JP2016117865A - Block copolymer, self-organizing composition for forming pattern and pattern formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a block copolymer that can form a fine and excellent pattern, a self-organizing composition for forming a pattern, and a pattern formation method.SOLUTION: The present invention provides a block copolymer represented by formula (1) [X is a vinyl aromatic compound-derived polymer block; Y is a conjugated diene or diphenyl ethylene derivative-derived polymer block; and Z is formula (2)].SELECTED DRAWING: Figure 4

Description

  The present invention relates to a block copolymer, a self-assembling composition for pattern formation containing the block copolymer, and a pattern forming method using the self-assembling composition for pattern formation.

With the miniaturization of various electronic device structures such as semiconductor devices and liquid crystal devices, pattern miniaturization in the lithography process is required. Currently, for example, a fine pattern having a line width of about 30 nm can be formed using ArF excimer laser light, but a finer pattern has been demanded.
In response to the above requirements, several pattern forming methods using a phase separation structure by so-called self-assembly (DSA) that spontaneously forms an ordered pattern have been proposed. Self-organization refers to a phenomenon in which a structure or structure is spontaneously built without being caused solely by control from external factors. For example, a monomer compound having one property and a monomer having a different property from that A method for forming an ultrafine pattern by self-assembly using a block copolymer obtained by copolymerization with a compound is known (see Patent Document 1). According to this method, by annealing the composition containing the block copolymer, polymer structures having the same properties tend to gather together, so that a pattern can be formed in a self-aligning manner.

  However, the pattern obtained by the conventional pattern formation method by self-organization cannot be said to be sufficiently fine yet, and there is a large variation in the pattern size even in the pattern shape, and sufficient performance when used as a device. The current situation is that we cannot say that

JP 2008-149447 A

  The present invention has been made on the basis of the circumstances as described above, and the object thereof is a block copolymer capable of forming a sufficiently fine and good pattern, and pattern formation including such a block copolymer. It is intended to provide a self-assembling composition and a pattern forming method.

（式中、Ｘはビニル芳香族化合物に由来する構造単位からなる数平均分子量が１０００〜３０００００の重合体ブロックを表す。Ｙは共役ジエンに由来する構造単位からなる数平均分子量が５０〜３０００の重合体ブロックまたはジフェニルエチレン誘導体に由来する構造単位を表す。
Ｚは式（２）

（式中、Ｒ^１は水素原子または炭素数１〜６の鎖状アルキル基を表す。Ｒ^２は構造中にエーテル基、アミノ基、シリルオキシ基、イミド基、エステル基、カルボキシル基、水酸基のうちいずれか１つ以上を含む有機基を表す。）で示される構造単位からなる数平均分子量が１０００〜３０００００の重合体ブロックを表す。）
［２］Ｙが共役ジエンに由来する構造単位からなる数平均分子量が５０〜３０００の重合体ブロックである、［１］のブロック共重合体。
［３］アニオン重合法により単量体の付加重合反応を段階的に行うことにより得られ、かつ分子の集合体においてシリンドリカル構造またはラメラ構造から選択される少なくとも１つであるミクロ相分離構造を形成しうる、［１］または［２］のブロック共重合体。
［４］［１］〜［３］のブロック共重合体を含有するパターン形成用自己組織化組成物。
［５］［４］のパターン形成用自己組織化組成物を用い、基板上にミクロ相分離構造を有する自己組織化膜を形成する工程１；および
上記自己組織化膜の一部の相を除去する工程２；
を含むパターン形成方法。
［６］上記工程１の前に、基板上に下層膜を形成する工程および上記下層膜上にプレパターンを形成する工程からなる工程０；をさらに有し、
上記工程１において、自己組織化膜を上記プレパターンによって区切られた上記下層膜上の領域に形成する［５］のパターン形成方法。
［７］得られるパターンがラインアンドスペースパターンまたはホールパターンである、［５］または［６］のパターン形成方法。 The present invention relates to the following [1] to [7].
[1] A block copolymer represented by the following general formula (1).

(In the formula, X represents a polymer block having a number average molecular weight of 1000 to 300,000 composed of a structural unit derived from a vinyl aromatic compound. Y represents a number average molecular weight of 50 to 3000 composed of a structural unit derived from a conjugated diene. It represents a structural unit derived from a polymer block or a diphenylethylene derivative.
Z is the formula (2)

(In the formula, R ¹ represents a hydrogen atom or a chain alkyl group having 1 to 6 carbon atoms. R ² represents an ether group, amino group, silyloxy group, imide group, ester group, carboxyl group, or hydroxyl group in the structure. It represents an organic group containing any one or more.) Represents a polymer block having a number average molecular weight of 1000 to 300000 consisting of a structural unit represented by )
[2] The block copolymer according to [1], wherein Y is a polymer block having a number average molecular weight of 50 to 3000 and comprising a structural unit derived from a conjugated diene.
[3] A microphase-separated structure that is obtained by performing an addition polymerization reaction of monomers stepwise by an anionic polymerization method and that is at least one selected from a cylindrical structure or a lamellar structure in a molecular assembly A block copolymer of [1] or [2].
[4] A self-assembling composition for pattern formation containing the block copolymer of [1] to [3].
[5] Step 1 of forming a self-assembled film having a microphase separation structure on a substrate using the pattern-forming self-assembled composition of [4]; and removing a part of the phase of the self-assembled film Performing step 2;
A pattern forming method including:
[6] Before the step 1, the method further comprises a step 0 comprising a step of forming a lower layer film on the substrate and a step of forming a pre-pattern on the lower layer film,
[5] The pattern forming method according to [5], wherein in the step 1, a self-assembled film is formed in a region on the lower layer film delimited by the prepattern.
[7] The pattern forming method according to [5] or [6], wherein the obtained pattern is a line and space pattern or a hole pattern.

  ADVANTAGE OF THE INVENTION According to this invention, the block copolymer (1) which can form a sufficiently fine pattern, the self-organization composition for pattern formation, and the pattern formation method can be provided. The block copolymer (1), the self-assembling composition for pattern formation, and the pattern forming method of the present invention are suitably used for lithography processes in manufacturing various electronic devices such as semiconductor devices and liquid crystal devices.

It is the board | substrate 11 in the pattern formation method of this invention. In the pattern formation method of this invention, it is a schematic diagram which shows an example of the state after forming the lower layer film | membrane 12 on the board | substrate 11. FIG. In the pattern formation method of this invention, it is a schematic diagram which shows the state after forming the pre pattern 14 on the lower layer film 12. FIG. In the pattern formation method of the present invention, after applying the self-assembling composition for pattern formation of the present invention to the region on the lower layer film delimited by the pre-pattern 14 to form the self-assembled film (13; 13a + 13b) It is a schematic diagram which shows an example of the state of. In the pattern formation method of this invention, it is a schematic diagram which shows the state after removing the one part phase 13b of a self-organization film | membrane (13; 13a + 13b).

  Hereinafter, the present invention will be described in detail.

<< Block copolymer (1) >>
Since the block copolymer (1) of the present invention has the primary structure defined in the present invention, a self-assembling composition for pattern formation containing such a block copolymer (1) is formed on a substrate. By coating, a film having a phase separation structure by self-organization, preferably a microphase separation structure which is at least one selected from a cylindrical structure or a lamellar structure (self-assembled film) is formed. A pattern can be formed by removing a part of the phase in the chemical film.

（式中、Ｒ^１は水素原子あるいは炭素数１〜６の鎖状アルキル基を表す。Ｒ^２は構造中にエーテル基、アミノ基、シリルオキシ基、イミド基、エステル基、カルボキシル基、水酸基のうちいずれか１つ以上を含む有機基を表す。）で示される構造単位からなる重合体ブロックを表す。そして重合体ブロックＸおよび重合体ブロックＺの数平均分子量がそれぞれ１０００〜３０００００であり、Ｙが共役ジエンに由来する構造単位からなる重合体ブロックである場合には、その数平均分子量が５０〜３０００である。 The block copolymer (1) of the present invention contains three polymer blocks or structural units of X, Y and Z in the molecular main chain. Here, X represents a polymer block composed of a structural unit derived from a vinyl aromatic compound, Y represents a polymer block composed of a structural unit derived from a conjugated diene or a structural unit derived from a diphenylethylene derivative, and Z represents a formula (2)

(In the formula, R ¹ represents a hydrogen atom or a chain alkyl group having 1 to 6 carbon atoms. R ² represents an ether group, amino group, silyloxy group, imide group, ester group, carboxyl group, or hydroxyl group in the structure. It represents an organic group containing any one or more.) Represents a polymer block composed of a structural unit represented by When the polymer block X and the polymer block Z have a number average molecular weight of 1000 to 300,000 and Y is a polymer block composed of a structural unit derived from a conjugated diene, the number average molecular weight is 50 to 3000. It is.

