JPWO2008081895A1 - Synthesis method of hyperbranched polymer - Google Patents

Abstract

In order to synthesize a core-shell hyperbranched polymer that can be used as a polymer material for nanofabrication centering on optical lithography, when synthesizing a core-shell hyperbranched polymer via living radical polymerization of monomers, A polymer synthesized by living radical polymerization using an initiator monomer for initiating living radical polymerization was used as a core part, and a shell part containing an acid-decomposable group and an acid group was formed at the end of the core part. In addition, when synthesizing a star polymer via living radical polymerization of the monomer, a polymer synthesized by living radical polymerization is used as an arm part, and a compound having two or more vinyl groups is added during or after polymerization of the arm part. By doing so, the arm parts are coupled to each other, and a core part forming step of forming the core part is included.

Description

  The present invention relates to a method for synthesizing a hyperbranched polymer.

  In recent years, optical lithography, which is regarded as promising as a microfabrication technology, has advanced design rule miniaturization due to the shortening of the wavelength of the light source, thereby realizing high integration of VLSI. EUV lithography is considered promising for design rules of 32 nm or less.

  For the resist composition, development of a base polymer having a chemical structure transparent to each light source is in progress. For example, in a KrF excimer laser beam (wavelength 248 nm), a polymer having a novolac-type polyphenol as a basic skeleton (see, for example, Patent Document 1 below), and in an ArF excimer laser beam (wavelength 193 nm), a poly (meth) acrylate ester (for example, , Refer to Patent Document 2 below), or F2 excimer laser light (wavelength 157 nm), each of which proposes a resist composition containing a polymer into which a fluorine atom (perfluoro structure) is introduced (for example, refer to Patent Document 3 below). These polymers are based on a linear structure.

  However, when these linear polymers are applied to the formation of ultrafine patterns having a thickness of 32 nm or less, the unevenness of the pattern side wall with the line edge roughness as an index has become a problem. Franco Cerrina, Vac. Sci. Tech. In B, 19, 2890 (2001), conventional resists mainly composed of PMMA (polymethyl methacrylate) and PHS (polyhydroxystyrene) are exposed to an electron beam or extreme ultraviolet light (EUV: 13.5 nm). It has been pointed out that controlling the surface smoothness at the nano level is a problem in order to form ultrafine patterns.

  Toru Yamaguchi, Jpn. J. et al. Appl. Phys. , 38, 7114 (1999), the unevenness of the pattern side wall is attributed to a polymer aggregate (cluster) constituting the resist. It is said that the decrease in line edge roughness due to clusters can be reduced by using a low molecular weight monodisperse polymer (see, for example, Patent Document 4 below). However, when a low molecular weight polymer is used, the Tg of the polymer decreases. However, since baking with heat becomes difficult, it lacks practicality.

  On the other hand, a branched polymer is known as an example in which line edge roughness is improved as compared with a linear molecule (Alexander R. Trimble, Processeds of SPIE, 3999, 1198, (2000)). However, in terms of adhesion to the substrate and sensitivity, those satisfying the requirements associated with miniaturization of design rules have not been achieved.

  From such a viewpoint, attempts have been made in recent years to use hyperbranched polymers as resist materials. Conventionally, hyperbranched polymers having a highly branched (branched) structure as a core and having an acid group (for example, carboxylic acid) and an acid-decomposable group (for example, a carboxylic acid ester) at the molecular ends are found in linear polymers. Large molecules that cause surface roughness on the pattern sidewall (see, for example, Patent Document 5 below) as a result of less entanglement between molecules and less swelling by the solvent compared to the molecular structure that crosslinks the main chain. Aggregate formation has been reported to be suppressed.

  In addition, the hyperbranched polymer usually takes a spherical form. However, when an acid-decomposable group is present on the spherical polymer surface, in photolithography, a decomposition reaction occurs due to the action of an acid generated from the photoacid generator at the exposed portion, and hydrophilicity occurs. As a result of the formation of groups, it has been reported that a spherical micelle-like structure in which a large number of hydrophilic groups exist on the outer periphery of the polymer molecule can be taken. As a result, it was reported that the polymer was efficiently dissolved in an alkaline aqueous solution and removed together with the alkaline solution, so that a fine pattern could be formed and it could be suitably used as a base resin for a resist material. Has been. Furthermore, it has been clarified that the alkali solubility after exposure, that is, the improvement in sensitivity, can be achieved by coexistence at a certain ratio of the carboxylic acid ester group and the carboxylic acid group which are acid-decomposable groups. ing.

Japanese Patent Laid-Open No. 2004-231858 JP 2004-359929 A JP 2005-91428 A JP-A-6-266099 International Publication No. 2005/061566 Pamphlet

  As an example of synthesizing a resist polymer containing an acid-decomposable group and an acid group on the surface of the hyperbranched polymer, an example using atom transfer radical polymerization is known (see, for example, WO 2005/061566). In atom transfer radical polymerization (ATRP method), a reversible transfer reaction of an atom or group from a dormant species (RX) to a transition metal catalyst, thereby a radical that initiates polymerization, and an oxidation state advance by one. However, since it is based on a reaction in which a metal halide is formed, there has been a problem that a large amount of the metal halide must be removed from the reaction system after polymerization. In the ATRP method, when an acid-decomposable group and an acid group are to be introduced at the same time, a carboxylic acid group as an acid group is coordinated with copper as a catalyst, reducing the activity of the catalyst. First, an acid-decomposable group was introduced, and then a part of the acid-decomposable group was converted into an acid group by acid decomposition, and a corresponding resist polymer had to be synthesized.

  In high-performance photoresist polymers, the amount of metal impurities must be significantly reduced, especially to avoid contamination during plasma processing and adverse effects on semiconductor electrical properties due to metal impurities remaining in the pattern. Therefore, aggressive metal addition as a catalyst is not desirable.

  The present invention has been made in view of the above circumstances, and can be used as a polymer material for nanofabrication centered on photolithography, a core-shell hyperbranched polymer with improved surface smoothness and alkali solubility, It is an object of the present invention to provide a method for producing the core-shell hyperbranched polymer and a resist composition containing the core-shell hyperbranched polymer.

