KR100920886B1 - Developable composition for preparing organic antireflection film and organic antireflection film foremd using the composition - Google Patents

Abstract

The present invention includes a diol or a polyol compound containing at least two quaternary alkyl groups substituted with hydroxy groups as an acid decomposition type thermal crosslinking agent, so that the uniformity of the pattern in the fine pattern formation process of the photoresist during the lithography process of the semiconductor device. The present invention relates to an organic antireflection film composition capable of improvement and process simplification and an organic antireflection film formed therefrom.

By using the composition according to the present invention, the lower anti-reflective film is developed and patterned together with the photosensitive agent (photoresist) in the developing process for forming the photoresist pattern, thereby effectively omitting the process of removing the anti-reflective film.

Organic anti-reflective coating, development, acid decomposition type thermal crosslinking agent, diol or polyol compound

Description

DEVELOPABLE COMPOSITION FOR PREPARING ORGANIC ANTIREFLECTION FILM AND ORGANIC ANTIREFLECTION FILM FOREMD USING THE COMPOSITION

The present invention relates to a developable composition for forming an organic anti-radiation film and use thereof, and more particularly to a diol or polyol compound containing at least two quaternary alkyl groups substituted with hydroxy groups as an acid decomposition type thermal crosslinking agent. The present invention relates to a composition for forming an organic antireflection film and an organic antireflection film formed therefrom, capable of improving the uniformity of the pattern and simplifying the process in the fine pattern formation step of the photoresist during the lithography process of the semiconductor device.

In the ultrafine pattern forming step of the semiconductor manufacturing process, standing wave and reflective notching due to the optical properties of the lower layer or the thickness variation of the photoresist film formed thereon, and diffracted and reflected light from the lower layer. Inevitably, variations in the CD (critical dimension) of the photoresist pattern occur.

Therefore, a method of preventing light reflection in the lower layer is introduced by introducing a film that absorbs light well in the wavelength range of light used as an exposure source between the lower layer and the photoresist film, and the film used for this is an antireflection film.

The anti-reflection film may be classified into an inorganic anti-reflection film and an organic anti-reflection film according to the type of material used. In particular, in recent years, in the ultrafine pattern formation process, an organic antireflection film is mainly used, and the composition for forming such an organic antireflection film should generally satisfy the following requirements.

(1) After coating the antireflection film, in the step of coating the photoresist film thereon, the antireflection film should not be dissolved by the solvent of the photoresist. To this end, in the process of coating the antireflection film composition and baking to laminate the antireflection film, the antireflection film should be designed to have a crosslinked structure, and other chemicals should not be generated as a by-product.

(2) In order to suppress the diffuse reflection from the lower layer, it should contain a material with high absorbance in the wavelength range of the exposure light source.

(3) Finally, in the step of laminating the antireflection film composition, a catalyst for activating the crosslinking reaction is required.

In order to satisfy such requirements, conventionally, a crosslinking agent for allowing the antireflection film to have a crosslinking structure, an optical absorber having a large absorbance in the wavelength range of an exposure light source, and an organic acid containing a thermal acid generator as a catalyst for activating the crosslinking reaction. An antireflection film composition is used.

However, when the anti-reflection film is formed using the organic anti-reflection film composition according to the prior art, the etching rate is low, there is a problem that the anti-reflection film is difficult to remove by the normal etching conditions. In particular, due to such low etching rate and etching rate, an excessive etching is required to remove the anti-reflection film later, but the lower layer is damaged and the photoresist layer is damaged, resulting in deterioration of reliability of the final device. It was.

In order to prevent this, the method of thickening the photoresist layer is disadvantageous because it adversely affects the formation of fine patterns. Therefore, while developing an antireflection film and a composition thereof that can effectively remove diffuse reflection and standing waves in the lower layer, and can be easily removed by ordinary etching conditions due to the large etching rate and etching rate, the antireflection film is still removed. It is true that a process is needed to achieve this.

In this regard, Korean Patent Laid-Open Publication No. 2004-9384 and Korean Patent Publication No. 10-703007 disclose an organic bottom anti-reflective composition soluble in a photoresist developer. According to the above documents, a process for removing the anti-reflection film is not necessary separately, which is efficient in the pattern forming process. However, there is still an urgent need in the art for the development of new organic antireflection films and compositions thereof, and the present invention has been completed under these technical requirements.

