Patent Application
20240361686
The present invention relates to a method for manufacturing an etching mask pattern and a resin composition for forming an etching mask pattern.
Priority is claimed on Japanese Patent Application No. 2023-073812, filed on Apr. 27, 2023, Japanese Patent Application No. 2023-216947, filed on Dec. 22, 2023, and Japanese Patent Application No. 2024-067050, filed on Apr. 17, 2024, and the content of which is incorporated herein by reference.
In recent years, along with further miniaturization of large-scale integrated circuits (LSI), a technology for processing finer structure bodies has been demanded.
In response to such a demand, there has been developed a technology for forming a finer pattern by utilizing a phase-separated structure formed by self-organization of a block copolymer in which blocks incompatible with each other are bonded together (for example, see Japanese Unexamined Patent Application, First Publication No. 2008-36491).
In order to utilize the phase-separated structure of the block copolymer, it is considered essential to form self-organized nanostructures, which are formed by micro-phase separation, only in a specific region and arrange the nanostructures in a desired direction. In order to realize the position control and orientation control of these nanostructures, processes such as graphoepitaxy for controlling the phase-separated pattern by a guide pattern, and chemical epitaxy for controlling the phase-separated pattern by the difference in the chemical state of the substrate, have been proposed (for example, see Proceedings of SPIE, Vol. 7637, No. 76370G-1 (2010)).
The block copolymer forms a structure body having a regular periodic structure by the phase separation.
The phrase “period of a structure body” means the period of the phase structure observed when the structure body of a phase-separated structure is formed and refers to the sum of the lengths of the phases each of which is incompatible. In a case where the phase-separated structure forms a cylinder structure perpendicular to a surface of the substrate, the period (L0) of the structure body is a distance (pitch) between centers of two adjacent cylinder structures.
[in the expression, L0 represents a period of the structure body, a is a parameter indicating the size of the monomer, N represents a degree of polymerization, and x is an interaction parameter, in which the value thereof is higher, the phase separation performance is higher]
Accordingly, the period (L0) of the structure body can be controlled by adjusting the composition and the total molecular weight of the block copolymer.
It has been known that the periodic structure formed by the block copolymer varies the form such as a cylinder (columnar phase), a lamella (plate phase), and a sphere (spherical phase) depending on a ratio of a volume of the polymer components, and the period depends on the molecular weight.
In order to form a fine pattern by utilizing the phase-separated structure formed by the self-organization of the block copolymer, the phase-separated structure formed by the block copolymer preferably has vertical orientation. For example, in Examples of Japanese Unexamined Patent Application, First Publication No. 2022-20519, a block copolymer capable of forming a phase-separated structure having vertical orientation in a case where a film thickness of a block copolymer formed on a substrate is 24 nm is disclosed.
In order to apply the phase-separated structure formed of the block copolymer to an etching mask, it is necessary to perform vertical orientation with a relatively thick film thickness (for example, a film thickness of 25 nm or more). However, in the block copolymer disclosed in Japanese Unexamined Patent Application, First Publication No. 2022-20519, when the film thickness increases, it is difficult to form a phase-separated structure vertically oriented.
The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a resin composition for forming an etching mask pattern, with which a phase-separated structure vertically oriented can be formed even with a film thickness of 25 nm or more, and a method for manufacturing an etching mask pattern using the same.
The present invention includes the following aspects.
A first aspect of the present invention is a method for manufacturing an etching mask pattern, including a step of applying a resin composition for forming an etching mask pattern onto a support to form a layer containing a block copolymer and having a film thickness of 25 nm or more, and a step of phase-separating the layer containing the block copolymer, in which the resin composition for forming an etching mask pattern contains a block copolymer having a first block and a second block, the first block is composed of a polymer consisting of a repeating structure of a constitutional unit represented by General Formula (b1), the second block is composed of a random copolymer consisting of a structure in which a constitutional unit represented by General Formula (b2m) and a constitutional unit represented by General Formula (b2g) are arranged in a disordered manner, and a proportion of a volume of the first block to a total volume of the first block and the second block is 20% to 80% by volume.
A second aspect of the present invention is a resin composition for forming an etching mask pattern, the resin composition containing a block copolymer having a first block and a second block, in which the first block is composed of a polymer consisting of a repeating structure of a constitutional unit represented by General Formula (b1), the second block is composed of a random copolymer consisting of a structure in which a constitutional unit represented by General Formula (b2m) and a constitutional unit represented by General Formula (b2g) are arranged in a disordered manner, and a proportion of a volume of the first block to a total volume of the first block and the second block is 20% to 80% by volume.
According to the present invention, it is possible to provide a resin composition which can be used for an etching mask pattern, and a method for manufacturing an etching mask pattern using the same.
In the present specification and the scope of the present claims, the term “aliphatic” is a relative concept used with respect to “aromatic” and defines a group or compound that has no aromaticity.
A term “alkyl group” includes linear, branched, or cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to an alkyl group in an alkoxy group.
A term “alkylene group” includes linear, branched, or cyclic divalent saturated hydrocarbon groups unless otherwise specified.
A “halogenated alkyl group” is a group in which a part of or all of hydrogen atoms in an alkyl group are substituted with halogen atoms. As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are exemplary examples.
The “fluorinated alkyl group” or a “fluorinated alkylene group” is a group obtained by substituting part or all of hydrogen atoms of an alkyl group or an alkylene group with a fluorine atom.
A term “constitutional unit” indicates a monomer unit constituting a polymer compound (a resin, a polymer, or a copolymer).
An expression “may have a substituent” includes a case where a hydrogen atom (—H) is substituted with a monovalent group and a case where a methylene group (—CH2—) is substituted with a divalent group.
A term “exposure” is used as a general concept for irradiation with radiation.
A term “α-position (carbon atom at α-position)” means a carbon atom to which a side chain of a block copolymer is bonded, unless otherwise specified. The “carbon atom at the α-position” of a methyl methacrylate unit means a carbon atom to which a carbonyl group of methacrylic acid is bonded. The “carbon atom at the α-position” of a styrene unit means a carbon atom to which a benzene ring is bonded.
A term “number-average molecular weight” (Mn) is a number-average molecular weight in terms of standard polystyrene measured by size-exclusion chromatography, unless otherwise specified. A term “mass-average molecular weight” (Mw) is a mass-average molecular weight in terms of standard polystyrene measured by size-exclusion chromatography, unless otherwise specified. A value obtained by adding a unit (g·mol−) to the value of Mn or Mw represents a molar mass.
In the detailed description and claims of the present invention, in the specification and claims of the present invention, some structures represented by a chemical formula have an asymmetric carbon, and there may be enantiomers and diastereomers. Those isomers are collectively represented by one formula. These isomers may be used alone or in the form of a mixture.
The method for manufacturing an etching mask pattern according to the present embodiment includes a step of applying a resin composition for forming an etching mask pattern according to the embodiment onto a support to form a layer containing a block copolymer (hereinafter, referred to as “step (i)”), and a step of phase-separating the layer containing a block copolymer (hereinafter, referred to as “step (ii)”).
Hereinafter, the method for manufacturing an etching mask pattern will be specifically described with reference to
In the embodiment shown in
Next, the above-described resin composition for forming an etching mask pattern according to the embodiment is applied onto the undercoat agent layer 2 to form a layer (BCP layer) 3 containing the above-described component (BCP) (
Next, the BCP layer 3 is phase-separated into a phase 3a and a phase 3b by a heating and annealing treatment (
According to the production method of the embodiment, that is, the production method including the steps (i) and (ii), a structure body 3′ including a phase-separated structure is obtained on the support 1 on which the undercoat agent layer 2 has been formed. It is possible to manufacture an etching mask pattern using the structure body 3′ including the phase-separated structure.
The “first block” and “second block” in the resin composition for forming an etching mask pattern, which will be described later, may be referred to as “block (b1)” and “block (b2)”.
In the step (i), the support 1 is coated with the resin composition for forming an etching mask pattern to form the BCP layer 3 having a film thickness of 25 nm or more. The film thickness of the BCP layer 3 may be 28 nm or more, 30 nm or more, 32 nm or more, 34 nm or more, or 36 nm or more.
In the embodiment shown in
By providing the undercoat agent layer 2 on the support 1, a hydrophilic and hydrophobic balance between a surface of the support 1 and the layer 3 containing the block copolymer (BCP layer) can be achieved.
That is, in a case where the undercoat agent layer 2 contains a resin component having the constitutional unit constituting the above-described block (b1), adhesiveness between the phase of the BCP layer 3, formed of the block (b1), and the support 1 is enhanced. In a case where the undercoat agent layer 2 contains a resin component having the constitutional unit constituting the above-described block (b2), adhesiveness between the phase of the BCP layer 3, formed of the block (b2), and the support 1 is enhanced.
Accordingly, a cylinder structure or a lamellar structure, oriented in a direction perpendicular to the surface of the support 1, is likely to be formed due to the phase separation of the BCP layer 3.
