Resin composition for forming phase-separated structure, method for producing structure having phase-separated structure, and block copolymer

Abstract

To provide a resin composition for forming a phase-separated structure capable of forming a phase-separated structure having an excellent vertical orientation, a method for producing a structure having a phase-separated structure using the same, and a block copolymer for use in the resin composition for forming a phase-separated structure.SOLUTION: In a resin composition for forming a phase-separated structure, a first block comprises a polymer having a repeating structure of a constituent unit represented by the formula (b1) in the figure, and a second block comprises a random copolymer having a structure in which a constituent unit represented by the formula (b2a) in the figure and a constituent unit represented by the formula (b2b) in the figure are randomly arranged, where the ratio of the volume of the first block is from 20 vol.% to 80 vol% inclusive.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition for forming a phase separation structure, a method for manufacturing a structure including the phase separation structure, and a block copolymer.

Background Art

[0002] In recent years, with the further miniaturization of large-scale integrated circuits (LSIs), technologies for processing more delicate structures have been demanded. In response to such demands, technologies for forming finer patterns have been developed by utilizing a phase separation structure formed by self-organization of a block copolymer in which blocks that are incompatible with each other are bonded (see, for example, Patent Document 1). In order to utilize the phase separation structure of a block copolymer, it is essential to form a self-organized nanostructure formed by microphase separation only in a specific region and arrange it in a desired direction. In order to achieve these position control and orientation control, processes such as graphoepitaxy that controls the phase separation pattern by a guide pattern and chemical epitaxy that controls the phase separation pattern by differences in the chemical state of the substrate have been proposed (see, for example, Non-Patent Document 1).

[0003] A block copolymer forms a structure having a regular periodic structure by phase separation. The "period of the structure" means the period of the phase structure observed when a structure of the phase separation structure is formed, and refers to the sum of the lengths of each phase that is incompatible with each other. When the phase separation structure forms a cylinder structure perpendicular to the substrate surface, the period (L0) of the structure is the center-to-center distance (pitch) between two adjacent cylinder structures.

[0004] The period (L0) of the structure is known to be determined by the degree of polymerization N and the inherent polymerization characteristics such as the Flory-Huggins interaction parameter χ. That is, the larger the product “χ·N” of χ and N, the greater the mutual repulsion between different blocks in the block copolymer. Therefore, when χ·N > 10.5 (hereinafter referred to as the “strength separation limit point”), the repulsion between different types of blocks in the block copolymer is large, and the tendency of phase separation to occur becomes strong. And at the strength separation limit point, the period of the structure is approximately N 2 / 3 ·χ 1 / 6 and the relationship of the following formula (1) holds. That is, the period of the structure is proportional to the degree of polymerization N that correlates with the molecular weight and the molecular weight ratio between different blocks.

[0005] L0 ∝ a·N 2 / 3 ·χ 1 / 6 ···(1) [In the formula, L0 represents the period of the structure. a is a parameter indicating the size of the monomer. N represents the degree of polymerization. χ is the interaction parameter, and the larger this value, the higher the phase separation performance.]

[0006] Therefore, by adjusting the composition and total molecular weight of the block copolymer, the period (L0) of the structure can be adjusted. The periodic structure formed by the block copolymer changes to a cylinder (columnar), lamella (plate-like), sphere (spherical) with the volume ratio of the polymer components, etc., and its period is known to depend on the molecular weight. Therefore, in order to form a structure with a relatively large period (L0) by utilizing the phase separation structure formed by the self-organization of the block copolymer, a method of increasing the molecular weight of the block copolymer can be considered.

[0007] In addition, a method using a block copolymer having a larger interaction parameter (χ) than a block copolymer having a styrene block and a methyl methacrylate block, which is a general-purpose block copolymer, can be considered. For example, Non-Patent Document 2 proposes a block copolymer composed of a styrene block and a 2-hydroxy-3-(2,2,2-trifluoroethylsulfanyl)propyl methacrylate block.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Non-Patent Documents

[0009]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] In order to form a fine pattern by utilizing the phase separation structure formed by the self-organization of a block copolymer, it is preferable that the phase separation structure formed by the block copolymer has perpendicular orientation. However, the block copolymer described in Non-Patent Document 2 cannot form a phase separation structure having perpendicular orientation.

[0011] The present invention has been made in view of the above circumstances, and an object thereof is to provide a resin composition for forming a phase separation structure capable of forming a phase separation structure excellent in vertical alignment, a method for manufacturing a structure including the phase separation structure using the same, and a block copolymer used for the resin composition for forming the phase separation structure.

Means for Solving the Problems

[0012] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a predetermined block copolymer, and have completed the present invention. Specifically, the present invention provides the following.

[0013] A first aspect is a resin composition for forming a phase separation structure containing a block copolymer having a first block and a second block, wherein the first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1), the second block is composed of a random copolymer having a structure in which a structural unit represented by the following formula (b2a) and a structural unit represented by the following formula (b2b) are randomly arranged, and a ratio of a volume of the first block to a total of the volume of the first block and the volume of the second block is 20% by volume or more and 80% by volume or less.

Chemical formula

[0014] A second aspect is to apply the resin composition for forming a phase separation structure of the first aspect on a support to form a layer containing the block copolymer, and phase-separating the layer containing the block copolymer, which is a method for producing a structure having a phase separation structure.

[0015] A third aspect is a block copolymer having a first block and a second block, wherein the first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1), the second block is composed of a random copolymer having a structure in which a structural unit represented by the following formula (b2a) and a structural unit represented by the following formula (b2b) are randomly arranged, and the ratio of the volume of the first block to the total volume of the first block and the second block is 20% by volume or more and 80% by volume or less.

Chemical formula

[0016] According to the present invention, it is possible to provide a resin composition for forming a phase separation structure capable of forming a phase separation structure excellent in vertical alignment, a method for manufacturing a structure including the phase separation structure using the same, and a block copolymer used for the resin composition for forming the phase separation structure. [Brief Description of the Drawings]

[0017]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0019] In this specification, "aliphatic" is a relative concept with respect to aromatic, and means a group, compound, etc. having no aromaticity. "Alkyl group" means a linear or branched monovalent saturated hydrocarbon group unless otherwise specified. The same applies to the alkyl group in the alkoxy group. "Cycloalkyl group" means a monocyclic cyclic saturated hydrocarbon group unless otherwise specified. "Alkylene group" means a linear or branched divalent saturated hydrocarbon group unless otherwise specified. "Halogenated alkyl group" means a group in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. "Fluorinated alkyl group" or "fluorinated alkylene group" means a group in which some or all of the hydrogen atoms of the alkyl group or alkylene group are substituted with fluorine atoms. "Constituent unit" means a monomer unit (monomeric unit) that constitutes a polymer compound (resin, polymer, copolymer). "Derived constituent unit" means a constituent unit formed by cleavage of an ethylenic double bond or a cyclic ether. When it is described as "may have a substituent", it includes both the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH2-) with a divalent group. "Exposure" means irradiation with radiation in general. The term "α-position (α-carbon atom)" means, unless otherwise specified, the carbon atom to which the side chain of the block copolymer is attached. The "α-carbon atom" of a methyl methacrylate unit means the carbon atom to which the carbonyl group of methacrylic acid is attached. The "α-carbon atom" of a styrene unit means the carbon atom to which the benzene ring is attached. The "number average molecular weight" (Mn) means, unless otherwise specified, the number average molecular weight in terms of standard polystyrene measured by size exclusion chromatography. The "weight average molecular weight" (Mw) means, unless otherwise specified, the weight average molecular weight in terms of standard polystyrene measured by size exclusion chromatography. When the value of Mn or Mw is given with the unit (g / mol), the value represents the molar mass. -1 In this specification, depending on the structure represented by a chemical formula, there may be an asymmetric carbon, and enantiomers or diastereomers may exist. In that case, those isomers are represented by one formula. Those isomers may be used alone or as a mixture.

