JP2006293326A - Photosensitive composition and manufacturing process of structured material using the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition for forming a highly heat-resistant pattern of a microphase separation structure. <P>SOLUTION: The photosensitive composition comprises: (A) a block copolymer containing a segment, composed of an alkoxysilyl-group-containing monomer as a repeating unit, and (B) a photosensitive decomposition agent, where the polydispersity index (Mw/Mn) of the block copolymer is ≤1.8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photosensitive composition and a method for producing a structure comprising an inorganic substance in which a microphase separation structure pattern of a block copolymer of a smaller dimension is formed in a pattern formed by a photolithography process using the photosensitive composition. About. In particular, application to a low dielectric constant insulating film is expected.

  In recent years, the rapid progress of high speed, high functionality, small size, and light weight of electronic devices has been driven by high performance of LSI. Semiconductor integrated circuits (semiconductor ICs) developed as a central technology for transistors integrated on a chip in LSIs have made remarkable progress, and advanced microfabrication techniques are required for these semiconductor ICs. Lithography technology, which is a typical microfabrication technology, is batch exposure, so that it can cope with higher density in terms of throughput and has played a major role in realizing large-scale LSIs with higher integration. However, the physical limit (100 nm to several tens of nm) of the line width in the photolithography technique is pointed out. Techniques such as an immersion exposure method and electron beam lithography have been developed as a technique corresponding to this limit. However, as the number of microfabrication steps increases and the microfabrication size decreases, manufacturing costs such as equipment costs and operation costs increase, and the practical wall height is recognized from the viewpoint of processing speed. .

  As a method for overcoming the limitations of the lithography technique, a microstructure forming technique using self-organization of a block copolymer has been studied. As is well known in the field of polymer blends and polymer alloys, generally different polymers are incompatible with each other and their mixtures and block copolymers are in phase separation. In general, in polymer blends, the phase separation scale is macroscopic (macrophase separation) of several μm or more. On the other hand, in the block copolymer in which each component is linked by a covalent bond, the scale of the phase separation is regulated by the length of the block, so that a nanometer-sized fine and homogeneous phase separation state is stably provided.

  By using block copolymers having various molecular structures, the microphase separation structure can be controlled over a wide range. For example, the phase separation structure of the A block and the B block can be changed from the sea-island structure to the lamella structure by changing the mole fraction of the repeating units of the A block and the B block. Further, the domain size of the phase separation structure can be controlled by changing the molecular weight of the A block and the B block.

Examples of pattern formation using such a block copolymer microphase separation structure include the following examples. A method of forming a pattern on a silicon nitride substrate using a microphase separation structure of polystyrene (PS) -polybutadiene (PB) block copolymer as a template using a reactive ion etching (RIE) method has been reported (non-patent document). Reference 1). Also reported is a method for forming a nanostructure comprising an inorganic component from a microphase-separated structure of a coating film of a composition comprising a polyisoprene (PI) -polyethylene oxide (PEO) block copolymer, a silane coupling agent, and a metal alkoxide. (Non-Patent Document 2). Furthermore, a method of manufacturing various electronic components such as a high-density magnetic recording medium by forming a pattern using PS-PMMA block copolymer and the like, selectively removing one component by etching, and then transferring the pattern to the substrate Is disclosed (Patent Document 1).
Science, 1997, 276, 1401 Advanced Materials, 1999, 11, page 141 JP 2002-287377 A

  However, the above-described pattern forming method using the microphase-separated structure of the block copolymer disclosed so far has a heat resistance as a template because the block chain constituting the block copolymer is mainly composed of an organic component. There was a problem of being low.

  Then, in order to solve the above-mentioned subject, this invention aimed at providing the photosensitive composition for forming the pattern of the micro phase-separation structure with high heat resistance.

The present invention
(A) a block copolymer including a segment having a monomer containing an alkoxysilyl group as a repeating unit;
(B) a photosensitive decomposing agent,
The present invention provides a photosensitive composition in which the block polymer has a molecular weight distribution index (Mw / Mn) of 1.8 or less.

The present invention also provides:
A method for producing a structure including a microphase separation structure,
A manufacturing method including the following steps is provided.
(1) (A) a block copolymer including a segment having a repeating unit of an alkoxysilyl group-containing monomer having a molecular weight distribution index (Mw / Mn) of 1.8 or less, and (B) photosensitive decomposition A step of exposing a film comprising a composition containing an agent (2) a step of developing the film after the exposure step (3) a step of heating the film after the exposure step

  A composition containing a block copolymer composed of a repeating unit containing an inorganic component in one segment can form a pattern having a smaller dimension in a photolithography pattern. As a result, it is possible to form a layered structure having high heat resistance and solvent resistance, which has not been conventionally used.

The first embodiment of the present invention
(A) a block copolymer including a segment having a monomer containing an alkoxysilyl group as a repeating unit;
(B) a photosensitive decomposing agent,
The present invention provides a photosensitive composition in which the block polymer has a molecular weight distribution index (Mw / Mn) of 1.8 or less.

  Furthermore, it is preferable that this composition contains (C) a compound capable of crosslinking (A) in the presence of an acid or a base.

  First, (A) a block copolymer containing as a component a segment composed of a monomer containing an alkoxysilyl group as a repeating unit will be described. A block copolymer is a polymer in which homopolymer chains of two or more monomers are combined in one molecule. For example, a block copolymer including segment A and segment B is a two-component AB type block copolymer. However, the present invention is not limited to this, and an ABC type, ABA type, BAB type triblock copolymer containing three components or a multiblock copolymer containing more components may be used.

  The block copolymer used in the present invention contains a monomer comprising an alkoxysilyl group in at least one block constituting the block copolymer as a repeating unit. The alkoxysilyl group is represented by the following general formula (1), and includes at least one alkoxysilyl group in the monomer.

（ここで、Ｒ^１およびＲ^２は同一であっても異なっていてもよく、それぞれ１価の有機基であり、そしてｎは０から２の整数である。）

(Wherein R ¹ and R ² may be the same or different, each is a monovalent organic group, and n is an integer of 0 to 2).

  In the above formula (1), examples of the monovalent organic group include an alkyl group, an alicyclic group, an aryl group, an allyl group, and a glycidyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. The preferable carbon number of the alkyl group is 1-10. These alkyl groups may be linear or branched, and a hydrogen atom may be substituted with a halogen atom such as a fluorine atom. Examples of the alicyclic group include a cyclohexyl group and a norbornyl group. Examples of the aryl group include a phenyl group and a naphthyl group. In the above formula (1), n is preferably 0 or 1. The type of these alkoxysilyl groups may be selected from the viewpoints of desired hydrolyzability, reaction rate, availability, cost, etc., and is not particularly limited, and these alkoxysilyl groups contained in one monomer molecule There is no particular limitation as long as the number of silyl groups is one or more.

  More specific examples of the monomer containing an alkoxysilyl group are represented by the following general formulas (2) to (4).

In the above formula, R ³ represents a hydrogen atom or a methyl group. R ⁴ is an alkylene group, an alkylenearylenealkylene group, an arylene group, an alkylsilylene group, or a single bond, and the alkylene group is represented by —O—, —CO—, —COO—, —OCOO—, —S—, It may contain a —SO ₂ — or —CONH— bond. R ^{5 to} R ⁸ are the same as or different from each other, and are a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or other (halogenated) alkyl group having 1 to 10 carbon atoms, a phenyl group, p-fluorophenyl Group, naphthyl group, aromatic substituted alkyl group such as benzyl group, hydroxylalkyl group, alkoxyalkyl group, cyano group, carboxyl group, alkylcarbonyloxy group, alkyloxycarbonyl group, or hydroxyl group, amino group, carbonyl group, mercapto group , A substituent selected from an aldehyde group, an amide group, and a sulfonyl group.

  Examples of the compound represented by the above (2) include γ- (methacryloyloxypropyl) trimethoxysilane, γ- (methacryloyloxypropyl) triethoxysilane, γ- (methacryloyloxypropyl) tripropoxysilane, and γ- (methacryloyl). Oxypropyl) triisopropoxysilane, γ- (methacryloyloxypropyl) tributoxysilane, γ- (acryloyloxypropyl) triethoxysilane, γ- (acryloyloxypropyl) tripropoxysilane, γ- (acryloyloxypropyl) triiso Propoxysilane, γ- (acryloyloxypropyl) tributoxysilane, and the like are used, but are not particularly limited thereto.