As the undercoat agent, a resin composition containing a resin component can be used.
The resin component for the undercoat agent can be appropriately selected from the resin components known in the related art, which are used for forming a thin film depending on the type of the blocks constituting the component (BCP).
The resin component for the undercoat agent may be, for example, a thermopolymerizable resin or a photosensitive resin contained in a positive-tone resist composition, a negative-tone resist composition, or the like. In addition, a non-polymerizable film formed by applying a compound as a surface treating agent may be used as the undercoat agent layer. For example, a siloxane-based organic monomolecular film formed by applying phenethyltrichlorosilane, octadecyltrichlorosilane, hexamethyldisilazane, or the like as a surface treating agent can also be suitably used as an undercoat agent layer.
As the resin component, for example, a resin containing a resin having each constitutional unit constituting the block (b1) or the block (b2), and a resin having a constitutional unit having high affinity for each block constituting the component (BCP) are exemplary examples.
As the resin component for the undercoat agent, for example, it is preferable to use a compound or resin including both a site having high affinity for styrene such as an aromatic ring and a site having high affinity for methyl methacrylate (a highly polar functional group and the like).
As the resin component including both the site having high affinity with styrene and the site having high affinity with methyl methacrylate, for example, for example, a resin obtained by polymerizing at least, as monomers, a monomer having an aromatic ring and a monomer having a highly polar functional group is an exemplary example. As the monomer having an aromatic ring, a monomer having an aryl group obtained by removing a hydrogen atom from an aromatic hydrocarbon ring, such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group, or having a heteroaryl group in which carbon atoms constituting the ring of these groups are partially substituted with a heteroatom such as an oxygen atom, a sulfur atom, and a nitrogen atom is an exemplary example. In addition, as the monomer having a highly polar functional group, a monomer having a trimethoxysilyl group, a trichlorosilyl group, an epoxy group, a glycidyl group, a carboxy group, a hydroxy group, a cyano group, a hydroxyalkyl group in which the hydrogen atoms of the alkyl group are partially substituted with a hydroxyl group, and the like is an exemplary example.
In addition, as the compound including both the site having high affinity with styrene and the site having high affinity with methyl methacrylate, a compound including both an aryl group such as phenethyltrichlorosilane and a highly polar functional group, a compound including both an alkyl group such as an alkylsilane compound and a highly polar functional group, and the like are exemplary examples.
As the resin component for the undercoat agent, for example, a resin having both styrene and methyl methacrylate as constitutional units, and a resin having all of styrene, methyl methacrylate, and (hydroxyethyl) methacrylate as constituent units are exemplary examples.
In a case where the resin composition for the undercoat agent has two or more different constitutional units, as the resin, a random copolymer, an alternating polymer of styrene and methyl methacrylate (polymer obtained by alternately copolymerizing each monomer), and the like are exemplary examples.
The undercoat agent can be produced by dissolving the above-described resin component in a solvent.
As such a solvent, any solvent may be used as long as it can dissolve each component to be used and form a homogeneous solution. For example, the same solvent as the organic solvent component exemplary described in the resin composition for forming an etching mask pattern according to the above-described embodiment is an exemplary example.
The type of the support 1 is not particularly limited as long as the resin composition can be applied onto its surface. For example, a substrate made of an inorganic material such as a metal (silicon, copper, chromium, iron, and aluminum), glass, titanium oxide, silica or mica; a substrate made of an oxide such as SiO2; a substrate made of a nitride such as SiN; a substrate made of an oxynitride such as SiON; and a substrate made of an organic material such as acryl, polystyrene, cellulose, cellulose acetate, phenolic resin, and the like are exemplary examples. Among these, a metal substrate is suitable, and for example, a structure body having a cylinder structure or a lamellar structure vertically oriented is likely to be formed in a silicon substrate (Si substrate) or a copper substrate (Cu substrate). Among these, an Si substrate is particularly suitable.
The size and shape of the support 1 are not particularly limited. The support 1 is not necessarily required to have a smooth surface, and substrates of various shapes can be appropriately selected. For example, a substrate having a curved surface, a flat plate having a surface with an uneven shape, and a substrate with a flaky shape or the like are exemplary examples.
An inorganic and/or organic film may be provided on the surface of the support 1.
As the inorganic film, an inorganic antireflection film (inorganic BARC) is an exemplary example. As the organic film, an organic antireflection film (organic BARC) is an exemplary example.
The inorganic film can be formed, for example, by applying an inorganic antireflection film composition such as a silicon-based material onto a support and by sintering the film.
For example, the organic film can be formed by applying a material for forming an organic film, in which a resin component and the like constituting the film are dissolved in an organic solvent, onto a substrate using a spinner or the like, and baking the film under heating conditions at preferably 200° C. to 300° C. for preferably 30 to 300 seconds and more preferably 60 to 180 seconds. The material for forming an organic film does not necessarily need to have sensitivity to light or electron beams, which is essential for a resist film, and may have sensitivity or does not have to have sensitivity. Specifically, a resist or a resin generally used for the production of semiconductor elements or liquid crystal display elements can be used.
In addition, it is preferable that the material for forming an organic film is a material capable of forming an organic film which can be subjected to etching, particularly dry etching, so that the organic film can be etched by using a pattern formed from a block copolymer, which is formed by processing the BCP layer 3, to transfer the pattern onto the organic film, and an organic film pattern can be formed. Above all, the material for forming an organic film is preferably a material capable of forming an organic film capable of being subjected to etching such as oxygen plasma etching. Such a material for forming an organic film may be a material conventionally used for forming an organic film such as organic BARC. For example, ARC series manufactured by Nissan Chemical Industries, Ltd., AR series manufactured by Rohm and Haas Company, SWK series manufactured by Tokyo Ohka Kogyo Co., Ltd., and the like are exemplary examples.
A method of forming the undercoat agent layer 2 by applying the undercoat agent onto the support 1 is not particularly limited, and the undercoat agent layer 2 can be formed by a known method in the related art.
For example, the undercoat agent layer 2 can be formed by applying the undercoat agent onto the support 1 by a known method in the related art, such as using a spin coating or a spinner, to form a coating film, and drying the coating film.
As a method of drying the coating film, any method of drying the coating film may be used as long as the solvent contained in the undercoat agent can be volatilized, and for example, a method of baking the coating film is an exemplary example. In this case, a baking temperature is preferably 80° C. to 300° C., more preferably 180° C. to 270° C., and still more preferably 220° C. to 270° C. A baking time is preferably 30 to 500 seconds and more preferably 60 to 400 seconds.
A thickness of the undercoat agent layer 2 after drying the coating film is preferably approximately 10 to 100 nm and more preferably approximately 20 to 50 nm.
The surface of the support 1 may be cleaned in advance before forming the undercoat agent layer 2 on the support 1. Coatability of the undercoat agent is improved by cleaning the surface of the support 1.
Regarding the cleaning treatment method, known methods in the related art can be utilized, and an oxygen plasma treatment, an ozone oxidation treatment, an acid alkali treatment, a chemical modification treatment, and the like are exemplary examples.
After the undercoat agent layer 2 is formed, the undercoat agent layer 2 may be rinsed as necessary using a rinse liquid such as a solvent. Since uncrosslinked portions and the like in the undercoat agent layer 2 are removed by this rinsing, the affinity with at least one block constituting the block copolymer is improved, and a phase-separated structure including a cylinder structure or a lamellar structure, oriented in a direction perpendicular to the surface of the support 1, is likely to be formed.
The rinse liquid may be any one which can dissolve the uncrosslinked portions, and a solvent such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), or ethyl lactate (EL), or a commercially available thinner liquid can be used.
In addition, after the cleaning, post-baking may be performed in order to volatilize the rinse liquid. A temperature condition of the post-baking is preferably 80° C. to 250° C., more preferably 80° C. to 200° C., and still more preferably 80° C. to 150° C. A baking time is preferably 30 to 500 seconds and more preferably 60 to 240 seconds. A thickness of the undercoat agent layer 2 after the post-baking is preferably approximately 1 to 10 nm and more preferably approximately 2 to 7 nm.
Next, the layer 3 (BCP layer) containing the component (BCP) is formed on the undercoat agent layer 2.
The method of forming the BCP layer 3 on the undercoat agent layer 2 is not particularly limited, and a method of applying the resin composition for forming an etching mask pattern according to the above-described embodiment onto the undercoat agent layer 2 by a known method in the related art, such as spin coating or using a spinner, to form a coating film, and drying the coating film is an exemplary example.
A thickness of the BCP layer 3 may be a sufficient thickness for use as an etching mask and for phase separation to occur.
The film thickness of the BCP layer 3 is 25 nm or more, and may be 28 nm or more, 30 nm or more, 32 nm or more, 34 nm or more, or 36 nm or more. In a case where the film thickness is equal to or more than the above-described lower limit value, the phase-separated structure formed from the BCP layer 3 is likely to remain during etching and is likely to function as a mask.