[0020] ≪Resin Composition for Forming Phase Separation Structure≫ The resin composition for forming a phase separation structure contains a block copolymer having a first block and a second block. The first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1). The second block is composed of a random copolymer having a structure in which a structural unit represented by the following formula (b2a) and a structural unit represented by the following formula (b2b) are randomly arranged. The ratio of the volume of the first block to the total of the volume of the first block and the volume of the second block is 20% by volume or more and 80% by volume or less.

[0021]

Chemical Formula

[0022] <Block copolymer> A block copolymer is a polymer in which a plurality of types of blocks (sub-constituents in which the same type of constitutional unit is repeatedly bonded) are bonded. The blocks constituting the block copolymer may be two types or three or more types. The block copolymer has a first block and a second block.

[0023] [First block] The first block is composed of a polymer having a repeating structure of a constitutional unit represented by the following formula (b1) (hereinafter also referred to as constitutional unit (b1)).

[0024] [Chemical formula] (In formula (b1), R 1 is an alkyl group which may have an oxygen atom and / or a silicon atom, n is an integer of 0 or more and 5 or less, and when n is an integer of 2 or more, a plurality of R 1 may be the same or different from each other, and R b1 is a hydrogen atom or a methyl group.)

[0025] As the alkyl group which may have an oxygen atom and / or a silicon atom, an alkyl group which may be interrupted by an oxygen atom and may be substituted by an alkylsilyl group is preferable. Specifically, an alkyl group, an alkylsilyl group, an alkylsilylalkyl group, an alkylsilyloxy group, an alkylsilyloxyalkyl group, an alkoxy group and the like can be mentioned.

[0026] Examples of 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, a tert-butyl group and the like.

[0027] As the alkylsilyl group, a trialkylsilyl group is preferable. Specifically, a trimethylsilyl group and the like can be mentioned. As the alkylsilylalkyl group, a trialkylsilylalkyl group is preferable. Specifically, a trimethylsilylmethyl group, a 2-trimethylsilylethyl group, a 3-trimethylsilyl-n-propyl group and the like can be mentioned. As the alkylsilyloxy group, a trialkylsilyloxy group is preferable. Specifically, a trimethylsilyloxy group and the like can be mentioned. As the alkylsilyloxyalkyl group, a trialkylsilyloxyalkyl group is preferable. Specifically, a trimethylsilyloxymethyl group, a 2-trimethylsilyloxyethyl group, a 3-trimethylsilyloxy-n-propyl group and the like can be mentioned. Examples of 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, a tert-butoxy group and the like.

[0028] The total number of carbon atoms of the alkyl group which may be interrupted by an oxygen atom and may be substituted with an alkylsilyl group is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less, still more preferably 1 or more and 3 or less, and particularly preferably 1 or 2.

[0029] n is preferably an integer of 0 or more and 3 or less, more preferably 0 or 1, and still more preferably 0.

[0030] [Second block] The second block is composed of a random copolymer having a structure in which a structural unit represented by the following formula (b2a) (hereinafter also referred to as structural unit (b2a)) and a structural unit represented by the following formula (b2b) (hereinafter also referred to as structural unit (b2b)) are randomly arranged.

[0031] [Chemical formula] (In formula (b2a), R 2 is a group composed of three atoms selected from a carbon atom, an oxygen atom, and a sulfur atom and a hydrogen atom, and has one double bond. The three atoms may be the same as or different from each other. R 3 is a linear saturated aliphatic hydrocarbon group having 1 or more and 3 or less carbon atoms. R 4 is a single bond or an alkylene group. The total number of carbon atoms of the linear saturated aliphatic hydrocarbon group as the R 3 and the total number of carbon atoms of the single bond or the alkylene group as the R 4 is 1 or more and 10 or less. In formula (b2a) and formula (b2b), R b2is, independently of each other, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and a plurality of R b2 may be the same or different. )

[0032] (Constituent unit (b2a)) R 2 Examples of the chain saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms as R include the following groups. In addition, the group bonded to R

[0033] R 3 is also shown as a group represented by -O-R 3 (OH)-R 3 (OH)-R 4 -. -O-CH(OH)-R 4 - -O-CH2CH(OH)-R 4 - -O-CH(OH)CH2-R 4 - -O-CH2CH2CH(OH)-R 4 - -O-CH2CH(OH)CH2-R 4 - -O-CH(OH)CH2CH2-R 4 - -O-CH(CH3)CH(OH)-R 4 - -O-C(CH3)(OH)CH2-R 4 - -O-CH(CH2OH)CH2-R 4 - -O-CH2C(CH3)(OH)-R 4 - -O-CH2CH(CH2OH)-R 4 - -O-CH(OH)CH(CH3)-R 4 -

[0034] Among these groups, -O-CH(OH)-R 4 -, -O-CH2CH(OH)-R 4 -, -O-CH2CH2CH(OH)-R 4 -, -O-CH(CH3)CH(OH)-R 4 -, -O-CH2C(CH3)(OH)-R 4 - are preferred, -O-CH2CH(OH)-R 4 - is more preferred.

[0035] R 4 As the alkylene group for R, a linear or branched alkylene group is preferred, and a linear alkylene group is more preferred. R 4 As the number of carbon atoms of the alkylene group for R, 1 or more and 5 or less is preferred, 1 or more and 3 or less is more preferred, and 1 is even more preferred.

[0036] R 3 As for the number of carbon atoms of the chain-like saturated aliphatic hydrocarbon group for R, and the total of the number of carbon atoms of a single bond or an alkylene group for R 4 1 or more and 7 or less is preferred, 2 or more and 5 or less is more preferred, and 3 is even more preferred.

[0037] In formula (b2a), as the alkyl group having 1 or more and 5 or less carbon atoms for R b2 a linear or branched alkyl group having 1 or more and 5 or less carbon atoms is preferred. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, isopentyl group, sec-pentyl group, 3-pentyl group, tert-pentyl group, etc. can be mentioned. The halogenated alkyl group having 1 or more and 5 or less carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 or more and 5 or less carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferred.

[0038] In formula (b2a), R b2 is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. From the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is more preferable, and a methyl group is even more preferable.