  Examples of the compound represented by the above (3) include vinylbenzyltrimethoxysilane, vinylbenzyltriethoxysilane, vinylbenzyltripropoxysilane, vinylbenzyltriisopropoxysilane, vinylbenzyltributoxysilane, vinylbenzyltrimethoxydimethyldisilane. However, it is not particularly limited to these.

  Examples of the compound represented by (4) include (3-acrylamidopropyl) trimethoxysilane, (3-acrylamidopropyl) triethoxysilane, (3-acrylamidopropyl) tripropoxysilane, and (3-acrylamidopropyl) tri Isopropoxysilane, (3-acrylamidopropyl) tributoxysilane, (3-methacrylamidopropyl) trimethoxysilane, and the like are used, but not particularly limited thereto.

  As other alkoxysilyl group-containing unsaturated compounds, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane and the like can be used.

  In the present invention, the volume fraction of the block containing the alkoxysilyl group-containing monomer as a repeating unit contained in one molecule of the block copolymer is particularly a ratio that forms a desired microphase separation structure. Although not limited, it is desirable to be 5 to 95%. If it is 5% or less or 95% or more, it may be difficult to form a microphase separation structure.

  The method for producing a block copolymer containing as a component a segment having an alkoxysilyl group-containing monomer as a repeating unit in the present invention is based on the living polymerization method, and the living radical polymerization method is particularly preferably used. Various techniques have been developed in recent years for the living radical polymerization method, and examples include the following. For example, Macromol. Chem. Rapid Commun. 1982, Vol. 3, page 133, Iniferter polymerization, Macromolecules, 1994, Vol. 27, page 7228 using a radical scavenger such as a nitroxide compound, Journal of・ The American Chemical Society (J. Am. Chem. Soc.), 1995, Vol. 117, p. 5614, as an initiator and transition metal complex as a catalyst. “RAFT: Reversible Addition-Fragme” shown in “Atom Transfer Radical Polymerization (ATRP)”, Macromolecules, 1998, Vol. 31, p. tationchain Transfer polymerization ", and the like, such as. Among these, although the present invention is not particularly limited, a synthesis method by an atom transfer radical polymerization method is particularly preferably used.

  As an initiator in this atom transfer radical polymerization method, an organic halide, particularly an organic halide having at least one highly reactive carbon-halogen bond in the molecule (for example, a compound having a halogen at the α-position or a benzyl position). A compound having a halogen), a sulfonyl halide compound, and the like can be preferably used.

  Specifically, 1-phenylethyl chloride, 1-phenylethyl bromide, chloromethylstyrene, chloroform, carbon tetrachloride, carbon tetrabromide, 2-chloropropionitrile, 2-bromopropionitrile, 2-chloroisopropionitrile. Ethyl onate, methyl 2-chloroisopropionate, ethyl 2-chloroisopropionate, methyl 2-bromoisopropionate, ethyl 2-bromoisopropionate, methyl 2-bromoisobutyrate, ethyl 2-bromoisobutyrate, chloroacetic acid Vinyl, p-toluenesulfonic acid chloride, perfluoroethyl iodide, perfluoropropyl iodide, perfluorobutyl iodide, 2,2-bis (chloromethyl) -1,3-dichloropropane, 2,2-bis ( Bromomethyl) -1,3-dichloropropane, ,. Alpha .'- dibromo-xylene, and hexakis (alpha-chloromethyl) - can be exemplified benzene.

  When the atom transfer radical polymerization method is used, the radical polymerizable monomer is subjected to living radical polymerization using a halogen-containing metal complex as a catalyst together with the polymerization initiating group. As the metal catalyst, a catalyst composed of a metal complex in which at least one transition metal (M) selected from Groups 7 to 11 of the periodic table is a central metal is used. Is a metal selected from the group consisting of Cu, Ni, Pd, Pt, Rh, Co, Ir, Fe, Ru, Re, and Mn. Among them, Cu, Ru, Fe, and Ni are preferable, and copper is particularly preferable. . When copper is used as the central metal of the halogen-containing metal complex, cuprous chloride and cuprous bromide are particularly preferably used as the halogen-containing copper complex, but are not particularly limited thereto.

  An organic ligand is used for the above metal complex. Organic ligands are used to allow solubilization in polymerization solvents and reversible redox reactions of metal complexes. Examples of the coordination atom to the metal include a nitrogen atom, an oxygen atom, a phosphorus atom, and a sulfur atom, and a nitrogen atom is preferable. Specific examples of the organic ligand include 2,2′-bipyridyl and its derivatives, tetramethylethylenediamine, pentamethyldiethylenetriamine, hexamethyltriethylenetetraamine, tris (dimethylaminoethyl) amine, triphenylphosphine, and the like. However, it is not limited to these.

  Since the polymer obtained by the above atom transfer radical polymerization method has a halogen terminal X capable of initiating further polymerization, the first monomer is consumed in the polymerization to form the first block chain. After formation, a second monomer can be added to form a second block chain that grows from the end of the first block chain. That is, it is possible to produce a block copolymer comprising a block chain having the above-mentioned monomer containing an alkoxysilyl group as a repeating unit and a block chain having another monomer as a repeating unit. Further, a multi-block copolymer can be produced. The order in which the block copolymerization is performed may be the order in which either the monomer containing the alkoxysilyl group or the other monomer comes first, or may be a multi-block polymer composed of three or more types of monomers.

  In the present invention, a known radical polymerizable monomer can be used for the monomer constituting the block not containing an alkoxysilyl group. The unsaturated monomers that can be used in the radical polymerization method of the present invention can be exemplified below, but are not particularly limited thereto.

  Styrene, α-, o-, m-, p-alkyl of styrene, alkoxyl, halogen, haloalkyl, nitro, cyano, amide, ester substituted product; styrene sulfonic acid, 2,4-dimethylstyrene, paradimethylaminostyrene, vinyl Polymerizable unsaturated aromatic compounds such as benzyl chloride, vinylbenzaldehyde, indene, 1-methylindene, acenaphthalene, vinylnaphthalene, vinylanthracene, vinylcarbazole, 2-vinylpyridine, 4-vinylpyridine and 2-vinylfluorene.

  Alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate; methyl crotonic acid, crotonic acid Unsaturated monocarboxylic esters such as ethyl, methyl cinnamate and ethyl cinnamate; fluoroalkyl (meta) such as trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate and heptafluorobutyl (meth) acrylate ) Acrylates; trimethylsiloxanyldimethylsilylpropyl (meth) acrylate, tris (trimethylsiloxanyl) silylpropyl (meth) acrylate, di (meth) acryloylpropyldimethylsilyl Siloxanyl compounds such as ether; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate; dimethylaminoethyl (meth) acrylate Amine-containing (meth) acrylates such as diethylaminoethyl (meth) acrylate and t-butylaminoethyl (meth) acrylate; 2-hydroxyethyl crotonic acid, 2-hydroxypropyl crotonic acid, 2-hydroxypropyl cinnamate, etc. Hydroxyalkyl esters of unsaturated carboxylic acids; unsaturated alcohols such as (meth) allyl alcohol; unsaturated (mono) carboxylic acids such as (meth) acrylic acid, crotonic acid and cinnamic acid; (meth) acrylic Glycidyl acid, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate, glycidyl α-n-butyl acrylate, (meth) acrylic acid-3,4-epoxybutyl, (meth) acrylic acid-6,7 -Epoxyheptyl, α-ethylacrylic acid-6,7-epoxyheptyl, o-vinylbenzylglycidyl ether, m-vinylbenzylglycidylether, p-vinylbenzylglycidylether, (meth) acrylic acid-β-methylglycidyl, ( (Meth) acrylic acid-β-ethylglycidyl, (meth) acrylic acid-β-propylglycidyl, α-ethylacrylic acid-β-methylglycidyl, (meth) acrylic acid-3-methyl-3,4-epoxybutyl, ( Meth) acrylic acid-3-ethyl-3,4-epoxybutyl, (meth) acrylic Acid-4-methyl-4,5-epoxypentyl, (meth) acrylic acid-5-methyl-5,6-epoxyhexyl, (meth) acrylic acid-β-methylglycidyl, (meth) acrylic acid-3-methyl -Epoxy group-containing (meth) acrylic acid esters such as 3,4-epoxybutyl; and mono- and diesters thereof.