  In order to solve the above-described problems and achieve the object, a method for synthesizing a core-shell hyperbranched polymer according to the present invention is a method for synthesizing a core-shell hyperbranched polymer by synthesizing a core-shell hyperbranched polymer through living radical polymerization of monomers. A polymerization step in which the living radical polymerization is performed using an initiator monomer for initiating the living radical polymerization, and a polymer synthesized by the living radical polymerization is used as a core portion, and acid decomposition is performed at the end of the core portion. And a shell part forming step of forming a shell part containing a sex group and an acid group.

  Moreover, the said polymerization process in the synthesis | combining method of the core-shell hyperbranched polymer concerning this invention performs the said living radical polymerization according to the radical polymerization method which uses a nitroxyl radical as a key intermediate body.

  The method for synthesizing a star polymer according to the present invention is a method for synthesizing a star polymer through living radical polymerization of a monomer, wherein the polymer synthesized by the living radical polymerization is used as an arm part, and the arm part is being polymerized. Alternatively, the method includes a core part forming step of coupling the arm parts to form a core part by adding a compound having two or more vinyl groups after polymerization.

  The star polymer synthesis method according to the present invention is characterized in that the arm is a polymer synthesized by the living radical polymerization performed according to the radical polymerization method using a nitroxyl radical as a key intermediate.

  According to the present invention, the core-shell hyperbranched polymer for resist can be synthesized. Further, since living radical polymerization can be performed without using a metal catalyst, the reaction system is uniform and stable production is possible. Furthermore, since an acid-decomposable group and an acid group can be simultaneously introduced into the shell portion, the process can be simplified. Moreover, according to the radical polymerization method using the nitroxyl radical of the present invention as a key intermediate, a star polymer which is a kind of core-shell hyperbranched polymer can also be synthesized.

  The core-shell hyperbranched polymer according to the present invention is characterized by being synthesized according to the above-described method for synthesizing a core-shell hyperbranched polymer.

  According to this invention, the reaction system is uniform and a stable core-shell hyperbranched polymer can be obtained.

  A semiconductor integrated circuit according to the present invention is characterized in that a pattern is formed by the resist composition described above.

  According to the present invention, it is possible to obtain a fine semiconductor integrated circuit having stable performance and corresponding to an electron beam, deep ultraviolet (DUV), and extreme ultraviolet (EUV) light source.

  A method for manufacturing a semiconductor integrated circuit according to the present invention includes a step of forming a pattern using the resist composition.

  According to the present invention, it is possible to manufacture a fine semiconductor integrated circuit having stable performance and corresponding to an electron beam, deep ultraviolet (DUV), and extreme ultraviolet (EUV) light source.

  The core-shell hyperbranched polymer of the present invention is a general term for two types of polymers synthesized roughly by two types of radical polymerization methods using a nitroxyl radical as a key intermediate. First, a core shell-type hyperbranch is formed by using a polymer synthesized by the living radical polymerization as a core part and forming a shell part containing an acid-decomposable group and an acid group at the end of the core part. A method of synthesizing a polymer. Second, the polymer synthesized by the living radical polymerization is used as an arm part, and the arm part is coupled to each other by adding a compound having two or more vinyl groups during polymerization or after polymerization. This is a method of synthesizing a star polymer by forming a core part.

  Exemplary embodiments of a method for synthesizing a core-shell hyperbranched polymer according to the present invention will be described below in detail with reference to the accompanying drawings.

(Substance used for the synthesis of core-shell hyperbranched polymer)
First, materials used for the synthesis of the core-shell hyperbranched polymer of the embodiment will be described. In the synthesis of the core-shell hyperbranched polymer, an alkoxyamine having a vinyl group capable of radical polymerization in the molecule, a monomer, a polymerization initiator, and a solvent are used.

(Alkoxyamine having a vinyl group capable of radical polymerization in the molecule)
The alkoxyamine used is not particularly limited. For example, 2- (benzoyloxy) -1- (2 ′, 2 ′, 6 ′, which can be synthesized by the method described in JP-A-2000-095744. 6'-tetramethyl-1'-piperidinyloxy) -1- (4'-vinylphenyl) ethane, 2- (isopropyloxycarbonyloxy) -1- (2 ', 2', 6 ', 6'- Tetramethyl-1'-piperidinyloxy) -1- (4'-vinylphenyl) ethane, 2- (n-propyloxycarbonyloxy) -1- (2 ', 2', 6 ', 6'-tetra Methyl-1′-piperidinyloxy) -1- (4′-vinylphenyl) ethane, 2- (2-ethylhexyloxycarbonyloxy) -1- (2 ′, 2 ′, 6 ′, 6′-tetramethyl -1′-piperidinyloxy) -1- (4′-vinylpheny ) Ethane, 2- (4′-t-butylcyclohexyloxycarbonyloxy) -1- (2 ′, 2 ′, 6 ′, 6′-tetramethyl-1′-piperidinyloxy) -1- (4 ′ -Vinylphenyl) ethane, 2- (isopropyloxycarbonyloxy) -1- (4'-benzoyloxy-2 ', 2', 6 ', 6'-tetramethyl-1'-piperidinyloxy) -1- (4′-vinylphenyl) ethane, 2- (isopropyloxycarbonyloxy) -1- (4′-acetoxy-2 ′, 2 ′, 6 ′, 6′-tetramethyl-1′-piperidinyloxy)- 1- (4′-vinylphenyl) ethane, 2- (isopropyloxycarbonyloxy) -1- (di-t-butylnitroxyl) -1- (4′-vinylphenyl) ethane, 2- (isopropyloxycarbonyloxy) ) -1- (4 ' -Hydroxy-2 ', 2', 6 ', 6'-tetramethyl-1'-piperidinyloxy) -1- (4'-vinylphenyl) ethane, 2-benzoyloxy-1 (2,2,6, It is preferable to use 6-tetramethyl-1-piperidinyloxy) -1- (4-vinylphenyl) ethane or the like.