An object of the present invention is to provide a new developable composition for forming an organic antireflection film, which can be developed together with a photoresist (photoresist) to omit the step for removing the antireflection film.

Another object of the present invention is to provide an organic antireflection film formed using the composition.

One aspect of the present invention for achieving the above object is a) a copolymer comprising a monomer represented by the formula (1) and a monomer absorbing a short wavelength source of less than 248nm; b) an acid decomposition type thermal crosslinking agent, the diol or polyol compound containing at least two quaternary alkyl groups substituted with a hydroxy group; c) acid generators; And d) relates to a composition for forming an organic antireflection film comprising a solvent.

[Formula 1]

In Chemical Formula 1,

R ₆ is hydrogen or methyl,

X is a halogen atom or-(CH ₂ ) _a -Y, wherein Y is an epoxy group, glycidyl group or amine group, and a is an integer of 0 to 10.

According to one embodiment, the diol or polyol compound is a compound represented by formula (2).

[Formula 2]

In Chemical Formula 2,

R ₁ is a C1-C10 alkylene group, a C1-C10 alkoxyalkylene group, a C6-C20 aromatic group, an ester group, a carbonate group, a carbonyl group, an amine group or an amide group unsubstituted or substituted with a functional group represented by the following formula (3): ego,

R ₂ , R ₃ , R ₄ , and R ₅ are each independently substituted or unsubstituted C 1 to C 10 alkyl group, C 1 to C 10 alkoxyalkyl group, C 6 to C 20 aromatic group, ester group, carbo It is a silyl group, an amine group, or an amide group.

[Formula 3]

In Chemical Formula 3,

R <_7> , R <_8> is respectively independently C1-C10 alkyl group, C1-C10 alkoxyalkyl group, C6-C20 aromatic group, ester group, carbonyl group, amine group, or amide group.

According to another embodiment, the compound represented by Formula 2 is 2,2,4,4-dimethyldihydroxy butane, 2,2,5,5-dimethyldihydroxypentane, 2,2,6,6- It is 1 type, or 2 or more types chosen from the group which consists of dimethyl dihydroxy heptane and 2,2,4,4-diethyl dihydroxy butane.

According to another embodiment, X in formula 1 is a halogen atom, in particular Cl.

According to another embodiment, the monomer absorbing the short wavelength exposure source of 248 nm or less is a monomer represented by Formula 4.

[Formula 4]

In Chemical Formula 4,
R ₆ is hydrogen or methyl,

Z is an anthracene group, a benzene group, a phenyl group, a naphthalene group, a naphthacene group, a pentacene group or an anthracenyl benzyl group,

b is an integer of 0-10.

According to another embodiment, the copolymer of a) further comprises a monomer represented by the formula (5).

[Formula 5]

In Chemical Formula 5,
R ₆ is hydrogen or methyl,

A is hydrogen, an alkyl group having 1 to 10 carbon atoms, an ester group, an acetal group, an epoxy group, a hydroxyl group or an amine group.

According to another embodiment, the copolymer of a) has a weight average molecular weight of 2,000 to 100,000.

According to another embodiment, the composition comprises a) 0.1 to 50 wt% of the copolymer, b) 0.1 to 25 wt% of the diol or polyol compound, 0.1 to 10 wt% of the c) acid generator, and d ) 30 to 99.5% by weight of the solvent.

Another aspect of the present invention for achieving the above object is an organic antireflection film formed using the composition.

According to one embodiment, the organic antireflection film comprises a crosslinking end represented by the formula (6).

[Formula 6]

In Chemical Formula 6,

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are each as defined above.

When the anti-reflection film is formed using the composition for forming an organic anti-reflection film according to the present invention, since the anti-reflection film may be selectively developed together with the photoresist (photoresist) only in the exposed areas during patterning, the process for removing the anti-reflection film may be omitted. In this case, it is possible to easily form a fine pattern, and eliminate the problems caused during the anti-reflection film removal process.

Hereinafter, the configuration and operation of the present invention in more detail.