  In addition, N-alkyl-substituted (meth) acrylamides such as N, N-dimethylacrylamide and N-isopropylacrylamide; N-methylolacrylamide, N-methylolmethacrylamide, N-vinylpyrrolidone, (anhydrous) maleic acid, fumaric acid, (Anhydrous) Unsaturated polycarboxylic acids (anhydrides) such as itaconic acid and citraconic acid, vinyl chloride, vinyl acetate and the like. The radically polymerizable monomers exemplified above can be used alone or in combination of two or more.

As for the polymer constituting the segment not containing an alkoxysilyl group, in addition to the polymer of the radical polymerizable monomer, a polymer having an ester group or an ether group in the main chain, particularly an aliphatic polyester polymer or An aliphatic polyether-based polymer can be preferably used. These polymers generally have a lower thermal decomposition temperature than a polymer having a C—C bond in the polymer main chain obtained by radical polymerization, so that a structure can be formed even at a low firing temperature, and a carbon (coke) residue after firing. This is useful for the purposes of the present invention. These may use a commercially available thing, and may synthesize | combine as needed.
The ester unit constituting the aliphatic polyester in the present invention may have any structure as long as the ester unit does not contain an aromatic ring, but includes an ester structure represented by the following formulas (5) to (7). It is preferable.

（式中、Ｒ^９は炭素数１〜１０の直鎖状または分岐状アルキレン基を示す。）

(In the formula, R ⁹ represents a linear or branched alkylene group having 1 to 10 carbon atoms.)

（式中、Ｒ^１０は炭素数１〜６の直鎖状または分岐状アルキレン基、Ｒ^１１は炭素数２〜１２の直鎖状または分岐状アルキレン基を示す。）

(In the formula, R ¹⁰ represents a linear or branched alkylene group having 1 to 6 carbon atoms, and R ¹¹ represents a linear or branched alkylene group having 2 to 12 carbon atoms.)

(In the formula, R ¹² represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms.)

R ¹² in Formula (7) may be two or more different types (copolymers) selected from a hydrogen atom and an alkyl group having 1 to 12 carbon atoms. When R ¹² is a methyl group, it is poly (3-hydroxybutyric acid), and when R ¹² is a methyl group and a hydrogen atom, it is a 3-hydroxybutyric acid / 3-hydroxypropionic acid copolymer, and R ¹² is a methyl group and In the case of an ethyl group, it is a 3-hydroxybutyric acid / 3-hydroxyvaleric acid copolymer. Formulas (5) to (7) may be used alone or in combination.

  Polymers represented by these formulas (5) to (7) include hydroxy acid polycondensates, lactone ring-opening polymers, and polymers of α, ω-aliphatic dicarboxylic acids and α, ω-aliphatic diols. Examples include condensates. Specific examples of the polymer include a hydroxy acid polycondensate such as a hydroxybutyric acid polycondensate, and a polyester obtained by polycondensation of an α, ω-aliphatic dicarboxylic acid and an α, ω-aliphatic diol. , Polyethylene succinate, polybutylene succinate, polypentamethylene succinate, polyhexamethylene succinate, and polyethylene adipate, polypentamethylene adipate, polyhexamethylene adipate, and the like as lactones such as poly α-propiolactone, poly β-propiolactone, polyβ-butyrolactone, polypivalolactone, polyα-valerolactone, polyγ-valerolactone, polyε-caprolactone and the like, and lactide include polylactide, polyglycolide and the like. It is not limited.

The ether unit constituting the aliphatic polyether in the present invention may be any structure as long as it is an ether unit not containing an aromatic ring, but from the viewpoint of ease of decomposition and availability, a polymethylene oxide structure, Examples include a polyethylene oxide structure, a polypropylene oxide structure, a polytetramethylene oxide structure, and a polybutylene oxide structure. Specifically, ether type compounds such as polyoxymethylene alkyl ether, polyoxyethylene alkyl ether, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene-polyoxypropylene alkyl ether, polyoxyethylene glycerin fatty acid ester, polyoxyethylene Ether ester type compounds such as oxyethylene sorbitan fatty acid ester and polyoxyethylene sorbitol fatty acid ester, ether ester type such as polyethylene glycol fatty acid ester, ethylene glycol fatty acid ester, fatty acid monoglyceride, polyglycerin fatty acid ester, sorbitan fatty acid ester and propylene glycol fatty acid ester Although a compound etc. can be mentioned, it does not specifically limit to these. Further, since the aliphatic polyester can be synthesized starting from hydroxyl groups present at both ends or one end of the aliphatic polyether polymer, the polymer constituting the block containing no alkoxysilyl group in the present invention is a polyether. It may be a copolymer of a polymer and a polyester polymer.
A living polymerization method is also suitably used as a method for synthesizing a block copolymer in which the aliphatic polyester-based or aliphatic polyether-based polymer is a segment not containing an alkoxysilyl group, but there is no particular limitation. Further, even when the living polymerization method is used, (1) a polymer obtained by polymerization of a monomer containing an alkoxysilyl group is directly used as it is, or a functional group conversion of a polymer polymer terminal is performed, (2) After synthesizing an aliphatic polyester or aliphatic polyether, a monomer containing an alkoxysilyl group is polymerized directly or by functional group conversion at the end. Also good. As the aliphatic polyester or aliphatic polyether (2), a commercially available compound may be obtained and used.

  As the polymerization solvent used in the present invention, any type of solvent can be used as long as it has no inhibitory action on radical polymerization, but among them, it has a structure that is compatible with the monomer used for polymerization and does not become a radical polymerization initiation species. A solvent is advantageous in terms of polymerization control. Also, if water is contained in the solvent, the hydrolysis reaction of the alkoxysilyl group proceeds during the polymerization reaction, and the desired block copolymer may not be obtained, so the water in the polymerization solvent is removed. It is preferable. Typical examples of the polymerization solvent are illustrated.

  Methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol , Isopentyl alcohol, tert-pentyl alcohol, 1-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethyl-1-hexanol, benzyl alcohol, cyclohexanol, and the like; methyl cellosolve Ether alcohols such as ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, diethylene glycol monobutyl ether; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone Ketones; esters such as ethyl acetate, butyl acetate, ethyl propionate, cellosolve acetate; pentane, 2-methylbutane, n-hexane, cyclohexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethyl Butane, heptane, n-octane, isooctane, 2,2,3-trimethylpentane, decane, nonane, cyclopentane, methylcyclopentane, methylcyclohexane, ethylcyclohexane, p-menthane, dicyclohexyl, benzene, toluene, xylene, ethylbenzene, Aliphatic or aromatic hydrocarbons such as anisole (methoxybenzene); ethers such as ethyl ether, dimethyl ether, trioxane, tetrahydrofuran and diphenyl ether; acetals such as methylal and diethyl acetal Tars; formic acid, acetic acid, fatty acids such as acetic acid and propionic acid; nitro propene, nitrobenzene, dimethylamine, monoethanolamine, pyridine, dimethyl formamide, dimethyl sulfoxide, sulfur such as acetonitrile, nitrogen-containing organic compounds, and the like. These are not particularly limited except for the above solvent conditions, and a solvent suitable for the use of the polymerization method may be selected as appropriate. These may be used alone or in combination of two or more.

  The atom transfer radical polymerization in the present invention can be carried out in various forms, and examples thereof include solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization. In carrying out the present invention, there are no particular restrictions on the procedure for adding a polymerization reagent, but a radical polymerizable monomer, a polymerization initiator, a metal catalyst, and a ligand as necessary are mixed and further required. Accordingly, an appropriate solvent is added, and after deaeration and replacement with an inert gas, the reaction is performed at a predetermined temperature. The polymerization temperature is usually selected between 5 and 140 ° C, preferably between 20 and 120 ° C. When the polymerization temperature is less than 5 ° C., the polymerization reaction is extremely slow, which is not industrially preferable. On the other hand, when the polymerization temperature exceeds 140 ° C., the tendency of the molecular weight distribution to become wide is increased, which is not preferable.