[0039] (Constituent unit (b2b)) In formula (b2b), R b2 is the same as R b2 in formula (b2a).

[0040] In the second block, the ratio of the number of moles of the constituent unit represented by formula (b2a) to the total number of moles of the constituent unit represented by formula (b2a) and the constituent unit represented by formula (b2b) is preferably 0.90 or less, more preferably 0.30 or less, and even more preferably 0.01 to 0.10 from the viewpoint of the orientation with respect to the guide pattern.

[0041] In the block copolymer, the ratio of the volume of the first block to the total volume of the first block and the second block is 20% by volume or more and 80% by volume or less. The ratio of the volume of the first block is preferably 30% by volume or more, more preferably 35% by volume or more. Also, the ratio of the volume of the first block is preferably 70% by volume or less, more preferably 65% by volume or less, and even more preferably 60% by volume or less.

[0042] The ratio of the volume of the first block to the total volume of the first block and the second block in the block copolymer can be determined as follows. 1From the analysis results of 1H NMR, the molar percentages of the first block and the second block in the block copolymer are calculated respectively. Further, from the molecular weights of the respective blocks, the mass percentages of the respective blocks are calculated. By dividing the mass percentage of each block by the density of each block, the volume ratio of each block is calculated, and the volume percentage of the first block in the block copolymer is calculated from the volume ratio. The density of each block can be estimated by the group contribution method (Fedors, R. F. Polym. Eng. Sci. 1974, 14, 147-154.). When the first block is a polystyrene block (PS), 1.05 g / cm3 can be used as the density of PS. -3 When the second block has a structural unit derived from methyl methacrylate, 1.18 g / cm3 can be used as the density of the structure composed of the structural unit. -3 When the second block has a structural unit derived from 2-hydroxy-3-(2,2,2-trifluoroethylsulfanyl)propyl methacrylate, 1.43 g / cm3 can be used as the density of the structure composed of the structural unit. -3 Regarding the density of each block, the density described in literature such as Polymer Handbook, 4th ed.; Wiley: New York, 2004. can also be used.

[0043] In addition to the first block and the second block, the block copolymer may have other blocks. In a preferred embodiment, the block copolymer is a diblock copolymer composed of the first block and the second block.

[0044] The number average molecular weight (Mn) (polystyrene conversion standard by size exclusion chromatography) of the block copolymer is not particularly limited, but is preferably 3,000 or more and 100,000 or less, more preferably 5,000 or more and 50,000 or less, still more preferably 6,000 or more and 40,000 or less, and particularly preferably 8,000 or more and 30,000 or less. The molecular weight distribution (Mw / Mn) of each block constituting the block copolymer is preferably 1.0 or more and 1.5 or less, more preferably 1.0 or more and 1.4 or less, and still more preferably 1.0 or more and 1.3 or less.

[0045] 〔Method for producing block copolymer〕 The method for producing the block copolymer is not particularly limited, and for example, it can be produced by the same production method as the production method described in Japanese Patent No. 7213495.

[0046] <Organic solvent component> The resin composition for forming a phase separation structure preferably contains an organic solvent. The organic solvent component may be any organic solvent that can dissolve each component to be used and form a uniform solution. Conventionally, any organic solvent selected from known organic solvents as the solvent of a composition mainly composed of a resin can be used.

[0047] Examples of the organic solvent component 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, or dipropylene glycol monoacetate; monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, or monobutyl ether of the polyhydric alcohols or the monoacetates of the polyhydric alcohols, or compounds having an ether bond such as monophenyl ether, i.e., derivatives of polyhydric alcohols [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and esters other than the monoacetates of polyhydric alcohols and the derivatives of the polyhydric alcohols mentioned above, such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; and aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethyl benzene, diethyl benzene, pentyl benzene, isopropyl benzene, toluene, xylene, cymene, and mesitylene. The organic solvent component may be used alone or as a mixed solvent of two or more kinds. Among them, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, and ethyl lactate (EL) are preferred.

[0048] The organic solvent component contained in the resin composition for forming a phase separation structure is not particularly limited. The organic solvent component is appropriately set according to the coating film thickness so that the concentration of the resin composition for forming a phase separation structure is a coatable concentration. The organic solvent component is generally used so that the solid content concentration of the resin composition for forming a phase separation structure 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.

[0049] <Optional component> The resin composition for forming a phase separation structure may contain optional components other than the block copolymer and the organic solvent component described above. Examples of the optional component include other resins, surfactants, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, sensitizers, base proliferators, basic compounds, and the like.

[0050] ≪Method for manufacturing a structure including a phase separation structure≫ The method for manufacturing a structure including a phase separation structure includes a step of applying a resin composition for forming a phase separation structure on a support to form a layer containing a block copolymer (hereinafter referred to as "step (i)"), and a step of phase-separating the layer containing the block copolymer (hereinafter referred to as "step (ii)"). Hereinafter, the method for manufacturing a structure including such a phase separation structure will be specifically described with reference to FIG. 1. However, the method for manufacturing a structure including a phase separation structure according to the second aspect is not limited to the aspect specifically shown in FIG. 1.

[0051] FIG. 1 shows an example of an embodiment of a method for manufacturing a structure including a phase separation structure. In the embodiment shown in FIG. 1, first, a base agent is applied on a support 1 to form a base agent layer 2 (FIG. 1(I)). Next, a resin composition for forming a phase separation structure is applied on the base agent layer 2 to form a layer containing a block copolymer (BCP layer) 3 (FIG. 1(II); the above is step (i)). Next, heating and annealing are performed to phase-separate the BCP layer 3 into a phase 3a and a phase 3b (FIG. 1(III); step (ii)). According to the manufacturing method of such an embodiment, that is, the manufacturing method having steps (i) and (ii), a structure 3' including a phase separation structure is manufactured on a support 1 on which a base agent layer 2 is formed.

[0052] <Step (i)> In step (i), a resin composition for forming a phase separation structure is applied onto the support 1 to form a BCP layer 3. In the embodiment shown in FIG. 1, first, a base agent is applied onto the support 1 to form a base agent layer 2. By providing the base agent layer 2 on the support 1, the hydrophilic-hydrophobic balance between the surface of the support 1 and the layer containing the block copolymer (BCP layer) 3 can be achieved. That is, when the base agent layer 2 contains a resin component having a structural unit constituting the first block, the adhesion between the phase composed of the first block in the BCP layer 3 and the support 1 is enhanced. When the base agent layer 2 contains a resin component having a structural unit constituting the second block, the adhesion between the phase composed of the second block in the BCP layer 3 and the support 1 is enhanced. Along with this, due to the phase separation of the BCP layer 3, a phase separation structure oriented in the direction perpendicular to the surface of the support 1 is likely to be formed.