The present invention,

a) a copolymer comprising a monomer represented by the following Chemical Formula 1 and a monomer absorbing a short wavelength exposure source of 248 nm or less;

b) an acid decomposition type thermal crosslinking agent, the diol or polyol compound containing at least two quaternary alkyl groups substituted with a hydroxy group;

c) acid generators; And

d) It provides a composition for forming an organic antireflection film comprising a solvent.

[Formula 1]

In Chemical Formula 1,

R ₆ is hydrogen or methyl,

X is a halogen atom or-(CH ₂ ) _a -Y, wherein Y is an epoxy group, glycidyl group or amine group, and a is an integer of 0 to 10.

The composition of the present invention is a copolymer having a crosslinked moiety (the monomer represented by Formula 1) and a chromophore (monomer absorbing a short wavelength exposure source of 248 nm or less represented by the following Formula 4), that is, each unit polymer Crosslinking with an acid decomposition thermal crosslinking agent forms a high molecular weight polymer (organic antireflection film). At this time, the crosslinked portion between each unit polymer has a characteristic of being easily separated by an acid, and is decomposed into a polar unit polymer having a low molecular weight and melting in a developer by an acid generated by an acid generator during exposure, thereby developing a pattern. It is washed away by the developer along with the photosensitizer. Therefore, in the step of forming the ultrafine pattern of the photoresist using the composition of the present invention, there is no need to proceed with the existing anti-reflection film removing process, and therefore, it is efficient in the manufacturing process.

As the crosslinking agent for crosslinking the copolymer contained in the composition in the present invention, an acid decomposition type thermal crosslinking agent crosslinked by heat and decrosslinked (decomposed) by acid is used.

Specifically, a diol or polyol compound containing at least two quaternary alkyl groups substituted with hydroxy groups is used as the acid decomposition type thermal crosslinking agent.

Preferably, the diol or polyol compound is a compound represented by the following formula (2).

[Formula 2]

In Chemical Formula 2,

R ₁ is a C1-C10 alkylene group, a C1-C10 alkoxyalkylene group, a C6-C20 aromatic group, an ester group, a carbonate group, a carbonyl group, an amine group or an amide group unsubstituted or substituted with a functional group represented by the following formula (3): ego,

R ₂ , R ₃ , R ₄ , and R ₅ are each independently substituted or unsubstituted C 1 to C 10 alkyl group, C 1 to C 10 alkoxyalkyl group, C 6 to C 20 aromatic group, ester group, carbo It is a silyl group, an amine group, or an amide group.

[Formula 3]

In Chemical Formula 3,

R <_7> , R <_8> is respectively independently C1-C10 alkyl group, C1-C10 alkoxyalkyl group, C6-C20 aromatic group, ester group, carbonyl group, amine group, or amide group.

For example, the compound represented by Formula 2 is 2,2,4,4-dimethyldihydroxy butane, 2,2,5,5-dimethyldihydroxypentane, 2,2,6,6-dimethyldi Hydroxy hexane, 2,2,4,4-diethyl dihydroxybutane, and the like, and these may be used alone or in combination of two or more thereof.

The quaternary alkyl moiety substituted with the hydroxy group contained in the diol or polyol compound is easily decomposed by an acid and easily developed by a developer.

The acid decomposition type thermal crosslinking agent is included in the content of 0.1 to 25% by weight, preferably 5 to 10% by weight of the composition of the present invention. When the acid decomposition type thermal crosslinking agent is included in the above range, it exhibits proper crosslinking performance and is good in that the developing speed is good in the developer.

The copolymer contained in the composition of the present invention is a polymer obtained by polymerizing a monomer represented by the following formula (1) and a monomer absorbing a short wavelength exposure source of 248 nm or less.

[Formula 1]

In Chemical Formula 1,

R ₆ is hydrogen or methyl,

X is a halogen atom or-(CH ₂ ) _a -Y, wherein Y is an epoxy group, glycidyl group or amine group, and a is an integer of 0 to 10.

At this time, the monomer represented by the formula (1) is a portion that is combined with the acid-decomposition type thermal crosslinking agent to form a crosslinking stage, X is bonded to the hydroxyl group of the crosslinking agent crosslinking reaction by heat and at the same time to the catalytic action of the acid Corresponds to the acid-decomposed protecting group which is decrosslinked by. Preferred examples of such X are halogen atoms, in particular Cl.