  In the present invention, the narrower the molecular weight distribution of the block copolymer containing as a component a segment having an alkoxysilyl group-containing monomer as a repeating unit, the better. The molecular weight distribution index (Mw / Mn) serving as the index is confirmed by gel permeation chromatography (GPC). The molecular weight distribution index (Mw / Mn) of the block copolymer of the present invention is preferably 1.8 or less, and more preferably 1.5 or less. When applied to an electronic device, the high uniformity of the block polymer makes it possible to provide a structure with high periodicity, and the device as a whole can have high performance. When the molecular weight distribution index is large, the periodicity and size of the microphase separation structure tend to be disturbed.

  Next, (B) the photosensitive decomposing agent will be described. The (B) photosensitive decomposition agent used in the present invention can be a photosensitive acid generator or a photosensitive base generator.

  As the photosensitive acid generator, a known compound can be arbitrarily selected and used as long as it is a compound that generates an acid upon irradiation with actinic rays. For example, diazonium salts, iodonium salts, bromonium salts, chloronium salts, sulfonium salts, onium salts such as selenonium salts, pyridinium salts and the like, halogen compounds such as halogen-containing triazines, sulfonylimide compounds, and the like, preferably diphenyliodonium Iodonium salts such as trifluoromethyl sulfonate, sulfonium salts such as triphenylsulfonium hexafluoroantimonate, halogen-containing triazines, sulfonate esters, and the like can be used.

  Examples of the iodonium salt include diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphonate, diphenyliodonium hexafluoroarsenate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium-p-toluenesulfonate, diphenyliodonium. Butyltris (2,6-difluorophenyl) borate, diphenyliodonium hexyltris (p-chlorophenyl) borate, 4-methoxyphenylphenyliodonium tetrafluoroborate, 4-methoxyphenylphenyliodonium hexafluorophosphonate, 4-methoxyphenylphenyliodonium hexa Fluoroarsene DOO, 4-methoxyphenyl phenyl iodonium trifluoromethanesulfonate, 4-methoxyphenyl phenyl iodonium trifluoroacetate, can be used 4-methoxyphenyl phenyl iodonium -p- toluenesulfonate and the like.

  Examples of the sulfonium salt include triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphonate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p. -Toluenesulfonate, 4-methoxyphenyldiphenylsulfonium tetrafluoroborate, 4-methoxyphenyldiphenylsulfonium-p-toluenesulfonate, 4-phenylthiophenyldiphenylsulfonium hexafluorophosphonate, 4-phenylthiophenyldiphenylsulfonium hexafluoroarsenate 4-phenylthiophenyldiphenylsulfur Trifluoromethane sulfonate or the like can be used.

  Examples of the halogen-containing triazines include tris (2,4,6-trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, and 2- (4-chlorophenyl). -4,6-bis (trichloromethyl) -s-triazine, 2- (3-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (2-chlorophenyl) -4,6-bis (Trichloromethyl) -s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, tris (trichloromethyl) -s-triazine and the like can be used.

  Examples of the sulfonic acid esters include α-hydroxymethylbenzoin-p-toluenesulfonic acid ester, α-hydroxymethylbenzoin-trifluoromethanesulfonic acid ester, α-hydroxymethylbenzoin-methanesulfonic acid ester, 2,4-dinitro Benzyl-p-toluenesulfonate, 2,4-dinitrobenzyl-trifluoromethanesulfonate, 2,4-dinitrobenzyl-methanesulfonate, 2,4-dinitrobenzyl-1,2-naphthoquinonediazide-5 Sulfonic acid ester, 2,6-dinitrobenzyl-p-toluenesulfonic acid ester, 2-nitrobenzyl-p-toluenesulfonic acid ester, 2-nitrobenzyl-trifluoromethanesulfonic acid ester, 2-nitroben Ru-methanesulfonic acid ester, 4-nitrobenzyl-p-toluenesulfonic acid ester, 4-nitrobenzyl-trifluoromethanesulfonic acid ester, 4-nitrobenzyl-methanesulfonic acid ester, 4-nitrobenzyl-1,2-naphtho Quinonediazide-5-sulfonic acid ester and the like can be used.

  As the photosensitive base generator, for example, those described in JP-A-4-330444, “Polymer” p242-248, 46, 6 (1997), and the like are preferably used. Examples include triphenylmethanol and benzylcarbamate. However, it is not limited to these as long as a base is generated by irradiation with actinic rays as a function.

  The photosensitive acid generator or the photosensitive base generator can be used alone or in combination of a plurality of photosensitive acid generators or photosensitive base generators. The (B) photosensitive decomposing agent is preferably used in an amount of 0.01 parts by mass or more, more preferably 0.05 parts by mass or more based on 100 parts by mass of the (A) block copolymer. (B) When a component is less than 0.01 mass part, the sensitivity with respect to irradiation light will fall easily. The upper limit is preferably 20 parts by mass or less, more preferably 15 parts by mass or less. When the component (B) is 20 parts by mass or more, a development residue tends to remain in the obtained coating film.

Next, (C) the compound that can crosslink the block polymer containing an alkoxysilyl group in the presence of an acid or base used in the present invention will be described. As a compound capable of crosslinking the block polymer containing an alkoxysilyl group, a metal alkoxide represented by the following formula (5) and a metal halide represented by the following formula (6) M (OR) _t Y _u. 5)
MX _t Y _u (6)
(In the above formulas (5) and (6), M represents a +2 to pentavalent atom, R represents an alkyl group or an aryl group, Y represents a hydrogen atom, an alkyl group, an aryl group, a hydroxyl group, an alkoxyl group) Or an aryloxy group, X represents a halogen atom, and t and u are 0 or an integer of 1 or more, provided that t + u is equal to the valence of atom M). Compounds can also be used.

  As the +2 to pentavalent atom M in the above formulas (5) and (6), for example, Si, P or a metal atom can be used. As the metal atom, for example, atoms of 2A group, 3B group and transition metal of the periodic table are preferable.

  The alkyl group contained in all the alkyl groups and alkoxyl groups may be a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, and some or all of the hydrogen atoms contained in them may be It is substituted with a chlorine atom, bromine atom, perfluoroalkyl group, hydroxyl group, mercapto group, thioalkyl group, alkoxyl group, alkyl ester group, alkylthioester group, perfluoroalkyl ester group, cyano group, nitro group or aryl group. There may be.

  The aryl groups in all the aryl groups and aryloxy groups are independently of each other, for example, a phenyl group, a naphthyl group, an anthracenyl group or a biphenyl group, and their hydrogen atoms are chlorine, bromine, hydroxyl, mercapto, alkoxy And those substituted with a group, a thioalkyl group, an alkyl ester group, an alkylthioester group, a cyano group or a nitro group.

  Moreover, as a halogen atom, the atom of a fluorine, chlorine, and a bromine can be mentioned as a preferable thing, for example.

  When the compound represented by the above formula (5) is shown, for example, as a silicon compound, tetramethoxysilane, tetraethoxysilane (commonly referred to as TEOS), tetra-n-propyloxysilane, tetraisopropyloxysilane, tetra-n-butoxysilane Tetraalkoxysilanes such as: methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, cyclohexyltriethoxysilane, and other monoalkyltrialkoxysilanes; phenyltriethoxysilane, naphthyltriethoxysilane, 4-chlorophenyltriethoxysilane, 4 Monoaryltrialkoxysilanes such as methylphenyltriethoxysilane; phenoxytriethoxysilane, naphthyloxytriethoxysilane, 4-chlorophenyloxytriethoxysila Monoaryloxytrialkoxysilanes such as 4-methylphenyloxytriethoxysilane; monohydroxytrialkoxysilanes such as monohydroxytrimethoxysilane and monohydroxytriethoxysilane; dialkyldialkoxys such as dimethyldimethoxysilane and dimethyldiethoxysilane Silanes; monoalkyl monoaryl dialkoxysilanes such as methyl (phenyl) diethoxysilane; monoalkyl monohydroxy dialkoxysilanes such as methyl (hydroxy) dimethoxysilane; trialkylmonoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane; In addition, oligomers of the above compounds such as dimers and pentamers of tetramethoxysilane can be used.

