JP2023116070A - Polymer material, self-assembled film, method for producing self-assembled film, pattern and method for producing pattern - Google Patents

Abstract

To provide a polymer material which can suppress the effect on the half pitch of a pattern to be formed and can form a uniform self-assembled film even if there is a difference in the molecular weight of constituent block copolymers, has excellent etching resistance and also has excellent strength of the self-assembled film.SOLUTION: There is provided a polymer material comprising a multi-block copolymer obtained by linking a first polymer block containing a structural unit represented by the general formula (1) and a second polymer block containing a predetermined structural unit, which is a diblock copolymer or more. (wherein, R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms and l is an integer of 1 or more and 1000 or less and X is a substituent represented by the predetermined formula.)SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a polymer material, a self-assembled film, a method for producing a self-assembled film, a pattern, and a method for forming a pattern.

With the miniaturization of electronic components including semiconductors, the demand for lithography technology capable of forming fine patterns is increasing.

Among them, a technique using directed self-assembly (DSA) utilizing microphase separation of a block copolymer is capable of forming a fine pattern at low cost. It is attracting attention as a next-generation lithography technology.

As such a technique, for example, in Patent Document 1, on a substrate having a surface roughness of at least 1 nm or more, block copolymerization in which at least two or more mutually incompatible polymers are bonded at their terminals is disclosed. A block copolymer film having a microdomain structure on which a coalescing resin is placed and oriented perpendicularly to the substrate surface, wherein the block copolymer resins are at least two types of block copolymer resins having different molecular weights. A polymer membrane is disclosed which is characterized as being a mixture of

JP-A-2005-8701

In general, in polymeric materials, strength increases as the degree of polymerization of the copolymer increases (as the weight average molecular weight (Mw) of the copolymer increases).
The present inventors have investigated conventional induced self-assembly materials, and found that polymerization of block copolymers constituting constituents in order to impart strength to induced self-assembled films (also simply referred to as self-assembled films) When the degree is increased (when the weight average molecular weight (Mw) is increased), the half pitch (hp) of the pattern to be formed increases, and a uniform self-assembled film cannot be formed (that is, when the hp is small and it is difficult to achieve both uniformity and strength of the self-assembled film).
In conventional induced self-assembly materials, the above problems have not been sufficiently investigated, and there is room for further improvement.

In addition, with conventional guided self-assembly materials, when a pattern is formed and then etched, the polymer film is reduced, making it impossible to form a pattern with a desired shape (etching resistance is poor). enough), and there is room for further improvement.

Therefore, the present invention has been made in view of the above problems. An object of the present invention is to provide a polymer material capable of forming a film, having excellent etching resistance, and having excellent strength of a self-assembled film.

The present inventors have made intensive studies on the above problems, and found that a first polymerization block containing a structural unit represented by the general formula (1) described later and a second polymer block containing a structural unit represented by the general formula (3) In order to improve the strength of the self-assembled film by containing a multi-block copolymer more than a diblock copolymer formed by connecting polymer blocks, the weight of the constituting block copolymer (polymer block) It has been found that even if the average molecular weight (Mw) is increased, an increase in the half pitch of the pattern to be formed can be suppressed, and a self-assembled film that is uniform and excellent in strength can be formed.
In addition, the present inventors have found that the obtained multi-block copolymer has the property of vertical studing by including a first polymer block containing a structural unit represented by the general formula (1) described later. The inventors have found that the etching resistance can be improved by utilizing the properties, and have arrived at the present invention.

That is, in the present invention, a first polymer block containing a structural unit represented by the following general formula (1) and a second polymer block containing a structural unit represented by the following general formula (3) are linked. A polymeric material containing a multi-block copolymer of at least a diblock copolymer; a self-assembled film obtained using the polymeric material; a self-assembled film that forms a self-assembled film using the polymeric material a pattern formed by etching the self-assembled film; and a pattern forming method comprising a step of etching the self-assembled film to form a pattern.

［一般式（１）中、Ｒ^１は、水素原子及び炭素数１～３のアルキル基を表す。ｌは、１以上１０００以下の整数であり、Ｘは、一般式（２）で表される置換基である。］

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

［一般式（２）中、ｍは、２以上８以下の整数である。］

[In general formula (2), m is an integer of 2 or more and 8 or less. ]

［一般式（３）中、Ｒ^２は、水素原子及び炭素数１～３のアルキル基を表す。ｎは、１以上１０００以下の整数である。］

[In general formula (3), R ² represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms. n is an integer of 1 or more and 1000 or less. ]

According to the present invention, even if there is a difference in the molecular weight of the constituting block copolymer, it is possible to suppress the influence on the half pitch of the pattern to be formed, form a uniform self-assembled film, and improve the etching resistance. It is also possible to provide a polymer material that is excellent in both the strength and the strength of the self-assembled membrane.

FIG. 1 is a diagram showing the relationship between the weight average molecular weight (Mw) and the half pitch (hp) of block copolymers produced in Examples and Comparative Examples.

(Polymer material)
In the polymer material of the present invention, a first polymer block containing a structural unit represented by the following general formula (1) and a second polymer block containing a structural unit represented by the following general formula (3) are linked. It contains a multi-block copolymer that is equal to or higher than the di-block copolymer.

［一般式（１）中、Ｒ^１は、水素原子及び炭素数１～３のアルキル基を表す。ｌは、１以上１０００以下の整数であり、Ｘは、一般式（２）で表される置換基である。］

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

［一般式（２）中、ｍは、２以上８以下の整数である。］

[In general formula (2), m is an integer of 2 or more and 8 or less. ]

［一般式（３）中、Ｒ^２は、水素原子及び炭素数１～３のアルキル基を表す。ｎは、１以上１０００以下の整数である。］

[In general formula (3), R ² represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms. n is an integer of 1 or more and 1000 or less. ]

Directed self-assembly (hereinafter also referred to as "DSA") technology is a technology that utilizes the ability to form microphase separation, which is expressed when two types of polymer chains that are incompatible with each other are linked at one point by copolymerization. be.
A multi-block copolymer linked by a covalent bond is formed according to the volume fraction ratio (f) between the two macromolecular components when the same macromolecular components aggregate between molecules to cause microphase separation. The interface curvature at the time of molecular assembly changes, and the microdomain structure changes.