[0053] Base agent: As the base agent, a resin composition can be used. The resin composition for the base agent can be appropriately selected from conventionally known resin compositions used for thin film formation according to the types of blocks constituting the block copolymer. The resin composition for the base agent may be, for example, a thermopolymerizable resin composition, or a photosensitive resin composition such as a positive resist composition or a negative resist composition. Alternatively, a compound may be used as a surface treatment agent, and a non-polymerizable film formed by applying the compound may be used as the base agent layer. For example, a siloxane-based organic monomolecular film formed using phenethyltrichlorosilane, octadecyltrichlorosilane, hexamethyldisilazane, etc. as the surface treatment agent can also be suitably used as the base agent layer.

[0054] Examples of such resin compositions include resin compositions containing a resin having both the structural units constituting the first block and the second block, and resin compositions containing a resin having both structural units highly compatible with each block constituting the block copolymer, and the like. Examples of the resin composition for the undercoat include compositions containing a resin having both styrene and methyl methacrylate as structural units, and it is preferable to use a compound or composition containing both a site highly compatible with styrene such as an aromatic ring and a site highly compatible with methyl methacrylate (a highly polar functional group or the like). Examples of the resin having both styrene and methyl methacrylate as structural units include a random copolymer of styrene and methyl methacrylate, an alternating polymer of styrene and methyl methacrylate (a polymer in which each monomer is copolymerized alternately), and the like. Examples of the composition containing both a site highly compatible with styrene and a site highly compatible with methyl methacrylate include, for example, a composition containing a resin obtained by polymerizing, as monomers, at least a monomer having an aromatic ring and a monomer having a highly polar functional group. Examples of the monomer having an aromatic ring include aryl groups obtained by removing one hydrogen atom from the ring of aromatic hydrocarbons such as phenyl group, biphenyl group, fluorenyl group, naphthyl group, anthryl group, phenanthryl group, or heteroaryl groups in which a part of the carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples of the monomer having a highly polar functional group include monomers having a trimethoxysilyl group, a trichlorosilyl group, an epoxy group, a glycidyl group, a carboxy group, a hydroxy group, a cyano group, a hydroxyalkyl group in which a part of the hydrogen atoms of an alkyl group is substituted with a hydroxy group, and the like. In addition, examples of the compound containing both a site having a high affinity for styrene and a site having a high affinity for methyl methacrylate include compounds containing both an aryl group such as phenethyltrichlorosilane and a highly polar functional group, and compounds containing both an alkyl group such as an alkylsilane compound and a highly polar functional group.

[0055] The resin composition for the undercoat agent can be produced by dissolving the aforementioned resin in a solvent. Such a solvent may be any solvent that can dissolve each component to be used and form a uniform solution. For example, solvents similar to the organic solvent components exemplified in the description of the resin composition for forming a phase separation structure can be mentioned.

[0056] The type of the support 1 is not particularly limited as long as the resin composition can be coated on its surface. For example, substrates made of inorganic substances such as silicon, metals (copper, chromium, iron, aluminum, etc.), glass, titanium oxide, silica, mica; substrates made of oxides such as SiO2; substrates made of nitrides such as SiN; substrates made of oxynitrides such as SiON; substrates made of organic substances such as acrylic resins, polystyrene, cellulose, cellulose acetate, and phenolic resins can be mentioned. Among these, a silicon substrate (Si substrate) or a metal substrate is preferable, a Si substrate or a copper substrate (Cu substrate) is more preferable, and a Si substrate is particularly preferable. The size and shape of the support 1 are not particularly limited. The support 1 does not necessarily have a smooth surface, and substrates of various shapes can be appropriately selected. For example, substrates having a curved surface, flat plates with an uneven surface, and substrates in the shape of flakes can be mentioned.

[0057] An inorganic and / or organic film may be provided on the surface of the support 1. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). Examples of the organic film include an organic antireflection film (organic BARC). The inorganic film can be formed, for example, by coating an inorganic antireflection film composition such as a silicon-based material on the support and then performing firing or the like. An organic film can be formed, for example, by applying a material for forming an organic film, which is obtained by dissolving a resin component or the like constituting the film in an organic solvent, onto a substrate using a spinner or the like, and preferably baking it under heating conditions of 200°C or higher and 300°C or lower, preferably for 30 seconds or longer and 300 seconds or shorter, more preferably for 60 seconds or longer and 180 seconds or shorter. This material for forming an organic film does not necessarily require sensitivity to light or electron beams like a resist film, and may or may not have sensitivity. Specifically, resists and resins generally used in the manufacture of semiconductor elements and liquid crystal display elements can be used. Also, by etching an organic film using a pattern made of a block copolymer formed by processing the BCP layer 3, the pattern can be transferred onto the organic film to form an organic film pattern. Therefore, the material for forming an organic film is preferably a material that can form an organic film that can be etched, particularly dry-etched. Among them, it is preferably a material that can form an organic film that can be etched such as oxygen plasma etching. Such a material for forming an organic film may be a material conventionally used for forming organic films such as organic BARC. For example, the ARC series manufactured by Nissan Chemical Industries, Ltd., the AR series manufactured by Rohm and Haas, the SWK series manufactured by Tokyo Ohka Kogyo Co., Ltd., etc. can be mentioned.

[0058] The method of applying the undercoat agent onto the support 1 to form the undercoat agent layer 2 is not particularly limited and can be formed by a conventionally known method. For example, the undercoat agent can be applied onto the support 1 by a conventionally known method such as spin coating or using a spinner to form a coating film, and the undercoat agent layer 2 can be formed by drying it. As a method for drying the coating film, it is sufficient if the solvent contained in the undercoat agent can be volatilized, and examples include a baking method. At this time, the baking temperature is preferably 80°C or higher and 300°C or lower, more preferably 180°C or higher and 270°C or lower, and even more preferably 220°C or higher and 250°C or lower. The baking time is preferably 30 seconds or longer and 600 seconds or shorter, and more preferably 60 seconds or longer and 600 seconds or shorter. The thickness of the undercoat layer 2 after drying the coating film is preferably about 10 nm or more and 100 nm or less, and more preferably about 40 nm or more and 90 nm or less.

[0059] Before forming the undercoat layer 2 on the support 1, the surface of the support 1 may be washed in advance. By washing the surface of the support 1, the coatability of the undercoat agent is improved. As the cleaning treatment method, a conventionally known method can be used, and examples thereof include oxygen plasma treatment, ozone oxidation treatment, acid-base treatment, chemical modification treatment, and the like.

[0060] After forming the undercoat layer 2, if necessary, the undercoat layer 2 may be rinsed with a rinse liquid such as a solvent. By this rinsing, uncrosslinked portions and the like in the undercoat layer 2 are removed, so that the affinity with at least one block constituting the block copolymer is improved, and a phase separation structure composed of a cylinder structure oriented in the direction perpendicular to the surface of the support 1 is easily formed. The rinse liquid only needs to be able to dissolve the uncrosslinked portion, and solvents such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), ethyl lactate (EL), or a commercially available thinner liquid can be used. Further, after the cleaning, post-baking may be performed to volatilize the rinse liquid. The temperature condition of this post-baking is preferably 80°C or more and 300°C or less, and more preferably 100°C or more and 270°C or less. The baking time is preferably 30 seconds or more and 500 seconds or less, and more preferably 60 seconds or more and 240 seconds or less. The thickness of the undercoat layer 2 after such post-baking is preferably about 1 nm or more and 10 nm or less, and more preferably about 2 nm or more and 7 nm or less.

