KR101186782B1 - Organic antireflective coating composition having excellent characteristic of gap filling and organic antireflective layer manufactured by the composition - Google Patents

Abstract

The organic antireflective coating composition includes a compound of the following formula. In the above formula, R is hydrogen or an alkyl group having 1 to 10 carbon atoms, an alcohol group having 1 to 10 carbon atoms, an alkylester group having 1 to 8 carbon atoms, a heteroalkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 3 to 14 carbon atoms. And m and n are numbers representing repeating units, respectively, and are values satisfying a relation of m + n = 1, 0.05 <m <0.95 and 0.05 <n <0.95.

Description

Organic antireflective coating composition having excellent buried properties and organic antireflective coating manufactured thereby {ORGANIC ANTIREFLECTIVE COATING COMPOSITION HAVING EXCELLENT CHARACTERISTIC OF GAP FILLING AND ORGANIC ANTIREFLECTIVE LAYER MANUFACTURED BY THE COMPOSITION}

An organic antireflection film is disclosed. More specifically, in the lithography process, an organic antireflection film composition capable of preventing reflection of reflected waves and standing waves and having excellent embedding characteristics, and an organic antireflection film produced thereby are disclosed.

Recently, due to the high integration of semiconductor devices, ultra-fine patterns of 0.10 microns or less are required for the manufacture of ultra-LSI, so that the exposure wavelength is further shortened in the g- and i-ray regions used in the prior art, and thus far-infrared and KrF A study on lithography using an excimer laser and an ArF excimer laser has attracted attention.

In lithography using KrF or ArF excimer lasers, pattern distortion caused by reflected waves and stationary waves has become a big problem. In order to solve this problem, an anti-reflection film is introduced between the photoresist and the substrate.

In order to overcome the pattern distortion caused by the reflected wave and the standing wave, the anti-reflection film must have absorption in specific light, have no intermixing with the photoresist, and have a faster etching rate than the photoresist.

In recent years, the use of copper has increased due to the resistance of wiring due to the miniaturization of patterns. The damascene process is actively being used to solve various problems that may occur due to the use of copper for patterning, and the use of the damascene process can further increase the chip density on the substrate. It also eliminates the need to etch metal layers that provide interconnects, enabling more densely located interconnects, and eliminating the need for gap-filling dielectric materials.

The damascene process includes a dual damascene process and a single damascene process. First, a method called a dual damascene process includes a via hole for connecting a lower layer at a lower portion of a wiring groove formed in an interlayer insulating layer. ), And the wiring groove and the via hole are simultaneously filled in the metal film to form the wiring to shorten the number of steps. In addition, a method of forming a buried wiring in the wiring groove after forming a metal plug in the via hole in advance is called a single damascene process.

In this damascene process, since most of the filling materials used to fill the wiring grooves contain no light absorbing material, the anti-reflective film having a large light absorbency on specific light is again used on the filling material. A layered process is used. However, a landfill material with sufficient light absorption and planarization properties can simplify the process.

Although these materials have been developed in landfills or anti-reflective films to date, sufficient anti-reflection films have not been developed in all functions. Therefore, there is a need for a material having sufficient light absorption properties and sufficient embedding properties such as no void, such as an organic bottom anti-reflective coating. In addition, there is an urgent need for research into a landfill agent having excellent planarization properties in the planarization process.

Provided is an organic antireflection film composition that can effectively absorb reflected light generated during exposure in a lithography process requiring fine pattern formation and has excellent embedding characteristics.

In addition, an organic anti-reflection film is provided, which allows for fast etching and reduces phenomena such as undercut and footing.

Organic antireflection film composition according to an embodiment of the present invention is 0.1 to 40% by weight of the copolymer represented by the formula (1), 0.1 to 40% by weight of the light absorber, 0.01 to 20% by weight of the thermal acid generator and 0.01 to 40% by weight of the curing agent Contains%

In the formula (1), R is hydrogen or an alkyl group having 1 to 10 carbon atoms, an alcohol group having 1 to 10 carbon atoms, an alkyl ester group having 1 to 8 carbon atoms, and an alkyl group having 1 to 8 carbon atoms Heteroalkyl or a cycloalkyl group having 3 to 14 carbon atoms, wherein m and n each represent a repeating unit, and m + n = 1, 0.05 <m <0.95 and 0.05 <n <0.95 The value satisfies the relation.

