KR20200040668A - Method for producing pattern and patterned substrate - Google Patents

Abstract

The present invention relates to a pattern forming method having excellent alignment orientation of a phase separating structure by self-organization. The pattern forming method comprises: a step of forming a silicon-containing film; a step of forming a prepattern including a first polymer; a step of forming a lower layer film including a second polymer; a step of coating a composition for forming a self-organizing film containing a third polymer and a solvent; a step of separating a phase; a step of removing at least a partial phase of the self-organizing film; and an etching step. The first polymer is a polymer having a first structure unit. The second polymer is a polymer which includes a molecule chain having the first structure unit and a second structure unit which is different from the first structure unit, and an end structure which is combined with an end of one side of the molecule chain and includes at least one among an amino group, a hydroxyl group, and a carboxyl group. The third polymer is a block copolymer having a block of the first structure unit and a block of the second structure unit.

Description

Pattern formation method and patterned substrate {METHOD FOR PRODUCING PATTERN AND PATTERNED SUBSTRATE}

The present invention relates to a pattern forming method and a patterned substrate.

With the miniaturization of structures of various electronic devices such as semiconductor devices and liquid crystal devices, miniaturization of patterns to be formed is required. Currently, a fine pattern having a line width of about 90 nm can be formed using, for example, an ArF excimer laser, but more fine pattern formation is required.

To this demand, a pattern forming method using a so-called self-organizing phase separation structure that spontaneously forms an ordered pattern has been proposed. As such a pattern forming method, a method of forming an ultrafine pattern by self-organization using a block copolymer formed by copolymerizing monomers having different properties from each other is known (Japanese Patent Publication No. 2008-149447, Japanese Patent Publication) See Publication No. 2002-519728 and Japanese Patent Publication No. 2003-218383). According to this method, by annealing the film containing the block copolymer, polymer structures having the same properties are likely to gather, so that a pattern can be formed in a self-aligning manner. In addition, a method of forming a fine pattern by self-organizing a composition comprising a plurality of polymers having different properties from each other is also known (see US Patent Application Publication 2009/0214823 and Japanese Patent Publication No. 2010-58403).

In such a pattern forming method, it is known that, by forming a film containing a component such as a polymer self-organizing on a lower layer film, micro-phase separation forming the self-organizing structure described above may occur effectively. Various studies have been conducted on this underlayer film, and it is said that various phase separation structures can be formed by appropriately controlling the surface free energy of the underlayer film when self-organizing the block copolymer (Japanese Patent Publication No. 2008-36491). And Japanese Patent Publication No. 2012-174984). However, when these conventional lower layer films are used, when forming a finer pattern, there is a problem that the alignment orientation of the phase separation structure by self-organization becomes insufficient.

Japanese Patent Publication No. 2008-149447 Japanese Patent Publication No. 2002-519728 Japanese Patent Publication No. 2003-218383 US Patent Application Publication 2009/0214823 Specification Japanese Patent Publication No. 2010-58403 Japanese Patent Publication No. 2008-36491 Japanese Patent Publication No. 2012-174984

The present invention has been made on the basis of the above circumstances, and its object is to provide a pattern forming method and a patterned substrate having excellent alignment orientation of a phase separation structure by self-organization.

The invention made to solve the above problems,

Forming a silicon-containing film on a substrate (hereinafter also referred to as a "silicon-containing film forming process");

A step of directly or indirectly forming a prepattern comprising a first polymer (hereinafter also referred to as a "[P] polymer") on the silicon-containing film (hereinafter also referred to as a "prepattern forming step");

A step of forming a lower layer film containing a second polymer (hereinafter, also referred to as "[A] polymer") in the recess of the pre-pattern (hereinafter also referred to as a "lower layer film forming step");

A step of coating a composition for forming a self-organizing film containing a third polymer (hereinafter, also referred to as a "[X] polymer") on the lower layer film and the prepattern (hereinafter also referred to as a "coating step");

A step of phase-separating the coating film formed by the coating process (hereinafter also referred to as a "phase separation process");

A step of removing at least a part of the phase of the self-organizing film formed by the phase separation step (hereinafter also referred to as a "removal step");

A process of etching the substrate using the refinement pattern formed by the removal process (hereinafter also referred to as an "etching process")

As a pattern forming method comprising:

The first polymer is a polymer having a first structural unit,

The second polymer includes a molecular chain having a second structural unit different from the first structural unit and the first structural unit, and at least any one of an amino group, a hydroxyl group, and a carboxy group bonded to one end of the molecular chain It is a polymer having a terminal structure,

It is characterized in that the third polymer is a block copolymer having a block of the first structural unit and a block of the second structural unit.

However, the first structural unit is derived from a first monomer, and the second structural unit is derived from a second monomer having a greater polarity than the first monomer.

Another invention made to solve the above problems is a patterned substrate obtained by the pattern forming method.

Here, "amino group" means a primary amino group (-NH ₂ ), a secondary amino group (-NHR, provided that R is a monovalent organic group) and a tertiary amino group (-NRR ', provided that R and R' are , A monovalent organic group, or a group of these groups combined with each other to represent a part of an aliphatic heterocyclic structure or an aromatic heterocyclic structure composed of nitrogen atoms to which they are attached.). The secondary amino group includes a group containing a nitrogen atom to which one hydrogen atom such as "-CH ₂ -NH-" in a piperidyl group, a morporyl group, or the like is bonded. In addition, a hydrogen atom such as "-CH = N-" in a pyridyl group or a quinolyl group and "-CH ₂ -N (-CH ₂ -)-CH _2- " in an azabicyclooctyl group is bonded to the tertiary amino group. Groups containing nitrogen atoms that are not included are included. However, the cyano group is not a tertiary amino group. "Organic device" refers to a group containing at least one carbon atom.

According to the pattern forming method of the present invention, a patterned substrate having a good pattern can be obtained by forming a phase separation structure by self-organization with excellent alignment orientation and using this excellent phase separation structure. The patterned substrate of the present invention has a good pattern because it is formed using a phase separation structure by self-organization, which is excellent in alignment orientation formed by the pattern forming method. Therefore, these can be suitably used in a lithography process in the manufacture of various electronic devices such as semiconductor devices and liquid crystal devices that require further miniaturization.

1 is a schematic cross-sectional view showing an example of a state after forming a silicon-containing film on one side of a substrate in the pattern forming method of the present invention.
2 is a schematic cross-sectional view showing an example of a state after forming a prepattern on one surface of a silicon-containing film in the pattern forming method of the present invention.
3 is a schematic cross-sectional view showing an example of a state after a lower layer film is formed in a concave portion of a prepattern in the pattern forming method of the present invention.
4 is a schematic cross-sectional view showing an example of a state after forming a coating film of a composition for forming a self-organizing film on one surface of a lower layer film in the pattern forming method of the present invention.
5 is a schematic cross-sectional view showing an example of a state after forming a self-organizing film by phase-separating a coating film in the pattern forming method of the present invention.
6 is a schematic cross-sectional view showing an example of a state after removing a part of the image of a self-organizing film in the pattern forming method of the present invention.

<Pattern formation method>

The pattern forming method includes a silicon-containing film forming step, a pre-pattern forming step, a lower layer film forming step, a coating step, a phase separation step, a removing step, and an etching step. In the pattern forming method, a prepattern is formed using a [P] polymer that is a homopolymer having a structural unit (I) derived from monomer (I), and the underlayer film, structural unit (I) and monomer (I) [A] Polymer in which the terminal structure (I) containing at least one of an amino group, a hydroxy group and a carboxy group is bonded to a molecular chain (I) formed by randomly arranging structural units (II) derived from a monomer (II) having a higher polarity As the [X] polymer of the composition for forming a self-organizing film to be used, wherein the molar ratio of the structural unit (I) / structural unit (II) in the polymer [A] is equal to or greater than the above specified value, the structural unit A block copolymer having a block of I) and a block of structural unit (II) is used.

The pattern forming method includes each of the above steps, and by using the specific polymer as the [P] polymer forming the prepattern, the [A] polymer forming the underlayer film, and the [X] polymer forming the self-organizing film, the magnetic The alignment of the phase-separated structure by organization is excellent. Although the reason for exerting the above-described effect by the above-described pattern forming method having the above-described configuration is not always clear, it can be estimated as follows, for example. That is, the pre-pattern containing the structural unit (I) and the amino group, hydroxy group or carboxy group bound to the silicon-containing film as the terminal structure, and the molar ratio of the structural unit (I) / structural unit (II) to a specific range [ A] Since the phase separation by self-organization occurs better on the surface with the underlayer film containing the polymer, it is considered that the alignment orientation of the phase separation structure is more improved.

