Laminate

Abstract

The present application relates to a block copolymer and a use thereof. The present application can provide a laminate which is capable of forming a highly aligned block copolymer on a substrate and thus can be effectively applied to production of various patterned substrates, and a method for producing a patterned substrate using the same.

Claims

1. A laminate comprising a block copolymer film which comprises a block copolymer comprising a polymer segment A satisfying one or more of Conditions 1 to 3 below and a polymer segment B different from the polymer segment A and having an absolute value of a difference in surface energy with the polymer segment A of 10 mN/m or less; and a random copolymer film which is formed in contact with the block copolymer film and comprises a random copolymer comprising a monomer unit of Formula 1 below and a monomer unit of Formula 3 below, wherein in the random copolymer, the monomer unit of Formula 3 has a volume fraction in a range of 0.45 to 0.65 and the sum of volume fraction of the monomer unit of Formula 1 and the volume fraction of the monomer unit of Formula 3 is 1: Condition 1: it exhibits a melting transition peak or an isotropic transition peak in a range of −80° C. to 200° C. in a differential scanning calorimetry (DSC) analysis, Condition 2: it exhibits a peak having a half-value width in a range of 0.2 to 0.9 nm.sup.−1 within a scattering vector (q) range of 0.5 nm.sup.−1 to 10 nm.sup.−1 in an X-ray diffraction (XRD) analysis, Condition 3: it comprises a side chain, which satisfies Equation 1 below:
3 nm.sup.−1 to 5 nm.sup.−1=nq/(2×π)   [Equation 1] wherein, n is a number of chain-forming atoms in the side chain and q is the smallest scattering vector in which a peak is observed in the XRD analysis for the block copolymer or the scattering vector in which a peak of the largest peak area is observed, ##STR00006## wherein, R is hydrogen or an alkyl group having 1 to 4 carbon atoms, X is 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)—, where X.sub.1 is an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group, and Y is a monovalent substituent comprising a ring structure to which a side chain having 8 or more chain-forming atoms is linked, ##STR00007## wherein, X.sub.2 is 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)—, where X.sub.1 is 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 is an aryl group containing at least one halogen atom.

2. The laminate according to claim 1, further comprising a substrate in which a trench having a bottom portion and two sidewalls is formed by mesa structures disposed at a distance from each other on the a surface, wherein the block copolymer film is formed in contact with the random copolymer film in the trench.

3. The laminate according to claim 1, wherein the block copolymer film forms a lamellar structure.

4. The laminate according to claim 3, wherein the block copolymer film has a thickness in a range of 1 L to 10 L, where L is a pitch of the lamellar structure.

5. The laminate according to claim 1, wherein the polymer segment A comprises a side chain having 8 or more chain-forming atoms.

6. The laminate according to claim 5, wherein the polymer segment A comprises a ring structure and the side chain is substituted on the ring structure directly or via a linker.

7. The laminate according to claim 5, wherein the polymer segment B comprises three or more halogen atoms.

8. The laminate according to claim 7, wherein the polymer segment B comprises a ring structure and the halogen atoms are substituted on the ring structure.

9. The laminate according to claim 2, wherein the ratio of the distance between the mesa structures and the height of each of the mesa structures is in a range of 0.1 to 10, and the ratio of the distance between the mesa structures and the width of each of the mesa structures is in a range of 0.5 to 10.

10. The laminate according to claim 6, wherein the ring structure in the polymer segment A is an aromatic or an alicyclic ring, and no halogen atom is present on the ring structure.

11. The laminate according to claim 8, wherein the ring structure in the polymer segment B comprises is an aromatic or an alicyclic ring.

12. The laminate according to claim 5, wherein the chain-forming atoms are each independently a carbon, an oxygen, a nitrogen or a sulfur atom.

13. The laminate according to claim 6, wherein the linker is an oxygen atom, a sulfur atom, —NR.sub.1—, —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 R.sub.1 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group or an aryl group, and X.sub.1 is a single bond, an oxygen atom, a sulfur atom, —NR.sub.2—, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group, where R.sub.2 is hydrogen, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group or an aryl group.

