KR102358180B1 - Surface roughening method - Google Patents

Abstract

The present invention provides a composition (a3) containing inorganic particles (a1) and an organic resin (a2) on a substrate or on a layer above the substrate, followed by drying and curing to form an organic resin layer (A) It relates to a surface roughening method comprising a first step and a second step of roughening the surface of the same substrate by etching from above the substrate.

Description

Surface roughening method {SURFACE ROUGHENING METHOD}

The present invention relates to a surface roughening method on a substrate, and this method is particularly applicable to a light extraction layer such as an LED.

Recently, LED technology has been used. And, as a technology for improving the luminous efficiency, the study of the light extraction layer is being made.

As a light extraction layer, such as an LED, the method of providing a light scattering layer between the light emitting layer inside an organic electroluminescent element and a board|substrate is proposed (refer patent document 1). As a light-scattering layer, what disperse|distributed the microparticles|fine-particles from which the refractive index differs from this resin to transparent resin disperse|distributed is used. The light emitted from the light emitting part is scattered by the light scattering layer and changes the traveling direction in various directions. As a result of multiple scattering, light incident on the angular region within the total reflection angle at the interface with air can be extracted. In the light scattering layer, since the traveling direction of light changes randomly, it is preferable that the size distribution of the fine particles is wide, the arrangement of the fine particles is random, and the volume fraction of the fine particles is large. Here, when the size distribution of the fine particles is narrow or the volume fraction of the fine particles is small, the scattering ability of the light scattering layer is low. However, when the size distribution of the fine particles is wide, it is difficult to ideally arrange the fine particles in the resin, and if the volume fraction is to be increased when the size distribution of the fine particles is wide, the flatness of the light scattering layer is remarkably reduced, and thus the thin film structure The flatness of the phosphorus light emitting part is damaged, and the reliability of the light emitting device is greatly reduced.

In addition, a three-dimensional diffraction layer comprising a reflective layer and a matrix having a coefficient of variation of 10% or less and a matrix having a refractive index different from that of the fine particles formed on the reflective layer, wherein the volume fraction of the particulates relative to the volume of the three-dimensional diffraction layer is 50% or more, and the particles are arranged to form a first region having short-range periodicity, and the first region again forms a second region in which the first region is adjacent to each other in a random direction. , a light extraction layer is disclosed (see Patent Document 2).

Japanese Patent Laid-Open 2006-107744 Japanese Patent Laid-Open 2009-216862

An object of the present invention is to provide a method for roughening the surface of a substrate. In particular, the present invention uses a layer in which an inorganic material and an organic material are mixed on a substrate, and a portion in which oxygen gas is etched and a surface roughening layer that is not etched on the surface of the substrate by using the difference in the etching rate of the oxygen gas of the inorganic material and the organic material. A method capable of forming, and again using the surface roughening layer as a mask, the surface of the substrate can be roughened by etching with oxygen gas or fluorine-based gas, for example, fine irregularities can be formed on the substrate, and also instead of gas etching An object of the present invention is to provide a method capable of roughening the surface in the same manner even by wet etching using an acidic aqueous solution.

As a first aspect of the present invention, a composition (a3) containing inorganic particles (a1) and an organic resin (a2) is applied on a substrate or on a layer above the substrate, dried and cured to form an organic resin layer (A) A surface roughening method comprising a first step of forming a, and a second step of roughening the surface of the same substrate by etching from above the substrate;

As a second aspect, the etching is performed at least once, and the at least one etching is gas etching using an oxygen-based gas. The surface roughening method according to the first aspect,

As a third aspect, the etching is a surface roughening method according to the first aspect, wherein the etching is wet etching with an acidic aqueous solution;

As a fourth aspect, the surface roughening method according to any one of the first to third aspects, wherein the inorganic particles (a1) are metal oxide particles having an average particle diameter of 5 to 1000 nm;

As a fifth aspect, the composition (a3) comprises a silica sol in which silica is dispersed in an organic solvent as the inorganic particles (a1), and a solution of the organic resin (a2).

As a sixth aspect, the organic resin layer (A) contains the inorganic particles (a1) in a ratio of 5 to 50 parts by mass relative to 100 parts by mass of the organic resin (a2) in any one of the first to fifth aspects The surface roughening method described in

As a seventh aspect, the organic resin (a2) has a repeating unit structure comprising a functional group consisting of a hydroxyl group, a carboxyl group, an amino group, or a combination thereof. In any one of the first to sixth aspects described surface roughening method,

As an eighth aspect, as described in any one of the first to seventh aspects, the etching is performed until forming in the range of 0.1 to 20 with an aspect ratio of the hole expressed by (height)/(diameter) formed on the substrate surface roughening method,

As a ninth aspect, the surface roughening method according to any one of the first to eighth aspects, wherein the organic resin layer (A) is a layer having a film thickness of 0.001 to 10 μm;

As a tenth aspect, in the first step, the composition (b3) containing the organic resin (b2) is applied on the substrate or on a layer above the substrate, followed by drying and curing to form the organic resin layer (B), The second aspect, which is the first 'process of forming the organic resin layer (A) by coating the composition (a3) containing the inorganic particles (a1) and the organic resin (a2) on the organic resin layer (B) again, drying and curing the organic resin layer (A) The surface roughening method according to any one of the ninth aspects,

As an eleventh aspect, the surface roughening method according to the tenth aspect using a resin selected from organic resins (a2) as the organic resin (b2);

As a twelfth aspect, the surface roughening method according to the tenth aspect or the eleventh aspect, wherein the organic resin layer (B) is a layer having a film thickness of 0.001 to 10 μm;

As a thirteenth aspect, the composition (a3) and/or the composition (b3) further contains a crosslinking agent and a crosslinking catalyst. The surface roughening method according to any one of the first to twelfth aspects, and

As a fourteenth aspect, the surface roughening layer to be formed is the surface roughening method according to any one of the first to thirteenth aspects, which is a light extraction layer of an LED.