The organic antireflection film formed using the copolymer for the organic antireflection film and the light absorber can provide general solvent resistance and excellent embedding properties.

Therefore, in the ultra-fine pattern formation process using a 248nm light source, it has an excellent process window, so that an excellent pattern profile can be obtained regardless of the type of substrate. By simultaneously using a form of light absorber, it is possible to increase the buried effect and reduce the voids (void).

1 is a scanning electron micrograph in a state where an organic antireflection film is applied.
2 is a scanning electron micrograph in a state where an organic antireflection film is applied.
3 is a scanning electron micrograph in a state where an organic antireflection film is applied.

Embodiments described herein are provided to fully inform the scope of the invention to those skilled in the art to which the present invention pertains, and are to be understood as illustrative in all respects and not as limiting. Is only defined by the scope of the claims.

The composition for an organic antireflection film should satisfy the following requirements.

First, a material capable of absorbing light in the wavelength region of the exposure light source is included to prevent reflection of the lower layer.

Second, in the process of laminating the antireflection film and then laminating the photoresist, the antireflection film is dissolved and not destroyed by the solvent of the photoresist. To this end, the antireflection film is designed to be curable by heat, and in the antireflection film lamination process, the coating process is performed by a baking process to proceed with curing.

Third, the antireflective film is etched faster than the upper photoresist to reduce the loss of photoresist for etching the lower film layer.

Fourth, it has no reactivity with the upper photoresist. In addition, compounds such as amines and acids do not migrate to the photoresist layer. This is because it may cause the shape of the photoresist pattern, particularly footing or undercut.

Fifth, the optical properties suitable for various exposure processes according to various substrates, that is, to have an appropriate refractive index and absorption coefficient, and to improve the adhesion to the substrate and the photoresist.

Hereinafter, the organic antireflection film formed by curing the organic antireflection film composition and the organic antireflection film composition of the present invention will be described in detail.

The organic antireflection film composition may include a copolymer represented by Formula (1).

[Formula 1]

In formula (1), R is hydrogen or an alkyl group having 1 to 10 carbon atoms, an alcohol group having 1 to 10 carbon atoms, an alkyl ester group having 1 to 8 carbon atoms, a heteroalkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 3 to 14 carbon atoms And m and n are numbers representing repeating units, respectively, and satisfy a relational expression of m + n = 1, 0.05 <m <0.95 and 0.05 <n <0.95.

The copolymer represented by the formula (1) is a novolak (primary resin produced by an acidic catalyst during the production process of a phenolic resin in order to improve the problems when using a polymer-type landfill agent mainly used in the prior art) novolak) by using a polymer and a ring-opened unhydride absorbent at the same time is characterized in that to improve the flatness and reduce the voids when buried.

The organic antireflective coating composition according to one side of the present invention may include 0.1 to 40% by weight of a light absorber including at least one or more of the compounds represented by Formulas (2) to (4).

In Formulas (2) to (4), X is a cyclic compound having 3 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, diaryl ether having 12 to 20 carbon atoms, and having 12 to 20 carbon atoms. At least one compound selected from the group consisting of diaryl sulfide, diaryl sulfoxide of 12 to 20 carbon atoms, and diaryl keton of 12 to 20 carbon atoms, R ₁ is carbon number It is an aryl group of 6-14, Formula (2) and Formula (3) are isomers mutually. In addition, the light absorber comprises a compound represented by the formula (2) and formula (3) in a ratio of 1: 9 to 9: 1.

The light absorbers represented by the formulas (2) to (4) are monomolecular light absorbers, unlike polymer absorbers used in the related art. Whereas the anti-reflective coating layer is applied again after applying the embedding agent to the via hole or the trench formed without using the conventional light absorbing agent, the organic anti-reflective coating composition according to the embodiment of the present invention is a It is excellent in embedding characteristics by use, it is not necessary to reapply the anti-reflection film even when forming the pattern.

The organic antireflective coating composition according to one side of the present invention may include the curing agent. The curing agent may be a compound such as a mixture of dimethoxy and diethoxy methyl glycouril, tetramethoxymethyl glycouril, or hexamethoxymethyl melamine resin as the aminoplastic compound, and particularly preferably dimethoxy and Diethoxymethylglycouril mixture, tetramethoxymethylglycouril, or hexamethoxymethylmelamine resin. Polyfunctional epoxy compounds such as MY720, CY179MA, DENACOL and the like can be used.