[0061] Next, a layer (BCP layer) 3 containing a block copolymer is formed on the undercoat layer 2. As a method for forming the BCP layer 3 on the underlayer 2, there is no particular limitation. For example, a method of applying the resin composition for forming a phase separation structure of the above-described embodiment on the underlayer 2 to form a coating film and drying it by a conventionally known method such as spin coating or using a spinner can be mentioned.

[0062] The thickness of the BCP layer 3 only needs to be sufficient for phase separation to occur. Considering the type of the support 1, or the structural period size of the phase separation structure to be formed or the uniformity of the nanostructures, etc., it is preferably 20 nm or more and 100 nm or less, and more preferably 30 nm or more and 80 nm or less. For example, when the support 1 is a Si substrate, the thickness of the BCP layer 3 is preferably adjusted to 10 nm or more and 100 nm or less, and more preferably 30 nm or more and 80 nm or less.

[0063] <Step (ii)> In step (ii), the BCP layer 3 formed on the support 1 is phase-separated. By heating the support 1 after step (i) and performing an annealing treatment, a phase separation structure is formed such that at least a part of the surface of the support 1 is exposed by selective removal of the block copolymer. That is, a structure 3' including a phase separation structure phase-separated into a phase 3a and a phase 3b is manufactured on the support 1. The temperature condition of the annealing treatment is preferably performed at a temperature equal to or higher than the glass transition temperature of the block copolymer used and lower than the thermal decomposition temperature. For example, when the block copolymer is a polystyrene-polymethyl methacrylate (PS-PMMA) block copolymer (weight average molecular weight of 5000 or more and 100000 or less), it is preferably 180°C or more and 270°C or less. The heating time is preferably 30 seconds or more and 3600 seconds or less. Also, the annealing treatment is preferably performed in a gas with low reactivity such as nitrogen.

[0064] <Optional step> The method for manufacturing a structure including a phase separation structure is not limited to the above-described embodiment, and may have steps (optional steps) other than steps (i) and (ii).

[0065] Examples of such arbitrary processes include a process of selectively removing a phase composed of at least one type of block among the first block and the second block constituting the block copolymer in the BCP layer 3 (hereinafter referred to as "process (iii)"), a process of forming a guide pattern, and the like.

[0066] ·Regarding process (iii) In process (iii), a phase composed of at least one type of block among the first block and the second block constituting the block copolymer in the BCP layer formed on the undercoat layer 2 is selectively removed. Thereby, a fine pattern (polymer nanostructure) is formed.

[0067] Examples of the method of selectively removing the phase composed of blocks include a method of performing oxygen plasma treatment on the BCP layer, a method of performing hydrogen plasma treatment, and the like. For example, after phase-separating the BCP layer containing the block copolymer, by performing oxygen plasma treatment, hydrogen plasma treatment, or the like on the BCP layer, the phase composed of the first block (b1) is not selectively removed, and the phase composed of the second block (b2) is selectively removed.

[0068] FIG. 2 shows an example of an embodiment of process (iii). In the embodiment shown in FIG. 2, by performing oxygen plasma treatment on the structure 3' manufactured on the support 1 in process (ii), the phase 3a is selectively removed, and a pattern (polymer nanostructure) composed of the separated phase 3b is formed. In this case, the phase 3b is the phase composed of the first block, and the phase 3a is the phase composed of the second block.

[0069] The support 1 on which a pattern is formed by phase separation of the BCP layer 3 composed of the block copolymer as described above can be used as it is, but the shape of the pattern (polymer nanostructure) on the support 1 can also be changed by further heating. The temperature condition for heating is preferably equal to or higher than the glass transition temperature of the block copolymer to be used and lower than the thermal decomposition temperature. Further, the heating is preferably carried out in a gas with low reactivity such as nitrogen.

[0070] ·Regarding the guide pattern formation step In the method for producing a structure including a phase separation structure, a step of providing a guide pattern on the underlayer agent layer (guide pattern formation step) may be provided between the above-described step (i) and step (ii). Thereby, it becomes possible to control the arrangement structure of the phase separation structure. For example, even in the case of a block copolymer in which a random fingerprint-like phase separation structure is formed when no guide pattern is provided, by providing a groove structure of a resist film on the surface of the underlayer agent layer, a phase separation structure oriented along the groove can be obtained. Based on such a principle, a guide pattern may be provided on the underlayer agent layer 2. Further, when the surface of the guide pattern has an affinity with any one of the blocks constituting the block copolymer, a phase separation structure composed of a cylinder structure oriented in a direction perpendicular to the surface of the support is likely to be formed.

[0071] 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 a resist composition generally used for forming a resist pattern and its modified products, a composition having an affinity with any one of the blocks constituting the block copolymer. As the resist composition, either a positive resist composition for forming a positive pattern in which the exposed portion of the resist film is dissolved and removed or a negative resist composition for forming a negative pattern in which the unexposed portion of the resist film is dissolved and removed may be used, but a negative resist composition is preferred. As the negative resist composition, for example, a resist composition containing an acid generator and a base material component whose solubility in a developer containing an organic solvent decreases due to the action of an acid, and the base material component contains a resin component having a structural unit that decomposes due to the action of an acid and increases in polarity is preferred. After the BCP composition is poured onto the base agent layer on which the guide pattern is formed, an annealing process is performed to cause phase separation. Therefore, as the resist composition for forming the guide pattern, a composition capable of forming a resist film excellent in solvent resistance and heat resistance is preferable. ≪Block copolymer≫ The block copolymer has a first block and a second block. The first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1). The second block is composed of a random copolymer having a structure in which the structural unit represented by the following formula (b2a) and the structural unit represented by the following formula (b2b) are randomly arranged. The ratio of the volume of the first block to the total of the volume of the first block and the volume of the second block is 20% by volume or more and 80% by volume or less.

[0072]

Chemical formula

[0073] A preferred embodiment of the block copolymer is the same as the block copolymer contained in the resin composition for forming a phase separation structure.

