KR102238922B1 - Composition for forming underlayer and directed self assembly lithography process - Google Patents

Abstract

(화학식 (1) 중, A는 (m+n)가의 연결기이다. D는 탄소수 10 이상의 1가의 유기기이다. E는 Si-OH 또는 Si-H와 반응할 수 있는 기이다. m 및 n은 각각 독립적으로 1 내지 200의 정수이다.)An object of the present invention is to provide a composition for forming a base film capable of forming a phase-separated structure by self-organization and forming a rectangular pattern.
The present invention is a composition for forming a base film disposed between a layer containing a silicon atom and a self-organizing film in a self-organizing lithography method, and a compound having a group capable of reacting with Si-OH or Si-H, and a solvent It is a composition for forming a base film containing, and a retreat contact angle of the base film with pure water is 70° or more and 90° or less. It is preferable that the compound is represented by the following general formula (1).

(In formula (1), A is a (m+n) valent linking group. D is a monovalent organic group having 10 or more carbon atoms. E is a group capable of reacting with Si-OH or Si-H. m and n are Each independently an integer of 1 to 200.)

Description

A composition for forming an underlying film and a self-organizing lithography method {COMPOSITION FOR FORMING UNDERLAYER AND DIRECTED SELF ASSEMBLY LITHOGRAPHY PROCESS}

The present invention relates to a composition for forming an underlying film and a method for self-organizing lithography.

With the miniaturization of structures of various electronic devices such as semiconductor devices and liquid crystal devices, miniaturization of patterns in lithography methods is required. Currently, for example, an ArF excimer laser can be used to form a fine pattern with a line width of about 90 nm, but a finer pattern has been required.

In response to the above demand, a self-organizing lithography method using a so-called self-organizing phase-separated structure in which an ordered pattern is formed spontaneously has been proposed. As such a self-organizing lithography method, a method of forming an ultrafine pattern by self-organization using a block copolymer obtained by copolymerizing a monomer compound having one property and a monomer compound having a different property is known (Japan See Patent Publication No. 2008-149447, Japanese Patent Publication No. 2002-519728, and Japanese Patent Publication No. 2003-218383). According to this method, by annealing the film containing the block copolymer, since polymer structures having the same properties are attempted to be gathered together, 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 known (see US Patent Application Publication No. 2009/0214823 and Japanese Patent Application Publication No. 2010-58403).

In such a self-organizing lithography method, it is known that a film containing a component such as a polymer to be self-organized is formed on another layer, whereby the phase separation due to the self-organization described above effectively occurs in some cases. Various studies have been made on this layer, and when the block copolymer is self-organized, it is supposed that various phase separation structures can be formed by appropriately controlling the surface free energy of the layer (Japanese Patent Laid-Open No. 2008- 36491 and Japanese Patent Laid-Open No. 2012-174984). However, with these conventional methods, it has not yet been reached to form a phase-separated structure by self-organization satisfactorily and to form a rectangular pattern.

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

The present invention has been made on the basis of the above circumstances, and an object of the present invention is to provide a composition for forming an underlying film capable of satisfactorily forming a phase-separated structure by self-organization and forming a rectangular pattern.

The invention made in order to solve the above problems is a composition for forming a base film disposed between a layer containing a silicon atom (hereinafter, also referred to as a ``first layer'') and a self-organizing film in a self-organizing lithography method, and Si -Contains a compound having a group capable of reacting with OH or Si-H (hereinafter, also referred to as "[A] compound") and a solvent (hereinafter, also referred to as "[B] solvent"), and It is a composition for forming an underlying film having a receding contact angle of 70° or more and 90° or less.

Another invention made in order to solve the above problem is a step of forming a base film with a composition for forming a base film on a first layer containing a silicon atom, and a self-assembled film on the side opposite to the first layer of the base film. A self-assembled lithography method comprising a forming step and a step of removing at least a part of the image of the self-assembled film, wherein the base film-forming composition is the base film-forming composition.

Here, the "organic device" means a group containing at least one carbon atom. The "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. This "hydrocarbon group" may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

The "base film" when measuring the receding contact angle is formed by coating the composition for forming a base film on a silicon wafer, forming a film, exposing it with ArF light, and firing at 100°C for 120 seconds.

According to the composition for forming an underlying film and the self-assembly lithography method of the present invention, a phase-separated structure by self-assembly can be formed satisfactorily, and a rectangular pattern can be formed. Therefore, these can be suitably used for a lithography method in the manufacture of various electronic devices such as semiconductor devices and liquid crystal devices in which further miniaturization is required.

1 is a schematic diagram showing an example of a state after forming an underlying film in the self-assembled lithography method of the present invention.
Fig. 2 is a schematic diagram showing an example of a state after forming a pre-pattern on an underlying film in the self-organizing lithography method of the present invention.
Fig. 3 is a schematic diagram showing an example of a state after applying a self-organizing composition to a region on an underlying film partitioned by a preliminary pattern in the self-organizing lithography method of the present invention.
4 is a schematic diagram showing an example of a state after forming a film having a phase-separated structure by self-assembly in a region on an underlying film partitioned by a preliminary pattern in the self-organizing lithography method of the present invention.
5 is a schematic diagram showing an example of a state after removing a partial image and a preliminary pattern of a self-assembled film in the self-assembled lithography method of the present invention.

Hereinafter, an embodiment of the composition for forming an underlying film and a self-assembled lithography method of the present invention will be described in detail.

<Composition for forming an underlying film>

The composition for forming a base film is a composition for forming a base film disposed between a layer containing a silicon atom and a self-organizing film in a self-organizing lithography method, that is, for forming a base film of the first layer for forming a self-organizing film. It is used. The composition for forming an underlying film contains a compound [A] and a solvent [B]. Further, the composition for forming an underlying film may contain an acid generator [C] as a suitable component, and may contain other optional components within a range not impairing the effects of the present invention. In addition, in addition to the polymer, [A] "compound" includes oligomers having a relatively low molecular weight, substances having a hydrocarbon chain, and the like. Hereinafter, each component is demonstrated.

[[A] compound]

[A] The compound is a compound having a group capable of reacting with Si-OH or Si-H. According to the composition for forming an underlying film, since the compound [A] has a group capable of reacting with Si-OH or Si-H, and the receding contact angle of the underlying layer with pure water is 70° or more and 90° or less, for example By the action of oxygen or water in the air, it is possible to firmly bond with the surface of the first layer having Si-OH or Si-H on the surface of the layer containing silicon atoms. As the reason, it is estimated as follows. In the first layer, a group having Si-OH or Si-H is formed on its surface by the action of, for example, oxygen in air, water, or the like. Therefore, the compound [A] aggregates and is not unevenly distributed in the base film, and as a result, by using the composition for forming the base film, a phase-separated structure by self-organization and a rectangular pattern can be formed.

Examples of the group capable of reacting with Si-OH or Si-H include a hydroxy group, a carboxyl group, an amino group, an epoxy group (oxiranyl group, oxetanyl group), an alkoxy group, and a group represented by the following formula (2). Can be lifted.

In the above formula (2), R ^A is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^B is a C 1 to C 20 monovalent oxyhydrocarbon group or a halogen atom. a is an integer of 0 to 2. However, ^{when there are a plurality of R A} and R ^B , respectively, a plurality of R ^A and a plurality of R ^B may be the same or different.

Examples ^{of the monovalent hydrocarbon group having 1 to 20 carbon atoms in R A} include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent hydrocarbon group having 6 to 20 carbon atoms. Aromatic hydrocarbon groups and the like.

As the monovalent chain hydrocarbon group, for example

Alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, and t-butyl group;

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

Alkynyl groups, such as an ethynyl group, a propynyl group, and a butynyl group, etc. are mentioned.

As the monovalent alicyclic hydrocarbon group, for example

Cycloalkyl groups, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, a tricyclodecyl group, and a tetracyclododecyl group;

Cycloalkenyl groups, such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, a norbornenyl group, and a tricyclodecenyl group, etc. are mentioned.

As the monovalent aromatic hydrocarbon group, for example

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

Aralkyl groups, such as a benzyl group, a phenethyl group, a phenylmethyl group, a naphthylmethyl group, and an anthrylmethyl group, etc. are mentioned.

As said R ^A , among these, a monovalent chain hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is still more preferable.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms in ^{R B} include a group in which an oxygen atom is bonded to those exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms of ^{R A.} Among these, a group in which an oxygen atom is bonded to a monovalent chain hydrocarbon group is preferable, an alkoxy group is more preferable, and a methoxy group is still more preferable.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a chlorine atom is preferable.

As said a, 0 or 1 is preferable, and 0 is more preferable.

As the group capable of reacting with Si-OH or Si-H, a hydroxy group, an alkoxy group, and a group represented by the above formula (2) are preferable.