A microdomain structure formed by two polymer components (for example, a first polymer block and a second polymer block) includes a spherical structure in which the first polymer block is finely dispersed in the second polymer block, and a second polymer block. A cylinder structure in which the first polymer blocks are linearly dispersed in the block, a gyroid structure in which a plurality of the first polymer blocks dispersed in the second polymer block are mutually bonded, and a second polymer block and the first polymer block. A lamellar structure is known in which is laminated in layers.
The polymer material of the present invention may exhibit any of the microdomain structures described above, but from the viewpoint of semiconductor pattern formation, it preferably exhibits a lamellar structure or a cylindrical structure.

R ¹ in the general formula (1) and R ² in the general formula (3) are not particularly limited as long as they are hydrogen atoms and alkyl groups having 1 to 3 carbon atoms.
Examples of the alkyl group having 1 to 3 carbon atoms include methyl group, ethyl group, n-propyl group and isopropyl group.
Among these, R ¹ and R ² are preferably a hydrogen atom or a methyl group from the viewpoint that defects based on defective microphase separation sites can be reduced and a fine and fine repeating pattern can be formed, and a hydrogen atom. is more preferred.

m in the general formula (2) is an integer of 2 or more and 8 or less.
From the viewpoint of reducing the half pitch (hp), m is preferably 2.

The first polymer block is preferably a block copolymer composed of structural units represented by the general formula (1).
When the first polymer block is composed of the structural unit represented by the general formula (1), the half pitch (hp) can be suitably reduced, and etching resistance can be suitably imparted.

The first polymer block may be a random copolymer composed of a structural unit represented by the above general formula (1) and a structural unit represented by the following general formula (4).
By making the first polymer block a random copolymer consisting of a structural unit represented by the above general formula (1) and a structural unit represented by the following general formula (4), the half pitch (hp) is preferably It is possible to reduce the amount of the compound that provides the structural unit represented by the above general formula (1), which is very expensive, while maintaining sufficient etching resistance.

［一般式（４）中、Ｒ^３は、水素原子及び炭素数１～３のアルキル基を表す。ｏは、１以上１０００以下の整数である。］

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

R ³ in the general formula (4) is not particularly limited as long as it is a hydrogen atom and an alkyl group having 1 to 3 carbon atoms.
Examples of the alkyl group having 1 to 3 carbon atoms include methyl group, ethyl group, n-propyl group and isopropyl group.
Among these, R ³ is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, from the viewpoints of reducing defects based on defective microphase separation sites and forming fine and fine repeating patterns.

In the structural units of the first polymer block, the molar ratio of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (4) (represented by the general formula (1) The structural unit: the structural unit represented by the above general formula (4) has a ratio of 10:0 to 6 from the viewpoint of suitably reducing the half pitch (hp) and suitably imparting etching resistance. : It is preferably within the range of 4, more preferably within the range of 10:0 to 8:2, and 10:0 (that is, the block combined with the structural unit represented by the general formula (1) polymer) is particularly preferred.

As the first polymer block of the multi-block copolymer, for example, the first polymer block A formed by repeatedly polymerizing the same structural unit represented by the above general formula (1), or the above general formula (1) and a structural unit different from the general formula (1) (e.g., a structural unit represented by the general formula (4)) are repeatedly randomly polymerized to form a first polymer block B. be able to.

As the second polymer block of the multi-block copolymer, for example, the second polymer block C formed by repeatedly polymerizing the same structural unit represented by the general formula (3), or the general formula (3) A second polymer block D obtained by repeatedly polymerizing a structural unit represented by and a structural unit different from the above general formula (3) can be used.

As the diblock copolymer, those in which the polymer blocks A to D described above are arbitrarily arranged such as AC, AD, BC and BD can be used.
A first polymerization in which the same structural unit represented by the above general formula (1) is repeatedly polymerized from the viewpoint of reducing defects based on defective microphase separation sites and forming fine and fine repeating patterns. A block A and a second polymer block C formed by repeatedly polymerizing the same structural unit represented by the general formula (3) are preferably arranged (AC).

Even if the weight average molecular weight (Mw) of the block copolymer of the pattern to be formed is increased, the above multi-block copolymer suitably suppresses the increase in half pitch, and is a self-assembled film that is more uniform and excellent in strength. From the viewpoint of forming the triblock copolymer or more is preferable.
Also in the triblock copolymer, the same structural unit represented by the general formula (1) is repeated from the viewpoint that defects based on the microphase separation defect site can be reduced and a fine and fine repeating pattern can be formed. and a second polymer block C (ACA, CAC) in which the same structural unit represented by the general formula (3) is repeatedly polymerized. .
In addition, it is preferable that the above-mentioned multi-block copolymer is equal to or less than an octa-block copolymer.
This is because it is difficult to synthesize a multi-block copolymer higher than a nonablock copolymer.

From the viewpoint of improving the uniformity and regularity of the pattern of the microdomain structure formed by self-organization, the ratio of the structural units of the multi-block copolymer is the molar ratio of the first polymer block and the second polymer block. The ratio (moles of the first polymer block:moles of the second polymer block) is preferably in the range of 8:2 to 2:8.

Further, when the lamellar structure or cylindrical structure described above is preferably formed, from the viewpoint of improving the uniformity and regularity of the pattern of the microdomain structure formed by self-organization, the first polymer block and the second polymer block (moles of the first polymer block:moles of the second polymer block) is more preferably in the range of 4:6 to 6:4, more preferably 5:5.

The multi-block copolymer 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. is preferred.
When the number average molecular weight (Mn) is 3,000 or more, self-organization progresses to obtain a self-assembled film in which a microdomain structure is formed. Further, when the number average molecular weight (Mn) is 50,000 or less, the hydrogen bonds of the hydrophilic groups of the polymer compound act appropriately, so that the pattern size can be easily made 8.0 nm or less.
The number average molecular weight (Mn) is more preferably 5,000 or more, even more preferably 6,000 or more. Further, the number average molecular weight (Mn) is more preferably 20,000 or less.
The polymeric material of the present invention also includes those having a number average molecular weight (Mn) of 10,000 or less as long as the effects of the present invention are exhibited.

The molecular weight distribution (PDI: Mw/Mn=PDI) of the multi-block copolymer is 1.0 or more from the viewpoint of being able to reduce defects based on defective microphase separation sites and form fine and fine repeated patterns. is preferred, 1.02 or more is more preferred, 1.1 or less is preferred, and 1.05 or less is more preferred.
If the PDI is 1.0 or more and 1.1 or less, there is almost no contamination with low molecular weight polymers and high molecular weight polymers, so the uniformity and regularity of the pattern of the microdomain structure formed by self-assembly are improved. do.

