Polymer material, self-assembled film, method for producing self-assembled film, pattern, and method for forming pattern

Abstract

To provide a polymeric material which reduces the amount of expensive compounds used and can form a self-assembled monolayer excellent in etch resistance.SOLUTION: The polymeric material contains a multi-block copolymer formed by linking first and second polymerization blocks. The first polymerization block is a random copolymer comprising: a styrene unit having a substituent represented by the general formula (2) in the figure at the para position and having a hydrogen atom or C1-3 alkyl group at the α-position; and a styrene unit having a hydrogen atom or C1-3 alkyl group at the α-position. The second polymerization block comprises a styrene unit having a hydroxy group at the para position and having a hydrogen atom or C1-3 alkyl group at the α-position. In the first polymerization block, the content of the styrene unit having a hydrogen atom or C1-3 alkyl group at the α-position is 10-80 mol% based on the total amount of the first polymerization block. [In the general formula (2), b is an integer from 2 to 8 inclusive.]SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer material, a self-assembled film, a method for producing a self-assembled film, a pattern, and a method for forming a pattern. [Background technology]

[0002] As electronic components, including semiconductors, become smaller, there is an increasing demand for lithography technology that can form fine patterns.

[0003] In particular, technology using directed self-assembly (DSA) that utilizes microphase separation of block copolymers is attracting attention as a next-generation lithography technology because it is capable of forming fine patterns at low cost.

[0004] As an example of such a technique, Patent Document 1 discloses a polymer film in which a block copolymer resin, which is formed by bonding at least two or more types of mutually incompatible polymers at their terminals, is placed on a substrate having a surface roughness of at least 1 nm, and the block copolymer film has a microdomain structure oriented perpendicular to the substrate surface, and the block copolymer resin is a mixture of at least two or more types of block copolymer resins having different molecular weights. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-8701 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have found that when conventional directed self-assembly materials are etched to form a pattern, the polymer film is thinned, making it impossible to form a pattern with the desired shape (insufficient etching resistance).

[0007] As a result of further investigation, the present inventors have found that a multiblock copolymer containing a structural unit represented by the general formula (1) described below (for example, 4-pentamethyldisilylstyrene) has a property in which the polymer blocks containing the structural unit represented by the general formula (1) exhibit vertical stacking, and can improve etching resistance. However, the compounds forming the structural units represented by the general formula (1) are very expensive, and cost remains an issue.

[0008] The present invention has been made in view of the above-mentioned problems, and aims to provide a polymeric material that can form a self-assembled film having excellent etching resistance while reducing the amount of compound that forms a constitutional unit represented by general formula (1) described below. [Means for solving the problem]

[0009] As a result of intensive research into the above-mentioned problems, the present inventors have found that a multiblock copolymer formed by linking a first polymerization block, which is a random copolymer containing a constitutional unit represented by the general formula (1) described below and a constitutional unit represented by the general formula (3) described below, with a second polymerization block containing a constitutional unit represented by the general formula (4) described below, has a property in which the constituent portions of the first polymerization block exhibit vertical stacking, and that by utilizing this property, etching resistance can be improved. Furthermore, the present inventors have found that by including a predetermined weight ratio of the structural unit represented by general formula (3) described below that constitutes the first polymer block, it is possible to reduce the amount of the compound that forms the structural unit represented by general formula (1) described below, while maintaining the above-mentioned etching resistance, thereby arriving at the present invention.

[0010] That is, the present invention provides a multiblock copolymer comprising a first polymer block, which is a random copolymer comprising a constitutional unit represented by the following general formula (1) and a constitutional unit represented by the following general formula (3), linked to a second polymer block comprising a constitutional unit represented by the following general formula (4), wherein the first polymer block comprises 10 to 80 mol % of the constitutional unit represented by the following general formula (3) relative to the entire first polymer block; a self-assembled film obtained using the polymer material; a method for producing a self-assembled film that forms a self-assembled film using the polymer material; a pattern obtained by etching the self-assembled film; and a method for forming a pattern, including the step of etching the self-assembled film to form a pattern.

[0011] [ka] [In general formula (1), R 1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, a is an integer of 1 or more and 1000 or less, and X is a substituent represented by general formula (2). [ka] [In general formula (2), b is an integer of 2 or more and 8 or less.] [ka] [In general formula (3), R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and c is an integer of 1 or more and 1000 or less. [ka] [In general formula (4), R 3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and d is an integer of 1 or more and 1000 or less. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a polymeric material that can form a self-assembled film having excellent etching resistance while reducing the amount of compound that forms the constitutional unit represented by the above general formula (1) to be used. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Polymer materials> The polymer material of the present invention contains a multiblock copolymer in which a first polymer block is a random copolymer containing a constitutional unit represented by the following general formula (1) and a constitutional unit represented by the following general formula (3), and a second polymer block containing a constitutional unit represented by the following general formula (4) is linked together, and the first polymer block contains 10 to 80 mol % of the constitutional unit represented by the general formula (3) relative to the entire first polymer block.

[0014] [ka] [In general formula (1), R 1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, a is an integer of 1 or more and 1000 or less, and X is a substituent represented by general formula (2). [ka] [In general formula (2), b is an integer of 2 or more and 8 or less.] [ka] [In general formula (3), R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and c is an integer of 1 or more and 1000 or less. [ka] [In general formula (4), R 3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and d is an integer of 1 or more and 1000 or less.

[0015] Directed self-assembly (DSA) technology utilizes the ability to form microphase separation, which occurs when two incompatible polymer chains are linked at a single point through copolymerization. In multiblock copolymers linked by covalent bonds, when identical polymer components aggregate intermolecularly and undergo microphase separation, the interfacial curvature during molecular aggregation changes depending on the volume fraction ratio (f) between the two polymer components, resulting in a change in the microdomain structure.

[0016] Known microdomain structures formed by two polymer components (e.g., a first polymer block and a second polymer block) include a spherical structure in which the first polymer block is finely dispersed in the second polymer block, a cylindrical structure in which the first polymer block is linearly dispersed in the second polymer block, a gyroid structure in which multiple first polymer blocks dispersed in the second polymer block are bonded to each other, and a lamellar structure in which the second polymer block and the first polymer block are laminated in layers. The polymer material of the present invention may exhibit any of the above microdomain structures, but from the viewpoint of semiconductor pattern formation, it is preferable that the polymer material exhibit a lamellar structure or a cylindrical structure. First, the first polymer block will be described.