Examples of the vinyl aromatic compound constituting the polymer block X include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-tert-butylstyrene, 2,4. -Styrenic compounds such as dimethylstyrene, 2,4,6-trimethylstyrene, p-trimethylsilylstyrene; Vinylnaphthalene-based compounds such as 1-vinylnaphthalene and 2-vinylnaphthalene; 2-vinylanthracene, 9-vinylanthracene, etc. And vinyl anthracene compounds. The polymer block X may be composed of one kind of these vinyl aromatic compounds, or may be composed of two or more kinds in combination.
Among them, the polymer block X is preferably composed of styrene, α-methylstyrene, p-tert-butylstyrene, p-trimethylsilylstyrene, styrene only, p-tert-butylstyrene only, or p-trimethylsilylstyrene. It is more preferable that it is comprised only by.
The number average molecular weight of the polymer block X is in the range of 1000 to 300,000, preferably 3000 to 270000, and more preferably 5000 to 250,000.

Examples of the conjugated diene constituting Y include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 1,3-cyclohexadiene, and the like. Y may be composed of one or more of these conjugated dienes, but is preferably composed of one kind alone.
When Y is a polymer block composed of a structural unit derived from a conjugated diene, the number average molecular weight is 50 to 3000, preferably 50 to 2000, and more preferably 50 to 1000. By setting the number average molecular weight within the above range, a sufficiently fine and satisfactory pattern can be formed.
Y may be a structural unit derived from a diphenylethylene derivative. In the present invention, the diphenylethylene derivative refers to a compound in which two of the hydrogen atoms of ethylene are substituted with a phenyl group. Examples of the diphenylethylene derivative include 1,1-diphenylethylene, trans-1,2-diphenylethylene, cis-1,2-diphenylethylene, and the like. Among these, 1,1-diphenylethylene is preferable.

In the structural unit represented by the formula (2) constituting the polymer block Z, as the organic group represented by R ² , examples of the organic group having an ether group in the structure include methoxyethyl group, diethylene glycol monomethyl ether group, triethylene Glycol monomethyl ether group, tetraethylene glycol monoethyl ether group, ethoxyethyl group, diethylene glycol monoethyl ether group, triethylene glycol monoethyl ether group, tetraethylene glycol monoethyl ether group, glycidyl group, tetrahydrofurfuryl group, tetrahydropyranyl Examples of organic groups having a silyloxy group in the structure include [tris (trimethylsiloxy) silyl] propyl group, (trimethoxysilyl) propyl group, and (triethoxysilyl) pro Pill group, trimethylsilyloxyethyl group, diethylene glycol 2-trimethylsilyl ether group, triethylene glycol 2-trimethylsilyl ether group, tetraethylene glycol 2-trimethylsilyl ether group, 2-triethylsilyloxyethyl group, diethylene glycol 2-triethylsilyl ether group, Triethylene glycol 2-triethylsilyl ether group, tetraethylene glycol 2-triethylsilyl ether group; organic groups having an amino group in the structure include, for example, (dimethylamino) ethyl group, (diethylamino) ethyl group, morpholinoethyl group, 2,2,6,6-tetramethyl-4-piperidyl group; as an organic group having an imide group in the structure, for example, an N-succinimidyl group; an organic group having an ester group in the structure As, for example, 2-tert-butoxy-2-oxoethyl group, 1-methyl-2-tert-butoxy-2-oxoethyl group, 1-ethyl-2-tert-butoxy-2-oxoethyl group, 1-methyl-3 -Tert-butoxy-3-oxopropyl group, 4-tert-butoxy-4-oxobutyl group; examples of the organic group having a carboxyl group in the structure include carboxymethyl group, carboxyethyl group, carboxypropyl group, carboxybutyl group An organic group having a hydroxyl group in the structure includes, for example, a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, and the like. Among these, an organic group having an ether group, an amino group, a silyloxy group, a carboxyl group, or a hydroxyl group is preferable.

In the structural unit represented by the formula (2) constituting the polymer block Z, R ¹ represents a hydrogen atom or a chain alkyl group having 1 to 6 carbon atoms. Among them, R ¹ is preferably a hydrogen atom or a methyl group, that is, a structural unit derived from an acrylate ester or a methacrylate ester. Hereinafter, the acrylic acid ester or methacrylic acid ester will be collectively referred to as a (meth) acrylic acid ester and will be described in detail.

  Examples of the (meth) acrylic acid ester constituting the polymer block Z include, for example, 2-methoxyethyl methacrylate, diethylene glycol monomethyl ether methacrylate, triethylene glycol monomethyl ether methacrylate, tetraethylene glycol monomethyl ether methacrylate, 2-methacrylic acid 2- Ethoxyethyl, methacrylate diethylene glycol monoethyl ether, methacrylate triethylene glycol monoethyl ether, methacrylate tetraethylene glycol monoethyl ether, methacrylate 3- [tris (trimethylsiloxy) silyl] propyl, methacrylate 3- (trimethoxysilyl) ) Propyl, 3- (triethoxysilyl) propyl methacrylate, 2- (dimethylamino) ethyl methacrylate, methacrylate 2- (diethylamino) ethyl acid, 2-morpholinoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, (2-tetrahydropyranyl) methyl methacrylate, 2,2,6,6-tetramethyl-4 methacrylate -Piperidyl, N-succinimidyl methacrylate, 2-tert-butoxy-2-oxoethyl methacrylate, 1-methyl-2-tert-butoxy-2-oxoethyl methacrylate, 1-ethyl-2-tert-butoxy-2 methacrylate -Oxoethyl, 1-methyl-3-tert-butoxy-3-oxopropyl methacrylate, 4-tert-butoxy-4-oxobutyl methacrylate, 2-trimethylsilyloxyethyl methacrylate, diethylene glycol 2-trimethyl methacrylate Ril ether, triethylene glycol 2-trimethylsilyl ether, tetraethylene glycol 2-trimethylsilyl methacrylate, 2-triethylsilyloxyethyl methacrylate, diethylene glycol 2-triethylsilyl ether, triethylene glycol 2-triethylsilyl ether , Methacrylic acid esters such as tetraethylene glycol 2-triethylsilyl ether methacrylate; 2-methoxyethyl acrylate, diethylene glycol monomethyl ether acrylate, triethylene glycol monomethyl ether acrylate, tetraethylene glycol monomethyl ether acrylate, acrylic acid 2- Ethoxyethyl, diethylene glycol acrylate monoethyl acetate Tellurium, triethylene glycol monoethyl ether acrylate, tetraethylene glycol monoethyl ether acrylate, 3- [tris (trimethylsiloxy) silyl] propyl acrylate, 3- (trimethoxysilyl) propyl acrylate, 3- (acrylic acid 3- ( Triethoxysilyl) propyl, 2- (dimethylamino) ethyl acrylate, 2- (diethylamino) ethyl acrylate, 2-morpholinoethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, acrylic acid (2-tetrahydropyranyl) ) Methyl, 2,2,6,6-tetramethyl-4-piperidyl acrylate, N-succinimidyl acrylate, 2-tert-butoxy-2-oxoethyl acrylate, 1-methyl-2-tert-butoxy-acrylate -Oxoethyl, 1-ethyl-2-tert-butoxy-2-oxoethyl acrylate, 1-methyl-3-tert-butoxy-3-oxopropyl acrylate, 4-tert-butoxy-4-oxobutyl acrylate, acrylic acid 2-trimethylsilyloxyethyl, diethylene glycol 2-trimethylsilyl ether, triethylene glycol 2-trimethylsilyl ether, tetraethylene glycol 2-trimethylsilyl ether, 2-triethylsilyloxyethyl acrylate, diethylene glycol 2-triethyl methacrylate Such as silyl ether, acrylic acid triethylene glycol 2-triethylsilyl ether, acrylic acid tetraethylene glycol 2-triethylsilyl ether, etc. Le acid esters.

  The (meth) acrylic acid ester constituting the polymer block Z is 2-tert-butoxy-2-oxoethyl methacrylate, 1-methyl-2-tert-butoxy-2-oxoethyl methacrylate, 1-ethyl-2 methacrylate -Tert-butoxy-2-oxoethyl, 1-methyl-3-tert-butoxy-3-oxopropyl methacrylate, 4-tert-butoxy-4-oxobutyl methacrylate, 2-tert-butoxy-2-oxoethyl acrylate, 1-methyl-2-tert-butoxy-2-oxoethyl acrylate, 1-ethyl-2-tert-butoxy-2-oxoethyl acrylate, 1-methyl-3-tert-butoxy-3-oxopropyl acrylate, acrylic In the case of the acid 4-tert-butoxy-4-oxobutyl , By deprotection by known methods such as by reacting with an acid after the formation of the block can be converted into polymer block Z having a carboxyl group.