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

The composition ratio of the multi-block copolymer can be obtained by a nuclear magnetic resonance (NMR) method.
The composition ratio by the NMR method is determined, for example, by an NMR measurement device (trade name “JNM-ECZ400R”, manufactured by JEOL, analysis software: Delta 5.3.1, frequency: 400 MHz), temperature 25 ° C., solvent (CDCl ₃ ), internal Standard: tetramethylsilane (TMS), measurement can be performed under the conditions of 16 integration times.
The composition of the multi-block copolymer means the structural units constituting the multi-block copolymer, and the composition ratio means the molar ratio of the structural units constituting the multi-block copolymer.

The above multi-block copolymer is preferably copolymerized by living anionic polymerization.
A first polymerization block mainly composed of structural units represented by the general formula (1) copolymerized by a living anionic polymerization method, and a second polymerization mainly composed of structural units represented by the general formula (3) Multiblock copolymers with blocks are preferred.
The polymer material can be copolymerized by living anionic polymerization, so that the PDI can be extremely narrowed and a polymer compound having a desired number average molecular weight can be obtained with high accuracy. This makes it possible to improve the uniformity and regularity of the pattern of the microdomain structure formed by self-organization.

The method for producing the high molecular compound, which is the multi-block copolymer, is not particularly limited 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 little deactivation and side reactions of polymerization and enables living polymerization.

In the living anionic polymerization, deoxygenated and dehydrated monomers for polymerization and an organic solvent are used.
Examples of organic solvents include hexane, cyclohexane, toluene, benzene, diethyl ether, tetrahydrofuran, and the like. In the living anionic polymerization, a necessary amount of anionic species is added to these organic solvents, and then monomers are added as needed to carry out polymerization. Anionic species include, for example, organometallics such as alkyllithiums, alkylmagnesium halides, naphthalene sodium, and alkylated lanthanide compounds.

Since substituted styrene is copolymerized as a monomer in the polymer material of the present invention, s-butyllithium and butylmagnesium chloride are preferred as the anionic species.
The polymerization temperature of the living anionic polymerization is preferably in the range of −100° C. or higher and 50° C. or lower, and more preferably −70° C. or higher and 40° C. or lower from the viewpoint of facilitating control of the polymerization.

As a method for producing the above multi-block copolymer, for example, a substituted styrene monomer such as p-(1-ethoxyethoxy)styrene in which a phenolic hydroxyl group is protected is subjected to block copolymerization by living anionic polymerization under the conditions described above. to synthesize a block copolymer.
This block copolymer can deprotect the phenolic hydroxyl groups of a polymer compound obtained using an acid catalyst such as oxalic acid. Examples of protective groups for phenolic hydroxyl groups during polymerization include t-butyl groups and trialkylsilyl groups in addition to p-(1-ethoxyethoxy)styrene.
When copolymerizing monomers having other ether or ester sites in the polymer compound, selective deprotection is carried out by adjusting the acidity during the deprotection reaction and by performing the deprotection reaction under alkaline conditions. It is also possible to obtain phenolic hydroxyl groups by

The polymer material of the present invention can form a uniform self-assembled film by suppressing the influence on the half pitch of the pattern to be formed even if there is a difference in the molecular weight of the block copolymer that constitutes it. It is preferably used for self-organization (formation of self-assembled films) because it has excellent etching resistance and excellent strength of self-assembled films.

(Self-assembled membrane)
The self-assembled membrane of the invention is obtained using the polymer material of the invention.
Specifically, 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 for dissolving the polymer material is not particularly limited as long as a self-assembled film can be obtained. Examples include butyl acetate, amyl acetate, cyclohexyl acetate, 3-methoxybutyl acetate, methyl ethyl ketone, and methyl amyl ketone. , cyclohexanone, cyclopentanone, 3-ethoxyethylpropionate, 3-ethoxymethylpropionate, 3-methoxymethylpropionate, methyl acetoacetate, ethyl acetoacetate, diacetone alcohol, methyl pyruvate, ethyl pyruvate , propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether propionate, 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, dimethylsulfoxide, 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 and the like. These solvents may be used alone or in combination of two or more.

As the organic solvent for dissolving the polymer material, propylene glycol alkyl ether acetate and lactic acid alkyl ester are preferable. Examples of propylene glycol alkyl ether acetates include those having an alkyl group having 1 or more and 4 or less carbon atoms. Such alkyl groups include, for example, methyl, ethyl, propyl and butyl groups. Among these, a methyl group and an ethyl group are preferred. In addition, propylene glycol alkyl ether acetate has three isomers depending on the combination of substitution positions including 1,2-substituted and 1,3-substituted isomers, and these isomers may be used alone. You may use together 2 or more types of isomers.

Examples of the lactic acid alkyl ester include those having an alkyl group having 1 or more and 4 or less carbon atoms. Such alkyl groups include, for example, methyl, ethyl, propyl and butyl groups. Among these, a methyl group and an ethyl group are preferred.

As for the concentration of the organic solvent, for example, when propylene glycol alkyl ether acetate is used, it is preferable that the propylene glycol alkyl ether acetate is 50% by mass or more based on the total mass of the organic solvent. Moreover, when lactic acid alkyl ester is used, it is preferable to make it 50 mass % or more with respect to the total mass of the organic solvent.
Further, when a mixed solvent of propylene glycol alkyl ether acetate and lactic acid alkyl ester is used as the organic solvent, the total amount of the mixed solvent is preferably 50% by mass or more with respect to the total mass of the organic solvent. .
Moreover, when using this mixed solvent, it is preferable to make the propylene glycol alkyl ether acetate 60% by mass or more and 95% by mass or less and the lactic acid alkyl ester 5% by mass or more and 40% by mass or less. When the propylene glycol alkyl ether acetate is 60% by mass or more, the applicability of the polymer material is improved, and when it is 95% by mass or less, the solubility of the polymer material is improved.

The solution obtained by dissolving the polymeric material in an organic solvent is not particularly limited as long as it has a concentration at which a self-assembled film can be obtained by a conventionally known film forming method. , the organic solvent is preferably 5000 parts by mass or more and 50000 parts by mass or less, more preferably 7000 parts by mass or more and 30000 parts by mass or less.

The self-assembled film of the present invention can be produced by applying a solution obtained by dissolving a polymer material in an organic solvent.
The method of applying a solution of a polymer material dissolved in an organic solvent is not particularly limited as long as a self-assembled film can be obtained. Examples include spin coating, dipping, flexographic printing, inkjet printing, A spraying method, a potting method, a screen printing method, and the like can be mentioned.
The present invention also includes a method for producing a self-assembled film using the polymer material.

Since the self-assembled film of the present invention seals and protects the self-assembled film, the surface may be coated with a topcoat agent from the viewpoint of improving the handleability and weather resistance of the self-assembled film. preferable.

