Base material and method for producing structure containing phase-separated structure

Abstract

To provide a base material capable of forming a phase separation structure excellent in horizontal orientation, and a method for manufacturing a structure including the phase separation structure.SOLUTION: A base material used for phase-separating a layer containing a block copolymer, the base material containing a block copolymer (A) having a block (a1) having a constitutional unit represented by Formula (a1) and a block (A2) having a constitutional unit represented by Formula (A2), in which a proportion of the number of moles of the constitutional unit constituting the block (A2) is more than 0% by mole and 40% by mole or less. In Formula (a1), Ra11 is hydrogen or the like, Ra12 is a substitution group, n is an integer of 0 or more and 5 or less, in Formula (a2), Ra21 is hydrogen or the like, L1 is a single-bond or the like, and Y1 is a divalent linking group having a carbon number of 1 or more and 15 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a substrate and a structure containing a phase-separated structure. [Background technology]

[0002] In recent years, with the further miniaturization of large-scale integrated circuits (LSIs), there has been a demand for technologies to fabricate ever more delicate structures. In response to this demand, technological development is being conducted to fabricate ever more delicate structures by utilizing the phase-separated structures formed by the self-assembly of block copolymers, in which mutually incompatible blocks are bonded. To utilize the phase-separated structure of block copolymers, it is essential to form the self-assembled nanostructures formed by microphase separation only in specific regions and align them in the desired direction. To achieve this positional and orientation control, processes such as graphoepitaxy, which uses guide patterns to control the phase separation pattern, and chemical epitaxy, which controls the phase separation pattern by changing the chemical state of the substrate, have been proposed.

[0003] As a method for forming a fine pattern by phase separation of a block copolymer, for example, a method of forming an underlayer on a substrate has been disclosed. For example, Patent Document 1 discloses an underlayer containing a copolymer in which structural units derived from styrene and structural units derived from hydroxyethyl acrylate are randomly arranged. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6475963 Summary of the Invention [Problem to be solved by the invention]

[0005] When a polymer primarily containing structural units derived from styrene or its derivatives is used as an underlayer, it is ideal for the phase-separated structure formed by the block copolymer to be oriented horizontally relative to the surface of the substrate. However, with conventional underlayers such as those disclosed in Patent Document 1, when a block copolymer with a large structural period (L0) is used for phase separation, there is a problem in that vertically oriented phase-separated structures are mixed in.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a base material capable of forming a phase-separated structure with excellent horizontal alignment, and a method for manufacturing a structure including a phase-separated structure. [Means for solving the problem]

[0007] In order to solve the above problems, the present inventors have conducted extensive research and have found that the above problems can be solved by using a base material containing a specific block polymer (A), thereby completing the present invention. Specifically, the present invention provides the following.

[0008] A first aspect of the present invention is a base material used to phase separate a layer containing a block copolymer, comprising: Contains a block copolymer (A), The block copolymer (A) has a block (A1) and a block (A2), The block (A1) has a structural unit represented by the following formula (a1): The block (A2) has a structural unit represented by the following formula (a2): the block copolymer (A) does not have a structural unit derived from a (meth)acrylic acid alkyl ester, The ratio of the number of moles of the structural units constituting the block (A2) to the total number of moles of the structural units constituting the block (A1) and the number of moles of the structural units constituting the block (A2) is more than 0 mol % and not more than 40 mol %.

[0009] A second aspect of the present invention is a method for forming a base material layer by applying the base material of the first aspect onto a substrate; forming a layer containing the block copolymer on the underlayer; and phase-separating the layer containing the block copolymer. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a base material capable of forming a phase-separated structure with excellent horizontal alignment, and a method for producing a structure including a phase-separated structure. [Brief explanation of the drawings]

[0011] [Figure 1] 1A to 1C are schematic process diagrams illustrating one embodiment of a method for producing a structure containing a phase-separated structure. [Figure 2] FIG. 10 is a diagram illustrating an embodiment of an optional step. [Figure 3] 1A and 1B are diagrams schematically illustrating an example of a structure including a phase-separated structure manufactured by a method for manufacturing a structure including a phase-separated structure according to one embodiment. [Figure 4] 1 is an example of an SEM aerial photograph of a structure including a phase-separated structure manufactured by a manufacturing method of a structure including a phase-separated structure according to one embodiment. [Figure 5] 1A to 1C are diagrams showing examples corresponding to each evaluation criterion for horizontal alignment in Examples. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments and can be practiced with appropriate modifications within the scope of the object of the present invention.

[0013] <Base material> The composition is used to phase-separate a layer containing a block copolymer and contains a block copolymer (A). The block copolymer (A) has a block (A1) and a block (A2), and does not contain a structural unit derived from a (meth)acrylic acid alkyl ester. The block (A1) has a structural unit represented by the following formula (a1). The block (A2) has a structural unit represented by the following formula (a2). The proportion of the number of moles of the structural units constituting the block (A2) to the total number of moles of the structural units constituting the block (A1) and the number of moles of the structural units constituting the block (A2) is more than 0 mol% and not more than 40 mol%. [ka] (In formula (a1), R a11 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R a12 is a substituent, and n is an integer of 0 or more and 5 or less. In formula (a2), R a21 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L 1 is a single bond or a divalent linking group, and Y 1 is a divalent linking group having 1 to 15 carbon atoms.

[0014] By using such a base material, a phase-separated structure with excellent horizontal alignment can be formed. The reason why this effect is obtained is not entirely clear, but is presumed to be as follows. Polymers used in undercoats often adhere to the substrate via polar groups such as hydroxyl groups. While conventional polymers have polar groups at the end of their main chains, the number of polar groups is small, resulting in insufficient adhesion to the substrate. As a result, the density of the polymer brushes is low, making it difficult to achieve good horizontal alignment. Furthermore, conventional polymers include random copolymers in which structural units containing polar groups are randomly arranged with other structural units. However, polar groups may appear on the surface of the undercoat layer, or polar groups other than those at the end of the polymer may adhere to the substrate, inhibiting the formation of polymer brushes and adversely affecting horizontal alignment. In contrast, the block copolymer (A) used in the undercoat material of the first embodiment has a hydroxyl group-containing structural unit blocked, which provides good adhesion to the substrate. Therefore, when the block copolymer (A) is used, the density of the polymer brushes in the undercoat material of the first embodiment is high. This is thought to result in improved horizontal alignment.

[0015] <Block copolymer (A)> The block copolymer (A) has a block (A1) and a block (A2), and does not have any structural units derived from an alkyl (meth)acrylate.

[0016] The block copolymer (A) may have blocks other than the block (A1) and the block (A2) (other blocks), but preferably does not have any other blocks. When the block copolymer (A) has other blocks, it is preferable that the block (A2) is not sandwiched between blocks other than the block (A2) (that is, it is located at either end of the main chain of the block copolymer (A)).

[0017] Block (A1) The block (A1) has a structural unit represented by the following formula (a1). [ka] (In formula (a1), R a11is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R a12 is a substituent, and n is an integer of 0 to 5.

[0018] R a11 Examples of the alkyl group having 1 to 5 carbon atoms as the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, and a tert-pentyl group. A halogenated alkyl group having from 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of an alkyl group having from 1 to 5 carbon atoms have been substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atoms.

[0019] R a12 Examples of the substituent as include an optionally substituted hydrocarbon group and a halogen atom. R a12 Examples of the hydrocarbon group which may have a substituent include an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, and an aryl group which may have a substituent. Among these, an alkyl group which may have a substituent is preferred. R a12 The number of carbon atoms in the alkyl group which may have a substituent as R is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, and even more preferably 1 or more and 3 or less. a12 The substituent that the alkyl group may have is preferably an alkyl group that may be interrupted by an oxygen atom and that may be substituted with an alkylsilyl group, specifically, an alkyl group, an alkylsilyl group, an alkylsilylalkyl group, an alkylsilyloxy group, an alkylsilyloxyalkyl group, an alkoxy group, etc.

[0020] R a12Examples of the alkyl group as the aryl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group.