[0017] (First polymer block) The first polymer block is a random copolymer containing a constitutional unit represented by the above general formula (1) and a constitutional unit represented by the above general formula (3).

[0018] R in the above general formula (1) 1 and R in the general formula (3) 2 There are no particular restrictions on the alkyl group, as long as it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Among these, R 1 , and R 2As the group, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred, from the viewpoint of being able to reduce defects due to poor microphase separation sites and to form fine and minute repeated patterns.

[0019] In the above general formula (2), b is an integer of 2 or more and 8 or less. From the viewpoint of reducing the half pitch (hp), b is preferably 2 or 3, and more preferably 2.

[0020] The first polymer block contains 10 to 80 mol % of the constitutional unit represented by the above general formula (3) based on the entire first polymer block. By including the constitutional unit represented by general formula (3) above in the above ratio relative to the entire first polymer block, the amount of the compound forming the constitutional unit represented by general formula (1) used can be suitably reduced, and the resulting multiblock copolymer can have vertical stacking properties and be suitably imparted with etching resistance. The first polymer block preferably contains 20 to 70 mol %, and more preferably 25 to 60 mol %, of the structural unit represented by the above general formula (3) relative to the entire first polymer block.

[0021] The first polymer block may further include a constitutional unit represented by the following general formula (5).

[0022] [ka] [In general formula (5), R 4 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and e is an integer of 1 or more and 1000 or less.

[0023] R in the above general formula (5) 4 is not particularly limited as long as it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and 1 , and R 2 The substituents exemplified in can be applied. Among these, R 4As the group, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred, from the viewpoint of being able to reduce defects due to poor microphase separation sites and to form fine and minute repeated patterns.

[0024] The first polymer block may contain 0 to 35 mol % of the constitutional unit represented by the above general formula (5) based on the entire first polymer block.

[0025] The first polymer block may be, for example, a first polymer block A obtained by repeatedly randomly polymerizing a constitutional unit represented by the general formula (1) above and a constitutional unit represented by the general formula (3) above, or a first polymer block B obtained by repeatedly randomly polymerizing a constitutional unit represented by the general formula (1) above, a constitutional unit represented by the general formula (3) above, and a constitutional unit different from the general formulas (1) and (3) above (for example, a constitutional unit represented by the general formula (5) above).

[0026] (Second polymer block) The second polymer block contains a constitutional unit represented by the above general formula (4).

[0027] R in the above general formula (4) 3 There are no particular restrictions on the alkyl group, as long as it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Among these, R 3 As the group, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred, from the viewpoint of being able to reduce defects due to poor microphase separation sites and to form fine and minute repeated patterns.

[0028] As the second polymer block, for example, a second polymer block C formed by repeatedly polymerizing the same structural unit represented by the above general formula (4), or a second polymer block D formed by repeatedly polymerizing a structural unit represented by the above general formula (4) and a structural unit different from the above general formula (4) can be used. Examples of structural units different from those of the general formula (4) include structural units represented by the general formula (3) above.

[0029] The second polymer block preferably contains 90 mol % or more, and more preferably 100 mol % of the constitutional unit represented by the general formula (4) relative to the entire second polymer block.

[0030] (multiblock copolymer) The multiblock copolymer is formed by linking the above-mentioned first polymer block and second polymer block.

[0031] The multi-block copolymer is preferably a di-block or higher block copolymer.

[0032] As the diblock copolymer, a copolymer in which the above-mentioned first polymer blocks A and B and second polymer blocks C and D are arranged in any order such as AC, AD, BC, or BD can be used. From the viewpoint of being able to reduce defects due to poor microphase separation sites and being able to form fine and minute repeating patterns, preferred is an arrangement of a first polymer block A formed by the repeated random polymerization of a constitutional unit represented by the above general formula (1) and a constitutional unit represented by the above general formula (3), and a second polymer block C formed by the repeated polymerization of the same constitutional unit represented by the above general formula (4).

[0033] Even when the multiblock copolymer is a triblock copolymer or greater, from the viewpoint of reducing defects due to poor microphase separation sites and enabling the formation of fine and minute repeating patterns, it is preferable that the first polymer blocks A and the second polymer blocks C are arranged alternately, for example, in the form of (ACA), (CAC), (ACACAC), or (CACACA).

[0034] Preferably, the multi-block copolymer is a hexa-block copolymer or smaller. This is because it is difficult to synthesize a heptablock copolymer or a multiblock copolymer.

[0035] Regarding the ratio of the constituent units of the multiblock copolymer, from the viewpoint of improving the uniformity and regularity of the pattern of the microdomain structure formed by self-assembly, the molar ratio of the first polymer block to the second polymer block (moles of the first polymer block:moles of the second polymer block) is preferably within the range of 8:2 to 2:8.

[0036] When the above-mentioned lamellar structure or cylindrical structure is preferably formed, the molar ratio of the first polymer block to the second polymer block (moles of the first polymer block:moles of the second polymer block) is more preferably within the range of 4:6 to 6:4, and even more preferably 5:5, from the viewpoint of improving the uniformity and regularity of the pattern of the microdomain structure formed by self-assembly.

[0037] The multiblock copolymer preferably has a number average molecular weight (Mn) of 3,000 or more and 50,000 or less, from the viewpoint of improving the uniformity and regularity of the pattern of the microdomain structure formed by self-assembly. If the number-average molecular weight (Mn) is 3,000 or more, self-assembly proceeds to form a self-assembled film with a microdomain structure. If the number-average molecular weight (Mn) is 50,000 or less, the hydrogen bonds of the hydrophilic groups of the polymer compound function appropriately, making it easy to achieve a pattern size of 8.0 nm or less. The number average molecular weight (Mn) is more preferably at least 5,000, and even more preferably at least 6,000. The number average molecular weight (Mn) is more preferably at most 20,000.

[0038] The molecular weight distribution (PDI: Mw / Mn=PDI) of the multiblock copolymer is preferably 1.0 or more, more preferably 1.02 or more, and is preferably 1.1 or less, more preferably 1.05 or less, from the viewpoint of being able to reduce defects due to poor microphase separation sites and to form fine and minute repeating patterns. If the PDI is 1.0 or more and 1.1 or less, there is almost no inclusion of low-molecular-weight polymers and high-molecular-weight polymers, and therefore the uniformity and regularity of the pattern of the microdomain structure formed by self-organization are improved.

