JP2021152557A - Phenolic hydroxy group-containing resin and resist material including the same - Google Patents

Abstract

To provide a phenolic resin composition and a positive resist composition having excellent sensitivity, resolution, and heat resistance.SOLUTION: According to a discovery by the inventors, the problem is solved by isolating and purifying a phenolic compound including a carboxylic acid-containing phenolic trinuclear compound and then reacting with an aliphatic aldehyde.SELECTED DRAWING: None

Description

The present invention relates to a phenolic hydroxyl group-containing resin and a resist material using the same.

Positive photoresists using alkali-soluble resins and photosensitizers such as 1,2-naphthoquinonediazide compounds are used as resists used in the manufacture of semiconductors such as ICs and LSIs, the manufacture of display devices such as LCDs, and the manufacture of printing master plates. Are known. As the alkali-soluble resin, a positive photoresist composition using a mixture of m-cresol novolak resin and p-cresol novolak resin as the alkali-soluble resin has been proposed (see, for example, Patent Document 1).

The positive photoresist composition described in Patent Document 1 was developed for the purpose of improving developability such as sensitivity, but in recent years, the high integration of semiconductors has increased, and the pattern tends to be thinner. , There is a demand for better sensitivity. However, the positive photoresist composition described in Patent Document 1 has a problem that sufficient sensitivity corresponding to thinning cannot be obtained. Further, since various heat treatments are performed in the manufacturing process of semiconductors and the like, higher heat resistance is also required, but the positive photoresist composition described in Patent Document 1 has sufficient heat resistance. There was no problem.

Further, as a substance having excellent sensitivity and high heat resistance, after reacting p-cresol or the like with an aromatic aldehyde, phenols and formaldehyde are subsequently added and reacted under an acidic catalyst. The obtained phenol resin for photoresist has been proposed (see, for example, Patent Document 2). Although this phenolic resin for photoresist has improved heat resistance as compared with the conventional one, it has not been able to sufficiently meet the recent demand for high heat resistance.

Patent Document 3 proposes a resist composition containing a novolak resin using a mixture of m-cresol, p-cresol, xylenol / trimethylphenol and a mixture of formaldehyde and aromatic aldehyde.

Patent Document 4 proposes a resist composition containing a novolak resin using a mixture of 2,3-xylenol and cresol, formaldehyde, and an aromatic aldehyde mixture containing two or more OH groups. However, even the positive photoresist composition described in Patent Document 4 has not been able to sufficiently meet the recent demand for high heat resistance.

The novolak resin has been conventionally produced by various methods, and for example, a method of reacting phenols and aldehydes in ethanol in the presence of an acid catalyst is known (see, for example, Patent Document 5). .. However, the method described in Patent Document 5 cannot obtain a high molecular weight novolak type phenol resin, and therefore, it is difficult to obtain a photoresist composition which is a coating film having higher heat resistance. ..

Patent Document 6 proposes a resist composition containing a product of a mixture of o-cresol, 2,5-dimethylphenol, and 3,5-dimethylphenol and aldehydes.

Patent Document 7 proposes a resist composition containing an acid-dissociating group-introduced novolak resin and an organic carboxylic acid.

On the other hand, in the manufacture of patterned structures, such as wafer level packaging, electrochemical deposition of electronic wiring is used as the wiring density increases. For example, refer to Solid-state, Electrochemically Deposited Solder Bumps for Wafer-Level Packaging, Packaging / Assembly, Solid State Technology (Non-Patent Document 1). Gold bumps, copper posts and copper wires for relocation in wafer level packaging require a resist mold that will be electroplated later to form the final metal structure in advanced wiring technology. .. This resist layer is very thick compared to the photoresist used in the IC production of critical layers. Both the size of the figure and the resist thickness are typically between 2 μm and 100 μm, so a high aspect ratio (resist thickness relative to line size) needs to be patterned on the photoresist.

One solution is to use an aliphatic polyaldehyde as a nodule for metacresol or paracresol when synthesizing novolak resin, which has important properties as a thick film resist, such as heat resistance and alkali dissolution rate. It was difficult to achieve both.

Japanese Unexamined Patent Publication No. 2-55359 Japanese Unexamined Patent Publication No. 2008-88197 JP-A-2002-107925 Japanese Unexamined Patent Publication No. 9-73169 Japanese Unexamined Patent Publication No. 8-286370 Japanese Unexamined Patent Publication No. 3-294861 Japanese Unexamined Patent Publication No. 9-6003

Solid State, Electrochemically Deposited Solder Bumps for Wafer-Level Packaging, Packaging / Assembly, Solid State Technology

An object of the present invention is to provide a phenol resin composition and a positive resist composition having excellent sensitivity, excellent resolution, and excellent heat resistance.

As a result of diligent studies, the present inventors have found that the above problems can be solved by isolating and purifying a phenolic compound containing a carboxylic acid-containing phenolic trinuclear compound and reacting it with an aliphatic aldehyde. The invention was completed.

That is, the present invention relates to the following (1) to (9).
(1) A positive type containing a novolak type phenol resin (C) obtained by condensing an aromatic compound (A) represented by the following formula (1) and an aliphatic aldehyde (B). Photoresist composition.

（式中、Ｒ_１、Ｒ_２はそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基、ハロゲン原子を表し、Ｒ_３、Ｒはそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基又は炭化水素基上にアルコキシ基、ハロゲン基、水酸基を一つ乃至複数有する構造部位を表し、ｍ、ｎはそれぞれ独立して０又は１〜４の整数を表す。）
（２）前記脂肪族アルデヒド（Ｂ）が、ホルムアルデヒド及び／またはパラホルムアルデヒドである、（１）に記載のポジ型フォトレジスト組成物。
（３）前記芳香族化合物（Ａ）が、フェノール化合物と、カルボキシル基もしくはそのエステル誘導体を有する芳香族アルデヒドおよび／またはカルボキシル基もしくはそのエステル誘導体を有する芳香族ケトンとを重縮合したものである、（１）または（２）に記載のポジ型フォトレジスト組成物。
（４）前記カルボキシル基を有する芳香族アルデヒドが、ホルミル安息香酸である、（３）に記載のポジ型フォトレジスト組成物。
（５）前記芳香族化合物（Ａ）が、単離精製された後に脂肪族アルデヒド（Ｂ）との縮合に用いられたものである、（１）から（４）のいずれか一項に記載のポジ型フォトレジスト組成物。
（６）下記式（１）で表される芳香族化合物（Ａ）を単離精製し、次いで脂肪族アルデヒド（Ｂ）と縮合させてノボラック型フェノール樹脂（Ｃ）を得ることを特徴とする、ポジ型フォトレジスト組成物の製造方法。

