WO2012157543A1

WO2012157543A1 - Condensation product, photosensitive composition, method for producing photosensitive composition, and method for forming negative resist pattern using photosensitive composition

Info

Publication number: WO2012157543A1
Application number: PCT/JP2012/062094
Authority: WO
Inventors: 毅小川; 本城　啓司; 赤松　佳則; 山中　一広
Original assignee: セントラル硝子株式会社
Priority date: 2011-05-13
Filing date: 2012-05-11
Publication date: 2012-11-22
Also published as: JP2012254968A

Abstract

Disclosed is a condensation product of alkoxy silanes, which is obtained by condensing an alkoxy silane A represented by Si(OR¹)₄, an alkoxy silane B represented by (R²)Si(OR¹)₃ and an alkoxy silane C represented by (R²)₂Si(OR¹)₂ at a molar ratio of alkoxy silane A:alkoxy silane B:alkoxy silane C within the range of 0-70:30-100:0-70. In this connection, R¹ represents a methyl group or an ethyl group, and R² represents a methyl group, an ethyl group or a phenyl group. This condensation product has excellent storage stability. A film derived from this condensation product is hard and does not suffer from cracking even if the film thickness thereof is 1.5 μm or more.

Description

Condensate, photosensitive composition, method for producing the same, and method for forming negative resist pattern using the same

The present invention relates to a condensate using a specific alkoxysilane, a photosensitive composition and a method for producing the same, and a negative resist pattern formed of a photosensitive resin composition on a substrate such as a glass substrate or a silicon substrate. The present invention relates to a method for forming a mold resist pattern.

Background of the Invention

In liquid crystal displays, touch panels, organic EL, etc., various protective films or insulating films are used.

An epoxy resin film formed by a wet method is mainly used as a protective film for protecting the color filter of the liquid crystal.

On the other hand, as the insulating film, there is an insulating film for TFT in a TFT (Thin Film Transistor) liquid crystal display, and a SiN film formed mainly by a CVD (Chemical Vapor Deposition) method is used.

The protective film and insulating film have higher heat resistance to cope with the recent increase in response speed of TFT liquid crystal displays and higher brightness of backlight light sources, compared to the conventional materials described above. There is a demand for a material capable of wet film formation that has an advantage of film formation and cost advantages to cope with an increase in area.

For example, a condensate obtained by hydrolysis and condensation reaction of alkoxysilane (hereinafter sometimes simply referred to as a condensate) has excellent heat resistance, transparency in the visible light region, and adhesion to glass substrates and silicon substrates. It is known as a material.

The condensate has a high solubility in organic solvents by specifying the type and composition of alkoxysilane used as a raw material and devising a manufacturing method, so that wet film formation is possible. Alternatively, it is a promising material for use as an insulating film.

Also, if the content of silicon in the condensate is large, it becomes a promising material as a hard mask as well as various insulating films. For example, when an organic polymer is used as an insulating film of an integrated circuit, it is difficult to distinguish and etch the resist and the insulating film because they are the same organic material as the resist film to which a fine pattern is transferred. Therefore, an inorganic layer may be provided between the resist and the insulating film, and this layer is called a hard mask.

In the field of displays and semiconductors, thin films are often processed into various shapes on a substrate, and photolithography is used at that time. In photolithography, a resist film is formed on a substrate such as a glass substrate or a silicon substrate, and the resist film is irradiated and exposed through a photomask having a pattern. This is a technique for forming a resist pattern to which a mask pattern is transferred. In the case of forming a pattern on the protective film or the insulating film, it is necessary to form a resist pattern on these films and then perform etching to form a pattern.

Currently, a resist material using the condensate that can be patterned by photolithography has been developed as the material used for the protective film or insulating film, and if these are used, both steps of resist coating and etching can be omitted. Therefore, shortening of the manufacturing process and cost reduction are expected.

For example, Patent Document 1 discloses a negative resist material characterized by containing a resin having a silanol group and a compound that generates an acid upon irradiation with high energy rays.

Patent Document 2 discloses (1) an alkali-soluble siloxane polymer having a methyl group directly connected to silicon and a silanol group and having a silanol content of 0.1 to 2.0 (provided that the silanol content is red silicon silanol groups and 1271cm ^-1 of 900 cm ^-1 due to external spectroscopy -. pointing absorbance ratio or Abs of the absorption peak by methyl group ^{(900cm -1) / Abs (1271cm} -1)) (2) by the action of radiation The photosensitive resin composition which has as a main component the compound (3) solvent which generate | occur | produces a reaction accelerator is disclosed.

Patent Document 3 discloses a component (X) composed of phenyltriethoxysilane or phenyltrimethoxysilane, a component (Y) composed of methyltriethoxysilane or methyltrimethoxysilane, and a component composed of triethoxysilane or trimethoxysilane. Formation of a film containing an alkoxysilane condensate (A) obtained by reacting (Z) with a specific ratio, and an acid generator (B) that generates an acid by an external stimulus such as light or heat A composition for use, a method for producing a pattern film using the composition, and an insulating film for electronic devices are disclosed.

Also, the condensate obtained by hydrolysis and condensation reaction of alkoxysilane has the following two problems.