The film thickness of the BCP layer 3 may be 100 nm or less, 75 nm or less, 50 nm or less, or 45 nm or less. In a case where the film thickness is equal to or less than the above-described upper limit value, it is easy to obtain a phase-separated structure having a desired periodic size, and it is easy to improve uniformity of the nano-structure body.
The film thickness of the BCP layer 3 is preferably 25 to 100 nm. For example, in a case where the support 1 is an Si substrate, the thickness of the BCP layer 3 is preferably adjusted to 25 to 100 nm and more preferably 30 to 75 nm.
In the step (ii), the BCP layer 3 formed on the support 1 is phase-separated.
By heating the support 1 after the step (i) to perform an annealing treatment, a phase-separated structure is formed such that at least a portion of the surface of the support 1 is exposed by selective removal of the block copolymer. That is, the structure body 3′ including a phase-separated structure which is phase-separated into a phase 3a and a phase 3b is produced on the support 1.
The annealing treatment is preferably performed under a temperature condition of equal to or higher than a glass transition temperature of the component (BCP) used and lower than a thermal decomposition temperature thereof. For example, in a case where the block copolymer is a polystyrene-poly(methyl methacrylate) (PS-PMMA) block copolymer (mass-average molecular weight: 5,000 to 100,000), the temperature is preferably 180° C. to 270° C. The heating time is preferably 30 to 3600 seconds.
In addition, it is preferable that the annealing treatment is performed in a gas having low reactivity, such as nitrogen.
Step (iii)
In the step (iii), a phase consisting of at least one block of the first block or the second block constituting the above-described component (BCP) is selectively removed from the structure body 3′. As a result, a fine pattern (polymer nano-structure body) is formed, and an etching mask pattern is obtained.
As a method of selectively removing the phase including the block, a method of performing an oxygen plasma treatment on the BCP layer, a method of performing a hydrogen plasma treatment on the BCP layer, and the like are exemplary examples.
For example, after the BCP layer containing the above-described component (BCP) is phase-separated, the BCP layer is subjected to an oxygen plasma treatment, a hydrogen plasma treatment, or the like, so that the phase including the block (b1) is not selectively removed, and the phase including the block (b2) is selectively removed.
In the embodiment shown in
The support 1 having the patterns formed by the phase separation of the BCP layer 3 consisting the component (BCP) as described above can be used as it is, but the shape of the pattern (polymer nano-structure body) of the support 1 may be changed by further heating.
Regarding the temperature conditions for the heating, it is preferable that the annealing treatment is performed at a temperature equal to or higher than a glass transition temperature of the block copolymer used and lower than a thermal decomposition temperature. In addition, the heating is preferably performed in a gas having low reactivity, such as nitrogen.
In the method for manufacturing an etching mask pattern according to the present embodiment, by using a resin composition for forming an etching mask pattern as described below, a phase-separated structure vertically oriented can be formed even with a film thickness of 25 nm or more. Hereinafter, the resin composition for forming an etching mask pattern will be described in detail.
The resin composition for forming an etching mask pattern used in the method for manufacturing an etching mask pattern according to the present embodiment contains a block copolymer having a first block and a second block. The first block is composed of a polymer consisting of a repeating structure of a constitutional unit represented by General Formula (b1). The second block is composed of a random copolymer consisting of a structure in which a constitutional unit represented by General Formula (b2m) and a constitutional unit represented by General Formula (b2g) are arranged in a disordered manner. A proportion of a volume of the first block to the total volume of the first block and the second block is 20% to 80% by volume.
The block copolymer is a polymer in which a plurality of types of blocks (partial structural components in which constitutional units of the same type are repeatedly bonded) are bonded. The blocks constituting the block copolymer may be two types or may be three or more types.
The block copolymer (hereinafter, also referred to as “component (BCP)”) in the present embodiment has a first block and a second block.
The first block is composed of a polymer consisting of a repeating structure of a constitutional unit represented by General Formula (b1) (hereinafter, also referred to as a constitutional unit (b1)).
[in the formula, R1 is an alkyl group which may have an oxygen atom or a silicon atom, n is an integer of 0 to 5, in a case where n is an integer of 2 or more, a plurality of R1's may be the same or different from each other, and Rb1 is a hydrogen atom or a methyl group]
In Formula (b1), R1 is an alkyl group which may have an oxygen atom or a silicon atom. In a case where the alkyl group of R1 has a silicon atom, the silicon atom may be a substituent which substitutes a methylene group (—CH2—) in the alkyl group. In a case where the alkyl group of R1 has an oxygen atom, the oxygen atom may be a substituent which substitutes a methylene group (—CH2—) in the alkyl group. The alkyl group preferably has 1 to 5 carbon atoms, more preferably has 1 to 4 carbon atoms, still more preferably has 1 to 3 carbon atoms, is particularly preferably an ethyl group or a methyl group and is most preferably a methyl group.
In Formula (b1), Rb1 is a hydrogen atom or a methyl group.
In Formula (b1), n is preferably 0 to 3, more preferably 0 to 2, and still more preferably 0 or 1.
The second block is composed of a random copolymer consisting of a structure in which a constitutional unit represented by General Formula (b2m) (hereinafter, also referred to as a constitutional unit (b2m)) and a constitutional unit represented by General Formula (b2g) (hereinafter, also referred to as a constitutional unit (b2g)) are arranged in a disordered manner.
The constitutional unit (b2m) is a constitutional unit represented by General Formula (b2m).
In Formula (b2m), Rb2 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. As the alkyl group having 1 to 5 carbon atoms as Rb2, a linear or branched alkyl group having 1 to 5 carbon atoms is preferable, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like are exemplary examples. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part of or all hydrogen atoms in the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. The halogen atom is particularly preferably a fluorine atom.
Rb2 is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms; and from the viewpoint of industrial availability, more preferably a hydrogen atom or a methyl group and still more preferably a methyl group.
Constitutional Unit (b2g)
The constitutional unit (b2g) is a constitutional unit represented by General Formula (b2g).
In Formula (b2g), Rb2 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The Rb2 is the same as Rb2 in Formula (b2m) described above.
In Formula (b2g), R2 is an alkyl group which may have a silicon atom, a fluorine atom, a carboxy group, an amino group, a cyano group, a hydroxy group, or a phosphoric acid group. The above-described alkyl group may be linear or branched, or may include a ring structure. The above-described alkyl group is preferably a linear, branched, or cyclic alkyl group, and more preferably a linear or cyclic alkyl group.
In a case where the above-described alkyl group is linear, it is sufficient that the number of carbon atoms therein is 1 or more, preferably 2 or more. The upper limit of the number of carbon atoms in the above-described linear alkyl group is not particularly limited, but from the viewpoint of phase separation performance, it is preferably 15 or less, more preferably 10 or less, still more preferably 8 or less, and particularly preferably 6 or less.
In a case where the above-described alkyl group is branched, it is sufficient that the number of carbon atoms therein is 3 or more. The upper limit of the number of carbon atoms in the above-described branched alkyl group is not particularly limited, but from the viewpoint of phase separation performance, it is preferably 15 or less, more preferably 10 or less, still more preferably 8 or less, and particularly preferably 6 or less. The number of carbon atoms in the above-described alkyl group is preferably 2 to 15, more preferably 2 to 10, still more preferably 2 to 8, even more preferably 2 to 6, and particularly preferably 2 to 5.
In a case where the above-described alkyl group has a ring structure, R2 may be a cycloalkyl group, may be a group in which a cycloalkylene group is interposed in the middle of a linear or branched alkyl group, or may be a group in which a cycloalkyl group is bonded to a terminal of a linear or branched alkylene group. The above-described cycloalkyl group and cycloalkylene group may be a monocyclic group or a polycyclic group, but are preferably a monocyclic group. In a case where the above-described cycloalkyl group or the above-described cycloalkylene group is a monocyclic group, the number of ring members is preferably 3 to 8, more preferably 3 to 6, and still more preferably 5 or 6. In a case where the above-described alkyl group includes a ring structure, it is sufficient that R2 has 3 or more carbon atoms. The upper limit of the number of carbon atoms in the above-described alkyl group including a ring structure is not particularly limited, but from the viewpoint of phase separation performance, it is preferably 15 or less, more preferably 10 or less, still more preferably 8 or less, and even more preferably 6 or less.
The number of carbon atoms in the alkyl group as R2 is preferably 2 to 15, more preferably 2 to 10, still more preferably 2 to 8, and even more preferably 2 to 6.
The alkyl group as R2 is preferably a linear alkyl group or cycloalkyl group having 2 to 6 carbon atoms.