Examples of the topcoat agent include polyester-based topcoat agents, polyamide-based topcoat agents, polyurethane-based topcoat agents, epoxy-based topcoat agents, phenol-based topcoat agents, (meth)acrylic-based topcoat agents, and polyacetic acid. Examples include vinyl-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 topcoat agent can be applied onto the self-assembled film by a conventionally known application method.
A method for producing a self-assembled film, which includes the step of applying a topcoat agent onto the self-assembled film, is also included in the present invention.

An undercoat agent may be applied to the self-assembled film of the present invention.
Various conventionally known undercoating agents can be used as the undercoating agent.

The self-assembled film of the present invention preferably forms a self-assembled film within the guide pattern.
In this case, for example, a self-assembled film can be formed by applying a polymer material solution to a silicon substrate with a guide pattern.
Then, an annealing treatment is performed at 200° C. or higher and 300° C. or lower for 5 minutes or longer and 1 hour or shorter to obtain 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 8.0 nm or less can be obtained. .
The present invention also includes a pattern formed by etching the self-assembled film, and a pattern forming method including a step of etching the self-assembled film to form a pattern.

The cohesive force of the multi-block copolymer can be evaluated by transmission electron microscope (TEM) observation and X-ray small angle scattering (SAXS) measurement. For the cohesion evaluation sample, for example, 50 mg of a multi-block copolymer sample film is prepared, and the prepared sample is dissolved in 1 g of additive-free THF, transferred to a Teflon (registered trademark) petri dish, and treated with Teflon (registered trademark). It can be produced by casting in a petri dish for 10 days and vacuum drying.

In the TEM observation, first, after cutting the sample film into an appropriate size and placing it in an embedding mold, epoxy resin was poured into it and left to stand at 60°C for 12 hours to harden the epoxy resin and carry out the embedding process. do. Then, the sample membrane subjected to the embedding treatment using a microtome is cut into sections with a thickness of about 50 nm, the sections are collected on a Cu grid, stained with Cs ₂ CO ₃ , and then observed with a transmission electron microscope. hp can be measured by

In the SAXS measurement, for example, a block copolymer powder is heat-treated on a heat-resistant film, and an X-ray small-angle scattering (SAXS: small-angle X-ray scattering) analyzer (ultrafine periodic structure analysis system Nano-Viewer AXIS IV Rigaku) can be used to measure microphase separation in a bulk state.

In this microphase separation measurement, for example, X-rays are incident on a block copolymer sample film, and the angular dependence of scattering appearing on the small angle side is measured with an imaging plate for 60 minutes. Regarding measurement data processing, background correction such as air scattering is performed to calculate q/nm ^-1 , Fourier transform analysis is performed, and the average repeating pattern size width of the microdomain structure by self-assembly of the block copolymer It is possible to measure the value of the half pitch (hp) of the self-assembled film, which is half the identity period (d) of the .

Examples and comparative examples for clarifying the effects of the present invention will be described below. The present invention is in no way limited by the following examples and comparative examples.

(Example 1: Synthesis of tetrablock copolymer (BP-2))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 9.09 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 44.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene and 44.0 g of 4-pentamethyldisilylstyrene were successively added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of tetrablock copolymer (BP-1).

Next, 50 g of the obtained tetrablock copolymer (BP-1) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the tetrablock copolymer solution after deprotection was added to 4.5 L of ultrapure water to precipitate and wash the tetrablock copolymer (BP-2).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of tetrablock copolymer (BP-2).

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

As a result of GPC measurement with reference to standard polystyrene, the obtained tetrablock copolymer (BP-2) had an Mn of 9168, an Mw of 9535 and a PDI of 1.04.

<Measurement of composition ratio of tetrablock copolymer (BP-2)>
The composition ratio of the tetrablock copolymer (BP-2) obtained by nuclear magnetic resonance (NMR) spectroscopy ( ¹ H-NMR) was measured. Measurement conditions are shown below.
NMR measurement device: trade name “JNM-ECZ400R, manufactured by JEOL, analysis software: Delta 5.3.1”),
Frequency: 400MHz
temperature: 25°C,
Solvent: CDCl3,
Internal standard: tetramethylsilane (TMS)
Accumulated times: 16 times

It was confirmed that the signals derived from the 1-ethoxyethoxy group before deprotection (3 ppm to 4 ppm and around 5 ppm) disappeared after deprotection. Furthermore, from the area ratio of each signal, the composition ratio (molar ratio) of the tetrablock copolymer (BP-2) is 4-hydroxystyrene (HS):4-pentamethyldisilylstyrene (PMDSSt)=50:50. It turns out there is.

In the SAXS measurement, the block copolymer powder is heat-treated on a heat-resistant film, X-ray small-angle scattering (SAXS: small-angle X-ray scattering), an analyzer (ultrafine periodic structure analysis system: product name “Nano -Viewer AXIS IV" (manufactured by Rigaku) was used to measure microphase separation in a bulk state.
X-rays were incident on a block copolymer sample film, and the angular dependence of scattering appearing on the small angle side was measured for 60 minutes using an imaging plate. Regarding measurement data processing, background correction such as air scattering is performed to calculate q/nm ^-1 , Fourier transform analysis is performed, and the average repeating pattern size width of the microdomain structure by self-assembly of the block copolymer The value of the half pitch (hp) of the self-assembled film, which is half the identity period (d) of the self-assembled film, was measured.
As a result, the uniform period (d) was 7.6 nm and the half pitch (hp) was 3.8 nm. The measurement results are shown in Table 2 below.

(Example 2: Synthesis of tetrablock copolymer (BP-4))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 8.90 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, a mixture of 38.0 g of 4-pentamethyldisilylstyrene and 6.0 g of 4-trimethylsilylstyrene which had been subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise and reacted for 30 minutes. After that, a mixture of 38.0 g of 4-pentamethyldisilylstyrene and 6.0 g of 4-trimethylsilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of tetrablock copolymer (BP-3).

Next, 50 g of the obtained tetrablock copolymer (BP-3) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the tetrablock copolymer solution after deprotection was added to 4.5 L of ultrapure water to precipitate and wash the tetrablock copolymer (BP-4).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of tetrablock copolymer (BP-4).