The monomer absorbing the short wavelength exposure source of 248 nm or less is a portion corresponding to the chromophore, and includes an acrylate monomer or a methacrylate monomer containing a functional group such as anthracene capable of absorbing light of 248 nm or less. Specifically, the monomer absorbing the short wavelength exposure source of 248 nm or less is a monomer represented by the following formula (4).

[Formula 4]

In Chemical Formula 4,
R ₆ is hydrogen or methyl,

Z is an anthracene group, a benzene group, a phenyl group, a naphthalene group, a naphthacene group, a pentacene group or an anthracenyl benzyl group,

b is an integer of 0-10.

At this time, in the general formula (4), preferably Z is an anthracene group.

The monomer represented by Formula 4 may be prepared by ester-reacting an alkyl alcohol having a functional group such as an anthracene group with acrylic acid, or may be prepared by esterifying an alkyl alcohol having a functional group such as an anthracene group with methacrylic acid.

In addition, the copolymer may be obtained by further polymerizing an auxiliary monomer having another functional group that may help light absorption or crosslinking, if necessary. As the auxiliary monomer, monomers commonly used in the art may be used without limitation, including, for example, ethylenically unsaturated monomers including carboxylic acid.

Specifically, the monomer represented by the following formula (5) can be used as the auxiliary monomer.

[Formula 5]

In Chemical Formula 5,
R ₆ is hydrogen or methyl,

A is hydrogen, an alkyl group having 1 to 10 carbon atoms, an ester group, an acetal group, an epoxy group, a hydroxyl group or an amine group.

The copolymer of the present invention may be prepared by a general radical polymerization method using the monomer represented by the formula (1), the monomer absorbing the short wavelength exposure source of 248 nm or less, and optionally the auxiliary monomer.

For example, the monomer represented by Formula 1 (e.g., acryloyl chloride) and the monomer (e.g., anthracene methyl methacrylate) absorbing the short wavelength exposure source of 248 nm or less are dissolved in a suitable organic solvent such as ethyl acetate. A copolymer of the present invention can be obtained by adding a common polymerization initiator, for example, azobisisobutyronitrile (AIBN), and then reacting at 50 to 100 ° C. for 1 to 12 hours in a nitrogen atmosphere.

Such a copolymer may be a random copolymer, a block copolymer or a graft copolymer, and the like, and a preferable example thereof may be a copolymer of the following structural formula 1, and a more preferable example may be a copolymer of the following structural formula 2.

[Formula 1]

In Formula 1, X, A, R ₆ are the same as defined above,

l, m, n are the mole percent of each repeating unit relative to the total repeating unit, l is 0.1-70 mol%, m is 0.1-70 mol%, n is 0-50 mol%, and l + m + n = 100 mol%.

[Formula 2]

In formula 2, R ₆ , l, m, n are as defined above, respectively.

On the other hand, the weight average molecular weight of the copolymer can be appropriately adjusted by those skilled in the art according to the development conditions of the developer for photoresist, but generally it is preferably in the range of 2,000 to 100,000, more preferably 5,000 to 10,000. The use of a copolymer having a weight average molecular weight in the above range can ensure an appropriate level of crosslinking performance and can be easily removed during development.

In addition, such a copolymer is included in the composition of the present invention in an amount of 0.1 to 50% by weight, preferably in an amount of 0.5 to 10% by weight, more preferably 1 to 5% by weight. When the copolymer is included in the above range, it is possible to ensure the coating thickness and smoothness that are typically required in the semiconductor manufacturing process, it is good in that it can stably absorb the excess light.

The acid generator included in the composition of the present invention may use a photo acid generator that reacts with light to generate an acid.

Examples of the photoacid generator include diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxyphenyl triflate, diphenyl paratoluenyl triflate, diphenyl Phenylparaisobutylphenyl triflate, diphenylpara-t-butylphenyl triflate, triphenylsulfonium hexafluoro phosphate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsul Phosphon triflate, dibutyl naphthylsulfonium triflate, and the like.