As the lower limit of the receding contact angle of the base film with pure water, 71° is preferable, 72° is more preferable, 73° is still more preferable, and 74° is particularly preferable. On the other hand, as the upper limit of the retraction contact angle, 87° is preferable, 84° is more preferable, 81° is still more preferable, and 78° is particularly preferable. By setting the retreat contact angle in the above range, there is a tendency that a phase-separated structure by self-organization can be better formed, and a more rectangular pattern can be formed.

As the compound [A], a compound represented by the following general formula (1) is preferable.

In the above formula (1), A is a (m+n) valent linking group. D is a monovalent organic group having 10 or more carbon atoms. E is a group capable of reacting with Si-OH or Si-H. m and n are each independently an integer of 1 to 200. However, when m is 2 or more, a plurality of D may be the same or different, and two or more D may be bonded to each other. When n is 2 or more, a plurality of E may be the same or different.

The (m+n) valent linking group represented by A is not particularly limited as long as it is a group connecting the group represented by E and the monovalent organic group represented by D. For example, an organic group having 1 to 30 carbon atoms, the following And groups represented by the general formula (3).

In the general formula (3), Q is a polysiloxane structure having 2 to 100 (m+n) valent silicon atoms. T is a divalent organic group having 1 to 30 carbon atoms bonded to a silicon atom of Q and a carbon atom or an oxygen atom. m and n are synonymous with the above formula (1). * ¹ represents a site bonded to E in the above formula (1). * ² represents a site bonded to D in the above formula (1).

The polysiloxane structure represented by Q is not particularly limited as long as it has a siloxane bond (-Si-O-), but, for example, hydrolysis of a compound containing a hydrolyzable silane compound represented by the following formula (5) The structure derived from a condensate, etc. are mentioned.

In the above formula (5), R ^C is a hydrogen atom or a monovalent organic group. X is a halogen atom or -OR ^D. R ^D is a monovalent organic group. c is an integer from 0 to 3. However, R ^C, and when X is plural, each individual, of R ^C and the plurality may be the same or different, are a plurality of X may be the same or different.

Examples of the ^{monovalent organic group represented by R C} include a monovalent hydrocarbon group having 1 to 30 carbon atoms, a hetero atom-containing group including a group having a hetero atom between carbon and carbon of the hydrocarbon group, the hydrocarbon group and the hetero And groups in which some or all of the hydrogen atoms of the atom-containing group are substituted with a substituent.

Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms include a monovalent chain hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Can be lifted.

As the monovalent chain hydrocarbon group, for example

Alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, and t-butyl group;

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

Alkynyl groups, such as an ethynyl group, a propynyl group, and a butynyl group, etc. are mentioned.

As the monovalent alicyclic hydrocarbon group, for example

Cycloalkyl groups, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, a tricyclodecyl group, and a tetracyclododecyl group;

Cycloalkenyl groups, such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, a norbornenyl group, and a tricyclodecenyl group, etc. are mentioned.

As the monovalent aromatic hydrocarbon group, for example

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

Aralkyl groups, such as a benzyl group, a phenethyl group, a phenylmethyl group, a naphthylmethyl group, and an anthrylmethyl group, etc. are mentioned.

Examples of the hetero atom of the group having a hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom.

Examples of the group having a hetero atom include -O-, -CO-, -NR'-, -S-, and -CS-. R'is a monovalent hydrocarbon group having 1 to 20 carbon atoms.

Examples of the substituent include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxy group, a carboxyl group, a cyano group, and a nitro group.

Examples of the monovalent organic group represented by ^{R D} include groups similar to those exemplified as the monovalent organic group of ^{R C.}

The hydrolyzable silane compound represented by the above formula (5) is a tetrafunctional silane when c is 0, a trifunctional silane when c is 1, a bifunctional silane when c is 2, and c is 3 In the case of, it is a monofunctional silane. As c, among these, 0 and 1 are preferable, and 1 is more preferable.

As the hydrolyzable silane compound represented by the above formula (5), for example

Tetrafunctional silanes such as tetramethoxysilane and tetraethoxysilane;

Methyltrimethoxysilane, methyltriethoxysilane, methyltri i-propoxysilane, methyltri n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri i-propoxysilane, ethyltri n-butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltri Ethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltri Methoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 4-methylphenyltrimethoxysilane, 4-methylphenyltriethoxysilane, 4-t-butoxyphenethyltriethoxysilane, 1-(t-part Toxyphenyl)ethyltriethoxysilane, t-butoxyphenyltriethoxysilane, p-hydroxyphenyltrimethoxysilane, 1-(p-hydroxyphenyl)ethyltrimethoxysilane, 2-(p-hydroxyl) Roxyphenyl)ethyltrimethoxysilane, 4-hydroxy-5-(p-hydroxyphenylcarbonyloxy)pentyltrimethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl Trifunctional silanes such as triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane;

Difunctional silanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiacetoxysilane, din-butyldimethoxysilane, and diphenyldimethoxysilane;

And monofunctional silanes such as trimethylmethoxysilane and trin-butylethoxysilane. These may be used alone or in combination of two or more.

The polysiloxane structure may be a chain structure, a two-dimensional structure such as a planar structure, or a three-dimensional structure such as a silsesquioxane structure, as long as the effect of the present invention is not impaired.

The number of silicon atoms of Q in the general formula (3) is 2 to 100, preferably 2 to 50, and more preferably 2 to 20.

Examples of the divalent organic group having 1 to 30 carbon atoms bonded to the silicon atom of Q represented by T in the formula (3) and a carbon atom or an oxygen atom include -R ¹ -* ² , -OR ^2- * ² etc. are mentioned. R ¹ and R ² are each independently a divalent organic group having 1 to 30 carbon atoms. * ² is the same as the formula (1).

Examples ^{of the divalent organic group having 1 to 30 carbon atoms represented by R 1} and R ² include a divalent chain hydrocarbon group having 1 to 30 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, and 6 to 30 carbon atoms. And a group containing a hetero atom such as an oxygen atom, a nitrogen atom, and a sulfur atom in the divalent aromatic hydrocarbon group of, and the divalent hydrocarbon group structure.

Examples of the divalent chain hydrocarbon group include methanediyl group, ethanediyl group, n-propanediyl group, i-propanediyl group, n-butanediyl group, i-butanediyl group, n-pentanediyl group, i -Pentanediyl group, n-hexanediyl group, i-hexanediyl group, etc. are mentioned.

Examples of the divalent alicyclic hydrocarbon group include a cyclopropanediyl group, a cyclobutanediyl group, a cyclopentanediyl group, a cyclohexanediyl group, a cyclooctanediyl group, a norbornandiyl group, and an adamantanediyl group. have.

Examples of the divalent aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, a toluenediyl group, a phenylethanediyl group, and a xylenediyl group.

Examples of the group containing a hetero atom in the divalent hydrocarbon group structure include 3-butoxypropane-1,2-diyl group and the like.

The ^{number of carbon atoms of R 1} and R ² is 1 to 30, preferably 1 to 20, and more preferably 1 to 10.

Examples of the monovalent organic group having 10 or more carbon atoms represented by D in the general formula (1) include those having 10 or more carbon atoms among the monovalent organic groups exemplified as ^{R C in the general formula (5).}

As the lower limit of the number of carbon atoms in the organic group of D, 10 is preferable, 20 is more preferable, 50 is still more preferable, and 100 is particularly preferable. As the upper limit of the number of carbon atoms, 10,000 is preferable, 5,000 is more preferable, 2,000 is still more preferable, and 1,000 is particularly preferable.

The organic group represented by D is preferably an organic chain having a chain structure, and for example, a group containing a polymerized chain containing a carbon-carbon bond obtained by polymerizing a vinyl monomer or the like, an oligomer, a hydrocarbon chain, and a polyalkyl Renoxide chain, etc. are mentioned. The "polymerization chain including a carbon-carbon bond obtained by polymerizing a vinyl monomer or the like" means a chain (hereinafter, also referred to as a graft chain) composed of a carbon-carbon bond formed by a polymerization reaction, a graft reaction, or the like. Examples of the polymer chain include a polymer chain and an oligomer chain.

As D in the above formula (1), a group containing a polymerized chain containing a carbon-carbon bond is preferable from the viewpoint of ease of production, and a group containing a vinyl polymerized chain is more preferable. Among these, a polymer chain is preferred from the viewpoint of ease of manufacture. The structural units constituting the polymerization chain may be one or two or more types, and the polymerization chain may be linear or branched, and in the case of having two or more types of structural units, each structural unit may be in a random shape. It may have a block shape.

As D in the above formula (1), a group containing a sulfur atom is also preferable. When D in the general formula (1) is a group containing a sulfur atom, it is preferable that D and A in the general formula (1) are bonded via the sulfur atom.