14. The laminate according to claim 3, wherein the random copolymer film has a thickness in a range of 0.5 nm to 10 nm.

15. A method for producing a patterned substrate comprising forming a random copolymer film which comprises a random copolymer comprising a monomer unit of Formula 1 below and a monomer unit of Formula 3 below on a substrate, wherein in the random copolymer, the monomerunit of Formula 3 has a volume fraction in a range of 0.45 to 0.65 and the sum of volume fraction of the monomer unit of Formula 1 and the volume fraction of the monomer unit of Formula 3 is 1, and forming a self-assembled block copolymer film in contact with the random copolymer film, wherein the block copolymer film comprises a block copolymer which comprises a polymer segment A satisfying one or more of Conditions 1 to 3 below and a polymer segment B different from the polymer segment A and having an absolute value of a difference in surface energy with the polymer segment A of 10 mN/m or less: Condition 1: it exhibits a melting transition peak or an isotropic transition peak in a range of −80° C. to 200° C. in a differential scanning calorimetry (DSC) analysis, Condition 2: it exhibits a peak having a half-value width in a range of 0.2 to 0.9 nm.sup.−1 within a scattering vector (q) range of 0.5 nm.sup.−1 to 10 nm.sup.−1 in an X-ray diffraction (XRD) analysis, Condition 3: it comprises a side chain, which satisfies Equation 1 below:
3 nm.sup.−1 to 5 nm.sup.−1=nq/(2×π)   [Equation 1] wherein, n is a number of the-chain-forming atoms in the side chain and q is the smallest scattering vector in which a peak is observed in the XRD analysis for the block copolymer or the scattering vector in which a peak of the largest peak area is observed, ##STR00008## wherein, R is hydrogen or an alkyl group having 1 to 4 carbon atoms, X is 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)—, where X.sub.1 is an oxygen atom, a sulfur atom, —S(═O).sub.2—, an alkylene group, an alkenylene group or an alkynylene group, and Y is a monovalent substituent comprising a ring structure to which a side chain having 8 or more chain-forming atoms is linked, ##STR00009## wherein, X.sub.2 is 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)—, where X.sub.1 is 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 is an aryl group containing at least one halogen atom.

16. The method for producing a patterned substrate according to claim 15, wherein a trench having a bottom portion and two sidewalls is formed by mesa structures disposed at a distance from each other on a surface of the substrate, and the random copolymer film is formed on all the two sidewalls and the bottom portion of the trench.

17. The method for producing a patterned substrate according to claim 15, further performing steps of selectively removing any one polymer segment of the block copolymer film on which a self-assembled structure is formed; and etching the substrate using the block copolymer, from which the polymer segment is removed, as a mask.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows an exemplary form of a substrate on which a trench is formed.

(2) FIG. 2 schematically shows a form in which a self-assembled polymer is formed into a trench of a substrate.

(3) FIG. 3 is a view showing an analysis result of GIWAXS of a homopolymer prepared using monomer of Preparation Example 1. The top figure depicts the intensity of incidence with respect to the azimuthal angle, and the lower figure depicts the Gauss fitting results of the intensity with respect to the azimuthal angle.

(4) FIG. 4 is a SEM image of the self-assembled polymer pattern prepared in Example 1. The top figure depicts a top view image of the self-assembled polymer pattern prepared in Example 1, and the lower figure depicts a side view image of the self-assembled polymer pattern prepared in Example 1.

(5) FIG. 5 is a SEM image of the self-assembled polymer pattern prepared in Example 2. The top figure depicts a top view image of the self-assembled polymer pattern prepared in Example 1, and the lower figure depicts a side view image of the self-assembled polymer pattern prepared in Example 2.

MODE FOR INVENTION

(6) Hereinafter, the present application will be described in detail by way of examples according to the present application and comparative examples, but the scope of the present application is not limited by the following examples.