[0074] As described above, the present inventors provide the following (1) to (8). (1) A resin composition for forming a phase separation structure containing a block copolymer having a first block and a second block, wherein the first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1), the second block is composed of a random copolymer having a structure in which a structural unit represented by the following formula (b2a) and a structural unit represented by the following formula (b2b) are randomly arranged, and a ratio of the volume of the first block to a total of the volume of the first block and the volume of the second block is 20% by volume or more and 80% by volume or less, the resin composition for forming a phase separation structure. [Chemical formula] (In formula (b1), R 1 is an alkyl group which may have an oxygen atom and / or a silicon atom, n is an integer of 0 or more and 5 or less, and when n is an integer of 2 or more, a plurality of R 1 may be the same or different from each other, and R b1 is a hydrogen atom or a methyl group. In formula (b2a), R 2 is a group composed of three atoms selected from a carbon atom, an oxygen atom, and a sulfur atom and a hydrogen atom and having one double bond, and the three atoms may be the same or different from each other, R 3is a linear saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms, R 4 is a single bond or an alkylene group, said R 3 The sum of the number of carbon atoms of the linear saturated aliphatic hydrocarbon group as said R and the number of carbon atoms of said single bond or said alkylene group as said R 4 is 1 or more and 10 or less, In formula (b2a) and formula (b2b), R b2 is each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and a plurality of Rs b2 may be the same or different.) (2) In the second block, the ratio of the number of moles of the structural unit represented by formula (b2a) to the total number of moles of the structural unit represented by formula (b2a) and the number of moles of the structural unit represented by formula (b2b) is 0.90 or less. The resin composition for forming a phase separation structure according to (1). (3) The resin composition for forming a phase separation structure according to (2), wherein the ratio is 0.30 or less. (4) The resin composition for forming a phase separation structure according to (3), wherein the ratio is 0.01 or more and 0.10 or less. (5) The resin composition for forming a phase separation structure according to any one of (1) to (4), wherein R 2 is an allyl group, an acetyl group, or a thioacetyl group. (6) Coating the resin composition for forming a phase separation structure according to any one of (1) to (5) on a support to form a layer containing a block copolymer, Phase-separating the layer containing the block copolymer, A method for producing a structure having a phase separation structure, comprising: (7) A block copolymer having a first block and a second block, The first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1), The second block is composed of a random copolymer having a structure in which a structural unit represented by the following formula (b2a) and a structural unit represented by the following formula (b2b) are randomly arranged. A block copolymer in which the ratio of the volume of the first block to the total volume of the first block and the second block is 20% by volume or more and 80% by volume or less. [Chemical formula] (In formula (b1), R 1 is an alkyl group which may have an oxygen atom and / or a silicon atom, n is an integer of 0 or more and 5 or less, and when n is an integer of 2 or more, a plurality of R 1 may be the same or different from each other, and R b1 is a hydrogen atom or a methyl group. In formula (b2a), R 2 is a group composed of three atoms selected from a carbon atom, an oxygen atom, and a sulfur atom and a hydrogen atom, and having one double bond, and the three atoms may be the same or different from each other. R 3 is a linear saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms. R 4 is a single bond or an alkylene group. The total number of carbon atoms of the linear saturated aliphatic hydrocarbon group as the R 3 and the total number of carbon atoms of the single bond or the alkylene group as the R 4 is 1 or more and 10 or less. In formula (b2a) and formula (b2b), R b2 is each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and a plurality of R b2 may be the same or different. ) [Examples]

[0075] Based on the examples, the present invention will be described in more detail, but the present invention is not limited by these examples.

[0076] <Synthesis of BCP Precursor> [Synthesis of BCP Precursor (1)] All anionic polymerizations were carried out under an argon atmosphere. 200 mL of tetrahydrofuran (THF) and lithium chloride (LiCl) (353 mg, 8.34 mmol) were transferred to a 300 mL Schlenk tube and cooled to -78 °C in a Cool-Nexus bath. sec-Butyllithium (Sec-BuLi) (1.05 M hexane / cyclohexane solution) was added to the Schlenk tube until the color of the solution turned yellow. The Schlenk tube was removed from the Cool-Nexus bath and warmed to room temperature until the solution became colorless. The Schlenk tube was cooled again to -78 °C in the Cool-Nexus bath, and sec-BuLi (1.12 mL, 1.04 mmol) was added as an initiator. Styrene (20.0 mL, 0.174 mol) was added and stirred for 30 minutes. As a result, a bright orange solution was obtained. 1,1-Diphenylethylene (DPE) (1.07 mL, 4.71 mmol) was added, and the color of the solution changed to dark red. After stirring for 30 minutes, a monomer mixture of methyl methacrylate (MMA) (13.9 g, 0.139 mol) and glycidyl methacrylate (GMA) (4.98 g, 0.035 mol) was added and stirred for 30 minutes. The color of the solution changed from red to transparent. As a terminator, 3 mL of degassed methanol (MeOH) was added to the Schlenk tube to terminate the polymerization. The Schlenk tube was lifted out of the Cool-Nexus bath, and the solution was poured into MeOH for reprecipitation. After filtering the solid of the precipitate, vacuum drying was carried out at 40 °C to obtain a white powder of BCP precursor (1) (34.2 g, 88% yield). The Mn and dispersity (PDI = Mw / Mn) of BCP precursor (1) measured by size exclusion chromatography (SEC) were 24900 and 1.07, respectively. 11H NMR (400 MHz, CDCl3, δ, ppm): 0.85 (s, α-CH3, PMMA), 1.01 (s, α-CH3, PGMA), 1.23 - 1.69 (br, backbone, -CH2-CH-, PS), 1.74 - 2.02 (br, backbone, -CH2-CH-, PS, br, backbone, -CH2-C(CH3)-, PGMA and PMMA), 2.63 (s, -CH2-CH(CH2)-O-, PGMA), 2.84 (s, -CH2CH(CH2)-O-, PGMA), 3.21 (s, -CH2-CH(CH2)-O-, PGMA), 3.59 (s, -OCH3, PMMA), 3.79 (s, -(C=O)O-CH2-, PGMA), 4.28 (d, -(C=O)O-CH2-, PGMA), 6.39 - 6.85 (m, o-aromatic, PS) 6.91 - 7.42 (m, m-, p-aromatic, PS).

[0077] [Synthesis of BCP Precursor (2)] BCP precursor (2) was synthesized in the same manner as the synthesis of the above BCP precursor (1), except that the amount of styrene used was 26.6 mL (0.232 mol), the amount of MMA used was 11.3 g (0.112 mol), and the amount of GMA used was 0.75 g (5.30 mmol). The Mn and dispersity (PDI = Mw / Mn) of BCP precursor (2) measured by size exclusion chromatography (SEC) were 26200 and 1.06, respectively.

[0078] [Synthesis of BCP Precursor (3)] BCP precursor (3) was synthesized in the same manner as the synthesis of the above BCP precursor (1), except that the amount of styrene used was 26.6 mL (0.232 mol), the amount of MMA used was 10.5 g (0.105 mol), and the amount of GMA used was 1.75 g (12.3 mmol). The Mn and dispersity (PDI = Mw / Mn) of BCP precursor (3) measured by size exclusion chromatography (SEC) were 25900 and 1.06, respectively.

[0079] [Synthesis of BCP Precursor (4)] The BCP precursor (4) was synthesized in the same manner as the synthesis of the above BCP precursor (1), except that the amount of styrene used was 26.6 mL (0.232 mol), the amount of MMA used was 10.2 g (0.102 mol), and the amount of GMA used was 2.33 g (16.4 mmol). The Mn and dispersity (PDI = Mw / Mn) of the BCP precursor (4) measured by size exclusion chromatography (SEC) were 25,800 and 1.06, respectively.