Through the present invention, a novel method of roughening the surface of a substrate is provided. In particular, the method of the present invention uses a layer in which an inorganic material and an organic material are mixed on the substrate, so that the difference in the etching rate of the oxygen gas of the inorganic material and the organic material can be used. It is possible to form a surface roughening layer that does not have a roughened surface, and again using the surface roughening layer as a mask to roughen the substrate surface by etching with oxygen gas or fluorine-based gas, for example, to form fine irregularities on the substrate, According to the method of the present invention, the surface can be similarly roughened by wet etching using an acidic aqueous solution instead of gas etching.

1 is a cross-sectional view (magnification is 100,000 times) of an organic resin layer (B) and an organic resin layer (A) on the SiO ₂ film-coated wafer obtained in Example 1. FIG.
2 is a cross-sectional view (magnification is 100,000 times, tilt angle is 20 degrees) of the organic resin layer (B) and the organic resin layer (A) on the SiO ₂ film-coated wafer obtained in Example 1;
3 is a cross-sectional view (magnification is 100,000 times) of the organic resin layer (B) and the organic resin layer (A) on the SiO ₂ film-coated wafer obtained in Example 2;
4 is a cross-sectional view (magnification is 100,000 times) of the organic resin layer (B) and the organic resin layer (A) on the SiO ₂ film-coated wafer obtained in Example 4;
Fig. 5 is a cross-sectional view (magnification is 100,000 times) of the organic resin layer (A) on the SiO ₂ film-coated wafer obtained in Example 8.
6 is a cross-sectional view (magnification is 100,000 times) of the organic resin layer (B) on the SiO ₂ film-coated wafer obtained in Comparative Example 1. FIG.
7 is a cross-sectional view (magnification is 100,000 times) obtained by processing the SiO ₂ film on the SiO ₂ film-coated wafer obtained in Example 1. FIG.
FIG. 8 is a cross-sectional view (magnification of 100,000 times, tilt angle of 20 degrees) obtained by processing the SiO ₂ film on the SiO ₂ film-coated wafer obtained in Example 1. FIG.

In the organic EL display, an ITO electrode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and an electrode are formed on a substrate such as glass or transparent plastic.

In addition, an N-type semiconductor, a light emitting region, a P-type semiconductor, an ITO electrode, and a SiO ₂ layer are formed on the sapphire.

In the present invention, it is possible to reduce the reflection of light by roughening the surface of glass, transparent plastic, or SiO ₂ layer used as these light extraction layers, for example, by forming fine irregularities, thereby improving the luminous efficiency.

As a conventional method, there is a method of attaching inorganic particles to a substrate used for a light extraction layer, but adhesion is a problem. Unlike these methods, in the present invention, roughening, for example, irregularities, etc. are formed on the substrate surface by physical etching.

The present invention is to form an organic resin layer (A) by coating a composition (a3) containing inorganic particles (a1) and an organic resin (a2) on a substrate to be harmonized or on a layer above the substrate and drying and curing It includes a first step and a second step of roughening the surface of the same substrate by etching with a gas from above the substrate. Concavities and convexities are formed in the organic resin layer (A) by using the etching rate difference between the oxygen gas of the inorganic particles (a1) and the organic resin (a2) included in the organic resin layer (A). As for the unevenness of the organic resin layer (A), a portion that is etched and a portion that is not etched are formed on the surface of the substrate by subsequent etching of oxygen gas or other gas (fluorine-based gas, chlorine-based gas).

In some cases, the formed unevenness is etched again to form an etched layer toward the lower side of the substrate.

Drying and hardening may be performed simultaneously, and hardening may be performed after drying.

The organic resin layer (A) functions as a mask after oxygen etching. An organic resin layer (B) containing no inorganic particles is formed on a substrate, an organic resin layer (A) containing inorganic particles is formed thereon, and etched with oxygen gas, whereby (A) layer and (B) as a mask Since the film thickness of the layer becomes thick and it becomes easy to generate|occur|produce an etching difference by subsequent oxygen-based gas or other gas etching (for example, fluorine-type gas), it becomes possible to harmonize the board|substrate which has a high aspect-ratio.

Moreover, roughening becomes possible similarly to the above also by wet etching using an acidic aqueous solution instead of gas etching.

The roughening refers to roughening the substrate surface by etching, and causes chemical or physical changes to the substrate surface. As an example, irregularities are formed on the surface of the substrate.

The roughness of the substrate changes depending on the average particle diameter of the inorganic particles or the concentration (ratio) of the inorganic particles included in the organic resin layer (A), and is determined according to the required roughening shape (concave-convex shape) on the substrate.