The (meth) acrylic acid ester constituting the polymer block Z is 2-trimethylsilyloxymethacrylate, diethylene glycol 2-trimethylsilyl ether, triethylene glycol 2-trimethylsilyl ether, tetraethylene glycol 2-trimethylsilyl methacrylate Ether, 2-triethylsilyloxyethyl methacrylate, diethylene glycol 2-triethylsilyl ether methacrylate, triethylene glycol 2-triethylsilyl ether methacrylate, tetraethylene glycol 2-triethylsilyl ether methacrylate, 2-trimethylsilyloxyethyl acrylate , Diethylene glycol acrylate 2-trimethylsilyl ether, triethylene glycol acrylate 2- Limethylsilyl ether, tetraethylene glycol 2-trimethylsilyl ether, 2-triethylsilyloxyethyl acrylate, diethylene glycol 2-triethylsilyl ether, triethylene glycol 2-triethylsilyl ether, tetraethylene glycol acrylate 2 -In the case of triethylsilyl ether, it can be converted to a polymer block Z having a hydroxyl group by deprotection by a known method such as reaction with an acid, fluorine ion or the like after forming the block.
The polymer block Z may be comprised from 1 type of these (meth) acrylic acid ester, or may be comprised combining 2 or more types.
The number average molecular weight of the polymer block Z is 1000 to 300,000, preferably 3000 to 270000, and more preferably 5000 to 250,000.

The ratio (X: Z) of the number average molecular weight of the polymer block X and the polymer block Z is preferably in the range of 30:70 to 90:10. In particular, when the microphase separation structure of the self-assembled film is a cylindrical structure, it is more preferably in the range of 50:50 to 90:10, and when it is a lamellar structure, 30:70 to 70:30. It is more preferable that it is in the range.
The number average molecular weight of the block copolymer (1) of the present invention is preferably in the range of 5,000 to 500,000, and more preferably 10,000 to 300,000. The molecular weight distribution (weight average molecular weight / number average molecular weight) of the block copolymer (1) is preferably in the range of 1.0 to 1.5, more preferably 1.0 to 1.2. 1.0 to 1.15 is more preferable, and 1.0 to 1.11.
In addition, the number average molecular weight of a block copolymer (1) is the value computed in standard polystyrene conversion using the gel permeation chromatography (GPC) according to the Example mentioned later. The number average molecular weights of the polymer block X, the polymer block Y composed of structural units derived from the conjugated diene, and the polymer block Z are the spectra obtained by ¹ H-NMR according to the examples described later. The content of each structural unit in each block polymer is calculated from the integration ratio of the peaks corresponding to each structural unit in the above, and the value calculated from the GPC measurement result and the result of the content of each structural unit by ¹ H-NMR is there.

  The block copolymer (1) of the present invention is composed of the above-mentioned specific polymer block X, specific Y and specific polymer block Z, thereby forming a phase separation structure by self-assembly (DSA). It is easy to do. In particular, the self-assembling composition for pattern formation containing the block copolymer (1) of the present invention using such properties is preferably a microphase which is at least one selected from a cylindrical structure or a lamellar structure. A film having a separation structure (self-assembled film) can be formed, and a sufficiently fine and good pattern can be formed. Therefore, the pattern formation method using the self-assembling composition for pattern formation containing the block copolymer (1) of the present invention is suitably used for lithography processes in the production of various electronic devices such as semiconductor devices and liquid crystal devices. Can do.

The block copolymer (1) of the present invention is obtained by performing a polymerization reaction of a predetermined monomer stepwise according to a known anionic polymerization method, that is, a vinyl aromatic compound, a conjugated diene or a diphenylethylene derivative, a formula ( The anionic polymerization of the (meth) acrylic acid ester represented by 2) can be produced by performing stepwise in this order. The vinyl aromatic compound, conjugated diene or diphenylethylene derivative and (meth) acrylic acid ester to be used should be sufficiently dried in advance under an inert gas atmosphere such as nitrogen, argon or helium to facilitate the polymerization reaction. It is preferable from the point of proceeding. In the drying treatment, a dehydrating agent or a desiccant such as calcium hydride, molecular sieves or activated alumina is preferably used.
The anionic polymerization reaction conditions can be appropriately selected from the range of polymerization temperature −100 ° C. to + 100 ° C. and polymerization time 1 to 100 hours. The anionic polymerization is preferably performed in an atmosphere of an inert gas such as nitrogen, argon or helium.

As the polymerization initiator in the above anionic polymerization, known anionic polymerization initiators can be used, for example, alkali metals such as metallic sodium and metallic lithium; organolithium compounds, organosodium compounds, organopotassium compounds and organomagnesium compounds. Is mentioned.
Examples of the organic lithium compound include methyl lithium, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, isobutyl lithium, tert-butyl lithium, n-pentyl lithium, n-hexyl lithium, tetra Alkyllithium and alkyldilithium such as methylenedilithium, pentamethylenedilithium, hexamethylenedilithium; aryllithium and aryldilithium such as phenyllithium, m-tolyllithium, p-tolyllithium, xylyllithium, lithium naphthalene; Benzyl lithium, diphenylmethyl lithium, trityl lithium, 1,1-diphenyl-3-methylpentyl lithium, α-methylstyryl lithium, diisopropenyl base Aralkyllithium and aralkyldilithium such as dilithium produced by the reaction of zen and butyllithium; lithium amides such as lithium dimethylamide, lithium diethylamide and lithium diisopropylamide; lithium methoxide, lithium ethoxide, lithium n-propoxide, lithium isoform Lithium alkoxides such as propoxide, lithium n-butoxide, lithium sec-butoxide, lithium tert-butoxide, lithium pentyl oxide, lithium hexyl oxide, lithium heptyl oxide, lithium octyl oxide; lithium phenoxide, lithium 4-methylphenoxide, lithium benzyl oxide And lithium 4-methylbenzyl oxide.

  Examples of the organic sodium compound include methyl sodium, ethyl sodium, n-propyl sodium, isopropyl sodium, n-butyl sodium, sec-butyl sodium, isobutyl sodium, tert-butyl sodium, n-pentyl sodium, n-hexyl sodium, tetra Alkyl sodium and alkyl disodium such as methylene disodium, pentamethylene disodium, hexamethylene disodium; aryl sodium and aryl disodium such as phenyl sodium, m-tolyl sodium, p-tolyl sodium, xylyl sodium, sodium naphthalene; Benzyl sodium, diphenylmethyl sodium, trityl sodium, diisopropenylbenzene and butyl sodium Aralkyl sodium and aralkyl disodium such as disodium produced by reaction with sodium; sodium amide such as sodium dimethylamide, sodium diethylamide, sodium diisopropylamide; sodium methoxide, sodium ethoxide, sodium n-propoxide, sodium isopropoxy Sodium alkoxide such as sodium n-butoxide, sodium sec-butoxide, sodium tert-butoxide, sodium pentyl oxide, sodium hexyl oxide, sodium heptyl oxide, sodium octyl oxide; sodium phenoxide, sodium 4-methylphenoxide, sodium benzyl oxide, Examples include sodium 4-methylbenzyl oxide.

  Examples of the organic potassium compound include methyl potassium, ethyl potassium, n-propyl potassium, isopropyl potassium, n-butyl potassium, sec-butyl potassium, isobutyl potassium, tert-butyl potassium, n-pentyl potassium, n-hexyl potassium, tetra Alkyl potassium and alkyl dipotassium such as methylene dipotassium, pentamethylene dipotassium, hexamethylene dipotassium; aryl potassium and aryl dipotassium such as phenyl potassium, m-tolyl potassium, p-tolyl potassium, xylyl potassium, potassium naphthalene; benzyl potassium, diphenylmethyl Aralkyl carbonates such as dipotassium produced by reaction with potassium, trityl potassium, diisopropenylbenzene and butyl potassium Potassium and aralkyl dipotassium; potassium amides such as potassium dimethylamide, potassium diethylamide, potassium diisopropylamide; potassium methoxide, potassium ethoxide, potassium n-propoxide, potassium isopropoxide, potassium n-butoxide, potassium sec-butoxide, potassium Examples include potassium alkoxides such as tert-butoxide, potassium pentyl oxide, potassium hexyl oxide, potassium heptyl oxide, and potassium octyl oxide; potassium phenoxide, potassium 4-methylphenoxide, potassium benzyl oxide, potassium 4-methylbenzyl oxide, and the like.

  Examples of the organic magnesium compound include dimethyl magnesium, diethyl magnesium, dibutyl magnesium, ethyl butyl magnesium, methyl magnesium bromide, ethyl magnesium chloride, ethyl magnesium bromide, phenyl magnesium chloride, phenyl magnesium bromide, tert-butyl magnesium chloride, tert-butyl magnesium. Examples include bromide.

Among these polymerization initiators, an organic lithium compound is preferable from the viewpoint of safety, handleability, high polymerization initiation efficiency, and smooth anion polymerization reaction. Among them, n-butyllithium, sec-butyllithium, tert-butyl are preferable. Particularly preferred are lithium, diphenylmethyllithium, 1,1-diphenyl-3-methylpentyllithium, and α-methylstyryllithium. As the polymerization initiator, one of the above polymerization initiators may be used alone, or two or more thereof may be used in combination.
The amount of the polymerization initiator used is not particularly limited, but it is usually intended that the concentration in the polymerization reaction solution is in the range of 0.1 to 100 mmol / l, preferably in the range of 1 to 10 mmol / l. It is preferable from the point which can manufacture a block copolymer (1) smoothly.