[0039] The number average molecular weight (Mn) and PDI (and weight average molecular weight Mw) are measured by gel permeation chromatography (GPC) using polystyrene as the standard. The number average molecular weight measured by GPC is measured at a column temperature of 40°C using, for example, a GPC measuring device (trade name: HLC-8120, manufactured by Tosoh Corporation), a column (trade name: TSK GELGMH6, manufactured by Tosoh Corporation), and a mobile phase (THF), and calculated using a calibration curve of standard polystyrene.

[0040] The composition ratio of the multiblock copolymer can be determined by nuclear magnetic resonance (NMR) spectroscopy. The composition ratio by NMR can be measured, for example, using an NMR measurement device (trade name "JNM-ECZ400R", manufactured by JEOL, analysis software: Delta5.3.1, frequency: 400 MHz), at a temperature of 25°C, solvent (CDCl3), internal standard: tetramethylsilane (TMS), and with 16 accumulations. The composition of the multiblock copolymer means the constituent units that make up the multiblock copolymer, and the composition ratio means the molar ratio of the constituent units that make up the multiblock copolymer.

[0041] The multi-block copolymer is preferably copolymerized by living anionic polymerization. A multiblock copolymer having a first polymerization block mainly composed of a constitutional unit represented by the general formula (1) above and a constitutional unit represented by the general formula (3) above, which are copolymerized by living anionic polymerization, and a second polymerization block mainly composed of a constitutional unit represented by the general formula (4) above is preferred. By copolymerizing polymer materials using living anionic polymerization, it is possible to narrow the PDI and precisely obtain polymer compounds with the desired number-average molecular weight, which enables the uniformity and regularity of the microdomain structure patterns formed by self-organization to be improved.

[0042] There are no particular limitations on the method for producing a polymer compound that is a multiblock copolymer, as long as it is capable of copolymerizing a first polymer block and a second polymer block. Polymerization methods for obtaining polymeric materials include living anionic polymerization, living cationic polymerization, living radical polymerization, and coordination polymerization using an organometallic catalyst. Among these, living anionic polymerization is preferred because it causes less deactivation and side reactions during polymerization and allows living polymerization.

[0043] In living anionic polymerization, a polymerization monomer and an organic solvent that have been subjected to deoxidation and dehydration treatment are used. Examples of organic solvents include hexane, cyclohexane, toluene, benzene, diethyl ether, and tetrahydrofuran. In living anionic polymerization, a required amount of anionic species is added to these organic solvents, and then monomers are added as needed to carry out polymerization. Examples of anionic species include organic metals such as alkyllithium, alkylmagnesium halide, sodium naphthalene, and alkylated lanthanoid compounds. Since a substituted styrene is copolymerized as a monomer, among these, s-butyllithium and butylmagnesium chloride are preferred as the anion species. The polymerization temperature for living anionic polymerization is preferably within the range of -100°C or higher and 50°C or lower, and from the viewpoint of facilitating control of the polymerization, it is more preferably -70°C or higher and 40°C or lower.

[0044] As a method for producing a block copolymer (first polymer block) having a constitutional unit represented by the general formula (1) above and a constitutional unit represented by the general formula (3) above, for example, a compound that imparts a constitutional unit represented by the general formula (1) above, such as 4-pentamethyldisilylstyrene, and a compound that imparts a constitutional unit represented by the general formula (3) above, such as styrene, are subjected to living anionic polymerization under the conditions described above to synthesize the block copolymer. As a method for producing a block copolymer (second polymer block) having a constitutional unit represented by general formula (4), for example, a block copolymer is synthesized by living anionic polymerization of a substituted styrene monomer in which a phenolic hydroxyl group is protected, such as p-(1-ethoxyethoxy)styrene, under the conditions described above. This block copolymer can deprotect the phenolic hydroxyl groups of the resulting polymer compound using an acid catalyst such as oxalic acid. Protective groups for the phenolic hydroxyl groups during polymerization include p-(1-ethoxyethoxy) groups, as well as t-butyl groups and trialkylsilyl groups. When a monomer having another ether moiety or ester moiety is copolymerized in a polymer compound, it is also possible to obtain a phenolic hydroxyl group by selectively deprotecting the phenolic hydroxyl group by adjusting the acidity during the deprotection reaction and conducting the deprotection reaction under alkaline conditions.

[0045] <Self-assembled membrane> The self-assembled film of the present invention can be obtained using the polymer material of the present invention described above. The polymer material of the present invention is preferably used for self-assembly (formation of a self-assembled film) because it can form a self-assembled film that has a small and uniform half pitch (hp) of the pattern to be formed, has film strength, and has excellent etching resistance during dry etching.

[0046] The self-assembled film of the present invention can be obtained by dissolving the polymer material of the present invention in an organic solvent and applying the solution.

[0047] The organic solvent is not particularly limited as long as it can form a self-assembled monolayer, and examples thereof include butyl acetate, amyl acetate, cyclohexyl acetate, 3-methoxybutyl acetate, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, cyclopentanone, 3-ethoxyethyl propionate, 3-ethoxymethyl propionate, 3-methoxymethyl propionate, methyl acetoacetate, ethyl acetoacetate, diacetone alcohol, methyl pyruvate, ethyl pyruvate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monomethyl ether propionate. Examples of the solvent include propylene glycol monoethyl ether propionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, 3-methyl-3-methoxybutanol, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, methyl lactate, ethyl lactate, propyl lactate, and tetramethylene sulfone. These solvents may be used alone or in combination of two or more.

[0048] The organic solvent is preferably propylene glycol alkyl ether acetate or alkyl lactate. Examples of the propylene glycol alkyl ether acetate include those having an alkyl group with 1 to 4 carbon atoms. Examples of such alkyl groups include methyl, ethyl, propyl, and butyl. Among these, methyl and ethyl are preferred. Furthermore, propylene glycol alkyl ether acetate has three isomers depending on the combination of substitution positions, including 1,2-substituted and 1,3-substituted isomers. These isomers may be used alone or two or more isomers may be used in combination.

[0049] Examples of alkyl lactate esters include those in which the number of carbon atoms in the alkyl group is 1 to 4. Examples of such alkyl groups include methyl, ethyl, propyl, and butyl groups. Among these, methyl and ethyl groups are preferred.