The first problem is the storage stability of the condensate. This is because the silanol (Si—OH) group remaining in the condensate undergoes a condensation reaction gradually during the storage period, and the condensation proceeds and the molecular weight increases. The condensate changes in physical properties such as viscosity and solubility in an organic solvent, and it is difficult to uniformly form a wet film, making it difficult to obtain a desired film.

The second problem is that it is difficult to obtain a hard film having a film thickness of 1.5 μm or more. In particular, a protective film or an insulating film in the field of liquid crystal display or the like often requires a thickness, a pencil hardness HB of 1.5 μm or more, and preferably a hardness of 2H or more. The condensate needs to be heated and fired at a high temperature after wet film formation, and finally, it is difficult to obtain a film having a film thickness of 1.5 μm or more without cracks at the film hardness.

As described above, in the condensate obtained by hydrolysis and condensation reaction of alkoxysilane and used for a protective film or insulating film, it has excellent storage stability and a pencil hardness of HB of 1.5 μm or more and a hardness of HB or more. However, there is no one that solves the two problems of obtaining a hard film of preferably 2H or more.

Japanese Patent Laid-Open No. 2-129642 JP-A-10-246960 Pamphlet of International Publication WO2008 / 047654

Under the circumstances as described above, the condensate obtained by hydrolysis and condensation reaction of alkoxysilane is excellent in storage stability, which was difficult with the condensate obtained by hydrolysis and condensation of alkoxysilane by the conventional method. , And the film thickness when the condensate is a hard film, solving the problem of not generating cracks in the film of 1.5 μm or more, excellent in storage stability, and using the condensate to form a film on the substrate There is a need for a condensate for obtaining an excellent film having a film thickness of 1.5 μm or more, a pencil hardness of HB or more, and no cracks after heating and baking.

Further, a photosensitive composition obtained by adding a photoacid generator that generates acid by the action of high energy rays to the condensate of the present invention, and applying the photosensitive composition onto a substrate to form a resist film, followed by photolithography Therefore, there is a demand for a negative resist pattern forming method for forming a negative resist pattern by irradiating a high energy beam.

As a result of studies on condensates obtained from various alkoxysilanes as raw materials, the present inventors have used three types of alkoxysilanes having a specific structure as raw materials, used them at specific composition ratios, water, organic After the hydrolysis and condensation reaction are performed by adding a solvent and an acid catalyst, the acid catalyst is removed by extraction with water, and the condensate obtained by further removing the organic solvent is excellent in storage stability and the solvent is removed. In addition, when applied to the substrate, it was found that after heating and firing, a hard film having a film thickness of 1.5 μm or more and having no crack of pencil hardness HB or more can be obtained, and the present invention was completed.

Specifically, the present invention is as follows.

[Invention 1]
General formula (1): Si (OR ¹ ) ₄
(In formula (1), each R ¹ is independently a methyl group or an ethyl group.)
An alkoxysilane A represented by:
General formula (2): (R ² ) Si (OR ¹ ) ₃
(In formula (2), each R ¹ is independently a methyl group or an ethyl group, and each R ² is independently a methyl group, an ethyl group, or a phenyl group.)
And the general formula (3): (R ² ) ₂ Si (OR ¹ ) ₂
(In Formula (3), R ¹ is each independently a methyl group or an ethyl group, and R ² is independently a methyl group, an ethyl group, or a phenyl group.)
An alkoxysilane condensate obtained by condensing alkoxysilane C represented by the following formula in terms of molar ratio: alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70.

In order to obtain the condensate of the invention 1, in addition to the raw material alkoxysilanes A to C, water for hydrolyzing the alkoxysilanes A to C, a water-soluble organic solvent B as a reaction solvent, preferably an alcohol, As a catalyst for proceeding the condensation reaction, the condensation reaction is preferably performed using acetic acid. The condensate present in the reaction solution after the condensation reaction is extracted with a water-insoluble organic solvent C that is immiscible with water, and then acetic acid contained in the organic solvent C is removed by washing with water. After removing a trace amount of water dissolved in the organic solvent C, the organic solvent C is removed by distillation under reduced pressure to obtain the desired condensate.

[Invention 2]
General formula (1): Si (OR ¹ ) ₄
(In formula (1), each R ¹ is independently a methyl group or an ethyl group.)
An alkoxysilane A represented by:
General formula (2): (R ² ) Si (OR ¹ ) ₃
(In formula (2), each R ¹ is independently a methyl group or an ethyl group, and each R ² is independently a methyl group, an ethyl group, or a phenyl group.)
And the general formula (3): (R ² ) ₂ Si (OR ¹ ) ₂
(In Formula (3), R ¹ is each independently a methyl group or an ethyl group, and R ² is independently a methyl group, an ethyl group, or a phenyl group.)
Consisting of an alkoxysilane C represented by
Expressed as a molar ratio, water, water-soluble organic solvent B, and acid catalyst are added to alkoxysilane mixture D in which alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70. A first step of making the mixture before condensation;
A second step of hydrolyzing and condensing the pre-condensation mixture to produce a condensate in the reaction system;
A third step comprising a step of extracting and removing the acid catalyst from the reaction system with water and a step of extracting the condensate with a water-insoluble organic solvent C to obtain a condensate solution;
A method for producing a condensate of alkoxysilane, comprising a fourth step of removing the organic solvent C from the condensate solution.

The alkoxysilane mixture D is expressed in terms of molar ratio: alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70, alkoxysilane A, alkoxysilane B and alkoxysilane C mixture.