The anionic polymerization is preferably performed in the presence of a solvent. The solvent to be used is not particularly limited as long as it does not adversely affect the anionic polymerization reaction. For example, aliphatic hydrocarbons such as pentane, n-hexane, and octane; cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, etc. And alicyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene; and ethers such as diethyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, anisole and diphenyl ether. Among these, cyclohexane, toluene, and xylene are preferably used from the viewpoints of high solubility of the generated block copolymer (1), difficulty in mixing with waste water, and easy recovery and purification of the solvent. These solvents may be used alone or in combination of two or more. In addition, it is preferable from the point which advances the anionic polymerization reaction that the solvent to be used refine | purifies previously by deaerating and dehydrating.
Although there is no restriction | limiting in particular in the usage-amount of a solvent, Usually, 1-100 mass parts is preferable with respect to 1 mass part of total amounts of the monomer used for anionic polymerization.

In the above anionic polymerization, when the polymer block Z is formed, that is, when the above-mentioned (meth) acrylic acid ester is polymerized, the viewpoint of making the polymerization conditions more gentle and the viewpoint of polymerization results (living property, block efficiency, etc.) To an organoaluminum compound, preferably an anionic polymerization reaction in the presence of a tertiary organoaluminum compound having a chemical structure represented by the formula Al-O-Ar (wherein Ar represents an aromatic ring) in the molecule. It is extremely preferable (see, for example, JP-A-2001-158805).
As the tertiary organoaluminum compound having a chemical structure represented by the above formula Al-O-Ar (wherein Ar represents an aromatic ring) in the molecule, for example, ethyl bis (2,6-ditert-butyl-4- Methylphenoxy) aluminum, ethylbis (2,6-ditert-butylphenoxy) aluminum, ethyl [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, isobutylbis (2,6-di) tert-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6-ditert-butylphenoxy) aluminum, isobutyl [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, n -Octylbis (2,6-ditert-butyl-4-methylphenoxy) Luminium, n-octylbis (2,6-ditert-butylphenoxy) aluminum, n-octyl [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, methoxybis (2,6-di) tert-butyl-4-methylphenoxy) aluminum, methoxybis (2,6-ditert-butylphenoxy) aluminum, methoxy [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, ethoxybis ( 2,6-ditert-butyl-4-methylphenoxy) aluminum, ethoxybis (2,6-ditert-butylphenoxy) aluminum, ethoxy [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy) ] Aluminum, isopropoxy Bis (2,6-ditert-butyl-4-methylphenoxy) aluminum, isopropoxybis (2,6-ditert-butylphenoxy) aluminum, isopropoxy [2,2′-methylenebis (4-methyl-6- tert-butylphenoxy)] aluminum, tert-butoxybis (2,6-ditert-butyl-4-methylphenoxy) aluminum, tert-butoxybis (2,6-ditert-butylphenoxy) aluminum, tert-butoxy [2, 2'-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum, tris (2,6-ditert-butyl-4-methylphenoxy) aluminum, tris (2,6-diphenylphenoxy) aluminum and the like. It is done. Among them, isobutylbis (2,6-ditert-butyl-4-methylphenoxy) aluminum, isobutylbis (2,6-ditert-butylphenoxy) aluminum, isobutyl [2,2′-methylenebis (4-methyl-6) -Tert-Butylphenoxy)] aluminum is particularly preferred from the viewpoints of high living property, availability, ease of handling, and the like. These may be used alone or in combination of two or more.

  The amount of the organoaluminum compound used can be appropriately selected in accordance with the type of solvent used when the polymer block Z is formed by anionic polymerization and various polymerization conditions. Usually, it is preferable to use an organoaluminum compound in an equimolar ratio or more with respect to an alkali metal atom (or anion center) such as lithium, sodium or potassium in the polymerization initiator to be used. It is more preferable to use in the ratio.

  When the anionic polymerization reaction is carried out by further coexisting the organoaluminum compound when forming the polymer block Z, the block efficiency and the polymerization rate in the anionic polymerization of (meth) acrylic acid ester are further improved, and the deactivation is suppressed. From the viewpoint of further improving the living property, an ether compound in the system; a tertiary polyamine; an inorganic salt such as lithium chloride; a metal alkoxide compound such as lithium methoxyethoxy ethoxide and potassium t-butoxide, as long as the polymerization reaction is not adversely affected An additive such as an organic quaternary salt such as tetraethylammonium chloride or tetraethylphosphonium bromide may coexist, and an ether compound or a tertiary polyamine compound is particularly preferably coexistent.

  The ether compound can be appropriately selected from compounds having an ether bond (—O—) in the molecule and containing no metal component, such as 12-crown-4, 15-crown-5, 18-crown. Cyclic ethers having two or more ether bonds in the molecule, such as crown ethers such as -6; acyclic monoethers such as dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, anisole; 1,2-dimethoxyethane, 1 , 2-diethoxyethane, 1,2-diisopropoxyethane, 1,2-dibutoxyethane, 1,2-diphenoxyethane, 1,2-dimethoxypropane, 1,2-diethoxypropane, 1,2 -Diisopropoxypropane, 1,2-dibutoxypropane, 1,2-diphenoxypropane, 1,3 Dimethoxypropane, 1,3-diethoxypropane, 1,3-diisopropoxypropane, 1,3-dibutoxypropane, 1,3-diphenoxypropane, 1,4-dimethoxybutane, 1,4-diethoxybutane Acyclic diether such as 1,4-diisopropoxybutane, 1,4-dibutoxybutane, 1,4-diphenoxybutane; diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dibutylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene Acyclic triethers such as glycol diethyl ether and dibutylene glycol diethyl ether; triethylene glycol dimethyl ether, tripropylene glycol dimethyl ether, tributylene glycol dimethyl ether Ether, triethylene glycol diethyl ether, tripropylene glycol diethyl ether, tributylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetrapropylene glycol dimethyl ether, tetrabutylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetrapropylene glycol diethyl ether, tetrabutylene glycol And acyclic ethers having one or more ether bonds in the molecule, such as dialkyl ethers of polyalkylene glycols such as diethyl ether. Among them, acyclic ether is preferable, and diethyl ether and 1,2-dimethoxyethane are more preferable.

  The tertiary polyamine compound can be appropriately selected from compounds having two or more tertiary amine structures in the molecule. In this specification, “tertiary amine structure” means a partial chemical structure in which three carbon atoms are bonded to one nitrogen atom, and the nitrogen atom is bonded to three carbon atoms. As long as it is, it may constitute a part of the aromatic ring. Examples of tertiary polyamine compounds include N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyl. Linear polyamines such as diethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetraamine, tris [2- (dimethylamino) ethyl] amine; 1,3,5-trimethylhexahydro-1, 3,5-triazine, 1,4,7-trimethyl-1,4,7-triazacyclononane, 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16 A non-aromatic heterocyclic compound such as hexaazacyclooctadecane; an aromatic heterocyclic compound such as 2,2′-bipyridyl, 2,2 ′: 6 ′, 2 ″ -terpyridine; Etc., and the like.

  When the above ether compound or tertiary polyamine compound is allowed to coexist, the amount is not particularly limited, but the total number of moles of the ether compound and tertiary polyamine compound is such as lithium, sodium, potassium, etc. in the polymerization initiator used. It is usually preferably 0.1 times or more, more preferably 0.3 times or more, and further preferably 0.5 times or more with respect to the number of moles of alkali metal atoms (or anion centers). . Moreover, it is preferable that the total amount of an ether compound and a tertiary polyamine compound is about 80 mass% or less with respect to a polymerization system.

After the above-mentioned anionic polymerization reaction, for example, methanol, acetic acid, hydrochloric acid in methanol or the like as a polymerization terminator, usually, preferably an alkali metal atom (or anion center) such as lithium, sodium or potassium in the polymerization initiator used. The polymerization reaction is stopped by adding to the reaction mixture in the range of 1 to 100 moles.
The method of isolating the block copolymer (1) of the present invention from such a reaction mixture includes, for example, a method of pouring the reaction mixture into a poor solvent of the block copolymer (1) and precipitating, and a solvent from the reaction mixture. Examples thereof include a method of distilling off to obtain the block copolymer (1).

  Here, the block copolymer (1) of the present invention isolated from the reaction mixture after termination of the polymerization is used with a metal component (typically lithium, sodium, potassium derived from the polymerization initiator or organoaluminum compound used). In the self-assembling composition for pattern formation of the present invention containing the block copolymer (1), the self-assembling ability tends to be adversely affected. From the viewpoint of maximizing the purpose of the above, it is preferable to remove the metal component derived from the polymerization initiator and the organoaluminum catalyst from the block copolymer (1) as much as possible. As a method for removing the metal component from the block copolymer (1), for example, the block copolymer (1) is prepared by using hydrochloric acid, sulfuric acid aqueous solution, nitric acid aqueous solution, acetic acid aqueous solution, propionic acid aqueous solution, citric acid aqueous solution, tartaric acid aqueous solution, or the like. A method of washing with an acidic aqueous solution, or the block copolymer (1) is dissolved in a solvent such as cyclohexane, toluene, xylene or the like in which the block copolymer (1) can be dissolved to form a solution state. And a method of removing the block copolymer (1) by contacting it with an appropriate adsorbent that is insoluble in a solvent capable of dissolving the block copolymer (1) and capable of adsorbing a metal component. .