(7) 1. NMR Measurement

(8) NMR analyses were performed at room temperature using an NMR spectrometer including a Varian Unity Inova (500 MHz) spectrometer with a triple resonance 5 mm probe. The analytes were diluted in a solvent for NMR measurement (CDCl.sub.3) to a concentration of about 10 mg/ml, and chemical shifts were expressed in ppm.

(9) <Application Abbreviation>

(10) br=broad signal, s=singlet, d=doublet, dd=double doublet, t=triplet, dt=double triplet, q=quartet, p=quintet, m=multiplet.

(11) 2. GPC (Gel Permeation Chromatograph)

(12) The number average molecular weight (Mn) and the molecular weight distribution were measured using GPC (gel permeation chromatography). Into a 5 mL vial, an analyte such as block copolymers of Examples or Comparative Examples or a giant initiator is put and diluted in THF (tetrahydrofuran) to be a concentration of about 1 mg/mL or so. Then, a standard sample for calibration and a sample to be analyzed were filtered through a syringe filter (pore size: 0.45 μm) and then measured. As the analytical program, ChemStation from Agilent Technologies was used, and the elution time of the sample was compared with the calibration curve to obtain the weight average molecular weight (Mw) and the number average molecular weight (Mn), respectively, and the molecular weight distribution (PDI) was calculated by the ratio (Mw/Mn) thereof. The measurement conditions of GPC are as follows.

(13) <GPC Measurement Condition>

(14) Instrument: 1200 series from Agilent Technologies

(15) Column: using two PLgel mixed B from Polymer Laboratories

(16) Solvent: THF

(17) Column temperature: 35

(18) Sample concentration: 1 mg/mL, 200 L injection

(19) Standard sample: polystyrene (Mp: 3900000, 723000, 316500, 52200, 31400, 7200, 3940, 485)

(20) 3. GISAXS (Grazing Incidence Small Angle X-Ray Scattering)

(21) The grazing incidence small angle X-ray scattering (GISAXS) analysis was performed using a Pohang accelerator 3C beamline. The block copolymer to be analyzed was diluted in fluorobenzene to a solid concentration of about 0.7 wt % to prepare a coating liquid, and the coating liquid was spin-coated on a base material to a thickness of about 5 nm. The coating area was adjusted to 2.25 cm.sup.2 or so (width: 1.5 cm, height: 1.5 cm). The coated polymer film was dried at room temperature for about 1 hour and thermally annealed again at about 160° C. for about 1 hour to induce a phase separation structure. Subsequently, a film, in which the phase separation structure was formed, was formed. After an X-ray was incident on the film at an incident angle in a range of about 0.12 degrees to 0.23 degrees corresponding to the angle between the critical angle of the film and the critical angle of the base material, an X-ray diffraction pattern, which was scattered from the film to a detector (2D marCCD) and exited, was obtained. At this time, the distance from the film to the detector was selected as such a range that the self-assembly pattern formed on the film was well observed within a range of about 2 m to 3 m. As the base material, a base material having a hydrophilic surface (a silicon substrate treated with a piranha solution and having a room temperature wetting angle of about 5 degrees to pure water) or a base material having a hydrophobic surface (a silicon substrate treated with HMDS (hexamethyldisilazane) and having a room temperature wetting angle of about 60 degrees to pure water) was used.

(22) 4. XRD Analysis Method

(23) The XRD analysis was performed by transmitting X rays to a sample at a Pohang accelerator 4C beamline to measure the scattering intensity according to the scattering vector (q). As the sample, a polymer in a powder state dried by purifying a synthesized polymer without special pretreatment and then maintaining it in a vacuum oven for one day or so, was placed in a cell for XRD measurement and used. Upon the XRD pattern analysis, an X-ray with a vertical size of 0.023 mm and a horizontal size of 0.3 mm was used and a 2D marCCD was used as a detector. A 2D diffraction pattern scattered and exited was obtained as an image. The obtained diffraction pattern was analyzed by a numerical analytical method to which a least-square method was applied to obtain information such as a scattering vector and a half-value width. Upon the analysis, an origin program was applied, and the profile of the XRD patterns was subjected to Gaussian fitting in a state where a portion showing the smallest intensity in the XRD diffraction patterns was taken as a baseline and the intensity in the above was set to zero, and then the scattering vector and the half-value width were obtained from the fitted results. The R square was set to be at least 0.96 or more upon Gaussian fitting.

