BLOCK COPOLYMER

Abstract

The present application provides a block copolymer and uses thereof. The block copolymer of the present application exhibits an excellent self-assembling property or phase separation property, can be provided with a variety of required functions without constraint and, especially, etching selectivity can be secured, making the block copolymer effectively applicable to such uses as pattern formation.

Claims

1. A block copolymer comprising a first block that is a structural unit represented by Structural Formula 1 below and a second block that is a structural unit represented by Structural Formula 3 below: ##STR00010## where in the Structural Formula 1, R represents a hydrogen atom or an alkyl group; X represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, a carbonyl group, an alkylene group, an alkenylene group, an alkynylene group, —C(═O)—X.sub.1— or —X.sub.1—C(═O)—, wherein the X.sub.1 represents an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group; Y represents a monovalent substituent that includes a ring structure to which a linear chain including 8 or more chain-forming atoms is connected; and where in the Structural Formula 3, X.sub.2 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group, an alkynylene group, —C(═O)—X.sub.2— or —X.sub.2—C(═O)—, wherein the X.sub.2 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group; and each of R.sub.1 to R.sub.5 independently represents a hydrogen atom, an alkyl group, a haloalkyl group, a halogen atom or a crosslinking functional group, wherein one or more crosslinking functional groups are included in positions marked as R.sub.1 to R.sub.5.

2. The block copolymer of claim 1, wherein the X represents a single bond, an oxygen atom, a carbonyl group, —C(═O)—O—, or —O—C(═O)—.

3. The block copolymer of claim 1, wherein the linear chain includes 8 to 20 chain-forming atoms.

4. The block copolymer of claim 1, wherein the chain-forming atom is carbon, oxygen, nitrogen, or sulfur.

5. The block copolymer of claim 1, wherein the chain-forming atom is carbon or oxygen.

6. The block copolymer of claim 1, wherein the ring structure of the Y is an aromatic ring structure or an alicyclic ring structure.

7. The block copolymer of claim 1, wherein the Y of the Structural Formula 1 is represented by Structural Formula 2 below:
—P-Q-Z  [Structural Formula 2] where in the Structural Formula 2, P represents an arylene group; Q represents a single bond, an oxygen atom or —NR.sub.3—, wherein the R.sub.3 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group or an aryl group; and Z represents a linear chain with 8 or more chain-forming atoms.

8. The block copolymer of claim 1, wherein the crosslinking functional group is an azide-containing functional group, a sulfur-containing functional group, or a functional group containing one or more unsaturated double bonds.

9. The block copolymer of claim 1, wherein one or more halogen atoms are included in the positions marked as R.sub.1 to R.sub.5 of the Structural Formula 3.

10. The block copolymer of claim 1 comprising: the second block that includes the structural unit of the Structural Formula 3 in a proportion ranging from 0.1 mol % to 5 mol %.

11. The block copolymer of claim 1, wherein the second block further includes a structural unit represented by Structural Formula 4 below: ##STR00011## where in the Structural Formula 4, X.sub.2 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group, an alkynylene group, —C(═O)—X.sub.1— or —X.sub.1—C(═O)—, wherein the X.sub.1 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group; and W represents an aryl group that includes at least one halogen atom.

12. The block copolymer of claim 1, wherein the second block further includes a structural unit represented by Structural Formula 5 below: ##STR00012## where in the Structural Formula 5, X.sub.3 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group, an alkynylene group, —C(═O)—X.sub.1— or —X.sub.1—C(═O)—, wherein the X.sub.1 represents a single bond, an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group; and each of R.sub.a to R.sub.e independently represents a hydrogen atom, an alkyl group, a haloalkyl group or a halogen atom, wherein one or more halogen atoms are included in positions marked as R.sub.a to R.sub.e.

13. The block copolymer of claim 12, wherein 3 or more halogen atoms are included in the positions marked as R.sub.a to R.sub.e.

14. The block copolymer of claim 12, wherein 5 or more halogen atoms are included in the positions marked as R.sub.a to R.sub.e.

15. The block copolymer of claim 12, wherein the halogen atom is a fluorine atom.

16. A polymer film comprising the block copolymer of claim 1, wherein the block copolymer is self-assembled.

17. The polymer film of claim 16, wherein the second block of the block copolymer includes a crosslinked structure.

18. A method of forming a polymer film, the method comprising: forming a polymer film that includes the block copolymer of claim 1 on a substrate, wherein the block copolymer is self-assembled.

19. The method of claim 18, further comprising: crosslinking of the second block of the block copolymer, wherein the block copolymer is self-assembled.

20. A method of forming a pattern, the method comprising: selectively removing any one block of the block copolymer of claim 1 from a laminate that is made up of a substrate and a polymer film, which is formed on the substrate and includes the block copolymer, wherein the block copolymer is self-assembled.