Using the obtained tetrablock copolymer (BP-4), the composition ratio, Mn and PDI of the tetrablock copolymer (BP-4) were measured by the measurement methods described above. The measurement results are shown below and in Table 2 below.
・ Composition ratio (molar ratio) of tetrablock copolymer (BP-4)
4-hydroxystyrene (HS): {4-pentamethyldisilylstyrene (PMDSSt) and 4-trimethylsilylstyrene (TMSSt)} = 50:50
・Mn=9363
・Mw=9737
・PDI = 1.04

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

(Example 3: Synthesis of tetrablock copolymer (BP-6))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 9.09 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 50.0 g of 4-heptamethyltrisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise and reacted for 30 minutes. After that, 50.0 g of 4-pentamethyldisilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of tetrablock copolymer (BP-5).

Next, 50 g of the resulting tetrablock copolymer (BP-5) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected tetra-block copolymer solution was added to 4.5 L of ultrapure water to precipitate the tetra-block copolymer (BP-6) for washing.
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of tetrablock copolymer (BP-6).

Using the obtained tetrablock copolymer (BP-6), the composition ratio, Mn and PDI of the tetrablock copolymer (BP-6) were measured by the above-described measurement methods. The measurement results are shown below and in Table 2 below.
・ Composition ratio (molar ratio) of tetrablock copolymer (BP-6) 4-hydroxystyrene (HS): 4-heptamethyltrisilylstyrene (HMTSSt) = 50:50
・Mn=9819
・Mw=10211
・PDI = 1.04

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

(Example 4: Synthesis of diblock copolymer (BP-8))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 9.09 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 80.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 88.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of diblock copolymer (BP-7).

Next, 50 g of the obtained tetrablock copolymer (BP-7) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected diblock copolymer solution was added to 4.5 L of ultrapure water to precipitate and wash the diblock copolymer (BP-8).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of diblock copolymer (BP-8).

Using the obtained diblock copolymer (BP-8), the composition ratio, Mn and PDI of the diblock copolymer (BP-8) were measured by the measurement methods described above. The measurement results are shown below and in Table 2 below.
・ Composition ratio (molar ratio) of diblock copolymer (BP-8) 4-hydroxystyrene (HS): 4-pentamethyldisilylstyrene (PMDSSt) = 50:50
・Mn=9168
・Mw=9535
・PDI = 1.04

Next, the uniform period (d) and hp of the pattern produced by the method described above were measured. As a result, the identity period (d) was 13.0 nm and hp was 6.5 nm. The measurement results are shown in Table 2 below.

(Example 5: Synthesis of triblock copolymer (BP-10))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 9.09 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 88.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise to continue the polymerization reaction. After that, 30 g of methanol was added to stop the polymerization reaction, and the reaction solution was concentrated. to obtain 150 g of a triblock copolymer (BP-9).

Next, 50 g of the resulting triblock copolymer (BP-9) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected triblock copolymer solution was added to 4.5 L of ultrapure water to precipitate and wash the triblock copolymer (BP-10).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of triblock copolymer (BP-10).

Using the obtained triblock copolymer (BP-10), the composition ratio, Mn and PDI of the triblock copolymer (BP-10) were measured by the measurement methods described above. The measurement results are shown below and in Table 2 below.
・ Composition ratio (molar ratio) of triblock copolymer (BP-10) 4-hydroxystyrene (HS): 4-pentamethyldisilylstyrene (PMDSSt) = 50: 50
・Mn=9168
・Mw=9535
・PDI = 1.04

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

(Example 6: Synthesis of hexablock copolymer (BP-12))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 9.09 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 28.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 32.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 28.0 g of p-(1-ethoxyethoxy)styrene was dropped and reacted for 30 minutes. After that, 32.0 g of 4-pentamethyldisilylstyrene was dropped and reacted for 30 minutes. After that, 28.0 g of p-(1-ethoxyethoxy)styrene was dropped and reacted for 30 minutes. After that, 32.0 g of 4-pentamethyldisilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of hexablock copolymer (BP-11).

Next, 50 g of the resulting hexablock copolymer (BP-11) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected hexablock copolymer solution was added to 4.5 L of ultrapure water to precipitate and wash the hexablock copolymer (BP-12).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of hexablock copolymer (BP-12).

Using the obtained hexablock copolymer (BP-12), the composition ratio, Mn and PDI of the hexablock copolymer (BP-12) were measured by the measurement methods described above. The measurement results are shown below and in Table 2 below.
・ Composition ratio (molar ratio) of hexablock copolymer (BP-12) 4-hydroxystyrene (HS): 4-pentamethyldisilylstyrene (PMDSSt) = 50:50
・Mn=9819
・Mw=10211
・PDI = 1.04

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

(Example 7: Synthesis of tetrablock copolymer (BP-14))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 27.0 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 44.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise and reacted for 30 minutes. After that, 44.0 g of 4-pentamethyldisilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of tetrablock copolymer (BP-13).

Next, 50 g of the resulting tetrablock copolymer (BP-13) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected tetra-block copolymer solution was added to 4.5 L of ultrapure water to precipitate the tetra-block copolymer (BP-14) for washing.
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of tetrablock copolymer (BP-14).

Using the obtained tetrablock copolymer (BP-14), the composition ratio, Mn and PDI of the tetrablock copolymer (BP-14) were measured by the measurement methods described above. The measurement results are shown below and in Table 3 below.
・ Composition ratio (molar ratio) of tetrablock copolymer (BP-14) 4-hydroxystyrene (HS): 4-pentamethyldisilylstyrene (PMDSSt) = 50:50
・Mn=3129
・Mw=3254
・PDI = 1.04

Next, the uniform period (d) and hp of the pattern produced by the method described above were measured. As a result, the identity period (d) was 6.0 nm and hp was 3.0 nm. The measurement results are shown in Table 3 below.

(Example 8: Synthesis of tetrablock copolymer (BP-16))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 1.78 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 44.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise and reacted for 30 minutes. After that, 44.0 g of 4-pentamethyldisilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of tetrablock copolymer (BP-15).

Next, 50 g of the resulting tetrablock copolymer (BP-15) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected tetra-block copolymer solution was added to 4.5 L of ultrapure water to precipitate the tetra-block copolymer (BP-16) for washing.
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of tetrablock copolymer (BP-16).

Using the obtained tetrablock copolymer (BP-16), the composition ratio, Mn and PDI of the tetrablock copolymer (BP-16) were measured by the measurement methods described above. The measurement results are shown below and in Table 3 below.
・ Composition ratio (molar ratio) of tetrablock copolymer (BP-16) 4-hydroxystyrene (HS): 4-pentamethyldisilylstyrene (PMDSSt) = 50:50
・Mn=46558
・Mw=48420
・PDI = 1.04

Next, the uniform period (d) and hp of the pattern produced by the method described above were measured. As a result, the identity period (d) was 15.6 nm and hp was 7.8 nm. The measurement results are shown in Table 3 below.