(24) 5. Measurement of Surface Energy

(25) The surface energy was measured using a drop shape analyzer (DSA100 product from KRUSS). A coating liquid was prepared by diluting the substance (polymer), which is measured, in fluorobenzene to a solid concentration of about 2 wt %, and the prepared coating liquid was spin-coated on a silicon wafer to a thickness of about 50 nm and a coating area of 4 cm.sup.2 (width: 2 cm, height: 2 cm). The coating layer was dried at room temperature for about 1 hour and then subjected to thermal annealing at about 160° C. for about 1 hour. The process of dropping the deionized water whose surface tension was known on the film subjected to thermal annealing and obtaining the contact angle thereof was repeated five times to obtain an average value of the obtained five contact angle values. In the same manner, the process of dropping the diiodomethane whose surface tension was known thereon and obtaining the contact angle thereof was repeated five times to obtain an average value of the obtained five contact angle values. The surface energy was obtained by substituting the value (Strom value) regarding the solvent surface tension by the Owens-Wendt-Rabel-Kaelble method using the obtained average values of the contact angles for the deionized water and diiodomethane. The numerical value of the surface energy for each polymer segment of the block copolymer was obtained for a homopolymer made of only the monomer forming the polymer segment by the above-described method.

(26) 6. GIWAXS (Grazing Incidence Wide Angle X-Ray Scattering)

(27) The grazing incidence wide angle X-ray scattering (GIWAXS) analysis was performed using a Pohang accelerator 3C beamline. The homopolymer to be analyzed was diluted in toluene to a solid concentration of about 1 wt % to prepare a coating liquid, and the coating liquid was spin-coated on a base material to a thickness of about 30 nm. The coating area was adjusted to about 2.25 cm.sup.2 (width: 1.5 cm, height: 1.5 cm). The coated polymer film was dried at room temperature for about 1 hour and then subjected to thermal annealing at a temperature of about 160° C. for about 1 hour to form a film. After an X-ray was incident on the film at an incident angle in a range of about 0.12 degrees to 0.23 degrees corresponding to the angle between the critical angle of the film and the critical angle of the base material, an X-ray diffraction pattern, which was scattered from the film to a detector (2D marCCD) and exited, was obtained. At this time, the distance from the film to the detector was selected as such a range that the crystal or liquid crystal structure formed on the film was well observed within a range of about 0.1 m to 0.5 m. As the base material, a silicon substrate treated with a piranha solution and having a room temperature wetting angle of about 5 degrees to pure water was used. In the GIWAXS spectrum, the scattering intensity in the azimuthal angle range of −90 degrees to 90 degrees of the diffraction pattern in the range of 12 nm.sup.−1 to 16 nm.sup.−1 (azimuthal angle when the upward direction of the diffraction pattern (out-of-plane diffraction pattern) is set as 0 degrees) was plotted, and the half-value width was obtained from the graph through Gauss fitting. Furthermore, when half of the peak was observed upon Gauss fitting, twice the value of the obtained half-value width (FWHM) was defined as the half-value width of the peak.

(28) 7. DSC Analysis

(29) The DSC analysis was performed using PerkinElmer DSC800 equipment. Using the equipment, it was performed by a method in which the sample to be analyzed was heated at a speed of 10° C. per minute from 25° C. to 200° C., cooled again at a speed of −10° C. per minute from 200° C. to −80° C., and raised at a speed of 10° C. per minute from −80° C. to 200° C. under a nitrogen atmosphere to obtain an endothermic curve. The obtained endothermic curve was analyzed to obtain a temperature (melting transition temperature, Tm) indicating a melting transition peak or a temperature (isotropic transition temperature, Ti) indicating an isotropic transition peak, and the area of the peak was obtained. Here, the temperature was defined as the temperature corresponding to the apex of each peak. The area per unit mass of each peak is defined as the value obtained by dividing the area of each peak by the mass of the sample, and this calculation can be calculated using the program provided by the DSC equipment.