<< Self-organized composition for pattern formation >>
The self-assembling composition for pattern formation of the present invention is characterized by containing a block copolymer (1). Moreover, you may further contain in the range with which the objective of this invention is achieved by using a solvent, another polymer, surfactant, etc. as an arbitrary component. In particular, when the self-assembling composition for pattern formation contains a surfactant, it is possible to improve applicability to a substrate or the like.
Examples of the solvent include diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, 1,4-dioxane and the like; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol mono Hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethyl Glycol ethers such as polyglycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether; Ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, nonyl acetate, ethyl propionate, propion Butyl acid, amyl propionate, methyl lactate, ethyl lactate, lactate Amyl lactate, methyl 3-methoxypropionate, methyl acetoacetate, ethyl acetoacetate, diethyl oxalate, dibutyl oxalate, diethyl malonate, dimethyl phthalate, diethyl phthalate, γ-butyrolactone, γ-valerolactone, diethyl Esters such as carbonate and propylene carbonate; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether propionate , Propylene glycol monomethyl ether acetate , Glycol ether esters such as propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate; acetone, methyl ethyl ketone, methyl-n-propyl Ketone, methyl isopropyl ketone, methyl n-butyl ketone, methyl isobutyl ketone, methyl amyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, diisobutyl ketone, trimethylnonanone, cyclopentanone, cyclohexanone, cycloheptanone, Cyclooctanone, methylcyclohexanone, 2,4-pentanedione, acetoni Ketones such as luacetone and acetophenone; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, cumene, diethylbenzene, isobutylbenzene, trimethylbenzene, diisopropylbenzene, and n-amylnaphthalene; It is done. These solvents may be used alone or in combination of two or more.
When mix | blending a solvent, it is preferable that the quantity is 1-50 mass parts normally with respect to 1 mass part of block copolymers (1), and it is preferable that it is 2-25 mass parts.

  Other polymers include, for example, polystyrene polymers, poly (meth) acrylic polymers, polyvinyl acetal polymers, polyurethane polymers, polyurea polymers, polyamides other than the block copolymer (1). Examples thereof include a polymer, a polyimide polymer, a polyester polymer, and an epoxy resin. These may be homopolymers synthesized from one type of monomer or copolymers synthesized from multiple types of monomers.

<< Pattern Forming Method >>
The pattern forming method of the present invention includes a step 1 of forming a self-assembled film having a phase separation structure on a substrate using the self-assembled composition for pattern formation of the present invention, and a part of the self-assembled film. Step 2 of removing the phase.
Further, before step 1, the method includes a step of forming a lower layer film on the substrate and a step 0 of forming a pre-pattern on the lower layer film, and the self-assembled film is separated by the pre-pattern in step 1 It is preferable to form in the region on the lower layer film. If necessary, in step 2, it is preferable to remove the prepattern in addition to a part of the phase of the self-assembled film.
Furthermore, it is preferable to further include a step 3 of etching the substrate after the step 2 using the formed pattern as a mask. Hereinafter, each step will be described.

<Process 0>
Step 0 is a step of forming the lower layer film 12 on the substrate 11 using the lower layer film forming composition and forming the prepattern 14 on the lower layer film 12 using the prepattern forming composition. . Thereby, a substrate with a lower layer film in which the lower layer film 12 is formed on the substrate 11 can be obtained, and the self-assembled film 13 is formed on the lower layer film 12. The phase separation structure (microphase separation structure which is at least one selected from a cylindrical structure or a lamellar structure) included in the self-assembled film 13 is a block copolymer (1 In addition to the interaction between the blocks), it also changes due to the interaction with the lower layer film 12, so that the lower layer film 12 makes it easy to control the structure and obtain a desired pattern. Moreover, the pattern shape obtained by the phase separation of the self-assembling composition for pattern formation is controlled by the pre-pattern 14, and a desired fine pattern can be formed. Further, when the self-assembled film is a thin film, the transfer process can be improved by having the lower layer film 12.
That is, among the polymer blocks contained in the block copolymer (1) contained in the self-assembling composition for pattern formation of the present invention, the polymer block having a high affinity with the prepattern side faces the phase along the prepattern. The polymer block that forms and has a low affinity forms a phase at a position away from the pre-pattern. Thereby, a desired pattern can be formed. Moreover, the structure of the pattern obtained by phase separation of the self-assembling composition for pattern formation can be finely controlled by the material, size, shape, etc. of the prepattern. The pre-pattern can be appropriately selected according to the pattern to be finally formed. For example, a line and space pattern, a hole pattern, or the like can be used.

  Examples of the substrate 11 include a silicon wafer; a metal substrate such as copper, chromium, iron, and aluminum; a substrate made of a metal oxide such as a glass substrate; and a polymer film (polyethylene, polyethylene terephthalate, polyimide, etc.). It is done. Moreover, the magnitude | size and shape of the board | substrate 11 are not specifically limited, Except being on a flat plate, it can select suitably.

  The substrate 11 may be cleaned in advance before forming the lower layer film 12, or may be provided with an antireflection film. By cleaning the surface of the substrate 11, the lower layer film 12 may be formed satisfactorily. A known method can be used as the cleaning treatment, and examples thereof include oxygen plasma treatment, ozone oxidation treatment, acid-alkali treatment, and chemical modification treatment. Typically, the step can be performed by immersing the substrate 11 in an acid solution such as a sulfuric acid / hydrogen peroxide aqueous solution, followed by washing with water and drying.

As the underlayer film forming composition, a composition comprising a resin composition can be used. Such a resin composition can be appropriately selected from conventionally known resin compositions used for thin film formation depending on the type of polymer block constituting the block copolymer (1). Alternatively, a photosensitive resin composition such as a positive resist composition or a negative resist composition may be used. In addition, the lower layer film may be a non-polymerized film such as a siloxane-based organic monomolecular film such as phenethyltrichlorosilane, octadecyltrichlorosilane, or hexamethyldisilazane. Especially, what consists of a resin composition etc. which all contain a structural unit with high affinity with each polymer block which comprises a block copolymer (1) is preferable.
For example, when the block copolymer (1) is a block copolymer in which the polymer block X is composed of structural units derived from styrene and the polymer block Z is composed of structural units derived from 2-methoxyethyl methacrylate. As a lower layer film, a resin composition containing both styrene and 2-methoxyethyl methacrylate as a monomer, a site having high affinity with an aromatic ring of styrene, and a polarity of 2-methoxyethyl methacrylate It is preferable to use a compound or composition containing both a functional group and a site with high affinity. Examples of the resin composition containing both styrene and 2-methoxyethyl methacrylate as monomers include, for example, a random copolymer of styrene and 2-methoxyethyl methacrylate, and an alternating copolymer of styrene and 2-methoxyethyl methacrylate. Etc. Examples of the compound containing both a portion having high affinity with the aromatic ring of styrene and a portion having high affinity with the polar functional group of 2-methoxyethyl methacrylate include a random copolymer of styrene and methyl methacrylate. And an alternating copolymer of styrene and methyl methacrylate.

  The formation method of the lower layer film 12 is not particularly limited. For example, a coating film formed by applying a known method such as a spin coating method on the substrate 11 is cured by exposure and / or heating. can do. Examples of the radiation used for this exposure include visible light, ultraviolet light, far ultraviolet light, X-rays, electron beams, γ-rays, molecular beams, and ion beams. Moreover, although the temperature at the time of heating a coating film is not specifically limited, Usually, it is preferable that it is 90-550 degreeC, 90-450 degreeC is more preferable, and 90 degreeC-300 degreeC is further more preferable. In addition, although the film thickness of the said lower layer film 12 is not specifically limited, Usually, 1 nm-5000 nm are preferable and 1 nm-1000 nm are more preferable.

As a method for forming the pre-pattern 14, a method similar to a known resist pattern forming method can be used. In addition, as the pre-pattern forming composition, a conventional resist film-forming composition can be used. As a specific method for forming the pre-pattern 14, for example, a commercially available chemically amplified resist is used and applied onto the lower layer film 12 to form a resist film. Next, exposure is performed by irradiating a desired region of the resist film with radiation through a mask having a specific pattern. Examples of the radiation include ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays, X-rays, and charged particle beams. Among these, far ultraviolet light and extreme ultraviolet (EUV) light represented by ArF excimer laser light and KrF excimer laser light are preferable. Moreover, immersion exposure can also be performed as an exposure method. Next, post-exposure baking (PEB) is performed, and development is performed using a developer such as an alkali developer or an organic solvent, whereby a desired prepattern 14 can be formed.
The surface of the pre-pattern 14 may be subjected to a hydrophobic treatment or a hydrophilic treatment. As a specific treatment method, there is a hydrogenation treatment in which the plasma is exposed to hydrogen plasma for a certain time. By increasing the hydrophobicity or hydrophilicity of the surface of the pre-pattern 14, the self-assembly of the pattern-forming self-assembly composition can be promoted.