There is a catalyst for promoting the curing reaction, and a thermal acid generator is used as a catalyst. As the thermal acid generator, a thermal acid generator capable of promoting a curing reaction can be widely used, and in particular, the compounds represented by the following Chemical Formulas 5 and 6, which are disclosed in JP-A-2003-0085808, can be used. In addition, any of toluene sulfonic acid, an amine salt or a pyridine salt compound of toluene sulfonic acid, an alkyl sulfonic acid, an amine salt of an alkyl sulfonic acid or a pyridine salt compound may be used.

In addition, as an organic solvent that can be used in the organic anti-reflective coating composition according to an embodiment of the present invention, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone, ethyl lactate, Propylene glycol n-propyl ether, dimethyl formamide (DMF), gamma-butyrolactone, ethoxy ethanol, methoxy ethanol, methyl3-methoxypropionate (MMP), ethyl3-ethoxypropionate (EEP One or more solvents selected from the group consisting of

According to another embodiment of the present invention, the organic anti-reflective film may include 0.1 to 40 wt% of a copolymer represented by the following formula (1), 0.1 to 40 wt% of a light absorber, 0.01 to 20 wt% of a thermal acid generator, and 0.01 to 40 wt% of a curing agent. It is formed by curing the composition for organic antireflective coating comprising%.

[Formula 1]

In formula (1), R is hydrogen or an alkyl group having 1 to 10 carbon atoms, an alcohol group having 1 to 10 carbon atoms, an alkyl ester group having 1 to 8 carbon atoms, a heteroalkyl group having 1 to 8 carbon atoms, or a cycloalkyl group having 3 to 14 carbon atoms And m and n are numbers representing repeating units, respectively, and satisfy a relational expression of m + n = 1, 0.05 <m <0.95 and 0.05 <n <0.95.

In the method for forming a pattern of a semiconductor device according to an embodiment of the present invention, the step of applying the organic anti-reflective coating composition on the etched layer and curing the applied composition through a baking process, cross linking Forming an organic anti-reflection film by forming a film;

The baking process may be performed for 1 to 5 minutes at a temperature of 180 to 230 ℃.

Hereinafter, an embodiment of the present invention will be described in detail.

Synthetic example  1) organic For anti-reflection film Polymerizer Synthesis of A

100 g of epoxy cresol novolac resin (Miwon Corporation), 31.86 g of ethyl vinyl ether, and 3.9 g of triethylamine were dissolved in 360 g of 1,4-dioxane, followed by polymerization at 70 ° C. for 12 hours. After the reaction was completed, ethyl acetate was added and washed several times with distilled water. After the organic layer was separated, the solvent was removed to some extent, and then dropped into hexane to form a precipitate. The resulting precipitate was filtered and washed several times with hexane and then dried in vacuo. (Yield = 72%)

Synthetic example  2) organic For anti-reflection film Polymerizer Synthesis of B

100 g of epoxy cresol novolac resin (Miwon Corporation), 40.03 g of bromoethane, and 40 g of sodium hydroxide were dissolved in 420 g of 1,4-dioxane and then polymerized at 70 ° C for 12 hours. After the reaction was completed, ethyl acetate was added and washed several times with distilled water. After the organic layer was separated, the solvent was removed to some extent, and then dropped into hexane to form a precipitate. The resulting precipitate was filtered and washed several times with hexane and then dried in vacuo. (Yield = 97%)

Synthetic example  3) organic For anti-reflection film Polymerizer Synthesis of C

100 g of epoxy cresol novolac resin (Miwon Corporation), 31.08 g of 2-bromoethanol, and 40 g of sodium hydroxide were dissolved in 420 g of 1,4-dioxane and then polymerized at 70 ° C. for 12 hours. After the reaction was completed, ethyl acetate was added and washed several times with distilled water. After the organic layer was separated, the solvent was removed to some extent, and then dropped into hexane to form a precipitate. The resulting precipitate was filtered and washed several times with hexane and then dried in vacuo. (Yield = 53%)

Synthetic example  4) organic For anti-reflection film Polymerizer Synthesis of D