(In the formula, R ₁ and R ₂ independently represent H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, and a halogen atom, and R ₃ and R are independent of each other. Represents a structural site having one or more alkoxy groups, halogen groups, and hydroxyl groups on H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms or a hydrocarbon group, and m and n are independently 0 or 0, respectively. Represents an integer of 1 to 4)
(2) The positive photoresist composition according to (1), wherein the aliphatic aldehyde (B) is formaldehyde and / or paraformaldehyde.
(3) The aromatic compound (A) is obtained by polycondensing a phenol compound with an aromatic aldehyde having a carboxyl group or an ester derivative thereof and / or an aromatic ketone having a carboxyl group or an ester derivative thereof. The positive type photoresist composition according to (1) or (2).
(4) The positive photoresist composition according to (3), wherein the aromatic aldehyde having a carboxyl group is formylbenzoic acid.
(5) The item according to any one of (1) to (4), wherein the aromatic compound (A) is used for condensation with an aliphatic aldehyde (B) after being isolated and purified. Positive photoresist composition.
(6) The aromatic compound (A) represented by the following formula (1) is isolated and purified, and then condensed with an aliphatic aldehyde (B) to obtain a novolak type phenol resin (C). A method for producing a positive photoresist composition.

（式中、Ｒ_１、Ｒ_２はそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基、ハロゲン原子を表し、Ｒ_３、Ｒはそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基又は炭化水素基上にアルコキシ基、ハロゲン基、水酸基を一つ乃至複数有する構造部位を表し、ｍ、ｎはそれぞれ独立して０又は１〜４の整数を表す。）
（７）前記脂肪族アルデヒド（Ｂ）が、ホルムアルデヒド及び／またはパラホルムアルデヒドである、（６）に記載のポジ型フォトレジスト組成物の製造方法。
（８）前記芳香族化合物（Ａ）が、フェノール化合物と、カルボキシル基もしくはそのエステル誘導体を有する芳香族アルデヒドおよび／またはカルボキシル基もしくはそのエステル誘導体を有する芳香族ケトンとを重縮合したものである、（６）または（７）に記載のポジ型フォトレジスト組成物の製造方法。
（９）前記カルボキシル基を有する芳香族アルデヒドが、ホルミル安息香酸である、（８）に記載のポジ型フォトレジスト組成物の製造方法。

(In the formula, R ₁ and R ₂ independently represent H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, and a halogen atom, and R ₃ and R are independent of each other. Represents a structural site having one or more alkoxy groups, halogen groups, and hydroxyl groups on H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms or a hydrocarbon group, and m and n are independently 0 or 0, respectively. Represents an integer of 1 to 4)
(7) The method for producing a positive photoresist composition according to (6), wherein the aliphatic aldehyde (B) is formaldehyde and / or paraformaldehyde.
(8) The aromatic compound (A) is obtained by polycondensing a phenol compound with an aromatic aldehyde having a carboxyl group or an ester derivative thereof and / or an aromatic ketone having a carboxyl group or an ester derivative thereof. The method for producing a positive photoresist composition according to (6) or (7).
(9) The method for producing a positive photoresist composition according to (8), wherein the aromatic aldehyde having a carboxyl group is formylbenzoic acid.

According to the present invention, it is possible to provide a phenol resin composition and a positive resist composition having excellent sensitivity, excellent resolution, and excellent heat resistance. Further, the composition of the present invention has high contrast characteristics (a large difference in ADR (Alkali Dissolution Rate, alkali dissolution rate) before and after the addition of the photosensitizer), but is compatible with general novolak for resist (m-, p-cresol, formalin). Heat resistance is dramatically higher than that of (polymerization).

It is a figure which shows the GPC chart of the precursor compound (1) in the Example described later. It is a figure which shows the 1H-NMR chart of the precursor compound (1) in the Example described later. It is a figure which shows the GPC chart of the precursor compound (2) in the Example described later. It is a figure which shows the 13C-NMR chart of the precursor compound (2) in the Example described later. It is a figure which shows the GPC chart of the novolak resin (A) in the Example described later. It is a figure which shows the GPC chart of the novolak resin (B) in the Example described later. It is a figure which shows the GPC chart of the novolak resin (C) in the Example described later. It is a figure which shows the GPC chart of the novolak resin (D) in the Example described later. It is a figure which shows the GPC chart of the novolak resin (E) in the comparative example described later. It is a figure which shows the GPC chart of the novolak resin (F) in the comparative example described later.

Hereinafter, one embodiment of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications as long as the effects of the present invention are not impaired.

[Positive photoresist composition]
The positive photoresist composition of the present invention contains a novolak-type phenol resin (C) obtained by condensing an aromatic compound (A) represented by the following formula (1) and an aliphatic aldehyde (B). It is characterized by that.

（式中、Ｒ_１、Ｒ_２はそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基、ハロゲン原子を表し、Ｒ_３、Ｒはそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基又は炭化水素基上にアルコキシ基、ハロゲン基、水酸基を一つ乃至複数有する構造部位を表し、ｍ、ｎはそれぞれ独立して０又は１〜４の整数を表す。）

(In the formula, R ₁ and R ₂ independently represent H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, and a halogen atom, and R ₃ and R are independent of each other. Represents a structural site having one or more alkoxy groups, halogen groups, and hydroxyl groups on H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms or a hydrocarbon group, and m and n are independently 0 or 0, respectively. Represents an integer of 1 to 4)

[Aromatic compound (A)]
The aromatic compound (A) is, for example, an alkyl-substituted phenol (a1), an aromatic aldehyde (a2) having a carboxyl group or an ester derivative thereof, and / or an aromatic ketone (a3) having a carboxyl group or an ester derivative thereof. Can be obtained by polycondensing with.