[0050] Regarding the concentration of the organic solvent, for example, when propylene glycol alkyl ether acetate is used, the propylene glycol alkyl ether acetate is preferably 50% by mass or more relative to the total mass of the organic solvent, and when alkyl lactate is used, the propylene glycol alkyl ether acetate is preferably 50% by mass or more relative to the total mass of the organic solvent. When a mixed solvent of propylene glycol alkyl ether acetate and alkyl lactate is used as the organic solvent, the total amount of the mixed solvent is preferably 50% by mass or more based on the total mass of the organic solvent. When using this mixed solvent, it is preferable to use propylene glycol alkyl ether acetate in a proportion of 60% by mass to 95% by mass and alkyl lactate in a proportion of 5% by mass to 40% by mass. By using propylene glycol alkyl ether acetate in a proportion of 60% by mass or more, the coatability of the polymer material is improved, and by using propylene glycol alkyl ether acetate in a proportion of 95% by mass or less, the solubility of the polymer material is improved.

[0051] The concentration of the solution in which the polymer material of the present invention is dissolved in an organic solvent is not particularly limited, as long as it allows a self-assembled film to be obtained by a conventionally known film-forming method. For example, the organic solvent is preferably 5,000 parts by mass or more and 50,000 parts by mass or less, and more preferably 7,000 parts by mass or more and 30,000 parts by mass or less, per 100 parts by mass of the solid content of the polymer material.

[0052] The self-assembled film of the present invention can be produced by applying a solution in which the polymer material of the present invention is dissolved in an organic solvent. The method for applying the solution in which a polymer material is dissolved in an organic solvent is not particularly limited as long as it can produce a self-assembled film, and examples thereof include spin coating, dipping, flexographic printing, inkjet printing, spraying, potting, and screen printing. The present invention also encompasses a method for producing a self-assembled film by forming a self-assembled film using the polymer material of the present invention.

[0053] The self-assembled film of the present invention is preferably coated on its surface with a top coating agent from the viewpoint of improving the handling properties and weather resistance of the self-assembled film, since the self-assembled film is sealed and protected.

[0054] Examples of the top coating agent include polyester-based top coating agents, polyamide-based top coating agents, polyurethane-based top coating agents, epoxy-based top coating agents, phenol-based top coating agents, (meth)acrylic-based top coating agents, polyvinyl acetate-based top coating agents, polyolefin-based top coating agents such as polyethylene aluminum and polypropylene, and cellulose-based top coating agents. The coating amount of the above top coating agent (solid content equivalent) is 3 g / m 2 More than 7g / m 2 The following is preferred: The above-mentioned top coating agent can be applied onto the self-assembled monolayer by a conventionally known application method. The present invention also encompasses a method for producing a self-assembled film, which includes a step of applying a top coating agent onto the self-assembled film.

[0055] The self-assembled film of the present invention may be coated with an undercoating agent. As the undercoating agent, various conventionally known undercoating agents can be used.

[0056] The self-assembled film of the present invention preferably forms a self-assembled film within a guide pattern. In this case, for example, a solution of a polymer material can be applied to a silicon substrate with a guide pattern to form a self-assembled film. Then, a pattern of the self-organized microdomain structure is obtained on the silicon substrate by annealing at 200° C. to 300° C. for 5 minutes to 1 hour. By etching the resulting microdomain structure pattern with oxygen plasma gas, an L / S (line / space) pattern and a CH (fine hole) pattern with a half pitch (hp) of 10.0 nm or less can be obtained. The present invention also encompasses a pattern formed by etching the self-assembled film, and a method for forming a pattern including the step of etching the self-assembled film to form a pattern.

[0057] The cohesive strength of the multiblock copolymer can be evaluated by transmission electron microscope (TEM) observation and small-angle X-ray scattering (SAXS) measurement. A sample for evaluating cohesive strength can be prepared, for example, by preparing a 50 mg sample film of the multiblock copolymer, dissolving the prepared sample in 1 g of additive-free THF, transferring the sample to a Teflon petri dish, casting it in the Teflon petri dish for 10 days, and vacuum drying it.

[0058] For TEM observation, first, the sample film is cut to an appropriate size and placed in an embedding mold, then epoxy resin is poured into it and left to stand at 60°C for 12 hours to harden the epoxy resin and perform the embedding process. The embedded sample film is then cut into sections approximately 50 nm thick using a microtome, and the sections are then collected on Cu grids and stained with Cs2CO3 before being observed with a transmission electron microscope to measure hp.

[0059] In the SAXS measurement, for example, a block copolymer powder is heat-treated on a heat-resistant film, and microphase separation in the bulk state can be measured using a small-angle X-ray scattering (SAXS) analyzer (ultrafine periodic structure analysis system Nano-Viewer AXIS IV, manufactured by Rigaku).

[0060] In this microphase separation measurement, for example, X-rays are incident on a sample film of a block copolymer, and the angular dependence of scattering that appears on the small angle side is measured for 60 minutes using an imaging plate. Regarding measurement data processing, background correction such as air scattering is performed to obtain q / nm -1 After calculating and performing Fourier transform analysis, the half pitch (hp) of the self-assembled monolayer, which is half the identity period (d) of the average repeating pattern size width of the microdomain structure formed by self-assembly of the block copolymer, can be measured.

[0061] The present specification discloses the following:

[0062] The present disclosure (1) comprises a multiblock copolymer formed by linking a first polymerization block, which is a random copolymer containing a constitutional unit represented by the general formula (1) above and a constitutional unit represented by the general formula (3) above, with a second polymerization block containing a constitutional unit represented by the general formula (4) above, wherein the first polymerization block is a polymer material containing 10 to 80 mol % of the constitutional unit represented by the general formula (3) relative to the entire first polymerization block.

[0063] The present disclosure (2) is the polymer material according to the present disclosure (1), in which the first polymer block is represented by the general formula (2), where b is 2.

[0064] The present disclosure (3) is the polymer material according to the present disclosure (1) or (2), in which the first polymer block further contains a constitutional unit represented by the above general formula (5).

[0065] The present disclosure (4) is the polymer material according to any one of the present disclosures (1) to (3), wherein the multiblock copolymer is a diblock copolymer or greater and a hexablock copolymer or less.

[0066] The present disclosure (5) is the polymer material according to any one of the present disclosures (1) to (4), in which the multiblock copolymer is copolymerized by living anionic polymerization.

[0067] The present disclosure (6) is the polymer material according to any one of the present disclosures (1) to (5), wherein the multiblock copolymer has a number average molecular weight of 3,000 or more and 50,000 or less.