In the present invention, etching is performed at least once, and among them, at least one etching is performed by gas etching using an oxygen-based gas. The oxygen-based gas is an etching gas containing oxygen as a gas component, and the organic resin (a2) or the organic resin (b2) in the organic resin layer (A) or the organic resin layer (B) present thereunder is etched in the vertical direction by oxygen. In addition, the inorganic particles (a1) in the organic resin layer (A) exhibit etching resistance to oxygen gas. Then, at the stage in which the organic resin layer (A) or the organic resin layer (B) has reached the substrate surface, when etching is continued with an oxygen-based gas, or other gases (eg, a gas containing a fluorine component) can etch the substrate.

In the present invention, the etching can be performed by wet etching with an acidic aqueous solution. The organic resin (a2) or the organic resin (b2) in the organic resin layer (A) or the organic resin layer (B) present under the acidic aqueous solution is etched in the vertical direction, and the inorganic particles (a1) in the organic resin layer (A) ) represents the etching resistance to acidic aqueous solution. Then, at the stage in which the etching of the organic resin layer (A) or the organic resin layer (B) reaches the substrate surface, the substrate can be etched with the acidic aqueous solution continuously.

The acidic aqueous solution used for wet etching contains an acid and water, and may contain hydrogen peroxide or a water-soluble organic solvent as needed. Sulfuric acid, nitric acid, and hydrochloric acid are used as the acid. Water-soluble organic solvents are alcohol-based, ether-based, ketone-based, or ester-based. For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monobutyl ether, propylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, toluene, xylene, methyl ethyl ketone, Cyclopentanone, cyclohexanone, 2-hydroxyethyl propionate, 2-hydroxy-2-methylpropionate ethyl, ethoxyethyl acetate, ethyl hydroxyacetate, 2-hydroxy-3-methylbutanoate, 3- Methyl methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, etc. can be used. These organic solvents are used individually or in combination of 2 or more types.

The concentration of the acid in the total solvent including water and the organic solvent is 0.01 to 97 mass%, and the concentration of hydrogen peroxide in the total solvent is 0.01 to 40 mass%.

In the present invention, both gas etching and wet etching may be combined.

As the inorganic particles (a1) used in the present invention, a metal oxide is used. For example, silicon oxide (silica), titanium oxide, zirconium oxide, aluminum oxide, etc. are mentioned. Silicon oxide (silica) is particularly preferable. As an average particle diameter, it can use in the range of 5-1000 nm, or 5-200 nm, or 10-50 nm. These inorganic particles are preferably added to the organic resin (a2) in a colloidal state, and the sol dispersed in the organic solvent of the inorganic particles (a1) is added to a solution of the organic resin (a2) or the organic resin (a2). A composition (a3) is obtained, and the composition (a3) is coated on a substrate or on a substrate on which an organic resin layer (B) has been previously formed.

Typically, the composition (a3) is obtained by mixing a silica sol in which silica is dispersed in an organic solvent as the inorganic particles (a1) and a solution of the organic resin (a2).

In the composition (a3) and in the organic resin layer (A) obtained by applying the composition (a3), the inorganic particles (a1) are contained in a ratio of 1 to 100 parts by mass relative to 100 parts by mass of the organic resin (a2). .

The organic resin (a2) preferably has, as a functional group, a polar group having a hydroxyl group, a carboxyl group, an amino group, or a combination thereof in the repeating unit. These functional groups are preferable in terms of compatibility with inorganic particles and applicability to a substrate.

Examples of the resin containing the functional group include an acrylic resin, a novolak-based resin, and the like.

As acrylic resin, the homopolymer of the monomer which has a hydroxyl group, a carboxyl group, and an amino group, and the copolymer of these and other resin are mentioned. As a monomer, (meth)acrylic acid, (meth)acrylic acid ester, and a vinyl compound are mentioned.

Monomers having a hydroxyl group, a carboxyl group, or an amino group are (meth)acrylic acid, (meth)acrylamide, hydroxyalkyl (meth)acrylate, carboxyalkyl (meth)acrylate, aminoalkyl (meth)acrylate, hydroxy The homopolymer of monomers, such as styrene, hydroxyvinyl naphthalene, and a vinyl benzoate, and the copolymer of other resin are mentioned. Examples of the other resin include monomers not containing the above functional group, for example, alkyl (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate, phenyl (meth) acrylate, Benzyl (meth)acrylate, styrene, t-butyl styrene, vinyl naphthalene, etc. are mentioned.

The acrylic resin is obtained by radical polymerization or cationic polymerization of these acrylic monomers.

Examples of the novolac resin include a novolak resin obtained by reacting a phenolic hydroxyl group-containing compound or an amino group-containing aromatic compound with an aldehyde compound, a phenolic hydroxyl group-containing compound or an amino group-containing aromatic compound, and a hydroxyl group or a carboxyl group and a novolak resin obtained by reaction of an amino group-containing aldehyde compound. Examples of the compound having a phenolic hydroxyl group include monohydric phenols such as phenol, cresol, salicylic acid and naphthol; dihydric phenols such as catechol and resorcinol; trihydric phenols such as pyrogallol and phloroglycinol; and polynuclear phenols such as phenol, bisphenol A and bisphenol S.

Examples of the amino group-containing aromatic compound include pyrrole, phenylnaphthylamine, phenylindole, and carbazole.

Aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, butylaldehyde, isobutylaldehyde, valeraldehyde, capronaldehyde, 2-methylbutylaldehyde, hexylaldehyde, undecanaldehyde, 7-methoxy- Saturated aliphatic aldehydes such as 3,7-dimethyloctylaldehyde, cyclohexanealdehyde, 3-methyl-2-butylaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, acrolein, methacrolein, etc. heterocyclic aldehydes such as unsaturated aliphatic aldehydes of and aromatic aldehydes such as N,N-dimethylamino)benzaldehyde and acetoxybenzaldehyde. Among these, the aldehyde compound containing a hydroxyl group or a carboxyl group is preferable, for example, hydroxybenzaldehyde, carboxybenzaldehyde, hydroxynaphthaldehyde, carboxynaphthaldehyde, hydroxypyrenealdehyde, and carboxypyrenaldehyde are mentioned.

The phenolic hydroxyl group-containing compound, the amino group-containing aromatic compound, and the aldehyde compound can be used in an amount of 0.1 to 10 equivalents of aldehydes with respect to 1 equivalent of the phenyl group. Examples of the acid catalyst used in the condensation reaction include inorganic acids such as sulfuric acid, phosphoric acid and perchloric acid, organic sulfonic acids such as p-toluenesulfonic acid and p-toluenesulfonic acid monohydrate, and carboxylic acids such as formic acid and oxalic acid. used The amount of the acid catalyst to be used is variously selected depending on the type of acid to be used. Usually, with respect to 100 mass parts of a total of a phenolic hydroxyl-group containing compound, an amino-group containing aromatic compound, and an aldehyde compound, 0.001-1000 mass parts, Preferably it is 0.01-1000 mass parts, More preferably, 0.1-100 mass parts to be.

The condensation reaction is also carried out without a solvent, but is usually carried out using a solvent. As the solvent, any solvent that does not inhibit the reaction can be used. For example, cyclic ethers, such as tetrahydrofuran and a dioxane, are mentioned. Moreover, if the acid catalyst to be used is a liquid one, for example, formic acid, it can also serve as a solvent.

The reaction temperature at the time of condensation is 40 to 200 degreeC normally. The reaction time is variously selected depending on the reaction temperature, and is usually about 30 minutes to 50 hours.

The organic resin (a2) used in the present invention and the organic resin (b2) described below can be exemplified below.

[Formula 1]

The composition (a3) used in the present invention includes the organic resin (a2), the inorganic particles (a1), and a solvent. If necessary, additives such as surfactants may be included.

Solid content of this composition is 0.1-70 mass %, or 0.1-60 mass %. The solid content is the content ratio of all components excluding the solvent in the composition (a3). The organic resin (a2) may be contained in a proportion of 1 to 99.9 mass%, or 20 to 99.9 mass% in the solid content.

The organic resin (a2) used in the present invention has a weight average molecular weight of 600 to 1000000, or 600 to 200000.

In addition, in the surface roughening method of the present invention, a composition (b3) containing an organic resin (b2) is applied on a substrate, dried and cured to form an organic resin layer (B), and again on the organic resin layer (B) A first step of forming the organic resin layer (A) by applying the composition (a3) containing the inorganic particles (a1) and the organic resin (a2), drying and curing (this step is specifically referred to as the first step) and , also includes a second step of roughening the surface of the same substrate by performing etching (gas etching or wet etching) from above the substrate.

The organic resin (b2) of the organic resin layer (B) can be selected from the same range of resins as the organic resin (a2) of the organic resin layer (A). In addition, the same resin may be used for the organic resin (b2) and the organic resin (a2).

The composition (b3) used in the present invention includes the organic resin (b2) and a solvent. If necessary, additives such as surfactants may be included. Solid content of this composition is 0.1-70 mass %, or 0.1-60 mass %. The solid content is the content ratio of all components excluding the solvent in the composition (b3). The organic resin (b2) may be contained in a proportion of 1 to 100% by mass, or 1 to 99.9% by mass, or 50 to 99.9% by mass in the solid content.

The organic resin (b2) used in the present invention has a weight average molecular weight of 600 to 1000000, or 600 to 200000.

The organic resin layer (B) is obtained by coating the composition (b3) on a substrate and drying and curing. Since the organic resin layer (A) is applied on top of the organic resin layer (B), intermixing (layer mixing) In order to prevent contamination, the composition (b3) may further contain a crosslinking agent and a crosslinking catalyst.

In addition, if necessary, the organic resin layer (A) may also contain a crosslinking agent and a crosslinking catalyst in the composition (a3).

Examples of the crosslinking agent used in the composition (a3) or the composition (b3) include a melamine type, a substituted urea type, or a polymer type thereof. Preferably, it is a crosslinking agent having at least two crosslinking substituents, methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine , methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea. Condensates of these compounds can also be used. The amount of the crosslinking agent added varies depending on the coating solvent used, the underlying substrate used, the required solution viscosity, the required film shape, etc., and is 0.001 to 80 mass%, preferably 0.01 to 50 mass%, more preferably based on the total solid Preferably, it is 0.05-40 mass %.

In the present invention, as a catalyst for promoting the crosslinking reaction, p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarinic acid Acidic compounds such as main acid and/or thermal acid generators such as 2,4,4,6-tetrabromocyclohexadienone, benzointosylate, 2-nitrobenzyltosylate, and other organic sulfonic acid alkyl esters may be blended. can A compounding quantity is 0.0001-20 mass % with respect to total solid, Preferably it is 0.0005-10 mass %, More preferably, it is 0.01-3 mass %.