The alkyl group as R2 may have a silicon atom, a fluorine atom, a carboxy group, an amino group, a cyano group, a hydroxy group, or a phosphoric acid group. In a case where the alkyl group as R2 has a fluorine atom, a carboxy group, an amino group, a cyano group, a hydroxy group, or a phosphoric acid group, the fluorine atom, carboxy group, amino group, cyano group, hydroxy group, or phosphoric acid group may be a substituent which substitutes a hydrogen atom of the alkyl group. The number of hydrogen atoms substituted in the above-described group is not particularly limited, but is preferably 1 to 3.
In a case where the alkyl group of R2 has a silicon atom, the silicon atom may be a substituent which substitutes a methylene group (—CH2—) in the alkyl group. The number of methylene groups substituted with the silicon atom is not particularly limited, but is preferably 1.
R2 is preferably an alkyl group which may be substituted with an alkylsilyl group, a fluoromethyl group, a carboxy group, an amino group, a hydroxy group, or a phosphoric acid group. The alkyl group in the above-described alkylsilyl group preferably has 1 to 3 carbon atoms and more preferably has 1 or 2 carbon atoms. The above-described alkylsilyl group is preferably a trialkylsilyl group, more preferably a triethylsilyl group or a trimethylsilyl group, and still more preferably a trimethylsilyl group. The above-described fluoromethyl group is preferably a trifluoromethyl group.
Preferred examples of R2 in a case where R2 is a linear alkyl group having a substituent are shown below, but the present invention is not limited thereto. In the formulae, * is a bonding site bonding to a sulfur atom(S) in Formula (b2g).
[in the formulae, Y2 is a single bond or a linear or branched alkylene group having 1 to 15 carbon atoms, and p is an integer of 1 to 10]
In Formulae (r2-1) to (r2-8), Y2 is a single bond or a linear or branched alkylene group having 1 to 15 carbon atoms.
In a case where the above-described alkylene group is linear, the number of carbon atoms in the linear alkylene group is more preferably 1 to 10, still more preferably 1 to 8, and particularly preferably 1 to 5. In a case where the above-described alkylene group is branched, the number of carbon atoms in the branched alkylene group is more preferably 2 to 10, still more preferably 2 to 8, and particularly preferably 2 to 6.
The alkylene group as Y2 is preferably a linear alkylene group having 1 to 5 carbon atoms or a branched alkylene group having 2 to 6 carbon atoms.
In a case where R2 is a group represented by any one of Formulae (r2-1) to (r2-8), Y2 is preferably a linear or branched alkylene group having 1 to 15 carbon atoms, and more preferably a linear alkylene group having 1 to 5 carbon atoms or a branched alkylene group having 2 to 6 carbon atoms. In a case where R2 is a group represented by Formula (r2-9), Y2 is preferably a single bond or a linear alkylene group having 1 to 5 carbon atoms, and more preferably a single bond.
In General Formula (r2-9), p is preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and still more preferably 3 or 4.
Specific examples of R2 are shown below, but it is not limited thereto. In the formulae, * is a bonding site bonding to a sulfur atom(S) in Formula (b2g).
[in the formulae, q is an integer of 1 to 15, q′ is an integer of 0 to 15, p is an integer of 1 to 10, and p′ is each independently an integer of 0 to 10]
In the formulae, q is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, and particularly preferably 1 to 5.
In Formulae (r2-18) and (r2-19), q′ is preferably 0 to 10, more preferably 0 to 8, still more preferably 0 to 6, and particularly preferably 0 to 5.
In Formula (r2-18), p is preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and still more preferably 3 or 4.
In Formula (r2-19), p′ is preferably an integer of 1 to 8, more preferably an integer of 1 to 6, still more preferably an integer of 1 to 3, and particularly preferably 1 or 2.
In Formula (b2g), R3 is a linear or branched alkylene group having 1 to 10 carbon atoms, which may have a hydroxy group. In a case where the above-described alkylene group is linear, it is sufficient that the number of carbon atoms therein is 1 or more, preferably 3 or more. From the viewpoint of phase separation performance, the upper limit of the number of carbon atoms in the above-described linear alkylene group is preferably 8 or less, more preferably 5 or less, and still more preferably 4 or less. The number of carbon atoms in the above-described linear alkylene group is particularly preferably 3. In a case where the above-described alkylene group is branched, it is sufficient that the number of carbon atoms therein is 3 or more, preferably 4 or more. From the viewpoint of phase separation performance, the upper limit of the number of carbon atoms in the above-described branched alkylene group is preferably 8 or less, and more preferably 5 or less. The number of carbon atoms in the above-described alkylene group is preferably 3 to 10, more preferably 3 to 8, still more preferably 3 to 5, even more preferably 3 or 4, and particularly preferably 3.
The alkylene group as R3 is preferably a linear alkylene group having 3 carbon atoms.
The alkylene group as R3 may have a hydroxy group. The above-described hydroxy group may be a substituent which substitutes a hydrogen atom of the alkylene group. The number of hydrogen atoms substituted by the hydroxy group is not particularly limited, but is preferably 1 to 3, more preferably 1 or 2, and still more preferably 1.
The constitutional unit (b2g) is preferably a constitutional unit represented by General Formula (b2g-1).
[in the formula, R4 is a hydrogen atom or a hydroxy group, k1 and k2 are each independently an integer of 1 to 5, and Rb2 and R2 are the same as Rb2 and R2 in Formula (b2g) described above]
In Formula (b2g-1), Rb2 and R2 are the same as Rb2 and R2 in Formula (b2g) described above. R2 is preferably represented by Formulae (r2-1) to (r2-9) and more preferably represented by Formulae (r2-10) to (r2-19).
In Formula (b2g-1), R4 is a hydrogen atom or a hydroxy group.
In Formula (b2g-1), k1 and k22 are each independently an integer of 1 to 5. k1 and k2 are preferably 1 to 3, more preferably 1 or 2, and still more preferably 1.
Specific examples of the constitutional unit (b2g) are shown below, but it is not limited thereto. In the formulae, R represents a methyl group or a hydrogen atom, and a methyl group is preferable.
The second block is composed of a random copolymer consisting of a structure in which the above-described constitutional unit (b2g) and the above-described constitutional unit (b2m) are arranged in a disordered manner. In Formulae (b2g) and (b2m), x and 1−x represent a molar ratio of the constitutional unit (b2g) and the constitutional unit (b2m). x is more than 0 and 0.10 or less. x is preferably less than 0.10, more preferably 0.09 or less, still more preferably 0.08 or less, and particularly preferably 0.07 or less. x is preferably 0.0050 or more, more preferably 0.0070 or more, still more preferably 0.0090 or more, particularly preferably 0.0095 or more, and most preferably 0.0099 or more.
In a case where x is equal to or more than the above-described lower limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more. In a case where x is equal to or less than the above-described upper limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more.
In the component (BCP), the proportion of the volume of the first block to the total volume of the first block and the second block is 20% to 80% by volume. The proportion of the volume of the first block is preferably 30% by volume or more, and more preferably 35% by volume or more. The upper limit value of the proportion of the volume of the first block is preferably 70% by volume or less, more preferably 65% by volume or less, and still more preferably 60% by volume or less.
The proportion of the volume of the first block to the total volume of the first block and the second block in the component (BCP) can be obtained as follows.
From an analysis result of 1H NMR, mol % of each of the first block and the second block in the component (BCP) is calculated, and % by mass of each block is calculated from a molecular weight of each block. The % by mass of each block is divided by a density of each block to calculate a ratio of volume of each block, and % by volume of the first block in the component (BCP) is calculated from the ratio of volume. The density of each block can be estimated by the atomic group contribution method (Fedors, R.F. Polym. Eng. Sci. 1974, 14, pp. 147 to 154). In a case where the first block is a polystyrene block (PS), 1.05 g·m−3 can be used as a density of PS. In a case where the second block is a polystyrene block (PS), 1.05 g·m−3 can be used as a density of PS. In a case where the second block has a constitutional unit induced from methyl methacrylate, 1.18 g·cm−3 can be used as a density of a structure constituting the constitutional unit. In a case where the second block has a constitutional unit induced from 2-hydroxy-3-(2,2,2-trifluoroethylsulfanyl) propyl methacrylate, 1.43 g·cm-3 can be used as a density of a structure constituting the constitutional unit. In a case where the second block has a constitutional unit derived from 2-hydroxy-3-(ethylsulfanyl) propyl methacrylate, 2-hydroxy-3-(1-propyl) propyl methacrylate, 2-hydroxy-3-(1-hexyl) propyl methacrylate, or 2-hydroxy-3-(cyclohexyl) propyl methacrylate, 1.18 g·cm−3 can be used as a density of a structure composed of the constitutional unit.
As for the density of each block, densities described in documents (Polymer Handbook, 4th ed.; Wiley: New York, 2004) and the like can also be used.
The component (BCP) may have other blocks in addition to the first block and the second block. As a preferred aspect, the component (BCP) is a block copolymer composed of the first block and the second block.