50 g of an epoxy cresol novolac resin (Similar Co., Ltd.), 40.02 g of di-tert-butyl dicarbonate, and 20 g of sodium hydroxide were dissolved in 270 g of 1,4-dioxane and then polymerized at 70 ° C for 12 hours. After the reaction was completed, ethyl acetate was added and washed several times with distilled water. After the organic layer was separated, the solvent was removed to some extent, and then dropped into hexane to form a precipitate. The resulting precipitate was filtered and washed several times with hexane and then dried in vacuo. (Yield = 64%)

Synthetic example  5) Light absorber Synthesis of A

75 g of 4,4'-oxydiphthalic hydride, 100 g of anthracene methanol, and 7.3 g of diisopropylethylamine were dissolved in 540 g of 1,4-dioxane, and then reacted at 50 ° C for 16 hours. After the reaction is complete, the reaction solution is neutralized by dropping formic acid. The reactant was dropped into water, and the precipitate was filtered, washed several times with distilled water, and dried to obtain compound 172.8 (yield = 95%).

Synthetic example  6) Light absorber Synthesis of B

70 g of bicyclo 2,2,2 octene 2,3,5,6 tetracarboxylic acid dianhydride, 147 g of anthracene methanol, and 0.6 g of pyridine 46 g dimethylaminopyridine were dissolved in 540 g of 1,4-dioxane, and then at 50 ° C. The reaction was carried out for 24 hours. After the reaction is complete, the reaction solution is neutralized by dropping formic acid. The precipitate formed by dropping the reactant into water was filtered, washed several times with distilled water, and dried to obtain 172.8 g of a compound (yield = 80%).

Example  1: Preparation of Organic Antireflection Film Composition A

7 g of the organic anti-reflection film A prepared in Synthesis Example 1, 6 g of the light absorber A prepared in Synthesis Example 5, 2 g of tetramethoxymethylglycouril, and the structures of Formulas (5) and (6) 1 g of the thermal acid generator was dissolved in 966 g of propylene glycol monomethyl ether acetate, and then filtered through a 0.2 μm membrane filter to prepare an organic antireflective coating composition.

Example 2 Preparation of Organic Antireflection Film Composition B

7 g of the organic anti-reflection film B prepared in Synthesis Example 2, 8 g of the light absorber A prepared in Synthesis Example 5, 2.1 g of tetramethoxymethylglycouril, and the structures of Formulas (5) and (6) The organic antireflection film composition B was prepared by dissolving 1 g of the eggplant thermal acid generator in 981.9 g of ethyl lactate and then filtering it with a 0.2 μm diameter membrane filter.

Example 3 Preparation of Organic Antireflection Film Composition C

8 g of the organic antireflective film C prepared in Synthesis Example 3, 10 g of the light absorber A prepared in Synthesis Example 5, 2.7 g of tetramethoxymethylglycouril, and the structures of Formulas (5) and (6) The organic antireflective coating composition C is prepared by dissolving 0.54 g of a thermal acid generator in 978.76 g of propylene glycol monomethyl ether acetate and then filtering it with a 0.2 µm diameter membrane filter.

Example 4 Preparation of Organic Antireflection Film Composition D

8 g of the organic anti-reflection film D prepared in Synthesis Example 4, 6 g of the light absorber A prepared in Synthesis Example 5, 2.8 g of tetramethoxymethylglycouril, and the structures of Formulas (5) and (6) The organic antireflective coating composition D is prepared by dissolving 0.54 g of the thermal acid generator in 982.66 g of propylene glycol monomethyl ether acetate and then filtering with a 0.2 μm membrane filter.

Example 5 Preparation of Organic Antireflection Film Composition E

8 g of the organic antireflective film A prepared in Synthesis Example 1, 4 g of the light absorber B prepared in Synthesis Example 6, 1.7 g of tetramethoxymethylglycouril, and the structures of Formulas (5) and (6) The organic anti-reflective coating composition E is prepared by dissolving 0.4 g of the thermal acid generator in 985.9 g of propylene glycol monomethyl ether acetate and then filtering with a 0.2 μm membrane filter.

Example  6: organic antireflection film composition F  Produce

8 g of the organic anti-reflective coating polymer C prepared in Synthesis Example 3, 4 g of the light absorber B prepared in Synthesis Example 6, 1.7 g of tetramethoxymethylglycouril, and the structures of Formulas (5) and (6) The organic antireflective coating composition E is prepared by dissolving 0.4 g of the thermal acid generator in 985.9 g of propylene glycol monomethyl ether acetate and then filtering with a 0.2 μm membrane filter.