Directed Self Assembly refers to the phenomenon of voluntarily constructing an organization or structure, not only due to control from external factors. In the pattern forming method, a film (self-organizing film) having a phase separation structure by self-organizing is formed on a surface of a specific pre-pattern and a lower layer film by applying a composition for forming a self-organizing film, and the self-organizing film is formed. By removing some of the phases, a refinement pattern can be formed.

Hereinafter, each process is demonstrated.

[Process for forming silicon-containing film]

In this step, a silicon-containing film 102 is formed on one surface side of the substrate 101, as shown in FIG. 1.

As the substrate 101, a conventionally known substrate such as a silicon wafer or a wafer coated with aluminum can be used.

(Method of forming silicon-containing film)

The silicon-containing film is formed, for example, by coating a silicon-containing film-forming composition or the like on one side of the substrate. As a composition for forming a silicon-containing film, for example, a composition containing a polysiloxane and a solvent may be mentioned. As a composition for forming a silicon-containing film, various commercially available Spin on Glass materials can be used.

As a coating method of the composition for forming a silicon-containing film, rotation coating, flexible coating, roll coating, etc. are mentioned, for example.

You may heat the coating film formed by coating the composition for forming a silicon-containing film. As the lower limit of the heating temperature, 80 ° C is preferable, 150 ° C is more preferable, and 200 ° C is still more preferable. As an upper limit of the said temperature, 400 degreeC is preferable, 300 degreeC is more preferable, and 250 degreeC is still more preferable. As a lower limit of the time of heating, 5 seconds is preferable, 30 seconds is more preferable, and 50 seconds is still more preferable. As an upper limit of the said time, 1 hour is preferable, 10 minutes are more preferable, and 3 minutes are still more preferable.

As a lower limit of the average thickness of the silicon-containing film to be formed, 10 nm is preferable, 20 nm is more preferable, and 30 nm is more preferable. As an upper limit of the said average thickness, 1,000 nm is preferable, 500 nm is more preferable, and 100 nm is still more preferable.

[Pre-pattern formation process]

In this step, as shown in Fig. 2, a prepattern 103 is formed on the surface of the silicon-containing film 102 on the side opposite to the substrate 101 by using a [P] polymer. Hereinafter, the [P] polymer will be described.

([P] polymer)

[P] The polymer is a homopolymer having a structural unit (I). The polymer [P] may have a structural unit other than the structural unit (I) as long as the effect of the present invention is not impaired. As an upper limit of the content rate of other structural units in the [P] polymer, 5 mol% is preferable, 1 mol% is more preferable, and 0.1 mol% is more preferable with respect to the whole structural unit constituting the [P] polymer. Do. [P] The polymer may have a terminal group (hereinafter also referred to as "terminal group (I)") that is attached to at least one terminal of the main chain. "Main chain" means the longest of the atomic chains in a polymer.

(Structural Unit (I))

The structural unit (I) is a structural unit derived from monomer (I). As a monomer (I), vinyl aromatic compound etc. are mentioned, for example.

As a vinyl aromatic compound, for example

Styrene;

α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, pt-butylstyrene, 2,4,6-trimethylstyrene, p-methoxystyrene, pt-butoxystyrene, 1,2- Divinylbenzene, 1,3-divinylbenzene, 1,4-divinylbenzene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, m-chloromethylstyrene, p-chloromethylstyrene, substituted styrenes such as p-chlorostyrene, p-bromostyrene, p-iodostyrene, p-nitrostyrene, and p-cyanostyrene;

And substituted or unsubstituted vinyl group-containing aromatic hydrocarbons such as vinyl naphthalene, vinyl anthracene, methyl vinyl naphthalene, and vinyl pyrene.

Of these, substituted or unsubstituted styrene is preferable, and unsubstituted styrene is more preferable.

(Terminal (I))

Examples of the terminal group (I) include a monovalent group containing a hetero atom, and the like. [P] When the polymer has a monovalent group containing a hetero atom as the end group (I), the adhesion between the prepattern 103 and the silicon-containing film 102 becomes higher, and as a result, the phase separation structure by self-organization Alignment orientation can be further improved. "Hetero atom" refers to an atom other than a carbon atom and a hydrogen atom. As a hetero atom, oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, silicon atom, tin atom etc. are mentioned, for example.

As the terminal group (I), a monovalent organic group containing a hydroxy group is preferable. When the terminal group (I) contains a hydroxy group, the adhesion between the prepattern 103 and the silicon-containing film 102 can be further enhanced.

As a method of introducing a monovalent group containing a hetero atom as the end group (I) into the [P] polymer, for example, the polymerization end of the main chain obtained by polymerization of the monomer (I) to which the structural unit (I) is imparted, etc. And a method for generating a monovalent group containing a hetero atom as the end group (I) by reacting by adding a terminal stopper containing a hetero atom, followed by treatment with methanol or the like.

As the terminal stopper, for example

As an epoxy compound, 1,2-butylene oxide, butyl glycidyl ether, propylene oxide, ethylene oxide, 2-ethylhexyl glycidyl ether, 4,4'-methylene bis (N, N-diglycylic) Dianiline), etc.,

As a nitrogen-containing compound,

Isocyanate compound, thioisocyanate compound, imidazolidinone, imidazole, aminoketone, pyrrolidone, diethylaminobenzophenone, nitrile compound, aziridine, formamide, epoxyamine, benzylamine, oxime compound, azine, hydrazone , Imine, aminostyrene, vinylpyridine, aminodiphenylethylene, imide compounds, etc.,

As a silane compound, alkoxysilane, aminosilane, ketoiminosilane, isocyanatesilane, siloxane, glycidylsilane, mercaptosilane, vinylsilane, epoxysilane, pyridylsilane, piperazilsilane, pyrrolidonesilane, cyanosilane , Isocyanate silane,

As other compounds, tin halide, silicon halide, carbon dioxide, etc. may be mentioned.

Of these, epoxy compounds are preferred, and 1,2-butylene oxide, butylglycidyl ether, 2-ethylhexylglycidyl ether or propylene oxide is more preferable.

As the lower limit of the number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography (GPC) of the [P] polymer, 1,000 is preferable, 3,000 is more preferable, and 5,000 is more preferable. As an upper limit of the said Mn, 50,000 is preferable, 20,000 is more preferable, and 10,000 is still more preferable.

As the upper limit of the ratio (Mw / Mn) of the weight average molecular weight (Mw) in terms of polystyrene to Mn of the [P] polymer, 5 is preferable, 2 is more preferable, 1.5 is more preferable, and 1.3 is particularly preferable. As the lower limit of the Mw / Mn, 1.05 is preferable, and 1.02 is more preferable.

By setting Mn and Mw / Mn of the [P] polymer in the above range, the alignment orientation of the phase-separated structure by self-organization can be further improved.

Mn and Mw in the present specification, using a GPC column (two "G2000HXL" from Tosoh Corporation, one "G3000HXL" and one "G4000HXL"), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran , Column temperature: a value measured by gel permeation chromatography using monodisperse polystyrene as a standard under analytical conditions of 40 ° C.

(How to form a free pattern)

The prepattern 103 can be formed as follows, for example. That is, first, a composition containing the [P] polymer and a solvent is coated on the surface of the silicon-containing film. You may heat the obtained coating film. As a lower limit of the temperature of heating, 100 ° C is preferable, 150 ° C is more preferable, and 200 ° C is still more preferable. As an upper limit of the said temperature, 350 degreeC is preferable, 300 degreeC is more preferable, and 270 degreeC is still more preferable. As the lower limit of the heating time, 10 seconds is preferable, 1 minute is more preferable, and 2 minutes is more preferable. As an upper limit of the said time, 1 hour is preferable, 10 minutes are more preferable, and 5 minutes are still more preferable. It is preferable to rinse the formed [P] polymer film with a solvent and remove unreacted materials. Subsequently, on the surface opposite to the silicon-containing film 102 of the film of the [P] polymer, a resist composition is coated to form a resist film, and the resist film is exposed and developed to form a resist pattern. Subsequently, by using this resist pattern as a mask and etching the film of the [P] polymer by oxygen / argon plasma etching or the like, a prepattern 103 including the [P] polymer is formed. After etching, in order to more reliably remove the used resist composition, it may be immersed in a thinner solution such as RSD-001.

