1.4 C

About the resist coating liquids obtained in Examples 1-4 and Comparative Examples 1-2, linearity, sensitivity, DOF, resolution, and heat resistance were evaluated in the following procedures, respectively. The results are written together in Table 2.

(Linearity evaluation)

The resist coating liquid was applied onto a glass substrate (550 mm x 650 mm) on which a Ti film was formed using a resist coating apparatus for large substrates (apparatus name: TR36000 manufactured by Tokyo Kogyo Co., Ltd.), and then the temperature of the hot plate was 100 ° C. First drying for 90 seconds by proximal bake with an interval of about 1 mm, followed by 90 seconds of second baking with proximal bake with a 0.5 mm interval of temperature of hot plate. Drying was performed once to form a resist film having a film thickness of 1.48 mu m.

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

Subsequently, the temperature of the hot plate was set to 120 ° C., and heated at a distance of 0.5 mm for 30 seconds by Proximity Bake, followed by heat treatment for 60 seconds by direct bake without intervals at the same temperature.

Subsequently, a developing apparatus (device name: TD-39000 demonstrator, TOKYO CO., LTD.) Which has a slit coater nozzle at 23 ° C. and a 2.38% by mass TMAH aqueous solution (product name “NMD-3” manufactured by TOKYO CO., LTD.) (Manufactured) was used to hold the liquid on the substrate for 10 seconds from the substrate end X to Z (see FIG. 1) for 55 seconds, and then washed with water for 30 seconds to spin-dry. Then, the cross-sectional shape of the obtained resist pattern was observed by SEM (scanning electron microscope) photograph, and the reproducibility of the resist pattern of 3.0 micrometers L & S was evaluated. A, the dimensional change rate is ± 10% or less, A, more than 10% to 15% or less, B, more than 15% is indicated as C.

(Sensitivity assessment)

It represented by the exposure amount (Eop; mJ / cm <2>) which can faithfully reproduce the 1.5 micrometers L & S resist pattern.

(DOF evaluation)

In the above exposure amount Eop, the depth of focus (total depth of width) obtained in a range in which the DOF is appropriately shifted up and down and 1.5 µm L & S is a dimensional change rate of ± 10% is expressed in µm.

(Resolution evaluation)

It is shown by the limit resolution in the said exposure amount Eop.

(Heat resistance evaluation)

In the above Eop exposure amount, the substrate on which 3.0 µm L & S was drawn was allowed to stand on a hot plate set at 140 ° C for 300 seconds, and then the cross-sectional shape was observed. As a result, the dimension change rate of 3.0 micrometers L & S was less than +/- 3%, and the thing in B, more than +4% in the range of 3-4% or -3-4% was represented by C.

The resist composition containing the novolak resin synthesize | combined using the specific mixed phenols of Examples 1-4 was excellent in heat resistance and a sensitivity. Moreover, it is clear that it is excellent also in characteristics, such as linearity, DOF, and resolution, and is a suitable material for system LCD manufacture. Moreover, when Examples 1-3 and Example 4 using the novolak resin synthesize | combined using specific mixed aldehydes as a aldehyde were synthesize | combined, it turns out that the resist composition which improved heat resistance was obtained further by using mixed aldehydes. have.

On the other hand, the resist compositions of Comparative Examples 1 and 2 that did not use mixed phenols were inferior in heat resistance and sensitivity.

As described above, the positive resist composition of the present invention has high sensitivity, high heat resistance, and is suitable for system LCD production.

Claims (7)

(A) Positive type photoresist composition containing alkali-soluble resin and (B) quinonediazide group containing compound, Comprising: The said (A) component is following General formula (I):

[Wherein, R represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an allyl group or an aryl group; a represents an integer of 2 to 4; b represents 0 or an integer of 1 to 2 Phenol compound (a1) represented by], and the following general formula (II):

Containing a phenol compound (a2) represented by [wherein R represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, an allyl group or an aryl group; c represents an integer of 1 to 3] Novolak resin synthesized by condensation reaction of mixed phenols and aldehydes, the polystyrene reduced mass average molecular weight is 3000-100000, positive type, characterized in that for manufacturing LCD with integrated circuit and liquid crystal display part formed on one substrate Photoresist composition. The positive type photoresist composition of Claim 1 whose compounding ratio of the said phenol compound (a1) and the said phenol compound (a2) is 1: 99-50: 50 (molar ratio). The positive type photoresist composition of claim 1, wherein the aldehydes are a mixture of formaldehyde and propionaldehyde. The positive type according to claim 1, wherein the component (B) contains an esterification reaction product of a non-benzophenone-based phenolic hydroxyl group-containing compound with 1,2-naphthoquinone diazidesulfonyl compound. Photoresist composition. The positive type photoresist composition according to claim 1, further comprising (C) a phenolic hydroxyl group-containing compound having a molecular weight of 1000 or less. (1) applying the positive photoresist composition according to any one of claims 1 to 5 onto a substrate to form a coating film; and (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 micrometers are drawn with respect to the said resist film. (4) heat-treating (post-exposure-baking) the resist film after the selective exposure; (5) developing treatment using an aqueous alkali solution to the resist film after the heat treatment, and having a pattern dimension of 2.0 μm or less on the substrate. Resist pattern for integrated circuits and resist pattern for liquid crystal display portions larger than 2.0 mu m The method of forming a resist pattern comprising the steps of. The method of forming a resist pattern according to claim 6, 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.

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