<Monomer constituting the core>
Here, the monomer which comprises a core part among the monomers used for the synthesis | combination of a core-shell hyperbranched polymer is demonstrated. The core part of the core-shell hyperbranched polymer (hereinafter referred to as hyperbranched core polymer) constitutes the nucleus of the hyperbranched polymer molecule. The core part of the core-shell hyperbranched polymer can contain other monomers in addition to the alkoxyamine having a radically polymerizable vinyl group in the molecule. The other monomer is not particularly limited as long as it is a monomer capable of radical polymerization, and can be appropriately selected according to the purpose.

  Examples of other monomers capable of radical polymerization include (meth) acrylic acid and (meth) acrylic acid esters, vinyl benzoic acid, vinyl benzoic acid esters, styrenes, allyl compounds, vinyl ethers, and vinyl esters. And a compound having a radical polymerizable unsaturated bond selected from the above.

  Specific examples of (meth) acrylic acid esters mentioned as other monomers capable of radical polymerization include, for example, tert-butyl acrylate, 2-methylbutyl acrylate, 2-methylpentyl acrylate, and acrylic acid. 2-ethylbutyl, 3-methylpentyl acrylate, 2-methylhexyl acrylate, 3-methylhexyl acrylate, triethylcarbyl acrylate, 1-methyl-1-cyclopentyl acrylate, 1-ethyl-1-cyclopentyl acrylate 1-methyl-1-cyclohexyl acrylate, 1-ethyl-1-cyclohexyl acrylate, 1-methylnorbornyl acrylate, 1-ethylnorbornyl acrylate, 2-methyl-2-adamantyl acrylate, acrylic acid 2 -Ethyl-2-adamantyl, acrylic acid 3 Hydroxy-1-adamantyl, tetrahydrofuranyl acrylate, tetrahydropyranyl acrylate, 1-methoxyethyl acrylate, 1-ethoxyethyl acrylate, 1-n-propoxyethyl acrylate, 1-isopropoxyethyl acrylate, acrylic acid n-butoxyethyl, 1-isobutoxyethyl acrylate, 1-sec-butoxyethyl acrylate, 1-tert-butoxyethyl acrylate, 1-tert-amyloxyethyl acrylate, 1-ethoxy-n-propyl acrylate 1-cyclohexyloxyethyl acrylate, methoxypropyl acrylate, ethoxypropyl acrylate, 1-methoxy-1-methyl-ethyl acrylate, 1-ethoxy-1-methyl-ethyl acrylate, trimethylsilyl acrylate, Triethylsilyl phosphate, dimethyl-tert-butylsilyl acrylate, α- (acryloyl) oxy-γ-butyrolactone, β- (acryloyl) oxy-γ-butyrolactone, γ- (acryloyl) oxy-γ-butyrolactone, α-methyl- α- (Acroyl) oxy-γ-butyrolactone, β-methyl-β- (acryloyl) oxy-γ-butyrolactone, γ-methyl-γ- (acryloyl) oxy-γ-butyrolactone, α-ethyl-α- (acryloyl) Oxy-γ-butyrolactone, β-ethyl-β- (acryloyl) oxy-γ-butyrolactone, γ-ethyl-γ- (acryloyl) oxy-γ-butyrolactone, α- (acryloyl) oxy-δ-valerolactone, β- (Acroyl) oxy-δ-valerolactone, γ- (acryloyl) oxy-δ-valerolacto , Δ- (acroyl) oxy-δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-methyl-β- (acroyl) oxy-δ-valerolactone, γ -Methyl-γ- (acryloyl) oxy-δ-valerolactone, δ-methyl-δ- (acryloyl) oxy-δ-valerolactone, α-ethyl-α- (acryloyl) oxy-δ-valerolactone, β-ethyl -Β- (Acroyl) oxy-δ-valerolactone, γ-ethyl-γ- (acryloyl) oxy-δ-valerolactone, δ-ethyl-δ- (acryloyl) oxy-δ-valerolactone, 1-methyl acrylate Cyclohexyl, adamantyl acrylate, 2- (2-methyl) adamantyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, a 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane acrylate, glycidyl acrylate, benzyl acrylate, phenyl acrylate, naphthyl acrylate, tert-butyl methacrylate, 2-methylbutyl methacrylate 2-methylpentyl methacrylate, 2-ethylbutyl methacrylate, 3-methylpentyl methacrylate, 2-methylhexyl methacrylate, 3-methylhexyl methacrylate, triethylcarbyl methacrylate, 1-methyl-1-cyclopentyl methacrylate 1-ethyl-1-cyclopentyl methacrylate, 1-methyl-1-cyclohexyl methacrylate, 1-ethyl-1-cyclohexyl methacrylate, 1-methylnorbornyl methacrylate, methacrylic acid -Ethyl norbornyl, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, tetrahydrofuranyl methacrylate, tetrahydropyranyl methacrylate, 1-methacrylic acid 1- Methoxyethyl, 1-ethoxyethyl methacrylate, 1-n-propoxyethyl methacrylate, 1-isopropoxyethyl methacrylate, n-butoxyethyl methacrylate, 1-isobutoxyethyl methacrylate, 1-sec-butoxyethyl methacrylate 1-tert-butoxyethyl methacrylate, 1-tert-amyloxyethyl methacrylate, 1-ethoxy-n-propyl methacrylate, 1-cyclohexyloxyethyl methacrylate, methoxypropyl methacrylate, Ethoxypropyl tacrylate, 1-methoxy-1-methyl-ethyl methacrylate, 1-ethoxy-1-methyl-ethyl methacrylate, trimethylsilyl methacrylate, triethylsilyl methacrylate, dimethyl-tert-butylsilyl methacrylate, α- (methacryloyl) ) Oxy-γ-butyrolactone, β- (methacryloyl) oxy-γ-butyrolactone, γ- (methacryloyl) oxy-γ-butyrolactone, α-methyl-α- (methacryloyl) oxy-γ-butyrolactone, β-methyl-β- (Methacroyl) oxy-γ-butyrolactone, γ-methyl-γ- (methacloyl) oxy-γ-butyrolactone, α-ethyl-α- (methacloyl) oxy-γ-butyrolactone, β-ethyl-β- (methacloyl) oxy- γ-butyrolactone, γ-ethyl γ- (methacryloyl) oxy-γ-butyrolactone, α- (methacryloyl) oxy-δ-valerolactone, β- (methacryloyl) oxy-δ-valerolactone, γ- (methacryloyl) oxy-δ-valerolactone, δ- ( Methacryloyl) oxy-δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-methyl-β- (methacryloyl) oxy-δ-valerolactone, γ-methyl-γ- (Methacloyl) oxy-δ-valerolactone, δ-methyl-δ- (methacloyl) oxy-δ-valerolactone, α-ethyl-α- (methacloyl) oxy-δ-valerolactone, β-ethyl-β- (methacloyl) ) Oxy-δ-valerolactone, γ-ethyl-γ- (methacloyl) oxy-δ-valerolactone, δ-ethyl-δ- ( Tacroyl) oxy-δ-valerolactone, 1-methylcyclohexyl methacrylate, adamantyl methacrylate, 2- (2-methyl) adamantyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2,2-dimethylhydroxy methacrylate Examples include propyl, 5-hydroxypentyl methacrylate, trimethylolpropane methacrylate, glycidyl methacrylate, benzyl methacrylate, phenyl methacrylate, naphthyl methacrylate, and the like.