[Invention 3]
The method for producing a condensate according to Invention 2, wherein water is used in a number of moles of 1.5 to 5 times the number of moles of alkoxy groups of the alkoxysilane mixture D.

[Invention 4]
The method for producing the condensate of Invention 2 or Invention 3, wherein the organic solvent B is an alcohol.

[Invention 5]
The method for producing a condensate according to any one of Inventions 2 to 4, wherein the acid catalyst is acetic acid.

Next, a photosensitive composition can be produced by adding a photoacid generator and an organic solvent A to the condensate of Invention 1. Specifically, the photosensitive composition is produced by dissolving the condensate of the invention 1 in an organic solvent A capable of dissolving the condensate, and adding a photoacid generator that generates acid by the action of high energy rays. it can.

[Invention 6]
A photosensitive composition comprising the condensate of the invention 1, a photoacid generator and an organic solvent A.

[Invention 7]
The photosensitive composition of invention 6, wherein the organic solvent A is a polar solvent.

The photosensitive composition of the invention 6 or the invention 7 is obtained by the method for producing a photosensitive composition of any one of the inventions 8 to 11 shown below.

[Invention 8]
General formula (1): Si (OR ¹ ) ₄
(In formula (1), each R ¹ is independently a methyl group or an ethyl group.)
An alkoxysilane A represented by:
General formula (2): (R ² ) Si (OR ¹ ) ₃
(In formula (2), each R ¹ is independently a methyl group or an ethyl group, and each R ² is independently a methyl group, an ethyl group, or a phenyl group.)
And the general formula (3): (R ² ) ₂ Si (OR ¹ ) ₂
(In Formula (3), R ¹ is each independently a methyl group or an ethyl group, and R ² is independently a methyl group, an ethyl group, or a phenyl group.)
Consisting of an alkoxysilane C represented by
Expressed as a molar ratio, water, water-soluble organic solvent B, and acid catalyst are added to alkoxysilane mixture D in which alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70. A first step of making the mixture before condensation;
A second step of hydrolyzing and condensing the pre-condensation mixture to produce a condensate in the reaction system;
A third step having a step of extracting and removing the acid catalyst from the reaction system with water and a step of extracting the condensate with a water-insoluble organic solvent C to obtain a condensate solution;
A method for producing a photosensitive composition, comprising a fourth step of removing the organic solvent C from the condensate solution and a fifth step of adding the photoacid generator and the organic solvent A.

[Invention 9]
The method for producing a photosensitive composition according to Invention 8, wherein water is used in an amount of 1.5 to 5 times the number of moles of the alkoxy group of the alkoxysilane mixture D.

[Invention 10]
The method for producing a photosensitive composition according to Invention 8 or 9, wherein the organic solvent B is alcohol.

[Invention 11]
The method for producing a photosensitive composition according to any one of inventions 8 to 10, wherein the acid catalyst is acetic acid.

Using the photosensitive composition of Invention 6 or Invention 7, a film is obtained by wet-forming a film on a substrate such as a glass substrate or a silicon substrate and pre-baking the substrate. By irradiating this film with high energy rays through a photomask, acid is generated from the photoacid generator in the irradiated part, and condensation of silanol groups proceeds in the irradiated part film, resulting in a condensate in the irradiated part. The condensation further accelerates and becomes insoluble in the alkali developer, and only the unirradiated portion of the film dissolves in the alkali developer and is developed to form a negative resist pattern to which the photomask pattern is transferred.

Thereafter, the thin film is heated and baked at a high temperature to reduce the silanol groups remaining in the negative resist pattern, thereby obtaining a display protective film or insulating film, a semiconductor hard mask or insulating film.

[Invention 12]
The film formed by coating the photosensitive composition of the invention 6 or 7 on a substrate is irradiated with high energy rays to generate an acid in the irradiated part to further accelerate the condensation of the condensate in the irradiated part, thereby A method for forming a negative pattern, wherein the negative pattern is formed by removing a film in an unirradiated portion after insoluble in a developer.

[Invention 13]
The method of forming a negative pattern according to the invention 12, wherein the high energy rays to be irradiated are electromagnetic waves having a wavelength of 400 nm or less or electron beams.

The condensate of the present invention is excellent in storage stability, and when coated on a substrate such as a glass substrate or a silicon substrate to form a film, after firing, it has cracks with a film thickness of 1.5 μm or more and a pencil hardness of HB or more. It is easy to obtain no membrane. For example, when the condensate of the present invention was wet-coated as a solution to form a thin film, the occurrence of cracks was not confirmed even when the film thickness was 1.5 μm or more, and the pencil hardness was H or more.

Furthermore, the condensate of the present invention has high heat resistance, high transparency in visible light, excellent adhesion to a glass substrate or silicon substrate, and low water absorption.

General formula (1): alkoxysilane A represented by Si (OR ¹ ) ₄ , general formula (2): alkoxysilane B represented by (R ² ) Si (OR ¹ ) ₃ and general formula (3) : Is a graph showing a preferred molar ratio of alkoxysilane C represented by (R ² ) ₂ Si (OR ¹ ) ₂ .

Detailed description

Hereinafter, the condensate, the photosensitive composition of the present invention, a method for producing the same, and a method for forming a negative pattern using the same will be described in detail.