The shape of the prepattern 103 can be appropriately selected according to the pattern to be finally formed, and can be, for example, a line and space pattern, a hole pattern, a filler pattern, or the like. As a lower limit of the average thickness of the formed prepattern 103, 10 nm is preferable, 20 nm is more preferable, and 30 nm is more preferable. As an upper limit of the said average thickness, 1,000 nm is preferable, 500 nm is more preferable, and 100 nm is still more preferable.

[Process for forming a lower layer film]

In this step, as shown in Fig. 3, a lower layer film 104 containing the polymer [A] is formed in the recess of the prepattern 103. Hereinafter, the polymer [A] will be described.

([A] polymer)

[A] The polymer has at least one of an amino group, a hydroxyl group, and a carboxyl group bonded to at least one terminal of the molecular chain (I) formed by randomly arranging the structural unit (I) and the structural unit (II) and the molecular chain (I). It has a terminal structure (I) containing either. The molecular chain (I) and terminal structure (I) will be described below.

(Molecular chain (I))

In the molecular chain (I), the structural unit (I) and the structural unit (II) are randomly arranged.

(Structural Unit (I))

The structural unit (I) is the same as the structural unit (I) in the above-mentioned [P] polymer. As a monomer (I) which gives a structural unit (I), the compound similar to the monomer (I) used for formation of a [P] polymer, etc. are mentioned, for example.

(Structural unit (II))

The structural unit (II) is a structural unit derived from monomer (II) having a greater polarity than monomer (I).

As a monomer (II), (meth) acrylic acid ester etc. are mentioned, for example.

As (meth) acrylic acid ester, for example

(Meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate;

(Meth) acrylic acid cyclopentyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 1-methylcyclopentyl, (meth) acrylic acid 2-ethyl adamantyl, (meth) acrylic acid 2- (adamantan-1-yl) (Meth) acrylic acid cycloalkyl esters such as propyl;

(Meth) acrylic acid substituted alkyl such as (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 3-hydroxyadamantyl, (meth) acrylic acid 3-glycidylpropyl, (meth) acrylic acid 3-trimethylsilylpropyl Esters and the like.

By using a vinyl aromatic compound as the monomer (I) and (meth) acrylic acid or (meth) acrylic acid ester as the monomer (II), for example, vinyl aromatic compounds such as styrene-methyl methacrylate block copolymer- (meth) The alignment orientation of the phase-separated structure by self-organization using acrylic acid or (meth) acrylic acid ester block copolymer as a forming component of the self-organizing film can be further improved.

As a lower limit of the molar ratio of structural unit (I) / structural unit (II), it is 55/45, 60/40 is preferable, 65/35 is more preferable, and 70/30 is still more preferable. 80/20 is preferable as an upper limit of the said molar ratio, and 75/25 is more preferable.

(Terminal structure (I))

The terminal structure (I) includes at least any one of an amino group, a hydroxyl group, and a carboxy group (-COOH). The terminal structure (I) may be composed of a structural unit containing the group in the polymer [A], or may be a terminal group bonded to one terminal of the main chain of the polymer [A].

Examples of the amino group include primary amino groups, secondary amino groups, tertiary amino groups, and the like.

Examples of the secondary amino group include a monosubstituted amino group such as methylamino group, ethylamino group, cyclohexylamino group, and phenylamino group; -NH-R- (R is a divalent organic group).

Examples of the tertiary amino group include disubstituted amino groups such as dimethylamino group, diethylamino group, dicyclohexylamino group, and diphenylamino group; And trivalent amino groups such as -N = R- (R is a trivalent organic group) and -CH ₂ -N (-CH ₂ -)-CH _2- .

Moreover, as an amino group, the group derived from the amine which has the above-mentioned aliphatic heterocyclic structure or aromatic heterocyclic structure is mentioned.

Among these, from the viewpoint of improving the alignment orientation of the phase-separated structure by self-organization, groups derived from amines having a tertiary amino group or an aliphatic heterocyclic structure or an aromatic heterocyclic structure are preferred, and tertiary amino groups are more preferable, and dialkyl The amino group is more preferred, and the dimethylamino group is particularly preferred.

As a hydroxy group, both an alcoholic hydroxyl group and a phenolic hydroxyl group are included. Of these, alcoholic hydroxy groups are preferred.

The terminal structure (I) is represented by the following formula (1) or the following formula (2), for example (hereinafter, the terminal structure (I) represented by the formula (1) is referred to as "terminal structure (I-1)"). , Terminal structure (I) represented by Formula (2) is also called "terminal structure (I-2)"). The terminal structure (I-1) is a case having a structural unit containing at least one member selected from an amino group, a hydroxy group and a carboxy group, and the terminal structure (I-2) is a word containing an amino group, a hydroxyl group and / or a carboxy group This is the case with short term.

In the formula (1), L is a trivalent group having 1 to 20 carbon atoms. A ¹ is a monovalent group having an amino group, a hydroxy group, or a carboxy group. X is a hydrogen atom, a monovalent organic group having 1 to 20 carbon atoms, -SH or -SA ¹¹ . A ¹¹ is a monovalent group having an amino group, a hydroxy group, or a carboxy group. n represents the number of structural units constituting the block represented by (-L (-A ¹ )-) n, and is an integer of 2 or more. * Represents the site | part binding to the terminal of the said molecular chain (I).

In the formula (2), A ² is a monovalent group having an amino group, a hydroxyl group, or a carboxy group. m is 0 or 1. * Represents the site | part binding to the terminal of the said molecular chain (I).

(Terminal structure (I-1))

The terminal structure (I-1) is represented by the formula (1).

As a lower limit of n which represents the number of structural units represented by (-L (-A ¹ )-) in the terminal structure (I-1), 2 is 3, and 3 is preferable. As an upper limit of said n, 20 is preferable and 10 is more preferable. By setting the value of n to the above range, the alignment orientation of the phase-separated structure by self-organization can be further improved.

The trivalent group having 1 to 20 carbon atoms represented by L constitutes the main chain of the polymer [A], for example, alkanetriyl groups such as ethanetriyl group, and alkanediyl-car such as propanediyl-carbonyloxy group. The group represented by the following partial structure (formula (A ') in formula (A) mentioned later, such as a carbonyloxy group, is mentioned as a preferable thing.

In the formula (A '), R ¹ is a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms. R ² is a single bond, -O- or -COO-. * Represents a binding site.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by X include, for example, (1) a monovalent hydrocarbon group having 1 to 20 carbon atoms, and (2) a carbon number containing a divalent hetero atom-containing group between carbon and carbon of the hydrocarbon group. Groups having 1 to 20 carbon atoms, groups having 1 to 20 carbon atoms in which part or all of the hydrogen atoms of the groups described in (3) and (2) are substituted with a monovalent hetero atom-containing group. have.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include monovalent chain hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, and the like. You can.

The "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. This "hydrocarbon group" is a saturated hydrocarbon group or an unsaturated hydrocarbon group. The "chain hydrocarbon group" does not include a cyclic structure, and refers to a hydrocarbon group composed of only a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. The "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic structure and does not include an aromatic ring structure as the ring structure, and includes both monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic hydrocarbon groups. However, it is not necessary to consist only of an alicyclic structure, and a chain structure may be included in a part of it. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to consist only of an aromatic ring structure, and a chain structure or an alicyclic structure may be included in a part of it.

As a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, for example,

Alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, decyl group, and dodecyl group;

Alkenyl groups such as ethenyl group, propenyl group, and butenyl group;

And alkynyl groups such as ethynyl group, propynyl group, and butynyl group.

As a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, for example,

Monocyclic alicyclic saturated hydrocarbon groups such as cyclopentyl group and cyclohexyl group;

Monocyclic alicyclic unsaturated hydrocarbon groups such as cyclopentenyl group and cyclohexenyl group;

Polycyclic alicyclic saturated hydrocarbon groups such as norbornyl group, adamantyl group, and tricyclodecyl group;

And polycyclic alicyclic unsaturated hydrocarbon groups such as norbornene group and tricyclodecenyl group.