<Step 1>
Step 1 is a step of forming a self-assembled film having a phase separation structure on a substrate using the self-assembled composition for pattern formation of the present invention. When the lower layer film and the prepattern are not used, the self-assembled composition for pattern formation is directly applied onto the substrate to form a coating film, thereby forming a self-assembled film having a phase separation structure. In the case of using the lower layer film and the pre-pattern, the lower layer film formed on the substrate 11 by applying the pattern-forming self-assembling composition to a region on the lower layer film 12 sandwiched by the pre-pattern 14. In this step, a self-assembled film 13 having a phase separation structure having an interface substantially perpendicular to the substrate 11 is formed on the substrate 12.
That is, the same property is obtained by applying a self-assembling composition for pattern formation containing a block copolymer (1) having two or more kinds of polymer blocks incompatible with each other on a substrate and performing annealing or the like. It is possible to promote so-called self-organization in which blocks having slabs accumulate to form an ordered pattern spontaneously. When the self-assembling composition for pattern formation of the present invention is used, a self-assembled film having a microphase separation structure that is at least one selected from a cylindrical structure or a lamellar structure can be formed. The separation structure is preferably a phase separation structure having an interface substantially perpendicular to the substrate 11. In the block copolymer (1) of the present invention that forms such a microphase-separated structure, the polymer block X and the polymer block Z are incompatible with each other as described above. A phase separation structure composed of a phase and a polymer block Z, and the molecular weight of Y is smaller than that of the polymer block X and the polymer block Z. It is presumed to exist mainly at the interface between the phase consisting of the polymer block and the phase consisting of the polymer block Z.
In this step, by using the self-assembling composition for pattern formation, phase separation is likely to occur, so that a finer microphase separation structure can be formed.

In the case of having a pre-pattern, the phase separation structure formed by promoting the self-assembly described above is preferably formed along the pre-pattern, and the interface formed by the phase separation is substantially the same as the side surface of the pre-pattern. More preferably, they are parallel. For example, when the pre-pattern is linear, when the affinity of the pre-pattern 14 and the styrene block of the block copolymer (1) is high, the phase of the polymer block X, typically a polystyrene block, is the pre-pattern. Formed linearly along line 14 (13a), next to polymer block Z via Y, typically a phase of polymethoxymethacrylate 2-methoxyethyl block (13b) and a phase of polystyrene block (13a) Form a lamellar phase separation structure alternately arranged in this order. When the prepattern is a hole pattern, a polystyrene block phase is formed along the hole side surface of the prepattern, and a polymethoxymethacrylate 2-methoxyethyl block phase is formed at the center of the hole. A cylindrical phase separation structure is formed.
The phase separation structure formed in this step is composed of a plurality of phases, and the interface formed from these phases is usually substantially vertical, but the interface itself is not necessarily clear. Further, the number average molecular weight of each polymer block constituting the block copolymer (1) of the present invention, the number average molecular weight of the block copolymer (1), the kind of composition constituting the prepattern, and the shape of the prepattern Depending on the type of composition for forming the lower layer film, the desired phase separation structure can be precisely controlled to obtain a desired fine pattern.

  The method for applying the self-assembling composition for pattern formation onto the substrate is not particularly limited, and examples thereof include a method of applying the coating composition by a spin coating method, etc. It is applied between the patterns 14 to form a self-assembled film.

  Examples of the annealing method include a method of heating at a temperature of 80 ° C. to 400 ° C. using an oven, a hot plate, or the like. The annealing time is usually 1 minute to 120 minutes, preferably 1 minute to 90 minutes. The film thickness of the resulting self-assembled film 13 is usually preferably 0.1 nm to 500 nm, and more preferably 0.5 nm to 100 nm.

<Step 2>
Step 2 is a step of removing a part of the block phase and / or pre-pattern in the phase separation structure of the self-assembled film 13. The removal of the pre-pattern may be performed simultaneously with the removal of a part of the block phase of the phase separation structure of the self-assembled film 13, or a part of the block of the phase separation structure of the self-assembled film 13 It may be done before or after removal of the phase.
When the block copolymer (1) is a block copolymer in which the polymer block X is a polystyrene block and the polymer block Z via Y is a poly (2-methoxyethyl methacrylate) block, self-assembly By using the difference in etching rate of the phases separated by the step, the polymethoxy 2-methoxyethyl methacrylate block phase 13b and / or the pre-pattern can be removed by the etching process. FIG. 5 shows a state after the polymethoxymethacrylate 2-methoxyethyl block phase 13b in the phase separation structure is removed (the pre-pattern 14 is left). In addition, you may irradiate a radiation before this etching process as needed. As such radiation, when the phase to be removed by etching is a polymethoxy 2-methoxyethyl polymer block phase, radiation of 254 nm can be used. Since the polymethoxy-2-methacrylic acid block phase is decomposed by the radiation irradiation, it is more easily etched.

As a method for removing the polymethoxy 2-methacrylic acid block phase 13b in the phase separation structure of the self-assembled film 13, for example, reactive ion etching (RIE) such as chemical dry etching or chemical wet etching; Known methods such as physical etching such as etching and ion beam etching may be used. Of these, reactive ion etching (RIE) is preferable. Among them, chemical dry etching using CF ₄ , O ₂ gas, etc., and chemical wet etching (wet development) using a liquid etching solution such as an organic solvent or hydrofluoric acid are preferable. More preferred. Examples of such organic solvents include alkanes such as n-pentane, n-hexane, and n-heptane; cycloalkanes such as cyclohexane, cycloheptane, and cyclooctane; ethyl acetate, n-butyl acetate, i-butyl acetate, and methyl propionate. Saturated carboxylic acid esters of; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone, 2-heptanone; alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 4-methyl-2-pentanol Etc. In addition, these may be used individually by 1 type, or may use 2 or more types together.

<Step 3>
Step 3 is a step of patterning after Step 2, for example, as block copolymer (1), polymer block X is a polystyrene block, and polymer block Z via Y is a polymethoxymethacrylate 2-methoxyethyl block. In the case where the block copolymer is used, the patterning is performed by etching the lower layer film and the substrate using the pattern made of the polystyrene block phase 13a which is a part of the block phase of the remaining phase separation film as a mask. After the patterning on the substrate is completed, the phase used as a mask is removed from the substrate by dissolution treatment or the like, and a finally patterned substrate (pattern) can be obtained. As the etching method, the same method as in step 2 can be used, and the etching gas and the etching solution can be appropriately selected depending on the material of the lower layer film and the substrate. For example, when the substrate is made of a silicon material, a mixed gas of chlorofluorocarbon gas and SF ₄ can be used. When the substrate is a metal film, a mixed gas of BCl ₃ and Cl ₂ can be used. Note that the pattern obtained by the pattern forming method is suitably used for a semiconductor element and the like, and the semiconductor element is widely used for an LED, a solar cell, and the like.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention concretely, this invention is not restrict | limited at all by these Examples.

<Weight average molecular weight (Mw) and number average molecular weight (Mn)>
The Mw and Mn of the block polymers obtained in each Example and Comparative Example were measured by gel permeation chromatography (GPC) using Tosoh GPC columns (TSKgel SuperMultipore HZ-M 3), and the following conditions It was measured by.
Eluent: Tetrahydrofuran Flow rate: 0.35 ml / min Sample concentration: 0.1% by mass
Column temperature: 40 ° C
Detector: UV detector (measurement wavelength: 254 nm)
Standard material: monodisperse polystyrene

^<1 H-NMR analysis>
¹ H-NMR analysis was performed using Bruker AV400 and deuterated chloroform as a measurement solvent. The content ratio of each structural unit in each block polymer is calculated from the integral ratio of the peaks corresponding to each structural unit in the spectrum obtained by ¹ H-NMR, and the result of the GPC measurement and each structural unit by ¹ H-NMR are calculated. The number average molecular weight of each polymer block was calculated from the result of the content rate.

<Example 1>
The inside of a 1 L four-neck flask equipped with a stirrer and a thermometer was purged with nitrogen, 105 g of cyclohexane, 0.80 g of a cyclohexane solution of sec-butyllithium (corresponding to sec-butyllithium 1.31 mmol), and styrene 26.2 g (251.8 mmol) (hereinafter abbreviated as St) was added and stirred at 25 ° C. for 4 hours. Next, while stirring this solution, 7.2 g of a cyclohexane solution containing 0.7 g (13.1 mmol) of butadiene (hereinafter abbreviated as Bd) was added and stirred at 25 ° C. for 1 hour. Subsequently, 105 g of toluene, 39.5 g of a toluene solution containing 19.7 mmol of isobutylbis (2,6-ditert-butyl-4-methylphenoxy) aluminum, and 10.5 g of 1,2-dimethoxyethane were separately mixed. The solution prepared above was added at 25 ° C. and cooled to 5 ° C., 26.2 g (181.7 mmol) of 2-methoxyethyl methacrylate (hereinafter abbreviated as M1) was added, and the mixture was stirred at 5 ° C. for 5 hours. After adding 3.0 g (93.8 mmol) of methanol to stop the polymerization, 300 g of toluene and 300 g of 5% acetic acid aqueous solution were added to the reaction mixture, and the mixture was stirred at 80 ° C. for 1 hour, and then left at 80 ° C. to stand for water. The layers were separated. The same washing operation was further performed 4 times using 300 g of 5% aqueous acetic acid solution, and then 300 g of distilled water was added and the mixture was stirred at 25 ° C. for 30 minutes and then allowed to stand at 25 ° C. to separate the aqueous layer. I went twice. The obtained organic layer was dropped into 4000 g of methanol at 25 ° C. over 1 hour, and the precipitated solid was separated by filtration and dried under reduced pressure at 60 ° C. to obtain a block copolymer (A1) [polystyrene-polybutadiene-poly (methacrylic acid). 20.9 g of a triblock copolymer of 2-methoxyethyl).
From GPC and ¹ H-NMR analysis, Mn = 42010 of block copolymer (A1), Mw / Mn = 1.03, Mn = 20800 of polystyrene block (hereinafter abbreviated as PSt block), polybutadiene block (hereinafter, Mn = 410 of the PBd block) and Mn = 20800 of the poly (2-methoxyethyl methacrylate) block (hereinafter abbreviated as PM1 block).