  Specific examples of the compound represented by the above formula (6) are exemplified as silicon compounds: tetrahalogenosilanes such as tetrachlorosilane, tetrabromosilane, tetraiodosilane, trichlorobromosilane, dichlorodibromosilane; methyltrichlorosilane, methyldichloro Monoalkyltrihalogenosilanes such as bromosilane and cyclohexyltrichlorosilane; monoaryltrihalogenosilanes such as phenyltrichlorosilane, naphthyltrichlorosilane and 4-chlorophenyltrichlorosilane; monoaryloxytrihalogenos such as phenoxytrichlorosilane and phenoxydichlorobromosilane Silane; monoalkoxytrihalogenosilane such as methoxytrichlorosilane and ethoxytrichlorosilane; dimethyldichlorosilane, methyl Dialkyldihalogenosilanes such as ethyl) dichlorosilane and methyl (cyclohexyl) dichlorosilane; monoalkylmonoaryldihalogenosilanes such as methyl (phenyl) dichlorosilane; and oligomers of the above compounds such as dimer to pentamer of tetrachlorosilane Can be used.

  Examples of the compound represented by the above formula (5) or the above formula (6) include triethoxy boron, trichloro boron, diethoxy magnesium, dichloro magnesium, triethoxy aluminum, tributoxy aluminum, trichloro aluminum, triethoxy phosphorus, Trichloroline, pentaethoxyline, pentachloroline, tetraethoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium, tetrachlorotitanium, diethoxyiron, dichloroiron, triethoxyiron, trichloroiron, diethoxynickel, dichloronickel, triethoxygallium , Trichlorogallium, tetramethoxygermanium, tetraethoxygermanium, tetrachlorogermanium, diethoxystrontium, dichlorostrontium, trie Xy yttrium, trichloro yttrium, tetramethoxy zirconium, tetraethoxy zirconium, tetrabutoxy zirconium, tetrachloro zirconium, diethoxy cadmium, dichloro cadmium, triethoxy indium, trichloro indium, diethoxy barium, dichloro barium, hexaethoxy tungsten, hexachloro tungsten, Alkoxides and halides such as pentaethoxy tantalum, pentachloro tantalum, diethoxy lead, dichloro lead, triethoxy bismuth, trichloro bismuth can be used as well.

  Among these, tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane; trialkoxyaluminums such as tributoxyaluminum; tetraalkoxytitanium such as tetrabutoxytitanium; tetraalkoxyzirconium such as tetrabutoxyzirconium and tetrahalogeno such as tetrachlorosilane Silane; trihalogenoaluminum such as trichloroaluminum; tetrahalogenotitanium such as tetrachlorotitanium and the like are preferably used.

  The component (C) can be used alone or in combination of a plurality of compounds. The content of the compound of component (C) in the composition can be freely set according to mechanical characteristics and exposure / development characteristics in the photolithography process. It is preferably used in an amount of not more than part by mass, more preferably not more than 60 parts by mass. When the component (C) exceeds 100 parts by mass with respect to 100 parts by mass of the component (A), the degree of crosslinking becomes too high and it may be difficult to form a microphase separation structure. The lower limit of the component (C) is freely determined according to the characteristics and process of the target nanostructure, but is usually 0.1 parts by mass or more with respect to 100 parts by mass of the component (A). When it is set as the composition containing the said (C) component, it is preferable to use 0.01 mass part or more of (B) photosensitive decomposition agents with respect to 100 mass parts of (A) block copolymers, and 0.05 mass. It is more preferable to use more than one part. (B) When a component is less than 0.01 mass part, the sensitivity with respect to irradiation light will fall easily. The upper limit of component (B) is preferably 20 parts by mass or less, more preferably 15 parts by mass or less. When the component (B) is 20 parts by mass or more, a development residue tends to remain in the obtained coating film.

  The photosensitive composition used in the present invention may contain other additives as long as the object of the present invention is not impaired. Examples of such additives include silane coupling agents, sensitizers, ultraviolet absorbers, and surfactants.

  For example, as the silane coupling agent, 3-glycidyloxypropyltrimethoxysilane, 3-aminoglycidyloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 1-methacryloxypropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-trimethoxy Rylpropyltriethylenetriamine, N-triethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, N-benzyl-3- Aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane and the like are used. These may be used alone or in combination of two or more.

  For example, specific examples of the sensitizer include benzoin, benzoin methyl ether, benzoin ethyl ether, 9-fluorenone, 2-chloro-9-fluorenone, 2-methyl-9-fluorenone, 9-anthrone, 2 -Bromo-9-anthrone, 2-ethyl-9-anthrone, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, 2-t-butyl-9,10-anthraquinone, 2,6-dichloro-9 , 10-anthraquinone, xanthone, 2-methylxanthone, 2-methoxyxanthone, thioxanthone, benzyl, dibenzalacetone, p- (dimethylamino) phenyl styryl ketone, p- (dimethylamino) phenyl p-methylstyryl ketone, benzophenone , P- (dimethylamino) benzophenone N-phenyl-1-nastilamine, N, N-diphenyl-1-naphthylamine, aminopyrene, N-phenylaminopyrene, N, N-diphenylaminopyrene, N-chlorophenylaminopyrene, N, N-dichlorophenylaminopyrene, triphenyl Amine, P-hydroxytriphenylamine, N-phenyl-N-benzyl-1-naphthylamine, N-phenyl-N-styryl-1-naphthylamine and the like are used.

  Next, the formation method of the nanostructure which consists only of an inorganic component using the said photosensitive composition is demonstrated. When the photosensitive composition of the present invention is used, it is dissolved in a solvent so that the solid content concentration is, for example, 0.1 to 50% by mass, and then filtered through a filter having a pore size of about 0.1 to 10 μm, for example. It is prepared as a composition solution.

  Examples of the solvent include glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol dimethyl ether. Diethylene glycols such as diethylene glycol ethyl methyl ether; propylene glycol monoalkyl ethers such as propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether; propylene glycol methyl ether acetate, Propylene glycol alkyl ether acetates such as pyrene glycol ethyl ether acetate, propylene glycol propyl ether acetate propylene glycol butyl ether acetate; propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate, propylene Propylene glycol alkyl ether acetates such as glycol butyl ether propionate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as methyl ethyl ketone, cyclohexanone and 4-hydroxy-4-methyl-2-pentanone; Methyl acetate and ethyl acetate , Propyl acetate, butyl acetate, ethyl 2-hydroxypropionate Esters such as methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate However, one of these solvents may be used alone, or a plurality of these solvents may be mixed and used.

  For the purpose of controlling the solubility and vapor pressure in these solvents, alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol and isopropyl alcohol, aliphatic hydrocarbons such as pentane, hexane, heptane and octane, cyclohexane You may mix with alicyclic compounds, such as a pentanone and a cyclohexane.

  In the present invention, by using the above photosensitive composition, an inorganic nanostructure based on a microphase separation structure can be formed in a photolithography pattern as follows, for example. This process will be described.

  First, a coating film is formed on the surface of a substrate such as a silicon wafer from the filtered photosensitive composition solution. At this time, as a coating method, a coating means such as a spin coating method, a dipping method, a roll coating method, or a spray method can be used.