When A is an organic group having 1 to 30 carbon atoms and n is an integer of 1 to 10, E in the formula (1) is, among these, the unevenness of the compound [A] on the first layer can be further suppressed. From a possible viewpoint, a hydroxy group and a group represented by the above formula (2) are preferable.

[A] The compound may have one group capable of reacting with Si-OH or Si-H represented by E in the formula (1), and 2 groups capable of reacting with Si-OH or Si-H You may have more than one.

In addition, as E in the above formula (1), when the linking group represented by A is a group represented by the above formula (3), from the viewpoint of a group capable of more reacting with Si-OH or Si-H among these, A hydroxy group and an alkoxy group are preferred.

In the formula (1), m and n are integers of 1 to 100, preferably 1 to 50, and more preferably 1 to 20.

When A in the formula (1) is an organic group having 1 to 30 carbon atoms, it is preferable that the compound [A] does not have a group containing an active hydrogen other than the group represented by E in the formula (1). . When the compound [A] has a group containing an active hydrogen other than the group represented by E in the general formula (1), the receding contact angle tends to be small.

Examples of the compound [A] represented by the above formula (1) include compounds represented by the following formula (6).

In the formula (6), A, E, m and n have the same meaning as the formula (1). D'is a monovalent organic group having 10 or more carbon atoms. However, when m is 2 or more, a plurality of D'may be the same or different, and two or more D'may be bonded to each other.

Examples of the monovalent organic group having 10 or more carbon atoms represented by D'include groups similar to those exemplified as the monovalent organic group having 10 or more carbon atoms represented by D.

[A] compound is represented by the above formula (6), when A is an organic group having 1 to 30 carbon atoms, and D'is an organic chain, the terminal of the organic chain is The sulfur atom may be bonded, or may be bonded other than the terminal. Here, the "terminal of an organic chain" means an atom located at the end of the longest of the atomic chains constituting the organic chain.

The [A] compound represented by the above formula (6) has one group capable of reacting with Si-OH or Si-H from the viewpoint of further suppressing unevenness on the first layer of the compound [A]. It is preferable that D'is an organic chain, and it is more preferable that a sulfur atom is bonded to the terminal of this organic chain. In this case, the compound [A] tends to be arranged in a brush shape on the first layer.

The lower limit of the content of the compound [A] is preferably 70% by mass, more preferably 80% by mass, and still more preferably 85% by mass, based on the total solid content of the composition for forming a base film. In addition, the compound [A] may be used alone or in combination of two or more.

[Method for producing compound [A]]

[A] As a method for producing the compound, for example, radical polymerization, radical polymerization using a chain transfer agent, living radical polymerization such as atomic transfer radical polymerization (ATRP), polymerization such as cationic polymerization and anionic polymerization, and known organic compounds Synthesis method of, etc. are mentioned. Among these, radical polymerization using a chain transfer agent is preferred from the viewpoint of ease of production.

[A] The compound is, for example, represented by the formula (1), and when D in the formula (1) contains a sulfur atom, more specifically represented by the formula (6), For example, a vinyl monomer is radically polymerized in the presence of a chain transfer agent represented by the following formula (4), and for example, the vinyl monomer is radically polymerized in the presence of a chain transfer agent represented by the following formula (4). It can be obtained by an equipped manufacturing method.

In the formula (4), A, E, m and n have the same meaning as the formula (1).

The chain transfer agent may be synthesized according to a known manufacturing method, or a commercially available product may be used.

The chain transfer agent, for example

It can be obtained by a production method including a step of reacting a silane compound having a mercapto group and a silane compound not having a mercapto group in the presence of an acid or a base.

Examples of the silane compound having a mercapto group include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane. Among these, 3-mercaptopropyltrimethoxysilane is preferable.

As the silane compound having no mercapto group, for example, n-butyltrimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyl Triethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-decyltrimethoxysilane, trifluoropropyltrimethoxysilane, and the like. Among these, n-butyltrimethoxysilane and methyltrimethoxysilane are preferred.

Examples of the acid include oxalic acid, hydrochloric acid, and sulfuric acid. Among these, oxalic acid is preferred. Examples of the base include alkali hydroxides such as sodium hydroxide and nitrogen-containing compounds such as amine compounds such as triethylamine.

As the lower limit of the weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the chain transfer agent, 100 is preferable, 200 is more preferable, and 300 is still more preferable. The upper limit of Mw of the chain transfer agent is preferably 20,000, more preferably 15,000, and even more preferably 10,000. By setting Mw of the chain transfer agent to the above range, the uneven distribution of the chain transfer agent tends to be further reduced.

The lower limit of the number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography (GPC) of the chain transfer agent is preferably 50, more preferably 100, and even more preferably 150. As the upper limit of Mn of the chain transfer agent, 10,000 is preferable, 7,500 is more preferable, and 5,000 is still more preferable. By setting Mn of the chain transfer agent to the above range, the uneven distribution of the chain transfer agent tends to be further reduced.

The lower limit of the ratio of Mw (Mw/Mn) to the number average molecular weight (Mn) in terms of polystyrene by GPC of the chain transfer agent is preferably 1. As the upper limit of Mw/Mn of the chain transfer agent, 5 is preferable, 4 is more preferable, and 3 is still more preferable.

In the present specification, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are GPC columns (two "G2000HXL" of Tosoh Corporation, one "G3000HXL" and one "G4000HXL"), and flow rate: 1.0 It was measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of mL/min, elution solvent: tetrahydrofuran, column temperature: 40°C.

As the vinyl monomer, that is, a vinyl monomer that imparts a graft chain represented by D in the general formula (1), for example

Olefinic monomers such as ethylene, propylene, butene, pentene, hexene, and heptene;

Vinyl aromatic monomers such as styrene, vinyl naphthalene, vinyl biphenyl, and α-methylstyrene;

Methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate And aliphatic (meth)acrylates such as 2-acetoacetoxyethyl (meth)acrylate;

Cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxy (meth) Alicyclic (meth)acrylates such as acrylate, dicyclopentanyl (meth)acrylate, norbornyl (meth)acrylate, and adamantyl (meth)acrylate;

Aromatic (meth)acrylates such as benzyl (meth)acrylate, phenyl (meth)acrylate, and naphthyl (meth)acrylate;

Halogen-based monomers such as vinyl fluoride, vinyl chloride, vinyl bromide, vinyl iodide, vinylidene fluoride, and vinylidene chloride;

Carboxylic acid-based monomers such as (meth)acrylic acid and maleic acid;

And monomers having polar groups such as an acid anhydride group, a phosphoric acid group, a sulfonic acid group, a hydroxy group, an aldehyde group, an amino group, an amide group, an epoxy group, an acetacetoxy group, an isocyanate group, and an isothiocyanate group.

As the vinyl monomer, vinyl aromatic monomer, aliphatic (meth) acrylate and aromatic (meth) acrylate are preferable from the viewpoint of more ubiquitous distribution of the [A] compound among these, and styrene, methyl methacrylate, and cyclohexyl methacryl Rate and dicyclopentanylmethacrylate are more preferred.

For example, by adjusting the ratio of the use of the polarity and the non-polar as vinyl monomers, the compound [A] capable of setting the receding contact angle of the film formed by the composition for forming the underlying film into a predetermined range can be synthesized. have.

As a radical polymerization initiator, for example

Azobisisobutyronitrile (AIBN), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2-cyclopropylpropionitrile), Azo radical initiators such as 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, and 2,2'-azobis (2-methylpropionitrile) ;

And peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and t-butyl peroxy-2-ethylhexanoate. These may be used alone or in combination of two or more.

Examples of the radical polymerization initiator include 2,2'-azobis(2-methylpropionitrile), t-butylperoxy-2-ethylhexanoate, and 2,2'-azobis(2,4-dimethylvale). Ronitrile) is preferred.

As a solvent used for polymerization, for example

alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;

Cycloalkanes, such as cyclohexane, cycloheptane, cyclooctane, decalin, and norbornane;

Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and cumene;

Halogenated hydrocarbons such as chlorobutanes, bromohexane, dichloroethane, hexamethylenedibromide, and chlorobenzene;

Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, and methyl propionate;

Ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, and 2-heptanone;

Ethers such as tetrahydrofuran, dimethoxyethane, and diethoxyethane;

Alcohols, such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol, etc. are mentioned. These may be used alone or in combination of two or more.

As a solvent used for polymerization, ketones are preferable among these, and methyl ethyl ketone is more preferable.

As the lower limit of the reaction temperature in polymerization, 40°C is preferable, and 50°C is more preferable. The upper limit of the reaction temperature is preferably 150°C, and more preferably 120°C. On the other hand, as the lower limit of the reaction time, 1 hour is preferable. As the upper limit of the reaction time, 48 hours are preferable, and 24 hours are more preferable.

The reaction solution after polymerization is preferably diluted in a solution of 5% by mass or more and 15% by mass or less as a solid content concentration with a solvent such as propylene glycol monomethyl ether acetate in consideration of the handling surface.

