JP7800317B2 - Polymer material, method for manufacturing polymer material, self-assembled film, method for manufacturing self-assembled film, pattern, and method for forming pattern - Google Patents

Description

The present invention relates to polymeric materials, methods for manufacturing polymeric materials, self-assembled films, methods for manufacturing self-assembled films, patterns, and methods for forming patterns.

As semiconductors and other electronic components become smaller, demand for lithography technology, which can form fine patterns, is increasing.

In particular, technology using directed self-assembly (DSA), which utilizes microphase separation of block copolymers, is attracting attention as a next-generation lithography technology because it enables the formation of fine patterns at low cost.

As an example of such technology, Patent Document 1 discloses a polymer film in which a block copolymer resin composed of at least two or more types of mutually incompatible polymers bonded at their ends is placed on a substrate having a surface roughness of at least 1 nm, resulting in a block copolymer film having a microdomain structure oriented perpendicular to the substrate surface, and the block copolymer resin is a mixture of at least two or more types of block copolymer resins with different molecular weights.

Japanese Patent Application Laid-Open No. 2005-8701

The inventors have examined conventional induced self-assembly materials and found that when the half pitch (hp) of the pattern to be formed is small and uniform and a composition (polymer block configuration or weight average molecular weight) that can form an induced self-assembly film (also simply referred to as a self-assembly film) that has film strength is used, there is a problem in that the etching resistance during dry etching decreases.
In other words, conventional guided self-assembly materials have not been able to form patterns with small and uniform half pitches (hp), have film strength, and exhibit excellent etching resistance during dry etching, and there is still room for further improvement.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a polymeric material capable of forming a self-assembled film that has a small and uniform half pitch (hp) of the formed pattern, has film strength, and exhibits excellent etching resistance during dry etching.

The inventors conducted extensive research into the above-mentioned problems and discovered that a multiblock copolymer formed by linking a first polymer block containing a structural unit represented by the general formula (1) described below with a second polymer block containing a structural unit represented by the general formula (3) described below and/or a structural unit derived from a (meth)acrylic acid alkyl ester can form a pattern with a small and uniform half pitch (hp) and can also impart film strength. They also discovered that etching resistance can be improved, leading to the present invention.

That is, the present invention provides: a polymeric material containing a multiblock copolymer formed by linking a first polymer block containing a structural unit represented by the following general formula (1) with a second polymer block containing a structural unit represented by the following general formula (3) and/or a structural unit derived from a (meth)acrylic acid alkyl ester; a method for producing a polymeric material, the method comprising the step of producing a multiblock copolymer formed by linking a first polymer block containing a structural unit represented by the following general formula (1) with a second polymer block containing a structural unit represented by the following general formula (3) and/or a structural unit derived from a (meth)acrylic acid alkyl ester; a self-assembled monolayer obtained using the polymeric material; a method for producing a self-assembled monolayer using the polymeric material; a pattern formed by etching the self-assembled monolayer; and a method for forming a pattern, the method comprising the step of etching the self-assembled monolayer to form a pattern.

[In general formula (1), ^R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, a represents an integer of 1 or more and 1,000 or less, and X represents a substituent represented by general formula (2)]
[In general formula (2), b is an integer of 1 or more and 5 or less.]
[In general formula (3), ^R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and c represents an integer of 1 to 1,000.]

The present invention provides a polymeric material capable of forming a self-assembled film that has a small and uniform half pitch (hp) of the formed pattern, has film strength, and exhibits excellent etching resistance during dry etching.

<Polymer materials>
The polymer material of the present invention contains a multiblock copolymer in which a first polymer block containing a constitutional unit represented by the following general formula (1) and a second polymer block containing a constitutional unit represented by the following general formula (3) and/or a constitutional unit derived from an alkyl (meth)acrylate are linked together:

[In general formula (1), ^R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, a represents an integer of 1 or more and 1,000 or less, and X represents a substituent represented by general formula (2)]
[In general formula (2), b is an integer of 1 or more and 5 or less.]
[In general formula (3), ^R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and c represents an integer of 1 to 1,000.]

The directed self-assembly (DSA) technique utilizes the ability to form microphase separation, which occurs when two types of polymer chains that are incompatible with each other are linked at one point by copolymerization.
In multiblock copolymers linked by covalent bonds, when identical polymer components aggregate together and undergo microphase separation, the interfacial curvature during molecular aggregation changes depending on the volume fraction ratio (f) between the two polymer components, resulting in a change in the microdomain structure.

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

(First polymer block)
The first polymer block contains a constitutional unit represented by the above general formula (1).

R ¹ in the above general formula (1) is not particularly limited as long as it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group.
Among these, R ¹ is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, from the viewpoint of being able to reduce defects due to poor microphase separation sites and to form fine and minute repeated patterns.

In the above general formula (2), b is an integer of 1 or more and 5 or less.
From the viewpoint of reducing the half pitch (hp), b is preferably 1 or 2, and more preferably 1.

The first polymer block may contain a structural unit other than the structural unit represented by the general formula (1) above.
Examples of structural units other than the structural unit represented by the general formula (1) include structural units represented by the following general formula (4).

[In general formula (4), ^R3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and d represents an integer of 1 to 1,000.]

^R3 in the general formula (4) is not particularly limited as long as it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and the substituents exemplified for ^R1 above can be applied.
Among these, ^R3 is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, from the viewpoint of being able to reduce defects due to poor microphase separation sites and to form fine and minute repeated patterns.