Stripping  Test

The organic antireflective coating composition prepared in Examples 1 to 6 was spin coated on a silicon wafer, and then baked for 1 minute on a plate heated to 230 ° C. to form an organic antireflective coating. After crosslinking, the thicknesses of the organic antireflection films were measured, and the wafers coated with the organic antireflection films were immersed in ethyl lactate for 1 minute. Thereafter, the ethyl lactate was completely removed, baked for 1 minute on a plate heated to 100 ° C., and the thickness of the organic antireflection film was measured again. As a result of the measurement, the thickness after the ethyl lactate treatment and the film thickness before the treatment could not be observed. That is, the prepared organic antireflective coating compositions were completely cured during the baking process, so that the intermixing with the photoresist did not occur during the lithography process.

Refractive index (n) and Extinction coefficient (k) measurement of values

The organic antireflective coating composition prepared in Examples 1 to 6 was spin coated on a silicon wafer, and then baked on a plate heated at 230 ° C. for 1 minute to form an organic antireflective coating. The antireflection film was measured for refractive index (n) and extinction coefficient (k) at 248 nm using a spectroscopic ellipsometer. As a result of the measurement, the refractive index n of the organic antireflection film composition A was 1.61, and the extinction coefficient k was 0.57. The refractive index n of the organic antireflective coating composition B was 1.65 and the extinction coefficient k was 0.52. The refractive index n of the organic antireflection film composition C was 1.58, and the extinction coefficient k was 0.49. The refractive index n of the organic antireflection film composition D was 1.61, the extinction coefficient k was 0.59, the refractive index n of the organic antireflection film composition E was 1.63, and the extinction coefficient k was 0.49. In addition, the refractive index n of the organic antireflection film composition F was 1.56, and the extinction coefficient k was 0.47.

Organic antireflection film and Photoresist  Pattern formation test

The organic antireflection film composition prepared in Example 1 was spin-coated on a silicon wafer on which silicon oxynitride was deposited, and then baked and crosslinked on a 230 ° C. hot plate for 1 minute to form an organic antireflection film. Thereafter, a photoresist prepared by Dongjin Semichem Co., Ltd. was coated on the antireflection film, and then baked at 100 ° C. for 90 seconds. After the baking was carried out, it was exposed using an NSR-203BC scanner equipment (0.68NA) and a 180 nm 1: 1 L / S pattern mask, and baked again at 110 ° C. for 75 seconds. The exposed wafer was developed using a TMAH 2.38% by weight developer to obtain a final photoresist pattern.

The photoresist pattern using the organic antireflection film composition A was a good vertical pattern, with an energy margin of about 22% and a depth of focus margin of about 0.6 μm. The photoresist pattern using the organic antireflection film composition B was a good vertical pattern, with an energy margin of about 23% and a depth of focus margin of about 0.5 μm. In addition, the photoresist pattern using the organic antireflection film composition C was a good vertical pattern, the energy margin was about 24%, the depth of focus margin was about 0.6㎛. The photoresist pattern using the organic antireflection film composition D was a good vertical pattern, with an energy margin of about 22% and a depth of focus margin of about 0.5 μm. The photoresist pattern using the organic antireflection film composition E was a good vertical pattern, with an energy margin of about 23% and a depth of focus margin of about 0.5 μm. In addition, the photoresist pattern using the organic antireflection film composition F was a good vertical pattern, the energy margin was about 19%, the depth of focus margin was about 0.5㎛.

Measurement of Etch Rate

The organic antireflective coating composition prepared in Examples 1 to 6 was spin-coated on a silicon wafer, and then baked and crosslinked on a 230 ° C. hot plate for 1 minute to form an organic antireflective coating. The silicon wafer on which the organic antireflection film was formed was etched for 10 seconds using CF ₄ gas on a dry etching equipment. The etching rate was defined as [(thickness of film before etching-thickness of film after etching) / time]. In terms of dry etching selectivity, the CF ₄ gas etching rates of the organic antireflective coating compositions A, B, and C were 2.25, 2.35, and 2.20, respectively. Dry etching selectivity indicates the dry etching rate of the organic antireflection film when the dry etching rate of the photoresist for KrF lithography is 1.00.