A number-average molecular weight (Mn) (in terms of polystyrene according to size-exclusion chromatography) of the component (BCP) is not particularly limited, but is preferably 3,000 to 100,000, more preferably 5,000 to 50,000, still more preferably 6,000 to 40,000, and particularly preferably 8,000 to 30,000.
A polydispersity (Mw/Mn) of each block constituting the component (BCP) is preferably 1.0 to 1.5, more preferably 1.0 to 1.4, and still more preferably 1.0 to 1.3.
The above-described resin composition for forming an etching mask pattern can be prepared by dissolving the above-described component (BCP) in an organic solvent component.
Any organic solvent component may be used as long as it can dissolve each component to be used and form a homogeneous solution, and arbitrary solvents may be selected from any solvents known in the related art as a solvent for a film composition containing a resin as a main component.
As the organic solvent component, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; polyhydric alcohol derivatives such as compounds having an ether bond, for example, a monoalkylether such as monomethylether, monocthylether, monopropylether, or monobutylether or monophenylether of any of the polyhydric alcohols or the compounds having an ester bond [among these, propylene glycol monomethyl ether acetate (PGMEA), or propylene glycol monomethyl ether (PGME) is preferable]; cyclic ethers such as dioxane; esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethylbenzylether, cresylmethylether, diphenylether, dibenzylether, phenetole, butylphenylether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene; and the like are exemplary examples.
The organic solvent component may be used alone or as a mixed solvent of two or more kinds thereof. Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, or EL is preferable.
In addition, a mixed solvent obtained by mixing PGMEA with a polar solvent is also preferable. A blending ratio (mass ratio) of the mixed solvent can be appropriately determined in consideration of compatibility between PGMEA and the polar solvent, and it is preferably in a range of 1:9 to 9:1 and more preferably in a range of 2:8 to 8:2.
For example, in a case where EL is blended as the polar solvent, a mass ratio of PGMEA: EL is preferably 1:9 to 9:1 and more preferably 2:8 to 8:2. In addition, in a case where PGME is blended as the polar solvent, a mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and still more preferably 3:7 to 7:3. In addition, in a case where PGME and cyclohexanone are blended as the polar solvent, a mass ratio of PGMEA:(PGME+cyclohexanone) is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and still more preferably 3:7 to 7:3.
In addition, as the organic solvent component in the resin composition for forming an etching mask pattern, in addition to those solvents, a mixed solvent in which PGMEA, EL, or the above-described mixed solvent of PGMEA and a polar solvent is mixed with γ-butyrolactone is also preferable. In this case, as a mixing proportion, a mass ratio of the former and the latter is preferably set to 70:30 to 95:5.
The concentration of the organic solvent component contained in the resin composition for forming an etching mask pattern is not particularly limited, and the component is appropriately set at a concentration with which the coating can be performed according to the coating film thickness. A concentration of solid contents is generally used in a range of 0.2% to 70% by mass, preferably in a range of 0.2% to 50% by mass.
In addition to the above-described component (BCP) and organic solvent component, the above-described resin composition for forming an etching mask pattern may further contain, as desired, a miscible additive such as an additional resin for improving the performance of the layer, a surfactant for improving coatability, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, a halation inhibitor, a dye, a sensitizer, a base promoter, and a basic compound.
With the method for manufacturing an etching mask pattern according to the embodiment described above, since the above-described resin composition for forming an etching mask pattern according to the embodiment is used, it is possible to form a phase-separated structure having vertical orientation even with a film thickness of a layer containing a block copolymer of 25 nm or more. By selectively removing a specific phase of the vertically oriented BCP layer, an etching mask can be obtained. Since the etching mask obtained in this way has a film thickness of 25 nm or more, the etching mask is likely to remain during etching, and etching resistance is likely to be increased.
In addition, according to the method for manufacturing an etching mask pattern according to the embodiment, it is possible to manufacture a support having a nano-structure body in which position and orientation are more freely designed on the support surface. For example, the formed structure body has high adhesiveness to the support and tends to have a phase-separated structure having a cylinder structure or a lamellar structure, oriented in the direction perpendicular to the surface of the support.
In the method for manufacturing an etching mask pattern according to the present embodiment, a step of providing a guide pattern on the undercoat agent layer (guide pattern forming step) may be provided before the step (i) described above. As a result, it is possible to control an array structure of the phase-separated structure. That is, the resin composition for forming an etching mask pattern may be applied onto the undercoat agent layer on which the guide pattern has been formed.
For example, in a case where the guide pattern is not provided, even for a block copolymer with which a random fingerprint-shaped phase-separated structure is formed, in a case where a groove structure of a resist film is provided on the surface of the undercoat agent layer, a phase-separated structure oriented along the grooves is obtained. According to such a principle, the guide pattern may be provided on the undercoat agent layer 2. In addition, in a case where a surface of the guide pattern has an affinity with any of the blocks constituting the above-described component (BCP), a phase-separated structure including a cylinder structure or a lamellar structure, which is oriented in the direction perpendicular to the surface of the support, is likely to be formed.
The guide pattern can be formed, for example, using a resist composition.
As the resist composition for forming the guide pattern, among resist compositions and modified products thereof, which are generally used for formation of a resist pattern, any one having the affinity with any of the blocks constituting the above-described component (BCP) can be appropriately selected and used. The resist composition may be any of a positive-type resist composition for forming a positive-tone pattern in which the exposed part of the resist film is dissolved and removed, or a negative-tone resist composition for forming a negative-type pattern in which the unexposed part of the resist film is dissolved and removed; but the resist composition is preferably a negative-type resist composition. As the negative-type resist composition, for example, a resist composition containing an acid generator, and a base material component in which solubility in a liquid developer containing an organic solvent is decreased by the action of an acid, and in which the base material component contains a resin component having a constitutional unit which is decomposed by the action of an acid to have increased polarity, is preferable.
After the BCP composition is poured on the undercoat agent layer on which the guide pattern has been formed, an annealing treatment is performed to induce phase separation. Therefore, the resist composition for forming the guide pattern is preferably a composition capable of forming a resist film having excellent solvent resistance and heat resistance.
As the resin composition for forming an etching mask pattern according to the present embodiment, those described in the embodiment above are exemplary examples. The block copolymer (the component (BCP)) in the resin composition for forming an etching mask pattern can be produced by, for example, a production method including the following steps.
Step (p1): step of obtaining a block copolymer having the first block and a precursor of the second block (hereinafter, also referred to as “BCP precursor”)
Step (p2): step of obtaining a block copolymer (component (BCP)) containing the first block and the second block by reacting the precursor of the second block in the BCP precursor with a compound represented by R2—SH (R2 is the same as R2 in Formula (b2g) described above)
The precursor of the second block is a random copolymer consisting of a structure in which a constitutional unit (b2gp) that is a precursor of the constitutional unit (b2g) and the constitutional unit (b2m) are arranged in a disordered manner. The constitutional unit (b2gp) is a constitutional unit including an epoxy group or a vinyl group, and a constitutional unit represented by General Formula (b2gp) is an exemplary example.
[in the formulae, Rb2 and x are the same as Rb2 and x in Formula (b2g) and Formula (b2m) described above, Yp2 represents a linear or branched alkyl group having 1 to 8 carbon atoms, and Rp2 represents an epoxy group or a vinyl group]
In Formulae (b2gp) and (b2m), x and 1−x represent a molar ratio of the constitutional unit (b2gp) and the constitutional unit (b2m). x is more than 0 and 0.10 or less. x is preferably less than 0.10, more preferably 0.09 or less, still more preferably 0.08 or less, and particularly preferably 0.07 or less. x is preferably 0.0050 or more, more preferably 0.0070 or more, still more preferably 0.0090 or more, particularly preferably 0.0095 or more, and most preferably 0.0099 or more.
In a case where x is equal to or more than the above-described lower limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more. In a case where x is equal to or less than the above-described upper limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more.
The BCP precursor can be obtained by, for example, performing a polymerization reaction of a monomer for inducing the constitutional unit (b1) (for example, styrene or a derivative thereof; hereinafter, the monomer is also referred to as a monomer (b1)), and then performing the polymerization reaction by adding a monomer for inducing the constitutional unit (b2gp) (for example, glycidyl methacrylate, allyl methacrylate, and the like; hereinafter, the monomer is also referred to as a monomer (b2gp)) and a monomer for inducing the constitutional unit (b2m) (for example, methyl methacrylate; hereinafter, the monomer is also referred to as a monomer (b2m)) to the polymerization reaction solution. Alternatively, the BCP precursor can be obtained by performing a polymerization reaction with a mixture of the monomer (b2gp) and the monomer (b2m), and then performing the polymerization reaction by adding the monomer (b1) to the polymerization reaction solution. As the polymerization reaction, living polymerization is preferable because it is easy to synthesize with narrow dispersion. As a preferred living polymerization method, living anionic polymerization and living radical polymerization are exemplary examples, and living anionic polymerization is particularly preferable because the narrow dispersion can be further achieved.