1. Condensate The condensate of the present invention was subjected to hydrolysis and condensation reactions using various alkoxysilanes having a specific structure as raw materials, using them in specific ratios, adding water, an organic solvent B and an acid catalyst. Thereafter, the acid catalyst was removed by extraction with water, and the organic solvent B was further removed.

That is, the present invention relates to general formula (1): Si (OR ¹ ) ₄
(In formula (1), each R ¹ is independently a methyl group or an ethyl group.)
An alkoxysilane A represented by:
General formula (2): (R ² ) Si (OR ¹ ) ₃
(In Formula (2), R ¹ is independently a methyl group or an ethyl group, and R ² is independently a methyl group, an ethyl group, or a phenyl group.)
And alkoxysilane B represented by general formula (3): (R ² ) ₂ Si (OR ¹ ) ₂
(In Formula (3), each R ¹ is independently a methyl group or an ethyl group, and each R ² is independently a methyl group, an ethyl group, or a phenyl group.)
The alkoxysilane C represented by the formula (1) is represented by a molar ratio, and the alkoxysilane A: alkoxysilane B: alkoxysilane C is condensed in the range of 0 to 70:30 to 100: 0 to 70. To do.

The condensate of the present invention is a complex three-dimensional network structure formed by hydrolysis and condensation reaction of various alkoxysilanes having a specific structure.

For example, the condensate obtained from the alkoxysilane B represented by the general formula (2) in which R ² is a phenyl group and the alkoxysilane C represented by the general formula (3) in which R ² is a methyl group includes: The structure shown below is considered to be included. A bond shown by a wavy line in the structure means that a network of siloxane bonds continues beyond that.

In the present invention, a condensate that is excellent in storage stability by using alkoxysilanes A to C and that can form a hard film having a film thickness of 1.5 μm or more and a pencil hardness of H or more without cracks at the time of film formation. In order to obtain the above, it is preferable to perform condensation in the range of alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70 in terms of molar ratio. Further, preferably, expressed in terms of mol%, from 0% to 70% alkoxysilane A, from 30% to less than 100 mol% alkoxysilane B, and from 0% to 70% alkoxysilane C. In order to obtain a hard film, it is preferable to use alkoxysilane A or alkoxysilane C as an essential composition.

If the amount of alkoxysilane A is more than 70 mol%, the solid content tends to precipitate, the storage stability is poor, the film obtained from the condensate becomes hard, and cracks occur when the film thickness is 1.5 μm or more. Is easy to enter. If the alkoxysilane B is less than 30 mol%, it is difficult to obtain a hard film. When the amount of alkoxysilane C is more than 70 mol%, it is difficult to obtain a hard film. Further, preferably, the molar ratio of alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 40:30 to 90: 0 to 50.

Further, preferably, alkoxysilanes A to C are mixed and used at a molar percentage ratio within a shaded range surrounded by five points A, B, C, D and E shown in FIG.

The molar ratios of alkoxysilanes A to C at each point in FIG. 1 are as follows: A is alkoxysilane A: alkoxysilane B: alkoxysilane C = 40: 30: 30, B is alkoxysilane A: alkoxysilane B: alkoxy Silane C = 0: 50: 50, C is alkoxysilane A: alkoxysilane B: alkoxysilane C = 0: 90: 10, D is alkoxysilane A: alkoxysilane B: alkoxysilane C = 20: 80: 0, E Is alkoxysilane A: alkoxysilane B: alkoxysilane C = 40: 60: 0.

When the raw material alkoxysilane is out of the molar ratio of alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70, the resulting condensate is (1 ) Storage stability is inferior, (2) It is difficult to form a film having a thickness of 1.5 μm or more without cracks, or (3) Sufficient film hardness cannot be obtained after heating and baking at high temperature. It is difficult to put into practical use as a protective film or insulating film for displays and semiconductor applications. Furthermore, it is preferably within the range of the shaded portion surrounded by five points A, B, C, D, and E shown in FIG.

The condensate is dissolved in an organic solvent A, preferably a polar solvent, and wet-formed on a substrate such as a glass substrate or a silicon substrate. For example, after coating on the substrate, pre-baking, that is, heating, the organic solvent A is removed to form a film. If this film is heated and fired, it can be used as a protective film or insulating film for displays or semiconductors, or as a hard mask or insulating film in the field of semiconductor manufacturing.

2. Method for Producing Condensate In the production of the condensate of the present invention, water for hydrolyzing alkoxysilanes A to C after the above-mentioned alkoxysilanes A to C are charged in a reaction vessel at room temperature, an organic solvent as a reaction solvent B, preferably an alcohol, an acid catalyst for proceeding the condensation reaction, preferably acetic acid is added to the reactor as a pre-condensation mixture, and the contents are stirred while the reaction solution is heated to 90 ° C., The hydrolysis and condensation reaction proceeds to produce a condensate.

At this time, in order to prevent unreacted raw materials, water, alcohol and acetic acid in the reaction system from being distilled out of the reaction system, the reaction vessel is preferably provided with a condenser. The time required for the condensation reaction is usually 3 to 5 hours. After the condensation reaction, the temperature of the reaction solution is lowered to room temperature (20 ° C.), and in order to remove the condensate present in the reaction system, contact extraction is performed with an organic solvent C that is not miscible with water, that is, a water-insoluble solvent. Acetic acid contained in the organic solvent C is removed by washing with water.