[0068] The present disclosure (7) is a self-assembled film obtained by using the polymer material according to any one of the present disclosures (1) to (6).

[0069] The present disclosure (8) is the self-assembled film according to the present disclosure (7), the surface of which is coated with a top coating agent.

[0070] The present disclosure (9) is a method for producing a self-assembled film, which uses the polymer material according to any one of the present disclosures (1) to (6) to form a self-assembled film.

[0071] The present disclosure (10) is a method for producing a self-assembled film according to the present disclosure (9), which forms a self-assembled film within a guide pattern.

[0072] The present disclosure (11) is a method for producing a self-assembled film according to the present disclosure (9) or (10), which includes a step of applying a top coating agent onto the self-assembled film.

[0073] The present disclosure (12) is a pattern obtained by etching the self-assembled film according to the present disclosure (7) or (8).

[0074] The present disclosure (13) is a method for forming a pattern, including a step of etching the self-assembled film according to the present disclosure (7) or (8) to form a pattern. [Example]

[0075] Examples and comparative examples conducted to clarify the effects of the present invention will be described below, but the present invention is not limited to the following examples and comparative examples.

[0076] Example 1: Synthesis of diblock copolymer (BP-2) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 7.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 48.0 g of 4-pentamethyldisilylstyrene that had been purified by distillation and 24.0 g of styrene was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes. Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes. Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (BP-1).

[0077] Next, 50 g of the obtained diblock copolymer (BP-1) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-2). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of the diblock copolymer (BP-2).

[0078] <Measurement of number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution (PDI) of diblock copolymer (BP-2)> The number average molecular weight and molecular weight distribution of the obtained diblock copolymer (BP-2) were measured by gel permeation chromatography (GPC). The measurement conditions are shown below. The measurement results are shown below and in Table 2 below. GPC measuring device: Product name: "HLC-8120", manufactured by Tosoh Corporation Column: Product name "TSK GEL GMH6", manufactured by Tosoh Corporation Mobile phase: THF Column temperature: 40℃ Standard material: polystyrene

[0079] As a result of GPC measurement using standard polystyrene as a standard, the obtained diblock copolymer (BP-2) had an Mn of 9089, an Mw of 9453, and a PDI of 1.04.

[0080] <Measurement of composition ratio of diblock copolymer (BP-2)> Nuclear Magnetic Resonance (NMR) spectroscopy ( 1 The composition ratio of the obtained diblock copolymer (BP-2) was measured by H-NMR under the following measurement conditions. NMR measurement device: product name "JNM-ECZ400R, manufactured by JEOL, analysis software: Delta5.3.1"); Frequency: 400MHz Temperature: 25℃, Solvent: CDCl3, Internal standard: tetramethylsilane (TMS) Accumulation count: 16 times

[0081] It was confirmed that the signals (around 3 ppm to 4 ppm and 5 ppm) derived from the 1-ethoxyethoxy group before deprotection disappeared after deprotection. Furthermore, the area ratio of each signal indicated that the composition ratio (molar ratio) of the diblock copolymer (BP-2) was [4-pentamethyldisilylstyrene (PMDSSt) + styrene (St)] (PMDSSt + St):4-hydroxystyrene (HSt) = 48:52.

[0082] In the SAXS measurement, the block copolymer powder was heat-treated on a heat-resistant film, and microphase separation in the bulk state was measured using small-angle X-ray scattering (SAXS) and an analytical device (ultrafine periodic structure analysis system: product name "Nano-Viewer AXIS IV", manufactured by Rigaku). X-rays were incident on a sample film of a block copolymer, and the angular dependence of scattering that appears on the small angle side was measured for 60 minutes using an imaging plate. Regarding measurement data processing, background correction such as air scattering was performed and the q / nm -1 was calculated, and after performing Fourier transform analysis, the half pitch (hp) of the self-assembled film, which is half the identity period (d) of the average repeat pattern size width of the microdomain structure formed by self-assembly of the block copolymer, was measured. As a result, the identity period (d) was 16.0 nm and the half pitch (hp) was 8.0 nm. The measurement results are shown in Table 2 below.

[0083] Example 2: Synthesis of diblock copolymer (BP-4) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 8.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 88.0 g of 4-pentamethyldisilylstyrene that had been purified by distillation and 5.0 g of styrene was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes. Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes. Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (BP-3).

[0084] Next, 50 g of the obtained diblock copolymer (BP-3) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-4). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of diblock copolymer (BP-4).

[0085] The composition ratio, Mn, Mw, and PDI of the diblock copolymer (BP-4) obtained were measured by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below. (4-pentamethyldisilylstyrene + styrene) (PMDSSt + St): 4-hydroxystyrene (HSt) = 48:52 Mn=9254 Mw=9624 PDI=1.04

[0086] Next, the identity period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the identity period (d) was 14.0 nm and hp was 7.0 nm. The measurement results are shown in Table 2 below.

[0087] Example 3: Synthesis of diblock copolymer (BP-6) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 6.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 22.0 g of 4-pentamethyldisilylstyrene and 35.0 g of styrene that had been purified by distillation was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes. Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes. Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (BP-5).

[0088] Next, 50 g of the obtained diblock copolymer (BP-5) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-6). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of the diblock copolymer (BP-6).

[0089] The composition ratio, Mn, Mw, and PDI of the obtained diblock copolymer (BP-6) were measured by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below. (4-pentamethyldisilylstyrene + styrene) (PMDSSt + St): 4-hydroxystyrene (HSt) = 48:52 Mn=9362 Mw=9736 PDI=1.04

[0090] Next, the identity period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the identity period (d) was 18.0 nm and hp was 9.0 nm. The measurement results are shown in Table 2 below.

[0091] Example 4: Synthesis of tetrablock copolymer (BP-8) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 7.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 24.0 g of 4-pentamethyldisilylstyrene and 12.0 g of styrene that had been purified by distillation was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes. Next, 45.0 g of 4-(1-ethoxyethoxy)styrene, which had been further dehydrated by distillation, was added dropwise and allowed to react for 30 minutes. A mixture of 24.0 g of 4-pentamethyldisilylstyrene and 12.0 g of styrene, which had been purified by distillation, was then added dropwise, and the reaction was allowed to continue for another 30 minutes after the dropwise addition was completed. Next, 45.0 g of 4-(1-ethoxyethoxy)styrene, which had been further dehydrated by distillation, was added dropwise and allowed to react for another 30 minutes. The polymerization reaction was then terminated by adding 30 g of methanol, and the reaction solution was concentrated to obtain 100 g of tetrablock copolymer (BP-7).