(Example 9: Synthesis of triblock copolymer (BP-18))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 1.75 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 88.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise to continue the polymerization reaction. After that, 30 g of methanol was added to stop the polymerization reaction, and the reaction solution was concentrated. to obtain 150 g of a triblock copolymer (BP-17).

Next, 50 g of the resulting triblock copolymer (BP-17) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected triblock copolymer solution was added to 4.5 L of ultrapure water to precipitate and wash the triblock copolymer (BP-18).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of triblock copolymer (BP-18).

Using the obtained triblock copolymer (BP-18), the composition ratio, Mn and PDI of the triblock copolymer (BP-18) were measured by the measurement methods described above. The measurement results are shown below and in Table 3 below.
・ Composition ratio (molar ratio) of triblock copolymer (BP-18) 4-hydroxystyrene (HS): 4-pentamethyldisilylstyrene (PMDSSt) = 50: 50
・Mn=47355
・Mw = 49249
・PDI = 1.04

Next, the uniform period (d) and hp of the pattern produced by the method described above were measured. As a result, the identity period (d) was 15.8 nm and the hp was 7.9 nm. The measurement results are shown in Table 3 below.

(Example 10: Synthesis of hexablock copolymer (BP-20))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 1.90 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 28.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 32.0 g of 4-pentamethyldisilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 28.0 g of p-(1-ethoxyethoxy)styrene was dropped and reacted for 30 minutes. After that, 32.0 g of 4-pentamethyldisilylstyrene was dropped and reacted for 30 minutes. After that, 28.0 g of p-(1-ethoxyethoxy)styrene was dropped and reacted for 30 minutes. After that, 32.0 g of 4-pentamethyldisilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of hexablock copolymer (BP-19).

Next, 50 g of the resulting hexablock copolymer (BP-19) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected hexablock copolymer solution was added to 4.5 L of ultrapure water to precipitate and wash the hexablock copolymer (BP-20).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of a white powdery solid of hexablock copolymer (BP-20).

Using the obtained hexablock copolymer (BP-20), the composition ratio, Mn and PDI of the hexablock copolymer (BP-20) were measured by the measurement methods described above. The measurement results are shown below and in Table 3 below.
・ Composition ratio (molar ratio) of hexablock copolymer (BP-20) 4-hydroxystyrene (HS): 4-pentamethyldisilylstyrene (PMDSSt) = 50:50
・Mn=46732
・Mw = 48602
・PDI = 1.04

Next, the uniform period (d) and hp of the pattern produced by the method described above were measured. As a result, the identity period (d) was 15.4 nm and hp was 7.7 nm. The measurement results are shown in Table 3 below.

(Comparative Example 1: Synthesis of tetrablock copolymer (RBP-2))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 9.09 ml of s-butyllithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 40.0 g of 4-trimethylsilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise and reacted for 30 minutes. After that, 40.0 g of 4-trimethylsilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of tetrablock copolymer (RBP-1).

Next, 50 g of the obtained tetrablock copolymer (RBP-1) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the tetrablock copolymer solution after deprotection was added to 4.5 L of ultrapure water to precipitate and wash the tetrablock copolymer (RBP-2).
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of tetrablock copolymer (RBP-2).

Using the obtained tetrablock copolymer (RBP-2), the composition ratio, Mn and PDI of the tetrablock copolymer (RBP-2) were measured by the above-described measurement methods. The measurement results are shown below and in Table 3 below.
・ Composition ratio (molar ratio) of tetrablock copolymer (RBP-2) 4-hydroxystyrene (HS): 4-trimethylsilylstyrene (TMSSt) = 50:50
・Mn=8735
・Mw=9084
・PDI = 1.04

Next, the uniform period (d) and hp of the pattern produced by the method described above were measured. As a result, the identity period (d) was 8.4 nm and hp was 4.2 nm. The measurement results are shown in Table 3 below.

(Comparative Example 2: Synthesis of tetrablock copolymer (RBP-4))
After drying the 5 L anionic polymerization reactor under reduced pressure, 4500 g of a tetrahydrofuran (THF) solution that had been dehydrated by distillation with metallic sodium and anthracene was injected under reduced pressure and cooled to -70°C. Next, 1.70 ml of s-butyl lithium (cyclohexane solution: 2.03 mol/L) was injected into the cooled THF solution. Next, 40.0 g of p-(1-ethoxyethoxy)styrene purified by distillation is added dropwise while adjusting the dropping rate so that the internal temperature of the reaction solution does not exceed -60°C. React for 30 minutes.
Next, 40.0 g of 4-trimethylsilylstyrene which had been further subjected to distillation and dehydration treatment was added dropwise and reacted for 30 minutes. After that, 40.0 g of p-(1-ethoxyethoxy)styrene was added dropwise and reacted for 30 minutes. After that, 40.0 g of 4-trimethylsilylstyrene was added dropwise to continue the polymerization reaction.
Thereafter, 30 g of methanol was added to terminate the polymerization reaction, and the reaction solution was concentrated to obtain 150 g of tetrablock copolymer (RBP-3).

Next, 50 g of the resulting tetrablock copolymer (RBP-3) was dissolved in 300 g of THF and poured into a 1 L reaction vessel. A deprotection reaction was carried out for 20 hours. Next, after cooling the reaction solution to around room temperature, 2 g of pyridine was added to carry out a neutralization reaction.
Next, after concentrating the obtained reaction solution under reduced pressure, 100 g of THF and 100 g of acetone were injected to redissolve the deprotected tetrablock copolymer. Next, the deprotected tetra-block copolymer solution was added to 4.5 L of ultrapure water to precipitate the tetra-block copolymer (RBP-4) for washing.
Thereafter, the solid component was filtered with a filter and dried under reduced pressure at 50° C. for 20 hours to obtain 45 g of white powdery solid of tetrablock copolymer (RBP-4).

Using the obtained tetrablock copolymer (RBP-4), the composition ratio, Mn and PDI of the tetrablock copolymer (RBP-4) were measured by the measurement methods described above. The measurement results are shown below and in Table 3 below.
・ Composition ratio (molar ratio) of tetrablock copolymer (RBP-4) 4-hydroxystyrene (HS): 4-trimethylsilylstyrene (TMSSt) = 50:50
・Mn=46427
・Mw=48285
・PDI = 1.04

Next, the uniform period (d) and hp of the pattern produced by the method described above were measured. As a result, the identity period (d) was 40.0 nm and hp was 20.0 nm. The measurement results are shown in Table 3 below.