(Alkyl Substituted Phenol (a1))
The alkyl-substituted phenol (a1) is a compound in which a part or all of hydrogen atoms bonded to the aromatic ring of phenol are substituted with alkyl groups. Examples of the alkyl group include an alkyl group having 1 to 8 carbon atoms, and a methyl group is particularly preferable. Examples of the alkyl-substituted phenol (a1) include o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, p-octylphenol, pt-butylphenol, o. Monoalkylphenols such as −cyclohexylphenol, m-cyclohexylphenol, and p-cyclohexylphenol; Alkylphenol; examples thereof include trialkylphenols such as 2,3,5-trimethylphenol and 2,3,6-trimethylphenol. Further, among these alkyl-substituted phenols, those having an alkyl group substitution number of 2 in the aromatic ring of the phenol are preferable because they have an excellent balance between heat resistance and alkali solubility, and as a specific example, 2,5-xylenol. , 2,6-xylenol and the like. These alkyl-substituted phenols (a1) can be used alone or in combination of two or more.

(Aromatic aldehyde (a2))
The aromatic aldehyde (a2) is a compound having at least one carboxyl group or an ester derivative thereof and an aldehyde group on the aromatic ring. Examples of the aromatic aldehyde (a2) include 4-formylbenzoic acid, 2-formylbenzoic acid, 3-formylbenzoic acid, and methyl 4-formylbenzoate, ethyl 4-formylbenzoate, and 4-formylbenzoic acid. Representatives of propyl, isopropyl 4-formylbenzoate, butyl 4-formylbenzoate, isobutyl 4-formylbenzoate, tertiary butyl 4-formylbenzoate, cyclohexyl 4-formylbenzoate, tertiary octyl 4-formylbenzoate, etc. These include, but are not limited to, ester derivatives. Among these aromatic aldehydes (a2), 4-formylbenzoic acid is preferable because it is easily available industrially and has an excellent balance between heat resistance and alkali solubility. These aromatic aldehydes (a2) may be used alone or in combination of two or more.

(Aromatic ketone (a3))
The aromatic ketone (a3) is a compound having at least one carboxyl group or an ester derivative thereof and a carbonyl group on the aromatic ring. Examples of the aromatic ketone (a3) include 2-acetylbenzoic acid, 3-acetylbenzoic acid, 4-acetylbenzoic acid, and methyl 2-acetylbenzoate, ethyl 2-acetylbenzoate, and 2-acetylbenzoic acid. Representatives of propyl, isopropyl 2-acetylbenzoate, butyl 2-acetylbenzoate, isobutyl 2-acetylbenzoate, tertiary butyl 2-acetylbenzoate, cyclohexyl 2-acetylbenzoate, tertiary octyl 2-acetylbenzoate, etc. These include, but are not limited to, ester derivatives. Further, among these aromatic ketones (a3), 2-acetylbenzoic acid and 4-acetylbenzoic acid are preferable because they are easily available industrially and have an excellent balance between heat resistance and alkali solubility. These aromatic ketones (a3) may be used alone or in combination of two or more.

[Aliphatic aldehyde (B)]
Examples of the aliphatic aldehyde (B) include formaldehyde, paraformaldehyde, 1,3,5-trioxane, acetaldehyde, propionaldehyde, tetraoxymethylene, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glioxal, and n-. Examples thereof include butylaldehyde, caproaldehyde, allylaldehyde, crotonaldehyde, achlorine and the like. These aldehyde compounds (B) can be used alone or in combination of two or more. Further, it is preferable to use formaldehyde as the aliphatic aldehyde (B), and formaldehyde and other aliphatic aldehydes may be used in combination. When formaldehyde and other aliphatic aldehydes are used in combination, the amount of other aliphatic aldehydes used is preferably in the range of 0.05 to 1 mol with respect to 1 mol of formaldehyde.

[Novolak type phenol resin (C)]
Examples of the method for producing the novolak-type phenol resin (C), which is a constituent component of the positive photoresist composition of the present invention, include a method through the following three steps.

(Step 1)
The alkyl-substituted phenol (a1) and the aromatic aldehyde (a2) are heated in the range of 60 to 140 ° C. in the presence of an acid catalyst, if necessary, using a solvent, and polycondensed to obtain the aromatic. Obtain the group compound (A).

(Step 2)
The aromatic compound (A) obtained in step 1 is isolated from the reaction solution.

(Step 3)
The aromatic compound (A) and the aliphatic aldehyde (B) isolated in step 2 are heated in the range of 60 to 140 ° C. in the presence of an acid catalyst, if necessary, using a solvent, and polycondensed. By doing so, a novolak-type phenol resin (C), which is a constituent component of the positive photoresist composition of the present invention, is obtained.

Examples of the acid catalyst used in steps 1 and 3 include acetic acid, oxalic acid, sulfuric acid, hydrochloric acid, phenol sulfonic acid, paratoluene sulfonic acid, zinc acetate, manganese acetate and the like. These acid catalysts may be used alone or in combination of two or more. Among these acid catalysts, sulfuric acid and paratoluenesulfonic acid are preferable in step 1, and sulfuric acid, oxalic acid and zinc acetate are preferable in step 3 from the viewpoint of excellent activity. The acid catalyst may be added before the reaction or during the reaction.

Examples of the solvent used in steps 1 and 3 as necessary include monoalcohols such as methanol, ethanol, and propanol; ethylene glycol, 1,2-propanediol, 1,3-propanediol, and 1,4-butane. Polycols such as diols, 1,5-pentanediols, 1,6-hexanediols, 1,7-heptanediols, 1,8-octanediols, 1,9-nonanediols, trimethylene glycols, diethylene glycols, polyethylene glycols and glycerins. 2-ethoxyethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol monophenyl ether, etc. Glycol ethers; cyclic ethers such as 1,3-dioxane and 1,4-dioxane; glycol esters such as ethylene glycol acetate; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene Can be mentioned. These solvents may be used alone or in combination of two or more. Further, among these solvents, 2-ethoxyethanol is preferable from the viewpoint of excellent solubility of the obtained compound.