As the surfactant used in the composition (a3) or the composition (b3) in the present invention, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, etc. polyoxyethylene alkyl ethers, polyoxyethylene octyl phenol ether, polyoxyethylene alkyl allyl ethers such as polyoxyethylene nonyl phenol ether, polyoxyethylene polyoxypropylene block copolymers, sorbitan monolaurate, Sorbitan fatty acid esters such as tan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate, EFTOP EF301 , EF303, EF352 (manufactured by Tohkem Products Corporation, trade name), MEGAFAC F171, F173, R40 (manufactured by Dainippon Ink and Chemicals, Inc., trade name), FLUORAD FC430, FC431 (manufactured by Sumitomo 3M Limited, trade name), ASAHI GUARD AG710, Fluorine surfactants, such as SURFLON S382, SC101, SC102, SC103, SC104, SC105, SC106 (made by Asahi Glass Co., Ltd., brand name), Organosiloxane polymer KP341 (made by Shin-Etsu Chemical Co., Ltd.), etc. are mentioned can The compounding quantity of these surfactant is 2.0 mass % or less normally with respect to the total solid of the resist underlayer film material for lithography of this invention, Preferably it is 1.0 mass % or less. These surfactants may be added individually or in combination of 2 or more types.

In the present invention, the solvent used in the composition (a3) or the composition (b3) includes ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, toluene, xylene, methyl ethyl Ketone, cyclopentanone, cyclohexanone, 2-hydroxyethyl propionate, 2-hydroxy-2-methylpropionate ethyl, ethoxyethyl acetate, ethyl hydroxyacetate, 2-hydroxy-3-methylbutanoate methyl; 3-methoxymethyl propionate, 3-methoxy ethyl propionate, 3-ethoxy methyl propionate, 3-ethoxy ethyl propionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, etc. can be used. . These organic solvents are used individually or in combination of 2 or more types.

Moreover, high boiling point solvents, such as propylene glycol monobutyl ether and propylene glycol monobutyl ether acetate, can be mixed and used. Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone and the like are preferable for improving leveling properties.

Next, the surface roughening method of the present invention will be described. After applying the composition (b3) or the composition (a3) to the surface of a substrate or substrate by an appropriate application method such as a spinner or a coater, baking and curing the organic resin layer ( A) or an organic resin layer (B) is prepared.

In the present invention, the organic resin layer (A) has a film thickness of 0.001 to 10 µm, or 0.005 to 3.0 µm, and the organic resin layer (B) has a film thickness of 0.001 to 10 µm, or 0.005 to 3.0 µm.

In addition, the conditions for baking after application are 0.5 to 120 minutes at 80 to 400 ° C.

After forming the organic resin layer (B) on the substrate and forming the organic resin layer (A) thereon, or forming the organic resin layer (A) without forming the organic resin layer (B), and curing under the above conditions, the The surface of the same substrate is roughened by etching with gas from above. It is preferable that the etching gas is first etched with an oxygen-based gas, and accordingly, the portion in which the inorganic particles a1 does not exist is cut off in the vertical direction. In the stage in which the etching reaches the substrate surface, it is also possible to continue etching with an oxygen-based gas, but etching can be performed with other gases (eg, fluorine-based gas), thereby forming irregularities in the substrate and roughening.

The substrate may roughen the surface of the substrate or the coated substrate, including the substrate itself or a coated substrate coated with SiO ₂ or the like on the substrate.

Examples of the oxygen-based gas include oxygen, a mixed gas of oxygen and nitrogen, and a mixed gas of oxygen and argon.

Other gases include fluorine-based gas and chlorine-based gas. and fluorine-containing gases such as CF ₄ , C ₄ F ₈ , C ₄ F ₆ , CHF ₃ , and CH ₂ F ₂ . Moreover, chlorine _- type gas, such as Cl2, can also be used.

In addition, in the present invention, the organic resin layer (B) is formed on the substrate and the organic resin layer (A) is formed thereon, or the organic resin layer (A) is formed on the substrate without forming the organic resin layer (B), After curing under the above conditions, etching is performed with the acidic aqueous solution from above to roughen the surface of the same substrate. By this wet etching, the portion in which the inorganic particles a1 does not exist is cut in the vertical direction. In the stage in which the etching reaches the substrate surface, it is also possible to continue etching with an acidic aqueous solution, thereby forming irregularities on the substrate and roughening.

The substrate may roughen the surface of the substrate or the coated substrate, including the substrate itself or a coated substrate coated with SiO ₂ or the like on the substrate.

Etching with a gas or acidic aqueous solution is performed until it is formed in the range of 0.1 to 20, or 0.1 to 10, with the aspect ratio of the hole represented by (height)/(diameter) formed on the substrate, usually in etching time. is 1 second to 1 hour.

In addition, the substrate existing in the lower layer can be processed by using the roughened surface obtained in this way as a mask. Dry etching or wet etching by gas may be used for processing the lower substrate.

Examples of the dry etching gas include fluorine-based gas and chlorine-based gas. and fluorine-containing gases such as CF ₄ , C ₄ F ₈ , C ₄ F ₆ , CHF ₃ , and CH ₂ F ₂ . Moreover, chlorine _- type gas, such as Cl2, can also be used. Examples of other gases include argon, nitrogen, hydrogen, and oxygen.

