Polymer composition

Abstract

A polymer composition, methods and a use thereof are disclosed herein. The polymer composition having excellent self-assembly properties and capable of forming a vertical orientation structure even on a surface that no neutral treatment is performed, where the vertically oriented self-assembled structure can be effectively formed in a short time.

Claims

1. A polymer composition, comprising: a first block copolymer having a polymer segment A and a polymer segment B; and a second block copolymer having a polymer segment C and a polymer segment D, wherein the second block copolymer having a number average molecular weight (M2) lower than a number average molecular weight (M1) of the first block copolymer, wherein the polymer segments A and C each comprise a side chain having 8 or more chain-forming atoms.

2. The polymer composition according to claim 1, wherein a ratio of M1 to M2 is in a range of 1.05 to 10.

3. The polymer composition according to claim 2, wherein M1 is in a range of 30 to 150 Kg/mol.

4. The polymer composition according to claim 2, wherein M2 is in a range of 10 to 80 Kg/mol.

5. The polymer composition according to claim 1, wherein a difference between M1 and M2 is less than 100 kg/mol.

6. The polymer composition according to claim 1, wherein the second block copolymer in the polymer composition has the lowest number average molecular weight and the second block copolymer has a weight ratio in a range of 25% to 90%, based on the total weight of all the block copolymers in the polymer composition.

7. The polymer composition according to claim 1, wherein the second block copolymer in the polymer composition has the lowest number average molecular weight, and the second block copolymer has a molar ratio in a range of 40% to 90%, based on the total mole number of all the block copolymers in the polymer composition.

8. The polymer composition according to claim 1, wherein the polymer segments A and C each have a side chain and exhibit an X-ray diffraction peak having a half-height width in a range of 0.2 to 1.5 nm.sup.−1 in a scattering vector range of 0.5 to 10 nm.sup.−1.

9. The polymer composition according to claim 1, wherein the absolute value of the difference in surface energy of the polymer segments A and B and the absolute value of the difference in surface energy of the polymer segment C and D are each in a range of 2.5 to 7 mN/m.

10. The polymer composition according to claim 1, wherein the sum of volume fractions of the polymer segments A and C is in a range of 0.3 to 0.6, and the sum of volume fractions of the polymer segments A, B, C and D is 1.

11. The polymer composition according to claim 1, wherein the polymer segments A and C each comprise a ring structure and the side chain is substituted on the ring structure.

12. The polymer composition according to claim 1, wherein the polymer segments B and D each comprise three or more halogen atoms.

13. The polymer composition according to claim 12, wherein the polymer segments B and D each comprise a ring structure and the halogen atoms are substituted on the ring structure.

14. A laminate, comprising: a substrate; and a polymer film in contact with the substrate, wherein the polymer film comprises the polymer composition of claim 1, wherein the first and second block copolymers form a self-assembled structure in the polymer film, and wherein the surface of the substrate that the polymer film contacts is not subjected to neutral treatment prior to contact with the polymer film.

15. The laminate according to claim 14, wherein the self-assembled structure is vertically oriented.

16. A method for producing a patterned substrate, comprising: selectively removing any one polymer segment from the block copolymers forming the self-assembled structure in the polymer film of the laminate of claim 14 to expose a surface of the substrate, the exposed surface of the substrate underlying the portion of the polymer film that is removed.

17. The method for producing a patterned substrate according to claim 16, further comprising: etching the exposed surface of the substrate using the polymer film as a mask.

18. A polymer composition, comprising: a first block copolymer having a polymer segment A and a polymer segment B; and a second block copolymer having a polymer segment C and a polymer segment D, wherein the second block copolymer having a number average molecular weight (M2) lower than a number average molecular weight (M1) of the first block copolymer, wherein the polymer segments A and C each have a side chain and exhibit an X-ray diffraction peak having a half-height width in a range of 0.2 to 1.5 nm.sup.−1 in a scattering vector range of 0.5 to 10 nm.sup.−1.