(Measurement of etching rate)
Polymers for evaluation were prepared from constituent units of the block copolymers prepared in Examples and Comparative Examples, and their etching rates (nm/sec) were measured. The measurement results are shown in Table 3 below.

Poly 4-hydroxystyrene (PHS) described below is a polymer for evaluation having 4-hydroxystyrene (HS) as a structural unit, and poly 4-pentamethyldisilylstyrene (PPMDSSt) is 4-penta A polymer for evaluation having methyldisilylstyrene (PMDSSt) as a structural unit, and poly 4-heptamethyltrisilylstyrene (PHMTSSt) is a polymer for evaluation having 4-heptamethyltrisilylstyrene (HMTSSt) as a structural unit. be.
In addition, a random copolymer of (4-trimethylsilylstyrene)-(4-pentamethyldisilylstyrene) (TMSSt-PMDSSt random copolymer) is an evaluation grade consisting of 4-hydroxystyrene (HS) and 4-trimethylsilylstyrene (TMSSt). Poly 4-trimethylsilylstyrene (PTMSSt) is an evaluation polymer having 4-trimethylsilylstyrene (TMSSt) as a structural unit.

<Poly 4-hydroxystyrene (PHS)>
Put 0.032 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Japan Finechem Co., Ltd.) in a 50 mL three-necked flask, attach a Dimroth condenser, a thermometer, and a vacuum line, and reduce the pressure. and nitrogen purge were repeated three times. followed by 20.5 g of 4-hydroxystyrene (HS) and 9.0 g of toluene. 0 g was added, and the reaction solution in the flask was stirred with a magnetic stirrer at 0° C. for 15 to 20 minutes with nitrogen bubbling. Thereafter, the reaction solution was stirred for 5 hours while being heated to 70° C. in an oil bath. The three-necked flask was removed from the oil bath and ice-cooled. Then, 40 g of tetrahydrofuran was added to the three-necked flask, and the resulting precipitate was purified in methanol to remove residual monomers and the like. The precipitate was collected by filtration under reduced pressure and dried in vacuum at 60° C. to obtain 15 g of poly-4-hydroxystyrene (PHS).

The weight average molecular weight and molecular weight distribution of the resulting poly-4-hydroxystyrene (PHS) were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100,000
・Molecular weight distribution (Mw/Mn) = 1.90

<Poly 4-pentamethyldisilylstyrene (PPMDSSt)>
Put 0.032 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Japan Finechem Co., Ltd.) in a 50 mL three-necked flask, attach a Dimroth condenser, a thermometer, and a vacuum line, and reduce the pressure. and nitrogen purge were repeated three times. Subsequently, 20.5 g of 4-pentamethyldisilylstyrene (PMDSSt) and 9.5 g of toluene. 0 g was added, and the reaction solution in the flask was stirred with a magnetic stirrer at 0° C. for 15 to 20 minutes with nitrogen bubbling. Thereafter, the reaction solution was stirred for 5 hours while being heated to 70° C. in an oil bath. The three-necked flask was removed from the oil bath and ice-cooled. Then, 40 g of tetrahydrofuran was added to the three-necked flask, and the resulting precipitate was purified in methanol to remove residual monomers and the like. The precipitate was collected by filtration under reduced pressure, and the collected precipitate was vacuum-dried at 60° C. to obtain 15 g of poly-4-pentamethyldisilylstyrene (PPMDSSt).

The weight average molecular weight and molecular weight distribution of the resulting poly-4-pentamethyldisilylstyrene (PPMDSSt) were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100,000
・Molecular weight distribution (Mw/Mn) = 1.90

<Poly 4-heptamethyltrisilylstyrene (PHMTSSt)>
Put 0.032 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Japan Finechem Co., Ltd.) in a 50 mL three-necked flask, attach a Dimroth condenser, a thermometer, and a vacuum line, and reduce the pressure. and nitrogen purge were repeated three times. Subsequently, 20.5 g of 4-heptamethyltrisilylstyrene (HMTSSt) and 9.5 g of toluene. 0 g was added, and the reaction solution in the flask was stirred with a magnetic stirrer at 0° C. for 15 to 20 minutes with nitrogen bubbling. Thereafter, the reaction solution was stirred for 5 hours while being heated to 70° C. in an oil bath. The three-necked flask was removed from the oil bath and ice-cooled. Then, 40 g of tetrahydrofuran was added to the three-necked flask, and the resulting precipitate was purified in methanol to remove residual monomers and the like. The precipitate was collected by filtration under reduced pressure, and dried in vacuum at 60° C. to obtain 15 g of poly-4-heptamethyltrisilylstyrene (PHMTSSt).

The weight average molecular weight and molecular weight distribution of the resulting poly-4-heptamethyltrisilylstyrene (PHMTSSt) were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100,000
・Molecular weight distribution (Mw/Mn) = 1.90

<(4-trimethylsilylstyrene)-(4-pentamethyldisilylstyrene) random copolymer (TMSSt-PMDSSt random copolymer)>
Put 0.032 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Japan Finechem Co., Ltd.) in a 50 mL three-necked flask, attach a Dimroth condenser, a thermometer, and a vacuum line, and reduce the pressure. and nitrogen purge were repeated three times. This was followed by 2.8 g of 4-trimethylsilylstyrene (TMSSt), 17.7 g of 4-pentamethylsilylstyrene (PMDSSt) and 9.9 g of toluene. 0 g was added, and the reaction solution in the flask was stirred with a magnetic stirrer at 0° C. for 15 to 20 minutes with nitrogen bubbling. Thereafter, the reaction solution was stirred for 5 hours while being heated to 70° C. in an oil bath. The three-necked flask was removed from the oil bath and ice-cooled. Then, 40 g of tetrahydrofuran was added to the three-necked flask, and the resulting precipitate was purified in methanol to remove residual monomers and the like. The precipitate was collected by filtration under reduced pressure, and the collected precipitate was vacuum-dried at 60° C. to obtain 15 g of TMSSt-PMDSSt random copolymer.