The charging ratio [(a1) / (a2)] of the alkyl-substituted phenol (a1) and the aromatic aldehyde (a2) in step 1 is the removability of the unreacted alkyl-substituted phenol (a1) and the product. Since the yield and the purity of the reaction product are excellent, the molar ratio is preferably in the range of 1 / 0.2 to 1 / 0.5, and more preferably in the range of 1 / 0.25 to 1 / 0.45.

The charging ratio [(A) / (B)] of the aromatic compound (A) and the aliphatic aldehyde (B) in step 3 can suppress excessive high molecular weight (gelation), and is a phenol for photoresist. Since a resin having an appropriate molecular weight can be obtained, the molar ratio is preferably in the range of 1 / 0.5 to 1 / 1.2, more preferably in the range of 1 / 0.6 to 1 / 0.9.

As a method for isolating the aromatic compound (A) from the reaction solution in step 2, for example, a precipitate obtained by putting the reaction solution into a poor solvent (S1) in which the reaction product is insoluble or sparingly soluble. A method is to filter out the product, dissolve the reaction product in a solvent (S2) that is also compatible with the poor solvent (S1), and then put the reaction product into the poor solvent (S1) again to filter out the resulting precipitate. Can be mentioned. Examples of the poor solvent (S1) used in this case include water; monoalcohols such as methanol, ethanol and propanol; aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane and cyclohexane; toluene and xylene. Such as aromatic hydrocarbons. Among these poor solvents (S1), water and methanol are preferable because the acid catalyst can be efficiently removed at the same time. On the other hand, examples of the solvent (S2) include monoalcohols such as methanol, ethanol and propanol; ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol and 1,5-. Polyols such as pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, glycerin; 2-ethoxyethanol, Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol monophenyl ether; 1, Cyclic ethers such as 3-dioxane and 1,4-dioxane; glycol esters such as ethylene glycol acetate; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone can be mentioned. When water is used as the poor solvent (S1), acetone is preferable as the (S2). The poor solvent (S1) and the solvent (S2) may be used alone or in combination of two or more.

When aromatic hydrocarbons such as toluene and xylene are used as the solvent in steps 1 and 3, the aromatic compound (A) produced by the reaction dissolves in the solvent when heated at 80 ° C. or higher. Therefore, the crystals of the aromatic compound (A) are precipitated by cooling as it is, and the aromatic compound (A) can be isolated by filtering the crystals. In this case, it is not necessary to use the poor solvent (S1) and the solvent (S2).

By the isolation method of the above step 2, the aromatic compound (A) represented by the following general formula (1) can be obtained.

（式中、Ｒ_１、Ｒ_２はそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基、ハロゲン原子を表し、Ｒ_３、Ｒはそれぞれ独立してＨまたは炭素原子数１〜９の脂肪族炭化水素基又は炭化水素基上にアルコキシ基、ハロゲン基、水酸基を一つ乃至複数有する構造部位を表し、ｍ、ｎはそれぞれ独立して０又は１〜４の整数を表す。）

(In the formula, R ₁ and R ₂ independently represent H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, and a halogen atom, and R ₃ and R are independent of each other. Represents a structural site having one or more alkoxy groups, halogen groups, and hydroxyl groups on H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms or a hydrocarbon group, and m and n are independently 0 or 0, respectively. Represents an integer of 1 to 4)

The weight average molecular weight (Mw) of the novolak type phenol resin (C) obtained by the above production method is preferably in the range of 2,000 to 35,000, more preferably in the range of 2,000 to 25,000. This weight average molecular weight (Mw) was measured under the following measurement conditions using gel permeation chromatography (hereinafter abbreviated as "GPC").

(GPC measurement conditions)
Measuring device: "HLC-8220 GPC" manufactured by Tosoh Corporation
Column: "Shodex KF802" manufactured by Showa Denko KK (8.0 mm Ф x 300 mm)
+ "Shodex KF802" manufactured by Showa Denko KK (8.0 mm Ф x 300 mm)
+ "Shodex KF803" manufactured by Showa Denko KK (8.0 mm Ф x 300 mm)
+ "Shodex KF804" manufactured by Showa Denko KK (8.0 mm Ф x 300 mm)
Column temperature: 40 ° C
Detector: RI (Differential Refractometer)
Data processing: "GPC-8020 Model II Version 4.30" manufactured by Tosoh Corporation
Developing solvent: Tetrahydrofuran Flow velocity: 1.0 mL / min Sample: Tetrahydrofuran solution of 0.5% by mass in terms of resin solid content filtered through a microfilter (100 μl)
Standard sample: The following monodisperse polystyrene

(Standard sample: monodisperse polystyrene)
"A-500" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation

In the positive photoresist composition of the present invention, the novolak-type phenol resin (C) obtained by the above production method is a constituent component as an alkali-soluble resin, but another alkali-soluble resin (D) may be used in combination. No.

The alkali-soluble resin (D) may be any resin that is soluble in an aqueous alkaline solution, and cresol novolac resin is particularly preferable. The cresol novolak resin is a novolak-type phenol resin obtained by condensing a phenol-based compound and an aldehyde compound as raw materials, and is at least one phenol-based resin selected from the group consisting of o-cresol, m-cresol and p-cresol. It is manufactured using a compound as an essential raw material.

As the phenolic compound used as the raw material of the cresol novolak resin, o-cresol, m-cresol or p-cresol is indispensable, but other phenols or derivatives thereof may be used in combination. Examples of such phenol or derivatives thereof include phenol; 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol and the like. Xylenol; ethylphenol such as o-ethylphenol, m-ethylphenol, p-ethylphenol; butylphenol such as isopropylphenol, butylphenol, pt-butylphenol; p-pentylphenol, p-octylphenol, p-nonylphenol, p. -Alkylphenol such as cumylphenol; Halogenated phenol such as fluorophenol, chlorophenol, bromophenol, iodophenol; mono-substituted phenol such as p-phenylphenol, aminophenol, nitrophenol, dinitrophenol, trinitrophenol; 1- Condensed polycyclic phenols such as naphthol and 2-naphthol; polyhydric phenols such as resorcin, alkylresorcin, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, fluoroglucin, bisphenol A, bisphenol F, bisphenol S, dihydroxynaphthalin, etc. Can be mentioned. These other phenols or derivatives thereof may be used alone or in combination of two or more. When other phenols or derivatives thereof are used in combination, the amount of other phenols or derivatives used is 0.05 to 1 mol with respect to 1 mol of the total cresol of o-cresol, m-cresol and p-cresol. It is preferable that the range is.