  Specific examples of the vinyl benzoate esters mentioned as other monomers capable of radical polymerization include, for example, tert-butyl vinyl benzoate, 2-methylbutyl vinyl benzoate, 2-methylpentyl vinyl benzoate, and vinyl. 2-ethylbutyl benzoate, 3-methylpentyl vinylbenzoate, 2-methylhexyl vinylbenzoate, 3-methylhexyl vinylbenzoate, triethylcarbyl vinylbenzoate, 1-methyl-1-cyclopentyl vinylbenzoate, vinylbenzoate 1-ethyl-1-cyclopentyl acid, 1-methyl-1-cyclohexyl vinyl benzoate, 1-ethyl-1-cyclohexyl vinyl benzoate, 1-methylnorbornyl vinyl benzoate, 1-ethylnorbornyl vinyl benzoate, vinyl 2-methyl-2-adamanche benzoate , 2-ethyl-2-adamantyl vinyl benzoate, 3-hydroxy-1-adamantyl vinyl benzoate, tetrahydrofuranyl vinyl benzoate, tetrahydropyranyl vinyl benzoate, 1-methoxyethyl vinyl benzoate, 1-ethoxy vinyl benzoate Ethyl, 1-n-propoxyethyl vinylbenzoate, 1-isopropoxyethyl vinylbenzoate, n-butoxyethyl vinylbenzoate, 1-isobutoxyethyl vinylbenzoate, 1-sec-butoxyethyl vinylbenzoate, vinylbenzoate 1-tert-butoxyethyl acid, 1-tert-amyloxyethyl vinylbenzoate, 1-ethoxy-n-propyl vinylbenzoate, 1-cyclohexyloxyethyl vinylbenzoate, methoxypropyl vinylbenzoate, ethoxypropionate vinylbenzoate 1-methoxy-1-methyl-ethyl vinylbenzoate, 1-ethoxy-1-methyl-ethyl vinylbenzoate, trimethylsilyl vinylbenzoate, triethylsilyl vinylbenzoate, dimethyl-tert-butylsilyl vinylbenzoate, α- ( 4-vinylbenzoyl) oxy-γ-butyrolactone, β- (4-vinylbenzoyl) oxy-γ-butyrolactone, γ- (4-vinylbenzoyl) oxy-γ-butyrolactone, α-methyl-α- (4-vinylbenzoyl) ) Oxy-γ-butyrolactone, β-methyl-β- (4-vinylbenzoyl) oxy-γ-butyrolactone, γ-methyl-γ- (4-vinylbenzoyl) oxy-γ-butyrolactone, α-ethyl-α- ( 4-vinylbenzoyl) oxy-γ-butyrolactone, β-ethyl-β- (4-vinyl Nzoyl) oxy-γ-butyrolactone, γ-ethyl-γ- (4-vinylbenzoyl) oxy-γ-butyrolactone, α- (4-vinylbenzoyl) oxy-δ-valerolactone, β- (4-vinylbenzoyl) oxy -Δ-valerolactone, γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ- (4-vinylbenzoyl) oxy-δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy- δ-valerolactone, β-methyl-β- (4-vinylbenzoyl) oxy-δ-valerolactone, γ-methyl-γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ-methyl-δ- ( 4-vinylbenzoyl) oxy-δ-valerolactone, α-ethyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-ethyl-β (4-vinylbenzoyl) oxy-δ-valerolactone, γ-ethyl-γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ-ethyl-δ- (4-vinylbenzoyl) oxy-δ-valerolactone 1-methylcyclohexyl vinyl benzoate, adamantyl vinyl benzoate, 2- (2-methyl) adamantyl vinyl benzoate, chloroethyl vinyl benzoate, 2-hydroxyethyl vinyl benzoate, 2,2-dimethylhydroxypropyl vinyl benzoate, Examples thereof include 5-hydroxypentyl vinylbenzoate, trimethylolpropane vinylbenzoate, glycidyl vinylbenzoate, benzyl vinylbenzoate, phenyl vinylbenzoate, and naphthyl vinylbenzoate.

  Specific examples of styrenes listed as other monomers capable of radical polymerization include, for example, styrene, benzyl styrene, trifluoromethyl styrene, acetoxy styrene, chlorostyrene, dichlorostyrene, trichlorostyrene, and tetrachlorostyrene. , Pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, vinylnaphthalene, etc. It is done.

  Specific examples of allyl compounds listed as other monomers capable of radical polymerization include, for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate. , Allyl acetoacetate, allyl lactate, allyloxyethanol and the like.