<Examples 2 to 10>
In Example 1, 26.2 g (140.0 mmol) of diethylene glycol monomethyl ether (hereinafter abbreviated as M2) instead of M1, 3- [tris (trimethylsiloxy) silyl] propyl methacrylate (hereinafter abbreviated as M3) 26.2 g (62.0 mmol), 3- (trimethoxysilyl) propyl methacrylate (hereinafter abbreviated as M4) 26.2 g (105.5 mmol), 2- (dimethylamino) ethyl methacrylate (hereinafter, 26.2 g (166.7 mmol), glycidyl methacrylate (hereinafter abbreviated as M6) 26.2 g (184.3 mmol), tetrahydrofurfuryl methacrylate (hereinafter abbreviated as M7) 26.2 g (153.9 mmol), 2,2,6,6-tetramethacrylic acid 26.2 g (116.3 mmol) of til-4-piperidyl (hereinafter abbreviated as M8), 26.2 g (130.9 mmol) of 2-tert-butoxy-2-oxoethyl methacrylate (hereinafter abbreviated as M9), A block copolymer (A2 to A10) was obtained in the same manner as in Example 1 except that 26.2 g (129.5 mmol) of 2-trimethylsilyloxyethyl methacrylate (hereinafter abbreviated as M10) was used. It was. The results of GPC and ¹ H-NMR analysis are shown in Table 1.

<Example 11>
A block copolymer (A9) 10 g, toluene 100 g and p-toluenesulfonic acid monohydrate 100 mg (0.5 mmol) were added to a 200-ml four-necked flask equipped with a stirrer and a thermometer at 60 ° C. Stir for 3 hours. The obtained organic layer was dropped into 1000 g of methanol at 25 ° C. over 1 hour, and the precipitated solid was separated by filtration and dried under reduced pressure at 60 ° C. to obtain a block copolymer (A11) [polystyrene-polybutadiene-poly (methacrylic acid). 9.2 g of a triblock copolymer of 2-carboxymethyl). The results of GPC and ¹ H-NMR analysis are shown in Table 1.

<Example 12>
10 g of block copolymer (A10), 100 g of toluene, 30 ml of 1M tetrabutylammonium fluoride-tetrahydrofuran solution (30 mmol) were added to a 200-ml four-necked flask equipped with a stirrer and a thermometer, and the mixture was added at 25 ° C. for 3 hours. Stir. The obtained organic layer was dropped into 1000 g of methanol at 25 ° C. over 1 hour, and the precipitated solid was separated by filtration and dried under reduced pressure at 60 ° C. to obtain a block copolymer (A12) [polystyrene-polybutadiene-poly (methacrylic acid). 8.8 g of 2-hydroxyethyl)]. The results of GPC and ¹ H-NMR analysis are shown in Table 1.

<Examples 13 to 22>
In Examples 1 to 10, except that 0.9 g (5 mmol) of 1,1-diphenylethylene was used instead of Bd, the same operation as in Examples 1 to 10 was performed, and the block copolymer (A13 to 22) was obtained. Obtained. The results of GPC and ¹ H-NMR analysis are shown in Table 2.

<Example 23>
The inside of a 1 L four-necked flask equipped with a stirrer and a thermometer was purged with nitrogen, 105 g of cyclohexane, 0.30 g of cyclohexane solution of sec-butyllithium (equivalent to 0.49 mmol of sec-butyllithium), and St37 .9 g (363.6 mmol) was added and stirred at 25 ° C. for 4 hours. Next, while stirring this solution, 4.2 g of cyclohexane solution containing 0.4 g (4.9 mmol) of Bd was added and stirred at 25 ° C. for 1 hour. Subsequently, 105 g of toluene, 39.5 g of a toluene solution containing 19.7 mmol of isobutylbis (2,6-ditert-butyl-4-methylphenoxy) aluminum, and 10.5 g of 1,2-dimethoxyethane were separately mixed. The solution prepared above was added at 25 ° C. and cooled to 5 ° C., and 15.4 g (106.7 mmol) of 2-methoxyethyl methacrylate was added and stirred at 5 ° C. for 5 hours. After adding 3.0 g (93.8 mmol) of methanol to stop the polymerization, 300 g of toluene and 300 g of 5% acetic acid aqueous solution were added to the reaction mixture, and the mixture was stirred at 80 ° C. for 1 hour, and then left at 80 ° C. to stand for water. The layers were separated. The same washing operation was further performed 4 times using 300 g of 5% aqueous acetic acid solution, and then 300 g of distilled water was added and the mixture was stirred at 25 ° C. for 30 minutes and then allowed to stand at 25 ° C. to separate the aqueous layer. I went twice. The obtained organic layer was dropped into 4000 g of methanol over 1 hour at 25 ° C., and the precipitated solid was separated by filtration and dried under reduced pressure at 60 ° C. to obtain a block copolymer (A23) [polystyrene-polybutadiene-poly (methacrylic acid). 2-methoxyethyl) triblock copolymer] was obtained.
From GPC and ¹ H-NMR analysis, Mn of the block copolymer (A23) = 112210, Mw / Mn = 1.03, Mn of PSt block = 78100, Mn = 410 of PBd block, Mn of PM1 block = 33700 there were.

<Examples 24-32>
In Example 23, except that 15.4 g of M2 to M10 was used instead of M1, the same operation as in Example 23 was performed to obtain a block copolymer (A24 to A32). The results of GPC and ¹ H-NMR analysis are shown in Table 3.

<Example 33>
A block copolymer (A31) 10 g, toluene 100 g, and p-toluenesulfonic acid monohydrate 100 mg (0.5 mmol) were added to a 200-ml four-necked flask equipped with a stirrer and a thermometer at 60 ° C. Stir for 3 hours. The obtained organic layer was dropped into 1000 g of methanol at 25 ° C. over 1 hour, and the precipitated solid was separated by filtration and dried under reduced pressure at 60 ° C. to obtain a block copolymer (A33) [polystyrene-polybutadiene-poly (methacrylic acid). 2-carboxymethyl triblock copolymer] was obtained, and the results of GPC and ¹ H-NMR analysis are shown in Table 3.

<Example 34>
10 g of block copolymer (A32), 100 g of toluene, 50 ml of 1M tetrabutylammonium fluoride-tetrahydrofuran solution (50 mmol) were added to a 200-ml four-necked flask equipped with a stirrer and a thermometer, and 3 hours at 25 ° C. Stir. The obtained organic layer was dropped into 1000 g of methanol over 1 hour at 25 ° C., and the precipitated solid was separated by filtration and dried under reduced pressure at 60 ° C. to obtain a block copolymer (A34) [polystyrene-polybutadiene-poly (methacrylic acid). 2-hydroxyethyl)], 8.9 g. The results of GPC and ¹ H-NMR analysis are shown in Table 3.

<Examples 35-44>
In Examples 23 to 32, except that 0.45 g (2.5 mmol) of 1,1-diphenylethylene was used instead of Bd, the same operation as in Examples 23 to 32 was performed, and the block copolymer (A35 to 44) was obtained. The results of GPC and ¹ H-NMR analysis are shown in Table 4.

<Comparative Example 1>
The same operation as in Example 1 was performed except that the amount of Bd used was changed from 0.7 g (13.1 mmol) to 14.2 g (262.3 mmol) in Example 1, and the block copolymer (a1) [ Polystyrene-polybutadiene-poly (2-methoxyethyl methacrylate triblock copolymer)] was obtained.
From GPC and ¹ H-NMR analysis, Mw = 51400 of block copolymer (a1), Mw / Mn = 1.03, Mn = 21100 of PSt block, Mn = 9400 of PBd block, Mn = 20900 of PM1 block there were.

<Comparative Examples 2 to 10>
In the comparative example 1, except having used M2-M10 instead of M1, operation similar to the comparative example 1 was performed and the block copolymer (a2-a10) was obtained. The results of GPC and ¹ H-NMR analysis are shown in Table 5.

<Comparative Example 11>
In Example 11, except that a9 was used in place of A9, the same operation as in Example 11 was performed, and 8.9 g of a block copolymer (a11) [polystyrene-polybutadiene-poly (2-carboxymethyl methacrylate) was obtained. Obtained. The results of GPC and ¹ H-NMR analysis are shown in Table 5.