The weight average molecular weight, molecular weight distribution and monomer composition ratio (molar ratio) of the resulting TMSSt-PMDSSt random copolymer were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100,000
・Molecular weight distribution (Mw/Mn) = 1.90
・TMSSt: PMDSSt=17:83

<Poly 4-trimethylsilylstyrene (PTMSSt)>
Put 0.032 g of 2,2'-azobis(2-isobutyronitrile) (AIBN) (manufactured by Japan Finechem Co., Ltd.) in a 50 mL three-necked flask, attach a Dimroth condenser, a thermometer, and a vacuum line, and reduce the pressure. and nitrogen purge were repeated three times. Subsequently, 20.5 g of 4-trimethylsilylstyrene (TMSSt) and 9.5 g of toluene. 0 g was added, and the reaction solution in the flask was stirred with a magnetic stirrer at 0° C. for 15 to 20 minutes with nitrogen bubbling. Thereafter, the reaction solution was stirred for 5 hours while being heated to 70° C. in an oil bath. The three-necked flask was removed from the oil bath and ice-cooled. Then, 40 g of tetrahydrofuran was added to the three-necked flask, and the resulting precipitate was purified in methanol to remove residual monomers and the like. The precipitate was collected by filtration under reduced pressure, and the collected precipitate was vacuum-dried at 60° C. to obtain 15 g of poly-4-trimethylsilylstyrene (PTMSSt).

The weight average molecular weight and molecular weight distribution of the resulting poly-4-trimethylsilylstyrene (PTMSSt) were measured in the same manner as in Example 1. The measurement results are as follows.
・Mw: 100,000
・Molecular weight distribution (Mw/Mn) = 1.90

1 g of each evaluation polymer was dissolved in 99 g of propylene glycol monomethyl ether acetate to prepare each solution. The resulting solution was applied onto a silicone wafer using a spin coater (SPINCOATER 1H-360S, manufactured by MIKASA). The coating film was heated at 120° C. for 60 seconds to form a polymer layer (film thickness of about 600 nm) as a sample for etching rate measurement.
The polymer layer was dry plasma etched with a 100 W, 50 sccm oxygen plasma. A batch-type plasma cleaner PX-250 manufactured by March Plasma Systems was used as an etching apparatus. The thickness of the polymer layer before and after etching was compared by measuring using F20 manufactured by Filmetrics, Inc., and the etching rate (nm/sec) was obtained.
The ratio of the etching rate of the poly-4-hydroxystyrene (PHS) film to the etching rate of each polymer layer was obtained as the etching rate ratio. It can be said that the higher the etching rate ratio, the higher the selectivity of poly-4-hydroxystyrene (PHS) corresponding to the second polymerization block of the block copolymer.

As shown in Table 1, PPMDSSt, PHMTSSt, TMSSt-PMDSSt random copolymers showed a large etch rate ratio to PHS compared to PTMSSt.
From this result, the block copolymers of Examples 1 to 10 having a first polymer block corresponding to PPMDSSt, PHMTSSt or TMSSt-PMDSSt random copolymer and a second polymer block corresponding to PHS are formed by phase separation. It was confirmed that the domain mainly containing the second polymer block can be removed from the obtained lamellar structure with high selectivity.

<Evaluation results of etching resistance>
For the examples and comparative examples, the ratio of the etching rate of the PHS (corresponding to the second polymer block of each block copolymer) to the etching rate of the polymer for evaluation corresponding to the first polymer block was calculated as a rate ratio. was evaluated according to the criteria of
For example, in the case of Example 1, the ratio of the etching rate of PHS to the etching rate of PPMDSSt was calculated as a rate ratio, and the rate ratio was 8.0.
The results are shown in Tables 2 and 3.
O: The etching rate ratio was 5.0 or more.
x: The etching rate ratio was less than 5.0.

<Evaluation result of half pitch (hp)>
The half pitch (hp) of the self-assembled films measured in Examples and Comparative Examples was evaluated according to the following criteria. The results are shown in Tables 2 and 3.
O: The half pitch (hp) of the self-assembled film was 8.0 nm or less.
x: The half pitch (hp) of the self-assembled film exceeded 8.0 nm.

From Tables 2 and 3, it is confirmed that in Examples 1 to 10, the half pitch (hp) is sufficiently small and the PDI is small, so that a uniform self-assembled film can be formed. confirmed to be excellent.
FIG. 1 is a diagram showing the relationship between the weight average molecular weight (Mw) and the half pitch (hp) of the block copolymers produced in Examples and Comparative Examples.
As shown in FIG. 1, the first polymer block containing the structural unit represented by the general formula (1) and the second polymer block containing the structural unit represented by the general formula (3) are connected. For tetrablock copolymers (Examples 1, 7 and 8), triblock copolymers (Examples 5, 9), and hexablock copolymers (Examples 6 and 10), the weight average molecular weight (Mw) Since the half-pitch can be 8.0 nm or less even when the is about 50,000, it was confirmed that the increase in the half-pitch of the pattern to be formed can be suppressed even if the weight average molecular weight (Mw) is increased. That is, it was confirmed that in the block copolymers produced in Examples, the half pitch of the formed pattern was 8.0 nm or less, and a self-assembled film that was uniform and excellent in strength could be formed.

Claims (14)

a first polymer block containing a structural unit represented by the following general formula (1);
a second polymer block containing a structural unit represented by the following general formula (3);
A polymer material containing a multi-block copolymer that is not less than a di-block copolymer in which is linked.

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

[In general formula (2), m is an integer of 2 or more and 8 or less. ]

[In general formula (3), R ² represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms. n is an integer of 1 or more and 1000 or less. ] 2. The polymeric material according to claim 1, wherein the first polymer block is a block copolymer composed of structural units represented by the general formula (1). The polymer according to claim 1, wherein the first polymer block is a random copolymer comprising a structural unit represented by the general formula (1) and a structural unit represented by the following general formula (4). material.

[In general formula (4), R ³ represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms. o is an integer of 1 or more and 1000 or less. ] The polymer material according to any one of claims 1 to 3, wherein m is 2 in the general formula (2). The polymeric material according to any one of claims 1 to 4, wherein the multi-block copolymer is a tri-block copolymer or higher. The polymeric material according to any one of claims 1 to 5, wherein the multi-block copolymer is copolymerized by living anionic polymerization. The polymeric material according to any one of claims 1 to 6, wherein the multi-block copolymer has a number average molecular weight of 3,000 or more and 50,000 or less. A self-assembled film obtained using the polymer material according to any one of claims 1 to 7. 9. The self-assembled membrane according to claim 8, wherein the surface is coated with a topcoat agent. A method for producing a self-assembled film, comprising forming a self-assembled film using the polymer material according to any one of claims 1 to 7. The method for producing a self-assembled film according to claim 10, wherein the self-assembled film is formed within the guide pattern. 12. The method for producing a self-assembled film according to claim 10, further comprising the step of applying a topcoat agent onto the self-assembled film. A pattern obtained by etching the self-assembled film according to claim 8 or 9. 10. A pattern forming method, comprising the step of etching the self-assembled film according to claim 8 or 9 to form a pattern.

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