The first polymer block can be, for example, a first polymer block A consisting of a structural unit represented by the above general formula (1), or a first polymer block B formed by repeated random polymerization of a structural unit represented by the above general formula (1) and a structural unit different from the above general formula (1) (for example, a structural unit represented by the above general formula (4)).

The first polymer block preferably contains 90 mol % or more of the constitutional unit represented by the general formula (1) above, and more preferably contains 100 mol % of the constitutional unit represented by the general formula (1) above, based on the entire first polymer block.
By including the constitutional unit represented by the general formula (1) in the above proportion relative to the entire first polymer block, it is possible to impart favorable film strength and etching resistance.

(Second Polymer Block)
The second polymer block contains a structural unit represented by the above general formula (3) and/or a structural unit derived from an alkyl (meth)acrylate ester.

^R2 in the general formula (3) is not particularly limited as long as it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and the substituents exemplified for ^R1 above can be applied.
Among these, ^R2 is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, from the viewpoint of being able to reduce defects due to poor microphase separation sites and to form fine and minute repeated patterns.

Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, 2-methylpentyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and cyclohexyl (meth)acrylate.
Among these, methyl methacrylate is preferred from the viewpoint of providing suitable etching resistance.
In this specification, (meth)acrylic acid means acrylic acid and methacrylic acid.

The second polymer block can be, for example, a second polymer block C formed by repeatedly polymerizing the same structural unit represented by the general formula (3) above, a second polymer block D formed by repeatedly polymerizing a structural unit derived from the (meth)acrylic acid alkyl ester, or a second polymer block E formed by randomly polymerizing a structural unit represented by the general formula (3) above and a structural unit derived from the (meth)acrylic acid alkyl ester.

In the second polymer block E, the molar ratio of the structural unit represented by the above general formula (3) to the structural unit derived from the (meth)acrylic acid alkyl ester is preferably within the range of 9:1 to 1:9.

(multiblock copolymer)
The multiblock copolymer is formed by linking the first polymer block and the second polymer block described above.

The multiblock copolymer is preferably a diblock copolymer or higher.

As the diblock copolymer, a copolymer in which the above-mentioned first polymer blocks A and B and second polymer blocks C, D, and E are arranged in any order, such as AC, AD, AE, BC, BD, or BE, can be used.
From the viewpoint of being able to reduce defects due to sites of poor microphase separation and being able to form fine and minute repeating patterns, a polymerizable composition (AC) in which a first polymerized block A formed by repeatedly polymerizing the same structural unit represented by the general formula (1) and a second polymerized block C formed by repeatedly polymerizing the same structural unit represented by the general formula (3) are arranged is preferred.

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

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

In terms of the ratio of the constituent units of the multiblock copolymer, from the viewpoint of improving the uniformity and regularity of the pattern of the microdomain structure formed by self-assembly, it is preferable that the molar ratio of the first polymer block to the second polymer block (moles of the first polymer block:moles of the second polymer block) be within the range of 8:2 to 2:8.

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

The multiblock copolymer preferably has a number average molecular weight (Mn) of 3,000 or more and 50,000 or less, from the viewpoint of improving the uniformity and regularity of the pattern of the microdomain structure formed by self-organization.
When the number-average molecular weight (Mn) is 3,000 or more, self-assembly proceeds to form a self-assembled film having a microdomain structure. When the number-average molecular weight (Mn) is 50,000 or less, hydrogen bonds possessed by the hydrophilic groups of the polymer compound function appropriately, making it easy to achieve a pattern size of 10.0 nm or less.
The number average molecular weight (Mn) is more preferably 5,000 or more, and even more preferably 6,000 or more, and more preferably 20,000 or less.

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

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

The composition ratio of the multiblock copolymer can be determined by nuclear magnetic resonance (NMR) spectroscopy.
The composition ratio by the NMR method can be measured, for example, under the conditions of an NMR measurement device (trade name "JNM-ECZ400R", manufactured by JEOL, analysis software: Delta5.3.1, frequency: 400 MHz), temperature: 25°C, solvent (CDCl ₃ ), internal standard: tetramethylsilane (TMS), and accumulation number: 16.
The composition of the multiblock copolymer means the constituent units that make up the multiblock copolymer, and the composition ratio means the molar ratio of the constituent units that make up the multiblock copolymer.

The method for producing a polymer material of the present invention includes a step of producing a multiblock copolymer in which a first polymerization block containing a constitutional unit represented by the above general formula (1) and a second polymerization block containing a constitutional unit represented by the above general formula (3) and/or a constitutional unit derived from a (meth)acrylic acid alkyl ester are linked together.
In a method for producing a multiblock copolymer, for example, 4-(1-ethoxyethoxy)styrene protected with a protecting group is reacted with a monomer that forms a second polymer block by living anionic polymerization to synthesize the multiblock copolymer.
The substituent is not particularly limited, and a t-butyl group, a trialkylsilyl group, etc. can be used.
Next, after deprotection, the 4-(1-ethoxyethoxy)styrene moiety is converted to hydroxystyrene by acidolysis, which can be carried out using a known acid or solvent.
Thereafter, the hydroxyl group of the hydroxystyrene is substituted with a sodium oxide group (or a potassium oxide group, etc.) to obtain a constitutional unit represented by the following general formula (5) (also referred to as the first-stage addition reaction).
Finally, the sodium oxide group in the constitutional unit represented by the following general formula (5) is substituted with siloxane to produce the constitutional unit represented by the above general formula (1) (first polymer block) (this is also referred to as the second-stage addition reaction).
The method for substituting the hydroxyl group in the first-stage addition reaction with a sodium oxide group or the like and the method for substituting the sodium oxide group in the second-stage addition reaction with a siloxane are not particularly limited, and known methods can be used.