[0092] Next, 50 g of the obtained tetrablock copolymer (BP-7) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected tetrablock copolymer. The deprotected tetrablock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the tetrablock copolymer (BP-8). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of the tetrablock copolymer (BP-8).

[0093] The resulting tetrablock copolymer (BP-8) was used to measure the composition ratio, Mn, Mw, and PDI of the tetrablock copolymer (BP-8) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below. (4-pentamethyldisilylstyrene + styrene) (PMDSSt + St): 4-hydroxystyrene (HSt) = 48:52 Mn=9089 Mw=9453 PDI=1.04

[0094] Next, the uniform period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the uniform period (d) was 8.0 nm and hp was 4.0 nm. The measurement results are shown in Table 2 below.

[0095] Example 5: Synthesis of hexablock copolymer (BP-10) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 7.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 16.0 g of 4-pentamethyldisilylstyrene and 8.0 g of styrene that had been purified by distillation was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes. Next, 30.0 g of 4-(1-ethoxyethoxy)styrene, which had been further dehydrated by distillation, was added dropwise and allowed to react for 30 minutes. A mixture of 16.0 g of 4-pentamethyldisilylstyrene and 8.0 g of styrene, which had been purified by distillation, was then added dropwise, and the reaction continued for another 30 minutes after the dropwise addition. Next, 30.0 g of 4-(1-ethoxyethoxy)styrene, which had been further dehydrated by distillation, was added dropwise and allowed to react for another 30 minutes. A mixture of 16.0 g of 4-pentamethyldisilylstyrene and 8.0 g of styrene, which had been purified by distillation, was then added dropwise, and the reaction continued for another 30 minutes after the dropwise addition. Next, 30.0 g of 4-(1-ethoxyethoxy)styrene, which had been further dehydrated by distillation, was added dropwise and allowed to react for another 30 minutes. The polymerization reaction was then terminated by adding 30 g of methanol, and the reaction solution was concentrated to obtain 100 g of hexablock copolymer (BP-9).

[0096] Next, 50 g of the resulting hexablock copolymer (BP-9) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected hexablock copolymer. The deprotected hexablock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the hexablock copolymer (BP-10). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of a hexablock copolymer (BP-10).

[0097] The composition ratio, Mn, Mw, and PDI of the resulting hexablock copolymer (BP-10) were measured by the above-mentioned measurement methods. The measurement results are shown below and in Table 2. Composition ratio (molar ratio) of hexablock copolymer (BP-10) (4-pentamethyldisilylstyrene + styrene) (PMDSSt + St): 4-hydroxystyrene (HSt) = 48:52 Mn=9089 Mw=9453 PDI=1.04

[0098] Next, the identity period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the identity period (d) was 7.6 nm and hp was 3.8 nm. The measurement results are shown in Table 2 below.

[0099] Example 6: Synthesis of diblock copolymer (BP-12) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 20.0 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 48.0 g of 4-pentamethyldisilylstyrene that had been purified by distillation and 24.0 g of styrene was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition, the reaction was continued for an additional 30 minutes. Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes. Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (BP-11).

[0100] Next, 50 g of the obtained diblock copolymer (BP-11) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-12). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of a diblock copolymer (BP-12).

[0101] The composition ratio, Mn, Mw, and PDI of the diblock copolymer (BP-12) obtained were measured by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below. (4-pentamethyldisilylstyrene + styrene) (PMDSSt + St): 4-hydroxystyrene (HSt) = 48:52 Mn=3223 Mw=3352 PDI=1.04

[0102] Next, the uniform period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the uniform period (d) was 8.0 nm and hp was 4.0 nm. The measurement results are shown in Table 2 below.

[0103] Example 7: Synthesis of diblock copolymer (BP-14) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 1.35 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 48.0 g of 4-pentamethyldisilylstyrene that had been purified by distillation and 24.0 g of styrene was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition, the reaction was continued for an additional 30 minutes. Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes. Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (BP-13).

[0104] Next, 50 g of the obtained diblock copolymer (BP-13) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-14). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of a diblock copolymer (BP-14).

[0105] The composition ratio, Mn, Mw, and PDI of the diblock copolymer (BP-14) obtained were measured by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below. (4-pentamethyldisilylstyrene + styrene) (PMDSSt + St): 4-hydroxystyrene (HSt) = 48:52 Mn=46860 Mw=48735 PDI=1.04

[0106] Next, the identity period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the identity period (d) was 20.0 nm and hp was 10.0 nm. The measurement results are shown in Table 2 below.

[0107] Example 8: Synthesis of diblock copolymer (BP-16) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 6.50 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, a mixture of 24.0 g of 4-pentamethyldisilylstyrene, 24.0 g of styrene, and 24.0 g of 4-trimethylsilylstyrene that had been purified by distillation was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition, the reaction was continued for an additional 30 minutes. Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes. Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (BP-15).

[0108] Next, 50 g of the obtained diblock copolymer (BP-15) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-16). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of a diblock copolymer (BP-16).

[0109] The composition ratio, Mn, Mw, and PDI of the diblock copolymer (BP-16) obtained were measured by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below. (4-pentamethyldisilylstyrene + styrene) (PMDSSt + St): 4-hydroxystyrene (HSt) = 48:52 [4-pentamethyldisilylstyrene + styrene + 4-trimethylsilylstyrene (TMSSt)] (PMDSSt + St + TMSSt):4-hydroxystyrene (HSt) = 50:50 Mn=9783 Mw=10175 PDI=1.04

[0110] Next, the identity period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the identity period (d) was 16.0 nm and hp was 8.0 nm. The measurement results are shown in Table 2 below.

[0111] (Comparative Example 1: Synthesis of diblock copolymer (RBP-2)) A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4500 g of a tetrahydrofuran (THF) solution that had been distilled and dehydrated using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 5.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol / L) was poured into the cooled THF solution. Next, 48.9 g of styrene that had been purified by distillation was added dropwise, adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes. Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes. Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (RBP-1).

[0112] Next, 50 g of the obtained diblock copolymer (RBP-1) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40°C under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction. The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (RBP-2). Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powder solid of a diblock copolymer (RBP-2).