19. A polymer composition, comprising: a first block copolymer having a polymer segment A and a polymer segment B; and a second block copolymer having a polymer segment C and a polymer segment D, wherein the second block copolymer having a number average molecular weight (M2) lower than a number average molecular weight (M1) of the first block copolymer, wherein the absolute value of the difference in surface energy of the polymer segments A and B and the absolute value of the difference in surface energy of the polymer segment C and D are each in a range of 2.5 to 7 mN/m.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The FIGURE is an SEM photograph of the polymer film of Example 1.

MODE FOR INVENTION

(2) 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.

(3) 1. NMR Measurement

(4) 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.

(5) <Application Abbreviation>

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

(7) 2. GPC (Gel Permeation Chromatograph)

(8) 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.

(9) <GPC Measurement Condition>

(10) Instrument: 1200 series from Agilent Technologies

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

(12) Solvent: THF

(13) Column temperature: 35° C.

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

(15) Standard samples: polystyrene (Mp: 3900000, 723000, 316500, 52200, 31400, 7200, 3940, 485)

(16) 3. XRD Analysis Method

(17) 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 block copolymer in a powder state dried by purifying a synthesized block copolymer 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-height 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-height width were obtained from the fitted results. Upon Gaussian fitting, the R square was at least set to be 0.96 or more.

(18) 4. Measurement of Surface Energy

(19) 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 weight %, 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.

(20) 5. Measurement of Volume Fraction

(21) The volume fraction of each polymer segment of the block copolymer was calculated based on the density of each polymer segment at room temperature and the molecular weight measured by GPC. Here, the density was measured using a buoyancy method, and specifically, it was calculated by placing a sample to be analyzed in a solvent (ethanol) to know the mass and density in air, and measuring the mass.

Preparation Example 1. Synthesis of Monomer (A)

(22) A compound (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 DCM (dichloromethane) in column chromatography.

(23) <NMR Analysis Result>

(24) .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).

(25) 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%.

(26) <NMR Analysis Result>

(27) .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); δd 2.05 (dd, 3H); d1.76 (p, 2H); δd1.43 (p, 2H); 1.34-1.27 (m, 16H); d0.88 (t, 3H).

(28) ##STR00005##

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

Preparation Example 2. Synthesis of Block Copolymer (A)

(30) 6.0 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 weight %, and the number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) were 29 Kg/mol and 1.16, respectively. 0.3 g of the macro initiator, 10 g of a pentafluorostyrene monomer and 5 mL of benzene were placed in a 50 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 weight %, and the number average molecular weight (Mn) and the molecular weight distribution (Mw/Mn) were 73 Kg/mol and 1.13, respectively. The block copolymer comprises a polymer segment A derived from the monomer (A) of Preparation Example 1 and a polymer segment B derived from the pentafluorostyrene monomer.

Preparation Examples 3 to 5

(31) Three kinds of block copolymers having different molecular weights were further prepared in the same manner as in Preparation Example 1 except for controlling the molar ratios of the monomer and the macro initiator, and the like. The characteristics of the macro initiator and the block copolymer used in each preparing process were summarized and described in Table 1 below.

(32) TABLE-US-00001 TABLE 1 Preparation Example 2 3 4 5 Block copolymer A B C D Macro Molecular weight (Mn) 29 21 8 6 initiator Molecular weight distribution 1.16 1.2 1.11 1.19 Block Molecular weight (Mn) 73 68 23 21 copolymer Molecular weight distribution 1.13 1.1 1.15 1.21 Volume fraction 0.49 0.58 0.56 0.64 Molecular weight (Mn): number average molecular weight (unit: Kg/mol) Molecular weight distribution (Mw/Mn): ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) Volume fraction: volume fraction of polymer segment B (the total volume fraction of segments A and B is 1)

(33) The block copolymers (A) to (D) prepared above all contain a side chain having 12 chain-forming atoms in the segment A (the R moiety of Formula A above). Furthermore, for each block copolymer, the value of n/D, that is, the numerical value calculated by nq/(2×π) in Equation 1 above (in Equation 1 above, n is the number of chain-forming atoms (12), q is the scattering vector value at which the peak with the largest peak area is identified in the scattering vector range of 0.5 nm.sup.−1 to 10 nm.sup.−1) was about 3.75 for all, the surface energy of the polymer segment A was about 30.83 mN/m in all the four block copolymers, and the surface energy of the polymer segment B was also about 24.4 mN/m in all the four block copolymers. In addition, the density of the polymer segment A was about 1 g/cm.sup.3 in all the four block copolymers, and the density of the polymer segment B was about 1.57 g/cm.sup.3.