[0021] R a12 The alkylsilyl group as the alkyl group is preferably a trialkylsilyl group, and specific examples thereof include a trimethylsilyl group. R a12 The alkylsilylalkyl group as the alkylsilyl group is preferably a trialkylsilylalkyl group, specifically, a trimethylsilylmethyl group, a 2-trimethylsilylethyl group, a 3-trimethylsilyl-n-propyl group, etc. R a12 The alkylsilyloxy group as the alkylsilyloxy group is preferably a trialkylsilyloxy group, and specific examples thereof include a trimethylsilyloxy group. R a12 The alkylsilyloxyalkyl group as the alkylsilyloxyalkyl group is preferably a trialkylsilyloxyalkyl group, specifically, a trimethylsilyloxymethyl group, a 2-trimethylsilyloxyethyl group, a 3-trimethylsilyloxy-n-propyl group, and the like. R a12 Examples of the alkoxy group as the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, and a tert-butoxy group.

[0022] n is preferably an integer of 0 or more and 3 or less, and 0 or 1 is preferred.

[0023] Specific examples of the structural unit represented by formula (a1) are shown below. a13 is a hydrogen atom, a methyl group, or a trifluoromethyl group. [ka]

[0024] [ka]

[0025] The ratio of the number of moles of the structural units constituting block (A1) to the number of moles of all structural units constituting block copolymer (A) is preferably 60 mol% or more, more preferably 65 mol% or more, and even more preferably 70 mol% or more. Furthermore, this ratio is preferably 99 mol% or less, more preferably 97 mol% or less. Within this range, good horizontal alignment is likely to be achieved.

[0026] Block (A2) The block (A2) has a constitutional unit represented by the following formula (a2). [ka] (In formula (a2), R a21 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L 1 is a single bond or a divalent linking group, and Y 1 is a divalent linking group having 1 to 15 carbon atoms.

[0027] R a21 The alkyl group having 1 to 5 carbon atoms and the halogenated alkyl group having 1 to 5 carbon atoms as R a11 These groups are similar to those shown below.

[0028] L 1 The divalent linking group as is preferably a divalent linking group containing a heteroatom, such as an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom.

[0029] Examples of the divalent linking group containing a hetero atom include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NR-, -NR-, -NR-C(=NR)-, -S-, -S(=O)2-, -S(=O)2-O-, -L 11 -O-, -L 11 -OL 11 -, -L11 -C(=O)-O-, -C(=O)-OL 11 -, -L 11 -C(=O)-OL 11 - and -L 11 -S(=O)2-OL 11 - (wherein, each R is independently a hydrogen atom or a substituent (e.g., an alkyl group, an acyl group, etc.)). 11 are each independently a chain aliphatic hydrocarbon group. In this specification, unless otherwise specified, the bonding direction of the divalent group is not particularly limited.

[0030] The alkyl group and acyl group represented by R preferably have 1 or more and 10 or less carbon atoms, and more preferably have 1 or more and 5 or less carbon atoms.

[0031] L 11 The chain aliphatic hydrocarbon group may be saturated or unsaturated, but is preferably saturated. Also, it may be linear or branched, but is preferably linear. L 11 The chain aliphatic hydrocarbon group as is preferably a linear alkylene group, more preferably a linear alkylene group having 1 to 5 carbon atoms, further preferably a methylene group or ethylene group, and particularly preferably a methylene group.

[0032] L 1 is preferably a single bond, -O-, or -C(=O)-O-, and more preferably a single bond or -C(=O)-O-.

[0033] Y 1 Examples of the divalent linking group include divalent hydrocarbon groups having 1 to 15 carbon atoms which may have a substituent.

[0034] Y 1 The optionally substituted divalent hydrocarbon group preferably has 1 or more and 12 or less carbon atoms.

[0035] Y 1The hydrocarbon group as may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination of an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

[0036] Y 1 The aliphatic hydrocarbon group as may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group, but is preferably a saturated aliphatic hydrocarbon group. Y 1 The aliphatic hydrocarbon group as Y may be a chain aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or a combination of a chain aliphatic hydrocarbon group and an alicyclic hydrocarbon group. 1 The chain aliphatic hydrocarbon group contained in the aliphatic hydrocarbon group as Y may be linear or branched. 1 The chain aliphatic hydrocarbon group contained in the aliphatic hydrocarbon group as defined above is preferably an alkylene group.

[0037] The alkylene group preferably has 1 or more and 10 or less carbon atoms, more preferably 1 or more and 8 or less carbon atoms, and even more preferably 1 or more and 5 or less carbon atoms. Examples of the linear alkylene group include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. Examples of branched alkylene groups include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0038] The chain aliphatic hydrocarbon group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxy group. Among these, a hydroxy group is preferred. In the chain aliphatic hydrocarbon group, at least a portion of the methylene groups may be substituted with a divalent group other than methylene groups. Examples of the divalent group include -O-, -S-, and -C(=O)-. Of these, -O- is preferred.

[0039] The alicyclic hydrocarbon group preferably has 3 or more and 20 or less carbon atoms, more preferably 3 or more and 12 or less carbon atoms, and even more preferably 5 or more and 12 or less carbon atoms. The alicyclic hydrocarbon group may be a monocyclic group or a polycyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 or more and 6 or less carbon atoms. Specific examples of monocycloalkanes include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane. The polycycloalkane preferably has 7 or more and 12 or less carbon atoms. Specific examples of polycycloalkanes include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0040] The alicyclic hydrocarbon group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxy group. Among these, a hydroxy group is preferred. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having from 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, or a tert-butyloxy group, and still more preferably a methoxy group or an ethoxy group. The halogen atom as the substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl groups mentioned above have been substituted with the halogen atoms mentioned above. In the alicyclic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a group containing a heteroatom, preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-, and more preferably -O-.

[0041] Y 1The aromatic hydrocarbon group may be a monocyclic aromatic hydrocarbon group or a polycyclic aromatic hydrocarbon group. The polycyclic aromatic hydrocarbon group may be a group in which two or more aromatic rings are fused to a monocyclic aromatic hydrocarbon group, or may be a group in which one or more aromatic hydrocarbon groups are bonded via a single bond to a monocyclic aromatic hydrocarbon group or a group in which two or more aromatic rings are fused to a monocyclic aromatic hydrocarbon group. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 30, more preferably 6 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Examples of aromatic rings constituting the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, a biphenyl ring, an anthracene ring, and a phenanthrene ring. Among these, a benzene ring and a naphthalene ring are preferred, and a benzene ring is more preferred.

[0042] The aromatic hydrocarbon group may have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, or a hydroxy group. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent that the aromatic hydrocarbon group may have are the same as the substituent that the above-mentioned alicyclic hydrocarbon group may have.

[0043] Y 1 As the alkylene group, a chain aliphatic hydrocarbon group which may have a substituent, an alicyclic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a combination thereof is preferred, an alkylene group which may have a substituent, an alicyclic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a combination thereof is more preferred, and an alkylene group which may have a hydroxy group and in which at least a portion of the methylene groups may be substituted with -O-, an alicyclic hydrocarbon group which may have a hydroxy group and in which a portion of the carbon atoms constituting the ring structure may be substituted with -O-, an aromatic hydrocarbon group, or a combination thereof is even more preferred.

[0044] Specific examples of the structural unit represented by formula (a2) are shown below.a22 is a hydrogen atom, a methyl group, or a trifluoromethyl group. [ka]

[0045] [ka]

[0046] The ratio of the number of moles of the structural units constituting block (A2) to the total number of moles of the structural units constituting block (A1) and the number of moles of the structural units constituting block (A2) is preferably 1 mol% or more, more preferably 3 mol% or more. Furthermore, this ratio is preferably 35 mol% or less, more preferably 30 mol% or less. Within this range, good horizontal alignment is likely to be achieved.

[0047] The ratio of the number of moles of the structural units constituting block (A2) to the number of moles of all structural units constituting block copolymer (A) is preferably 1 mol% or more, more preferably 3 mol% or more. Furthermore, this ratio is preferably 35 mol% or less, more preferably 30 mol% or less. Within this range, good horizontal alignment is likely to be achieved.

[0048] The sum of the number of moles of the structural units constituting the block (A1) and the number of moles of the structural units constituting the block (A2) relative to the number of moles of all structural units constituting the block copolymer (A) is preferably 70 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and may be 100 mol %.