The compound [A] represented by the above formula (1) is an organic group of D, and preferably has a group containing a polymerized chain including a carbon-carbon bond. Examples of the group containing the polymer chain include a group containing a polymer chain and a group containing an oligomer chain. Among these, from the viewpoint of further suppressing the unevenness of the compound [A], a group containing a polymer chain is preferable, and a group containing a polymer chain formed of a vinyl monomer is more preferable. That is, as the compound [A], a graft polymer having a graft chain formed of a vinyl monomer is preferable.

As the lower limit of the weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the compound [A], 1,000 is preferable, 2,000 is more preferable, and 3,000 is still more preferable. As the upper limit of the Mw, 50,000 is preferable, 30,000 is more preferable, and 20,000 is still more preferable. By making Mw of the compound [A] in the above range, there is a tendency that the uneven distribution of the compound [A] is further reduced.

As the lower limit of the number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography (GPC) of the compound [A], 900 is preferable, 1,900 is more preferable, and 2,900 is still more preferable. As the upper limit of the Mn, 49,000 is preferable, 29,000 is more preferable, and 19,000 is still more preferable. By making Mw of the compound [A] in the above range, there is a tendency that the uneven distribution of the compound [A] is further reduced.

As the lower limit of the ratio (Mw/Mn) of Mw to the number average molecular weight (Mn) in terms of polystyrene by GPC of the compound [A], 1 is preferable. As the upper limit of the Mw/Mn, 5 is preferable, 3 is more preferable, and 2.5 is still more preferable.

[[B] solvent]

The composition for forming an underlying film contains a solvent [B]. 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.

As an alcohol-based solvent, for example

Aliphatic monoalcohol 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 solvents having 3 to 19 carbon atoms such as propylene glycol monomethyl ether.

As an ether 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 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 , Chain ketone solvents such as methyl-n-hexyl ketone, di-iso-butyl ketone, and trimethylnonanone:

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

2,4-pentanedione, acetonyl acetone, acetophenone, etc. are mentioned.

Examples of the amide solvent include 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

Monocarboxylic acid ester solvents such as butyl acetate, ethyl lactate, and butoxymethyl acetate;

Polyhydric alcohol carboxylate solvents such as propylene glycol acetate;

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

Polyhydric carboxylic acid diester solvents such as diethyl oxalate;

And carbonate solvents such as dimethyl carbonate and diethyl 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 solvents having 6 to 16 carbon atoms such as toluene and xylene.

These may be used alone or in combination of two or more.

[B] As the solvent, among these, alcohol-based solvents, ester-based solvents and ketone-based solvents are preferable, and polyhydric alcohol partial ether-based solvents having 3 to 19 carbon atoms, monocarboxylic acid ester-based solvents, and cyclic ketone-based solvents are more preferable. Further, propylene glycol monomethyl ether acetate, butoxymethyl acetate, butyl acetate and cyclohexanone are more preferable.

As the lower limit of the content of the solvent [B], 500 parts by mass is preferable, more preferably 1,000 parts by mass, and even more preferably 2,000 parts by mass per 100 parts by mass of the compound [A]. On the other hand, the upper limit of the content of the solvent [B] is preferably 50,000 parts by mass, more preferably 30,000 parts by mass, and still more preferably 20,000 parts by mass per 100 parts by mass of the compound [A]. By setting the content of the solvent [B] in the above range, the compound [A] can be further dispersed in the solvent [B].

[[C] acid generator]

[C] The acid generator is a component that generates an acid by exposure or heating. The composition for forming a base film can accelerate the reaction of the [A] compound with Si-OH or Si-H by containing the [C] acid generator, and as a result, further suppress the uneven distribution of the [A] compound, A phase-separated structure by self-organization can be better formed, and a rectangular pattern can be formed.

[C] As an acid generator, for example

Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium 2-(adamantan-1-ylcarbonyloxy)-1,1,3,3,3-pentafluoropropane-1-sulfonate, Triphenylsulfonium norbornansultone-2-yloxycarbonyldifluoromethanesulfonate, triphenylsulfoniumpiperidin-1-ylsulfonyl-1,1,2,2,3,3-hexafluoropropane- 1-sulfonate, triphenylsulfoniumadamantan-1-yloxycarbonyldifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfoniumcampasulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro Sulfonium salts, such as -n-butanesulfonate and triphenylsulfonium 2-(bicyclo[2.2.1]hept-2-yl)-1,1,2,2-tetrafluoroethane-1-sulfonate;

1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiopheniumtrifluoromethanesulfonate, 1-(6-n-butoxynaphthalen-1-yl)tetrahydrothiophenium 2-bi Cyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethane-1-sulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium Tetrahydrothiophenium salts such as campasulfonate;

N-(trifluoromethanesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(camposulfonyloxy)bicyclo[2.2.1]hept-5 N-sulfonyloxyimide compounds, such as -ene-2,3-dicarboxyimide;

Diphenyliodonium trifluoromethanesulfonate, bis(4-t-butylphenyl)iodoniumtrifluoromethanesulfonate, bis(4-t-butylphenyl)iodonium nonafluoro-n-butane And iodonium salts such as sulfonate and 4-methoxyphenylphenyl iodonium campasulfonate.

These may be used alone or in combination of two or more.

[C] As the anion species contained in the acid generator, a fluorinated sulfonic acid anion is preferable.

[C] As the cationic species contained in the acid generator, a sulfonium cation and an iodonium cation are preferable.

[C] As the acid generator, a sulfonium salt and an iodonium salt are preferable.

When the composition for forming a base film contains an acid generator [C], the lower limit of the content of the acid generator [C] is preferably 0.1 parts by mass, more preferably 0.5 parts by mass based on 100 parts by mass of the compound [A]. Do. On the other hand, as the upper limit of the content of the acid generator [C], 30 parts by mass is preferable, and 20 parts by mass is more preferable with respect to 100 parts by mass of the compound [A]. [C] By setting the content of the acid generator in the above range, the unevenness of the compound [A] can be further suppressed, and as a result, a phase-separated structure due to self-organization can be more favorably formed, and a rectangular pattern can be further formed. have.

[Other optional ingredients]

The composition for forming an underlying film may contain other optional components in addition to the above components. As said other optional component, surfactant etc. are mentioned, for example.

[Surfactants]

The surfactant is a component capable of improving the coating property to a first layer such as a substrate. The upper limit of the content of the surfactant is preferably 2 parts by mass, more preferably 1.5 parts by mass per 100 parts by mass of the compound [A].

<Method for producing a composition for forming an underlying film>

The composition for forming a base film can be produced, for example, by mixing a compound [A], a solvent [B], and an acid generator [C] as necessary in a predetermined ratio. In addition, as the lower limit of the solid content concentration of the composition for forming a base film, 0.01 mass% is preferable, and 0.1 mass% is more preferable. The upper limit of the solid content concentration is preferably 30% by mass, more preferably 10% by mass.

<Self-Organizing Lithography Method>

Directed Self Assembly refers to a phenomenon in which an organization or structure is built spontaneously, not only due to control from external factors. A film (self-organizing film) having a phase-separated structure by self-organization is formed on a specific base, for example, by applying a self-organizing composition, and a part of the image in the self-organizing film is removed, Self-organizing patterns can be formed.

The self-assembled lithography method includes, for example, a step of forming a base film with a composition for forming a base film on a first layer containing a silicon atom (hereinafter, also referred to as a ``base film forming step''), and the first layer of the base film. A step of forming a self-organizing film on the side opposite to the first layer (hereinafter, also referred to as ``self-organizing film forming step'') and a step of removing at least a part of the image of the self-organizing film (hereinafter also referred to as ``removing step'') And the composition for forming the underlying film is the composition for forming the underlying film.

The self-assembled lithography method is a surface of the underlayer opposite to the first layer between the base layer forming process and the self-assembled layer forming process, that is, after the underlayer forming process and before the self-assembled layer forming process, for example, the underlayer. A step of forming a pre-pattern using a composition for pre-pattern formation on the first layer formed by the film (hereinafter, also referred to as a “pre-pattern forming step”) may be provided.

The self-assembled lithography method may include a step of patterning the first layer after the removal step (hereinafter, also referred to as "the first layer patterning step"). Hereinafter, each process when the first layer is a substrate will be described with reference to FIGS. 1 to 5.

[Base film formation process]

In this step, an underlying film is formed on the substrate 101 by using the composition for forming an underlying film. By performing this process, as shown in FIG. 1, a substrate 101 having an underlying film 102 on the substrate 101, that is, a substrate 101 having an underlying film formed thereon is obtained. The self-assembled film 105 is formed by laminating on the underlying film 102. In the self-assembled film 105, when the phase-separated structure (microdomain structure) is formed, the substrate 101 is formed as an underlying film, so that the structure can be controlled, and a phase-separated structure by self-organization can be formed simply and satisfactorily. It is possible to form a rectangular pattern or the like.