[In general formula (5), ^R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a represents an integer of 1 to 1,000.]

The multi-block copolymer is preferably copolymerized by living anionic polymerization.
A multiblock copolymer of a first polymer block mainly composed of a structural unit represented by the general formula (1) copolymerized by living anionic polymerization and a second polymer block mainly composed of a structural unit represented by the general formula (3) is preferred.
By copolymerizing polymer materials by living anionic polymerization, it is possible to narrow the PDI and precisely obtain polymer compounds with desired number-average molecular weights, thereby improving the uniformity and regularity of the microdomain structure patterns formed by self-organization.

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

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

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

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

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

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

Examples of alkyl lactate esters include those in which the alkyl group has 1 to 4 carbon atoms. Examples of such alkyl groups include methyl, ethyl, propyl, and butyl groups. Of these, methyl and ethyl groups are preferred.

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

There are no particular restrictions on the concentration of the solution in which the polymer material of the present invention is dissolved in an organic solvent, as long as it allows a self-assembled film to be obtained using a conventionally known film-forming method. For example, the organic solvent is preferably 5,000 to 50,000 parts by weight, and more preferably 7,000 to 30,000 parts by weight, per 100 parts by weight of the solid content of the polymer material.

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

The self-assembled film of the present invention is preferably coated with a top coating agent on its surface, as this seals and protects the self-assembled film, improving the handling and weather resistance of the self-assembled film.

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

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

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

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

In TEM observation, the sample film is first cut to an appropriate size and placed in an embedding mold, then epoxy resin is poured into it and the mold is left to stand at 60°C for 12 hours to harden the epoxy resin and embed the film. The embedded sample film is then cut into sections approximately 50 nm thick using a microtome, and the sections are then collected on Cu grids _, stained with _Cs2CO3 , and observed with a transmission electron microscope to measure the hp.

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

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

This specification discloses the following:

The present disclosure (1) relates to a polymer material containing a multiblock copolymer formed by linking a first polymer block containing a structural unit represented by the above general formula (1) with a second polymer block containing a structural unit represented by the above general formula (3) and/or a structural unit derived from a (meth)acrylic acid alkyl ester.

Disclosure (2) is the polymer material described in Disclosure (1), in which the multiblock copolymer is a diblock copolymer or greater and a hexablock copolymer or less.

Disclosure (3) is a polymer material according to disclosure (1) or (2), in which the multiblock copolymer is copolymerized by living anionic polymerization.

Disclosure (4) is a polymer material according to any one of disclosures (1) to (3), wherein the multiblock copolymer has a number average molecular weight of 3,000 or more and 50,000 or less.

The present disclosure (5) relates to a method for producing a polymeric material, comprising the step of producing a multiblock copolymer in which a first polymer block containing a structural unit represented by the above general formula (1) is linked to a second polymer block containing a structural unit represented by the above general formula (3) and/or a structural unit derived from a (meth)acrylic acid alkyl ester.

The present disclosure (6) is a self-assembled monolayer obtained using the polymer material described in any one of the present disclosures (1) to (4).

The present disclosure (7) is a self-assembled monolayer described in the present disclosure (6) having a top coating agent applied to the surface.

The present disclosure (8) is a method for producing a self-assembled film, which forms a self-assembled film using a polymer material described in any one of the present disclosures (1) to (4).

The present disclosure (9) is a method for producing a self-assembled film according to the present disclosure (8), which forms a self-assembled film within a guide pattern.

The present disclosure (10) is a method for producing a self-assembled film according to the present disclosure (8) or (9), which includes a step of applying a top coating agent onto the self-assembled film.

The present disclosure (11) is a pattern obtained by etching the self-assembled film described in the present disclosure (6) or (7).

The present disclosure (12) is a pattern formation method including a step of etching the self-assembled film described in the present disclosure (6) or (7) to form a pattern.

Below, we will explain examples and comparative examples conducted to clarify the effects of the present invention. Note that the present invention is not limited in any way by the following examples and comparative examples.

Example 1: Synthesis of diblock copolymer (BP-3)
A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4,500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 8.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 81.0 g of 4-(1-ethoxyethoxy)styrene that had been subjected to distillation and purification treatment was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes (formation of a first polymer block precursor).
Next, 48.0 g of styrene that had been subjected to a distillation dehydration treatment was added dropwise and reacted for 30 minutes (formation of a second polymer block precursor).
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 130 g of a diblock copolymer (BP-1).

Next, 50 g of the obtained diblock copolymer (BP-1) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
Next, the resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. Next, the deprotected diblock copolymer solution was added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-2).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of diblock copolymer (BP-2).

Next, 38 g of the obtained diblock copolymer (BP-2) was dissolved in 100 g of THF and the solution was poured into a glass reactor equipped with a heating and stirring device and a cooling device, and then 0.4 g of potassium t-butoxide was added. After nitrogen substitution, stirring was started and the temperature was raised to 130°C, followed by stirring at the same temperature for 8 hours (first-stage addition reaction).
Next, 29.6 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was successively added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction).The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 62 g of the target diblock copolymer (BP-3).

<Measurement of number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution (PDI) of diblock copolymer (BP-3)>
The number average molecular weight and molecular weight distribution of the obtained diblock copolymer (BP-3) were measured by gel permeation chromatography (GPC) under the following measurement conditions. The measurement results are shown below and in Table 2.
GPC measuring device: trade name: "HLC-8120", manufactured by Tosoh Corporation; Column: trade name: "TSK GEL GMH6", manufactured by Tosoh Corporation
Mobile phase: THF
Column temperature: 40°C
Standard material: polystyrene

GPC measurement using standard polystyrene as the standard revealed that the Mn of the resulting diblock copolymer (BP-3) was 10,032, the Mw was 10,835, and the PDI was 1.08.