As a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, for example

Aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, and anthryl group;

Aralkyl groups, such as a benzyl group, a phenethyl group, a naphthyl methyl group, and an anthryl methyl group, etc. are mentioned.

Examples of the hetero atom constituting the monovalent and divalent hetero atom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, and a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the divalent hetero atom-containing group include -O-, -CO-, -S-, -CS-, and -NR'-, groups in which two or more of these are combined. R 'is a hydrogen atom or a monovalent hydrocarbon group.

Examples of the monovalent hetero atom-containing group include a halogen atom, a hydroxyl group, a carboxy group, a cyano group, an amino group, and a sulfanyl group.

As the organic group of X, a benzyl group, dodecyl group or t-butyl group is preferable.

As X in the said Formula (1), a hydrogen atom is preferable.

The terminal structure (I-1) is a structural unit represented by (-L (-A ¹ )-) in the formula (1), for example, a third structural unit represented by the following formula (A) (hereinafter, `` Structural unit (III) ''.

In the formula (A), R ¹ is a hydrogen atom, a fluorine atom or a monovalent organic group having 1 to 20 carbon atoms. R ² is a single bond, -O- or -COO-. p is an integer of 1-3. When p is 1, R ³ is a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms. When p is 2 or more, R ³ is a substituted or unsubstituted (1 + p) valent hydrocarbon group having 1 to 20 carbon atoms. A is an amino group, a hydroxy group, or a carboxy group. When p is 2 or more, a plurality of A may be the same or different.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ include, for example, the same groups as the monovalent organic group having 1 to 20 carbon atoms exemplified as X in the formula (1). , Alkyl groups such as methyl group, ethyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group and n-octyl group; Monocyclic alicyclic saturated hydrocarbon groups such as cyclohexyl groups; Fluoroalkyl groups such as trifluoromethyl group and pentafluoroethyl group; And hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group.

R ¹ is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerization of the monomers that give the structural unit (III).

As R ² , a single bond or -COO- is preferable.

As a substituted or unsubstituted (1 + p) valent hydrocarbon group having 1 to 20 carbon atoms represented by R ³ when p is 2 or more, for example, 1 to 20 carbon atoms illustrated as X in the formula (1). A valent hydrocarbon group, a group containing a divalent hetero atom-containing group between the carbon-carbon of the hydrocarbon group, and a part or all of the hydrogen atoms of the group containing the hydrocarbon group and a divalent hetero atom-containing group as a monovalent hetero atom-containing group And groups excluding p hydrogen atoms from the substituted group. Further, when A is an amino group, R ³ and one or a plurality of A may be bonded to each other to form an amine-derived group having an aliphatic heterocyclic structure or an aromatic heterocyclic structure.

As a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms represented by R ³ when p is 1, in the above substituted or unsubstituted (1 + p) valent hydrocarbon group having 1 to 20 carbon atoms, p is One group etc. are mentioned.

Specific examples of -R ^3- (A) _p when A is an amino group include, for example, groups represented by the following formula (a).

In the formula (a), R ³ is a group represented by R ³ in the formula (A), R ⁴ and R ⁵ are, each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a A group containing at least one group selected from -O-, -CO- and -NH- between the carbon-carbons of the hydrocarbon group, or two or more of R ³ , R ⁴ and R ⁵ are combined with each other, and these are bonded. Represents a part of an aliphatic heterocyclic structure of 3 to 20 of reduced water or an aromatic heterocyclic structure of 5 to 20 of reduced water that is composed of nitrogen atoms.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁴ and R ⁵ include groups similar to those of the monovalent hydrocarbon group having 1 to 20 carbon atoms, exemplified as X in the formula (1).

As a group containing at least one group selected from -O-, -CO- and -NH- between carbon-carbon of the hydrocarbon group represented by R ⁴ and R ⁵ , for example, methoxymethyl group, methylcarbonylmethyl group And methyl amino methyl groups.

Examples of the aliphatic heterocyclic structure of reduced water 3 to 20 constituted by two or more of R ³ , R ⁴ and R ⁵ include, for example, azacyclopentane structure, azacyclohexane structure, azanorbornane structure, and the like.

Examples of the aromatic heterocyclic structure of reduced water 5 to 20 composed of two or more of R ³ , R ⁴ and R ⁵ include, for example, a pyrrole structure, a pyridine structure, a quinoline structure, a pyrimidine structure, a pyrazine structure, an imidazole structure, and the like. Can be lifted.

As a specific example of a structural unit (III), it is also called a structural unit (hereinafter, "structural unit (III-1)-(III-21)" represented by following formula (A-1)-(A-21), for example. ) And the like.

In the formulas (A-1) to (A-21), R ¹ has the same meaning as in the formula (A).

Of these, structural units (III-10), (III-16) or (III-19) are preferred.

As a lower limit of the content rate of structural unit (III), 0.1 mol% is preferable, 0.5 mol% is more preferable, 1 mol% is more preferable, and 2 mol% is more preferable with respect to the whole structural unit which comprises [A] polymer. Is particularly preferred. As an upper limit of the said content rate, 30 mol% is preferable, 20 mol% is more preferable, 10 mol% is more preferable, and 7 mol% is especially preferable.

(Terminal structure (I-2))

The terminal structure (I-2) is represented by the formula (2). As A ² in the formula (2), a group represented by -R ^3- (A) _p in the formula (A) is preferable.

As a specific example of terminal structure (I-2), the group etc. which are represented by following formula (2-1)-(2-8) are mentioned, for example.

In the formulas (2-1) to (2-8), * has the same meaning as in the formula (2).

As the lower limit of the Mn of the polymer [A], 1,000 is preferred, 3,000 is more preferred, and 5,000 is even more preferred. As an upper limit of the said Mn, 50,000 is preferable, 20,000 is more preferable, and 10,000 is still more preferable.

As the upper limit of the ratio (Mw / Mn) of the weight average molecular weight (Mw) in terms of polystyrene to Mn of the polymer [A], 5 is preferable, 2 is more preferable, 1.5 is more preferable, and 1.3 is particularly preferable. As the lower limit of the Mw / Mn, 1.05 is preferable, and 1.02 is more preferable.

By setting Mn and Mw / Mn of the polymer [A] in the above range, the alignment orientation of the phase-separated structure by self-organization can be further improved.

(Synthesis method of [A] polymer)

The polymer [A] having the terminal structure (I-1) is a RAFT agent such as a trithiocarbonate compound such as 2-cyano-2-propyldodecyltrithiocarbonate, sec-BuLi, or the like. By using anionic polymerization initiators or radical polymerization initiators such as azobisisobutyronitrile (AIBN), anionic polymerization or control radical polymerization in a suitable solvent, such as monomers (I) of styrene and methyl methacrylate, etc. After polymerizing the monomer (II), a monomer that gives a terminal structure (I-1), such as N, N-dimethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, and methacrylic acid, is further added. It can be synthesized by polymerization.

The polymer [A] having the terminal structure (I-2) is, for example, a RAFT of a trithiocarbonate compound or the like as shown in the synthesis of the polymer [A] having the terminal structure (I-1) described above. After polymerization of a mixture of a monomer, monomer (I) and monomer (II), the trithiocarbonate terminal of the obtained polymer is amine-decomposed using a primary or secondary amine, and at the terminal of the molecular chain (I). After generating the -SH group to be bonded, the -SH group, and an amino group bound to -S- at the terminal end of the molecular chain (I) by clicking reaction with an amine compound, a hydroxy compound or a carboxylic acid having a double or triple bond , Can be synthesized by converting to a monovalent group having a hydroxy group or a carboxy group. In addition, in the presence of a base, an amino group, a hydroxy group, or a carboxy group attached to -S- at the terminal end of the molecular chain (I) by SN2 reaction of a halogenated alkane having an amino group, a hydroxy group or a carboxy group with an amine-decomposed trithiocarbonate terminal. It can also be converted to a monovalent group having.

(Composition for forming a lower layer film)

The underlayer film 104 is also a composition for forming an underlayer film containing, for example, [A] a polymer and a solvent (hereinafter, also referred to as a "[B] solvent") (hereinafter, also referred to as "a composition for forming an underlayer film (I)") Can be formed by filling the concave portion of the prepattern 103. The composition for forming an underlayer film (I) may contain components other than the polymer [A] and the solvent [B] in a range not impairing the effects of the present invention.