[0049] The number average molecular weight (Mn) of the block copolymer (A) is preferably 500 or more, more preferably 1,000 or more. Furthermore, the Mn is preferably 30,000 or less, more preferably 20,000 or less, and even more preferably 10,000 or less. When the Mn is within the above numerical range, good horizontal alignment is likely to be obtained. The molecular weight dispersity (Mw / Mn) of the block copolymer (A) is preferably 1.0 or more and 3.0 or less, more preferably 1.0 or more and 1.5 or less, and even more preferably 1.0 or more and 1.3 or less, where Mw represents the mass average molecular weight. In this specification, the "number average molecular weight" (Mn) and "weight average molecular weight" (Mw) are the number average molecular weight and weight average molecular weight calculated in terms of standard polystyrene by gel permeation chromatography (GPC) measurement.

[0050] The method for producing the block copolymer (A) is not particularly limited. For example, it can be produced by polymerizing a monomer of the structural unit constituting the block (A1) and a monomer of the structural unit constituting the block (A2) by a conventionally known polymerization method. During polymerization, a monomer in which a hydroxy group is protected with a conventionally known protecting group such as a trimethylsilyl group or an acetal structure may be used as the monomer of the structural unit constituting the block (A2). In this case, deprotection is carried out after polymerization.

[0051] The content of the block copolymer (A) is preferably 70% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, relative to 100% by mass of the solid content of the base material, and may be 100% by mass.

[0052] <Solvent (S)> The base material may contain a solvent (S). The solvent (S) may be an organic solvent. The organic solvent may be any organic solvent capable of dissolving each component to be used and forming a homogeneous solution. Any organic solvent selected from organic solvents conventionally known as solvents for compositions containing a resin as a main component may be used.

[0053] Examples of organic solvents include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; monoacetates of polyhydric alcohols such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; and compounds of polyhydric alcohols having an ether bond such as monoalkyl ethers, monomethyl ethers, monoethyl ethers, monopropyl ethers, and monobutyl ethers of the polyhydric alcohols or monoacetates of the polyhydric alcohols, or monophenyl ethers. Derivatives [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane; monoacetates of polyhydric alcohols such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; and esters other than the derivatives of the aforementioned polyhydric alcohols; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene. The organic solvent components may be used alone or in a mixture of two or more. Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, or ethyl lactate (EL) is preferred.

[0054] The content of the solvent contained in the base material is not particularly limited. The solvent is appropriately selected depending on the coating film thickness so that the concentration of the base material is a concentration that can be applied. The solvent is generally used so that the solid content concentration of the base material is in the range of 0.2% by mass to 70% by mass, preferably 0.2% by mass to 50% by mass.

[0055] <Other ingredients> Optionally, the primer may further contain compatible additives, such as additional resins to improve the performance of the primer layer, surfactants to improve coatability, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, sensitizers, base amplifiers, and basic compounds.

[0056] (Water contact angle on the surface of the undercoat layer formed on the substrate) The base material is formed on a substrate and baked at 160°C, and the water contact angle (hereinafter also referred to as "contact angle (160°C)") on the surface of the base material layer formed is preferably 80° or more, and more preferably 85° or more. The base material is formed on a substrate and baked at 240°C, and the water contact angle (hereinafter also referred to as "contact angle (240°C)") on the surface of the base material layer is preferably 80° or more, more preferably 85° or more, and even more preferably 88° or more. The difference between the contact angle (240°C) and the contact angle (160°C) of the base material (contact angle (240°C) - contact angle (160°C)) is preferably 5.0° or less, and more preferably 3.0° or less.

[0057] When the contact angle is within the above range, it is believed that the adhesion between the substrate and the layer containing the block copolymer via the underlayer is strengthened. Accordingly, it is believed that the phase separation performance of the layer containing the block copolymer formed on the underlayer is improved. Furthermore, when the contact angle (160°C) is within the above range, it is believed that sufficient phase separation performance can be obtained even when baking at a temperature of 200°C or less (e.g., 160°C or higher and 200°C or lower).

[0058] The water contact angle is measured, for example, by the following procedure, more specifically, by the procedure described in the Examples below. Step (1): A PGMEA solution of the block copolymer (A) is applied onto a substrate and baked at 160° C. or 240° C. for 120 seconds to form an undercoat layer with a thickness of 25 nm. Step (2): Rinse the primer layer to remove any polymer that is not in contact with the substrate. Step (3): 2 μL of water is dropped onto the surface of the base material layer, and the contact angle (static contact angle) is measured using a contact angle meter.

[0059] <Method for producing structure including phase-separated structure> A method for producing a structure containing a phase-separated structure includes applying a first embodiment of a base material to form a base material layer (hereinafter also referred to as "step (i)"), forming a layer containing a block copolymer on the base material layer (hereinafter also referred to as "step (ii)"), and phase-separating the layer containing the block copolymer (hereinafter also referred to as "step (iii)"). Hereinafter, a method for producing such a structure containing a phase-separated structure will be specifically described with reference to Fig. 1. However, the present invention is not limited to this.

[0060] FIG. 1 shows an embodiment of a method for producing a structure containing a phase-separated structure. First, an undercoat material is applied onto a substrate 1 to form an undercoat layer 2 (FIG. 1(I); step (i)). Next, a composition containing a block copolymer (hereinafter also referred to as "BCP composition") is applied onto the base material layer 2 to form a layer 3 containing the block copolymer (Figure 1(II); step (ii)). Next, an annealing treatment is performed by heating, causing the layer 3 containing the block copolymer to separate into a phase 3a and a phase 3b (FIG. 1(III); step (iii)). According to the manufacturing method of the present embodiment described above, that is, the manufacturing method including steps (i) to (iii), a structure 3' including a phase-separated structure is manufactured on the substrate 1 on which the undercoat layer 2 is formed.

[0061] [Block copolymer] The block copolymer is, for example, a polymer compound in which a hydrophobic polymer block (b11) and a hydrophilic polymer block (b21) are bonded together. The hydrophobic polymer block (b11) (hereinafter simply referred to as "block (b11)") is a block consisting of a polymer (hydrophobic polymer) formed by the polymerization of a monomer having a relatively low affinity for water. The hydrophilic polymer block (b21) (hereinafter simply referred to as "block (b21)") is a block consisting of a polymer (hydrophilic polymer) formed by the polymerization of a monomer having a relatively high affinity for water.

[0062] The block (b11) and the block (b21) are not particularly limited as long as they are a combination that causes phase separation, but a combination of blocks that are incompatible with each other is preferred. Furthermore, the block (b11) and the block (b21) are preferably a combination in which a phase consisting of at least one type of block among the multiple types of blocks constituting the block copolymer can be more easily removed than phases consisting of other types of blocks. The number of types of blocks constituting the block copolymer may be two or more. The block copolymer may have partial constituent components (blocks) other than the block (b11) and the block (b21) bonded thereto.

[0063] Examples of block (b11) and block (b21) include a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded together, a block in which structural units derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent (structural units derived from an (α-substituted) acrylate ester) are repeatedly bonded together, a block in which structural units derived from acrylic acid in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent (structural units derived from (α-substituted) acrylic acid) are repeatedly bonded together, a block in which structural units derived from siloxane or a derivative thereof are repeatedly bonded together, a block in which structural units derived from alkylene oxide are repeatedly bonded together, and a block in which structural units containing a silsesquioxane structure are repeatedly bonded together.

[0064] Examples of styrene derivatives include compounds in which the hydrogen atom bonded to the carbon atom at the α-position of styrene is substituted with a substituent such as an alkyl group having from 1 to 10 carbon atoms, and compounds in which the hydrogen atom of the phenyl group of styrene is substituted with a substituent such as an alkyl group having from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10 carbon atoms, a hydroxy group, a nitro group, a halogen atom, or an acetoxy group. Specific examples of styrene derivatives include α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-tert-butylstyrene, 4-n-octylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-tert-butoxystyrene, 4-hydroxystyrene, 4-nitrostyrene, 3-nitrostyrene, 4-chlorostyrene, 4-fluorostyrene, 4-acetoxystyrene, and 4-chloromethylstyrene.

[0065] The (α-substituted) acrylic ester is an acrylic ester or an acrylic acid derivative in which the hydrogen atom bonded to the carbon atom at the α-position of the acrylic ester is substituted with a substituent. Examples of the substituent in the (α-substituted) acrylic acid ester include an alkyl group having from 1 to 5 carbon atoms and a halogenated alkyl group having from 1 to 5 carbon atoms. Among these, an alkyl group having from 1 to 5 carbon atoms is preferred, and a methyl group is more preferred.