[0080] <Synthesis of Block Copolymer> [Synthesis of BCP (A1)] 10 g of the BCP precursor (1) and THF (10 wt% solution) were placed in a 200 mL glass tube and immersed in an ice water bath. A 1 wt% aqueous lithium hydroxide (LiOH) solution (LiOH 0.05 molar equivalent / GMA unit) and 2,2,2-trifluoroethanethiol (2 molar equivalents / GMA unit) were added to the glass tube. After stirring at room temperature for 20 minutes, the reactor was set to 40 °C and stirred for 3 hours to synthesize BCP (A1). Depending on the Mn and PHFMA fraction of the synthesized BCP (A1), precipitation was repeated several times with methanol or methanol / hexane to remove residual reagents. The product was dried under reduced pressure at room temperature overnight to obtain a white powder of BCP (A1). The Mn and dispersity (PDI = Mw / Mn) of BCP (A1) measured by size exclusion chromatography (SEC) were 26,500 and 1.06, respectively. 11H NMR (400 MHz, Acetone-d6, δ, ppm): 0.84 (s, α-CH3, PMMA), 0.87 (s, α-CH3, PMMA), 1.00 (s, α-CH3, PMMA), 1.03 (s, α-CH3, PGMA), 1.23 - 1.73 (br, backbone, -CH2-CH-, PS), 1.75 - 2.23 (br, backbone, -CH2-CH-, PS, br, backbone, -CH2-C(CH3)-, PGMA and PMMA), 2.78 - 3.00 (d, CH(OH)-CH2-S-, PHFMA), 3.40 - 3.77 (s, -S-CH2-CF3, PHFMA), 3.54 - 3.75 (s, -OCH3, PMMA), 3.92 - 4.07 (d, -(C=O)O-CH2-, PHFMA), 4.07 - 4.18 (m, -CH(OH)-, PHFMA) 4.50 - 4.72 (br, -CH(OH)-, PHFMA), 6.36 - 6.84 (m, o-aromatic, PS), 6.85 - 7.35 (m, m-, p-aromatic, PS).

[0081]

Chem.

[0082] 〔Synthesis of BCP (B1)〕 BCP (B1) was synthesized in the same manner as the synthesis of BCP-A1, except that thioacetic acid was used instead of 2,2,2-trifluoroethanethiol. The Mn and dispersity (PDI = Mw / Mn) of BCP (B1) measured by size exclusion chromatography (SEC) were 26500 and 1.06, respectively.

[0083] 〔Synthesis of BCP (B2) - BCP (B4)〕 BCP (B2) - BCP (B4) were synthesized in the same manner as the synthesis of BCP (B1), except that BCP precursors (2) - (4) were used instead of BCP precursor (1). The Mn and dispersity (PDI = Mw / Mn) of BCP (B2) measured by size exclusion chromatography (SEC) were 26500 and 1.06, respectively. The Mn and dispersity (PDI = Mw / Mn) of BCP (B3) measured by size exclusion chromatography (SEC) were 26,500 and 1.06, respectively. The Mn and dispersity (PDI = Mw / Mn) of BCP (B4) measured by size exclusion chromatography (SEC) were 26,500 and 1.06, respectively.

[0084] [Chemical formula]

[0085] [Synthesis of BCP (C1)] BCP (C1) was synthesized in the same manner as the synthesis of BCP (A1), except that 2-propen-1-thiol was used instead of 2,2,2-trifluoroethanethiol. The Mn and dispersity (PDI = Mw / Mn) of BCP (C1) measured by size exclusion chromatography (SEC) were 26,500 and 1.06, respectively.

[0086] [Synthesis of BCP (C2) and BCP (C3)] BCP (C2) and BCP (C3) were synthesized in the same manner as the synthesis of BCP (C1), except that BCP precursor (2) and BCP precursor (3) were used instead of BCP precursor (1), respectively. The Mn and dispersity (PDI = Mw / Mn) of BCP (C2) measured by size exclusion chromatography (SEC) were 26,500 and 1.06, respectively. The Mn and dispersity (PDI = Mw / Mn) of BCP (C3) measured by size exclusion chromatography (SEC) were 26,500 and 1.06, respectively.

[0087] [Chemical formula]

[0088] [Measurement of the volume of each block] The mole % of each block in the block copolymer 1Calculated from the results of 1H NMR analysis, and further, the mass % of each block was calculated. Next, the volume ratio of each block was calculated by dividing the mass % of each block by the density of each block. From the said volume ratio, the ratio of the volume of the polystyrene block to the total volume of the block copolymer was calculated. The density of each block was estimated by the group contribution method (Fedors, R. F. Polym. Eng. Sci. 1974, 14, 147 - 154.). Note that as the density of the polystyrene block, 1.05 g / cm -3 was used. As the density of the structure composed of the structural units derived from methyl methacrylate, 1.18 g / cm -3 was used. As the density of the structure composed of the structural units derived from 2 - hydroxy - 3 - (2,2,2 - trifluoroethylsulfanyl)propyl methacrylate, 1.43 g / cm -3 was used (BCP(A1)). In BCP(B1) - BCP(B4) and BCP(C1) - BCP(C3), as the density of the structure composed of the structural units corresponding to the structural unit (b2a), all 1.18 g / cm -3 was used.

[0089] The number - average molecular weight (Mn) of each block copolymer synthesized above and the ratio (volume %) of the volume of the polystyrene block (PS) to the total volume of the block copolymer are summarized in Table 1. Also, the ratios (x:y:z) of the number of moles of the structural unit (b1), the number of moles of the structural unit (b2a), and the number of moles of the structural unit (b2b) to the total number of moles of each structural unit of each block copolymer synthesized above, and the ratio (y / (y + z)) of the number of moles of the structural unit (b2a) to the total number of moles of the structural unit (b2a) and the structural unit (b2b) are summarized in Table 2.

[0090]

Table 1

[0091] <Preparation of a resin composition for forming a phase - separation structure and production of a structure including the phase - separation structure> Each BCP shown in Table 2 was mixed and dissolved with propylene glycol monomethyl ether acetate to prepare a resin composition for forming a phase separation structure (solid content concentration: 0.8% by mass) for each example.

[0092] After forming a guide pattern with the resist composition, using the resin composition for forming a phase separation structure of each of the above examples, a structure including a phase separation structure was obtained by a manufacturing method having the following steps (i) and (ii).

[0093] Formation of guide pattern The organic antireflection film composition "ARC-29A" (trade name, manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and baked on a hot plate at 205 °C for 60 seconds to dry, thereby forming an organic antireflection film with a film thickness of 89 nm. After spin-coating a neutral film composition solution (underlayer agent) on the organic antireflection film, it was heated at 250 °C for 600 seconds. As a result, a thin film with a film thickness of 60 nm made of the neutral film composition was formed on the surface of the substrate. Next, the underlayer agent layer was rinsed with OK73 thinner (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 15 seconds to remove random copolymers such as uncrosslinked portions. After that, it was baked at 100 °C for 60 seconds. A resist film for forming a guide pattern was applied onto the film using a spinner, and prebaked (PAB) on a hot plate and dried, thereby forming a resist film for forming a guide pattern with a film thickness of 90 nm. An ArF excimer laser (193 nm) was selectively irradiated through a mask pattern by an ArF exposure apparatus XT-1900Gi (manufactured by ASML). Then, post-exposure bake (PEB) treatment was performed, followed by development with butyl acetate and spin-drying. Next, post-bake treatment was performed under the conditions of 100 °C for 1 minute and then 200 °C for 5 minutes to form a guide pattern adjusted to a space dimension 4 times the d value of the block copolymer to be used.