Further, after removing a trace amount of water dissolved in the organic solvent C using a solid desiccant, the solid desiccant is removed by filtration. Finally, the target condensate is obtained by removing the organic solvent C under reduced pressure. Alternatively, water may be simultaneously removed under reduced pressure in the process of removing the organic solvent C under reduced pressure without using a solid desiccant.

The molar equivalent of water used in the hydrolysis and condensation reaction for obtaining the condensate of the present invention is 1.5 to 5 times the total molar equivalent of the alkoxy groups of the raw material alkoxysilane. When the amount is less than 1.5 times equivalent, hydrolysis is not efficiently performed and a condensate having poor storage stability is obtained. When it exceeds 5 times the molar equivalent, productivity is extremely lowered, which is not preferable.

In the hydrolysis and condensation reaction for obtaining the condensate or photosensitive composition of the present invention, the organic solvent B is preferably an alcohol, such as ethanol, normal propanol, isopropanol or butanol.

In order to obtain the condensate or photosensitive composition of the present invention, the organic solvent C used for extracting the condensate present in the reaction system after the condensation reaction and dissolving the condensate and immiscible with water is diethyl. There may be mentioned ether, isopropyl ether or dibutyl ether.

The solid desiccant used for removing water from the organic solvent C after the condensation reaction in order to obtain the condensate or photosensitive composition of the present invention includes magnesium sulfate.

3. Photosensitive composition and method for producing the same Next, a photoacid generator for generating an acid by the action of high energy rays by dissolving the condensate of the present invention in an organic solvent A in which the condensate can be dissolved, preferably a polar solvent. It is set as the photosensitive composition by adding.

Examples of the organic solvent A used in the photosensitive composition of the present invention include propylene glycol monomethyl acetate (hereinafter abbreviated as PGMEA), propylene glycol monomethyl ether, cyclohexanone, γ-butyrolactone, methyl ethyl ketone, methyl isobutyl ketone, N, N-dimethyl. Examples include formamide or N-methylpyrrolidone.

As a photoacid generator that generates acid by the action of high energy rays used in the photosensitive composition of the present invention, that is, generates acid by absorbing high energy rays to be irradiated, specifically, triphenyl is used. Sulfonium trifluoromethanesulfonate, manufactured by BASF USA, trade name, Irgacure PAG121, Irgacure PAG103, Irgacure CGI1380, Irgacure CGI725, Midori Chemical Co., Ltd., trade names, PAI-101, PAI-106, NAI-105, NAI-106 , TAZ-110, TAZ-204, manufactured by San Apro Co., Ltd., trade name, CPI-200K, CPI-210S, CPI-101A, CPI-110A, CPI-100P, CPI-110P, CPI-100TF, HS-1, S-1A, HS-1P, HS-1N, HS-1TF, HS-1NF, HS-1MS, HS-1CS, LW-S1, LW-S1NF, manufactured by Sanwa Chemical Co., Ltd., trade name, TFE-triazine, Mention may be made of TME-triazine or MP-triazine.

4). Method for Forming Negative Resist Pattern The solution-like photosensitive composition is wet-deposited on a substrate such as a glass substrate or a silicon substrate. For example, after coating on the substrate, pre-baking, that is, heating, the organic solvent A is removed to obtain a resist film. This resist film is formed into a negative resist pattern by photolithography. Specifically, the resist film is irradiated with high energy rays through a photomask on which a pattern is formed, and an acid is generated from the photoacid generator in the irradiated part to further promote the condensation reaction of the resist film in the irradiated part, If only the resist film of the part is insolubilized in the developer and then developed with the developer, the unirradiated part is dissolved in the developer, and only the irradiated part remains on the substrate, forming a negative resist pattern. .

Thereafter, the negative resist pattern is heated and baked to condense silanol groups remaining in the pattern. The temperature at the time of thermal firing is preferably a high temperature in order to obtain a thin film with high hardness, but the upper temperature limit depends on the manufacturing process of the display and semiconductor. For example, in an overcoat film forming process in a general liquid crystal display, the upper limit of the heating temperature is 250 ° C.

Examples of the developer used in the method for forming a negative resist pattern using the photosensitive composition of the present invention include tetramethylammonium hydroxide aqueous solution.

The high energy ray used in the method of forming a negative resist pattern using the composition of the present invention is a high pressure mercury lamp having a wavelength of ultraviolet energy or less, specifically a high energy ray having a wavelength of 400 nm or less. UV light, g-line (wavelength 436 nm), h-line (wavelength 405 nm), i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm) or extreme ultraviolet light (wavelength 13.5 nm) Or an electron beam.

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

The weight average molecular weight (Mw) of the condensate was measured in terms of tetrahydrofuran and polystyrene as a solvent using GPC. The thickness of the resist film formed on the silicon substrate was measured using a stylus type surface shape measuring machine, and the pencil hardness of the film formed on the silicon substrate was measured using a scratch hardness tester. The measurement equipment used in this example is shown below.