[0066] Suitable examples of the (α-substituted) acrylic acid ester include (α-substituted) alkyl acrylates, (α-substituted) cycloalkyl acrylates, (α-substituted) hydroxyalkyl acrylates, (α-substituted) aryl acrylates, (α-substituted) aralkyl acrylates, (α-substituted) epoxyalkyl acrylates, and (α-substituted) epoxycycloalkylalkyl acrylates. Among these (α-substituted) acrylic acid esters, (α-substituted) alkyl acrylate esters are preferred. In the (α-substituted) alkyl acrylate esters, the alkyl group constituting the alkyl ester preferably has 1 or more and 10 or less carbon atoms, more preferably 1 or more and 5 or less carbon atoms. Specific examples of the (α-substituted) acrylic acid ester include acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, octyl acrylate, nonyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, benzyl acrylate, anthryl acrylate, glycidyl acrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3-trimethoxysilylpropyl acrylate; and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, nonyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, benzyl methacrylate, anthryl methacrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, and 3-trimethoxysilylpropyl methacrylate.

[0067] Of the above, the (α-substituted) acrylic acid ester is preferably an alkyl acrylate or an alkyl methacrylate, more preferably methyl acrylate, ethyl acrylate, tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, or tert-butyl methacrylate, and even more preferably methyl methacrylate.

[0068] Examples of the (α-substituted) acrylic acid include acrylic acid and acrylic acid in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. Specific examples of the (α-substituted) acrylic acid include acrylic acid and methacrylic acid.

[0069] Examples of siloxane or its derivatives include dimethylsiloxane, diethylsiloxane, diphenylsiloxane, and methylphenylsiloxane. Examples of the alkylene oxide include ethylene oxide, propylene oxide, isopropylene oxide, and butylene oxide. The silsesquioxane structure-containing structural unit is preferably a cage silsesquioxane structure-containing structural unit. Examples of monomers that provide the cage silsesquioxane structure-containing structural unit include compounds having a cage silsesquioxane structure and a polymerizable group.

[0070] Examples of block copolymers include polymeric compounds comprising a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded to a block in which structural units derived from an (α-substituted) acrylic acid ester are repeatedly bonded; polymeric compounds comprising a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded to a block in which structural units derived from an (α-substituted) acrylic acid ester are repeatedly bonded; polymeric compounds comprising a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded to a block in which structural units derived from a siloxane or a derivative thereof are repeatedly bonded; and polymeric compounds comprising a block in which structural units derived from an alkylene oxide are repeatedly bonded to a block in which structural units derived from an (α-substituted) acrylic acid ester are repeatedly bonded to a block. a polymer compound in which a block in which structural units derived from an alkylene oxide are repeatedly bonded to a block in which structural units derived from (α-substituted) acrylic acid are repeatedly bonded to a polymer compound in which a block in which structural units derived from a cage silsesquioxane structure are repeatedly bonded to a block in which structural units derived from an (α-substituted) acrylic acid ester are repeatedly bonded to a polymer compound in which a block in which structural units derived from a cage silsesquioxane structure are repeatedly bonded to a block in which structural units derived from (α-substituted) acrylic acid are repeatedly bonded to a polymer compound in which a block in which structural units derived from a cage silsesquioxane structure are repeatedly bonded to a block in which structural units derived from an (α-substituted) acrylic acid are repeatedly bonded to a polymer compound in which a block in which structural units derived from a cage silsesquioxane structure are repeatedly bonded to a block in which structural units derived from a siloxane or a derivative thereof ...

[0071] Among the above, preferred block copolymers are polymeric compounds in which a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded together and a block in which structural units derived from an (α-substituted) acrylic acid ester are repeatedly bonded together; or polymeric compounds in which a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded together and a block in which structural units derived from an (α-substituted) acrylic acid are repeatedly bonded together; more preferred are polymeric compounds in which a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded together and a block in which structural units derived from an (α-substituted) acrylic acid ester are repeatedly bonded together; and even more preferred are polymeric compounds in which a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded together and a block in which structural units derived from a (meth)acrylic acid ester are repeatedly bonded together. Specific examples include polystyrene-polymethyl methacrylate (PS-PMMA) block copolymer, polystyrene-polyethyl methacrylate block copolymer, polystyrene-(poly-t-butyl methacrylate) block copolymer, polystyrene-polymethacrylic acid block copolymer, polystyrene-polymethyl acrylate block copolymer, polystyrene-polyethyl acrylate block copolymer, polystyrene-(poly-t-butyl acrylate) block copolymer, polystyrene-polyacrylic acid block copolymer, etc. Among these, PS-PMMA block copolymer is particularly preferred.

[0072] The number average molecular weight (Mn) of the block copolymer is not particularly limited as long as it is a size that allows phase separation to occur, but is preferably 5,000 or more and 500,000 or less, more preferably 30,000 or more and 300,000 or less, and even more preferably 50,000 or more and 200,000 or less. The molecular weight dispersity (Mw / Mn) of the block copolymer is preferably 1.0 or more and 3.0 or less, more preferably 1.0 or more and 1.5 or less, and even more preferably 1.0 or more and 1.2 or less.

[0073] The period (L0) of the structure containing the phase-separated structure produced using the block copolymer is not particularly limited, but is preferably 5 nm to 100 nm, more preferably 10 nm to 80 nm, and even more preferably 20 nm to 70 nm. In the base material of the first embodiment, the period may be, for example, 45 nm or more or 50 nm or more, since a phase-separated structure with good horizontal alignment can be formed even when the period of the structure is relatively large.

[0074] In this specification, the "period of the structure" refers to the period of the phase structure observed when a phase-separated structure is formed, and refers to the sum of the lengths of each phase that is incompatible with each other. When the phase-separated structure forms a cylindrical structure perpendicular to the substrate surface, the period (L0) of the structure is the center-to-center distance (pitch) between two adjacent cylindrical structures.

[0075] [Step (i)] In step (i), a base material is applied onto a substrate 1 to form a base material layer 2 . By providing the undercoat layer 2 on the substrate 1, a hydrophilic-hydrophobic balance can be achieved between the surface of the substrate 1 and the block copolymer-containing layer 3. In other words, the block copolymer (A) contained in the undercoat used in the undercoat layer 2 enhances adhesion between the phase consisting of the hydrophobic polymer block (b11) in the block copolymer-containing layer 3 and the substrate 1. This is thought to facilitate the formation of a phase-separated structure oriented horizontally relative to the surface of the substrate 1.

[0076] The type of substrate 1 is not particularly limited as long as it can have a base material applied to its surface. Examples include substrates made of inorganic materials such as silicon, metals (copper, chromium, iron, aluminum, etc.), glass, titanium oxide, silica, and mica; substrates made of oxides such as SiO2; substrates made of nitrides such as SiN; substrates made of oxynitrides such as SiON; and substrates made of organic materials such as acrylic resin, polystyrene, cellulose, cellulose acetate, and phenolic resin. Among these, silicon substrates (Si substrates) or metal substrates are preferred, Si substrates or copper substrates (Cu substrates) are more preferred, and Si substrates are particularly preferred. There are no particular limitations on the size or shape of the substrate 1. The substrate 1 does not necessarily have to have a smooth surface, and substrates of various shapes can be appropriately selected. Examples include substrates with a curved surface, flat plates with an uneven surface, and substrates in the shape of flakes.

[0077] The surface of the substrate 1 may be provided with an inorganic and / or organic film. Examples of inorganic films include inorganic anti-reflective coatings (inorganic BARCs), and examples of organic films include organic anti-reflective coatings (organic BARCs). The inorganic film can be formed, for example, by applying an inorganic anti-reflective coating composition made of a silicon-based material or the like onto a substrate and baking it. The organic film can be formed, for example, by applying an organic film-forming material, in which the resin components constituting the film are dissolved in an organic solvent, onto a substrate using a spinner or the like, and baking the material under heating conditions of preferably 200°C to 300°C, preferably 30 to 300 seconds, more preferably 60 to 180 seconds. This organic film-forming material does not necessarily need to be sensitive to light or electron beams, as is the case with resist films, and may or may not be sensitive. Specifically, resists and resins commonly used in the manufacture of semiconductor devices and liquid crystal display devices can be used. In addition, the organic film-forming material is preferably a material capable of forming an organic film that can be etched, particularly dry-etched, so that an organic film pattern can be formed by etching an organic film using a block copolymer pattern formed by processing the upper layer film. Among these, a material capable of forming an organic film that can be etched by oxygen plasma etching or the like is preferred. Such an organic film-forming material may be a material that has been conventionally used to form organic films such as organic BARC. Examples include the ARC series manufactured by Nissan Chemical Industries, Ltd., the AR series manufactured by Rohm and Haas, and the SWK series manufactured by Tokyo Ohka Kogyo Co., Ltd.