  Specific examples of vinyl ethers listed as other monomers capable of radical polymerization include, for example, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1- Methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, vinyl phenyl ether, vinyl Tril ether, vinyl chlorfe Ether, vinyl 2,4-dichlorophenyl ether, vinyl naphthyl ether, and vinyl anthranyl ether.

  Specific examples of vinyl esters listed as other monomers capable of radical polymerization include, for example, vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, Examples include vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinylphenylacetate, vinylacetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate and the like.

  Specific examples of the monomer used for the synthesis of the hyperbranched core polymer include (meth) acrylic acid, tert-butyl (meth) acrylate, 4-vinylbenzoic acid, tert-butyl 4-vinylbenzoate, and styrene. , Benzylstyrene, chlorostyrene, and vinylnaphthalene are preferred.

  The ratio of the repeating unit derived from the monomer constituting the hyperbranched core polymer is preferably 10 to 90 mol% with respect to all repeating units constituting the core-shell hyperbranched polymer. -80 mol% is more preferable, and it is still more preferable that it is contained in the amount of 10-60 mol%.

  By adjusting the amount of the repeating unit derived from the monomer constituting the hyperbranched core polymer to be within the above range, for example, when the core-shell hyperbranched polymer is used as a resist composition, Appropriate hydrophobicity can be imparted to the developer of the polymer. As a result, using a resist composition containing a core-shell hyperbranched polymer with a hyperbranched core polymer as a core part, for example, when performing microfabrication of semiconductor integrated circuits, flat panel displays, printed wiring boards, etc., unexposed Since dissolution of a part can be suppressed, it is preferable.

  The hyperbranched core polymer may be composed only of an alkoxyamine having a radically polymerizable vinyl group in the molecule, or may be radically polymerized with an alkoxyamine having a radically polymerizable vinyl group in the molecule. It may be comprised from the monomer of.

  When the hyperbranched core polymer is a copolymer of an alkoxyamine having other radical polymerizable vinyl groups in the molecule and other monomers, the radical polymerization is performed on all repeating units constituting the hyperbranched core polymer. The proportion of alkoxyamine having a possible vinyl group in the molecule is preferably 10 to 99 mol%, more preferably 20 to 99 mol%, and even more preferably 30 to 99 mol%. . In the hyperbranched core polymer, if the amount of the alkoxyamine having a radically polymerizable vinyl group in the molecule is within the above range, the hyperbranched core polymer takes a spherical form, which is advantageous for suppressing entanglement between molecules. In addition, it is preferable because functions such as substrate adhesion and increase in glass transition temperature are provided. In addition, the amount of the alkoxyamine having the above-mentioned radically polymerizable vinyl group in the core and the other monomer can be adjusted by the charge amount ratio at the time of polymerization according to the purpose.

<Monomer constituting the shell part>
Next, of the monomers used for the synthesis of the core-shell hyperbranched polymer, the monomer that constitutes the shell portion will be described. The shell part of the core-shell hyperbranched polymer constitutes the end of the hyperbranched polymer molecule. The shell part of the core-shell hyperbranched polymer includes at least one of repeating units represented by the following formulas (II) and (III).

  The repeating unit represented by the following formulas (II) and (III) generates an acid by the action of an organic acid such as acetic acid, maleic acid or benzoic acid or an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, preferably by light energy. It contains an acid-decomposable group that decomposes by the action of a photoacid generator. When introducing acid-decomposable groups into the shell at the same time, the ratio of acid-decomposable groups to acid groups in the shell is optimal depending on the ratio of repeating units derived from other monomers that constitute the core-shell hyperbranched polymer. However, it is preferably 95/5 to 5/95. The acid-decomposable group is preferably decomposed into a hydrophilic group.

R ¹ in the above formula (II) and R ⁴ in the above formula (III) represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Among these, as R ¹ in the above formula (II) and R ⁴ in the above formula (III), a hydrogen atom and a methyl group are preferable. As R ¹ in the above formula (II) and R ⁴ in the above formula (III), a hydrogen atom is more preferable.

R ² in the above formula (II) represents a hydrogen atom, an alkyl group, or an aryl group. The alkyl group for R ² in the above formula (II) preferably has, for example, 1 to 30 carbon atoms. The more preferable carbon number of the alkyl group in R < ² > in said formula (II) is 1-20. The more preferable carbon number of the alkyl group in R ² in the above formula (II) is 1-10. The alkyl group has a linear, branched or cyclic structure. Specifically, examples of the alkyl group for R ² in the above formula (II) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, and a cyclohexyl group. It is done.

The aryl group for R ² in the above formula (II) preferably has, for example, 6 to 30 carbon atoms. The more preferable carbon number of the aryl group in R ² in the above formula (II) is 6-20. The more preferable carbon number of the aryl group in R ² in the above formula (II) is 6-10. Specifically, examples of the aryl group in R ² in the above formula (II) include a phenyl group, a 4-methylphenyl group, and a naphthyl group. Among these, a hydrogen atom, a methyl group, an ethyl group, a phenyl group, etc. are mentioned. As R ² in the above formula (II), one of the most preferable groups is a hydrogen atom.

R ³ in the above formula (II) and R ⁵ in the above formula (III) represent a hydrogen atom, an alkyl group, a trialkylsilyl group, an oxoalkyl group, or a group represented by the following formula (i). . The alkyl group in R ³ in the above formula (II) and R ⁵ in the above formula (III) preferably has 1 to 40 carbon atoms. The more preferable carbon number of the alkyl group in R ³ in the above formula (II) and R ⁵ in the above formula (III) is 1-30.

The more preferable carbon number of the alkyl group in R ³ in the above formula (II) and R ⁵ in the above formula (III) is 1-20. The alkyl group in R ³ in the above formula (II) and R ⁵ in the above formula (III) has a linear, branched or cyclic structure. As R ³ in the formula (II) and R ⁵ in the formula (III), a branched alkyl group having 1 to 20 carbon atoms is more preferable.

The preferable carbon number of each alkyl group in R ³ in the above formula (II) and R ⁵ in the above formula (III) is 1-6, and more preferable carbon number is 1-4. The carbon number of the alkyl group of the oxoalkyl group in R ³ in the above formula (II) and R ⁵ in the above formula (III) is 4 to 20, and more preferably 4 to 10.