(30) Preparation Example 1. Synthesis of Monomer (A)

(31) A monomer (DPM-C12) of Formula A below was synthesized in the following manner. Hydroquinone (10.0 g, 94.2 mmol) and 1-bromododecane (23.5 g, 94.2 mmol) were placed in a 250 mL flask, dissolved in 100 mL of acetonitrile, and then an excess amount of potassium carbonate was added thereto and reacted at 75° C. for about 48 hours under a nitrogen condition. After the reaction, the remaining potassium carbonate was filtered off and the acetonitrile used in the reaction was also removed. A mixed solvent of DCM (dichloromethane) and water was added thereto to work up the mixture, and the separated organic layers were collected and passed through MgSO.sub.4 to be dehydrated. Subsequently, the target product (4-dodecyloxyphenol) (9.8 g, 35.2 mmol) in a white solid phase was obtained in a yield of about 37% using dichloromethane in column chromatography.

(32) <NMR Analysis Result>

(33) .sup.1H-NMR (CDCl.sub.3): d6.77 (dd, 4H); δd4.45 (s, 1H); d3.89 (t, 2H); d1.75 (p, 2H); d1.43 (p, 2H); d1.33-1.26 (m, 16H); d0.88 (t, 3H).

(34) The synthesized 4-docecyloxyphenol (9.8 g, 35.2 mmol), methacrylic acid (6.0 g, 69.7 mmol), DCC (dicyclohexylcarbodiimide) (10.8 g, 52.3 mmol) and DMAP (p-dimethylaminopyridine) (1.7 g, 13.9 mmol) were placed in the flask and 120 mL of methylene chloride was added thereto, and then reacted at room temperature for 24 hours under nitrogen. After completion of the reaction, the salt (urea salt) generated during the reaction was filtered off and the remaining methylene chloride was also removed. Impurities were removed using hexane and DCM (dichloromethane) as the mobile phase in column chromatography and the product obtained again was recrystallized in a mixed solvent of methanol and water (1:1 mix) to obtain the target product (7.7 g, 22.2 mmol) in a white solid phase in a yield of 63%.

(35) <NMR Analysis Result>

(36) .sup.1H-NMR (CDCl.sub.3): d7.02 (dd, 2H); δd6.89 (dd, 2H); d6.32 (dt, 1H); d5.73 (dt, 1H); d3.94 (t, 2H); 6d 2.05(dd, 3H); d1.76 (p, 2H); δd1.43 (p, 2H); 1.34-1.27 (m, 16H); d0.88 (t, 3H).

(37) ##STR00005##

(38) In Formula A, R is a linear alkyl group having 12 carbon atoms.

(39) GIWAXS, XRD and DSC Analyses

(40) A homopolymer was prepared using the monomer (A) of Preparation Example 1, and GIWAXS and DSC were analyzed for the prepared homopolymer. Here, the homopolymer was prepared by a method of synthesizing a macromonomer using the monomer (A) in the following examples. FIG. 3 shows the results of GIWAXS analysis of the homopolymer. In FIG. 3, R square (R square) was about 0.264 upon Gauss fitting. As a result of the DSC analysis for the homopolymer, the corresponding polymer showed a melting temperature of about −3° C. and an isotropic transition temperature of about 15° C. Also, the ratio (M/I) of the area (M) of the melting transition peak to the area (I) of the isotropic transition peak in the DSC analysis of the homopolymer was about 3.67, the half-value width of the peak in an azimuthal angle of −90 degrees to −70 degrees of the diffraction pattern of the scattering vector in a range of 12 nm.sup.−1 to 16 nm.sup.−1 in GIWAXS was about 48 degrees, and the half-value width of the peak in an azimuthal angle of 70 degrees to 90 degrees of the diffraction pattern of the scattering vector in a range of 12 nm.sup.−1 to 16 nm.sup.−1 in GIWAXS was about 58 degrees. Furthermore, in the X-ray diffraction analysis (XRD), a peak having a half-value width of about 0.57 nm.sup.−1 or so was observed at a scattering vector value of 1.96 nm.sup.−1.