[0078] The method for applying the undercoat material onto the substrate 1 to form the undercoat material layer 2 is not particularly limited, and it can be formed by a conventionally known method. For example, the undercoat layer 2 can be formed by applying the undercoat onto the substrate 1 by a conventionally known method such as spin coating or using a spinner to form a coating film, and then drying it. The coating film can be dried by any method that can volatilize the solvent contained in the base material, such as baking. In this case, the baking temperature is preferably 200°C or lower. The base material of the first embodiment can obtain sufficient phase separation performance of the BCP composition even when the base material layer 2 is formed by heat treatment at a temperature of 200°C or lower. The baking temperature is preferably 150°C or higher and 200°C or lower, and more preferably 160°C or higher and 200°C or lower. The baking time is preferably 30 seconds or higher and 500 seconds or lower, more preferably 60 seconds or higher and 400 seconds or lower, even more preferably 100 seconds or higher and 300 seconds or lower, and even more preferably 100 seconds or higher and 200 seconds or lower. The baking time and baking temperature can be combined in any manner. The thickness of the base material layer 2 after drying of the coating film is preferably about 10 nm to 100 nm, more preferably about 20 nm to 90 nm, and even more preferably about 20 nm to 50 nm.

[0079] The surface of the substrate 1 may be cleaned before forming the base material layer 2 on the substrate 1. Cleaning the surface of the substrate 1 improves the applicability of the base material. As the cleaning treatment method, a conventionally known method can be used, for example, oxygen plasma treatment, ozone oxidation treatment, acid-alkali treatment, chemical modification treatment, etc.

[0080] After forming the base material layer 2, the base material layer 2 may be rinsed with a rinse liquid such as a solvent, if necessary. This rinsing removes polymers and other components in the base material layer 2 that have insufficient adhesion to the substrate, improving the affinity with at least one polymer (block) constituting the block copolymer, and facilitating the formation of a phase-separated structure oriented horizontally to the surface of the substrate 1. The rinse solution may be any solution capable of dissolving polymers that have insufficient adhesion to the substrate, and solvents such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), ethyl lactate (EL), or commercially available thinner solutions may be used. After the cleaning, post-baking may be performed to volatilize the rinse solution. The temperature conditions for this post-baking are preferably 80°C to 300°C, more preferably 100°C to 250°C, even more preferably 100°C to 200°C, and particularly preferably 100°C to 150°C. The baking time is preferably 30 seconds to 500 seconds, more preferably 60 seconds to 240 seconds. The thickness of the base material layer 2 after such post-baking is preferably about 1 nm to 10 nm, more preferably about 2 nm to 7 nm.

[0081] [Step (ii)] In step (ii), a layer 3 containing a block copolymer in which multiple types of blocks are bonded is formed on the base material layer 2. As the block copolymer, a block copolymer in which the above-mentioned hydrophobic polymer block (b11) and hydrophilic polymer block (b21) are bonded can be used. The method for forming layer 3 on undercoat layer 2 is not particularly limited, and examples thereof include a method in which a BCP composition is applied to undercoat layer 2 by a conventionally known method such as spin coating or using a spinner to form a coating film, and then dried. Details of the BCP composition will be described later.

[0082] The thickness of layer 3 need only be sufficient for phase separation to occur, and taking into consideration the type of substrate 1, the structural period size of the phase-separated structure to be formed, the uniformity of the nanostructure, etc., a thickness of 20 nm to 100 nm is preferred, and a thickness of 30 nm to 80 nm is more preferred. For example, when the substrate 1 is a Cu substrate, the thickness of the layer 3 is preferably 10 nm or more and 100 nm or less, and more preferably 30 nm or more and 80 nm or less.

[0083] [Step (iii)] In step (iii), the layer 3 containing the block copolymer is subjected to phase separation. By heating and annealing the substrate 1 after step (ii), the block copolymer is selectively removed to form a phase-separated structure that exposes at least a portion of the surface of the substrate 1. That is, a structure 3′ is produced on the substrate 1, which includes a phase-separated structure separated into phases 3a and 3b. The annealing temperature is preferably above the glass transition temperature of the block copolymer used and below its thermal decomposition temperature. For example, when the block copolymer is a polystyrene-polymethyl methacrylate (PS-PMMA) block copolymer (weight-average molecular weight: 5,000 to 100,000), the annealing temperature is preferably 180°C to 290°C. The heating time is preferably 30 seconds to 3,600 seconds. The annealing process is preferably carried out in a gas with low reactivity, such as nitrogen.

[0084] [Optional process] The method for producing a structure containing a phase-separated structure is not limited to the above-described embodiment, and may include steps (optional steps) other than steps (i) to (iii). Such optional steps include a step of selectively removing a phase consisting of at least one type of block among the multiple types of blocks constituting the block copolymer from a layer containing the block copolymer (hereinafter referred to as "step (iv)"), a guide pattern formation step, and the like.

[0085] Regarding step (iv) In step (iv), a phase consisting of at least one type of block among the multiple types of blocks constituting the block copolymer is selectively removed from the layer containing the block copolymer formed on the underlayer, thereby forming a fine pattern (polymer nanostructure).

[0086] Examples of a method for selectively removing the phase consisting of blocks include a method of subjecting a layer containing a block copolymer to oxygen plasma treatment, a method of subjecting a layer containing a block copolymer to hydrogen plasma treatment, and the like. In the following, among the blocks constituting the block copolymer, the block that is not selectively removed is referred to as P A block, the block to be selectively removed is P B For example, after phase separation of a layer containing a PS-PMMA block copolymer, the layer is subjected to oxygen plasma treatment or hydrogen plasma treatment, etc., to selectively remove the PMMA phase. In this case, the PS portion is P A The PMMA part is P B It is a block.

[0087] FIG. 2 shows an example embodiment of step (iv). In the embodiment shown in Figure 2, the structure 3' produced on the substrate 1 in step (iii) is subjected to oxygen plasma treatment, whereby the phase 3a is selectively removed, forming a pattern (polymer nanostructure) consisting of spaced phases 3b. In this case, the phase 3b is P A Phase 3a is a phase consisting of P B It is a phase made up of blocks.

[0088] The substrate 1 on which a pattern has been formed by phase separation of the layer 3 made of the block copolymer as described above can be used as is, but the shape of the pattern (polymer nanostructure) on the substrate 1 can also be changed by further heating. The heating temperature is preferably equal to or higher than the glass transition temperature of the block copolymer used and lower than its thermal decomposition temperature, and is preferably carried out in a low-reactivity gas such as nitrogen.

[0089] Guide pattern formation process The method for producing a structure containing a phase-separated structure may include a step of providing a guide pattern on the underlayer (guide pattern forming step) between steps (i) and (ii), which allows for control of the arrangement of the phase-separated structure. For example, even if a block copolymer forms a random, fingerprint-like phase-separated structure without a guide pattern, by providing a groove structure of the resist film on the surface of the base material layer, a phase-separated structure oriented along the groove can be obtained. Based on this principle, a guide pattern may be provided on the base material layer 2.

[0090] The guide pattern can be formed using, for example, a resist composition. The resist composition for forming the guide pattern can be appropriately selected from resist compositions generally used for forming resist patterns or their modifications, and can be one that has affinity with any of the polymers constituting the block copolymer. The resist composition can be either a positive resist composition that forms a positive pattern in which the exposed portion of the resist film is dissolved and removed, or a negative resist composition that forms a negative pattern in which the unexposed portion of the resist film is dissolved and removed, but a negative resist composition is preferred. A preferred negative resist composition is, for example, a resist composition that contains an acid generator and a base component whose solubility in a developer containing an organic solvent decreases under the action of acid, and the base component contains a resin component having a structural unit that decomposes under the action of acid to increase its polarity. After the BCP composition is poured onto the base material layer on which the guide pattern is formed, an annealing treatment is performed to cause phase separation. Therefore, the resist composition for forming the guide pattern is preferably one that can form a resist film with excellent solvent resistance and heat resistance.