<Measurement of composition ratio of diblock copolymer (BP-3)>
The composition ratio of the obtained diblock copolymer (BP-3) was measured by nuclear magnetic resonance (NMR) spectroscopy ( ¹ H-NMR) under the following measurement conditions.
NMR measurement device: trade name "JNM-ECZ400R, manufactured by JEOL Ltd., analysis software: Delta 5.3.1"
Frequency: 400MHz
Temperature: 25℃
Solvent: CDCl3
Internal standard: tetramethylsilane (TMS)
Number of times accumulated: 16

The area ratio of each signal revealed that the composition ratio (molar ratio) of the diblock copolymer (BP-3) was first polymer block:second polymer block = 48:52.

In the SAXS measurement, the block copolymer powder was heat-treated on a heat-resistant film, and microphase separation in the bulk state was measured using a small-angle X-ray scattering (SAXS) analyzer (ultrafine periodic structure analysis system: trade name "Nano-Viewer AXIS IV", manufactured by Rigaku Corporation).
X-rays were incident on a sample film of diblock copolymer (BP-3), and the angular dependence of scattering on the small-angle side was measured for 60 minutes using an imaging plate. The measurement data was processed by calculating q/nm ^-1 after background correction for air scattering and other factors. After Fourier transform analysis, the half pitch (hp) of the self-assembled monolayer, which is half the identity period (d) of the average repeat pattern size width of the microdomain structure formed by self-assembly of the block copolymer, was measured.
As a result, the identity period (d) was 18.0 nm and the half pitch (hp) was 9.0 nm. The measurement results are shown in Table 2 below.

Example 2: Synthesis of tetrablock copolymer (BP-6)
A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4,500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 8.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 40.5 g of 4-(1-ethoxyethoxy)styrene that had been subjected to distillation and purification treatment was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition, the reaction was continued for an additional 30 minutes (formation of a first polymer block A precursor). Next, 24.0 g of styrene that had been subjected to distillation and dehydration treatment was added dropwise and the reaction was continued for an additional 30 minutes (formation of a second polymer block A precursor).
Next, 40.5 g of 4-(1-ethoxyethoxy)styrene that had been further dehydrated by distillation was added dropwise, and after completion of the dropwise addition, the reaction was continued for an additional 30 minutes (forming a first polymer block B precursor). Next, 24.0 g of styrene that had been further dehydrated by distillation was added dropwise, and the reaction was continued for 30 minutes (forming a second polymer block B precursor). Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 130 g of tetrablock copolymer (BP-4).

Next, 50 g of the obtained tetrablock copolymer (BP-4) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
The resulting reaction solution was then concentrated under reduced pressure, and 100 g of THF and 100 g of acetone were added to redissolve the deprotected tetrablock copolymer. The deprotected tetrablock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the tetrablock copolymer (BP-5).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of the tetrablock copolymer (BP-5).

Next, 38 g of the obtained tetrablock copolymer (BP-5) was dissolved in 100 g of THF and the solution was poured into a glass reactor equipped with a heating and stirring device and a cooling device, and then 0.4 g of potassium t-butoxide was added. After nitrogen substitution, stirring was started and the temperature was raised to 130°C, followed by stirring at the same temperature for 8 hours (first-stage addition reaction).
Next, 29.6 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was successively added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction).The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 62 g of the target tetrablock copolymer (BP-6).

The resulting tetrablock copolymer (BP-6) was used to measure the composition ratio (molar ratio), Mn, Mw, and PDI of the tetrablock copolymer (BP-6) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2.
First polymer block (A+B): Second polymer block (A+B)=48:52
Mn = 9983
Mw = 10681
PDI = 1.07

Next, the identity period (d) and hp of the pattern created using the above-mentioned method were measured. As a result, the identity period (d) was 9.0 nm and hp was 4.5 nm. The measurement results are shown in Table 2 below.

Example 3: Synthesis of hexablock copolymer (BP-9)
A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4,500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 8.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 27.0 g of 4-(1-ethoxyethoxy)styrene that had been purified by distillation was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition, the reaction was continued for an additional 30 minutes (forming a first polymer block A precursor). Next, 16.0 g of styrene that had been subjected to distillation and dehydration treatment was added dropwise and the reaction was continued for an additional 30 minutes (forming a second polymer block A precursor).
Next, 27.0 g of 4-(1-ethoxyethoxy)styrene that had been further subjected to distillation and dehydration treatment was added dropwise, and after completion of the dropwise addition, the mixture was allowed to react for an additional 30 minutes (forming a precursor of the first polymer block B). Next, 16.0 g of styrene that had been further subjected to distillation and dehydration treatment was added dropwise, and the mixture was allowed to react for an additional 30 minutes (forming a precursor of the second polymer block B).
Next, 27.0 g of 4-(1-ethoxyethoxy)styrene that had been further dehydrated by distillation was added dropwise, and after completion of the dropwise addition, the reaction was continued for an additional 30 minutes (formation of a precursor of the first polymer block C). Next, 16.0 g of styrene that had been further dehydrated by distillation was added dropwise, and the reaction was continued for 30 minutes (formation of a precursor of the second polymer block C). Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 130 g of a hexablock copolymer (BP-7).