21. The polymer film of claim 20, wherein the second block of the block copolymer includes a crosslinked structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0123] FIGS. 1 and 2 are images that illustrate the SEM results of a polymer film.

EFFECT

[0124] The present application can provide a block copolymer and uses thereof. The block copolymer of the present application exhibits an excellent self-assembling property or phase separation property, can be provided with a variety of required functions without constraint and, especially, etching selectivity can be secured, making the block copolymer effectively applicable to such uses as pattern formation.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0125] The present application is described in more detail hereinafter through examples according to the present application, but the scope of the present application is not limited to the examples which are proposed hereinafter.

[0126] 1. NMR Measurement

[0127] NMR analysis was carried out at room temperature by using a NMR spectrometer that includes a Varian Unity Inova (500 MHz) spectrometer with a 5-mm triple resonance probe. The analysis subject material was diluted with a solvent (CDCl.sub.3) for an NMR measurement to a concentration of about 10 mg/ml for use, and the chemical shift was expressed in ppm.

[0128] <Applied Abbreviations>

[0129] br=broad signal, s=singlet, d=doublet, dd=doublet of doublets, t=triplet, dt=doublet of triplets, q=quartet, p=quintet, m=multiplet.

[0130] 2. Gel Permeation Chromatography (GPC)

[0131] The number average molecular weight (Mn) and molecular weight distribution were measured by GPC. The analysis subject material such as a macroinitiator or the block copolymer of the examples was put in a 5-mL vial and diluted with tetrahydrofuran (THF) to a concentration of about 1 mg/mL. Then, a standard specimen for calibration and the specimen to be analyzed were filtered with a syringe filter (pore size: 0.45 μm) and subsequently analyzed. ChemStation (Agilent Technologies Inc.) was used as the analytical program, each of the weight average molecular weight (Mw) and Mn was obtained by comparing the elution time of the specimen with the calibration curve, and then a molecular weight distribution (polydispersity index, PDI) was calculated as a ratio (Mw/Mn). The measuring condition of GPC is as follows:

[0132] <GPC Measuring Conditions>

[0133] Device: 1200 Series of Agilent Technologies Inc.

[0134] Column: Two PLgel MIXED-B of Polymer Laboratories

[0135] Solvent: THF

[0136] Column temperature: 35° C.

[0137] Sample concentration: 1 mg/mL, 200 L is injected

[0138] Standard specimen: polystyrene (Mp: 3900000, 723000, 316500, 52200, 31400, 7200, 3940, 485)

Preparation Example 1

[0139] The compound (DPM-C12) represented by the following Structural Formula A was synthesized by the following method: hydroquinone (10.0 g, 94.2 mmol) and 1-bromododecane (23.5 g, 94.2 mmol) were introduced into a 250-mL flask, dissolved in 100 mL of acetonitrile; then, an excessive amount of potassium carbonate was added to the above solution and allowed to react at about 75° C. for about 48 hours under a nitrogen atmosphere; upon completion of the reaction, the reaction products were removed of the remaining potassium carbonate and of acetonitrile that was used for the reaction; then the substances were worked up through an addition of a mixed solvent of dichloromethane (DCM) and water, and the separated organic layer was dehydrated with MgSO.sub.4; subsequently, the substances were purified by column chromatography (CC) with DCM to obtain a white solid intermediate with a yield of about 37%.

[0140] <NMR Analysis Results of Intermediate>

[0141] .sup.1H-NMR (CDCl.sub.3): δ6.77 (dd, 4H); 64.45 (s, 1H); δ3.89 (t, 2H); δ1.75 (p, 2H); δ1.43 (p, 2H); δ1.33-1.26 (m, 16H); δ0.88 (t, 3H).

[0142] The synthesized intermediate (9.8 g, 35.2 mmol), methacrylic acid (6.0 g, 69.7 mmol), dicyclohexylcarbodiimide (DCC) (10.8 g, 52.3 mmol) and p-dimethylaminopyridine (DMAP) (1.7 g, 13.9 mmol) were introduced into a flask, 120 mL of methylene chloride was added, and then allowed to react at room temperature for 24 hours under a nitrogen atmosphere; upon completion of the reaction, the reaction products were filtered to be removed of a urea salt that was produced during the reaction and also of the remaining methylene chloride; then, the substances were removed of impurities by column chromatography (CC) that uses hexane and dichloromethane (DCM) as the mobile phase, the obtained products were recrystallized in a mixed solvent of methanol and water (mixed at a weight ratio of 1:1) to obtain a white solid target material (DPM-C12) (7.7 g, 22.2 mmol) with a yield of 63%.