By performing the exposure step (a) on the obtained coating film through, for example, a pattern mask, an acid or base is generated from the component (B) in a part of the coating film, and this acid or base is converted to (A) When the alkoxysilyl group in the component block copolymer and the (C) component are added, it also acts on the (C) component, and -SiOH or -M-OH ("M" is a metal atom in the (C) component) The crosslinking reaction proceeds by the subsequent heating step (b). By performing the developing step (c) here, the exposed portion is insolubilized by crosslinking, whereas the non-exposed portion is dissolved in the developer to form a pattern. Furthermore, by the step (d) of reheating at an appropriate temperature equal to or higher than the glass transition temperature (Tg) of the block copolymer, a microphase separation structure can be formed and the crosslinking reaction can be further advanced. Formation is completed. Finally, after the micro phase separation structure is formed, the organic polymer phase is selectively removed by the step (e) of heating above the temperature at which the organic matter is thermally decomposed, and the block polymer is formed in the pattern by the photolithography process. A nanostructure composed only of an inorganic material having the microphase separation structure as a template is formed. Here, as a method for removing the organic matter, instead of removing the organic matter by thermal decomposition in the above (e) baking step, the organic matter is removed by reactive ion etching (RIE) by utilizing the high etching contrast between the organic matter and the inorganic matter. May be. In this case, O ₂ gas is preferably used as the etching gas.

  In the pattern formation process of the present invention, it is preferable to perform a heat treatment (hereinafter referred to as “soft baking”) in order to remove the solvent in the film after coating by spin coating or the like. The heating conditions vary depending on the composition of the material of the present invention, the type of each additive, etc., but are preferably 30 to 200 ° C., more preferably 40 to 150 ° C., using a hot plate, oven, infrared rays, or the like. Can be heated. Hereinafter, each process in the pattern formation of the nanostructure made of an inorganic substance will be described in more detail.

In the exposure step (a), when the acid or base generated by light irradiation is added to the alkoxysilyl group in the block copolymer of the component (A) and the component (C), it is also applied to the component (C). Acts to produce -SiOH or -M-OH ("M" represents a metal atom in component (C)). Irradiation light in the exposure process includes i-line with a wavelength of 365 nm, h-line with 404 nm, g-line with 436 nm, ultraviolet light from a wide wavelength light source such as a xenon lamp, KrF excimer laser with a wavelength of 248 nm, ArF excimer laser with a wavelength of 193 nm, etc. Examples include deep ultraviolet light, visible light, and mixed lines thereof. Of these, ultraviolet light and visible light are preferred. Depending on such irradiation wavelength as ^{illumination,} it is the most reactive efficiently preferable to ^{0.1mW / cm 2 ~100mW / cm 2} . These irradiation lights can be patterned by being irradiated through a pattern mask.

  It is preferable to perform a heat treatment (post-exposure bake (PEB)) step (b) after the exposure. By this step, a condensation reaction of —SiOH or —M—OH produced by exposure occurs, and the crosslinking reaction in the block copolymer is promoted. For the heating, an apparatus similar to the soft bake can be used, and the conditions can be arbitrarily set. A preferable heating temperature is 30 to 150 ° C, and more preferably 40 to 130 ° C. If it is 30 ° C. or less, the degree of progress of the crosslinking reaction is too low, and if it is 150 ° C. or more, the crosslinking reaction proceeds too much to disturb the microphase separation structure, or the formation of the microphase separation structure itself is hindered.

  The developer in the development step (c) of the present invention can dissolve the block copolymer of component (A), the photosensitive decomposing agent of component (B), and the crosslinking agent of component (C) in the composition. If it is, it will not specifically limit. Specific examples thereof include alcohols such as isopropyl alcohol (IPA), aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), and the like. Further, a surfactant or the like may be added to the developer.

  By the reheating step (d) after development, the microphase separation structure is completely formed and the crosslinking reaction in the block copolymer is also completed. For the heating, an apparatus similar to the soft bake can be used, and the conditions can be arbitrarily set. The heating temperature may be determined according to the structure of the block copolymer used. That is, the temperature is preferably higher than the glass transition temperature Tg of the block chain constituting the block copolymer without being decomposed, and is usually 50 to 250 ° C, more preferably 80 to 200 ° C.

  The baking step (e) for removing the organic substance is preferably at least the decomposition temperature of the organic polymer, usually 300 ° C. or higher, and more preferably 450 ° C. or higher, depending on the structure of the block copolymer used. You only have to set it.

  In the present invention, in the photolithography process, the entire coating film is directly exposed without using a mask, and the reheating process (d) and the baking process (e) may be performed without performing the development process (c). it can.

  In the present invention, depending on the structure of the block copolymer to be used, the microphase separation structure is formed at a high temperature, and the cross-linking reaction proceeds excessively in the above process sequence, which may prevent the formation of the microphase separation structure. In that case, in the pattern formation step, a pattern is formed in the order of (d) a heating step at Tg or higher, (a) an exposure step, (b) a PEB step, (c) a development step, and (e) a firing step. Alternatively, after the microphase separation structure is formed, the cross-linking reaction may be performed. What is necessary is just to select the said process order suitably according to the structure of a block copolymer.

  The porous film of the inorganic substance exhibits a low dielectric constant as compared with a low dielectric constant interlayer insulating film (generally, a relative dielectric constant of 2.5 to 3.5) that has been used so far. It can be used for electronic parts such as wiring boards. Specifically, an interlayer insulating film for semiconductor elements such as LSI and DRAM, an etching stopper film, an intermediate layer of a semiconductor manufacturing process using a multilayer resist, an interlayer insulating film of a multilayer wiring board, a protective film and an insulating film for a liquid crystal display element Useful for membrane applications.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.

(Synthesis Example 1)
Poly (methyl methacrylate) -b-poly (trimethoxysilylpropyl methacrylate) (PMMA-b-PTMSPMA, where “b” is a symbol indicating that it is a block polymer) using an atom transfer radical polymerization method And was synthesized by the following procedure. Under a nitrogen atmosphere, 0.5 mmol of copper bromide, 1.0 mmol of 2,2′-dinonylbipyridyl, 1.0 mmol of paratoluenesulfonyl chloride, 150 mmol of methyl methacrylate, and 15 g of diphenyl ether were mixed and dissolved in nitrogen. Then, the reaction was carried out at 80 ° C. The reaction was carried out while confirming the polymerization rate by gas chromatography, and the reaction was stopped by quenching with liquid nitrogen. As a result of confirming the molecular weight of the obtained PMMA by GPC, it was Mn = 8300 and Mw / Mn = 1.07. Next, 0.4 mmol of polymethyl methacrylate having a terminal chlorine, 0.2 mmol of copper (I) bromide, 0.2 mmol of pentamethyldiethylenetriamine, 160 mmol of TMSPMA, and 30 ml of anisole were mixed and purged with nitrogen. After the reaction at 80 ° C., the reaction was stopped by quenching with liquid nitrogen. After purification by reprecipitation in methanol, the molecular weight of the obtained PMMA-b-PTMSPMA was confirmed by GPC. As a result, Mn = 55300 and Mw / Mn = 1.25. From this result, the molecular weight of each block was calculated to be 8300 for the PMMA block and 47000 for the PTMSPMA block, which was in good agreement with the composition ratio of both blocks determined from the peak integrated value ratio of ¹ H-NMR.

(Synthesis Example 2)
PMMA-b-PTMSPMA having a composition different from that of Synthesis Example 1 was synthesized by the following procedure using an atom transfer radical polymerization method. Under a nitrogen atmosphere, 0.2 mmol of copper bromide, 0.4 mmol of 2,2′-dinonylbipyridyl, 0.4 mmol of paratoluenesulfonyl chloride, 136 mmol of methyl methacrylate, and 13 g of diphenyl ether were mixed and dissolved oxygen with nitrogen Then, the reaction was carried out at 80 ° C. The reaction was carried out while confirming the polymerization rate by gas chromatography, and the reaction was stopped by quenching with liquid nitrogen. As a result of confirming the molecular weight of the obtained PMMA by GPC, it was Mn = 2200 and Mw / Mn = 1.11. Next, 0.4 mmol of polymethyl methacrylate having a terminal chlorine, 0.2 mmol of copper (I) bromide, 0.2 mmol of pentamethyldiethylenetriamine, 160 mmol of TMSPMA, and 30 ml of anisole were mixed and purged with nitrogen. After the reaction at 80 ° C., the reaction was stopped by quenching with liquid nitrogen. After the purification by reprecipitation into methanol, the molecular weight of the obtained PMMA-b-PTMSPMA was confirmed by GPC. As a result, Mn = 71900 and Mw / Mn = 1.28. From this result, the molecular weight of each block was calculated to be 21200 for the PMMA block and 50700 for the PTMSPMA block, which was in good agreement with the composition ratio of both blocks determined from the peak integrated value ratio of ¹ H-NMR.