[0113] The resulting diblock copolymer (RBP-2) was used to measure the composition ratio, Mn, Mw, and PDI of the diblock copolymer (RBP-2) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below. Styrene (St): 4-hydroxystyrene (HSt) = 50:50 Mn=10423 Mw=10840 PDI=1.04

[0114] Next, the identity period (d) and hp of the pattern produced by the above-mentioned method were measured. As a result, the identity period (d) was 20.0 nm and hp was 10.0 nm. The measurement results are shown in Table 2 below.

[0115] (Etching rate measurement) Polymers for evaluation were prepared from the structural units of the block copolymers prepared in the Examples and Comparative Examples, and the etching rates (nm / sec) of each were measured.

[0116] The poly(4-hydroxystyrene) (PHSt) described below is a polymer having 4-hydroxystyrene (HSt) as a constituent unit. Polystyrene (PSt) is a polymer whose structural unit is styrene (St). PMDSSt-St random copolymer is a random copolymer of 4-pentamethyldisilylstyrene and styrene. The PMDSSt-St-TMSSt random copolymer is a random polymer of 4-pentamethyldisilylstyrene, styrene, and 4-trimethylsilylstyrene.

[0117] <Poly 4-hydroxystyrene (PHSt)> A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.). The flask was equipped with a Dimroth condenser, a thermometer, and a vacuum line. The pressure was reduced and the contents were purged with nitrogen three times. Subsequently, 20.5 g of 4-hydroxystyrene (HSt) and 20.0 g of toluene were added, and the reaction solution in the flask was stirred with a magnetic stirrer while bubbling nitrogen at 0°C for 15-20 minutes. The reaction solution was then heated to 70°C in an oil bath and stirred for 5 hours. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask. The resulting precipitate was collected by vacuum filtration and dried under vacuum at 60°C to obtain 15 g of poly(4-hydroxystyrene) (PHSt).

[0118] The weight average molecular weight and molecular weight distribution of the obtained poly(4-hydroxystyrene) (PHSt) were measured in the same manner as in Example 1. The measurement results are as follows. Mw:100000 ·Molecular weight distribution (Mw / Mn)=1.90

[0119] <Polystyrene (PSt)> A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.). The flask was equipped with a Dimroth condenser, a thermometer, and a vacuum line. The pressure was reduced and the contents were purged with nitrogen three times. Subsequently, 20.5 g of styrene (St) and 20.0 g of toluene were added, and the reaction solution in the flask was stirred with a magnetic stirrer while bubbling nitrogen at 0°C for 15-20 minutes. The reaction solution was then heated to 70°C in an oil bath and stirred for 5 hours. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask. The precipitate was collected by vacuum filtration and dried under vacuum at 60°C to obtain 15 g of polystyrene (PSt).

[0120] The weight average molecular weight and molecular weight distribution of the obtained polystyrene (PSt) were measured in the same manner as in Example 1. The measurement results are as follows. Mw:100000 ·Molecular weight distribution (Mw / Mn)=1.90

[0121] <PMDSSt-Stランダムコポリマー(1)> A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.). The flask was equipped with a Dimroth condenser, a thermometer, and a vacuum line. The pressure was reduced and the contents were purged with nitrogen three times. Next, 13.6 g of 4-pentamethyldisilylstyrene (PMDSSt), 6.9 g of styrene, and 20.0 g of toluene were added. The reaction solution in the flask was stirred with a magnetic stirrer at 0°C for 15-20 minutes while bubbling with nitrogen. The reaction solution was then heated to 70°C in an oil bath and stirred for 5 hours. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask. The resulting precipitate was collected by vacuum filtration and dried under vacuum at 60°C to obtain 15 g of PMDSSt-St random copolymer (1).

[0122] The weight average molecular weight and molecular weight distribution of the obtained PMDSSt-St random copolymer (1) were measured in the same manner as in Example 1. The measurement results are as follows. Mw=100000 ·Molecular weight distribution (Mw / Mn)=1.90 Composition ratio (molar ratio): PMDSSt / St = 47 / 53

[0123] <PMDSSt-Stランダムコポリマー(2)> A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.). The flask was equipped with a Dimroth condenser, a thermometer, and a vacuum line. The pressure was reduced and the contents were purged with nitrogen three times. Next, 19.4 g of 4-pentamethyldisilylstyrene (PMDSSt), 1.1 g of styrene, and 20.0 g of toluene were added. The reaction solution in the flask was stirred with a magnetic stirrer while bubbling with nitrogen at 0°C for 15-20 minutes. The reaction solution was then heated to 70°C in an oil bath and stirred for 5 hours. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask. The resulting precipitate was collected by vacuum filtration and dried under vacuum at 60°C to obtain 15 g of PMDSSt-St random copolymer (2).

[0124] The weight average molecular weight and molecular weight distribution of the obtained PMDSSt-St random copolymer (2) were measured in the same manner as in Example 1. The measurement results are as follows. Mw:100000 ·Molecular weight distribution (Mw / Mn)=1.90 Composition ratio (molar ratio): PMDSSt / St = 89 / 11

[0125] <PMDSSt-Stランダムコポリマー(3)> A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.). The flask was equipped with a Dimroth condenser, a thermometer, and a vacuum line. The pressure was reduced and the contents were purged with nitrogen three times. Subsequently, 7.9 g of 4-pentamethyldisilylstyrene (PMDSSt), 12.6 g of styrene, and 20.0 g of toluene were added. The reaction solution in the flask was stirred with a magnetic stirrer while bubbling with nitrogen at 0°C for 15-20 minutes. The reaction solution was then heated to 70°C in an oil bath and stirred for 5 hours. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask. The resulting precipitate was collected by vacuum filtration and dried under vacuum at 60°C to obtain 15 g of PMDSSt-St random copolymer (3).

[0126] The weight average molecular weight and molecular weight distribution of the obtained PMDSSt-St random copolymer (3) were measured in the same manner as in Example 1. The measurement results are as follows. Mw:100000 ·Molecular weight distribution (Mw / Mn)=1.90 Composition ratio (molar ratio): PMDSSt / St=22 / 78

[0127] <PMDSSt-St-TMSStランダムコポリマー> A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.). The flask was equipped with a Dimroth condenser, a thermometer, and a vacuum line. The pressure was reduced and the flask was purged with nitrogen three times. Next, 6.8 g of 4-pentamethyldisilylstyrene (PMDSSt), 6.8 g of styrene, 6.9 g of 4-trimethylsilylstyrene (TMSSt), and 20.0 g of toluene were added. The reaction solution in the flask was stirred with a magnetic stirrer at 0 °C for 15–20 minutes while bubbling with nitrogen. The reaction solution was then heated to 70 °C in an oil bath and stirred for 5 hours. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask, and the resulting precipitate was collected by filtration under reduced pressure and dried in vacuo at 60°C to obtain 15 g of a PMDSSt-St-TMSSt random copolymer.