[0091] Compositions containing block copolymers (BCP compositions) The BCP composition can be prepared by dissolving the block copolymer in an organic solvent, such as the same organic solvents as those used in the solvent (S) for the base material. The organic solvent contained in the BCP composition is not particularly limited and is set at a coatable concentration appropriately depending on the coating film thickness. Generally, the organic solvent is used so that the solids concentration of the block copolymer is in the range of 0.2% by mass or more and 70% by mass or less, preferably 0.2% by mass or more and 50% by mass or less.

[0092] In addition to the block copolymer and organic solvent, the BCP composition may optionally contain miscible additives such as additional resins for improving the performance of the undercoat layer, surfactants for improving coatability, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, sensitizers, base amplifiers, and basic compounds.

[0093] FIG. 3 is a schematic diagram showing an example of a structure containing a phase-separated structure produced by the production method of this embodiment. In FIG. 3, "lamellar composition BCP" refers to the case where a block copolymer that forms a lamellar phase-separated structure is used. "cylindrical composition BCP" refers to the case where a block copolymer that forms a cylindrical phase-separated structure is used. By adjusting the composition of the block copolymer (such as the molecular weight and molar ratio of each block), a lamellar composition BCP or a cylindrical composition BCP can be obtained.

[0094] For example, if the first embodiment of the primer has affinity for the polymer block that constitutes phase 3a, step (i) forms a phase 3a-affinity primer layer 2a (Figure 3, top left column). Then, steps (ii) and (iii) form a phase-separated structure, which can form a lamellar structure (Figure 3, middle left column) or a cylindrical structure (Figure 3, bottom left column), depending on the composition of the block copolymer. In the lamellar structure, phase 3a is in contact with the phase 3a-affinity primer layer 2a, forming a horizontal lamellar structure. In the cylindrical structure, phase 3a cylinders are in contact with the phase 3a-affinity primer layer 2a, forming a horizontal cylindrical structure. The top left column of Figure 4 shows an example of an SEM aerial photograph of a horizontal lamellar phase-separated structure formed using a base material layer 2a with affinity for phase 3a. In the horizontal lamellae, phases 3a and 3b are repeatedly stacked horizontally, so no pattern is observed in the SEM aerial photograph. The bottom left column of Figure 4 shows an example of an SEM aerial photograph of a horizontal cylindrical phase-separated structure formed using a phase 3a-compatible base layer 2a. Because no guide pattern was used, the horizontal cylinders (lateral cylinders) have a wavy shape.

[0095] For example, if the first embodiment of the primer has affinity for the polymer block constituting phase 3b, step (i) forms a phase 3b-affinity primer layer 2b (Figure 3, top right column). Then, steps (ii) and (iii) form a phase-separated structure, which can result in a lamellar structure (Figure 3, middle right column) or a cylindrical structure (Figure 3, bottom right column), depending on the composition of the block copolymer. In the lamellar structure, phase 3b is in contact with the phase 3b-affinity primer layer 2b, resulting in a horizontal lamellar structure. In the cylindrical structure, phase 3a cylinders are not in contact with the phase 3b-affinity primer layer 2a, resulting in a horizontal cylindrical structure. The top right column of Figure 4 shows an example of an SEM aerial photograph of a horizontal lamellar phase-separated structure formed using a base material layer 2b with affinity for phase 3b. In the horizontal lamella, phases 3b and 3a are repeatedly stacked horizontally, so no pattern is observed in the SEM aerial photograph. The bottom right column of Figure 4 shows an example of an SEM aerial photograph of a horizontal cylindrical phase-separated structure formed using a phase 3b-compatible base layer 2b. Because no guide pattern was used, the horizontal cylinders (lateral cylinders) have a wavy shape.

[0096] For example, if the primer has affinity for both the polymer blocks of phase 3a and phase 3b, a primer layer 2ab with affinity for both phases is formed by step (i) (upper middle row). Then, a phase-separated structure is formed by steps (ii) and (iii), which can result in a lamellar structure (middle middle row) or a cylindrical structure (lower middle row) depending on the composition of the block copolymer. In the lamellar structure, a vertical lamellar structure is formed in which repeating structures of phases 3a and 3b are perpendicularly formed relative to the primer layer 2ab with affinity for both phases. In the cylindrical structure, a vertical cylindrical structure is formed in which cylinders of phase 3a are perpendicularly formed relative to the primer layer 2ab with affinity for both phases. The top row in the middle column of Figure 4 shows an example of an SEM aerial photograph of a vertical lamellar phase-separated structure formed using the amphoteric base layer 2ab. Because no guide pattern was used, wavy (fingerprint) vertical lamellae are observed. The bottom middle row in Figure 4 shows an example of an SEM aerial photograph of a vertical cylindrical phase-separated structure formed using the amphoteric base material layer 2ab. Because no guide pattern was used, the vertical cylinders (longitudinal cylinders) are randomly arranged.

[0097] The polymer block constituting the phase 3a may be a hydrophobic polymer block (b11), and the polymer block constituting the phase 3b may be a hydrophilic polymer block (b21). The hydrophobic polymer block (b11) is not particularly limited as long as it has a relatively low affinity for water compared to the hydrophilic polymer block (b21), and examples thereof include a block in which structural units derived from styrene or a styrene derivative are repeatedly bonded. The hydrophilic polymer block (b21) is not particularly limited as long as it has a relatively high affinity for water compared to the hydrophobic polymer block (b11). Examples of the hydrophilic polymer block (b21) include a block in which structural units derived from an (α-substituted) acrylic acid ester are repeatedly bonded, and a block in which structural units derived from an (α-substituted) acrylic acid are repeatedly bonded.

[0098] The manufacturing method of this embodiment can be suitably used for manufacturing a structure containing a horizontal lamellar or horizontal cylindrical phase-separated structure. The base material of the first embodiment tends to have a high affinity with the hydrophobic polymer block (b11). Therefore, it is suitable for manufacturing a structure containing a horizontal lamellar phase-separated structure as shown in the middle of the left column of Figure 3 or a horizontal cylindrical phase-separated structure as shown in the bottom of the left column of Figure 3.

[0099] As described above, the present inventors provide the following (1) to (5). (1) A base material used to phase separate a layer containing a block copolymer, Contains a block copolymer (A), The block copolymer (A) has a block (A1) and a block (A2), The block (A1) has a structural unit represented by the following formula (a1): The block (A2) has a structural unit represented by the following formula (a2): the block copolymer (A) does not have a structural unit derived from a (meth)acrylic acid alkyl ester, a ratio of the number of moles of the structural units constituting the block (A2) to the total number of moles of the structural units constituting the block (A1) and the number of moles of the structural units constituting the block (A2) is more than 0 mol % and 40 mol % or less. [ka] (In formula (a1), R a11 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R a12 is a substituent, and n is an integer of 0 or more and 5 or less. In formula (a2), R a21 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L 1 is a single bond or a divalent linking group, and Y 1 is a divalent linking group having 1 to 15 carbon atoms. (2) The base material according to (1), wherein the block copolymer (A) does not have any blocks other than the block (A1) and the block (A2). (3) The above R a12 is an alkyl group having from 1 to 5 carbon atoms, Said L 1 is a single bond or -C(=O)-O-, The Y 1 is a divalent hydrocarbon group having 1 to 15 carbon atoms which may have a substituent. (4) The base material according to any one of (1) to (3), wherein the ratio of the number of moles of the structural units of the block (A2) to the total number of moles of the structural units of the block (A1) and the number of moles of the structural units of the block (A2) is 3 mol % or more and 35 mol % or less. (5) Applying the base material according to any one of (1) to (4) onto a substrate to form a base material layer; forming a layer containing the block copolymer on the underlayer; and phase-separating the layer containing the block copolymer. [Example]