R ⁶ in the above formula (i) represents a hydrogen atom or an alkyl group. The alkyl group in R ⁶ of the group represented by the following formula (i) has a linear, branched, or cyclic structure. It is preferable that carbon number of the alkyl group in R < ⁶ > of group represented by following formula (i) is 1-10. The more preferable carbon number of the alkyl group in R < ⁶ > of group represented by following formula (i) is 1-8, and a more preferable carbon number is 1-6.

R ⁷ and R ⁸ in the above formula (i) are a hydrogen atom or an alkyl group. The hydrogen atom or alkyl group in R ⁷ and R ⁸ in the above formula (i) may be independent from each other or may form a ring together. The alkyl group in R ⁷ and R ⁸ in the above formula (i) has a linear, branched or cyclic structure. It is preferable that carbon number of the alkyl group in R < ⁷ > and R < ⁸ > in the said formula (i) is 1-10. The more preferable carbon number of the alkyl group in R ⁷ and R ⁸ in the above formula (i) is 1-8. The more preferable carbon number of the alkyl group in R ⁷ and R ⁸ in the above formula (i) is 1-6. R ⁷ and R ⁸ in the above formula (i) are preferably a branched alkyl group having 1 to 20 carbon atoms.

  Examples of the group represented by the above formula (i) include 1-methoxyethyl group, 1-ethoxyethyl group, 1-n-propoxyethyl group, 1-isopropoxyethyl group, 1-n-butoxyethyl group, 1-iso Butoxyethyl group, 1-sec-butoxyethyl group, 1-tert-butoxyethyl group, 1-tert-amyloxyethyl group, 1-ethoxy-n-propyl group, 1-cyclohexyloxyethyl group, methoxypropyl group, ethoxy Linear or branched acetal groups such as propyl group, 1-methoxy-1-methyl-ethyl group, 1-ethoxy-1-methyl-ethyl group; cyclic acetal groups such as tetrahydrofuranyl group, tetrahydropyranyl group, etc. Is mentioned. As the group represented by the above formula (i), among the above-mentioned groups, an ethoxyethyl group, a butoxyethyl group, an ethoxypropyl group, and a tetrahydropyranyl group are particularly preferable.

In R ³ in the above formula (II) and R ⁵ in the above formula (III), as the linear, branched or cyclic alkyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, tert-butyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, triethylcarbyl group, 1-ethylnorbornyl group, 1-methylcyclohexyl group, adamantyl group, 2- (2-methyl) adamantyl group, tert-amyl group Etc. Of these, a tert-butyl group is particularly preferred.

In R ³ in the above formula (II) and R ⁵ in the above formula (III), the trialkylsilyl group includes carbon atoms of each alkyl group such as trimethylsilyl group, triethylsilyl group, dimethyl-tert-butylsilyl group, etc. 1-6 are mentioned. Examples of the oxoalkyl group include a 3-oxocyclohexyl group.

  Examples of the monomer that gives the repeating unit represented by the above formula (II) include vinyl benzoic acid, tert-butyl vinyl benzoate, 2-methylbutyl vinyl benzoate, 2-methylpentyl vinyl benzoate, 2-ethylbutyl vinyl benzoate, vinyl 3-methylpentyl benzoate, 2-methylhexyl vinylbenzoate, 3-methylhexyl vinylbenzoate, triethylcarbyl vinylbenzoate, 1-methyl-1-cyclopentyl vinylbenzoate, 1-ethyl-1-vinylbenzoate Cyclopentyl, 1-methyl-1-cyclohexyl vinylbenzoate, 1-ethyl-1-cyclohexyl vinylbenzoate, 1-methylnorbornyl vinylbenzoate, 1-ethylnorbornyl vinylbenzoate, 2-methyl-2 vinylbenzoate -Adamantyl, vinyl benzoate 2- Tyl-2-adamantyl, 3-hydroxy-1-adamantyl vinylbenzoate, tetrahydrofuranyl vinylbenzoate, tetrahydropyranyl vinylbenzoate, 1-methoxyethyl vinylbenzoate, 1-ethoxyethyl vinylbenzoate, vinylbenzoic acid 1 -N-propoxyethyl, 1-isopropoxyethyl vinylbenzoate, n-butoxyethyl vinylbenzoate, 1-isobutoxyethyl vinylbenzoate, 1-sec-butoxyethyl vinylbenzoate, 1-tert-butoxy vinylbenzoate Ethyl, 1-tert-amyloxyethyl vinyl benzoate, 1-ethoxy-n-propyl vinyl benzoate, 1-cyclohexyloxyethyl vinyl benzoate, methoxypropyl vinyl benzoate, ethoxypropyl vinyl benzoate, 1-vinyl benzoate 1- Toxi-1-methyl-ethyl, 1-ethoxy-1-methyl-ethyl vinylbenzoate, trimethylsilyl vinylbenzoate, triethylsilyl vinylbenzoate, dimethyl-tert-butylsilyl vinylbenzoate, α- (4-vinylbenzoyl) oxy -Γ-butyrolactone, β- (4-vinylbenzoyl) oxy-γ-butyrolactone, γ- (4-vinylbenzoyl) oxy-γ-butyrolactone, α-methyl-α- (4-vinylbenzoyl) oxy-γ-butyrolactone , Β-methyl-β- (4-vinylbenzoyl) oxy-γ-butyrolactone, γ-methyl-γ- (4-vinylbenzoyl) oxy-γ-butyrolactone, α-ethyl-α- (4-vinylbenzoyl) oxy -Γ-butyrolactone, β-ethyl-β- (4-vinylbenzoyl) oxy-γ- Butyrolactone, γ-ethyl-γ- (4-vinylbenzoyl) oxy-γ-butyrolactone, α- (4-vinylbenzoyl) oxy-δ-valerolactone, β- (4-vinylbenzoyl) oxy-δ-valerolactone, γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ- (4-vinylbenzoyl) oxy-δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β -Methyl-β- (4-vinylbenzoyl) oxy-δ-valerolactone, γ-methyl-γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ-methyl-δ- (4-vinylbenzoyl) oxy -Δ-valerolactone, α-ethyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-ethyl-β- (4-vinylbenzoy ) Oxy-δ-valerolactone, γ-ethyl-γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ-ethyl-δ- (4-vinylbenzoyl) oxy-δ-valerolactone, vinylbenzoic acid 1 -Methylcyclohexyl, adamantyl vinyl benzoate, 2- (2-methyl) adamantyl vinyl benzoate, chloroethyl vinyl benzoate, 2-hydroxyethyl vinyl benzoate, 2,2-dimethylhydroxypropyl vinyl benzoate, 5-vinyl benzoate 5- Examples thereof include hydroxypentyl, trimethylolpropane vinylbenzoate, glycidyl vinylbenzoate, benzyl vinylbenzoate, phenyl vinylbenzoate, and naphthyl vinylbenzoate. Of these, a copolymer of 4-vinylbenzoic acid and tert-butyl 4-vinylbenzoate is preferable.