(41) Preparation Example 2. Synthesis of Block Copolymer (A)

(42) 2.0 g of the monomer (A) of Preparation Example 1, 64 mg of cyanoisoproyl dithiobenzoate as an RAFT (reversible addition-fragmentation chain transfer) reagent, 23 mg of AIBN (azobisisobutyronitrile) as a radical initiator and 5.34 mL of benzene were placed in a 10 mL Schlenk flask and stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then an RAFT (reversible addition-fragmentation chain transfer) polymerization reaction was performed at 70° C. for 4 hours. After the polymerization, the reaction solution was precipitated in 250 mL of methanol as an extraction solvent, and then filtered under reduced pressure and dried to prepare a pink macro initiator. The yield of the macro initiator was about 82.6 wt % and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 9,000 g/mol and 1.16, respectively. 0.3 g of the macro initiator, 2.7174 g of a pentafluorostyrene monomer and 1.306 mL of benzene were placed in a 10 mL Schlenk flask and stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then an RAFT (reversible addition-fragmentation chain transfer) polymerization reaction was performed at 115° C. for 4 hours. After the polymerization, the reaction solution was precipitated in 250 mL of methanol as an extraction solvent, and then filtered under reduced pressure and dried to prepare a pale pink polymer segment copolymer. The yield of the block copolymer was about 18 wt %, and the number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) were 14,400 g/mol, respectively. The block copolymer comprises a polymer segment A, which is derived from the monomer (A) of Preparation Example 1 and has 12 chain-forming atoms (the number of carbon atoms of R in Formula A), and a polymer segment B derived from the pentafluorostyrene monomer. Here, the volume fraction of the polymer segment A was about 0.41, and the volume fraction of the polymer segment B was about 0.59. The surface energy and density of the polymer segment A of the block copolymer were 30.83 mN/m and 1 g/cm.sup.3, respectively, and the surface energy and density of the polymer segment B were 24.4 mN/m and 1.57 g/cm.sup.3, respectively. Also, the result calculated by substituting the number of chain-forming atoms (12) in the polymer segment A of the block copolymer and the scattering vector value (q) in which the peak having the largest peak area was identified in the scattering vector range of 0.5 nm.sup.−1 to 10 nm.sup.−1 upon the X-ray diffraction analysis into the equation nq/(2×π), respectively, was about 3.75.

(43) Preparation Example 3. Synthesis of Block Copolymer (B)

(44) A block copolymer was synthesized in the same manner as in Preparation Example 2, except that the polymerization conditions were controlled so that the number average molecular weight (Mn) of the final block copolymer was about 39,400 g/mol, and the volume fraction of the polymer segment A with 12 chain-forming atoms (the number of carbon atoms of R in Formula A) derived from the monomer (A) of Preparation Example 1 was about 0.47 and the volume fraction of the polymer segment B derived from the pentafluorostyrene monomer was about 0.53. The surface energy and density of the polymer segment A in the block copolymer were 30.83 mN/m and 1 g/cm.sup.3, respectively, and the surface energy and density of the polymer segment B were 24.4 mN/m and 1.57 g/cm.sup.3, respectively. Also, the result calculated by substituting the number of chain-forming atoms (12) in the polymer segment A in the block copolymer and the scattering vector value (q) at which the peak having the largest peak area in the scattering vector range of 0.5 nm.sup.−1 to 10 nm.sup.−1 was identified upon the X-ray diffraction analysis into the equation nq/(2xit), respectively, was about 3.75.