([B] solvent)

The solvent [B] is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the polymer [A] and other components contained as necessary.

Examples of the solvent [B] include alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, and hydrocarbon-based solvents. These [B] solvents can use 2 or more types together.

As an alcohol-based solvent, for example

Aliphatic monoalcohol-based solvents having 1 to 18 carbon atoms such as 4-methyl-2-pentanol and n-hexanol;

Alicyclic monoalcohol solvents having 3 to 18 carbon atoms such as cyclohexanol;

Polyhydric alcohol solvents having 2 to 18 carbon atoms such as 1,2-propylene glycol;

And polyhydric alcohol partial ether-based solvents having 3 to 19 carbon atoms, such as propylene glycol monomethyl ether.

As an ether-based solvent, for example

Dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether, and diheptyl ether;

Cyclic ether-based solvents such as tetrahydrofuran and tetrahydropyran;

And aromatic ring-containing ether solvents such as diphenyl ether and anisole.

As a ketone solvent, for example

Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, Chain ketone-based solvents such as di-iso-butyl ketone and trimethylnonanone;

Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and methylcyclohexanone;

And 2,4-pentanedione, acetonyl acetone, and acetophenone.

As an amide solvent, for example

Cyclic amide solvents such as N, N'-dimethylimidazolidinone and N-methylpyrrolidone;

Chain amides such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide and N-methylpropionamide And solvents.

As an ester solvent, for example

Acetic acid ester solvents such as n-butyl acetate;

Monocarboxylic acid ester solvents such as lactic acid ester solvents such as ethyl lactate and butyl lactate;

Polyhydric alcohol carboxylate-based solvents such as propylene glycol acetate;

Polyhydric alcohol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate;

Polycarboxylic acid diester-based solvents such as diethyl oxalate;

And carbonate-based solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate.

As a hydrocarbon-based solvent, for example

aliphatic hydrocarbon solvents having 5 to 12 carbon atoms such as n-pentane and n-hexane;

And aromatic hydrocarbon-based solvents having 6 to 16 carbon atoms such as toluene and xylene.

Of these, ester-based solvents are preferable, polyhydric alcohol partial ether carboxylate-based solvents and / or lactic acid ester-based solvents are more preferable, and propylene glycol monomethyl ether acetate and / or ethyl lactate is more preferable. [B] By using the solvent as a solvent, the alignment orientation of the phase-separated structure by self-organization can be further improved.

(Other ingredients)

As another component, surfactant, a crosslinking agent, etc. are mentioned, for example. The surfactant is a component capable of improving the coatability of the composition for forming an underlayer film (I). When the composition for forming an underlayer film (I) contains a crosslinking agent, a crosslinking reaction between the crosslinking agent and the polymer [A] occurs, and heat resistance of the formed underlayer film can be improved.

(Method for producing a composition for forming a lower layer film)

The composition for forming the underlayer film (I) is, for example, [A] polymer, [B] solvent and other components, if necessary, mixed in a predetermined ratio, preferably the obtained mixture is, for example, pores of about 0.45 µm It can be manufactured by filtration with a filter or the like. As a lower limit of the solid content concentration of the composition for forming an underlayer film (I), 0.1 mass% is preferable, 0.5 mass% is more preferable, 0.8 mass% is more preferable, and 1 mass% is particularly preferable. As an upper limit of the said solid content concentration, 50 mass% is preferable, 30 mass% is more preferable, 10 mass% is more preferable, and 5 mass% is especially preferable.

(How to form the lower layer film)

The lower layer film 104 is formed by coating the composition (I) for forming the lower layer film by a known method such as a spin coating method, and curing the coating film formed on the concave portion of the prepattern 103 by heating and / or exposing it. May be Examples of radiation used for this exposure include visible light, ultraviolet light, far ultraviolet light, X-rays, electron beams, γ-rays, molecular beams, and ion beams. As the lower limit of the temperature of the heating, 100 ° C is preferable, 120 ° C is more preferable, 150 ° C is more preferable, and 180 ° C is particularly preferable. As an upper limit of the said temperature, 400 degreeC is preferable, 300 degreeC is more preferable, 240 degreeC is more preferable, and 220 degreeC is especially preferable. As the lower limit of the heating time, 10 seconds is preferable, 30 seconds is more preferable, and 1 minute is more preferable. As an upper limit of the said heating time, 30 minutes are preferable, 10 minutes are more preferable, and 5 minutes are still more preferable. The atmosphere for heating the coating film may be an air atmosphere or an inert gas atmosphere such as nitrogen gas.

The lower limit of the average thickness of the lower layer film 104 is preferably 10 nm, more preferably 20 nm, and even more preferably 30 nm. As an upper limit of the said average thickness, 1,000 nm is preferable, 500 nm is more preferable, and 100 nm is still more preferable.

It is preferable that the surface of the lower layer film 104 and the surface of the prepattern 103 form substantially the same plane. That is, the average thickness of the lower layer film 104 is preferably approximately the same as the average thickness of the prepattern 103. By doing in this way, the alignment orientation of the phase-separated structure by self-organization can be further improved. The self-organizing film is laminated on the surfaces of the lower layer film 104 and the prepattern 103.

[Coating process]

In this step, a composition for forming a self-assembled film containing a polymer [X] on a surface opposite to the silicon-containing film 102 of the lower layer film 104 (hereinafter, referred to as “a composition for forming a self-assembled film (I ) ”.

(Composition for forming self-organizing film)

The composition (I) for forming a self-organizing film contains a [X] polymer. The composition for forming a self-organizing film usually contains a solvent (hereinafter, also referred to as "[S] solvent"), and to the extent that the effects of the present invention are not impaired, other than [X] polymer and [S] solvent It may contain an ingredient.

([X] polymer)

[X] The polymer is a block copolymer having a block of structural units (I) and a block of structural units (II).

The structural unit (I) and the structural unit (II) are the same as the structural unit (I) and the structural unit (II) of the molecular chain (I) of the polymer [A] described above. That is, the [X] polymer is a block copolymer having a block formed of the monomer (I) and a block formed of the monomer (II).

As the [X] polymer, a block copolymer having a block formed of a vinyl aromatic compound and a block formed of (meth) acrylic acid or (meth) acrylic acid ester is preferable, and a styrene-methyl methacrylate block copolymer is more preferable. Do.

As the lower limit of the Mn of the [X] polymer, 1,000 is preferable, 5,000 is more preferable, and 10,000 is more preferable. As an upper limit of the said Mn, 300,000 are preferable, 200,000 are more preferable, and 100,000 are still more preferable.

As an upper limit of Mw / Mn of [X] polymer, 5 is preferable, 2 is more preferable, 1.5 is more preferable, 1.3 is especially preferable, and 1.1 is more particularly preferable. The lower limit of the Mw / Mn is usually 1, preferably 1.05, and more preferably 1.02.

By setting Mn and Mw / Mn of the [X] polymer in the above range, the alignment orientation of the phase-separated structure by self-organization can be further improved.

([S] solvent)

The [S] solvent is not particularly limited as long as it can dissolve or disperse the [X] polymer and other components contained as necessary. Examples of the solvent [S] include the same solvents as those exemplified as the solvent [B] of the composition (I) for forming the underlayer film described above.

(Other ingredients)

As another component, surfactant etc. are mentioned, for example.

(How to form a coating film)

A spin coating method etc. are mentioned as a coating method of the composition (I) for self-organizing film formation. As shown in FIG. 4, the composition (I) for forming a self-organizing film is coated on the surfaces of the prepattern 103 and the lower layer film 104, thereby forming a coating film 105.

[Phase separation process]

In this step, the coating film 105 formed by the coating step is phase separated. As a result, as shown in Fig. 5, a self-organizing film 106 is formed.

In the phase separation of the coating film 105, by performing annealing or the like, sites having the same properties are accumulated to form an ordered pattern spontaneously, so-called self-organization can be promoted.

As an annealing method, heating by an oven, a hot plate, etc. is mentioned, for example. As the lower limit of the temperature of this heating, 80 ° C is preferable, 150 ° C is more preferable, and 200 ° C is still more preferable. As an upper limit of the said temperature, 400 degreeC is preferable, 350 degreeC is more preferable, and 300 degreeC is still more preferable. As the lower limit of the heating time, 10 seconds is preferable, 1 minute is more preferable, and 3 minutes is more preferable. As an upper limit of the said time, 120 minutes are preferable, 60 minutes are more preferable, and 10 minutes are still more preferable. Annealing may be performed in air or under an inert gas atmosphere such as nitrogen. When annealing is performed in an inert gas atmosphere, the pattern size is easy to stabilize, and phase separation defects can be reduced.