Each of these photoacid generators may be used alone or in combination of two or more thereof, and is included in the composition of the present invention 0.1 to 10% by weight, preferably 0.5 to 5% by weight. If the amount of the photoacid generator is less than 0.1% by weight, the acid generation at the exposed part is insufficient, and the cross-linking (decomposition) phenomenon due to the acid is not sufficient, so that the developer cannot be sufficiently removed in the developing solution. This causes undercut phenomenon of the resist pattern.

The solvent used in the composition of the present invention is used to dissolve the acid decomposition type thermal crosslinking agent, the copolymer, and the acid generator, and to set the viscosity of the composition.

As the solvent, a conventional organic solvent may be used, and examples thereof include butyrolactone, cyclopentanone, cyclohexanone, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methyl pyrrolidone, and tetra Hydrofurfural alcohol (tetrahydro furfural alchohol), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate or mixtures thereof may be used, more preferably propylene glycol monomethyl ether , Propylene glycol monomethyl ether acetate, ethyl lactate or mixtures thereof can be used.

The amount of the solvent may vary depending on the thickness of the organic antireflection film to be formed on the substrate and the viscosity to be set. For this reason, since the viscosity of the composition of the present invention must be relatively increased in order for the organic antireflection film to have a high thickness, the amount of solvent used is reduced. On the other hand, since the viscosity of the composition must be relatively low in order to form an organic antireflection film on the substrate to have a low thickness, the amount of solvent used is increased. Specifically, the amount of the solvent used is 30 to 99.5% by weight, preferably 50 to 99% by weight of the composition of the present invention.

The composition for forming an organic antireflection film of the present invention may further include other additives such as other crosslinking agents, crosslinking reaction accelerators, light absorbing agents, lower alcohols, and acid defoaming agents.

The additive is preferably included in an amount of 0.01 to 10% by weight in the composition of the present invention.

The crosslinking agent is for further improving the curability of the organic antireflection film. Preferably, a crosslinking agent that crosslinks a monomeric crosslinking agent, more preferably a polymer having a hydroxyl group, an amide group, a carboxyl group, or a thiol group can be used. Preferred examples of the crosslinking agent include hydroxymethylmelamine, alkoxymethylmelamine, urea-formaldehyde resin, benzyl ether, benzyl alcohol, epoxy compound, phenolic resin, isocyanate, blocking equalizer, alkylol acrylamide, methacrylamide and these And mixtures thereof.

The crosslinking reaction promoter is for promoting the crosslinking reaction and increasing the efficiency of the reaction. Preferably, a thermal acid generator may be used, and specifically, 2-hydroxyhexyl p-toluenesulfonate There is.

The light absorbing agent absorbs the exposure reflected from the etched layer of the semiconductor substrate during the photolithography process, and serves to prevent undercutting, notching, and the like, which may occur in the photoresist pattern. As such a light absorbing agent, those commonly used may be used without limitation, and examples thereof include 9-anthracene methanol, 9-anthracene ethanol, alizarin, quinizarine, primoline, 9-anthracene carboxymethyl triethoxysilane and 9-anthracene. Carboxy-methyl triethoxysilane, 9-anthracene methanol, 2-hydroxy-4- (3-triethoxysilylpropoxy) -dephenyl ketone, etc. are mentioned.

Other additives such as lower alcohols, acids, surface leveling agents, adhesion promoters, antifoaming agents and the like may be used in the formation of the organic anti-reflective coating, and those commonly known to those skilled in the art may be used.

The present invention also provides an organic antireflection film formed using the organic antireflection film composition.

The organic anti-reflection film is a step of applying the organic anti-reflective coating composition on the etched layer; And it may be prepared by the step of thermosetting the applied organic anti-reflective coating composition.

At this time, the step of applying the organic anti-reflective coating film composition on the etched layer may be performed by a conventional method such as spin coating, roller coating.

In addition, the step of thermosetting the composition for forming an organic antireflection film may be performed by heating the applied composition in a device such as a hot plate, a convection oven.