  Monomers that give the repeating unit represented by the above formula (III) include acrylic acid, tert-butyl acrylate, 2-methylbutyl acrylate, 2-methylpentyl acrylate, 2-ethylbutyl acrylate, and 3-methylpentyl acrylate. 2-methylhexyl acrylate, 3-methylhexyl acrylate, triethylcarbyl acrylate, 1-methyl-1-cyclopentyl acrylate, 1-ethyl-1-cyclopentyl acrylate, 1-methyl-1-cyclohexyl acrylate 1-ethyl-1-cyclohexyl acrylate, 1-methylnorbornyl acrylate, 1-ethylnorbornyl acrylate, 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, acrylic acid 3 -Hydroxy-1-adamanche , Tetrahydrofuranyl acrylate, tetrahydropyranyl acrylate, 1-methoxyethyl acrylate, 1-ethoxyethyl acrylate, 1-n-propoxyethyl acrylate, 1-isopropoxyethyl acrylate, n-butoxyethyl acrylate, 1-isobutoxyethyl acrylate, 1-sec-butoxyethyl acrylate, 1-tert-butoxyethyl acrylate, 1-tert-amyloxyethyl acrylate, 1-ethoxy-n-propyl acrylate, 1-acrylate Cyclohexyloxyethyl, methoxypropyl acrylate, ethoxypropyl acrylate, 1-methoxy-1-methyl-ethyl acrylate, 1-ethoxy-1-methyl-ethyl acrylate, trimethylsilyl acrylate, triethylsilyl acrylate, acrylic Dimethyl tert-butylsilyl phosphate, α- (acryloyl) oxy-γ-butyrolactone, β- (acryloyl) oxy-γ-butyrolactone, γ- (acryloyl) oxy-γ-butyrolactone, α-methyl-α- (acryloyl) Oxy-γ-butyrolactone, β-methyl-β- (acryloyl) oxy-γ-butyrolactone, γ-methyl-γ- (acryloyl) oxy-γ-butyrolactone, α-ethyl-α- (acryloyl) oxy-γ-butyrolactone Β-ethyl-β- (acryloyl) oxy-γ-butyrolactone, γ-ethyl-γ- (acryloyl) oxy-γ-butyrolactone, α- (acryloyl) oxy-δ-valerolactone, β- (acryloyl) oxy- δ-valerolactone, γ- (acryloyl) oxy-δ-valerolactone, δ- (acryloyl) oxy δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-methyl-β- (acryloyl) oxy-δ-valerolactone, γ-methyl-γ- (acryloyl) oxy -Δ-valerolactone, δ-methyl-δ- (acryloyl) oxy-δ-valerolactone, α-ethyl-α- (acryloyl) oxy-δ-valerolactone, β-ethyl-β- (acryloyl) oxy-δ -Valerolactone, γ-ethyl-γ- (acryloyl) oxy-δ-valerolactone, δ-ethyl-δ- (acryloyl) oxy-δ-valerolactone, 1-methylcyclohexyl acrylate, adamantyl acrylate, acrylic acid 2 -(2-methyl) adamantyl, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2,2-dimethyl acrylate Roxypropyl, 5-hydroxypentyl acrylate, trimethylolpropane acrylate, glycidyl acrylate, benzyl acrylate, phenyl acrylate, naphthyl acrylate, methacrylic acid, tert-butyl methacrylate, 2-methylbutyl methacrylate, methacrylic acid 2 -Methylpentyl, 2-ethylbutyl methacrylate, 3-methylpentyl methacrylate, 2-methylhexyl methacrylate, 3-methylhexyl methacrylate, triethylcarbyl methacrylate, 1-methyl-1-cyclopentyl methacrylate, 1 methacrylic acid -Ethyl-1-cyclopentyl, 1-methyl-1-cyclohexyl methacrylate, 1-ethyl-1-cyclohexyl methacrylate, 1-methylnorbornyl methacrylate, 1-ethylnor methacrylate Nyl, 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, tetrahydrofuranyl methacrylate, tetrahydropyranyl methacrylate, 1-methoxyethyl methacrylate, 1-ethoxyethyl methacrylate, 1-n-propoxyethyl methacrylate, 1-isopropoxyethyl methacrylate, n-butoxyethyl methacrylate, 1-isobutoxyethyl methacrylate, 1-sec-butoxyethyl methacrylate, methacrylic acid 1-tert-butoxyethyl, 1-tert-amyloxyethyl methacrylate, 1-ethoxy-n-propyl methacrylate, 1-cyclohexyloxyethyl methacrylate, methoxypropyl methacrylate, ethyl methacrylate Xylpropyl, 1-methoxy-1-methyl-ethyl methacrylate, 1-ethoxy-1-methyl-ethyl methacrylate, trimethylsilyl methacrylate, triethylsilyl methacrylate, dimethyl-tert-butylsilyl methacrylate, α- (methacryloyl) oxy- γ-butyrolactone, β- (methacryloyl) oxy-γ-butyrolactone, γ- (methacryloyl) oxy-γ-butyrolactone, α-methyl-α- (methacryloyl) oxy-γ-butyrolactone, β-methyl-β- (methacryloyl) Oxy-γ-butyrolactone, γ-methyl-γ- (methacryloyl) oxy-γ-butyrolactone, α-ethyl-α- (methacryloyl) oxy-γ-butyrolactone, β-ethyl-β- (methacryloyl) oxy-γ-butyrolactone , Γ-ethyl-γ- (methac Yl) oxy-γ-butyrolactone, α- (methacryloyl) oxy-δ-valerolactone, β- (methacryloyl) oxy-δ-valerolactone, γ- (methacryloyl) oxy-δ-valerolactone, δ- (methacryloyl) oxy -Δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-methyl-β- (methacloyl) oxy-δ-valerolactone, γ-methyl-γ- (methacloyl) Oxy-δ-valerolactone, δ-methyl-δ- (methacloyl) oxy-δ-valerolactone, α-ethyl-α- (methacloyl) oxy-δ-valerolactone, β-ethyl-β- (methacloyl) oxy- δ-valerolactone, γ-ethyl-γ- (methacloyl) oxy-δ-valerolactone, δ-ethyl-δ- (methacloyl) Xyl-δ-valerolactone, 1-methylcyclohexyl methacrylate, adamantyl methacrylate, 2- (2-methyl) adamantyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2,2-dimethylhydroxypropyl methacrylate, Examples include 5-hydroxypentyl methacrylate, trimethylolpropane methacrylate, glycidyl methacrylate, benzyl methacrylate, phenyl methacrylate, naphthyl methacrylate, and the like. Of these, a copolymer of acrylic acid and tert-butyl acrylate is preferred.