[0128] The weight average molecular weight and molecular weight distribution of the obtained PMDSSt-St-TMSSt random copolymer were measured in the same manner as in Example 1. The measurement results are as follows. Mw:100000 ·Molecular weight distribution (Mw / Mn)=1.90 Composition ratio (molar ratio): PMDSSt / St / TMSSt = 22 / 49 / 29

[0129] Each solution was prepared by dissolving 1 g of each polymer for evaluation in 99 g of propylene glycol monomethyl ether acetate. The resulting solution was applied to a silicon wafer using a spin coater (MIKASA, SPINCOATER 1H-360S). The coating was heated at 120°C for 60 seconds to form a polymer layer (approximately 600 nm thick) for use as a sample for etching rate measurement. After irradiating the polymer layer with electron beams (EB), dry plasma etching was performed using 100 W, 50 sccm oxygen plasma. The etching equipment used was a batch-type plasma cleaner PX-250 manufactured by March Plasma Systems. The thickness of the polymer layer before and after etching was measured and compared using a Filmetrics F20 to determine the etching rate (nm / sec). The ratio of the etching rate of each polymer layer to the etching rate of the poly(4-hydroxystyrene) (PHSt) film was calculated as the etching rate ratio. The smaller the etching rate ratio, the higher the selectivity of poly(4-hydroxystyrene) (PHSt), which corresponds to the second polymer block of the block copolymer, to be removed by etching.

[0130] [Table 1]

[0131] As shown in Table 1, the PMDSSt-St random copolymer (1), PMDSSt-St random copolymer (2), PMDSSt-St random copolymer (3), and PMDSSt-St-TMSSt random copolymer showed smaller etching rate ratios compared to PSt. These results confirmed that domains mainly containing the second polymer block can be removed with high selectivity from the lamellar structures formed by phase separation of the block copolymers of Examples 1 to 8, which have a first polymer block corresponding to PMDSSt-St random copolymer (1), PMDSSt-St random copolymer (2), PMDSSt-St random copolymer (3), and PMDSSt-St-TMSSt random copolymer and a second polymer block corresponding to PHSt. The first polymer block of the copolymers prepared in Examples 1 and 4 to 7 corresponds to the TMSSt-BSt random copolymer (1), the first polymer block of the copolymer prepared in Example 2 corresponds to the TMSSt-BSt random copolymer (2), and the first polymer block of the copolymer prepared in Example 3 corresponds to the TMSSt-BSt random copolymer (3). The first polymer block of the copolymer prepared in Example 8 corresponds to a PMDSSt-St-TMSSt random copolymer, and the first polymer block of the copolymer prepared in Comparative Example 1 corresponds to PSt.

[0132] <Etching resistance evaluation results> For the Examples and Comparative Examples, the ratio of the etching rate of the polymer for evaluation corresponding to the first polymer block to the etching rate of PHSt (corresponding to the second polymer block of each block copolymer) was calculated as the rate ratio, and evaluated according to the following criteria. For example, in the case of Example 1, the ratio of the etching rate of the PMDSSt-St random copolymer (1) to the etching rate of PHSt was calculated as the rate ratio, and the rate ratio was found to be 0.06. The results are shown in Table 2. ◯: The etching rate ratio was 0.20 or less. ×: The etching rate ratio exceeded 0.20.

[0133] <Half pitch (hp) evaluation results> The half pitch (hp) of the self-assembled monolayer measured in the examples and comparative examples was evaluated according to the following criteria. The results are shown in Table 2. ◯: The half pitch (hp) of the self-assembled monolayer was 10.0 nm or less. ×: The half pitch (hp) of the self-assembled monolayer exceeded 10.0 nm.

[0134] [Table 2]

[0135] From Table 2, it was confirmed that in Examples 1 to 8, the half pitch (hp) was sufficiently small and the PDI was small, so that a uniform self-assembled film could be formed, and that the etching resistance was also excellent.

Claims

1. a first polymer block that is a random copolymer containing a constitutional unit represented by the following general formula (1) and a constitutional unit represented by the following general formula (3); and a second polymer block containing a constitutional unit represented by the following general formula (4), the first polymer block contains 10 to 80 mol % of the constitutional unit represented by general formula (3) relative to the entire first polymer block, The multiblock copolymer is a polymer material having a number average molecular weight of 3,000 or more and 50,000 or less. 【Chemistry 1】 [In general formula (1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, a is an integer of 1 or more and 1000 or less, and X is a substituent represented by general formula (2). 【Chemistry 2】 [In general formula (2), b is an integer of 2 or more and 8 or less.] 【Transformation 3】 [In general formula (3), R ２ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and c is an integer of 1 to 1,000. 【Chemistry 4】 [In general formula (4), R ３ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and d is an integer of 1 to 1000.

2. The polymer material according to claim 1 , wherein the first polymer block is a polymer represented by the general formula (2), in which b is 2.

3. The polymer material according to claim 1 or 2, wherein the first polymer block further comprises a structural unit represented by the following general formula (5): 【Transformation 5】 [In general formula (5), R ４ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and e is an integer of 1 to 1000.

4. 3. The polymer material according to claim 1, wherein the multiblock copolymer is a diblock copolymer or more and a hexablock copolymer or less.

5. 3. The polymer material according to claim 1, wherein the multiblock copolymer is copolymerized by living anionic polymerization.

6. A self-assembled film obtained by using the polymer material according to claim 1 or 2.

7. The self-assembled film according to claim 6, wherein the surface is coated with a top coating agent.

8. A method for producing a self-assembled film, comprising forming a self-assembled film using the polymer material according to claim 1 or 2.

9. The method for producing a self-assembled film according to claim 8, wherein the self-assembled film is formed within the guide pattern.

10. The method for producing a self-assembled film according to claim 8 , further comprising the step of applying a top coating agent onto the self-assembled film.

11. A pattern obtained by etching the self-assembled film according to claim 6.

12. A method for forming a pattern, comprising the step of etching the self-assembled film according to claim 6 to form a pattern.

Images