Next, 50 g of the obtained hexablock copolymer (BP-7) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
The resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected hexablock copolymer. The deprotected hexablock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the hexablock copolymer (BP-8).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of a hexablock copolymer (BP-8).

Next, 38 g of the obtained hexablock copolymer (BP-8) was dissolved in 100 g of THF and the solution was poured into a glass reactor equipped with a heating and stirring device and a cooling device, and then 0.4 g of potassium t-butoxide was added. After nitrogen substitution, stirring was started and the temperature was raised to 130°C, followed by stirring at the same temperature for 8 hours (first-stage addition reaction).
Next, 29.6 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was successively added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction).The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 62 g of the target hexablock copolymer (BP-9).

The resulting hexablock copolymer (BP-9) was used to measure the composition ratio (molar ratio), Mn, Mw, and PDI of the hexablock copolymer (BP-9) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2.
First polymer block (A+B+C): Second polymer block (A+B+C)=48:52
Mn=10082
Mw = 10989
PDI = 1.09

Next, the identity period (d) and hp of the pattern created using the above-mentioned method were measured. The identity period (d) was found to be 8.4 nm, and hp was 4.2 nm. The measurement results are shown in Table 2 below.

(Example 4: Synthesis of diblock copolymer (BP-12))
After drying a 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 24.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 81.0 g of 4-(1-ethoxyethoxy)styrene that had been purified by distillation was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes (formation of a first polymer block precursor). Next, 48.0 g of styrene that had been subjected to distillation and dehydration treatment was added dropwise and the reaction was continued for an additional 30 minutes (formation of a second polymer block precursor).
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 132 g of a diblock copolymer (BP-10).

Next, 50 g of the obtained diblock copolymer (BP-10) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
Next, the resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. Next, the deprotected diblock copolymer solution was added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-11).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 39 g of a white powder solid of diblock copolymer (BP-11).

Next, 39 g of the resulting diblock copolymer (BP-11) was dissolved in 100 g of THF and poured into a glass reactor equipped with a heating and stirring device and a cooling device. 0.4 g of potassium t-butoxide was then added, and the mixture was purged with nitrogen and then stirred. The mixture was heated to 130°C and stirred at that temperature for 8 hours (first-stage addition reaction). Next, 29.1 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction). The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 62 g of the desired diblock copolymer (BP-12).

The resulting diblock copolymer (BP-12) was used to measure the composition ratio (molar ratio), Mn, Mw, and PDI of the diblock copolymer (BP-12) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below.
First polymer block:second polymer block=48:52
Mn=3387
Mw = 3590
PDI = 1.06

Next, the identity period (d) and hp of the pattern created using the above-mentioned method were measured. As a result, the identity period (d) was 10.0 nm and hp was 5.0 nm. The measurement results are shown in Table 2 below.

Example 5: Synthesis of diblock copolymer (BP-15)
After drying a 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 1.60 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 81.0 g of 4-(1-ethoxyethoxy)styrene that had been subjected to distillation and purification treatment was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition was completed, the reaction was continued for an additional 30 minutes (formation of a first polymer block precursor). Next, 48.0 g of styrene that had been subjected to distillation and dehydration treatment was added dropwise and the reaction was continued for an additional 30 minutes (formation of a second polymer block precursor).
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 129 g of a diblock copolymer (BP-13).

Next, 50 g of the obtained diblock copolymer (BP-13) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
Next, the resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. Next, the deprotected diblock copolymer solution was added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-14).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of diblock copolymer (BP-14).

Next, 38 g of the resulting diblock copolymer (BP-14) was dissolved in 100 g of THF and poured into a glass reactor equipped with a heating and stirring device and a cooling device. 0.4 g of potassium t-butoxide was then added, and the mixture was purged with nitrogen. Stirring was then initiated, the temperature was raised to 130°C, and the mixture was stirred at that temperature for 8 hours (first-stage addition reaction). Next, 29.8 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction). The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 62 g of the desired diblock copolymer (BP-15).

The resulting diblock copolymer (BP-15) was used to measure the composition ratio (molar ratio), Mn, Mw, and PDI of the diblock copolymer (BP-15) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below.
First polymer block:second polymer block=48:52
Mn=49408
Mw = 53361
PDI = 1.08

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

(Example 6: Synthesis of diblock copolymer (BP-18))
After drying a 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 8.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 81.0 g of 4-(1-ethoxyethoxy)styrene that had been purified by distillation was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition, the reaction was continued for an additional 30 minutes (formation of a first polymer block precursor). Next, 48.0 g of styrene that had been subjected to distillation and dehydration treatment was added dropwise and the reaction was continued for an additional 30 minutes (formation of a second polymer block precursor).
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 130 g of a diblock copolymer (BP-16).

Next, 50 g of the obtained diblock copolymer (BP-16) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
Next, the resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. Next, the deprotected diblock copolymer solution was added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-17).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of a diblock copolymer (BP-17).

Next, 38 g of the resulting diblock copolymer (BP-17) was dissolved in 100 g of THF and poured into a glass reactor equipped with a heating and stirring device and a cooling device. 0.4 g of potassium t-butoxide was then added, and the mixture was purged with nitrogen. Stirring was then initiated, the mixture was heated to 130°C, and stirred at that temperature for 8 hours (first-stage addition reaction). Next, 48.2 g of 1-chloro-1,1,3,3,5,5,5-heptamethyldisiloxane was added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction). The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 81 g of the desired diblock copolymer (BP-18).