(Synthesis Example 3)
Poly (ethylene glycol methyl ether) -b-poly (trimethoxysilylpropyl methacrylate) (PEG-b-PTMSPMA) was synthesized by the following procedure using an atom transfer radical polymerization method. Polyethylene glycol methacrylate (Mn: 10000) dissolved in tetrahydrofuran (THF) is reacted with 2-bromoisobutyryl bromide in the presence of triethylamine at 0 ° C. to give polyethylene glycol methyl ether-2-bromoisobutyrate (PEG) -Br) was obtained. Subsequently, the obtained PEG-Br 0.5 mmol, copper (I) bromide 0.25 mmol, pentamethyldiethylenetriamine 0.25 mmol, TMSPMA 100 mmol, and anisole 25 ml were mixed and purged with nitrogen. After the reaction at 80 ° C., the reaction was stopped by quenching with liquid nitrogen. After purification by reprecipitation into methanol, the molecular weight of the obtained PEG-b-PTMSPMA was confirmed by GPC. As a result, Mn = 32100 and Mw / Mn = 1.35. From these results, the molecular weight of each block was calculated to be 10,000 for the PEG block and 22100 for the PTMSPMA block, which was in good agreement with the composition ratio of both blocks determined from the peak integration value ratio of ¹ H-NMR.

(Synthesis Example 4)
Poly (styrene) -b-poly (vinylbenzyltrimethoxysilane) (PSt-b-PVBTMS) was synthesized by the following procedure using an atom transfer radical polymerization method. Vinylbenzyltrimethoxysilane (VBTMS) was synthesized using a Grignard reagent in accordance with the method described in Polymer Proceedings 1981, Volume 38, page 201. Under a nitrogen atmosphere, 1.7 mmol of copper (I) bromide, 1.7 mmol of pentamethyldiethylenetriamine, 1.7 mmol of 1-phenylethyl bromide, and St425 mmol were mixed, and after replacing the dissolved oxygen with nitrogen, 110 The bulk polymerization of St was performed at ° C. The reaction was carried out while confirming the polymerization rate by gas chromatography, and the reaction was stopped by quenching with liquid nitrogen. As a result of confirming the molecular weight of the obtained polystyrene by GPC, it was Mn = 16600 and Mw / Mn = 1.17. Next, 0.4 mmol of bromine-terminated polystyrene, 0.2 mmol of copper bromide, 0.2 mmol of pentamethyldiethylenetriamine, 150 mmol of VBTMS, and 30 ml of anisole were mixed and purged with nitrogen. After the reaction at 100 ° C., the reaction was stopped by quenching with liquid nitrogen. After purification by reprecipitation in methanol, the molecular weight of the obtained PSt-b-PVBTMS was confirmed by GPC. As a result, Mn = 55800 and Mw / Mn = 1.31. From these results, the molecular weight of each block was calculated to be 16600 for the PSt block and 39200 for the PVBTMS block, which agreed well with the composition ratio of both blocks determined from the peak integrated value ratio of ¹ H-NMR.

(Synthesis Example 5)
Poly (ethylene glycol methyl ether) -b-poly (trimethoxysilylpropyl methacrylate) (PEG-b-PTMSPMA) was synthesized by the following procedure using an atom transfer radical polymerization method. Polyethylene glycol methacrylate (Mn: 10000) dissolved in tetrahydrofuran (THF) is reacted with 2-bromoisobutyryl bromide in the presence of triethylamine at 0 ° C. to give polyethylene glycol methyl ether-2-bromoisobutyrate (PEG) -Br) was obtained. Subsequently, the obtained PEG-Br 0.5 mmol, copper (I) bromide 0.25 mmol, pentamethyldiethylenetriamine 0.25 mmol, TMSPMA 100 mmol, and anisole 25 ml were mixed and purged with nitrogen. After the reaction at 80 ° C., the reaction was stopped by quenching with liquid nitrogen. After purification by reprecipitation in methanol, the molecular weight of the obtained PEG-b-PTMSPMA was confirmed by GPC. As a result, Mn = 32100 and Mw / Mn = 1.35. From these results, the molecular weight of each block was calculated to be 10,000 for the PEG block and 22100 for the PTMSPMA block, and was in good agreement with the composition ratio of both blocks determined from the peak integrated value ratio of ¹ H-NMR.

(Synthesis Example 6)
Poly (lactide) -b-poly (vinylbenzyltrimethoxysilane) (PLA-b-PVBTMS) was synthesized by the following procedure using a polymerization method with a nitroxide compound. As vinylbenzyltrimethoxysilane (VBTMS), one synthesized in the same manner as in Synthesis Example 3 was used. After dissolving 0.2 mmol of 4-hydroxy TEMPO in dry toluene, 2-ethyl dissolved in 40 mmol of lactide (3,6-dimethyl-1,4-dioxane-2,5-dione) and 5 ml of dry toluene. Tin hexanoate (catalyst, 45 mg) was added and mixed. After thoroughly stirring and evaporating toluene, the deaeration was repeated several times to completely remove moisture, and the reaction receiver was evacuated. Next, polymerization of lactide was performed at 110 ° C. to obtain polylactide having TEMPO at the terminal. As a result of confirming the molecular weight of the obtained polylactide by GPC, it was Mn = 9100 and Mw / Mn = 1.11. The obtained TEMPO-terminated polylactide (0.2 mmol), VBTMS (150 mmol), and benzoyl peroxide (0.18 mmol) were mixed, degassed several times to remove moisture and oxygen, and the system was purged with nitrogen. Subsequent to the reaction at 95 ° C. for 3.5 hours, the polymerization was carried out at 125 ° C. for 60 hours and then quenched with liquid nitrogen to stop the reaction. After purification by reprecipitation in methanol, the molecular weight of the obtained PLA-b-PVBTMS was confirmed by GPC. As a result, Mn = 49500 and Mw / Mn = 1.41. From these results, the molecular weight of each block was calculated to be 9100 for the PLA block and 40400 for the PVBTMS block, and agreed well with the composition ratio of both blocks determined from the peak integrated value ratio of ¹ H-NMR.

[Example 1]
3 g of the block copolymer (PMMA-b-PTMSPMA) obtained in Synthesis Example 1 and 80 mg of triphenylsulfonium trifluoromethanesulfonate were dissolved in 60 g of PGMEA (propylene glycol monomethyl ether acetate), and the resulting solution was dissolved in 0.1 μm. The photosensitive composition 1 of this invention was obtained by filtering with a filter.

  The obtained composition was applied onto a silicon wafer by spin coating, and heated at 90 ° C. for 2 minutes on a hot plate to perform soft baking. Next, after exposing through a mask using i-line as irradiation light, it was heated at 100 ° C. for 90 seconds to perform PEB. This film was developed with isopropyl alcohol / toluene (volume ratio 1: 1), the non-exposed portion was removed, and a negative pattern was obtained. Then, the sample was placed in an oven under a nitrogen atmosphere at 180 ° C. for 3 hours. Time annealing was performed to form a microphase separation structure. Furthermore, it heated up to 550 degreeC at 10 degree-C / min, and baked as it was at 550 degreeC for 2 hours. As a result of observing the obtained film by SEM, a spherical hole having a diameter of 15 nm is vacant in a 2.0 μm L / S lithography pattern, and a spherical pattern based on a microphase separation structure is included in the lithography pattern. Was confirmed to be a porous silica membrane formed.

[Example 2]
3 g of the block copolymer (PMMA-b-PTMSPMA) obtained in Synthesis Example 2, 50 mg of triphenylsulfonium hexafluoroantimonate, and 0.6 g of tetramethoxysilane were dissolved in 80 g of ethyl cellosolve acetate. The obtained solution was filtered with a 0.1 μm filter to obtain a photosensitive composition 2 of the present invention. A pattern was formed on the obtained composition by the same steps as in Example 1. About the obtained film | membrane, similarly to Example 1, the 2.0 micrometer L / S pattern was observed by SEM. As a result, it was confirmed that the silica nanostructure had a cylinder periodic structure with a diameter of 25 nm in the lithography pattern, and a pattern based on the microphase separation structure was formed in the photolithography pattern.