Examples of the substrate include silicon, silicon oxide, glass, and sapphire.

Example

<Synthesis Example 1>

In a 100 ml flask, 12.0 g of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 7.3 g of 4-hydroxybenzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), and methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) Ltd.) 0.59 g and propylene glycol monomethyl ether 46.5 g were put. Thereafter, the mixture was stirred under reflux under heating for about 3 hours under reflux. After completion of the reaction, ion exchange treatment was performed to obtain a dark brown phloroglucinol resin solution. The obtained polymer corresponded to Formula (1-1). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 680, and the polydispersity Mw/Mn was 1.3.

<Synthesis Example 2>

In a 300 ml flask, 25.0 g of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 25.4 g of terephthalaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), and 151.1 g of propylene glycol monomethyl ether were placed. Thereafter, the mixture was stirred under reflux under heating for about 2 hours under reflux. After completion of the reaction, ion exchange treatment was performed to obtain a dark brown phloroglucinol resin solution. The obtained polymer corresponded to Formula (1-2). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 2,400, and the polydispersity Mw/Mn was 1.6.

<Synthesis Example 3>

Styrene 7.0 g (manufactured by Tokyo Chemical Industry Co., Ltd.), hydroxyethyl methacrylate 8.7 g (manufactured by Tokyo Chemical Industry Co., Ltd.), 2,2'-azobisisobutyronitrile 0.79 g, propylene After dissolving 38.6 g of glycol monomethyl ether acetate, the solution was heated and stirred at 85° C. for about 20 hours. The obtained polymer corresponded to the said Formula (1-3). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 9,700.

<Synthesis Example 4>

8.0 g of carbazole (manufactured by Tokyo Chemical Industry Co., Ltd.), 28.0 g of 1-naphthaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), p-toluenesulfonic acid monohydrate (Tokyo Chemical Industry) in a 100 ml eggplant-type flask Co., Ltd.) 3.6 g and toluene (manufactured by Kanto Chemical Co., Inc.) 143.8 g were added. After that, the inside of the flask was replaced with nitrogen, heated, and stirred under reflux for about 27 hours. After completion of the reaction, it was diluted with 90.5 g of tetrahydrofuran (manufactured by Kanto Chemical Co., Inc.). The diluted liquid was dripped at 2000 ml of methanol, and it was made to reprecipitate. The obtained precipitate was filtered with suction, and the filtrate was washed with methanol and then dried under reduced pressure at 85°C overnight to obtain 37.9 g of novolak resin. The obtained polymer corresponded to Formula (1-4). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 3,800.

<Preparation example 1 of surface roughening material equivalent to composition (a3)>

0.66 g of the resin obtained in Synthesis Example 1 was mixed with organosilicasol (Nissan Chemical Industries, Ltd. [brand name] PGM-ST, dispersion medium was propylene glycol monomethyl ether, silica concentration was 30 mass %, average particle diameter 10 to 15 nm) 0.37 g, tetramethoxymethyl glycoluril 0.13 g, propylene glycol monomethyl ether 26.2 g, and propylene glycol monomethyl ether acetate 2.6 g were added to make a solution. Thereafter, it was filtered using a polyethylene microfilter having a pore diameter of 0.2 µm to prepare a solution of the composition (a3-1).

<Preparation example 2 of surface roughening material equivalent to composition (a3)>

0.64 g of the resin obtained in Synthesis Example 2 was mixed with organosilicasol (Nissan Chemical Industries, Ltd. [brand name] PGM-ST, dispersion medium was propylene glycol monomethyl ether, silica concentration was 30 mass %, average particle diameter 10 to 15 nm) 0.43 g, tetramethoxymethyl glycoluril 0.13 g, propylene glycol monomethyl ether 20.4 g, and propylene glycol monomethyl ether acetate 8.4 g were added to make a solution. Then, it filtered using the polyethylene microfilter with a pore diameter of 0.2 micrometer, and the solution of the composition (a3-2) was prepared.

<Preparation example 3 of surface roughening material equivalent to composition (a3)>

0.64 g of the resin obtained in Synthesis Example 3 was mixed with an organosilica sol solution (Nissan Chemical Industries, Ltd. [brand name] PGM-ST, dispersion medium was propylene glycol monomethyl ether, silica concentration was 30 mass %, average particle size was 10 to 15 nm) ) 0.43 g, tetramethoxymethyl glycoluril 0.13 g, propylene glycol monomethyl ether 23.3 g, and propylene glycol monomethyl ether acetate 5.5 g were added to prepare a solution. Thereafter, it was filtered using a polyethylene microfilter having a pore diameter of 0.2 µm to prepare a solution of the composition (a3-3).

<Preparation example 4 of surface roughening material equivalent to composition (a3)>

0.65 g of the resin obtained in Synthesis Example 1, 0.38 g of an organosilica sol solution (Nissan Chemical Industries, Ltd. [brand name] IPA-ST, the dispersion medium is isopropanol, the silica concentration is 30% by mass, average particle size 10 to 15 nm); It was added to 0.13 g of tetramethoxymethyl glycoluril and 28.8 g of propylene glycol monomethyl ether, and it was set as the solution. Thereafter, it was filtered using a polyethylene microfilter having a pore diameter of 0.2 µm to prepare a solution of the composition (a3-4).