The thermosetting step may be performed at a high temperature such that the organic antireflection film formed by curing is not dissolved in an organic solvent, a water-soluble alkaline developer, or the like included in the photoresist composition in a process of forming a photoresist pattern. It may be carried out at ℃ to 250 ℃. The solvent contained in the composition for forming an organic antireflection film may be sufficiently removed when the heating temperature is 70 ° C. or higher, the crosslinking reaction may be sufficiently performed, and the composition and the composition for forming an organic antireflection film when the heating temperature is 250 ° C. or less There is no fear that the antireflection film will be chemically unstable.

The organic antireflective film thus formed includes a crosslinked end represented by the following Chemical Formula 6:

[Formula 6]

In Chemical Formula 6,

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are each as defined above.

Meanwhile, a method of forming a pattern using the composition for forming an organic antireflection film according to the present invention will be described below.

An organic antireflection film is formed on the etching target, ie, the substrate or the thin film, using the composition of the present invention. At this time, the description of the organic anti-reflection film forming process is the same as described above and will be omitted.

The photoresist is then coated on the formed organic antireflection film to form a photoresist film. Here, as the photoresist, any one conventionally used in the art may be used without limitation, for example, i) a positive photoresist containing a naphthoquinone diazide compound and a novolak resin, and ii) by exposure. In the presence of a chemically amplified positive photoresist containing an acid generator capable of dissociating an acid, a compound which decomposes in the presence of an acid to increase its solubility in an aqueous alkali solution, and an alkali-soluble resin, and iii) an acid generator and an acid. And chemically-amplified positive photoresists containing an alkali-soluble resin having a group capable of degrading to give a resin which increases solubility in an aqueous alkali solution.

Subsequently, a first baking process of heating the substrate on which the photoresist film is formed is performed. The first baking process may be performed at a temperature of about 90 to 150 ℃. The adhesion of the photoresist film to the organic antireflection film is increased by performing the first baking process.

The photoresist film is then selectively exposed. For example, an exposure process for exposing the photoresist film is described as follows: That is, an exposure mask on which a predetermined pattern is formed is placed on a mask stage of an exposure apparatus, and the exposure mask is aligned on the photoresist film. do. Subsequently, by irradiating the mask with light, a predetermined portion of the photoresist film formed on the substrate is selectively reacted with the light transmitted through the exposure mask. Examples of the light that can be used in the exposure step include KrF lasers, ArF lasers, and the like having a wavelength of 248 nm or less. At this time, the exposure reaction also occurs in the organic antireflection film existing under the photoresist film.

The photoresist film of the exposed portion is relatively hydrophilic than the photoresist film of the non-exposed portion. Accordingly, the photoresist film of the exposed portion and the non-exposed portion have different solubility, and the organic antireflection film also has different solubility between the exposed portion and the unexposed portion.

Subsequently, a second baking process is optionally performed on the substrate. The second baking process may be performed at a temperature of about 90 to 180 ℃. By performing the second baking process, the photoresist film and the organic anti-reflection film corresponding to the exposed region are in a state of being easily dissolved in a specific solvent (developing solution).

Subsequently, a photoresist pattern and an organic antireflection film pattern are simultaneously formed by dissolving and removing the photoresist film corresponding to the exposed area and the organic antireflection film corresponding to the exposed area using a developing solution. Specifically, the photoresist pattern and the organic antireflection film pattern are completed by sequentially dissolving and removing the photoresist film and the organic antireflection film corresponding to the exposed area using a developer such as tetramethylammonium hydroxide (TMAH). do.

Therefore, a separate etching process for forming the anti-reflection film pattern after the photoresist pattern forming process is not required.

Finally, the exposed thin film or substrate is etched by applying the photoresist pattern as an etching mask. As a result, the thin film or substrate is formed in a thin film pattern.

Hereinafter, the present invention will be described in more detail with reference to specific preparation examples and examples. However, the following Preparation Examples and Examples are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

[Production of Copolymer]

Production Example  One

In a reactor equipped with a reflux condenser, 22 g of acryloyl chloride and 25 g of anthracene methyl methacrylate were dissolved in 100 g of ethyl acetate, 2.37 g of 2,2'-azobisisobutyronitrile (AIBN) was added, followed by 70 ° C. The reaction was carried out under nitrogen atmosphere for 5 hours at. After the reaction was completed, the mixture was cooled to room temperature, and a precipitate was formed in 1 liter of anhydrous hexane to remove unreacted impurities. The precipitate was filtered through a filter and dried at room temperature in a vacuum oven for 24 hours to obtain 25 g of a polymer powder represented by the following formula (7). The weight average molecular weight of this polymer powder measured by GPC was 12,000.