GPC: manufactured by Tosoh Corporation, product name, HLC-8320GPC, column, manufactured by Tosoh Corporation, product name, TSKgelGMHXL
Stylus type surface profile measuring machine: manufactured by Veeco, USA, product name, Dektak8
Electric pencil scratch hardness tester: Yasuda Seiki Seisakusho Co., Ltd. 553-M

Example 1
[Synthesis of condensate]
In a 1 L three-necked flask equipped with a fluororesin stirring blade and a Dimroth type reflux condenser, 16.22 g of Si (OEt) ₄ as alkoxysilane A and 90 of PhSi (OMe) ₃ as alkoxysilane B were added. .10 g and 27.39 g of Me ₂ Si (OMe) ₂ as alkoxysilane C were charged. The molar ratio was alkoxysilane A: alkoxysilane B: alkoxysilane C = 10: 60: 30.

Next, 102.87 g of isopropanol, 78.56 g of water, 0.06 g of acetic acid, and 0.06 g of acetic acid were charged into the flask, and then the flask was heated to 90 ° C. to perform hydrolysis and condensation reaction. After 3 hours, the reaction solution (reaction system) was returned to room temperature, and 200 ml of isopropyl ether and 200 ml of water were placed in the flask and stirred. Thereafter, the upper layer side of the reaction solution separated into two layers was collected and washed with 200 ml of water three times. Next, after removing a trace amount of water dissolved in isopropyl ether with magnesium sulfate, the magnesium sulfate was filtered off. When isopropyl ether was distilled off under reduced pressure using an evaporator, the desired condensate was obtained as a colorless viscous liquid. Yield, 74.82 g, Mw = 990. The obtained condensate was stored at 5 ° C. for 1 month, but no change was observed in Mw, and the condensate was excellent in storage stability.

[Formation of negative resist pattern using condensate]
5.20 g of the above condensate was dissolved in 4.70 g of PGMEA, and the photoacid generator 5-P-toluenesulfoxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitile (trade name, manufactured by BASF, USA) , Irgacure PAG121) was added to give a photosensitive composition. Using this, a resist film made of the photosensitive composition was formed on a silicon substrate having a diameter of 100 mm with a spin coater at a rotation speed of 1000 rpm and a holding time of 10 seconds, and then the substrate was heated at 150 ° C. for 1 minute. Pre-baked.

Next, the resist film on the silicon substrate was irradiated with ultraviolet light having a wavelength of 365 nm for 1 minute using a mask aligner (mask alignment apparatus, manufactured by SUSS Microtech Co., Ltd., model number, MA6) and a patterned photomask. The silicon substrate was taken out from the mask aligner, and contact-developed for 20 seconds using a tetramethylammonium hydroxide aqueous solution having a concentration of 2.38% by mass. A negative resist pattern including a line having a minimum width of 10 μm was formed on the substrate. Thereafter, the silicon substrate was put in an oven at 250 ° C. for 1 hour, and the negative resist pattern was heated and baked. As a result, a silicon substrate with a negative resist pattern having a thickness of 7.0 μm was obtained. No crack was observed in the resist film on the silicon substrate, the pencil hardness was HB, and a good negative resist pattern was obtained.

Example 2
[Synthesis of condensate]
In a three-necked flask similar to that used in Example 1, 31.69 g of Si (OEt) ₄ as alkoxysilane A, 60.12 g of PhSi (OMe) ₃ as alkoxysilane B, and Me as alkoxysilane C 36.52 g of ₂ Si (OMe) ₂ was charged. The molar ratio was alkoxysilane A: alkoxysilane B: alkoxysilane C = 20: 40: 40.

Next, 102.13 g of isopropanol, 77.24 g of water and 0.06 g of acetic acid were charged into a three-necked flask, and a condensate was synthesized in the same procedure as in Example 1. The desired condensate was obtained as a colorless viscous liquid, yield, 67.77 g, Mw = 1130. The obtained condensate was stored at 5 ° C. for 1 month, but no change was observed in Mw, and the condensate was excellent in storage stability.

[Formation of negative resist pattern using condensate]
5.67 g of the above condensate was dissolved in 5.30 g of PGMEA, and 0.05 g of the same photoacid generator (trade name, Irgacure PAG121, manufactured by BASF, USA) as in Example 1 was added to obtain a photosensitive composition. Using the photosensitive composition, a resist film made of the photosensitive composition was formed on a silicon substrate having a diameter of 100 mm with a spin coater at a rotation speed of 1000 rpm and a holding time of 20 seconds, and then the silicon substrate was heated at 150 ° C. Pre-baked by heating for 1 minute.

Then, using the same apparatus as in Example 1, the resist film was irradiated with ultraviolet light in the same procedure. As a result, a negative resist pattern including a line having a minimum width of 10 μm was formed. Then, when the substrate was heated and baked in an oven at 250 ° C. for 1 hour, a silicon substrate with a negative resist pattern having a film thickness of 3.1 μm was obtained. Cracks were not observed in the resist pattern on the silicon substrate, the pencil hardness of the pattern was H, and a good negative resist pattern was obtained.

Example 3
[Synthesis of condensate]
In a three-necked flask similar to that used in Example 1, 17.23 g of Si (OEt) ₄ as alkoxysilane A, 130.18 g of PhSi (OMe) ₃ as alkoxysilane B, and Me as alkoxysilane C were used. ₂ 9.93 g of Si (OMe) ₂ was charged. The molar ratio was alkoxysilane A: alkoxysilane B: alkoxysilane C = 10: 80: 10.