The composition ratio (molar ratio), Mn, Mw, and PDI of the diblock copolymer (BP-18) obtained were measured by the above-mentioned measurement methods. The measurement results are shown below and in Table 2.
First polymer block:second polymer block=48:52
Mn = 12981
Mw=14019
PDI = 1.08

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

Example 7: Synthesis of diblock copolymer (BP-21)
After drying a 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 8.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 81.0 g of 4-(1-ethoxyethoxy)styrene that had been purified by distillation was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After the dropwise addition, the reaction was continued for an additional 30 minutes (formation of a first polymer block precursor). Next, 46.0 g of methyl methacrylate that had been subjected to distillation and dehydration treatment was added dropwise and allowed to react for 30 minutes (formation of a second polymer block precursor).
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 128 g of a diblock copolymer (BP-19).

Next, 50 g of the obtained diblock copolymer (BP-19) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
Next, the resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. Next, the deprotected diblock copolymer solution was added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-20).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of diblock copolymer (BP-20).

Next, 38 g of the resulting diblock copolymer (BP-20) was dissolved in 100 g of THF and poured into a glass reactor equipped with a heating and stirring device and a cooling device. 0.4 g of potassium t-butoxide was then added, and the mixture was purged with nitrogen. Stirring was then initiated, the temperature was raised to 130°C, and the mixture was stirred at that temperature for 8 hours (first-stage addition reaction). Next, 30.1 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction). The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 62 g of the desired diblock copolymer (BP-21).

The resulting diblock copolymer (BP-21) was used to measure the composition ratio (molar ratio), Mn, Mw, and PDI of the diblock copolymer (BP-21) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below.
First polymer block:second polymer block=48:52
Mn=9908
Mw=10701
PDI = 1.08

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

(Example 8: Synthesis of diblock copolymer (BP-24))
After drying a 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation and dehydration treatment using metallic sodium and anthracene was poured into the reactor and cooled to -70°C. Next, 8.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 81.0 g of 4-(1-ethoxyethoxy)styrene that had been purified by distillation was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C. After completion of the dropwise addition, the reaction was continued for an additional 30 minutes (formation of a first polymer block precursor). Next, a mixed solution of 24.0 g of styrene and 23.0 g of methyl methacrylate that had been subjected to further distillation and dehydration treatment was added dropwise and allowed to react for 30 minutes (formation of a second polymer block precursor).
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 129 g of a diblock copolymer (BP-22).

Next, 50 g of the obtained diblock copolymer (BP-22) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
Next, the resulting reaction solution was concentrated under reduced pressure, and then 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. Next, the deprotected diblock copolymer solution was added to 4.5 L of ultrapure water to precipitate the diblock copolymer (BP-23).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of diblock copolymer (BP-23).

Next, 38 g of the resulting diblock copolymer (BP-23) was dissolved in 100 g of THF and poured into a glass reactor equipped with a heating and stirring device and a cooling device. 0.3 g of potassium t-butoxide was then added, and the mixture was purged with nitrogen. Stirring was then initiated, the mixture was heated to 130°C, and stirred at that temperature for 8 hours (first-stage addition reaction). Next, 29.8 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction). The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 62 g of the desired diblock copolymer (BP-24).

The resulting diblock copolymer (BP-24) was used to measure the composition ratio (molar ratio), Mn, Mw, and PDI of the diblock copolymer (BP-24) by the above-mentioned measurement methods. The measurement results are shown below and in Table 2 below.
First polymer block:second polymer block=48:52
Mn=9970
Mw = 10768
PDI = 1.08

Next, the identity period (d) and hp of the pattern created using the above method were measured. The identity period (d) was found to be 19.0 nm, and hp was found to be 9.5 nm. The measurement results are shown in Table 2 below.

(Comparative Example 1: Synthesis of diblock copolymer (RBP-2))
A 5 L anionic polymerization reactor was dried under reduced pressure, and then 4,500 g of a tetrahydrofuran (THF) solution that had been subjected to distillation dehydration treatment using metallic sodium and anthracene was poured into the reactor under reduced pressure, followed by cooling to -70°C. Next, 5.00 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was poured into the cooled THF solution. Next, 48.9 g of styrene that had been subjected to distillation purification treatment was added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution did not exceed -60°C, and after completion of the dropwise addition, the reaction was continued for an additional 30 minutes.
Next, 90.0 g of 4-(1-ethoxyethoxy)styrene that had been further dehydrated by distillation was added dropwise and reacted for 30 minutes.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 100 g of a diblock copolymer (RBP-1).

Next, 50 g of the obtained diblock copolymer (RBP-1) was dissolved in 300 g of THF and poured into a 1 L reaction vessel, after which 175 g of methanol and 1 g of oxalic acid were added and a deprotection reaction was carried out for 20 hours at 40° C. under a nitrogen atmosphere. Next, the reaction solution was cooled to around room temperature, and then 2 g of pyridine was added to carry out a neutralization reaction.
The resulting reaction solution was then concentrated under reduced pressure, and 100 g of THF and 100 g of acetone were added to redissolve the deprotected diblock copolymer. The deprotected diblock copolymer solution was then added to 4.5 L of ultrapure water to precipitate the diblock copolymer (RBP-2).
Thereafter, the solid component was filtered and then dried under reduced pressure at 50° C. for 20 hours to obtain 38 g of a white powder solid of diblock copolymer (RBP-2).