<Preparation example 5 of surface roughening material equivalent to composition (a3)>

0.65 g of the resin obtained in Synthesis Example 1 was mixed with an organosilica sol solution (MIBK-ST manufactured by Nissan Chemical Industries, Ltd. [brand name] MIBK-ST as a dispersion medium, a silica concentration of 30 mass %, an average particle size of 10 to 15 nm) 0.38 g, 0.13 g of tetramethoxymethyl glycoluril, and 28.8 g of propylene glycol monomethyl ether were added to make a solution. Then, it filtered using the polyethylene microfilter with a pore diameter of 0.2 micrometer, and the solution of the composition (a3-5) was prepared.

<Preparation example 6 of surface roughening material equivalent to composition (a3)>

0.65 g of the resin obtained in Synthesis Example 1 was mixed with an organosilica sol solution (Nissan Chemical Industries, Ltd. [brand name] IPA-ST-L, the dispersion medium was isopropanol, the silica concentration was 30 mass %, the average particle size was 40 to 50 nm) 0.38 g, 0.13 g of tetramethoxymethyl glycoluril, and 28.8 g of propylene glycol monomethyl ether were added to prepare a solution. Thereafter, it was filtered using a polyethylene microfilter having a pore diameter of 0.2 µm to prepare a solution of the composition (a3-6).

<Preparation example 7 of surface roughening material equivalent to composition (a3)>

0.65 g of the resin obtained in Synthesis Example 1 was mixed with an organosilica sol solution (MIBK-ST-L manufactured by Nissan Chemical Industries, Ltd. [brand name], the dispersion medium was methyl isobutyl ketone, the silica concentration was 30 mass %, the average particle diameter was 40 to 50 nm) 0.65 g, tetramethoxymethyl glycoluril 0.13 g, and propylene glycol monomethyl ether 28.8 g were added to make it a solution. Thereafter, it was filtered using a polyethylene microfilter having a pore diameter of 0.2 µm to prepare a solution of the composition (a3-7).

<Preparation example 1 of organic hard mask material corresponding to composition (b3)>

To 2 g of the resin obtained in Synthesis Example 4, 0.3 g of tetramethoxymethyl glycoluril, 0.03 g of pyridinium-p-toluenesulfonate, a surfactant (manufactured by DIC Corporation, product name: MEGAFAC [brand name] R-40, component is a fluorine-based interface (activator) 0.002 g, propylene glycol monomethyl ether acetate 6.8 g, and propylene glycol monomethyl ether 15.8 g were dissolved in it, and it was set as the solution. Then, it filtered using the polyethylene microfilter with a pore diameter of 0.2 micrometer, and the solution of the composition (b3-1) was prepared.

<Example 1>

The solution of the composition (b3-1) obtained in Preparation Example 1 of the organic hard mask material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer) having a thickness of 150 nm. On the obtained organic resin layer (B) (organic hard mask layer), the solution of the composition (a3-1) obtained in Preparation Example 1 of the surface roughening material was applied to the substrate with a spin coater, and baked at 240° C. for 1 minute to obtain the organic resin layer (A) (surface roughening layer) was formed.

<Example 2>

The solution of the composition (b3-1) obtained in Preparation Example 1 of the organic hard mask material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer) having a thickness of 150 nm. On the obtained organic resin layer (B) (organic hard mask layer), the solution of the composition (a3-2) obtained in Preparation Example 2 of the surface roughening material was applied to the substrate with a spin coater, and baked at 240° C. for 1 minute to obtain the organic resin layer (A) (surface roughening layer) was formed.

<Example 3>

The solution of the composition (b3-1) obtained in Preparation Example 1 of the organic hard mask material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer) having a thickness of 150 nm. On the obtained organic resin layer (B) (organic hard mask layer), the solution of the composition (a3-3) obtained in Preparation Example 3 of the surface roughening material was applied to the substrate with a spin coater, and baked at 240° C. for 1 minute to obtain the organic resin layer (A) (surface roughening layer) was formed.

<Example 4>

The solution of the composition (b3-1) obtained in Preparation Example 1 of the organic hard mask material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer) having a thickness of 150 nm. On the obtained organic resin layer (B) (organic hard mask layer), the solution of the composition (a3-4) obtained in Preparation Example 4 of the surface roughening material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to obtain the organic resin layer (A) (surface roughening layer) was formed.

<Example 5>

The solution of the composition (b3-1) obtained in Preparation Example 1 of the organic hard mask material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer) having a thickness of 150 nm. On the obtained organic resin layer (B) (organic hard mask layer), the solution of the composition (a3-5) obtained in Preparation Example 5 of the surface roughening material was applied to the substrate with a spin coater, and baked at 240° C. for 1 minute to obtain the organic resin layer (A) (surface roughening layer) was formed.

<Example 6>

The solution of the composition (b3-1) obtained in Preparation Example 1 of the organic hard mask material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer) having a thickness of 150 nm. On the obtained organic resin layer (B) (organic hard mask layer), the solution of the composition (a3-6) obtained in Preparation Example 6 of the surface roughening material was applied to the substrate with a spin coater, and baked at 240° C. for 1 minute to obtain the organic resin layer (A) (surface roughening layer) was formed.