Next, 118.20 g of isopropanol, 89.02 g of water and 0.06 g of acetic acid were charged into a three-necked flask, and a condensate was synthesized in the same procedure as in Example 1. The desired condensate was obtained as a colorless viscous liquid, yield, 93.43 g, Mw = 970. The obtained condensate was stored at 5 ° C. for 1 month, but no change was observed in Mw, and the condensate was excellent in storage stability.

[Formation of negative resist pattern using condensate]
The above condensate 2.04 was dissolved in 2.02 g of PGMEA, 0.02 g of the same photoacid generator (trade name, Irgacure PAG121, manufactured by BASF, USA) as in Example 1 was added, and the photosensitive composition and did. Using the photosensitive composition, a resist film made of the photosensitive composition was formed on a silicon substrate having a diameter of 100 mm with a spin coater at a rotation speed of 1000 rpm and a holding time of 10 seconds, and then the silicon substrate was heated at 150 ° C. Pre-baked by heating for 30 seconds.

Then, using the same apparatus as in Example 1, the resist film was irradiated with ultraviolet light in the same procedure. As a result, a negative resist pattern including a line having a minimum width of 10 μm was formed. Thereafter, the substrate was heated and baked in an oven at 250 ° C. for 1 hour. As a result, a silicon substrate with a negative resist pattern having a film thickness of 5.0 μm was obtained. Cracks were not observed in the resist pattern on the silicon substrate, the pencil hardness of the pattern was H, and a good negative resist pattern was obtained.

Comparative Example 1
[Synthesis of condensate]
In a three-necked flask similar to that used in Example 1, 126.09 g of Si (OEt) ₄ as alkoxysilane A, 30.03 g of PhSi (OMe) ₃ as alkoxysilane B, and Me ₂ as alkoxysilane C were used. 22.47 g of Si (OEt) ₂ was charged. The molar ratio was alkoxysilane A: alkoxysilane B: alkoxysilane C = 66: 17: 17.

Next, 152.28 g of isopropanol, 114.64 g of water, acetic acid and 0.07 g were charged into a three-necked flask, and a condensate was synthesized in the same procedure as in Example 1. The desired condensate was obtained as a colorless viscous liquid, yield, 66.01 g, Mw = 9363. When the obtained condensate was stored at 5 ° C., gelation of the condensate was observed after 1 week, the gel body was insoluble in tetrahydrofuran, and Mw could not be measured. Thus, the condensate was inferior in storage stability.

[Formation of negative resist pattern using condensate]
8.29 g of the above condensate was dissolved in 8.21 g of PGMEA, and 0.10 g of the same photoacid generator (trade name, Irgacure PAG121, manufactured by BASF, USA) as in Example 1 was added to obtain a photosensitive composition. . Using the photosensitive composition, a resist film made of the photosensitive composition was formed on a silicon substrate having a diameter of 100 mm by spin coating at a rotational speed of 2500 rpm and a holding time of 30 seconds, and then the silicon substrate was heated at 150 ° C. Pre-baked by heating for 30 seconds.

Then, when the resist film was irradiated with ultraviolet light in the same procedure using the same apparatus as in Example 1, a negative resist pattern including a line having a minimum width of 10 μm was formed. Thereafter, when the substrate was heated and fired in an oven at 250 ° C. for 1 hour, a substrate with a negative resist pattern having a film thickness of 1.3 μm was obtained, but cracks were generated in the pattern. Thus, a pattern having a film thickness of 1.3 μm could not be formed without cracks.

Comparative Example 2
[Synthesis of condensate]
In the same three-necked flask as used in Example 1, 26.31 g of Si (OEt) ₄ as alkoxysilane A, 23.97 g of PhSi (OMe) ₃ as alkoxysilane B, and Me as alkoxysilane C ₂ 120.08 g of 2Si (OMe) ₂ was charged. The molar ratio was alkoxysilane A: alkoxysilane B: alkoxysilane C = 10: 10: 80.

Next, 138.55 g of isopropanol, 103.40 g of water and 0.06 g of acetic acid were charged into a three-necked flask, and a condensate was synthesized in the same procedure as in Example 1. The desired condensate was obtained as a colorless viscous liquid, yield, 90.22 g, Mw = 1071. The obtained condensate was stored at 5 ° C. for 1 month, but no change was observed in Mw.

[Formation of negative resist pattern using condensate]
3.11 g of the above condensate was dissolved in 3.08 g of PGMEA, and 0.03 g of a photoacid generator similar to Example 1 (USSF, trade name, Irgacure PAG121) was added to obtain a photosensitive composition. .

Using the photosensitive composition, a resist film made of the photosensitive composition was formed on a silicon substrate having a diameter of 100 mm with a spin coater at a rotation speed of 1000 rpm and a holding time of 10 seconds, and then the silicon substrate was brought to 150 ° C. And prebaked for 2 minutes.

Then, when the resist film was irradiated with ultraviolet light in the same procedure using the same apparatus as in Example 1, a negative resist pattern including a line having a minimum width of 10 μm was formed. Then, when the board | substrate was heat-baked for 1 hour in 250 degreeC oven, the board | substrate with a pattern with a film thickness of 5.4 micrometers was obtained. Although no crack was observed in the thin film on the substrate, the pencil hardness was 7B or less, which was an extremely soft film, and the desired hardness was not obtained.

The condensate of the present invention can be used, for example, as a protective film and an insulating film in the display field such as a liquid crystal display, a touch panel, and an organic EL (Electro Luminescence).