(45) Preparation Example 4. Synthesis of Random Copolymer (A)

(46) 0.5340 g of the monomer (A) of Preparation Example 1, 1.1367 g of pentafluorostyrene, 30.0 mg of an RAFT (reversible addition-fragmentation chain transfer) agent (2-hydroxyethyl 2-((dodecylthio)carbonothioyl)thio)-2-methylpropanoate), 5.1 mg of AIBN (azobisisobutyronitrile) as a radical initiator and 1.67 mL of anisole were placed in a 10 mL Schlenk flask, stirred at room temperature for 30 minutes under a nitrogen atmosphere, and then an RAFT (reversible addition-fragmentation chain transfer) was performed at 70° C. for 12 hours. After the polymerization, the reaction solution was precipitated in 250 mL of methanol as an extraction solvent, and then filtered under reduced pressure and dried to prepare a random copolymer.

(47) The number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) of the random copolymer were 12,300 g/mol and 1.17, respectively. Also, in the random copolymer, the volume fraction of the monomer unit of Preparation Example 1 was 0.48, and the volume fraction of the pentafluorostyrene unit was about 0.52.

(48) Preparation Example 5. Synthesis of Random Copolymer (B)

(49) A random copolymer was prepared in the same manner as in Preparation Example 4, except that the polymerization conditions were controlled so that in the random copolymer, the volume fraction of the monomer unit in Preparation Example 1 was 0.5 and the volume fraction of pentafluorostyrene unit was about 0.5.

EXAMPLE 1

(50) The substrate on which the trench was formed was prepared in the following manner. As a substrate, a silicon wafer substrate was applied, and a SiO.sub.2 layer was formed on the substrate to a thickness of about 200 nm by a known deposition method. Subsequently, a BARC (bottom anti-reflective coating) was coated on the SiO.sub.2 layer to a thickness of about 60 nm and a PR (photoresist) layer (KrF positive-tone resist layer) was again coated on the upper part to a thickness of about 400 nm. Subsequently, the PR layer was patterned by a KrF stepper exposure method. Subsequently, using the patterned PR layer as a mask, the lower BARC layer and SiO.sub.2 layer were etched by an RIE (reactive ion etching) method and the mesa structures were formed by removing the residue of the BARC layer and the PR layer. The distance (D) between mesa structures formed in this manner was about 150 nm, the height (H) was about 100 nm, and the width (W) of each mesa structure was about 150 nm.

(51) The random copolymer (B) of Preparation Example 5 was coated to a thickness of about 40 nm on all the bottom portion and sidewalls of the trench structure thus formed, and thermally annealed at 160° C. for 24 hours to form a polymer film. The substrate on which the polymer film was formed was treated with ultrasonic dispersion in a fluorobenzene solution for about 10 minutes to remove unreacted materials. Using the block copolymer (A) of Preparation Example 2, the polymer film was formed on the substrate in which the random copolymer film was formed in this manner. Specifically, a coating liquid prepared by diluting the block copolymer in toluene to a solid concentration of about 1.5 wt % was spin-coated in the trench of the substrate to a thickness of about 25 nm, dried at room temperature for about 1 hour, and then thermally annealed at about 160° C. for about 1 hour to form a self-assembled film. For the formed film, an SEM (scanning electron microscope) image was photographed. FIG. 4 is an SEM image of the self-assembled film. The self-assembled film formed a vertically oriented lamellar phase. It can also be confirmed from FIG. 4 that the self-assembled film is effectively guided by the trenches.

EXAMPLE 2

(52) The process was performed in the same manner as in Example 1, except that the random copolymer (A) of Preparation Example 4 was used as the random copolymer and the copolymer (B) of Preparation Example 3 was used as the block copolymer. FIG. 5 is an SEM image of the self-assembled film. The self-assembled film formed a vertically oriented lamellar phase. It can also be confirmed from FIG. 5 that the self-assembled film is effectively guided by the trenches.