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

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

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

The polystyrene (PSt) described below is a polymer having styrene (St) as a constituent unit.
Polymethyl methacrylate (PMMA) is a polymer whose constituent unit is methyl methacrylate (MMA).
The random copolymer of PSt and PMMA is a random copolymer of polystyrene (PSt) and polymethyl methacrylate (PMMA).
Poly 4-(4,4,4-tri-PSt-PMMA random copolymer methylsiloxy-2,2-dimethylsiloxy)styrene (PTMSDMSSt, in general formula (1), R ¹ represents a hydrogen atom, and X is a substituent in general formula (2) where b is 1) is a polymer having 4-(4,4,4-trimethylsiloxy-2,2-dimethylsiloxy)styrene (TMSDMSSt) as a constituent unit.
Poly4-(6,6,6-trimethylsiloxy-4,4-dimethylsiloxy-2,2-dimethylsiloxy)styrene (PTMSTMDSSt, in general formula (1), R ¹ represents a hydrogen atom, and X is a substituent in general formula (2) where b is 2)) is a polymer containing 4-(6,6,6-trimethylsiloxy-4,4,2,2-tetramethyldisiloxy)styrene (TMSTTMDSSt) as a constituent unit.
Poly(4-hydroxystyrene) (PHSt) is a polymer having 4-hydroxystyrene (HSt) as a structural unit.

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

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

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

The weight average molecular weight and molecular weight distribution of the obtained polymethyl methacrylate (PMMA) were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100000
・Molecular weight distribution (Mw/Mn) = 1.90

<PSt-PMMA random copolymer>
A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.), equipped with a Dimroth condenser, a thermometer, and a vacuum line, and the flask was subjected to three cycles of reduced pressure and nitrogen purging. Subsequently, 10.3 g of styrene (St), 10.3 g of methyl methacrylate (MMA), and 20.0 g of toluene were added, and the reaction solution in the flask was stirred with a magnetic stirrer while bubbling with nitrogen at 0°C for 15-20 minutes. The reaction solution was then stirred for 5 hours in an oil bath while being heated to 70°C. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask, and the resulting precipitate was collected by vacuum filtration. The collected precipitate was then dried in vacuo at 60°C to obtain 15 g of PSt-PMMA random copolymer.

The weight average molecular weight and molecular weight distribution of the obtained PSt-PMMA random copolymer were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100000
・Molecular weight distribution (Mw/Mn) = 1.90

<Poly 4-(4,4,4-trimethylsiloxy-2,2-dimethylsiloxy)styrene (PTMSDMSSt)>
A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.), and equipped with a Dimroth condenser, a thermometer, and a vacuum line. The flask was then subjected to three cycles of reduced pressure and nitrogen purging. Subsequently, 9.2 g of 4-hydroxystyrene (HSt) and 20.0 g of toluene were added, and the reaction solution in the flask was stirred with a magnetic stirrer while bubbling with nitrogen at 0°C for 15-20 minutes. The reaction solution was then stirred for 5 hours in an oil bath while being heated to 70°C. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask, and the resulting precipitate was collected by vacuum filtration. The collected precipitate was then dried under vacuum at 60°C to obtain 7 g of poly(4-hydroxystyrene) (PHSt).

Next, 7 g of the resulting poly 4-hydroxystyrene (PHSt) was dissolved in 100 g of THF and poured into a glass reactor equipped with a heating and stirring device and a cooling device. 0.1 g of potassium t-butoxide was then added, and the atmosphere was replaced with nitrogen. Stirring was then initiated, the temperature was raised to 130°C, and the mixture was stirred at that temperature for 8 hours (first-stage addition reaction). Next, 14.1 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction). The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 20 g of the desired poly 4-(4,4,4-trimethylsiloxy-2,2-dimethylsiloxy)styrene (PTMSDMSSt).

The weight average molecular weight and molecular weight distribution of the resulting poly 4-(4,4,4-trimethylsiloxy-2,2-dimethylsiloxy)styrene (PTMSDMSSt) were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100000
・Molecular weight distribution (Mw/Mn) = 1.90

<Poly 4-(6,6,6-trimethylsiloxy-4,4,2,2-tetramethyldisiloxy)styrene (PTMSTMDSSt)>
A 50 mL three-neck flask was charged with 0.063 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Nippon Finechem Co., Ltd.), and equipped with a Dimroth condenser, a thermometer, and a vacuum line. The flask was then subjected to three cycles of reduced pressure and nitrogen purging. Subsequently, 6.5 g of 4-hydroxystyrene (HSt) and 20.0 g of toluene were added, and the reaction solution in the flask was stirred with a magnetic stirrer while bubbling with nitrogen at 0°C for 15-20 minutes. The reaction solution was then stirred for 5 hours in an oil bath while being heated to 70°C. The three-neck flask was removed from the oil bath and cooled on ice. Next, 100 g of methanol was added to the three-neck flask, and the resulting precipitate was collected by vacuum filtration. The collected precipitate was then dried under vacuum at 60°C to obtain 5 g of poly(4-hydroxystyrene) (PHSt).

Next, 5 g of the resulting poly(4-hydroxystyrene) (PHSt) was dissolved in 100 g of THF and poured into a glass reactor equipped with a heating/stirring device and a cooling device. 0.1 g of potassium t-butoxide was then added, and the mixture was purged with nitrogen. Stirring was then initiated, the temperature was raised to 130°C, and the mixture was stirred at that temperature for 8 hours (first-stage addition reaction). Next, 37.2 g of 1-chloro-1,1,3,3,3-pentamethyldisiloxane was added dropwise at a pressure of 0.3 MPaG or less, and the mixture was stirred at the same temperature for 3 hours until the pressure reached equilibrium (second-stage addition reaction). The polymerization reaction was then terminated, and the reaction solution was concentrated to yield 20 g of the desired poly(4-(6,6,6-trimethylsiloxy-4,4,2,2-tetramethyldisiloxy)styrene (PTMSTMDSSt).