As a lower limit of the average thickness of the self-organizing film 106 to be formed, 1 nm is preferable, 5 nm is more preferable, and 10 nm is still more preferable. As an upper limit of the said average thickness, 500 nm is preferable, 100 nm is more preferable, and 50 nm is still more preferable.

As shown in FIG. 5, a phase separation structure is formed on the surfaces of the lower layer film 104 and the prepattern 103. When the pre-pattern 103 is a line-and-space pattern, usually, the image 106a of the block of the structural unit (I) having high affinity with the pre-pattern 103 is formed on the surface of the pre-pattern 103 , On the surface of the lower layer film 104, a lamellar phase separation structure in which the phase 106a of the block of the structural unit (I) and the phase 106b of the block of the structural unit (II) are alternately arranged are formed. When the pre-pattern 103 is a hole-shaped pattern, usually, an image of a block of the structural unit (I) having high affinity with the pre-pattern 103 is formed on the surface of the pre-pattern 103 and the lower layer film 104 On the surface of), a phase separation structure of concentric circles is formed in which the phase of the block of the structural unit (I) and the phase of the block of the structural unit (II) are alternately arranged.

[Remove process]

In this step, at least a part of the phase of the self-organizing film formed by the phase separation step is removed. Thereby, a refinement pattern is formed.

One phase of 106a and 106b can be removed by etching using the difference in etching rate of each phase separated by self-organization. 6 shows a state after removing some of the phases 106b of the phase separation structure.

As a method of removing one of the phases 106a and 106b of the phase separation structure of the self-organizing film 106, for example, reactive ion etching (RIE) such as chemical dry etching and chemical wet etching; And known methods such as sputter etching and physical etching such as ion beam etching. Among these, reactive ion etching (RIE) is preferred, chemical dry etching using CF ₄ , O ₂ gas, etc., organic solvents such as methyl isobutyl ketone (MIBK), 2-propanol (IPA), and etching of liquids such as hydrofluoric acid Chemical dry etching (wet development) using a solution is more preferable.

[Etching process]

In this step, the substrate 101 is etched using the refinement pattern formed by the removal step. Thereby, a patterned substrate is obtained.

The substrate is patterned by etching once or multiple times by performing a single etching or a plurality of sequential etchings using the micronization pattern including a part of the image 106a of a part of the self-organizing film remaining in the removal process shown in FIG. 6 as a mask. Can be angry. After the patterning of the substrate is completed, the image or the like used as a mask is removed from the substrate by dissolution treatment or the like, and finally a substrate pattern (patterned substrate) can be obtained. As this obtained pattern, a line and space pattern, a hole pattern, etc. are mentioned, for example. As the etching method, a method similar to the etching method illustrated in the removal step can be used. Among these, dry etching is preferred. The gas used for dry etching can be appropriately selected according to the material of the substrate. For example, when the substrate is a silicon material, a mixed gas of freon-based gas and SF ₄ may be used. In addition, when the substrate is a metal film, a mixed gas of BCl ₃ and Cl ₂ or the like can be used.

The patterned substrate obtained by the pattern forming method is suitably used for semiconductor devices and the like, and the semiconductor devices are widely used for LEDs, solar cells, and the like.

[Example]

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. In addition, unless otherwise specified, commercially available reagents were used for each compound described in the following examples. The measurement method of various physical property values is shown below.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]

Using a GPC column (two "G2000HXL" from Tosoh Corporation, one "G3000HXL" and one "G4000HXL"), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40 ° C under analysis conditions , It was measured by gel permeation chromatography (GPC) based on monodisperse polystyrene.

[ ¹³ C-NMR analysis]

¹³ C-NMR analysis was performed using "JNM-EX400" from Nippon Denshi, using DMSO-d ₆ as a measurement solvent. The content ratio of each structural unit was calculated from the peak area ratio corresponding to each structural unit in the spectrum obtained by ¹³ C-NMR analysis.

<Synthesis of [A] polymer>

[Synthesis Example 1]

In a 200 mL 3-neck flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of azobisisobutyronitrile (AIBN), 17.5 g of styrene, 6.00 g of methyl methacrylate, and 40 g of anisole Then, the mixture was heated and stirred at 80 ° C for 5 hours under nitrogen. Subsequently, 2.01 mL of N, N-dimethylaminoethyl methacrylate was added to a syringe, 0.098 g of AIBN was further added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to purify and precipitate, and the obtained precipitate was dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA), AIBN 0.49 g, tert-dodecanethiol 2.03 g, and propylene glycol monomethyl ether (PGME) ) 1 g was added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen.

The resulting reaction solution was concentrated, diluted with 10 g of tetrahydrofuran (THF), and then added to 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.6 g of a polymer represented by the following formula (A-1). Mn of the polymer (A-1) was 6,060, Mw was 7,300, and Mw / Mn was 1.20. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-1) was as described in the following formula (A-1), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 73.7: 26.3.

[Synthesis Example 2]

To a 200 mL three-neck flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 17.5 g of styrene, 6.00 g of methyl methacrylate, and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 1.02 mL of methacrylic acid was added to a syringe, 0.098 g of AIBN was further added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, the obtained precipitate was dissolved in 20 g of PGMEA, 0.49 g of AIBN, 2.03 g of tert-dodecanethiol and 1 g of PGME were added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen. Did.

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then introduced into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.4 g of a polymer represented by the following formula (A-2). Mn of polymer (A-2) was 7,100, Mw was 8,400, and Mw / Mn was 1.19. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-2) was as described in the following formula (A-2), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 73.7: 26.3.

[Synthesis Example 3]

To a 200 mL three-necked flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 16.3 g of styrene, 7.22 g of methyl methacrylate and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 1.46 mL of 2-hydroxyethyl methacrylate was added to a syringe, 0.098 g of AIBN was further added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, the obtained precipitate was dissolved in 20 g of PGMEA, 0.49 g of AIBN, 2.03 g of tert-dodecanethiol and 1 g of PGME were added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen. Did.

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.9 g of a polymer represented by the following formula (A-3). Mn of the polymer (A-3) was 7,700, Mw was 9,300, and Mw / Mn was 1.21. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-3) was as described in the following formula (A-3), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 68.4: 31.6.

[Synthesis Example 4]

To a 200 mL 3-neck flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 16.3 g of styrene, 7.21 g of methyl methacrylate, and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 2.01 mL of N, N-dimethylaminoethyl methacrylate was added to a syringe, 0.098 g of AIBN was further added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, the obtained precipitate was dissolved in 20 g of PGMEA, 0.49 g of AIBN, 2.03 g of tert-dodecanethiol and 1 g of PGME were added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen. Did.

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.1 g of a polymer represented by the following formula (A-4). Mn of the polymer (A-4) was 6,500, Mw was 7,800, and Mw / Mn was 1.20. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-4) was as described in the following formula (A-4), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 68.4: 31.6.

[Synthesis Example 5]

To a 200 mL three-neck flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 13.8 g of styrene, 9.60 g of methyl methacrylate, and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 2.01 mL of N, N-dimethylaminoethyl methacrylate was added to a syringe, 0.098 g of AIBN was further added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, the obtained precipitate was dissolved in 20 g of PGMEA, 0.49 g of AIBN, 2.03 g of tert-dodecanethiol and 1 g of PGME were added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen. Did.

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.1 g of a polymer represented by the following formula (A-5). Mn of the polymer (A-5) was 6,500, Mw was 8.300, and Mw / Mn was 1.27. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-5) was as described in the following formula (A-5), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 57.9: 42.1.

[Synthesis Example 6]

To a 200 mL three-necked flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 7.50 g of styrene, 15.6 g of methyl methacrylate, and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 2.01 mL of N, N-dimethylaminoethyl methacrylate was added to a syringe, 0.098 g of AIBN was further added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, the obtained precipitate was dissolved in 20 g of PGMEA, 0.49 g of AIBN, 2.03 g of tert-dodecanethiol and 1 g of PGME were added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen. Did.