Examples of the aldehyde compound used as a raw material for the cresol novolak resin include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxymethylene, chloral, hexamethylenetetramine, furfural, glioxal, n-butylaldehyde, and capro. Examples thereof include aldehyde, allyl aldehyde, benzaldehyde, croton aldehyde, achlorine, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde and the like. These aldehyde compounds may be used alone or in combination of two or more. Further, it is preferable to use formaldehyde as a raw material of the cresol novolak resin, and formaldehyde and other aldehyde compounds may be used in combination. When formaldehyde and other aldehyde compounds are used in combination, the amount of the other aldehyde compound used is preferably in the range of 0.05 to 1 mol with respect to 1 mol of formaldehyde.

The condensation reaction of the phenolic compound and the aldehyde compound is preferably carried out in the presence of an acid catalyst. Examples of the acid catalyst include oxalic acid, sulfuric acid, hydrochloric acid, phenol sulfonic acid, paratoluene sulfonic acid, zinc acetate, manganese acetate and the like. These acid catalysts may be used alone or in combination of two or more. Among these acid catalysts, oxalic acid is preferable because it has excellent catalytic activity. The acid catalyst may be added before the reaction or during the reaction.

Further, the molar ratio [(F) / (P)] of the phenolic compound (P) to the aldehyde compound (F) in producing the cresol novolak resin is excellent in sensitivity and heat resistance. The range of 0.3 to 1.6 is preferable, and the range of 0.5 to 1.3 is more preferable.

As a more specific method for producing the cresol novolak resin, a phenolic compound, an aldehyde compound and an acid catalyst are heated to 60 to 140 ° C. to allow a polycondensation reaction to proceed, and then dehydration and demonomerization are carried out under reduced pressure conditions. There is a way to do it.

The positive photoresist composition of the present invention usually contains a photosensitizer (E) and a solvent (F) in addition to the above-mentioned novolak-type phenol resin (C) and an optionally blended alkali-soluble resin (D). ..

As the photosensitizer (E), a compound having a quinonediazide group can be used. Examples of the compound having a quinone diazide group include 2,3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, and 2,3,6-trihydroxy. Benzophenone, 2,3,4-trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,3', 4 , 4', 6-pentahydroxybenzophenone, 2,2', 3,4,4'-pentahydroxybenzophenone, 2,2', 3,4,5-pentahydroxybenzophenone, 2,3', 4,4' , 5', 6-hexahydroxybenzophenone, 2,3,3', 4,4', 5'-hexahydroxybenzophenone and other polyhydroxybenzophenone compounds; bis (2,4-dihydroxyphenyl) methane, bis (2) , 3,4-Trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2', 4' -Dihydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (2', 3', 4'-trihydroxyphenyl) propane, 4,4'-{1- [4-[ 2- (4-Hydroxyphenyl) -2-propyl] phenyl] ethylidene} bisphenol, 3,3'-dimethyl- {1- [4- [2- (3-methyl-4-hydroxyphenyl) -2-propyl] Bis [(poly) hydroxyphenyl] alcan compounds such as phenyl] ethylidene} bisphenol; tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis ( 4-Hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) ) -2-Hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenyl Tris (hydroxyphenyl) methanes such as methane or methyl substituents thereof; bis (3-cyclohexyl-4-hydroxyphenyl) ) -3-Hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-) 4-Hydroxy-2-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-) Methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -4-hydroxyphenylmethane, Bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-) 2-Hydroxyphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -2-hydroxyphenyl Bis (cyclohexylhydroxyphenyl) (hydroxyphenyl) methanes such as methane and bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -4-hydroxyphenylmethane or methyl substituents thereof and naphthoquinone-1,2 -Complete ester compound, partial ester compound, amidate or partial amidate with sulfonic acid having a quinone diazide group such as diazido-5-sulfonic acid or naphthoquinone-1,2-diazide-4-sulfonic acid, orthoanthraquinone diazidosulfonic acid. And so on. These photosensitizers (E) may be used alone or in combination of two or more.

The amount of the photosensitizer (E) in the positive photoresist composition of the present invention is such that good sensitivity can be obtained and a desired pattern can be obtained. Therefore, the novolak-type phenol resin (C) and the alkali-soluble resin can be obtained. The range of 3 to 50 parts by mass is preferable, and the range of 5 to 30 parts by mass is more preferable with respect to the total of 100 parts by mass of (D).

Examples of the solvent (F) include ethylene glycol alkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dipropyl ether. Diethylene glycol dialkyl ethers such as diethylene glycol dibutyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; propylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and propylene glycol monopropyl ether acetate. Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl amyl ketone; cyclic ethers such as dioxane; methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, Ethers such as ethyl oxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl formate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate, etc. Can be mentioned. These solvents (F) can be used alone or in combination of two or more.

The amount of the solvent (F) blended in the positive photoresist composition of the present invention is such that the fluidity of the composition can be uniformly coated by a coating method such as a spin coating method, so that the solid in the composition can be obtained. The amount is preferably such that the component concentration is 15 to 65% by mass.

The positive photoresist composition of the present invention includes the novolak-type phenol resin (C), another alkali-soluble resin (D) optionally blended, a photosensitizer (E) and a solvent (F), as well as the present invention. Various additives may be blended as long as the effect is not impaired. Examples of such additives include fillers, pigments, surfactants such as leveling agents, adhesion improvers, dissolution accelerators and the like.

The positive photoresist composition of the present invention is added to the novolak-type phenol resin (C), another alkali-soluble resin (D) optionally blended, a photosensitizer (E) and a solvent (F), and if necessary. It can be prepared by stirring and mixing the various additives by a usual method to obtain a uniform liquid.

Further, when a solid material such as a filler and a pigment is blended in the positive photoresist composition of the present invention, it is preferable to disperse and mix using a disperser such as a dissolver, a homogenizer, or a three-roll mill. Further, in order to remove coarse particles and impurities, the composition can be filtered using a mesh filter, a membrane filter or the like.