[0100] The present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0101] <Synthesis of block copolymers used in base materials> [Synthesis of block copolymer (P-1)] Under an argon atmosphere, 2.06 g (48.7 mmol) of LiCl and 162 g of tetrahydrofuran (THF) were placed in a Schlenk tube and cooled to -78 °C. After dehydrating and degassing the tube, 13.2 mL (1.23 mol / L hexane / cyclohexane mixed solution, 16.2 mmol) of sec-butyllithium was added as an anionic polymerization initiator under an argon atmosphere, followed by 22.1 mL (192 mmol) of compound (A'-1). The mixture was stirred at -78 °C for 30 minutes. Next, 4.3 mL (24.3 mmol) of 1,1-diphenylethylene (DPE) was added to the tube and stirred at -78 °C for 60 minutes. Next, 9.0 mL (42.4 mmol) of compound (B'-1) was added to the tube and stirred at -78 °C for 180 minutes. Furthermore, 1 mL (25 mmol) of methanol was added to the tube as a polymerization terminator at −78° C. to terminate the reaction, thereby obtaining a reaction polymerization liquid. 50 mL of 5% hydrochloric acid was added to the reaction polymerization solution and stirred at room temperature for 120 minutes. Next, the reaction polymerization solution was added dropwise to a large amount of methanol to precipitate a polymer. The precipitated white powder was collected by filtration and dissolved in 114 g of THF. 50 mL of 5% hydrochloric acid was added to the THF solution and stirred at room temperature for 60 minutes. Next, the THF solution was added dropwise to a large amount of methanol to precipitate a polymer. The precipitated white powder was washed with a large amount of methanol, then with a large amount of pure water, and then dried to obtain 21.5 g (yield 75.4%) of block copolymer (P-1).

[0102] [ka]

[0103] [Synthesis of block copolymers (P-2) to (P-18)] Block copolymers (P-2) to (P-18) having a constitutional unit represented by the following formula (A-1) or (A-2) and a constitutional unit represented by any of the following formulas (B-1) to (B-9) were synthesized using compound (A'-1) or (A'-2) represented by the following formula and any of compounds (B'-1) to (B'-9) represented by the following formulas in which the hydroxy group is protected with a trimethylsilyl group or an acetal structure, in a manner similar to the synthesis of block copolymer (P-1), including polymerization of each compound and elimination of the protecting group.

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] The structures of block copolymers (P-1) to (P-18) are as follows: 13 This was confirmed by C-NMR.

[0109] Polymers (P-1) to (P-5), (P-15), (P-16), and (P-18) 13 C-NMR (600MHz, CDCl3):20-22ppm(α-CH3), 40-50ppm(backbone), 63ppm(CH2OH), 70ppm(OCH2), 125-131ppm(Ar, CH), 141-145ppm(Ar, C), 178ppm(C=O)

[0110] Polymer (P-6) 13C-NMR(600MHz、CDCl3):20-22ppm(α-CH3), 24-35ppm(CH2), 40-50ppm(backbone), 63ppm(CH2OH), 67ppm(OCH2), 125-131ppm(Ar, CH), 140-144ppm(Ar, C), 174ppm(C=O)

[0111] ·                 (P-7) 13 C-NMR(600MHz、CDCl3):20-22ppm(α-CH3), 24-35ppm(Cy、CH2·CH), 40-50ppm(backbone), 67ppm(CH2OH), 72ppm(OCH2), 125-131ppm(Ar, CH), 140-144ppm(Ar, C), 175ppm(C=O)

[0112] ·                 (P-8) 13 C-NMR(600MHz、CDCl3):20-22ppm(α-CH3), 40-50ppm(backbone), 69ppm(CH2OH), 73ppm(OCH2), 125-131ppm(Ar,CH), 138-144ppm(Ar,C), 176ppm(C=O);

[0113] ·               (P-9) 13 C-NMR(600MHz、CDCl3):20-50ppm(α-CH3, backbone, Ad), 61-62ppm(-OCH2CH2OH), 73ppm(Ad, CO), 82ppm(Ad, OC), 125-130ppm(Ar, CH), 138-145ppm(Ar, C), 178ppm(C=O)

[0114] ·                (P-10) 13C-NMR(600MHz、CDCl3):20-22ppm(α-CH3), 40-50ppm(backbone), 67ppm(CH2OH), 71ppm(OCH2), 75ppm(CHOH), 125-130ppm(Ar,CH), 138-144ppm(Ar,C), 176ppm(C=O);

[0115] ·                  (P-11) 13 C-NMR(600MHz、CDCl3):20-22ppm(α-CH3), 40-50ppm(backbone), 61-62ppm(CH2OH), 64ppm(CHOH), 70-74ppm(CH, CHOH), 95ppm(OCHOH), 125-130ppm(Ar, CH), 138-144ppm(Ar,C), 176ppm(C=O)

[0116] ·                (P-12) 13 C-NMR(600MHz、CDCl3):20-22ppm(α-CH3), 38-39ppm(C), 40-50ppm(backbone), 59-61ppm(CH2OH), 63ppm(OCH2), 125-130ppm(Ar, CH), 138-144ppm(Ar, C), 177ppm(C=O)

[0117] · Lion (P-13) and (P-14) 13 C-NMR(600MHz、CDCl3):40-50ppm(backbone), 68-69ppm(CH2OH), 125-130ppm(Ar,CH), 138-144ppm(Ar,C);

[0118] ·                  (P-17) 13C-NMR (600MHz, CDCl3): 19-22ppm(α-CH3, Ar-CH3), 40-50ppm(backbone), 63ppm(CH2OH), 70ppm(OCH2), 127-130ppm(Ar, CH), 135-137ppm(Ar, C), 177ppm(C=O)

[0119] Block copolymers (P-1) to (P-18) 13 The molar ratio of each structural unit, the number average molecular weight (Mn), and the molecular weight dispersity (Mw / Mn) determined by C-NMR (600 MHz) are shown in Table 1.

[0120] In the comparative examples, the following polymers (P-19) and (P-20) were also used. The molar ratio of each structural unit, number average molecular weight (Mn), and molecular weight dispersity (Mw / Mn) are shown in Table 1. Polymer (P-19): A random copolymer having a constitutional unit represented by the following formula. [ka] Polymer (P-20): A polymer represented by the following formula. [ka]

[0121] The molar ratio of each structural unit was measured using an NMR device (manufactured by Bruker, equipped with a CryoProbe). 13 The integral ratio (area ratio) was calculated from the chemical shift of each structural unit of the polymer by C-NMR measurement (600 MHz, CDCl3, 1024 times of accumulation).

[0122] [Table 1]

[0123] <Preparation of base material> Each example composition was prepared by mixing the type of polymer listed in Table 2 with propylene glycol monomethyl ether acetate (PGMEA) to a concentration of 1.0 wt %.

[0124] <Synthesis of block copolymers used for phase separation> [Synthesis of block copolymer (BCP-1)] Under an argon atmosphere, 0.12 g (2.93 mmol) of LiCl and 161 g of THF were placed in a Schlenk flask and cooled to -78 °C. After dehydrating and degassing the tube, 0.27 ml (1.07 mol / l hexane-cyclohexane mixed solution, 0.29 mmol) of sec-butyllithium was added as an anionic polymerization initiator under an argon atmosphere, followed by 22.1 ml (192 mmol) of styrene. The mixture was stirred at -78 °C for 30 minutes. Next, 0.077 ml (0.44 mmol) of DPE was added to the tube and stirred at -78 °C for 30 minutes. Next, 9.03 ml (84.80 mmol) of methyl methacrylate was added to the tube and stirred at -78 °C for 180 minutes. Furthermore, 1 ml (25 mmol) of methanol was added to the tube as a polymerization terminator at −78° C. to terminate the reaction, thereby obtaining a reaction polymerization liquid. The reaction mixture was added dropwise to a large amount of methanol to precipitate the polymer. The precipitated white powder was washed with a large amount of methanol, then with a large amount of pure water, and then dried to obtain 21.8 g (yield 73.8%) of block copolymer (BCP-1). The block copolymer (BCP-1) had a number average molecular weight of 98,500 and a molecular weight dispersity of 1.05. 13 The molar ratio of each structural unit determined by C-NMR (600 MHz) was 69.8 mol % for m and 30.2 mol % for n.