<Comparative Example 12>
In Example 12, except that a10 was used in place of A10, the same operation as in Example 12 was performed, and a block copolymer (a12) [polystyrene-polybutadiene-poly (2-hydroxyethyl methacrylate)] 9.0 g Got. The results of GPC and ¹ H-NMR analysis are shown in Table 5.

<Comparative Example 13>
The same operation as in Example 10 was performed except that the amount of Bd used was changed from 0.4 g (4.9 mmol) to 5.3 g (98 mmol) in Example 13, and the block copolymer (a13) [polystyrene- 44.8 g of polybutadiene-poly (2-methoxyethyl methacrylate) triblock copolymer] was obtained.
From GPC and ¹ H-NMR analysis, Mn of the block copolymer (a13) = 123200, Mw / Mn = 1.03, Mn of PSt block = 77900, Mn of PBd block = 9500, Mn of PMMA block = 35800 there were.

<Comparative Examples 14-22>
In Comparative Example 13, the same operation as in Comparative Example 13 was performed except that any one of M2 to 10 was used instead of M1, to obtain a block copolymer (a14 to a22). The results of GPC and ¹ H-NMR analysis are shown in Table 6.

<Comparative Example 23>
In Example 23, except having used a21 instead of A21, operation similar to Example 23 was performed and the block copolymer (a23) [polystyrene-polybutadiene-poly (carboxymethyl methacrylate 8.9g) was obtained. The results of GPC and ¹ H-NMR analysis are shown in Table 6.

<Comparative Example 24>
In Example 24, except that a22 was used instead of A22, the same operation as in Example 24 was performed, and a block copolymer (a24) [polystyrene-polybutadiene-poly (2-hydroxyethyl methacrylate)] 9.0 g Got. The results of GPC and ¹ H-NMR analysis are shown in Table 6.

<Preparation of self-assembling composition for pattern formation>
The block copolymers (A1 to A44, a1 to a24) were each dissolved in propylene glycol methyl ether acetate (PGMEA) to give a 1% by mass solution. These solutions were filtered through a membrane filter having a pore size of 0.2 μm to prepare a self-assembling composition for pattern formation, and a pattern was formed by the following method.

<Pattern formation method>
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science) was applied onto an 8-inch silicon wafer using a spinner and dried on a hot plate at 205 ° C. for 60 seconds to form a film. An organic antireflection film having a thickness of 80 nm was formed. Next, a random copolymer having a number average molecular weight of 40000 consisting of styrene / methyl methacrylate = 50/50 was dissolved in PGMEA at a concentration of 1.0 mass% on the organic antireflection film as a lower layer film. The solution was applied using a spinner and dried on a hot plate at 250 ° C. for 10 minutes to form a lower layer film having a thickness of 20 nm on the substrate. A chemically amplified resist composition “ARX2928JN” (trade name, manufactured by JSR) is applied on the formed lower layer film using a spinner, and dried on a hot plate at 120 ° C. for 60 seconds to form a resist film having a thickness of 60 nm. Formed. Next, using an ArF immersion exposure apparatus (NSR-S610C, manufactured by Nikon), exposure was performed through a mask pattern under the optical conditions of NA; 1.30, CrossPole, and σ = 0.777 / 0.78. . Thereafter, a post-exposure bake (PEB) treatment is performed at 115 ° C. for 60 seconds, and development is performed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 25 ° C. for 30 seconds, followed by washing with water and drying. / 120 nm pitch). Subsequently, the pre-pattern was irradiated with ultraviolet light of 254 nm under the condition of 150 mJ / cm ² and then baked at 170 ° C. for 5 minutes to obtain a substrate for evaluation.
Next, each pattern-forming self-assembling composition was applied onto the evaluation substrate with a spinner, and dried on a hot plate at 110 ° C. for 60 seconds to form a layer containing each block copolymer. Next, the substrate on which the layer containing the block copolymer was formed was heated in a nitrogen stream at 250 ° C. for 5 minutes to cause phase separation to form a microphase separation structure.
Thereafter, using TCA-3822 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.), the substrate was subjected to oxygen plasma treatment (200 sccm, 40 Pa, 200 W, 30 seconds) to selectively select a phase composed of polymethacrylate. The line and space pattern (1) and the hole pattern (2) were formed.

<Evaluation Examples 1 to 68>
The pattern (1) formed as described above is observed using a length measuring SEM (S-4800, manufactured by Hitachi, Ltd.), the width of the groove portion that appears white is measured, and the microphase separation structure width (nm) and did.
Moreover, about the pattern (1) formed as mentioned above, it observed from the pattern upper part using the scanning electron microscope (CG4000, Hitachi High-Technologies), and measured the line | wire width of the pattern in arbitrary 10 points | pieces. A 3-sigma value as a distribution degree was determined from the measured line width, and this value was defined as LWR (nm).
Table 7 shows the evaluation results of the microphase separation structure width and LWR. Note that “-” in Table 7 indicates that the microphase separation structure width and LWR could not be measured because the microphase separation structure was not formed. The case where LWR (nm) was 5 nm or less was judged as good, the case where it exceeded 5 nm, and the case where a microphase separation structure was not formed was judged as bad.

  The pattern (2) formed as described above is observed using a length measuring SEM (S-4800, manufactured by Hitachi, Ltd.), and from the diameter (nm) of the pre-pattern, the hole diameter (nm) of the obtained pattern The value which subtracted was calculated | required and this value was made into shrink amount (nm). Table 8 shows the evaluation results of the shrink amount. In addition, "-" in a table | surface shows that the amount of shrinkage (nm) was not able to be measured since the micro phase-separation structure was not formed. The case where the shrink amount (nm) was 30 nm or more was judged as good, the case where it was less than 30 nm, and the case where a microphase separation structure was not formed was judged as bad.

  As shown in Tables 7 and 8, when the self-assembling composition for pattern formation containing the block copolymers (A1 to A44) of the present invention as examples is used, the present invention as a comparative example is used. It was found that a sufficiently fine and good microphase separation structure can be obtained as compared with the case of using the self-assembling composition for pattern formation containing the outer block copolymers (a1 to a24). When the block copolymer (A1 to A44) of the present invention as an example was used, the obtained microphase separation structure was at least one selected from a cylindrical structure or a lamellar structure. On the other hand, in the self-assembling composition for pattern formation containing the block copolymer (a1 to a24) outside the present invention which is a comparative example, a microphase separation structure was not formed. Moreover, as shown in Table 8, in the case of using the self-assembling composition for pattern formation containing the block copolymer (A23 to A44) of the present invention which is an example, comparative examples (a13 to a24) It was found that the hole diameter of the hole pattern can be further reduced as compared with, and a sufficiently fine micro phase separation structure having a cylindrical structure can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the block copolymer (1) which can form a sufficiently fine and favorable pattern, the self-organization composition for pattern formation, and the pattern formation method can be provided. Therefore, the block copolymer (1), the self-assembling composition for pattern formation, and the pattern forming method of the present invention are a lithography process in manufacturing various electronic devices such as semiconductor devices and liquid crystal devices that are required to be further miniaturized. Is preferably used.

11 Substrate 12 Lower layer film 13 Self-assembled film 13a Polystyrene phase 13b Poly (meth) acrylate phase 14 Pre-pattern

Claims (7)

A block copolymer represented by the following general formula (1).

(In the formula, X represents a polymer block having a number average molecular weight of 1000 to 300,000 composed of a structural unit derived from a vinyl aromatic compound. Y represents a number average molecular weight of 50 to 3000 composed of a structural unit derived from a conjugated diene. It represents a structural unit derived from a polymer block or a diphenylethylene derivative.
Z is the formula (2)

(In the formula, R ¹ represents a hydrogen atom or a chain alkyl group having 1 to 6 carbon atoms. R ² represents an ether group, amino group, silyloxy group, imide group, ester group, carboxyl group, or hydroxyl group in the structure. It represents an organic group containing any one or more.) Represents a polymer block having a number average molecular weight of 1000 to 300000 consisting of a structural unit represented by )   The block copolymer according to claim 1, wherein Y is a polymer block having a number average molecular weight of 50 to 3000 consisting of a structural unit derived from a conjugated diene.   A microphase-separated structure which is obtained by performing a polymerization reaction of monomers stepwise by an anionic polymerization method and which is at least one selected from a cylindrical structure or a lamellar structure in an assembly of molecules can be formed. Item 3. The block copolymer according to item 1 or 2.   The self-organization composition for pattern formation containing the block copolymer (1) of Claims 1-3. A step 1 of forming a self-assembled film having a microphase separation structure on a substrate using the self-assembled composition for pattern formation according to claim 4; and removing a part of the phase of the self-assembled film. Step 2;
A pattern forming method including: Before the step 1, further comprising a step 0 comprising a step of forming a lower layer film on the substrate and a step of forming a pre-pattern on the lower layer film;
6. The pattern forming method according to claim 5, wherein in the step 1, a self-assembled film is formed in a region on the lower layer film delimited by the pre-pattern.   The pattern formation method of Claim 5 or 6 whose pattern obtained is a line and space pattern or a hole pattern.

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