Example 1

(34) The block copolymer (A) of Preparation Example 2 and the block copolymer (C) of Preparation Example 4 were mixed to prepare a polymer composition. The ratio of the block copolymer (A) in the polymer composition was 75 weight %, and the ratio of the block copolymer (C) was 25 weight %. Subsequently, a coating liquid prepared by diluting the polymer composition in toluene to a solid concentration of about 1.5 weight % was spin-coated on a substrate, dried at room temperature for about 1 hour, and then thermally annealed at a temperature of about 200° C. for about 10 minutes to form a self-assembled film. Here, as the substrate, a known silicon wafer without any neutral treatment on its surface was applied. An SEM (scanning electron microscope) image of the formed film was photographed. The FIGURE is an SEM image photographed in Example 1, and as confirmed from the drawing, it was confirmed that in the case of the polymer composition of Example 1, the vertically oriented self-assembled lamellar structure was effectively formed.

Example 2

(35) A polymer film was formed in the same manner as in Example 1 except that the ratio of the block copolymer (A) in the polymer composition was 60 weight % and the ratio of the block copolymer (C) was 40 weight %, and the evaluation results thereof were summarized and described in Table 2 below.

Example 3

(36) A polymer film was formed in the same manner as in Example 1 except that the ratio of the block copolymer (A) in the polymer composition was 40 weight % and the ratio of the block copolymer (C) was 60 weight %, and the evaluation results thereof were summarized and described in Table 2 below.

Example 4

(37) A polymer film was formed in the same manner as in Example 2 except that the block copolymer (D) was applied instead of the block copolymer (C), and the evaluation results thereof were summarized and described in Table 2 below.

Example 5

(38) A polymer film was formed in the same manner as in Example 2 except that the block copolymer (B) was applied instead of the block copolymer (A), and the evaluation results thereof were summarized and described in Table 2 below.

Example 6

(39) A polymer film was formed in the same manner as in Example 5 except that the block copolymer (D) was applied instead of the block copolymer (C), and the evaluation results thereof were summarized and described in Table 2 below.

Comparative Example 1

(40) A polymer film were formed in the same manner as in Example 1 by applying only the block copolymer (A), and the evaluation results thereof were summarized and described in Table 2 below.

(41) TABLE-US-00002 TABLE 2 Comparative Example Example 1 2 3 4 5 6 1 Polymer First BCP A A A A B B A composition Second BCP C C C D C D — Wt % 25 40 60 40 40 40 — Mol % 52 68 83 70 67 69 — VF 0.51 0.51 0.53 0.55 0.57 0.60 0.49 Phase separation formed formed formed formed formed formed unformed Pitch 47 38 28 35 33 31 First BCP: type of first block copolymer Second BCP: type of second block copolymer Wt %: weight ratio of second block copolymer in the polymer composition (unit: weight %) (based on 100 weight % of the total weight of the first and second block copolymer) Mol %: molar fraction of the second block copolymer in the polymer composition (unit: weight %) (based on 100 mol % of the total mole number of the first and second block copolymers) VF: total volume fraction of polymer segments B and D in the polymer composition (based on 1 of the sum of polymer segments A, B, C and D) Phase separation: whether or not a vertically oriented lamellar structure is formed in the same form as in the FIG of Example 1 (in the case of Comparative Example 1, a horizontal orientation phase separation structure is formed) Pitch: distance between lamella centers in vertically oriented lamellar structure (unit: nm)