Moreover, since the condensate of the present invention has a relatively large silicon content, it can be used for hard masks and various insulating films in semiconductor manufacturing.

In addition, a photoacid generator that generates acid by the action of high energy rays and an organic solvent A are added to the condensate of the present invention to form a photosensitive composition, and the composition is wet on a substrate such as a glass substrate or a silicon substrate. Apply and form a resist film, irradiate high energy rays using a phytomask by photolithography to generate acid in the irradiated part, further promote condensation of the resist film in the irradiated part to make it insoluble in alkali, By developing with, a negative resist pattern to which the photomask pattern is transferred can be used.

Claims

General formula (1): Si (OR 1 ) 4
(In formula (1), each R 1 is independently a methyl group or an ethyl group.)
An alkoxysilane A represented by:
General formula (2): (R 2 ) Si (OR 1 ) 3
(In formula (2), each R 1 is independently a methyl group or an ethyl group, and each R 2 is independently a methyl group, an ethyl group, or a phenyl group.)
And alkoxysilane B represented by the general formula (3): (R 2 ) 2 Si (OR 1 ) 2
(In Formula (3), R 1 is each independently a methyl group or an ethyl group, and R 2 is independently a methyl group, an ethyl group, or a phenyl group.)
An alkoxysilane C condensate obtained by condensation in the range of alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70.
General formula (1): Si (OR 1 ) 4
(In formula (1), each R 1 is independently a methyl group or an ethyl group.)
An alkoxysilane A represented by:
General formula (2): (R 2 ) Si (OR 1 ) 3
(In formula (2), each R 1 is independently a methyl group or an ethyl group, and each R 2 is independently a methyl group, an ethyl group, or a phenyl group.)
And alkoxysilane B represented by the general formula (3): (R 2 ) 2 Si (OR 1 ) 2
(In Formula (3), R 1 is each independently a methyl group or an ethyl group, and R 2 is independently a methyl group, an ethyl group, or a phenyl group.)
Consisting of an alkoxysilane C represented by
Expressed as a molar ratio, water, water-soluble organic solvent B, and acid catalyst are added to alkoxysilane mixture D in which alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70. A first step of making the mixture before condensation;
A second step of hydrolyzing and condensing the pre-condensation mixture to produce a condensate in the reaction system;
A third step comprising a step of extracting and removing the acid catalyst from the reaction system with water and a step of extracting the condensate with a water-insoluble organic solvent C to obtain a condensate solution;
A method for producing a condensate of alkoxysilane, comprising a fourth step of removing the organic solvent C from the condensate solution.
The method for producing a condensate according to claim 2, wherein water having a mole number of 1.5 to 5 times the number of moles of the alkoxy group of the alkoxysilane mixture D is used.
The method for producing a condensate according to claim 2 or 3, wherein the organic solvent B is an alcohol.
The method for producing a condensate according to any one of claims 2 to 4, wherein the acid catalyst is acetic acid.
A photosensitive composition comprising the condensate according to claim 1, a photoacid generator and an organic solvent A.
The photosensitive composition according to claim 6, wherein the organic solvent A is a polar solvent.
General formula (1): Si (OR 1 ) 4
(In formula (1), each R 1 is independently a methyl group or an ethyl group.)
An alkoxysilane A represented by:
General formula (2): (R 2 ) Si (OR 1 ) 3
(In formula (2), each R 1 is independently a methyl group or an ethyl group, and each R 2 is independently a methyl group, an ethyl group, or a phenyl group.)
And alkoxysilane B represented by the general formula (3): (R 2 ) 2 Si (OR 1 ) 2
(In Formula (3), each R 1 is independently a methyl group or an ethyl group, and each R 2 is independently a methyl group, an ethyl group, or a phenyl group.)
Consisting of an alkoxysilane C represented by
Expressed as a molar ratio, water, water-soluble organic solvent B, and acid catalyst are added to alkoxysilane mixture D in which alkoxysilane A: alkoxysilane B: alkoxysilane C = 0 to 70:30 to 100: 0 to 70. A first step of making the mixture before condensation;
A second step of hydrolyzing and condensing the pre-condensation mixture to produce a condensate in the reaction system;
A third step having a step of extracting and removing the acid catalyst from the reaction system with water and a step of extracting the condensate with a water-insoluble organic solvent C to obtain a condensate solution;
A method for producing a photosensitive composition, comprising a fourth step of removing the organic solvent C from the condensate solution and a fifth step of adding the photoacid generator and the organic solvent A.
The method for producing a photosensitive composition according to claim 8, wherein water is used in an amount of 1.5 to 5 times the number of moles of the alkoxy group of the alkoxysilane mixture D.
The method for producing a photosensitive composition according to claim 8 or 9, wherein the organic solvent B is an alcohol.
The method for producing a photosensitive composition according to claim 8, wherein the acid catalyst is acetic acid.
A film formed by applying the photosensitive composition according to claim 6 or 7 onto a substrate is irradiated with high energy rays to generate an acid in the irradiated portion, thereby further condensing the condensate in the irradiated portion. A method of forming a negative pattern, wherein the negative pattern is formed by removing an unirradiated portion film after being promoted to be insoluble in an alkali developer.
The method for forming a negative pattern according to claim 12, wherein the high-energy radiation to be irradiated is an electromagnetic wave having a wavelength of 400 nm or less, or an electron beam.