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.2 g of a polymer represented by the following formula (A-6). Mn of the polymer (A-6) was 6,800, Mw was 8,300, and Mw / Mn was 1.22. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-6) was as described in the following formula (A-6), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 31.6: 68.4.

[Synthesis Example 7]

To a 200 mL three-necked flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 7.50 g of styrene, 15.6 g of methyl methacrylate, and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 1.46 mL of 2-hydroxyethyl methacrylate was added to a syringe, 0.098 g of AIBN was further added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, the obtained precipitate was dissolved in 20 g of PGMEA, 0.49 g of AIBN, 2.03 g of tert-dodecanethiol and 1 g of PGME were added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen. Did.

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.1 g of a polymer represented by the following formula (A-7). Mn of the polymer (A-7) was 6,800, Mw was 8,300, and Mw / Mn was 1.22. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-7) was as described in the following formula (A-7), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 31.6: 68.4.

[Synthesis Example 8]

To a 200 mL three-necked flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 7.50 g of styrene, 15.6 g of methyl methacrylate, and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 0.098 g (0.6 mmol) of AIBN was added, followed by stirring under nitrogen at 80 ° C. for 3 hours.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, the obtained precipitate was dissolved in 20 g of PGMEA, 0.49 g of AIBN, 2.03 g of tert-dodecanethiol and 1 g of PGME were added, and the mixture was heated and stirred at 90 ° C. for 2 hours under nitrogen. Did.

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.0 g of a polymer represented by the following formula (A-8). Mn of the polymer (A-8) was 6,500, Mw was 8,000, and Mw / Mn was 1.23. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-8) was as described in the following formula (A-8), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 32:68.

[Synthesis Example 9]

To a 200 mL three-necked flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 17.5 g of styrene, 7.22 g of methyl methacrylate and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 0.098 g of AIBN was added, and the mixture was heated and stirred at 80 ° C. for 3 hours under nitrogen.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, and the obtained precipitate was dissolved in 20 g of PGMEA, 1.47 g of n-butylamine and 2 g of propylene glycol monomethyl ether were added, and the mixture was heated and stirred at 50 ° C. for 3 hours under nitrogen. .

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.7 g of a polymer (a-9) having a -SH group at the terminal.

To 3.00 g of this polymer (a-9), 0.69 g of N, N-dimethylallylamine, 10 g of propylene glycol monomethyl ether acetate and 0.164 g of AIBN were added, and the mixture was heated and stirred at 60 ° C. for 5 hours under nitrogen. The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained white solid was dried under reduced pressure to obtain a polymer represented by the following formula (A-9). Mn of the polymer (A-9) was 7,600, Mw was 9,200, and Mw / Mn was 1.21. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-9) was as described in the following formula (A-9), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 70:30.

[Synthesis Example 10]

To a 200 mL three-necked flask, 0.69 g of 2-cyano-2-propyldodecyltrithiocarbonate, 0.098 g of AIBN, 17.5 g of styrene, 7.22 g of methyl methacrylate and 40 g of anisole were added, and at 80 ° C. under nitrogen. The mixture was stirred for 5 hours. Subsequently, 0.098 g of AIBN was added, and the mixture was heated and stirred at 80 ° C. under nitrogen for 3 hours.

The obtained polymerization reaction solution was added to 500 g of methanol to precipitate and purify, and the obtained precipitate was dissolved in 20 g of PGMEA, 1.47 g of n-butylamine and 2 g of propylene glycol monomethyl ether were added, and the mixture was heated and stirred at 50 ° C. for 3 hours under nitrogen. .

The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained pale yellow solid was dried under reduced pressure to obtain 18.3 g of a polymer (a-10) having a -SH group at the terminal.

To 3.00 g of this polymer (a-10), 0.58 g of 3-butene-1-ol, 10 g of propylene glycol monomethyl ether acetate and 0.164 g of AIBN were added, and the mixture was heated and stirred at 60 ° C. for 5 hours under nitrogen. The obtained reaction solution was concentrated, diluted with 10 g of THF, and then poured into 500 g of methanol to precipitate and purify. The obtained white solid was dried under reduced pressure to obtain a polymer represented by the following formula (A-10). Mn of the polymer (A-10) was 7,500, Mw was 9,150, and Mw / Mn was 1.20. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit in the polymer (A-10) was as described in the following formula (A-10), and the styrene-derived unit (first structural unit) and methacryl The molar ratio of the unit derived from methyl acid (second structural unit) was 70:30.

<Synthesis of [P] polymer>

[Synthesis Example 11] (Synthesis of polystyrene brush)

After drying the flask reaction vessel of 500 mL under reduced pressure, 120 g of THF subjected to distillation and dehydration treatment was introduced under a nitrogen atmosphere, and cooled to -78 ° C using a dry ice-acetone bath. Thereafter, 3.10 mL of a 1N cyclohexane solution of sec-butyllithium (sec-BuLi) was injected into THF, and then 16.6 mL of styrene subjected to adsorption filtration fractionation and distillation dehydration treatment with silica gel for removing the polymerization inhibitor. It was added dropwise over 30 minutes, and it was confirmed that the polymerization system was orange. At the time of this dropwise injection, care was taken so that the internal temperature of the reaction solution did not exceed -60 ° C. After completion of dropping, the mixture was aged for 30 minutes. Thereafter, 0.63 mL of 2-ethylhexylglycidyl ether and 1 mL of methanol as terminal terminators were injected to terminate the polymerization reaction. The reaction solution was heated to room temperature, and the obtained reaction solution was concentrated to be substituted with methyl isobutyl ketone (MIBK). Thereafter, 1,000 g of a 2% by mass aqueous oxalic acid aqueous solution was injected and stirred, and after standing, the lower aqueous layer was removed. This operation was repeated 3 times to remove the Li salt. Thereafter, 1,000 g of ultrapure water was injected and stirred, and the lower water layer was removed. After repeating this operation three times to remove oxalic acid, the resulting solution was concentrated and dropped into 500 g of methanol to precipitate a polymer, and the solid was recovered with a Buchner funnel. The polymer was dried under reduced pressure at 60 ° C. to obtain 14.8 g of a polymer (P-1) which is a polystyrene having an alcoholic hydroxyl group derived from white 2-ethylhexylglycidyl ether at the end.

As for this polymer (P-1), Mw was 6,100, Mn was 5,700, and Mw / Mn was 1.07.

<Synthesis of [X] polymer>

[Synthesis Example 12] (Synthesis of block copolymer)

After drying the flask reaction vessel of 500 mL under reduced pressure, 200 g of THF subjected to distillation and dehydration treatment was introduced under a nitrogen atmosphere, and cooled to -78 ° C using a dry ice-acetone bath. Subsequently, 0.40 mL of a 1N cyclohexane solution of sec-butyllithium (sec-BuLi) was injected into THF, and then 22.1 mL of styrene subjected to adsorption filtration fractionation with silica gel and distilled dehydration to remove the polymerization inhibitor. To the reaction solution, it was added dropwise over 30 minutes, being careful not to exceed -60 ° C. After stirring for 30 minutes, 0.15 mL of 1,1-diphenylethylene and 1.42 mL of 0.5N-THF solution of lithium chloride were added. In addition, 18.0 mL of methyl methacrylate, which was subjected to adsorption filtration fractionation by silica gel and distilled dehydration to remove the polymerization inhibitor, was added dropwise into the solution over 30 minutes, and then reacted for 120 minutes. Thereafter, 1 mL of methanol as a terminal terminator was injected to terminate the polymerization reaction. The reaction solution was heated to room temperature, and the obtained reaction solution was concentrated and replaced with MIBK. Thereafter, 1,000 g of an aqueous 2 mass% oxalic acid solution was injected and stirred, and after standing, the Li salt was removed by an operation of removing the lower water layer. Thereafter, 1,000 g of ultrapure water was injected and stirred, oxalic acid was removed by an operation of removing the lower water layer, and the resulting solution was concentrated and dropped into 500 g of methanol to precipitate a polymer, and the solid was recovered with a Buchner funnel. Then, it was washed with cyclohexane, and the solid was recovered again with a Buchner funnel. The solid was dried under reduced pressure at 60 ° C to obtain 37.4 g of a white block copolymer (X-1).