The substrate 101 used in the self-organizing lithography method is not particularly limited as long as it contains a silicon atom, and examples thereof include a silicon atom-containing substrate such as a silicon wafer, a metal substrate having a siloxane film, and the like. A silicon atom-containing substrate is preferable, and a silicon wafer is more preferable. Further, the substrate 101 usually has Si-OH or Si-H on its surface due to the action of oxygen or water in the air. Further, the substrate 101 may have Si-OH or Si-H on its surface by performing a surface treatment with an acid such as sulfuric acid.

Although it does not specifically limit as the said base film formation method, For example, the method of hardening by heating or exposing the coating film formed by coating the said base film formation composition on the board|substrate 101 by a well-known method, such as a spin coating method, etc. Can be mentioned. Examples of the radiation used for this exposure include visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, γ-ray, molecular beam, and ion beam.

The lower limit of the temperature when heating the coating film is preferably 100°C, and more preferably 120°C. As the upper limit of the temperature, 400°C is preferable, and 350°C is more preferable. The lower limit of the time when heating the coating film is preferably 10 seconds, and more preferably 30 seconds. As the upper limit of the time, 600 seconds is preferable, and 300 seconds is more preferable. By setting the heating temperature and time at the time of forming the base film to the above ranges, uneven distribution of the compound [A] can be further suppressed. The atmosphere for heating the coating film is not particularly limited, but may be under an air atmosphere or an inert gas atmosphere such as nitrogen gas. Further, after heating the coating film, solvent washing may be performed.

The lower limit of the average film thickness of the underlying film 102 is preferably 0.5 nm, more preferably 1 nm, and even more preferably 5 nm. As the upper limit of the average film thickness, 2,000 nm is preferable, 100 nm is more preferable, and 50 nm is still more preferable.

[Pre-pattern formation process]

In this process, as shown in FIG. 2, a preliminary pattern 103 is formed on the base layer 102 by using the composition for forming a preliminary pattern. By performing this step, the phase separation at the time of forming the self-assembled film 105 is further controlled, and a phase-separated structure by self-assembly can be better formed. That is, among the components forming the self-organizing film 105, components having high affinity with the side surfaces of the preliminary pattern 103 form an image along the preliminary pattern 103, and components with low affinity are preliminary. An image is formed at a position spaced apart from the pattern 103. Thereby, a phase-separated structure by self-organization can be formed more favorably. In addition, depending on the material, length, thickness, shape, etc. of the preliminary pattern 103, the formed phase separation structure can be finely controlled. Further, the preliminary pattern 103 may be partially modified by partial exposure, laser ablation, or the like. In addition, as the preliminary pattern 103, it can be appropriately selected according to the pattern to be finally formed, and for example, a line and space pattern, a hole pattern, a column pattern, or the like can be used.

As a method of forming the preliminary pattern 103, a method similar to a known method of forming a resist pattern can be used. In addition, as the composition for forming the preliminary pattern, a conventional composition for forming a resist film can be used. As a specific method of forming the preliminary pattern 103, for example, a chemically amplified resist composition such as "ARX2928JN" from JSR is used, and a resist film is formed by applying it on the base film 102. Subsequently, radiation is irradiated to a desired region of the resist film through a mask having a specific pattern to perform exposure. Examples of the radiation include far ultraviolet rays such as ArF excimer laser light and KrF excimer laser light, electromagnetic waves such as ultraviolet rays and X-rays, and charged particle rays such as electron rays. Among these, far ultraviolet rays are preferable, ArF excimer laser light and KrF excimer laser light are more preferable, and ArF excimer laser light is still more preferable. Subsequently, baking (PEB) is performed after exposure, and development is performed using a developer such as an alkali developer, so that a desired preliminary pattern 103 can be formed.

In addition, the surface of the preliminary pattern 103 may be subjected to hydrophobic treatment or hydrophilic treatment. As a specific treatment method, a hydrogenation treatment or the like in which hydrogen plasma is exposed for a certain period of time may be mentioned. By increasing the hydrophobicity or hydrophilicity of the surface of the preliminary pattern 103, the above-described self-organization may be promoted.

[Self-organizing film formation process]

In this step, a self-assembled film 105 is formed on the base film 102. By performing this step, a substrate in which the self-assembled film 105 is formed on the base film 102 can be obtained. In the formation of the self-organizing film 105, for example, a self-organizing composition containing a component capable of forming a phase-separated structure by self-organization is applied onto the base film 102 to form a coating film. This can be carried out by self-organizing the above components in the composition. In addition, in the case of using the preliminary pattern 103, as shown in FIG. 3, in the non-laminated region of the preliminary pattern 103, that is, the region on the underlying film 102 partitioned by the preliminary pattern 103. , By applying the self-organizing composition to form a coating film, as shown in FIG. 4, to form a self-organizing film 105 having a phase-separated structure.

In the formation of the self-organizing film 105, the self-organizing composition is applied on the base film 102 to form a coating film, and then annealing or the like is performed to accumulate parts having the same properties and form an ordered pattern. It can promote so-called self-organization. As a result, a self-assembled film 105 having a phase-separated structure is formed on the underlying film 102. The phase separation structure is preferably formed along the preliminary pattern 103, and the interface formed by the phase separation is more preferably substantially parallel to the side surface of the preliminary pattern 103. For example, when the preliminary pattern 103 is a line pattern, an image such as a component having a higher affinity with the preliminary pattern 103 is formed along the preliminary pattern 103 (105b), and the other component The image of the back is formed at the part farthest from the side of the preliminary pattern 103, that is, in the central part of the area divided by the preliminary pattern 103 (105a), and the lamella phase separation structure in which the lamella (plate) images are alternately arranged To form. When the preliminary pattern 103 is a hole pattern, an image such as a component having high affinity with the preliminary pattern 103 is formed along the side of the hole of the preliminary pattern 103, and the other side is formed at the center of the hole. A phase such as an ingredient is formed. In addition, when the preliminary pattern 103 is a pillar pattern, an image such as a component having higher affinity with the preliminary pattern 103 is formed along the side surface of the pillar of the preliminary pattern 103, and from each pillar In the spaced part, a phase such as the other component is formed. A desired phase-separated structure can be formed by appropriately adjusting the distance between the pillars of the preliminary pattern 103, the structure of the components such as each polymer in the self-organizing composition, and the blending ratio. In addition, the phase separation structure formed in the present process includes a plurality of phases, and the interface formed by these phases is usually approximately vertical, but the interface itself may not necessarily be clear. In this way, the phase separation structure obtained is precisely controlled by the component structure of each compound, the compounding ratio, and the preliminary pattern 103 in addition to the base film 102, and a more desired fine pattern can be obtained.

The component capable of forming a phase-separated structure by self-assembly is not particularly limited as long as it has such properties, and examples thereof include a block copolymer and a mixture of two or more types of polymers incompatible with each other. Among these, from the viewpoint of better forming a phase-separated structure, a block copolymer is preferable, a block copolymer containing a styrene unit-methacrylic acid ester unit is more preferable, and a styrene unit-methylmethacrylate unit is used. The containing diblock copolymer is more preferable.

A method of forming the coating film 104 by applying the self-organizing composition on a substrate is not particularly limited, and examples thereof include a method of applying the self-organizing composition by spin coating or the like. Thereby, the self-organizing composition is applied between the preliminary patterns 103 on the base film 102 and the like to form a coating film 104.

As an annealing method, a method of heating at a temperature of preferably 80°C or more and 400°C or less, and more preferably 80°C or more and 300°C or less using an oven, a hot plate, or the like may be mentioned. As the lower limit of the annealing time, 10 seconds is preferable, and 30 seconds is more preferable. As the upper limit of the annealing time, 120 minutes is preferable, and 60 minutes is more preferable. As the lower limit of the average film thickness of the self-assembled film 105 thus obtained, 0.1 nm is preferable, and 0.5 nm is more preferable. As the upper limit of the average film thickness, 500 nm is preferable, and 100 nm is more preferable.

[Removal process]

In this step, as shown in FIGS. 4 and 5, at least a part of the image of the self-assembled film 105 is removed. By performing this step, a part of the phase 105a of the phase separation structure of the self-assembled film 105 can be removed. Some of the phases can be removed by etching treatment using a difference in the etching rate of each phase separated by self-assembly and the like. In this case, the preliminary pattern 103 may be similarly or separately removed. Fig. 5 shows a state after removing some of the phases 105a and the preliminary pattern 103 in the phase separation structure.

Examples of a method for removing a part of the phase 105a or the preliminary pattern 103 in the phase-separated structure of the self-assembled film 105 include reactive ion etching (RIE) such as chemical dry etching and chemical wet etching; Known methods such as physical etching such as sputter etching and ion beam etching are mentioned. 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 liquid etching solutions such as hydrofluoric acid Chemical wet etching (wet development) using is more preferable.