[Formula 7]

In Formula 7, l is 70 mol%, m is 30 mol%.

Production Example  2

In a reactor equipped with a reflux condenser, 13 g of acryloyl chloride, 25 g of anthracene methyl methacrylate, and 9 g of methyl methacrylate were dissolved in 100 g of ethyl acetate, and 2.37 g of 2,2'-azobisisobutyronitrile (AIBN) Was added and reacted at 70 ° C. for 5 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was cooled to room temperature, and a precipitate was formed in 1 liter of anhydrous hexane to remove unreacted impurities. The precipitate was filtered through a filter and then dried at room temperature in a reduced pressure oven for 24 hours to obtain 25 g of a polymer powder represented by the following formula (8). The weight average molecular weight of this polymer powder measured by GPC was 12,500.

[Formula 8]

In Formula 8, l is 40 mol%, m is 30 mol%, n is 30 mol%.

[abandonment Antireflection film  Preparation of Forming Composition]

Example  One

10 g of the material prepared in Preparation Example 1 was dissolved in 300 g of propylene glycol methyl ether acetate (PGMEA), and as an acid decomposition type thermal crosslinking agent, 2 g of 2,2,4,4-dimethyldihydroxybutane, a photoacid generator, 0.5 g of triphenylsulfonium triplerate salt represented by 9 was added thereto and dissolved under stirring for 12 hours in a nitrogen atmosphere to prepare a composition for forming an antireflection film.

[Formula 9]

Example  2

The same procedure as in Example 1 was carried out except that the material prepared in Preparation Example 2 was used.

Comparative example  One

In a reactor equipped with a reflux condenser, 50 g of anthracene methyl methacrylate, 27 g of hydroxyethyl methacrylate, 21 g of methyl methacrylate, and 4.7 g of AIBN were dissolved in 285 g of ethyl lactate, followed by reaction at 70 ° C. under a nitrogen atmosphere for 5 hours. I was. After the reaction was completed, the reaction mixture was cooled to room temperature, and precipitated in 1 liter of anhydrous hexane to remove unreacted impurities. The precipitate was filtered through a filter and then dried in a reduced pressure oven for 24 hours to obtain 75 g of a polymer powder represented by the following formula (10). The weight average molecular weight of this polymer powder measured by GPC was 15,200.

[Formula 10]

In Formula 10, l is 30 mol%, m is 35 mol%, n is 35 mol%.

An organic antireflection film-forming composition was obtained in the same manner as in Example 1, except that glycol uril (Glycoluril) was used as the copolymer and the crosslinking agent prepared above.

[ Experimental Example : Pattern formation and pattern characteristic measurement]

The antireflection film-forming compositions obtained in Examples 1 and Comparative Example 1 were coated with a thickness of 60 nm on a silicon wafer and heated at 120 ° C. for 180 seconds to form an antireflection film. The acetal-type photoresist was spin-coated at 600 nm on the formed antireflection film, exposed using Nikon's KrF exposure equipment, and heated again at 120 ° C. for 90 seconds. The pattern was obtained by developing the exposed wafer using the developing solution of 2.38 weight% of TMAH.

The pattern obtained using the composition of Example 1 is shown in FIG. 1, and the pattern obtained using the composition of Comparative Example 1 is shown in FIG. As can be seen from the drawings, it can be seen that the pattern obtained using the composition of the present invention is excellent without undercutting or putting, and the lower anti-reflection film is removed by the developer.

1 is a cross-sectional photograph of a photoresist pattern obtained using the composition of Example 1 by SEM (electron scanning microscope), in which a antireflection film is removed by a developer. In the exposed part, the antireflection film was removed, and in the unexposed part (the lower part of the pattern), the antireflection film remained as it is.

2 is a cross-sectional photograph of a photoresist pattern obtained using the composition of Comparative Example 1 by SEM (electron scanning microscope). It can be seen that the antireflection film layer remains in both the exposed and unexposed portions.