In the step of producing the random copolymer consisting of the constitutional unit (b2gp) and the constitutional unit (b2m), a proportion of the number of moles of the monomer (b2gp) in the mixture of the monomer (b2gp) and the monomer (b2m) is more than 0 and 0.10 or less with respect to the total number of moles of the monomer (b2gp) and the monomer (b2m). The proportion of the number of moles of the monomer (b2gp) is preferably less than 0.10, more preferably 0.09 or less, still more preferably 0.08 or less, and particularly preferably 0.07 or less. The proportion of the number of moles of the monomer (b2gp) is preferably 0.0050 or more, more preferably 0.0070 or more, still more preferably 0.0090 or more, particularly preferably 0.0095 or more, and most preferably 0.0099 or more.
In a case where the proportion of the number of moles of the monomer (b2gp) is equal to or more than the above-described lower limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more. In a case where the proportion of the number of moles of the monomer (b2gp) is equal to or less than the above-described upper limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more.
In the step of producing the random copolymer consisting of the constitutional unit (b2gp) and the constitutional unit (b2m), a proportion of the number of moles of the monomer (b2m) in the mixture of the monomer (b2gp) and the monomer (b2m) is 0.90 or more and less than 1.0 with respect to the total number of moles of the monomer (b2gp) and the monomer (b2m). The proportion of the number of moles of the monomer (b2m) is preferably more than 0.90, more preferably 0.91 or more, still more preferably 0.92 or more, and particularly preferably 0.93 or more. The proportion of the number of moles of the monomer (b2m) is preferably 0.9950 or less, more preferably 0.9930 or less, still more preferably 0.9910 or less, particularly preferably 0.9905 or less, and more preferably 0.9901 or less.
In a case where the proportion of the number of moles of the monomer (b2m) is equal to or more than the above-described lower limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more. In a case where the proportion of the number of moles of the monomer (b2m) is equal to or less than the above-described upper limit value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more.
In the step of producing the BCP precursor, a proportion of the number of moles of the monomer (b1) is preferably 0.25 to 4.0, more preferably 0.33 to 3.0, and still more preferably 0.5 to 2.0 with respect to the total number of moles of the monomer (b2gp) and the monomer (b2m).
In a case where the proportion of the number of moles of the monomer (b1) is within the above-described numerical value, a phase-separated structure vertically oriented is easily formed even with a film thickness of 25 nm or more.
The compound represented by R2—SH (hereinafter, also referred to as “compound (R2—SH)”) is a compound obtained by a reaction of an epoxy group or a vinyl group of the constitutional unit (b2gp) to convert the constitutional unit (b2gp) into the constitutional unit (b2g).
In a case where the constitutional unit (b2gp) includes an epoxy group, the reaction between the BCP precursor and the compound (R2—SH) can be performed in an organic solvent such as tetrahydrofuran in the presence of a catalyst such as lithium hydroxide. As a reaction temperature, for example, 20° C. to 60° C. are exemplary examples, and 30° C. to 50° C. are preferable and 35° C. to 45° C. are more preferable. A reaction time can be appropriately set according to the amount of the BCP precursor used, and may be sufficient to convert all the constitutional units (b2gp) in the precursor of the second block into the constitutional units (b2g). As a reaction time, for example, 1 to 10 hours are exemplary examples. In a case where the constitutional unit (b2gp) includes a vinyl group, the reaction between the BCP precursor and the compound (R2—SH) can be performed by a thiol-ene reaction. The thiol-ene reaction can be carried out in an organic solvent such as tetrahydrofuran in the presence of a catalyst such as azobisisobutyronitrile (AIBN). As a reaction temperature, for example, 60° C. to 90° C. are exemplary examples, and 70° C. to 90° C. are preferable and 75° C. to 85° C. are more preferable. A reaction time can be appropriately set according to the amount of the BCP precursor used, and may be sufficient to convert all the constitutional units (b2gp) in the precursor of the second block into the constitutional units (b2g). As a reaction time, for example, 1 to 10 hours are exemplary examples.
[in the Formulae, R1 and Rb1 are the same as R1 and Rb1 in Formula (b1) described above, n is the same as n in Formula (b1) described above, R2 and R3 are the same as R2 and R3 in Formula (b2g) described above, Rb2 and x are the same as Rb2 and x in Formula (b2g) and Formula (b2m) described above, Yp2 represents a linear or branched alkyl group having 1 to 8 carbon atoms, and Rp2 represents an epoxy group or a vinyl group]
With the resin composition for forming an etching mask pattern according to the present embodiment described above, it is possible to form a phase-separated structure vertically oriented even with a film thickness of a layer containing a block copolymer of 25 nm or more. Therefore, the phase-separated structure can be used as an etching mask.
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
All anionic polymerizations were carried out in an argon atmosphere. 30 mL of tetrahydrofuran (THF) and lithium chloride (LiCl) (21.2 mg, 0.500 mmol) were transferred into a 50 mL Schlenk tube and cooled to −78° C. in a Coolnics bath. Sec-butyllithium (Sec-BuLi) (1.05M hexane/cyclohexane solution) was added to the Schlenk tube until the color of the solution turned yellow. The Schlenk tube was removed from the Coolnics bath and warmed to room temperature until the colorless solution was obtained. The Schlenk tube was cooled again in a Coolnics bath to −78° C., and sec-BuLi (0.095 mL, 0.100 mmol) was added as an initiator. Styrene (0.977 mL, 8.50 mmol) was added thereto, and the mixture was stirred for 30 minutes. As a result, a bright orange colored solution was obtained. 1,1-diphenylethylene (DPE) (0.088 mL, 0.50 mmol) was added thereof, and the color of the solution turned deep red. After stirring for 30 minutes, a monomer mixture of methyl methacrylate (MMA) (0.730 mL, 6.85 mmol) and glycidyl methacrylate (GMA) (0.244 mL, 2.05 mmol) was added thereto, and the mixture was stirred for 30 minutes. The color of the solution turned from red to transparent. As a terminator, 3 mL of degassed methanol (MeOH) was added to the Schlenk tube to terminate the polymerization. The Schlenk tube was pulled up from the Coolnics bath, and the solution was introduced into MeOH to perform reprecipitation. The solid of the precipitate was filtered and then dried under reduced pressure at 40° C. to obtain a white powder of a BCP precursor (1) (1.86 g, 88% yield).
A BCP precursor (2) was synthesized in the same manner as in the synthesis of the BCP precursor (1) described above, except that the use amount of styrene was changed to 1.07 mL (9.29 mmol), the use amount of MMA was changed to 0.936 mL (8.79 mmol), and the use amount of GMA was changed to 0.117 mL (0.976 mmol).
A BCP precursor (3) was synthesized in the same manner as in the synthesis of the BCP precursor (1) described above, except that the use amount of styrene was changed to 1.15 mL (10.00 mmol), the use amount of MMA was changed to 1.03 mL (9.69 mmol), and the use amount of GMA was changed to 0.087 mL (0.729 mmol).
A BCP precursor (4) was synthesized in the same manner as in the synthesis of the BCP precursor (1) described above, except that the use amount of styrene was changed to 1.08 mL (9.42 mmol), the use amount of MMA was changed to 1.14 mL (10.72 mmol), and the use amount of GMA was changed to 0.067 mL (0.564 mmol).
A BCP precursor (5) was synthesized in the same manner as in the synthesis of the BCP precursor (1) described above, except that the use amount of styrene was changed to 1.30 mL (11.28 mmol), the use amount of MMA was changed to 1.37 mL (12.90 mmol), and the use amount of GMA was changed to 0.016 mL (0.130 mmol).
0.2 g of the BCP precursor (1) and THF (20 wt % solution) were placed into a 10 mL glass tube, and the mixture was immersed in an ice water tank. A 1 wt % lithium hydroxide (LiOH) aqueous solution (LiOH 0.05 molar equivalent/GMA unit) and 2,2,2-trifluoroethanethiol (2 molar equivalent/GMA unit) were added to the glass tube. After stirring the mixture at room temperature for 20 minutes, a reactor was set to 40° C., and the mixture was stirred for 3 hours to synthesize BCP (1). Residual reagents were removed by repeatedly performing precipitation with methanol or methanol/hexane several times, depending on the Mn and PHFMA fractions of the synthesized BCP (1). The product was dried under reduced pressure overnight at room temperature to obtain a white powder of the BCP (1). Mn and dispersity (PDI=Mw/Mn) of the BCP precursor (1), measured by size-exclusion chromatography (SEC), were 21,000 g·mol-1 and 1.03.
BCP (2) to (5) were each synthesized in the same manner as in the synthesis of BCP (1), except that the BCP precursors (2) to (5) were each used in place of the BCP precursor (1).