The weight average molecular weight and molecular weight distribution of the resulting poly 4-(6,6,6-trimethylsiloxy-4,4,2,2-tetramethyldisiloxy)styrene (PTMSTMDSSt) were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100000
・Molecular weight distribution (Mw/Mn) = 1.90

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

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

Each solution was prepared by dissolving 1 g of each polymer for evaluation in 99 g of propylene glycol monomethyl ether acetate. The resulting solution was applied to a silicon wafer using a spin coater (MIKASA Corporation, SPINCOATER 1H-360S). The coating was heated at 120°C for 60 seconds to form a polymer layer (film thickness approximately 600 nm) as a sample for etching rate measurement.
The etching device used was a batch-type plasma cleaner PX-250 manufactured by March Plasma Systems, Inc. The thickness of the polymer layer before and after etching was measured using an F20 manufactured by Filmetrics, Inc., and compared to determine the etching rate (nm/sec).
The ratio of the etching rate of each polymer layer to the etching rate of the polystyrene (PSt) film was determined as the etching rate ratio.
The smaller the etching rate ratio of the second polymer block to the first polymer block, the more difficult it is to remove by etching, and the larger the etching rate ratio of the second polymer block to the first polymer block, the more easily it is to remove by etching.

As shown in Table 1, PTMSDMSSt and PTMSTMDSSt, which correspond to the first polymer block, exhibited smaller etching rate ratios than PSt, PMMA, and the random copolymer of PSt and PMMA, which correspond to the second polymer block.
These results confirmed that domains mainly containing the second polymer block could be removed with high selectivity from the lamellar structures formed by phase separation of the block copolymers of Examples 1 to 8, which had PTMSDMSSt, a first polymer block corresponding to PTMSTMDSSt, and a second polymer block corresponding to PSt, PMMA, and a random copolymer of PSt and PMMA.
The first polymer block of the copolymers prepared in Examples 1 to 5 and 7 to 8 corresponds to PTMSDMSSt, and the first polymer block of the copolymer prepared in Example 6 corresponds to PTMSTMDSSt.
The second polymer block of the copolymers prepared in Examples 1 to 6 corresponds to PSt, the second polymer block of the copolymer prepared in Example 7 corresponds to PMMA, and the second polymer block of the copolymer prepared in Example 8 corresponds to a random copolymer of PSt and PMMA.
The first polymer block of the copolymer prepared in Comparative Example 1 corresponds to PSt, and the second polymer block corresponds to PHSt.

<Etching resistance evaluation results>
For each example, the ratio of the etching rate of the polymer for evaluation corresponding to the first polymer block to the etching rate of the random copolymer of PSt and PMMA, and PSt and PMMA, corresponding to the second polymer block of each block copolymer, was calculated as the rate ratio, and the results were evaluated according to the following criteria.
For example, in the case of Example 1, the ratio of the etching rate of PTMSDMSSt to the etching rate of PSt was calculated as the rate ratio, and the rate ratio was found to be 0.20.
In the comparative example, the etching rate of PHSt was faster than that of PSt, and the first polymer block was PSt and the second polymer block was PHSt, so the ratio of the etching rate of PSt to the etching rate of PHSt was calculated as the rate ratio.
The results are shown in Table 2.
Good: The etching rate ratio was 0.30 or less.
x: The etching rate ratio exceeded 0.30.

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

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

Claims (12)

A first polymer block including a constitutional unit represented by the following general formula (1),
a second polymer block including a structural unit represented by the following general formula (3) and/or a structural unit derived from an alkyl (meth)acrylate;
A polymer material containing a multiblock copolymer in which the following are linked:
[In general formula (1), ^R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, a represents an integer of 1 or more and 1,000 or less, and X represents a substituent represented by general formula (2)]
[In general formula (2), b is an integer of 1 or more and 5 or less.]
[In general formula (3), ^R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and c represents an integer of 1 to 1,000.] The polymer material described in claim 1, wherein the multiblock copolymer is a diblock copolymer or greater and a hexablock copolymer or less. The polymer material according to claim 1 or 2, wherein the multiblock copolymer is copolymerized by living anionic polymerization. The polymer material according to claim 1 or 2, wherein the multiblock copolymer has a number average molecular weight of 3,000 or more and 50,000 or less. A first polymer block including a constitutional unit represented by the following general formula (1),
and a second polymer block comprising a structural unit represented by the following general formula (3) and/or a structural unit derived from a (meth)acrylic acid alkyl ester.
[In general formula (1), ^R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, a represents an integer of 1 or more and 1,000 or less, and X represents a substituent represented by general formula (2)]
[In general formula (2), b is an integer of 1 or more and 5 or less.]
[In general formula (3), ^R2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and c represents an integer of 1 to 1,000.] A self-assembled monolayer obtained using the polymer material described in claim 1 or 2. The self-assembled monolayer according to claim 6, wherein a top coating agent is applied to the surface. A method for producing a self-assembled film, which forms a self-assembled film using the polymer material described in claim 1 or 2. The method for manufacturing a self-assembled film according to claim 8, in which a self-assembled film is formed within a guide pattern. The method for producing a self-assembled film according to claim 8, further comprising the step of applying a top coating agent onto the self-assembled film. A pattern formed by etching the self-assembled film described in claim 6. A pattern forming method comprising the step of etching the self-assembled film according to claim 6 to form a pattern.