As for this block copolymer (X-1), Mw was 58,600, Mn was 57,000, and Mw / Mn was 1.03. In addition, as a result of ¹ H-NMR analysis, the block copolymer (X-1) had a content ratio of repeating units (PS) derived from styrene and repeating units (PMMA) derived from methyl methacrylate, respectively, 50.0 mass. % (50.0 mol%) and 50.0 mass% (50.0 mol%). Further, the block copolymer (X-1) is a diblock copolymer.

<Preparation of a composition for forming a lower layer film>

The [S] solvent used in the production of the composition for forming a lower layer film is shown below.

[[S] solvent]

S-1: Propylene glycol monomethyl ether acetate

S-2: ethyl lactate

[Production Example 1]

[A] To 1.2 g of (A-1) as a polymer, 98.8 g of (S-1) as a [S] solvent was added and stirred, followed by filtration through a high-density polyethylene filter having a pore size of 0.45 µm to form a lower layer film. Composition (S-1) was prepared.

[Production Examples 2 to 12]

Compositions (S-2) to (S-12) for underlayer film formation were prepared in the same manner as in Production Example 1, except that each component of the type and compounding amount shown in Table 1 below was used.

<Formation of pattern>

[Examples 1 to 9 and Comparative Examples 1 to 3]

(Formation of silicon-containing film and pre-pattern)

Using Tokyo Electron's "Clean Track-12", Spin on Glass material (JSR's "NFC ISX568") was coated to a thickness of 40 nm on a 300 mm wafer, and baked at 220 ° C for 90 seconds under nitrogen. . Subsequently, on the formed SiARC, the synthesized polystyrene brush (polymer (P-1)) was coated with a thickness of 30 nm, baked at 250 ° C. for 3 minutes, and after brush formation, rinsed with PGMEA, and unreacted material. Was removed. Subsequently, an ArF immersion resist ("AEX1191JN" from JSR) was coated to a thickness of 50 nm, and prebaked at 100 DEG C for 1 minute, followed by an exposure machine (ASML's "XT1950i scanner" (NA; 1.35, dipole (dipole) roughness σou) / σin 0.76 / 0.66)), and post exposure bake (post exposure bake) at 100 ° C for 1 minute. The development was conducted for 30 seconds with butyl acetate, thereby producing an LS pattern with a 90 nm pitch.

For this wafer, in order to remove the resist pattern, oxygen / argon plasma etching (apparatus; "NZ-1300" by Dr. Al; power supply; MW (microwave power), vacuum degree; 50mtorr, 15sec / O ₂ , 100secm / Ar , power (power): 50 W), and a trench was prepared by etching.

Further, the resist pattern was etched by "A RIE-1701 reactive Ion Etch Plasma" manufactured by Nordson MARCH. Thereafter, in order to completely remove the resist material, a wafer having a pre-pattern was produced by immersing in RSD-001 at room temperature for 15 minutes, then rinsing with PGMEA, and then blowing with air (air).

(Formation of lower layer film)

On the wafer on which the prepared prepattern was formed, the composition for forming the underlayer film formed above was coated to a thickness of 30 nm, and heat treated at 200 ° C. for 3 minutes, followed by PGMEA rinsing and air blowing to form a lower layer film in the trench. Formed.

(Formation of self-organizing film)

A composition for forming a self-assembled film (PS-block-PMMA 30nm P_LS) in which 1.3 g of the synthesized block copolymer (polymer (X-1)) was dissolved in 98.7 g of propylene glycol monomethyl ether acetate was coated with a thickness of 35 nm. , Self-organizing film was formed by heat annealing at 250 ° C. for 5 minutes under nitrogen and phase-separating the coating film.

<Evaluation>

The shape of the alignment orientation was observed using "CG-6300" from Hitachi High-Technology, and the pitch size (L0) was measured. About the pitch analysis, analysis was performed based on the "Freq analyzer DSA" produced by IMEC based on MATLAB2017b. Alignment orientation was evaluated as "○" (good) for alignment alignment and "x" (bad) for not being able to confirm the finger print pattern and pattern. In addition, the measured value of L0 (nm) is shown together in Table 2 below.

As can be seen from the results in Table 2, according to the pattern forming method of the examples, the alignment orientation of the phase-separated structure by self-organization can be made good. On the other hand, as a pattern forming method of the comparative example, it was not possible to form a finger print pattern and a pattern.

According to the pattern forming method of the present invention, a phase-separated structure by self-organization with excellent alignment orientation can be formed, and a substrate having a good pattern can be obtained using this phase-separated structure. The patterned substrate of the present invention has a good pattern by using a phase separation structure by self-organization which is excellent in alignment orientation formed by the pattern forming method. Therefore, these can be suitably used in a lithography process in the manufacture of various electronic devices such as semiconductor devices and liquid crystal devices that require further miniaturization.

101: substrate
102: silicon-containing film
103: free pattern
104: lower layer film
105: coating film
106: self-organizing film
106a: One phase constituting the self-organizing film
106b: the other image constituting the self-organizing film

Claims (11)

Forming a silicon-containing film on the substrate;
Forming a prepattern comprising a first polymer directly or indirectly on the silicon-containing film;
Forming a lower layer film containing a second polymer in a concave portion of the prepattern;
A step of coating a composition for forming a self-organizing film containing a third polymer on the lower layer film and the pre-pattern,
A step of phase-separating the coating film formed by the coating process,
Removing a phase of at least a portion of the self-organizing film formed by the phase separation process to form a pattern;
Process of etching the substrate using the pattern formed by the removal process
As a pattern forming method comprising:
The first polymer is a polymer having a first structural unit,
The second polymer includes a molecular chain having a second structural unit different from the first structural unit and the first structural unit, and at least any one of an amino group, a hydroxyl group, and a carboxy group bonded to one end of the molecular chain It is a polymer having a terminal structure,
The pattern formation method characterized in that the third polymer is a block copolymer having a block of the first structural unit and a block of the second structural unit.
However, the first structural unit is derived from a first monomer, and the second structural unit is derived from a second monomer having a greater polarity than the first monomer. The pattern formation method according to claim 1, wherein the terminal structure in the second polymer is represented by the following formula (1) or the following formula (2).

(In formula (1), L is a trivalent group having 1 to 20 carbon atoms. A ¹ is a monovalent group having an amino group, a hydroxyl group or a carboxy group. X is a hydrogen atom, a monovalent organic group having 1 to 20 carbon atoms,- SH or -SA ^11. A ¹¹ is a monovalent group having an amino group, a hydroxy group or a carboxy group, _n represents the number of structural units constituting the block represented by (-L (-A ¹ )-) _n , 2 It is an integer of the above.
In Formula (2), A ² is a monovalent group having an amino group, a hydroxyl group, or a carboxy group. m is 0 or 1. * Indicates a site that binds to the end of the molecular chain.) The method for forming a pattern according to claim 2, wherein the terminal structure represented by the formula (1) is represented by the following formula (1-A).

(In formula (A), R ¹ is a hydrogen atom, a fluorine atom or a monovalent organic group having 1 to 20 carbon atoms. R ² is a single bond, -O- or -COO-. P is an integer from 1 to 3) When p is 1, R ³ is a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms. When p is 2 or more, R ³ is a substituted or unsubstituted carbon atom having 1 to 20 carbon atoms (1 + p) is a valent hydrocarbon group, A is an amino group, a hydroxy group, or a carboxy group, when p is 2 or more, a plurality of A's may be the same or different.) The pattern formation method according to claim 3, wherein the content ratio of the third structural unit in the second polymer is 0.1 mol% or more and 30 mol% or less. The pattern formation method according to any one of claims 1 to 4, wherein the first monomer is a vinyl aromatic compound. The pattern formation method according to any one of claims 1 to 5, wherein the second monomer is a (meth) acrylic acid ester. The pattern formation method according to any one of claims 1 to 6, wherein the terminal structure in the second polymer contains an amino group, and the amino group is a tertiary amino group. The pattern formation method according to any one of claims 1 to 7, wherein the molar ratio of the first structural unit to the second structural unit in the second polymer is 60/40 or more and 80/20 or less. The pattern forming method according to any one of claims 1 to 8, wherein the composition used for forming the lower layer film contains a solvent, and the solvent contains a lactic acid ester. The pattern forming method according to any one of claims 1 to 9, wherein a line and space pattern or a hole pattern is formed as the pattern. A patterned substrate obtained by the pattern forming method according to any one of claims 1 to 10.

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