Mn and dispersity (PDI=Mw/Mn) of the BCP (2), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (3), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (4), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (5), measured by size-exclusion chromatography (SEC), were 25,000 g·mol−1 and 1.03.
The value of x in the obtained BCP (1) to (5) was the same as the proportion of the number of moles of GMA to the total number of moles of MMA and GMA used in the synthesis of the BCP precursor.
mol % of each block in the block copolymer was calculated from the result of 1H NMR analysis, and % by mass of each block was further calculated. Next, the % by mass of each block was divided by a density of each block to calculate a ratio of volume of each block. From the ratio of volume, a proportion of a volume of the polystyrene block to the total volume of the block copolymer was calculated. The density of each block was estimated by the atomic group contribution method (Fedors, R.F. Polym. Eng. Sci. 1974, 14, pp. 147 to 154). 1.05 g·m−3 was used as a density of the polystyrene block. 1.18 g·cm−3 was used as a density of a structure composed of the constitutional unit induced from methyl methacrylate. 1.43 g·cm−3 was used as a density of a structure composed of the constitutional unit induced from 2-hydroxy-3-(2,2,2-trifluoroethylsulfanyl) propyl methacrylate. 1.18 g·cm−3 was used as a density of a structure composed of the constitutional unit induced from 2-hydroxy-3-(ethylsulfanyl) propyl methacrylate, 2-hydroxy-3-(1-propyl) propyl methacrylate, 2-hydroxy-3-(1-hexyl) propyl methacrylate, or 2-hydroxy-3-(cyclohexyl) propyl methacrylate.
For each block copolymer synthesized as described above, the number-average molecular weight (Mn), the proportion (% by volume) of the volume of the polystyrene block (PS) to the total volume of the block copolymer, and the value of x in the reaction formula are summarized in Table 1.
Each component shown in Table 2 was mixed and dissolved in the organic solvent component to prepare a resin composition for forming an etching mask pattern (solid content concentration: 1.6% by mass) of each example. Polyethylene glycol monomethyl ether acetate (PGMEA) was used as the organic solvent component.
In Table 1, each abbreviation has the following meaning. A numerical value in the brackets is a blending amount (part by mass).
Using the resin composition for forming an etching mask pattern of each of Examples, a structure body including a phase-separated structure was obtained by a production method including the following step (i) to step (iii).
In order to prepare an undercoat agent, resins NL-(1) to NL-(4) for an undercoat agent were prepared. The NL-(1) to NL-(4) are all a random copolymer consisting of styrene, methyl methacrylate, and (hydroxyethyl) methacrylate.
Compositional ratios (proportion (molar ratio) of each constitutional unit in the structural formulae) of NL-(1) to NL-(4) (St/MMA/HEMA) were as follows. “St” means styrene, “MMA” means methyl methacrylate, and HEMA means (hydroxyethyl) methacrylate. The number-average molecular weight (Mn) and the water contact angle (W.C.A.) of NL-(1) to NL-(4) were as follows.
In NL-(1), St/MMA/HEMA was 39/56/5, Mn was 24,000, and W.C.A. was 72°.
In NL-(2), St/MMA/HEMA was 49/46/5, Mn was 28,000, and W.C.A. was 75°.
In NL-(3), St/MMA/HEMA was 61/34/5, Mn was 30,000, and W.C.A. was 77°.
In NL-(4), St/MMA/HEMA was 70/25/5, Mn was 29,000, and W.C.A. was 79°.
100 parts by mass of each of the resins NL-(1) to NL-(4) for an undercoat agent was mixed with and dissolved in 9,900 parts by mass of PGMEA to prepare undercoat agents NL-1 to NL-4.
A 12-inch silicon wafer was prepared as a support.
Any one of the undercoat agents NL-1 to NL-4 was spin-coated on a silicon substrate, and then heated in an air atmosphere at 250° C. for 5 minutes. An undercoat agent layer having a film thickness of 30 nm and formed of any one of the resins NL-(1) to NL-(4) for an undercoat agent was formed on a surface of the substrate.
Next, the undercoat agent layer was rinsed using a rinsing solution consisting of propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA) (PGME/PGMEA=7/3). Next, the undercoat agent layer was heated at 100° C. for 1 minute to volatilize the rinsing solution.
Next, the resin composition of each of Examples was spin-coated on the substrate such that the film thickness was 36 nm, thereby forming a resin composition layer (layer containing a block copolymer).
The resin composition layer formed on the above-described substrate was pre-baked at 90° C. for 60 seconds in a nitrogen atmosphere, and then annealed at 240° C. for 5 minutes in a nitrogen atmosphere to form a phase-separated structure.
Step (iii):
Oxygen plasma treatment (200 mL/min, 40 Pa, 40° C., 200 W, 10 seconds) was performed on the substrate on which the phase-separated structure had been formed using TCA-3822 (manufactured by TOKYO OHKA KOGYO CO., LTD.), and thus a PMMA phase was selectively removed.
With regard to the phase-separated structure on the surface of the obtained substrate, an SEM image was acquired at a magnification of 100,000 times using “CG6300” of Hitachi High-Tech Corporation. Next, analysis of the pattern period was performed from the SEM image using “Terminal PC software” of Hitachi High-Technologies Corporation. The results of the evaluation of the resolution are shown in Table 3.
In a case where the resin composition of Comparative Example 1 was used, since the phase-separated structure was not formed, the resolution could not be obtained. These are described as “-”
Margin of vertical orientation was evaluated using the undercoat agents NL-1 to NL-4.
The results of the evaluation of the margin of vertical orientation are shown in Table 3.
In Examples 1 to 4, the Evaluation of resolution was A.
In Examples 1 to 4, the results of the Evaluation of margin of vertical orientation were excellent as compared with Comparative Example 1.
Using the resin composition for forming an etching mask pattern of each of Examples, a structure body including a phase-separated structure was obtained by a production method including the following step (i) and step (ii).
Evaluation of vertical orientation was performed according to the evaluation method described in Evaluation 2. The results are shown in Table 4.
An undercoat agent layer was formed on a 12-inch silicon wafer using the NL-2 in the same manner as in Production of structure body including phase-separated structure of Evaluation 1. Next, after a guide pattern was formed, a structure body including a phase-separated structure was manufactured in the same manner as in Production of structure body including phase-separated structure of Evaluation 1.
An organic anti-reflective film composition “ARC-29A” (trade name, manufactured by Brewer Science, Inc.) was applied to a 12-inch silicon wafer using a spinner, and the composition was then baked and dried on a hotplate at 205° C. for 60 seconds, thereby forming an organic anti-reflective film with a film thickness of 89 nm. The undercoat agent NL-2 was spin-coated on the organic anti-reflective film and heated at 250° C. for 600 seconds. A thin film having a film thickness of 10 nm and formed of the resin NL-(2) for an undercoat agent was formed on a surface of the substrate. A resist film for forming a guide pattern was applied onto the film using a spinner, subjected to pre-bake treatment (PAB) on a hotplate, and dried to form a resist film for forming a guide pattern with a film thickness of 90 nm. Selective irradiation was performed using ArF excimer laser (193 nm) by an ArF exposure apparatus XT-1900Gi (manufactured by ASML) through a mask pattern. The resist film was subjected to post exposure bake (PEB) treatment, further developed with butyl acetate, and shaken off to dry. Next, post bake treatment was performed under conditions of 100° C. for 1 minute and then 200° C. for 5 minutes to form a guide pattern matching the space dimension five times a d value of the block copolymer used.
The surface (in the phase-separated state) of the obtained substrate was observed with a length-measuring SEM (scanning electron microscope, trade name: CG6300, manufactured by Hitachi High-Tech Corporation) to evaluate vertical orientation of the phase-separated structure. The results are shown in Table 4.
In Examples 1 to 4, the phase-separated structure having vertical orientation could be favorably formed as compared with Comparative Example 1.
Furthermore, BCP (6) to (25) were synthesized. Using these, a structure body including a phase-separated structure was produced by the same method as the above-described evaluation method of Evaluation 1 and Evaluation 2, and the obtained phase-separated structure was evaluated.
BCP (6) to (10) were synthesized by the same method as the method for synthesizing the BCP (1) to (5), except that ethanethiol was used instead of 2,2,2-trifluoroethanethiol for the above-described BCP precursors (1) to (5).
Mn and dispersity (PDI=Mw/Mn) of the BCP (6), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (7), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (8), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (9), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (10), measured by size-exclusion chromatography (SEC), were 25,000 g·mol−1 and 1.03.
The analysis result of the NMR measurement of the BCP (7) was as follows.