[0094] As the neutral film composition solution, the following NL-1 or NL-2 was used. NL-1: A PGMEA solution (copolymer concentration: 2.0% by mass) of a copolymer having styrene (St) units, methyl methacrylate (MMA) units, and 2-hydroxyethyl methacrylate (HEMA) units (St / MMA / HEMA = 49 / 46 / 5 (mol %), number average molecular weight 28,000) NL-2: A PGMEA solution (copolymer concentration: 2.0% by mass) of a copolymer having styrene (St) units, methyl methacrylate (MMA) units, and 2-hydroxyethyl methacrylate (HEMA) units (St / MMA / HEMA = 70 / 25 / 5 (mol %), number average molecular weight 29,000)

[0095] Step (i): On the undercoat layer, the resin composition of each example was spin-coated so that the film thickness became 30 nm, and a resin composition layer (layer containing a block copolymer) was formed.

[0096] Step (ii): The resin composition layer formed on the undercoat layer was pre-baked at 90 °C for 60 seconds in a nitrogen atmosphere, and then annealed at 220 °C for 30 minutes in a nitrogen atmosphere to form a phase-separated structure.

[0097] Step (iii): For the substrate on which the phase-separated structure was formed, oxygen plasma treatment (200 mL / min, 40 Pa, 40 °C, 200 W, 10 seconds) was performed using TCA-3822 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), and the phase composed of PMMA was selectively removed.

[0098] (Evaluation of vertical alignment) The surface (phase-separated state) of the obtained substrate was observed with a length-measuring SEM (scanning electron microscope, trade name: CG6300, manufactured by Hitachi High-Technologies Corporation). As a result of such observation, based on the following evaluation criteria, the phase-separation performance was evaluated. The results are shown in Table 2 as "phase vertical alignment". A: Vertical alignment was observed over the entire surface B: Vertical alignment was not partially observed

[0099] (Evaluation of the guide array) The surface of the obtained substrate (phase separation state) was observed with a length-measuring SEM (scanning electron microscope, trade name: CG6300, manufactured by Hitachi High-Technologies Corporation). As a result of such observation, the guide array was evaluated based on the following evaluation criteria. The results are shown in Table 2 as "guide array". A: A phase separation structure is formed over the entire surface of the substrate on which the guide pattern is formed B: A phase separation structure is not formed in a part of the substrate on which the guide pattern is formed

[0100] [Table 2]

[0101] As shown in Tables 1 and 2, it was confirmed that in Examples 1 to 7 containing a predetermined block copolymer, a phase separation structure with good vertical alignment could be formed. In particular, in Examples 3 to 6 where the molar ratio of the constitutional unit (b2a) is 0.10 or less, it was also confirmed that in addition to the vertical alignment, the alignment with respect to the guide pattern is good.

Claims

1. A resin composition for forming a phase separation structure, containing a block copolymer having a first block and a second block, wherein the first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1), the second block is composed of a random copolymer having a structure in which the structural unit represented by the following formula (b2a) and the structural unit represented by the following formula (b2b) are randomly arranged, and a ratio of a volume of the first block to a total of the volume of the first block and the volume of the second block is 20% by volume or more and 80% by volume or less. The resin composition for forming a phase separation structure. 【Chemical 1】 (In formula (b1), R １ is an alkyl group which may have an oxygen atom and / or a silicon atom, n is an integer of 0 or more and 5 or less, and when n is an integer of 2 or more, a plurality of R １ may be the same or different from each other, and R ｂ１ is a hydrogen atom or a methyl group.) In formula (b2a), R ２ is a group composed of three atoms selected from a carbon atom, an oxygen atom, and a sulfur atom and a hydrogen atom, and having one double bond, and the three atoms may be the same as or different from each other. R ３ is a linear saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms, R ４ is a single bond or an alkylene group, Said R ３ The number of carbon atoms of the chain-like saturated aliphatic hydrocarbon group as said R, and said R ４ The sum of the number of carbon atoms of the single bond or the alkylene group as said R is 1 or more and 10 or less, In formula (b2a) and formula (b2b), R ｂ２ is, independently of each other, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and a plurality of R ｂ２ may be the same or different. )

2. In the second block, a ratio of a number of moles of the structural unit represented by the formula (b2a) to a total of the number of moles of the structural unit represented by the formula (b2a) and the number of moles of the structural unit represented by the formula (b2b) is 0.90 or less. The resin composition for forming a phase separation structure according to Claim 1.

3. The resin composition for forming a phase separation structure according to Claim 2, wherein the ratio is 0.30 or less.

4. The resin composition for forming a phase separation structure according to Claim 3, wherein the ratio is 0.01 or more and 0.10 or less.

5. The aforementioned R ２ The resin composition for forming a phase separation structure according to claim 1, wherein R is an allyl group, an acetyl group, or a thioacetyl group.

6. Applying the resin composition for forming a phase separation structure according to any one of Claims 1 to 5 onto a support to form a layer containing the block copolymer, and phase-separating the layer containing the block copolymer. The method for manufacturing a structure having a phase separation structure, including these steps.

7. A block copolymer having a first block and a second block, wherein the first block is composed of a polymer having a repeating structure of a structural unit represented by the following formula (b1), the second block is composed of a random copolymer having a structure in which the structural unit represented by the following formula (b2a) and the structural unit represented by the following formula (b2b) are randomly arranged, and a ratio of a volume of the first block to a total of the volume of the first block and the volume of the second block is 20% by volume or more and 80% by volume or less. The block copolymer. ​ [Chemical Formula 2] (In formula (b1), R １ is an alkyl group which may have an oxygen atom and / or a silicon atom, n is an integer of 0 or more and 5 or less, and when n is an integer of 2 or more, a plurality of R １ may be the same or different from each other, and R ｂ１ is a hydrogen atom or a methyl group.) In formula (b2a), R ２ is a group composed of three atoms selected from a carbon atom, an oxygen atom, and a sulfur atom and a hydrogen atom, and having one double bond, and the three atoms may be the same as or different from each other. R ３ is a straight-chain saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms, R ４ is a single bond or an alkylene group, Said R ３ The number of carbon atoms of the chain-like saturated aliphatic hydrocarbon group as said R, and said R ４ The sum of the number of carbon atoms of the single bond or the alkylene group as said R is 1 or more and 10 or less, In formula (b2a) and formula (b2b), R ｂ２ is, independently of one another, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and a plurality of R ｂ２ may be the same or different. )

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