It was confirmed that the etching rate of the thin film obtained in the organic antireflective coating composition of the present invention of Examples 1 to 6 was very fast compared to the photoresist. In the process of transferring the photoresist pattern formed on the organic antireflection film to the substrate, if the etching rate of the organic antireflection film is fast, the photoresist pattern may be transferred to the substrate more accurately and easily.

Measurement of landfill characteristics

The gapfill property was measured using the organic antireflection film of this invention of Examples 1-6. Spin coating was applied to the via hole and the contact hole and baked for 1 minute on a plate heated to 230 ° C. to form a film for the landfill agent. The embedding membrane was confirmed using a scanning electron microscope. Referring to FIG. 1, the coating on the stepped pattern was measured using an electron microscope, and it was found that the flatness was excellent even when the embedding agent of the present invention was applied even on the stepped pattern. Referring to FIGS. 2 and 3, FIG. 2 is measured by using an electron microscope to apply the embedding agent of the present invention to a hole having a diameter of 360 nm and a depth of 900 nm, and FIG. 3 shows an aspect ratio having a diameter of 200 nm and a depth of 1500 nm. A deep hole having a large ratio was measured using an electron microscope, and all voids did not occur during the embedding process, and more than 50% of the landfill function was sufficient. It turned out that the flatness after filling is excellent. Also, in the dual damascene process, no voids occurred in the buried process, and it had a sufficient filling function of 50% or more, and the flatness after filling with the filling agent was excellent.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

Claims (5)

An organic antireflection film comprising a light absorber, a thermal acid generator, and a curing agent comprising at least one compound represented by the following formula (2) to (4) Composition.

(One)

(2) (3)

(4)
(In the formula (1), R is hydrogen or an alkyl group of 1 to 10 carbon atoms, an alcohol group of 1 to 10 carbon atoms, an alkyl ester group of 2 to 8 carbon atoms, a heteroalkyl group of 2 to 8 carbon atoms or of 4 to 14 carbon atoms) It is a cycloalkyl group, and said m and n are the numbers which represent a repeating unit, respectively, and are the value which satisfies the relationship of m + n = 1, 0.05 <m <0.95 and 0.05 <n <0.95. In 4), X is any one compound selected from the group consisting of a cyclic compound having 4 to 20 carbon atoms, aryl, diaryl ether, diaryl sulfide, diaryl sulfoxide and diaryl ketone, and R ₁ is 6 to C And an aryl group of 14, wherein Formula (2) and Formula (3) are isomers of each other.) The method of claim 1,
The composition is an organic antireflection film composition, characterized in that consisting of 0.1 to 40% by weight of the copolymer for the organic antireflection film, 0.1 to 40% by weight of the light absorber, 0.01 to 20% by weight of the thermal acid generator and 0.01 to 40% by weight of the curing agent. delete The method of claim 1,
The light absorbing agent is an organic antireflection film composition comprising a compound represented by the following formula (2) and formula (3) in a ratio of 1: 0.1 to 9.

(2) (3)
(In the formulas (2) and (3), X is any one selected from the group consisting of a cyclic compound having 4 to 20 carbon atoms, aryl, diaryl ether, diaryl sulfide, diaryl sulfoxide and diaryl ketone. Compound, R ₁ is an aryl group having 6 to 14 carbon atoms, and Formula (2) and Formula (3) are isomers of each other.) An organic antireflection film comprising a light absorber, a thermal acid generator, and a curing agent comprising at least one compound represented by the following formulas (2) to (4) An organic antireflection film formed by curing the composition.

(One)

(2) (3)

(4)
(In the formula (1), R is hydrogen or an alkyl group of 1 to 10 carbon atoms, an alcohol group of 1 to 10 carbon atoms, an alkyl ester group of 2 to 8 carbon atoms, a heteroalkyl group of 2 to 8 carbon atoms or of 4 to 14 carbon atoms) It is a cycloalkyl group, and said m and n are the numbers which respectively represent a repeating unit, and satisfy | fill the relationship of m + n = 1, 0.05 <m <0.95 and 0.05 <n <0.95. The said Formula (2)-( In 4), X is any one compound selected from the group consisting of a cyclic compound having 4 to 20 carbon atoms, aryl, diaryl ether, diaryl sulfide, diaryl sulfoxide and diaryl ketone, and R ₁ is 6 to C And an aryl group of 14, wherein Formula (2) and Formula (3) are isomers of each other.)

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