[0143] <NMR Analysis Results of DPM-C12>

[0144] .sup.1H-NMR (CDCl.sub.3): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.32 (dt, 1H); δ5.73 (dt, 1H); δ3.94 (t, 2H); δ2.05 (dd, 3H); δ1.76 (p, 2H); δ1.43 (p, 2H); 1.34-1.27 (m, 16H); δ0.88 (t, 3H).

##STR00008##

[0145] In Structural Formula A, R represents a linear-chain alkyl group with 12 carbons.

Preparation Example 2

[0146] The compound represented by the following Structural Formula B was synthesized by the following method: first, 3-hydroxy-1,2,4,5-tetrafluorostyrene was synthesized and obtained by adding pentafluorostyrene (25 g, 129 mmol) to 400 mL of a mixed solution of tert-butanol and potassium hydroxide (37.5 g, 161 mmol), all of which were allowed to have a reflux reaction for 2 hours; cooling the reactants to room temperature and then adding 1200 mL of water; extracting the adducts with diethyl ether (300 mL) for 3 times through a process of volatilizing any remaining butanol that was used in the previous reaction; acidifying the aqueous solution layer with a 10-wt % hydrochloric acid solution to a pH of about 3 to precipitate the target materials; collecting the organic layer through extraction with diethyl ether (300 mL) again for 3 times and then dehydrating it with MgSO.sub.4 and removing the solvent; and purifying the obtained crude product by column chromatography by using hexane and dichloromethane (DCM) as the mobile phase to acquire colorless liquid 3-hydroxy-1,2,4,5-tetrafluorostyrene (11.4 g). The results of NMR analysis on the above substance are as follows.

[0147] <NMR Analysis Results>

[0148] .sup.1H-NMR (DMSO-d): δ11.7 (s, 1H); δ6.60 (dd, 1H); δ5.89 (d, 1H); δ5.62 (d, 1H)

[0149] The obtained 3-hydroxy-1,2,4,5-tetrafluorostyrene (3.0 g, 16 mmol), chloroacetyl chloride (3.5 g, 31 mmol) and triethylamine (2.5 g, 25 mmol) were dissolved in ethyl ether (250 mL); after a reaction for 1 hour, the reaction products were removed of solvent and then put through column chromatography with a methyl chloride (MC)/hexane solution to obtain a transparent liquid target compound (represented by the following Structural Formula B) (2 g, 8 mmol, 51%).

[0150] The results of NMR analysis on the above compound is as follows.

[0151] <NMR Analysis Results>

[0152] .sup.1H-NMR (CDCl.sub.3-d): δ6.66 (dd, 1H); δ6.12 (d, 1H); δ5.75 (d, 1H), δ4.41 (s, 2H)

##STR00009##

Example 1

[0153] In order to polymerize a block copolymer by using synthesized monomers, azobisisobutyronitrile (AIBN) was used as the polymerization initiator, which was dissolved with a reversible addition-fragmentation chain transfer (RAFT) reagent (2-cyano-2-propyl dodecyl trithiocarbonate) and the compound (DPM monomer) of Preparation Example 1 represented by Structural Formula A in anisole in a weight ratio of 30:2:0.2 (DPM:RAFTreagent:AIBN) to obtain a solution whose solid concentration is about 30 wt %. The above solution was allowed to react at 70° C. for 4 hours under a nitrogen atmosphere to synthesize a macroinitiator (number average molecular weight: 6800, molecular weight distribution: 1.16), which was dissolved with AIBN, pentafluorostyrene (PFS) and the compound of the above Structural Formula B (Preparation Example 2) in anisole at a weight ratio of 1:490:10:0.5 (macroinitiator:PFS:compound represented by Structural Formula B:AIBN) to prepare a solution whose solid concentration is about 70 wt %. The prepared solution was allowed to react at 70° C. for 2.5 hours under a nitrogen atmosphere to prepare a block copolymer (number average molecular weight: 13500, molecular weight distribution: 1.20). The prepared block copolymer was reacted with NaN.sub.3 at room temperature for 24 hours to substitute the contained chloride (Cl), which was derived from the structural unit of the compound (represented by Structural Formula B), by an azide functional group, and thereby a block copolymer was obtained.

Test Example 1

[0154] A self-assembled polymer film was formed by using the block copolymer that was synthesized in Example 1, and the results were observed. The prepared block copolymer was dissolved in a solvent to a concentration of 0.5 wt % and then spin-coated on a silicon wafer for about 60 seconds at a speed of about 3000 rpm to form a polymer thin film. The film was thermal-annealed at 160° C. for 1 hour to induce microphase separation, and the microstructure of the corresponding block copolymer can be seen in FIG. 1 below. FIG. 2 shows the result by which selective etching after crosslinking of the above block copolymer at about 200° C. or more is identified, and it can be seen from FIG. 2 that selective etching of the above block copolymer is possible.