<Example 7>

The solution of the composition (b3-1) obtained in Preparation Example 1 of the organic hard mask material was applied to the substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer) having a thickness of 150 nm. On the obtained organic resin layer (B) (organic hard mask layer), the solution of the composition (a3-7) obtained in Preparation Example 7 of the surface roughening material was applied to the substrate with a spin coater, and baked at 240° C. for 1 minute to obtain the organic resin layer (A) (surface roughening layer) was formed.

<Example 8>

The solution of the composition (a3-1) obtained in Preparation Example 1 of the surface roughening material was applied to the substrate with a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (A) (surface roughening layer).

<Comparative Example 1>

The solution of the composition (b3-1) obtained in Organic Hard Mask Material Preparation Example 1 was applied to a substrate by a spin coater, and baked at 240° C. for 1 minute to form an organic resin layer (B) (organic hard mask layer).

[Evaluation of surface roughness]

The wafers with the surface roughening layer obtained in Examples 1 to 8 were etched using RIE-10NR (manufactured by Samco Inc.). By using O ₂ gas as the etching gas, etching was performed for 90 seconds in Examples 1 to 7, and by etching for 60 seconds in Examples 8 and 1, only organic components of the surface roughening layer were preferentially etched. In Examples 1 to 7, the surface roughening layer was formed by etching the organic hard mask layer.

The shape of the obtained organic resin layer (A) or the surface roughened layer formed of the organic resin layer (A) and the organic resin layer (B) was observed using a scanning electron microscope (Hitachi S-4800) (refer to FIGS. 1 to 5). ).

Similarly, the shape of the surface roughening by only the organic resin layer (B) was observed (FIG. 6).

[Not TEOS processing evaluation]

The wafer on which the surface roughening layer of the organic resin layer (A) and the organic resin layer (B) obtained in Example 1 was formed was etched using RIE-10NR (manufactured by Samco Inc.). By etching for 90 seconds using O ₂ gas as an etching gas, only the organic components of the surface roughening layer were preferentially etched, and the organic hard mask layer was again etched to form the surface roughening layer. Subsequently, the surface roughening layer is etched for 180 seconds using C ₄ F ₈ /Ar/O ₂ gas as an etching gas to process the lower TEOS (SiO ₂ film by hydrolysis-condensation product of tetraethoxysilane). did

The shape of the obtained substrate was observed using a scanning electron microscope (Hitachi S-4800) (refer to FIGS. 7 to 8).

Industrial Applicability

Through the present invention, a novel method of roughening the surface of a substrate is provided. In particular, since the method of the present invention can use a layer in which an inorganic material and an organic material are mixed on a substrate, the oxygen gas or an acidic aqueous solution is applied to the surface of the substrate by using the etching rate difference between the oxygen gas or the acidic aqueous solution of the inorganic material and the organic material. An etched portion and a non-etched surface roughening layer can be formed, and again using the surface roughening layer as a mask, the substrate surface is roughened by etching with a gas such as oxygen gas or fluorine-based gas or an acidic aqueous solution, for example Fine irregularities can be formed on the substrate. In addition, by using these properties, it can be applied to a light extraction layer such as an LED.

Claims (15)

A composition (b3) containing an organic resin (b2) is applied on a substrate or on a layer above the substrate, followed by drying and curing to form an organic resin layer (B), and again inorganic particles on the organic resin layer (B) A first step of forming an organic resin layer (A) by applying a composition (a3) containing (a1) and an organic resin (a2), drying and curing;
a second step of roughening the surface of the same substrate by etching from above the substrate;
The organic resin layer (A) contains the inorganic particles (a1) in a ratio of 5 to 50 parts by mass relative to 100 parts by mass of the organic resin (a2),
A surface roughening method of using a novolak resin as the organic resin (b2).
According to claim 1,
The etching is performed at least once, of which at least one etching is gas etching using an oxygen-based gas.
According to claim 1,
The etching is a surface roughening method that is wet etching with an acidic aqueous solution.
According to claim 1,
The inorganic particle (a1) is a surface roughening method of a metal oxide particle having an average particle diameter of 5 to 1000 nm.
According to claim 1,
The composition (a3) is a surface roughening method comprising a silica sol in which silica is dispersed in an organic solvent as inorganic particles (a1) and a solution of an organic resin (a2).
delete According to claim 1,
The organic resin (a2) has a repeating unit structure comprising a functional group consisting of a hydroxyl group, a carboxyl group, an amino group, or a combination thereof.
According to claim 1,
A surface roughening method in which etching is performed until forming in the range of 0.1 to 20 with an aspect ratio of a hole expressed by (height)/(diameter) formed on the substrate.
9. The method according to any one of claims 1 to 5, 7 and 8,
The surface roughening method wherein the organic resin layer (A) is a layer having a film thickness of 0.001 to 10 μm.
delete delete According to claim 1,
The surface roughening method wherein the organic resin layer (B) is a layer having a film thickness of 0.001 to 10 μm.
9. The method according to any one of claims 1 to 5, 7 and 8,
The composition (a3) further comprises a crosslinking agent and a crosslinking catalyst.
9. The method according to any one of claims 1 to 5, 7 and 8,
The surface roughening layer formed is a surface roughening method that is a light extraction layer of an LED.
According to claim 1,
The composition (b3) further comprises a crosslinking agent and a crosslinking catalyst.

Images