[0125] [ka]

[0126] [Synthesis of block copolymer (BCP-2)] Block copolymer (BCP-2) having a structural unit represented by the following formula was synthesized in the same manner as in the synthesis of block copolymer (BCP-1). The number average molecular weight of block copolymer (BCP-2) was 160,100, and the molecular weight dispersity was 1.03. 13 The molar ratio of each structural unit determined by C-NMR (600 MHz) was 62.5 mol % for m and 37.5 mol % for n. [ka]

[0127] <Preparation of Resin Composition for Forming Phase-Separated Structure> 100 parts by mass of BCP-1, 14 parts by mass of PS, 6 parts by mass of PMMA, and PGMEA were mixed to prepare a phase-separated structure-forming resin composition 1 (solid content: approximately 1.6% by mass). Furthermore, 100 parts by mass of BCP-2, 38 parts by mass of PS, 22 parts by mass of PMMA, and PGMEA were mixed to prepare a phase-separated structure-forming resin composition 2 (solid content concentration: approximately 2.0% by mass).

[0128] The PS and PMMA used are as follows: PS: Polystyrene (number average molecular weight: 2,000, molecular weight dispersity: 1.03) PMMA: Polymethyl methacrylate (number average molecular weight: 2,000, molecular weight dispersity: 1.03)

[0129] The phase-separated structure-forming resin composition 1 was applied to a neutral film, and the period of the structures obtained by phase separation was 40 nm. Similarly, the phase-separated structure-forming resin composition 2 was applied to a neutral film, and the period of the structures obtained by phase separation was 53 nm. The polymer used for the neutral membrane was a random copolymer of styrene / methyl methacrylate / 2-hydroxyethyl methacrylate (copolymerization ratio: 82 / 12 / 6 (mass%), number average molecular weight: 45,600, molecular weight dispersity: 1.76).

[0130] <Measurement of the contact angle of water on the surface of the base material layer> Each example of the primer was applied to a 12-inch silicon wafer substrate that had been dehydrobaked at 150°C for 60 seconds using a spinner (1500 rpm). The applied film was dried by baking at 160°C or 240°C for 120 seconds to form a 25 nm thick primer layer. The primer layer was rinsed with OK73 thinner (Tokyo Ohka Kogyo Co., Ltd.) to remove any polymer that was not adhered to the substrate. It was then baked at 100°C for 60 seconds. Water was dropped onto the surface of the base material layer, and the contact angle (static contact angle) was measured using a DROP MASTER-700 (Kyowa Interface Science Co., Ltd.) (contact angle measurement: 2 μL of water). The contact angles when the base material was baked at 160°C or 240°C are shown in Table 2 as "160°C" and "240°C" under "Contact angle (°)," respectively. The difference between the contact angle at 240°C and the contact angle at 160°C (contact angle at 240°C - contact angle at 160°C) is also shown in Table 2 as "Δ."

[0131] <Evaluation of horizontal alignment when the period of the structure is 40 nm> (Step (i)) Each example of the primer was applied to a 12-inch silicon wafer substrate that had been dehydrobaked at 150°C for 60 seconds using a spinner (1500 rpm). The applied film was baked at 200°C for 120 seconds to dry, forming a 25 nm thick primer layer. The primer layer was rinsed with OK73 thinner (Tokyo Ohka Kogyo Co., Ltd.) to remove any polymer that was not adhered to the substrate. It was then baked at 100°C for 60 seconds.

[0132] (Step (ii)) The phase-separated structure-forming resin composition 1 was applied to the undercoat layer by spin coating (rotation speed: 1500 rpm). The applied film was baked at 90°C for 60 seconds to dry, thereby forming a layer containing a block copolymer with a thickness of 52 nm.

[0133] (Step (iii)) The layer containing the block copolymer was annealed by heating at 260°C for 15 minutes under a nitrogen stream, causing phase separation into a polystyrene phase and a polymethyl methacrylate phase, forming a phase-separated structure.

[0134] (Step (iv)) The substrate on which the phase-separated structure was formed was irradiated with ultraviolet light (λ172 nm, 160 mJ) under a nitrogen atmosphere using a CLEAN TRACK LITHIUS Pro-Z (Tokyo Electron Ltd.).Then, development was carried out with isopropyl alcohol to selectively remove the polymethyl methacrylate phase.

[0135] The surface (phase-separated state) of the obtained substrate was observed with a critical dimension SEM (scanning electron microscope, product name CG6300, manufactured by Hitachi High-Technologies Corporation, accelerating voltage 800 eV, current value 15 pA, Frame 256, magnification 100k (image of 1350 nm square)). From the observation results, horizontal alignment was evaluated based on the following evaluation criteria. The results are shown in Table 2 under "40 nm" for "horizontal alignment." A: Complete horizontal orientation (horizontal cylinder) was observed. B: Vertically oriented (vertical cylinder) portions were observed.

[0136] <Evaluation of horizontal alignment when the period of the structure is 53 nm> A phase-separated structure was formed and the phase consisting of polymethyl methacrylate was selectively removed in the same manner as in <Evaluation of horizontal alignment property when the period of the structure is 40 nm>, except that in the above step (ii), a layer containing a block copolymer with a thickness of 60 nm was formed using resin composition 2 for forming a phase-separated structure instead of resin composition 1 for forming a phase-separated structure, and annealing was performed at 280°C in the above step (iii).

[0137] The surface (phase-separated state) of the obtained substrate was imaged using a critical dimension SEM (scanning electron microscope, product name CG6300, manufactured by Hitachi High-Technologies Corporation, accelerating voltage 800 eV, current value 15 pA, Frame 256, magnification 100k (image of 1350 nm square)). From the results of observing the image, horizontal alignment was evaluated based on the following evaluation criteria. The results are shown in "53 nm" under "horizontal alignment" in Table 2. Specific examples of images showing phase-separated states corresponding to evaluations A to D are shown in Figure 5. A: Complete horizontal alignment was observed B: The area of ​​the horizontally oriented portion was 90% or more and less than 100% of the image area. C: The area of ​​the horizontally oriented portion was 50% or more and less than 90% of the image area. D: The area of ​​the horizontally oriented portion was less than 50% of the image area.

[0138] [Table 2]

[0139] As shown in Table 2, in Examples 1 to 17, in which a predetermined block copolymer (A) was used as the base material, the 160°C contact angle was high and the difference between the 240°C contact angle and the 160°C contact angle was small. Furthermore, in Examples 1 to 17, even when the period of the structural body was relatively large, good horizontal alignment was achieved. On the other hand, in Comparative Examples 1 to 3, in which a polymer other than the predetermined block copolymer (A) was used as the base material, good horizontal alignment was achieved when the period of the structural body was relatively small, but good horizontal alignment was not achieved when the period of the structural body was relatively large. [Explanation of symbols]

[0140] 1 board 2 Base layer 2a Phase 3a compatible base material layer 2b Phase 3b compatible base material layer 2ab Compatible base material layer 3. Layer containing block copolymer 3' structure 3a phase 3b phase

Claims

1. A base material used to phase separate a layer containing a block copolymer, Contains a block copolymer (A), The block copolymer (A) has a block (A1) and a block (A2), The block (A1) has a structural unit represented by the following formula (a1): The block (A2) has a structural unit represented by the following formula (a2): the block copolymer (A) does not have a structural unit derived from a (meth)acrylic acid alkyl ester, a ratio of the number of moles of the structural units constituting the block (A2) to the sum of the number of moles of the structural units constituting the block (A1) and the number of moles of the structural units constituting the block (A2) is more than 0 mol% and 40 mol% or less. 【Chemistry 1】 (In formula (a1), R ａ１１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R ａ１２ is a substituent, and n is an integer of 0 or more and 5 or less. In formula (a2), R ａ２１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L １ is a single bond or a divalent linking group, and Y １ is a divalent linking group having 1 to 15 carbon atoms.

2. The base material according to claim 1 , wherein the block copolymer (A) does not have any blocks other than the block (A1) and the block (A2).

3. The R ａ１２ is an alkyl group having from 1 to 5 carbon atoms, Said L １ is a single bond or —C(═O)—O—, The Y １ 2. The primer of claim 1, wherein is a divalent hydrocarbon group having 1 to 15 carbon atoms, which may have a substituent.

4. 2. The base material according to claim 1, wherein the ratio of the number of moles of the structural units of the block (A2) to the total number of moles of the structural units of the block (A1) and the number of moles of the structural units of the block (A2) is 3 mol % or more and 35 mol % or less.

5. Applying the base material according to any one of claims 1 to 4 onto a substrate to form a base material layer; forming a layer containing the block copolymer on the underlayer; and phase-separating the layer containing the block copolymer.

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