When the positive photoresist composition of the present invention is exposed through a mask, the resin composition undergoes a structural change in the exposed portion, and its solubility in an alkaline developer is promoted. On the other hand, since the non-exposed portion retains low solubility in an alkaline developer, this difference in solubility enables patterning by alkaline development and can be used as a resist material.

Examples of the light source for exposing the positive photoresist composition of the present invention include infrared light, visible light, ultraviolet light, far ultraviolet light, X-rays, and electron beams. Among these light sources, ultraviolet light is preferable, and g-line (wavelength 436 nm), i-line (wavelength 365 nm), and EUV laser (wavelength 13.5 nm) of a high-pressure mercury lamp are preferable.

Examples of the alkaline developing solution used for post-exposure development include inorganic alkaline substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; ethylamine, n-propylamine, and the like. Primary amines; Secondary amines such as diethylamine and di-n-butylamine; Tertiary amines such as triethylamine and methyldiethylamine; Alkaline amines such as dimethylethanolamine and triethanolamine; Tetramethylammonium hydroxide, tetraethyl A quaternary ammonium salt such as ammonium hydroxide; an alkaline aqueous solution such as a cyclic amine such as pyrrole or pihelidine can be used. Alcohol, a surfactant and the like can be appropriately added to these alkaline developers, if necessary. The alkali concentration of the alkaline developer is usually preferably in the range of 2 to 5% by mass, and a 2.38% by mass tetramethylammonium hydroxide aqueous solution is generally used.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Preparation of resist solution>
The synthesized novolak resin and propylene glycol monomethyl ether acetate (PGMEA) were mixed and dissolved at 20/75 (part by weight), and microfiltered with a 0.1 μm PTFE disc filter to obtain a resist composition.

<Evaluation of alkali developability>
The resist composition was applied on a 5-inch silicon wafer with a spin coater to a thickness of about 1 μm, and dried on a hot plate at 110 ° C. for 60 seconds. The obtained wafer was immersed in a developing solution (2.38% aqueous solution of tetramethylammonium hydroxide) for 60 seconds, and then dried on a hot plate at 110 ° C. for 60 seconds. The film thickness before and after immersion in the developing solution was measured, and the value obtained by dividing the difference by 60 was defined as alkali developability (ADR1 (Å / s)).
Further, using a resist composition prepared by using a photosensitizer (P-200 manufactured by Toyo Gosei Co., Ltd.) used as a photoresist as a novolac resin / P-200 / PGMEA = 20/5/75 (part by weight). The value measured in the same manner was defined as (ADR2 (Å / s)).
Similarly, the values measured with and without a photosensitizer using a 15% sodium carbonate aqueous solution as a developing solution were defined as alkali developability (ADR3 (Å / s)) and alkali developability (ADR4 (Å / s)).

<Heat resistance evaluation>
The resist permanent film material was applied onto a silicon wafer having a diameter of 5 inches using a spin coater, and then dried at 110 ° C. for 60 seconds to obtain a thin film having a thickness of 1 μm. This thin film was scraped off and the glass transition temperature (hereinafter abbreviated as "Tg") was measured. The Tg is measured using a differential thermal scanning calorimeter (“Differential Thermal Scanning Calorimeter (DSC) Q100” manufactured by TA Instruments Co., Ltd.) in a temperature range of -100 to 200 ° C. under a nitrogen atmosphere. , The temperature rising rate was 10 ° C./min. The evaluation criteria are as follows.
◯: Tg is 150 ° C. or higher ×: Tg is 150 ° C. or lower

<Carboxylic acid-containing phenolic trinuclear: Synthesis of precursor compound (1)>
(Manufacturing Example 1)
293.2 g (2.4 mol) of 2,5-xylenol and 150 g (1 mol) of 4-formylbenzoic acid were placed in a 2000 ml 4-neck flask equipped with a cooling tube and dissolved in 500 ml of 2-ethoxyethanol. After adding 10 ml of sulfuric acid while cooling in an ice bath, the mixture was heated at 100 ° C. for 2 hours with a mantle heater and stirred to react. After the reaction, the obtained solution was reprecipitated with water to obtain a crude product. The crude product was redissolved in acetone and further subjected to a reprecipitation operation with water, and then the obtained product was filtered off and vacuum dried to obtain 292 g of a pale pink crystal precursor compound (1). .. The GPC purity was 95.3%, and it was confirmed by 1H-NMR that it was the target compound. The GPC chart of the precursor compound (1) is shown in FIG. 1, and the 1H-NMR chart is shown in FIG.

<Phenolic nucleosome: Synthesis of precursor compound (2)>
(Manufacturing Example 2)
293.2 g (2.4 mol) of 2,5-xylenol and 122 g (1 mol) of 2-hydroxybenzaldehyde were placed in a 2000 ml 4-neck flask provided with a cooling tube and dissolved in 500 ml of 2-ethoxyethanol. After adding 10 ml of sulfuric acid while cooling in an ice bath, the mixture was heated at 100 ° C. for 2 hours with a mantle heater and stirred to react. After the reaction, the obtained solution was reprecipitated with water to obtain a crude product. The crude product was redissolved in acetone and further subjected to a reprecipitation operation with water, and then the obtained product was filtered off and vacuum dried to obtain 213 g of a precursor compound (2) of white crystals. The GPC purity was 98.2%, and it was confirmed by 13C-NMR that it was the target compound. The GPC chart of the precursor compound (2) is shown in FIG. 3, and the 13C-NMR chart is shown in FIG.

[Example 1]
(Manufacturing Example 3: Synthesis of Novolac Resin (A))
18.8 g (0.05 mol) of precursor compound (1) and 1.6 g (0.05 mol) of 92% paraformaldehyde were charged in a 300 ml 4-neck flask equipped with a cooling tube, and dissolved in 15 ml of 2-ethoxyethanol and 15 ml of acetic acid. I let you. After adding 10 ml of sulfuric acid while cooling in an ice bath, the temperature was raised to 80 ° C. in an oil bath, heating for 4 hours, stirring was continued, and the reaction was carried out. After the reaction, the obtained solution was reprecipitated with water to obtain a crude product. The crude product was redissolved in acetone and further subjected to a reprecipitation operation with water, and then the obtained product was filtered off and vacuum dried to obtain 16.9 g of a pale red powder novolak resin (A). rice field. The GPC of the novolak resin (A) had a number average molecular weight (Mn) = 3331, a weight average molecular weight (Mw) = 6738, and a polydispersity (Mw / Mn) = 2.02. The GPC chart of the novolak resin (A) is shown in FIG.