[First layer patterning process (substrate patterning process)]

In this step, a substrate pattern is formed. By performing this step, patterning can be performed by using a pattern including the image 105b of a part of the remaining phase separation film as a mask, and etching the underlying film 102 and the substrate. After the patterning on the substrate is completed, the image used as the mask is removed from the substrate by a dissolution treatment or the like, so that a finally patterned substrate (pattern) can be obtained. As the pattern obtained, a line and space pattern, a hole pattern, etc. are mentioned, for example. As the etching method, a method similar to the removal step can be used, and the etching gas and the etching solution can be appropriately selected according to the materials of the underlying film 102 and the substrate. For example, when the substrate is a silicon material, a mixture gas of a _{freon-based gas and SF 4 can be used.} In addition, when the substrate is a metal film, a mixed gas of _{BCl 3} and Cl _{2 can be used.} The pattern obtained by the self-assembled lithography method is suitably used for semiconductor devices and the like, and the semiconductor devices are widely used for LEDs, solar cells, and the like.

In the present embodiment, a case where the first layer is a substrate has been described as an example, but the first layer is not particularly limited, and for example, a layer containing a silicon atom formed on the substrate may be referred to as a first layer.

In addition, in this embodiment, a film having a phase-separated structure was formed by annealing, but the method of forming the self-assembled film is not particularly limited, and for example, a method of forming a self-organizing film not only due to control from external factors but also spontaneous have.

<Example>

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. The measuring 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", one "G3000HXL" and one "G4000HXL" manufactured by Tosoh), flow rate: 1.0 mL/min, elution solvent: tetrahydrofuran, column temperature: 40°C under analysis conditions , Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard.

[ ¹³ C-NMR analysis]

¹³ C-NMR analysis was performed using "JNM-EX400" manufactured by Nihon Denshi, and 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.}

<Preparation of compound, chain transfer agent and polymer>

The method for producing a chain transfer agent, a compound, and a polymer used in Examples and Comparative Examples is shown below.

[Synthesis Example 1] (Preparation of Compound (A-1))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heated to 85°C, and at the same temperature, a mixed solution of 100 g of methyl ethyl ketone, 51 g (0.49 mol) of styrene, 49 g (0.49 mol) of methyl methacrylate, and 3 g (0.027 mol) of mercapto-1,2-propanediol and A mixed solution of 3 g of 2,2'-azobis (2,4-dimethylvaleronitrile) and 100 g of methyl ethyl ketone as a radical polymerization initiator was added dropwise over 3 hours, respectively, and polymerization was performed for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-1). To obtain a solution. Mw of compound (A-1) was 7,285, Mn was 5,465, and Mw/Mn was 1.33.

[Synthesis Example 2] (Preparation of Compound (A-2))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heating to 85° C., and at the same temperature, 100 g of methyl ethyl ketone, 46 g (0.442 mol) of styrene, 49 g (0.489 mol) of methyl methacrylate, 5 g (0.035 mol) of glycidyl methacrylate, and mercapto-1,2 -A mixed solution of 3 g (0.027 mol) of propanediol and a mixed solution of 3 g of 2,2'-azobis (2-methylpropionitrile) and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively, and this temperature was maintained. It polymerized for 3 hours. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-2). To obtain a solution. Mw of compound (A-2) was 6,715, Mn was 4,874, and Mw/Mn was 1.38.

[Synthesis Example 3] (Preparation of Compound (A-3))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heat to 85°C, and at the same temperature, in a mixed solution of 100 g of methyl ethyl ketone, 51 g (0.49 mol) of styrene, 49 g (0.49 mol) of methyl methacrylate and 3 g (0.027 mol) of mercapto-1,2-propanediol A mixed solution of 4 g of Nichiyu's "perbutyl O" (t-butylperoxy-2-ethylhexanoate) and 100 g of methyl ethyl ketone was added dropwise over 3 hours, respectively, and polymerization was carried out for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-3). To obtain a solution. Mw of compound (A-3) was 6,802, Mn was 4,834, and Mw/Mn was 1.41.

[Synthesis Example 4] (Preparation of Compound (A-4))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heated to 85° C., and at the same temperature, 100 g of methyl ethyl ketone, 48 g (0.46 mol) of styrene, 46 g (0.46 mol) of methyl methacrylate, 6 g (0.036 mol) of cyclohexyl methacrylate, and 9-mercapto-1- A mixed solution of 4.9 g (0.027 mol) of nonanol and a mixed solution of 3 g of 2,2'-azobis (2,4-dimethylvaleronitrile) and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively, and this temperature was It was polymerized for 3 hours while maintaining. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-4). To obtain a solution. Mw of compound (A-4) was 7,132, Mn was 5,465, and Mw/Mn was 1.31.

[Synthesis Example 5] (Preparation of Compound (A-5))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heated to 85°C, and at the same temperature, a mixed solution of 100 g of methyl ethyl ketone, 51 g (0.49 mol) of styrene, 49 g (0.49 mol) of methyl methacrylate and 5.3 g (0.027 mol) of 3-mercaptopropyltrimethoxysilane A mixed solution of 3 g of and 2,2'-azobis (2,4-dimethylvaleronitrile) and 100 g of methyl ethyl ketone was added dropwise over 3 hours, respectively, and polymerization was carried out for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-5). To obtain a solution. Mw of compound (A-5) was 7,048, Mn was 5,121, and Mw/Mn was 1.38.

[Synthesis Example 6] (Preparation of Compound (A-6))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heat to 85°C and at the same temperature, methyl ethyl ketone 100 g, styrene 48 g (0.46 mol), methyl methacrylate 46 g (0.46 mol), dicyclopentanyl methacrylate 6 g (0.027 mol) and 3-mercaptopropyl dimethacrylate A mixed solution of 4.9 g (0.027 mol) of oxymethylsilane and a mixed solution of 3 g of 2,2'-azobis (2,4-dimethylvaleronitrile) and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively, at this temperature. It was polymerized for 3 hours while maintaining. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-6). To obtain a solution. Mw of compound (A-6) was 7,197, Mn was 5,063, and Mw/Mn was 1.42.

[Synthesis Example 7] (Preparation of Compound (A-7))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heated to 85°C, and at the same temperature, a mixed solution of 100 g of methyl ethyl ketone, 51 g (0.49 mol) of styrene, 49 g (0.49 mol) of methyl methacrylate, and 5.5 g (0.027 mol) of mercaptoundecene and 2,2' -A mixed solution of 3 g of azobis (2,4-dimethylvaleronitrile) and 100 g of methyl ethyl ketone was added dropwise over 3 hours, respectively, and polymerization was performed for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-7). To obtain a solution. Mw of compound (A-7) was 7,201, Mn was 5,114, and Mw/Mn was 1.41.

[Synthesis Example 8] (Preparation of Compound (A-8))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. After heating to 85° C., at the same temperature, a mixed solution of 100 g of methyl ethyl ketone, 100 g (1.00 mol) of styrene, 8 g of Nichiyu's “Perbutyl O” and 100 g of methyl ethyl ketone was added dropwise over 3 hours, respectively, at this temperature. It was polymerized for 3 hours while maintaining. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-8). To obtain a solution. Mw of compound (A-8) was 7,365, Mn was 5,312, and Mw/Mn was 1.39.

[Synthesis Example 9] (Preparation of Compound (A-9))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heated to 85°C, at the same temperature, a mixed solution of 100 g of methyl ethyl ketone, 100 g (1.00 mol) of methyl methacrylate, 8 g of "Perbutyl O" manufactured by Nichiyu and 100 g of methyl ethyl ketone was added dropwise over 3 hours, respectively. , Polymerization was carried out for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-9). To obtain a solution. Mw of compound (A-9) was 7,732, Mn was 5,862, and Mw/Mn was 1.32.

[Synthesis Example 10] (Preparation of Compound (A-10))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heated to 85° C., and at the same temperature, methyl ethyl ketone 100 g, styrene 45 g (0.43 mol), methyl methacrylate 43 g (0.43 mol), 2-acetoacetoxyethyl methacrylate 12 g (0.056 mol) and 3-mer A mixed solution of 5.3 g (0.027 mol) of captopropyltrimethoxysilane and a mixed solution of 3 g of 2,2'-azobis (2,4-dimethylvaleronitrile) and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively. , Polymerization was carried out for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-11). To obtain a solution. Mw of compound (A-11) was 7,045, Mn was 5,076, and Mw/Mn was 1.39.