Claims (10)

a) a copolymer comprising a monomer represented by the following Chemical Formula 1 and a monomer absorbing a short wavelength exposure source of 248 nm or less; b) an acid decomposition type thermal crosslinking agent, the diol or polyol compound containing at least two quaternary alkyl groups substituted with a hydroxy group; c) acid generators; And d) an organic antireflective coating composition comprising a solvent: [Formula 1]

In Chemical Formula 1, R ₆ is hydrogen or methyl, X is a halogen atom or-(CH ₂ ) _a -Y, wherein Y is an epoxy group, glycidyl group or amine group, and a is an integer of 0 to 10. The method according to claim 1, The diol or polyol compound is a composition characterized in that the compound represented by the formula (2): [Formula 2]

In Chemical Formula 2, R ₁ is a C1-C10 alkylene group, a C1-C10 alkoxyalkylene group, a C6-C20 aromatic group, an ester group, a carbonyl group, an amine group, or an amide group, unsubstituted or substituted with a functional group of Formula 3, R ₂ , R ₃ , R ₄ , and R ₅ are each independently substituted or unsubstituted C 1 to C 10 alkyl group, C 1 to C 10 alkoxyalkyl group, C 6 to C 20 aromatic group, ester group, carbo It is a silyl group, an amine group, or an amide group. [Formula 3]

In Chemical Formula 3, R <_7> , R <_8> is respectively independently C1-C10 alkyl group, C1-C10 alkoxyalkyl group, C6-C20 aromatic group, ester group, carbonyl group, amine group, or amide group. The method according to claim 2, Compound represented by the formula (2) is 2,2,4,4-dimethyldihydroxy butane, 2,2,5,5-dimethyldihydroxypentane, 2,2,6,6-dimethyldihydroxy hexane, 1, 2 or more types selected from the group consisting of 2,2,4,4-diethyldihydroxybutane. The method according to claim 1, In Formula 1, X is a halogen atom, characterized in that the composition. The method according to claim 1, The monomer absorbing the short wavelength light source of less than 248nm is a composition characterized in that the monomer represented by the following formula (4): [Formula 4]

In Chemical Formula 4, R ₆ is hydrogen or methyl, Z is an anthracene group, a benzene group, a phenyl group, a naphthalene group, a naphthacene group, a pentacene group or an anthracenyl benzyl group, b is an integer of 0-10. The method according to claim 1, The copolymer of a) is characterized in that it further comprises a monomer (co-monomer) represented by the formula (5): [Formula 5]

In Chemical Formula 5, R ₆ is hydrogen or methyl, A is hydrogen, an alkyl group having 1 to 10 carbon atoms, an ester group, an acetal group, an epoxy group, a hydroxyl group or an amine group. The method according to claim 1, The copolymer of a) is characterized in that the weight average molecular weight is 2,000 ~ 100,000. The method according to claim 1, The composition comprises a) 0.1 to 50 wt% of the copolymer, b) 0.1 to 25 wt% of the diol or polyol compound, 0.1 to 10 wt% of the c) acid generator, and d) 30 to 99.5 wt% of the solvent. Composition comprising a. An organic antireflection film formed using the composition according to any one of claims 1 to 8. The method according to claim 9, The organic anti-reflection film is an organic anti-reflection film comprising a cross-linked end represented by the formula (6): [Formula 6]

In Chemical Formula 6, R ₁ is a C1-C10 alkylene group, a C1-C10 alkoxyalkylene group, a C6-C20 aromatic group, an ester group, a carbonyl group, an amine group, or an amide group, unsubstituted or substituted with a functional group of Formula 3, R ₂ , R ₃ , R ₄ , and R ₅ are each independently substituted or unsubstituted C 1 to C 10 alkyl group, C 1 to C 10 alkoxyalkyl group, C 6 to C 20 aromatic group, ester group, carbo It is a nil group, an amine group, or an amide group, R ₆ is hydrogen or methyl. [Formula 3]

In Chemical Formula 3, R <_7> , R <_8> is respectively independently C1-C10 alkyl group, C1-C10 alkoxyalkyl group, C6-C20 aromatic group, ester group, carbonyl group, amine group, or amide group.

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