[Example 2]
(Production Example 4: Synthesis of novolak resin (B), molar ratio of precursor compound (1) to precursor compound (2) 25:75)
Precursor compound (1) 4.5 g (0.012 mol), precursor compound (2) 13.2 g (0.038 mol), 92% paraformaldehyde 1.6 g (0. 05 mol) was charged and dissolved in 15 ml of 2-ethoxyethanol and 15 ml of acetic acid. After adding 10 ml of sulfuric acid while cooling in an ice bath, the temperature was raised to 80 ° C. in an oil bath, heating for 4 hours, stirring was continued, and the reaction was carried out. After the reaction, the obtained solution was reprecipitated with water to obtain a crude product. The crude product was redissolved in acetone and further subjected to a reprecipitation operation with water, and then the obtained product was filtered off and vacuum dried to obtain 17.3 g of a pale red powder novolak resin (B). The GPC of the novolak resin (B) had a number average molecular weight (Mn) = 2089, a weight average molecular weight (Mw) = 7289, and a polydispersity (Mw / Mn) = 3.49. The GPC chart of the novolak resin (B) is shown in FIG.

[Example 3]
(Production Example 5: Synthesis of novolak resin (C), molar ratio of precursor compound (1) to precursor compound (2) 50:50)
The pale red powder was prepared in the same manner as in Example 2 (Production Example 4) except that 9.4 g (0.025 mol) of the precursor compound (1) and 8.7 g (0.025 mol) of the precursor compound (2) were used. 16.8 g of novolak resin (C) was obtained. The GPC of the novolak resin (C) had a number average molecular weight (Mn) = 2253, a weight average molecular weight (Mw) = 7259, and a polydispersity (Mw / Mn) = 3.22. The GPC chart of the novolak resin (C) is shown in FIG.

[Example 4]
(Production Example 6: Synthesis of novolak resin (D), molar ratio of precursor compound (1) to precursor compound (2) 75:25)
The pale red powder was prepared in the same manner as in Example 2 (Production Example 4) except that 14.3 g (0.038 mol) of the precursor compound (1) and 4.2 g (0.012 mol) of the precursor compound (2) were used. 18.1 g of novolak resin (D) was obtained. The GPC of the novolak resin (D) had a number average molecular weight (Mn) = 2438, a weight average molecular weight (Mw) = 5613, and a polydispersity (Mw / Mn) = 2.30. The GPC chart of the novolak resin (D) is shown in FIG.

[Comparative Example 1]
(Synthetic Comparative Example 1)
In a 2L 4-neck flask equipped with a stirrer and a thermometer, 552 g (4 mol) of 2-hydroxybenzoic acid, 498 g (3 mol) of 1,4-bis (methoxymethyl) benzene, 2.5 g of p-toluenesulfonic acid, and 500 g of toluene. Was charged, the temperature was raised to 120 ° C., and a demethanol reaction was carried out. The temperature was raised and distilled under reduced pressure, and distillation was carried out under reduced pressure at 230 ° C. for 6 hours to obtain 882 g of a pale yellow solid novolak resin (E). The GPC of the novolak resin (E) had a number average molecular weight (Mn) = 1016, a weight average molecular weight (Mw) = 2782, and a polydispersity (Mw / Mn) = 2.74. The GPC chart of the novolak resin (E) is shown in FIG.

[Comparative Example 2]
(Synthetic Comparative Example 2)
In a 2L 4-neck flask equipped with a stirrer and a thermometer, 648 g (6 mol) of m-cresol, 432 g (4 mol) of p-cresol, 2.5 g (0.2 mol) of oxalic acid, and 492 g of 42% formaldehyde were charged, and the temperature was 100 ° C. The temperature was raised and reacted. It was dehydrated and distilled to 200 ° C. at normal pressure, and distilled under reduced pressure at 230 ° C. for 6 hours to obtain 736 g of a pale yellow solid novolak resin (F). The GPC of the novolak resin (F) had a number average molecular weight (Mn) = 1450, a weight average molecular weight (Mw) = 10316, and a polydispersity (Mw / Mn) = 7.116. The GPC chart of the novolak resin (F) is shown in FIG.

Table 1 shows the results of each measurement and evaluation using the positive photoresist compositions prepared from the novolak resins (A) to (F) of Examples 1 to 4 and Comparative Examples 1 and 2, respectively.

From the evaluation results shown in Table 1, the developing solution of the positive photoresist composition of the present invention prepared from the novolak resin (A) obtained in Example 1 was a 2.38% aqueous solution of tetramethylammonium hydroxide. When this was done, it was found that the positive photoresist composition containing no photosensitizer corresponding to the exposed portion had a very fast alkali dissolution rate of 15,000 Å / sec and had excellent sensitivity. (ADR1). Further, it was found that the alkali dissolution rate of the positive photoresist composition containing the photosensitizer corresponding to the unexposed portion was as low as 80 Å / sec, and the pattern remained without any problem even after alkaline development (ADR2).
Further, when the developing solution is a 15% sodium carbonate aqueous solution, the positive photoresist composition containing no photosensitive agent corresponding to the exposed portion has a very fast alkali dissolution rate of 820 Å / sec. It was found to have excellent sensitivity (ADR3). Further, it was found that the alkali dissolution rate of the positive photoresist composition containing the photosensitizer corresponding to the unexposed portion was very low, less than 1 Å / sec, and the pattern remained without problems even after alkaline development (ADR4). ..
Further, it was found that the Tg of the coating film of the positive photoresist composition was as high as 213 ° C. and the heat resistance was also excellent.