1H NMR (400 MHZ, CDCl3, δ, ppm): 0.85 to 1.02 (α-CH3, PMMA and PGEMA), 1.23 to 1.69 (—S—CH2—CH3—, PGEMA; —CH2—CH—, PS backbone), 1.74 to 2.02 (—CH2—CH—, PS backbone; —CH2—C(CH3)—, PGEMA and PMMA), 2.63 (—CH(OH)—CH2—S—CH2—CH3, PGEMA), 3.60 (—O—CH3, PMMA), 3.99 (—(C═O)O—CH2—CH(OH), PGEMA), 6.39 to 6.85 (o-aromatic, PS), 6.91 to 7.42 (p- and m-aromatic, PS)
BCP (11) to (15) were synthesized by the same method as the method for synthesizing the BCP (1) to (5), except that 1-propanethiol was used instead of 2,2,2-trifluoroethanethiol for the above-described BCP precursors (1) to (5).
Mn and dispersity (PDI=Mw/Mn) of the BCP (11), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (12), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (13), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (14), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (15), measured by size-exclusion chromatography (SEC), were 25,000 g·mol−1 and 1.03.
The analysis result of the NMR measurement of the BCP (12) was as follows.
1H NMR (400 MHZ, CDCl3, δ, ppm): 0.85 to 1.02 (α-CH3, PMMA and PGPMA; —S—CH2—CH2—CH3, PGPMA), 1.23 to 1.69 (—S—CH2—CH2—CH3, PGPMA; —CH2—CH—, PS backbone), 1.74 to 2.02 (—CH2—CH—, PS backbone; —CH2—C(CH3)—, PGPMA and PMMA), 2.63 (—CH(OH)—CH2—S—CH2—CH2—, PGPMA), 3.60 (—O—CH3, PMMA), 3.99 (—(C═O)O—CH2—CH(OH), PGPMA), 6.39 to 6.85 (o-aromatic, PS), 6.91 to 7.42 (p- and m-aromatic, PS)
BCP (16) to (20) were synthesized by the same method as the method for synthesizing the BCP (1) to (5), except that 1-hexanethiol was used instead of 2,2,2-trifluoroethanethiol for the above-described BCP precursors (1) to (5).
Mn and dispersity (PDI=Mw/Mn) of the BCP (16), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (17), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (18), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (19), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (20), measured by size-exclusion chromatography (SEC), were 25,000 g·mol−1 and 1.03.
The analysis result of the NMR measurement of the BCP (17) was as follows.
1H NMR (400 MHZ, CDCl3, δ, ppm): 0.85 to 1.02 (α-CH3, PMMA and PGHMA; —CH2—CH2—CH3, PGHMA), 1.23 to 1.69 (—S—CH2—CH2—CH2—CH2—CH2—, PGHMA; —CH2—CH—, PS backbone), 1.74 to 2.02 (—CH2—CH—, PS backbone; —CH2—C(CH3)—, PGHMA and PMMA), 2.63 (—CH(OH)—CH2—S—CH2—CH2—, PGHMA), 3.60 (—O—CH3, PMMA), 3.99 (—(C═O)O—CH2—CH(OH), PGHMA), 6.39 to 6.85 (o-aromatic, PS), 6.91 to 7.42 (p- and m-aromatic, PS)
BCP (21) to (25) were synthesized by the same method as the method for synthesizing the BCP (1) to (5), except that cyclohexanethiol was used instead of 2,2,2-trifluoroethanethiol for the above-described BCP precursors (1) to (5).
Mn and dispersity (PDI=Mw/Mn) of the BCP (21), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (22), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (23), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (24), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (25), measured by size-exclusion chromatography (SEC), were 25,000 g·mol−1 and 1.03.
The analysis result of the NMR measurement of the BCP (22) was as follows.
1H NMR (400 MHZ, CDCl3, δ, ppm): 0.85 to 1.02 (α-CH3, PMMA and PGCMA), 1.23 to 1.69 (—S—CH(CH2—CH2)—CH2—CH2—CH2—, PGCMA; —CH2—CH—, PS backbone), 1.74 to 2.02 (—S—CH(CH2—CH2)—CH2—CH2—CH2—, PGCMA; —CH2—CH—, PS backbone; —CH2—C(CH3)—, PGCMA and PMMA), 2.63 (—CH(OH)—CH2—S—CH(CH2—CH2)—CH2—CH2—CH2—, PGCMA), 3.60 (—O—CH3, PMMA), 3.99 (—(C═O)O—CH2—CH(OH), PGCMA), 6.39 to 6.85 (o-aromatic, PS), 6.91 to 7.42 (p- and m-aromatic, PS)
The value of x in the obtained BCP (6) to (25) was the same as the proportion of the number of moles of GMA to the total number of moles of MMA and GMA used in the synthesis of the BCP precursor.
The proportion of the volume of the polystyrene block was calculated in the same manner as in Measurement of volume of each block described above.
For each block copolymer synthesized as described above, the number-average molecular weight (Mn), the proportion (% by volume) of the volume of the polystyrene block (PS) to the total volume of the block copolymer, and the value of x in the reaction formula are summarized in Tables 5 to 8. In all of BCP (6) to BCP (25), a density of a structure composed of the constitutional unit induced from methyl methacrylate was 1.18 g·cm−3.
Each component shown in Tables 9 to 12 was mixed and dissolved in the organic solvent component to prepare a resin composition for forming an etching mask pattern (solid content concentration: 1.6% by mass) of each example. Polyethylene glycol monomethyl ether acetate (PGMEA) was used as the organic solvent component.
In Tables 9 to 12, a numerical value in the brackets is a blending amount (part by mass).
Using the resin compositions for forming an etching mask pattern of Examples 5 to 20 and Comparative Examples 2 to 5 described above, Evaluation of resolution and Evaluation of margin of vertical orientation were performed by the same methods as those described in Evaluation 1 above. The results are shown in Table 13. In a case where the resin compositions of Comparative Examples 2 to 5 were used, since the phase-separated structure was not formed, the resolution could not be obtained. These are described as “-”.
Evaluation of vertical orientation was performed by the same method as described in Evaluation 2 above. The results are shown in Table 14.
In Examples 5 to 8, 9 to 12, 13 to 16, and 17 to 20, the Evaluation of resolution was A.
In Examples 5 to 8, 9 to 12, 13 to 16, and 17 to 20, the results of the Evaluation of margin of vertical orientation were excellent as compared with Comparative Examples 2 to 5.
In Examples 5 to 8, 9 to 12, 13 to 16, and 17 to 20, the phase-separated structure having vertical orientation could be favorably formed as compared with Comparative Examples 2 to 5.
BCP (21) to (25) were synthesized by the same method as the method for synthesizing the BCP (1) to (5), except that 3-mercapto-1-hexanol was used instead of 2,2,2-trifluoroethanethiol for the above-described BCP precursors (1) to (5).
Mn and dispersity (PDI=Mw/Mn) of the BCP (26), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (27), measured by size-exclusion chromatography (SEC), were 21,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (28), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (29), measured by size-exclusion chromatography (SEC), were 22,000 g·mol−1 and 1.03.
Mn and dispersity (PDI=Mw/Mn) of the BCP (30), measured by size-exclusion chromatography (SEC), were 25,000 g·mol−1 and 1.03.
The analysis result of the NMR measurement of the BCP (27) was as follows.
1H NMR (400 MHz, CDCl3, δ, ppm):
The value of x in the obtained BCP (26) to (30) was the same as the proportion of the number of moles of GMA to the total number of moles of MMA and GMA used in the synthesis of the BCP precursor.
The proportion of the volume of the polystyrene block was calculated in the same manner as in Measurement of volume of each block described above.
For each block copolymer synthesized as described above, the number-average molecular weight (Mn), the proportion (% by volume) of the volume of the polystyrene block (PS) to the total volume of the block copolymer, and the value of x in the reaction formula are summarized in Table 15. In all of BCP (26) to BCP (30), a density of a structure composed of the constitutional unit induced from methyl methacrylate was 1.18 g·cm−3.
Each component shown in Table 16 was mixed and dissolved in the organic solvent component to prepare a resin composition for forming an etching mask pattern (solid content concentration: 1.6% by mass) of each example. Polyethylene glycol monomethyl ether acetate (PGMEA) was used as the organic solvent component.
In Table 16, a numerical value in the brackets is a blending amount (part by mass).
BCP-26 to 30 each mean the BCP (26) to BCP (30).
Using the resin compositions for forming an etching mask pattern of Examples 21 to 24 and Comparative Example 6 described above, Evaluation of resolution and Evaluation of margin of vertical orientation were performed by the same methods as those described in Evaluation 1 above. The results are shown in Table 17. In a case where the resin compositions of Comparative Example 6 were used, since the phase-separated structure was not formed, the resolution could not be obtained. These are described as “-”.
Evaluation of vertical orientation was performed by the same method as described in Evaluation 2 above. The results are shown in Table 18.
In Examples 21 to 24, the phase-separated structure having vertical orientation could be favorably formed as compared with Comparative Example 6.
While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-073812 | Apr 2023 | JP | national |
| 2023-216947 | Dec 2023 | JP | national |
| 2024-067050 | Apr 2024 | JP | national |