[Example 3]
5 g of the block copolymer (PEG-b-PTMSPMA) obtained in Synthesis Example 3, 80 mg of triphenylsulfonium hexafluoroantimonate, and 0.2 g of tributoxyaluminum were dissolved in 100 g of PGMEA. And the photosensitive composition 3 was obtained by filtering with a 0.1 micrometer filter. A pattern was formed by the same process as in Example 1 except that the final baking step was changed from 550 ° C to 450 ° C. About the obtained film | membrane, similarly to Example 1, the 2.0 micrometer L / S pattern was observed by SEM. As a result, a silica-alumina hybrid nanostructure in which a gap of a gyroidal co-continuous structure having a diameter of 15 nm is vacant in the lithography pattern and a pattern based on a microphase separation structure is formed in the photolithography pattern. It was confirmed that there was.

[Example 4]
5 g of the block copolymer (PEG-b-PTMSPMA) obtained in Synthesis Example 3, 80 mg of triphenylsulfonium hexafluoroantimonate, and 1.0 g of tetramethoxysilane were dissolved in 90 g of PGMEA. And the photosensitive composition 4 was obtained by filtering with a 0.1 micrometer filter. A pattern was formed by the same process as in Example 3. About the obtained film | membrane, similarly to Example 1, the 2.0 micrometer L / S pattern was observed by SEM. As a result, it was confirmed that the silica nanostructure was a lithographic pattern with a 15 nm diameter gyroidal co-continuous void and a pattern based on a microphase separation structure formed in the photolithography pattern. It was done.

[Example 5]
5 g of the block copolymer (PSt-b-PVBTMS) obtained in Synthesis Example 4, 120 mg of triphenylsulfonium trifluoromethanesulfonate, and 1.0 g of tetraethoxysilane were dissolved in 100 g of PGMEA. And the photosensitive composition 5 of this invention was obtained by filtering with a 0.1 micrometer filter. A pattern was formed by the same process as in Example 1 except that the final baking step was changed from 550 ° C. to 600 ° C. About the obtained film | membrane, similarly to Example 1, the 2.0 micrometer L / S pattern was observed by SEM. As a result, it was confirmed that the silica nanostructure had a cylinder periodic structure with a diameter of 25 nm in the lithography pattern, and a pattern based on the microphase separation structure was formed in the photolithography pattern.

[Example 6]
The photosensitive composition 4 of Example 4 was applied onto a silicon wafer by spin coating, and soft-baked at 90 ° C. for 2 minutes on a hot plate. Next, the entire surface was directly exposed as i-ray irradiation light without passing through a mask, and then heated at 100 ° C. for 1 minute to perform PEB. This sample was put in an oven without performing a development step, annealed at 180 ° C. for 3 hours in a nitrogen atmosphere, heated to 550 ° C. at 10 ° C./min, and baked at 550 ° C. for 2 hours. As a result of observing the obtained film by SEM, it was confirmed that the film was a silica porous film having a gyroidal co-continuous structure having a diameter of 15 nm formed on the entire surface of the film.

  Next, the relative dielectric constant of this film was measured. For the relative dielectric constant, an Al electrode was formed on the film by vapor deposition, the capacitance of the capacitor formed by the Al electrode and the silicon wafer was measured, and the relative dielectric constant was calculated from the film thickness and the area of the Al electrode. The capacitance measurement was performed at 100 kHz using an impedance analyzer. As a result, the relative dielectric constant was as low as 2.1.

[Example 7]
In this example, a block copolymer in which a segment not containing an alkoxysilyl group is composed of a polyether polymer is used. 5 g of the block copolymer (PEG-b-PTMSPMA) obtained in Synthesis Example 5, 80 mg of triphenylsulfonium hexafluoroantimonate, and 1.0 g of tetramethoxysilane were dissolved in 90 g of PGMEA. And the photosensitive composition 5 was obtained by filtering with a 0.1 micrometer filter. A pattern was formed by the same process as in Example 4. About the obtained film | membrane, similarly to Example 1, the 2.0 micrometer L / S pattern was observed by SEM. As a result, it was confirmed that the silica nanostructure was a lithographic pattern with a 15 nm diameter gyroidal co-continuous void and a pattern based on a microphase separation structure formed in the photolithography pattern. It was done.

[Example 8]
In this example, a block copolymer in which a segment containing no alkoxysilyl group is a polyester polymer is used. 3 g of the block copolymer (PLA-b-PVBTMS) obtained in Synthesis Example 6, 90 mg of 2- (4-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, and 0.6 g of tetraethoxysilane were added to 100 g of PGMEA. Dissolved. And the photosensitive composition 6 of this invention was obtained by filtering with a 0.1 micrometer filter. A pattern was formed by the same process as in Example 1 except that the final baking step was changed from 550 ° C. to 400 ° C. About the obtained film | membrane, similarly to Example 1, the 2.0 micrometer L / S pattern was observed by SEM. As a result, a spherical void having a diameter of 15 nm was vacated in the lithography pattern, and it was confirmed that the silica nanostructure had a pattern based on a microphase separation structure formed in the photolithography pattern.

[Example 9]
The photosensitive composition 5 of Example 7 was applied onto a silicon wafer by spin coating, and soft-baked at 90 ° C. for 2 minutes on a hot plate. Next, the entire surface was directly exposed as i-ray irradiation light without passing through a mask, and then heated at 100 ° C. for 1 minute to perform PEB. This sample was put in an oven without performing a development step, annealed at 180 ° C. for 3 hours in a nitrogen atmosphere, heated to 550 ° C. at 10 ° C./min, and baked at 550 ° C. for 2 hours. As a result of observing the obtained film by SEM, it was confirmed that the film was a silica porous film having a gyroidal co-continuous structure having a diameter of 15 nm formed on the entire surface of the film.

  Next, the relative dielectric constant of this film was measured. For the relative dielectric constant, an Al electrode was formed on the film by vapor deposition, the capacitance of the capacitor formed by the Al electrode and the silicon wafer was measured, and the relative dielectric constant was calculated from the film thickness and the area of the Al electrode. The capacitance measurement was performed at 100 kHz using an impedance analyzer. As a result, the relative dielectric constant was as low as 2.1.

  Since the porous inorganic nanostructure of the present invention can be suitably used as a low dielectric constant insulating film such as a semiconductor device or a multilayer wiring board, its utility value is extremely high.

Claims (8)

(A) a block copolymer including a segment having a monomer containing an alkoxysilyl group as a repeating unit;
(B) a photosensitive decomposing agent,
A photosensitive composition, wherein the block polymer has a molecular weight distribution index (Mw / Mn) of 1.8 or less.   (C) The photosensitive composition of Claim 1 containing the compound which can bridge | crosslink said (A) in presence of an acid or a base.   The photosensitive composition according to claim 1, wherein the photosensitive decomposing agent is either a photosensitive acid generator or a photosensitive base generator. In the block copolymer containing a segment comprising the monomer containing the alkoxysilyl group as a repeating unit,
2. The photosensitive composition according to claim 1, wherein the main chain of the segment not containing an alkoxysilyl group contains an ester bond. In the block copolymer containing a segment comprising the monomer containing the alkoxysilyl group as a repeating unit,
The photosensitive composition according to claim 1, wherein the main chain of the segment not containing an alkoxysilyl group contains an ether bond. A method for producing a structure including a microphase separation structure,
It includes the following steps.
(1) (A) a block copolymer including a segment having a repeating unit of an alkoxysilyl group-containing monomer having a molecular weight distribution index (Mw / Mn) of 1.8 or less, and (B) photosensitive decomposition A step of exposing a film comprising a composition containing an agent (2) a step of developing the film after the exposure step (3) a step of heating the film after the exposure step   The method of manufacturing a structure according to claim 6, wherein the step (2) is performed after the step (3).   The method for producing a structure according to claim 6, further comprising a step of heating at a temperature equal to or higher than a glass transition temperature of the block copolymer after the steps (1) to (3).