From the evaluation results shown in Table 1, the developing solution of the positive photoresist composition of the present invention prepared from the novolak resin (B) obtained in Example 2 was a 2.38% aqueous solution of tetramethylammonium hydroxide. In the case of, it was found that the positive photoresist composition containing no photosensitizer corresponding to the exposed portion had a very fast alkali dissolution rate of 6,500 Å / sec and had excellent sensitivity. (ADR1). Further, it was found that the alkali dissolution rate of the positive photoresist composition containing the photosensitizer corresponding to the unexposed portion was as low as 42 Å / sec, and the pattern remained without any problem even after alkaline development (ADR2).
Further, when the developing solution is a 15% sodium carbonate aqueous solution, the positive photoresist composition containing no photosensitive agent corresponding to the exposed portion has a very fast alkali dissolution rate of 410 Å / sec. It was found to have excellent sensitivity (ADR3). Further, it was found that the alkali dissolution rate of the positive photoresist composition containing the photosensitizer corresponding to the unexposed portion was very low, less than 1 Å / sec, and the pattern remained without problems even after alkaline development (ADR4). ..
Further, it was found that the Tg of the coating film of the positive photoresist composition was as high as 186 ° C., and the heat resistance was also excellent.

Similarly, as shown in Table 1, for the positive photoresist composition of the present invention prepared from the novolak resin (C) in Example 3, ADRs 1 to 4 were 7,200 Å / sec and 53 Å / sec, 480 Å / sec, respectively. It was less than 1 Å / sec, showing excellent results.
Further, it was found that the Tg of the coating film of the positive photoresist composition was as high as 191 ° C., and the heat resistance was also excellent.

Similarly, as shown in Table 1, for the positive photoresist composition of the present invention prepared from the novolak resin (D) in Example 4, ADRs 1 to 4 were 8,000 Å / sec and 56 Å / sec, 540 Å / respectively. It was less than 1 Å / sec, showing excellent results.
Further, it was found that the Tg of the coating film of the positive photoresist composition was as high as 196 ° C., and the heat resistance was also excellent.

On the other hand, Comparative Example 1 is an example of a positive photoresist composition using a known phenolic novolak resin obtained by condensation-reacting 2-hydroxybenzoic acid with 3,4-dihydroxybenzaldehyde as an alkali-soluble resin.
Regarding the positive photoresist composition prepared in Comparative Example 1, when the developer was a 2.38% tetramethylammonium hydroxide aqueous solution, the positive photoresist composition did not contain a photosensitizer corresponding to the exposed portion. It was found that the substance had a slow alkali dissolution rate of 3,500 Å / sec and insufficient sensitivity (ADR1). Further, when the developer is a 15% aqueous sodium carbonate solution, the positive photoresist composition containing no photosensitizer corresponding to the exposed portion has a slow alkali dissolution rate of less than 1 Å / sec and is insensitive. It turned out to be sufficient (ADR3).
Further, it was found that the Tg of the coating film of the positive photoresist composition was as low as 52 ° C. and the heat resistance was insufficient.

Further, Comparative Example 2 is an example of a positive photoresist composition using a known phenolic novolak resin obtained by condensing m-cresol and p-cresol with formaldehyde as an alkali-soluble resin.
Regarding the positive photoresist composition prepared in Comparative Example 2, when the developer was a 2.38% tetramethylammonium hydroxide aqueous solution, the positive photoresist composition did not contain a photosensitizer corresponding to the exposed portion. It was found that the substance had a slow alkali dissolution rate of 110 Å / sec and insufficient sensitivity (ADR1). Further, when the developer is a 15% aqueous sodium carbonate solution, the positive photoresist composition containing no photosensitizer corresponding to the exposed portion has a slow alkali dissolution rate of less than 1 Å / sec and is insensitive. It turned out to be sufficient (ADR3).
Further, it was found that the Tg of the coating film of the positive photoresist composition was as low as 110 ° C. and the heat resistance was insufficient.

Claims (9)

A positive photoresist composition containing a novolak-type phenol resin (C) obtained by condensing an aromatic compound (A) represented by the following formula (1) and an aliphatic aldehyde (B). thing.

(In the formula, R ₁ and R ₂ independently represent H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, and a halogen atom, and R ₃ and R are independent of each other. Represents a structural site having one or more alkoxy groups, halogen groups, and hydroxyl groups on H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms or a hydrocarbon group, and m and n are independently 0 or 0, respectively. Represents an integer of 1 to 4) The positive photoresist composition according to claim 1, wherein the aliphatic aldehyde (B) is formaldehyde and / or paraformaldehyde. The aromatic compound (A) is obtained by polycondensing a phenol compound with an aromatic aldehyde having a carboxyl group or an ester derivative thereof and / or an aromatic ketone having a carboxyl group or an ester derivative thereof. Alternatively, the positive type photoresist composition according to 2. The positive photoresist composition according to claim 3, wherein the aromatic aldehyde having a carboxyl group is formylbenzoic acid. The positive photoresist composition according to any one of claims 1 to 4, wherein the aromatic compound (A) is used for condensation with an aliphatic aldehyde (B) after being isolated and purified. thing. A positive photoresist characterized by isolating and purifying the aromatic compound (A) represented by the following formula (1) and then condensing it with an aliphatic aldehyde (B) to obtain a novolak-type phenol resin (C). A method for producing a resist composition.

(In the formula, R ₁ and R ₂ independently represent H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group, and a halogen atom, and R ₃ and R are independent of each other. Represents a structural site having one or more alkoxy groups, halogen groups, and hydroxyl groups on H or an aliphatic hydrocarbon group having 1 to 9 carbon atoms or a hydrocarbon group, and m and n are independently 0 or 0, respectively. Represents an integer of 1 to 4) The method for producing a positive photoresist composition according to claim 6, wherein the aliphatic aldehyde (B) is formaldehyde and / or paraformaldehyde. 6. The aromatic compound (A) is obtained by polycondensing a phenol compound with an aromatic aldehyde having a carboxyl group or an ester derivative thereof and / or an aromatic ketone having a carboxyl group or an ester derivative thereof. Alternatively, the method for producing a positive photoresist composition according to 7. The method for producing a positive photoresist composition according to claim 8, wherein the aromatic aldehyde having a carboxyl group is formylbenzoic acid.

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