[Synthesis Example 11] (Production of chain transfer agent (a-1))

In a nitrogen atmosphere, 32.6 g (0.166 mol) of 3-mercaptopropyltrimethoxysilane and 31.9 g (0.179 mol) of n-butyltrimethoxysilane were added to a three-necked flask, and 100 g of methyl isobutyl ketone was added and dissolved, The obtained solution was heated to 60°C while stirring with a magnetic stir bar. To this solution, 8.6 g of oxalic acid aqueous solution containing 1% by mass of oxalic acid was continuously added over 1 hour, followed by reaction at 60°C for 4 hours. Then, water, methanol, and methyl isobutyl ketone were distilled off under reduced pressure. The obtained product was dissolved in toluene, washed with water three times with a separating funnel, dehydrated using a desiccant, toluene was distilled off under reduced pressure, and then diluted with propylene glycol monomethyl ether acetate, and a 10% by mass chain transfer agent ( A solution containing a-1) was obtained. The chain transfer agent (a-1) had Mw of 2,615, Mn of 1,214, and Mw/Mn of 2.15. When the IR spectrum was measured about the obtained chain transfer agent, absorption derived from a silanol group was confirmed at ^{3750 cm -1.}

[Synthesis Example 12] (Production of chain transfer agent (a-2))

In a nitrogen atmosphere, 32.6 g (0.166 mol) of 3-mercaptopropyltrimethoxysilane and 24.4 g (0.179 mol) of methyltrimethoxysilane were added to a three-necked flask, and 100 g of methyl isobutyl ketone was added and dissolved. Was heated to 60° C. while stirring with a magnetic stir bar. To this solution, 8.6 g of oxalic acid aqueous solution containing 1% by mass of oxalic acid was continuously added over 1 hour, followed by reaction at 60°C for 4 hours. Then, water, methanol, and methyl isobutyl ketone were distilled off under reduced pressure. The obtained product was dissolved in toluene, washed with water three times with a separating funnel, dehydrated using a desiccant, toluene was distilled off under reduced pressure, and then diluted with propylene glycol monomethyl ether acetate, and a 10% by mass chain transfer agent ( A solution containing a-2) was obtained. The chain transfer agent (a-2) had Mw of 2,738, Mn of 1,241, and Mw/Mn of 2.21. When the IR spectrum was measured about the obtained chain transfer agent, absorption derived from a silanol group was confirmed at ^{3750 cm -1.}

[Synthesis Example 13] (Preparation of Compound (A-11))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Mixing of 30 g of a solution containing 100 g of methyl ethyl ketone, 51 g (0.49 mol) of styrene, 49 g (0.49 mol) of methyl methacrylate, and 10% by mass of a chain transfer agent (a-1) by heating to 85°C and at the same temperature The solution, a mixed solution of 3 g of 2,2'-azobis(2-methylpropionitrile) and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively, and polymerization was carried out for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-1). To obtain a solution. Mw of compound (A-1) was 8,280, Mn was 4,465, and Mw/Mn was 1.84.

[Synthesis Example 14] (Preparation of Compound (A-12))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Mixing of 30 g of a solution containing 100 g of methyl ethyl ketone, 51 g (0.49 mol) of styrene, 49 g (0.49 mol) of methyl methacrylate, and 10% by mass of a chain transfer agent (a-1) by heating to 85°C and at the same temperature A mixed solution of 4 g of the solution and Nichiyu's 「Perbutyl O」 (t-butylperoxy-2-ethylhexanoate) and 100 g of methyl ethyl ketone was added dropwise over 3 hours, and the polymerization was maintained at this temperature for 3 hours. did. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-2). To obtain a solution. Mw of compound (A-2) was 7,880, Mn was 4,267, and Mw/Mn was 1.85.

[Synthesis Example 15] (Preparation of Compound (A-13))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heat to 85°C and at the same temperature, methyl ethyl ketone 100 g, styrene 48 g (0.46 mol), methyl methacrylate 46 g (0.46 mol), dicyclopentanyl methacrylate 6 g (0.027 mol), 10 mass% chain transfer agent A mixed solution of 30 g of the solution containing (a-2) and a mixed solution of 3 g of 2,2'-azobis (2-methylpropionitrile) and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively, and this temperature was It was polymerized for 3 hours while maintaining. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-3). To obtain a solution. Mw of compound (A-3) was 8,280, Mn was 4,465, and Mw/Mn was 1.84.

[Synthesis Example 16] (Preparation of Compound (A-14))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Mixing of 30 g of a solution containing 100 g of methyl ethyl ketone, 51 g (0.49 mol) of styrene, 49 g (0.49 mol) of methyl methacrylate, and 10% by mass of a chain transfer agent (a-2) by heating to 85°C and at the same temperature The solution and a mixed solution of 4 g of Nichiyu's "perbutyl O" and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively, and polymerization was carried out for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-14). To obtain a solution. Mw of compound (A-14) was 7,750, Mn was 3,987, and Mw/Mn was 1.94.

[Synthesis Example 17] (Preparation of Compound (A-15))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heated to 85°C and at the same temperature, methyl ethyl ketone 100 g, styrene 48 g (0.46 mol), methyl methacrylate 46 g (0.46 mol), cyclohexyl methacrylate 6 g (0.036 mol), chain transfer agent (a-3) ("Conposeran HBSQ105-9" by Arakawa Chemical Co., Ltd., 25 mass% propylene glycol monomethyl ether acetate solution) 12 g of mixed solution and 2,2'-azobis(2-methylpropionitrile) 3 g A mixed solution of 100 g of methyl ethyl ketone was added dropwise over 3 hours, and polymerization was performed for 3 hours while maintaining this temperature. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-15). To obtain a solution. Mw of compound (A-15) was 7,980, Mn was 4,002, and Mw/Mn was 2.00.

[Synthesis Example 18] (Preparation of Compound (A-16))

Into a flask equipped with a cooling tube and a stirrer, 100 g of methyl ethyl ketone was added, followed by nitrogen substitution. Heat to 85°C, and at the same temperature, methyl ethyl ketone 100 g, styrene 51 g (0.49 mol), methyl methacrylate 49 g (0.49 mol), chain transfer agent (a-3) (Arakawa Chemical Co., Ltd. Column HBSQ105-9", 25 mass% propylene glycol monomethyl ether acetate solution) 12 g of a mixed solution and a mixed solution of 4 g of Nichiyu's "perbutyl O" and 100 g of methyl ethyl ketone were added dropwise over 3 hours, respectively, at this temperature It was polymerized for 3 hours while maintaining. The obtained compound solution was precipitated and purified with 3 L of methanol to remove residual monomers and radical polymerization initiators, and then this solution was diluted with propylene glycol monomethyl ether acetate to contain 10% by mass of compound (A-16). To obtain a solution. Mw of compound (A-16) was 7,807, Mn was 3,869, and Mw/Mn was 2.02.

[Synthesis Example 19] (Preparation of block copolymer (P-1))

After drying a 500 mL flask reaction vessel under reduced pressure, 200 g of tetrahydrofuran subjected to distillation dehydration treatment was poured under a nitrogen atmosphere and cooled to -78°C. Thereafter, 0.27 g of a 1N cyclohexane solution of sec-butyllithium (sec-BuLi) was injected, and 10.7 g (0.103 mol) of styrene subjected to distillation dehydration was added dropwise over 30 minutes. At this time, care was taken so that the temperature of the reaction solution was not higher than -60°C. After completion of the dropwise addition, after aging for 30 minutes, 10.3 g (0.103 mol) of methyl methacrylate further subjected to distillation and dehydration treatment was added dropwise over 30 minutes, followed by reaction for 120 minutes. Thereafter, 1 mL of methanol was injected as a terminal treatment agent and reacted. After the reaction solution was heated up to room temperature, the obtained reaction solution was concentrated and replaced with propylene glycol methyl ether acetate (PGMEA), 1,000 g of a 2 mass% oxalic acid aqueous solution was poured and stirred, and after standing, the lower layer aqueous layer was removed. After this operation was repeated 3 times to remove the Li salt, 1,000 g of ultrapure water was poured and stirred to remove the lower water layer. After this operation was repeated 3 times to remove oxalic acid, the solution was concentrated and dropped into 500 g of methanol to precipitate a polymer. The polymer filtered under reduced pressure was washed twice with methanol and then dried under reduced pressure at 60°C to obtain 20.5 g of a white block copolymer (P-1). Mw of the block copolymer (P-1) was 41,000 and Mw/Mn was 1.13. In addition, as ^{a result of 13} C-NMR analysis, the content ratio of the styrene unit and the content ratio of the methyl methacrylate unit in the block copolymer (P-1) were 50.1 (mol%) and 49.9 (mol%), respectively. In addition, the block copolymer (P-1) was a diblock copolymer.

<Preparation of the composition for forming an underlying film>

[B] Solvent and [C] acid generator constituting the composition for forming an underlying film other than the compounds (A-1) to (A-10) and (A-13) to (A-16) are as follows: Show.

[[B] solvent]

B-1: Propylene glycol monomethyl ether acetate

B-2: Butoxymethyl acetate

B-3: Butyl acetate

B-4: Cyclohexanone

[[C] acid generator]

C-1: Triphenylsulfonium 2-(bicyclo[2.2.1]hept-2-yl)-1,1,2,2-tetrafluoroethane-1-sulfonate

C-2: bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate

The structure of each compound is shown below.

[Example 1] (Preparation of a composition for forming a base film (D-1))

[A] 100 parts by mass of a solution containing the compound (A-1) obtained by Synthesis Example 1 as a solution containing the compound, [B] 9,895 parts by mass of propylene glycol monomethyl ether acetate as a solvent, and [B] C] (C-1) Triphenylsulfonium 2-(bicyclo[2.2.1]hept-2-yl)-1,1,2,2-tetrafluoroethane-1-sulfonate 5 as an acid generator The mass parts were mixed and dissolved to obtain a mixed solution. The obtained mixed solution was filtered through a membrane filter having a pore diameter of 0.1 µm to prepare a composition for forming an underlying film (D-1).

[Examples 2 to 15 and Comparative Examples 1 to 4] (Preparation of base film-forming compositions (D-2) to (D-19))

Compositions (D-2) to (D-19) for forming an underlying film of Examples 2 to 15 and Comparative Examples 1 to 4 in the same manner as in Example 1 except that each component of the type and content shown in Table 1 below was used. Was prepared. In addition, "-" in Table 1 shows that the corresponding component was not used.

<Self-Organizing Lithography Method>

A first substrate formed with a base film was formed using the obtained composition for forming a base film, and a pattern was formed using the first substrate formed with the base film.

(1) Preparation of self-organizing composition for pattern formation

The obtained block copolymer (P-1) was dissolved in propylene glycol monomethyl ether acetate (PGMEA) to obtain a 1% by mass solution. This solution was filtered through a membrane filter having a pore diameter of 200 nm to prepare a self-assembled composition for pattern formation (E-1).

(2) Formation of the underlying film of the first layer

Using the obtained base film-forming compositions (D-1) to (D-19), a coating film was formed on the surface of a 12-inch silicon wafer, exposed with ArF light having a wavelength of 193 nm, and fired at 200°C for 120 seconds. did. Subsequently, after washing with propylene glycol monomethyl ether acetate in order to remove the solution containing the unreacted polymer, the substrate was dried at 100° C. for 120 seconds to form a coating film having an average thickness of 10 nm.

[Measurement of retraction contact angle (RCA)]

The measurement of the retreat contact angle was performed using a contact angle meter (“DSA-10” from KRUS) to prepare a substrate (wafer) formed with an underlying film from the composition for forming an underlying film, and then quickly room temperature: 23°C, humidity: 45 %, it carried out by the following procedure in an environment of normal pressure.

First, the position of the wafer stage of the contact angle meter was adjusted, and the wafer was set on the adjusted stage. Next, water was injected into the needle, and the position of the needle was finely adjusted to an initial position where water droplets could be formed on the set wafer. Thereafter, water was discharged from the needle to form a water droplet of 25 µL on the wafer, and the needle was first pulled out from the water droplet, and the needle was lowered back to the initial position and placed in the water droplet. Subsequently, for 150 seconds at a rate of 10 μL/min, water droplets were aspirated with a needle, and the contact angle was measured 150 times once a second. Among them, the average value of the contact angle for 20 seconds (20 points in total) from the point when the measured value of the contact angle was stabilized was calculated, and it was set as the retreat contact angle (unit: degrees (°)). Table 2 shows the obtained values.

(3) formation of patterns

After applying the self-organizing composition (E-1) for pattern formation so that the average thickness of the self-assembled film formed on the silicon wafer substrate formed with the underlying film is 30 nm, it is heated at 250° C. for 10 minutes to perform phase separation. After forming a fingerprint having a domain structure, dry etching was performed by plasma treatment to form an uneven pattern having a pitch of 30 nm.

The cross-section of the formed fingerprint and pattern was observed using a scanning electron microscope (“S-4800” by Hitachi Seisakusho), and the goodness of the phase-separated structure in the fingerprint and the rectangularity of the pattern shape Evaluated. In the fingerprint, a clear phase separation could be confirmed, and the absence of defects was referred to as "A" (good), and the incomplete or defective phase separation was referred to as "B" (defective). The pattern shape was evaluated as "A" (good) when it was recognized as a rectangle, and evaluated as "B" (defective) when it was not recognized as a rectangle, such as remarkable dissolution residuals. Table 2 shows the evaluation results.

As apparent from the results of Table 2, in Examples, it can be seen that the retreat contact angle of the surface of the first substrate formed with the underlying film is in a good range, the phase separation structure of the fingerprint is good, and the pattern shape is rectangular. On the other hand, in the comparative example, it can be seen that the retreat contact angle of the surface of the first substrate formed with the underlying film is not in a good range, the phase separation structure of the fingerprint is not good, and the pattern shape is not rectangular.

<Industrial availability>

According to the composition for forming an underlying film and the self-assembly lithography method of the present invention, a phase-separated structure by self-assembly can be formed satisfactorily, and a rectangular pattern can be formed. Therefore, these can be suitably used for a lithography method in manufacturing various electronic devices such as semiconductor devices and liquid crystal devices that are required to be further refined.

101 substrate
102 Underlayer
103 Preliminary patterns
104 coating
105 Self-Organizing Membrane
105a One side of the self-organizing film
105b The other side of the self-organizing film

Claims (15)

A composition for forming a base film disposed between a layer containing a silicon atom and a self-organizing film in a self-organizing lithography method,
A compound having a group capable of reacting with Si-OH or Si-H, and
menstruum
Contains,
The retreat contact angle of the underlayer with pure water is 70° or more and 90° or less,
The compound is represented by the following formula (1), a composition for forming an underlying film.

(In formula (1), A is a (m+n) valent linking group, D is a monovalent organic group having 10 or more carbon atoms, and E is a group capable of reacting with Si-OH or Si-H, a hydroxy group, the following formula: The group represented by (2) and any one of an alkoxy group, m and n are each independently an integer of 1 to 200, provided that when m is 2 or more, a plurality of D may be the same or different, and 2 Two or more D may be bonded to each other, and if n is 2 or more, a plurality of E may be the same or different)

(In Formula (2), R ^A is a C 1 to C 20 monovalent hydrocarbon group, R ^B is a C 1 to C 20 monovalent oxyhydrocarbon group or a halogen atom, a is an integer of 0 to 2, provided that R ^{When A} and R ^B are each plural, plural R ^A may be the same or different, and plural R ^B may be the same or different) The composition for forming an underlying film according to claim 1, wherein D in the general formula (1) is a group containing a sulfur atom. The composition for forming an underlying film according to claim 2, wherein D and A in the general formula (1) are bonded via the sulfur atom. The composition for forming an underlying film according to claim 1, wherein A in the general formula (1) is an organic group having 1 to 30 carbon atoms, and n is an integer of 1 to 10. The composition for forming an underlying film according to claim 4, wherein the compound does not have a group containing active hydrogen other than the group represented by E in the formula (1). The composition for forming an underlying film according to claim 1, wherein A in the general formula (1) is a group represented by the following general formula (3).

(In Formula (3), Q is a polysiloxane structure having 2 to 100 silicon atoms of (m+n) valence, and T is a divalent organic group having 1 to 30 carbon atoms bonded at a silicon atom of Q and a carbon atom or an oxygen atom, , m and n are the same as those of the above formula (1), * ¹ represents a site bonded to E in ^{the above formula (1), * 2} represents a site bonded to D in the above formula (1) Indicates) The composition for forming an underlying film according to claim 1, wherein D in the general formula (1) is a group containing a polymerized chain containing a carbon-carbon bond. The composition for forming an underlying film according to claim 2, wherein the compound is radically polymerized with a vinyl monomer in the presence of a chain transfer agent represented by the following formula (4).

(In Formula (4), A, E, m and n are the same as in Formula (1)) The composition for forming an underlying film according to claim 1, further comprising an acid generator. The composition for forming an underlying film according to claim 1, wherein the solvent comprises an ester-based solvent, a ketone-based solvent, or a combination thereof. A step of forming a base film with a composition for forming a base film on the first layer containing a silicon atom,
Forming a self-assembled film on a surface of the base film opposite to the first layer, and
Step of removing at least a part of the image of the self-organizing film
And,
The self-assembling lithography method, wherein the composition for forming an underlying film is the composition for forming an underlying film according to claim 1. The method of claim 11, further comprising a step of forming a pre-pattern on a surface of the base layer opposite to the first layer between the base layer forming process and the self-assembled layer forming process,
In the self-assembled film forming process, the self-assembled film is formed in a non-laminated region of the preliminary pattern. delete delete delete

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