  In addition, as a monomer which comprises a shell part, the copolymer of at least one of 4-vinyl benzoic acid or acrylic acid and at least one of 4-vinyl benzoate tert-butyl or tert-butyl acrylate is also preferable. The monomer constituting the shell portion may be a monomer other than the monomer that gives the repeating unit represented by the above formula (II) and the above formula (III) as long as it has a structure having a radical polymerizable unsaturated bond. .

  Examples of the copolymerizable monomer that can be used include compounds having a radical polymerizable unsaturated bond selected from styrenes, allyl compounds, vinyl ethers, vinyl esters, crotonic acid esters and the like other than those described above. It is done.

  Specific examples of the styrenes listed as copolymerizable monomers that can be used as the monomer constituting the shell portion include styrene, tert-butoxystyrene, α-methyl-tert-butoxystyrene, 4- ( 1-methoxyethoxy) styrene, 4- (1-ethoxyethoxy) styrene, tetrahydropyranyloxystyrene, adamantyloxystyrene, 4- (2-methyl-2-adamantyloxy) styrene, 4- (1-methylcyclohexyloxy) styrene , Trimethylsilyloxystyrene, dimethyl-tert-butylsilyloxystyrene, tetrahydropyranyloxystyrene, benzylstyrene, trifluoromethylstyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, trichloro Styrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, And vinyl naphthalene.

  Specific examples of the allyl esters listed as copolymerizable monomers that can be used as the monomer constituting the shell portion include, for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate , Allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, allyloxyethanol, and the like.

  Specific examples of vinyl ethers listed as copolymerizable monomers that can be used as the monomer constituting the shell portion include hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether. , Chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl Vinyl ether, vinyl phenyl ether, vinyl Tolyl ether, vinyl chlorophenyl ether, vinyl 2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthranyl ether, and the like.

  Specific examples of the vinyl ester that can be used as a monomer constituting the shell portion include, for example, vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl Valate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinylphenylacetate, vinylacetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate, etc. Can be mentioned.

  Specific examples of the crotonic acid esters listed as copolymerizable monomers that can be used as the monomer constituting the shell portion include, for example, butyl crotonate, hexyl crotonate, glycerin monocrotonate, dimethyl itaconate, Examples include diethyl itaconate, dibutyl itaconate, dimethyl maleate, dibutyl fumarate, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleilonitrile and the like.

  Specific examples of the copolymerizable monomer that can be used as the monomer constituting the shell portion include the following formulas (IV) to (XIII).

  Among the above-mentioned formulas (IV) to (XIII), styrenes and crotonic acid esters are preferable as the copolymerization monomer that can be used as the monomer constituting the shell portion. Among the above-mentioned formulas (IV) to (XIII), copolymer monomers that can be used as the monomer constituting the shell part are styrene, benzylstyrene, chlorostyrene, vinylnaphthalene, butyl crotonate, hexyl crotonate, and maleic anhydride. Acid is preferred.

  In the core-shell hyperbranched polymer, the monomer giving the repeating unit represented by at least one of the above formula (II) or the above formula (III) is charged relative to the total amount of monomers used for the synthesis of the core-shell hyperbranched polymer. In some cases, it is preferably contained in the range of 10 to 90 mol%. It is more preferable that the monomer giving the above-mentioned repeating unit is contained in the range of 20 to 90 mol% at the time of charging with respect to the charging amount of the whole monomer used for the synthesis of the core-shell hyperbranched polymer.

  It is more preferable that the monomer giving the above-mentioned repeating unit is contained in the polymer in the range of 30 to 90 mol% at the time of charging with respect to the total amount of the monomer used for the synthesis of the core-shell hyperbranched polymer. In particular, the repeating unit represented by the above formula (II) or the above formula (III) in the shell portion is 50 to 100 mol% at the time of charging with respect to the total amount of monomers used for the synthesis of the core-shell hyperbranched polymer. , Preferably in the range of 80 to 100 mol%.

  A resist containing the core-shell hyperbranched polymer if the monomer giving the repeating unit is within the aforementioned range at the time of preparation with respect to the total amount of monomers used for the synthesis of the core-shell hyperbranched polymer. In the lithography development step using the composition, the exposed portion is preferably dissolved and removed in an alkaline solution, which is preferable.

  When the shell part of the core-shell hyperbranched polymer is a copolymer of a monomer giving a repeating unit represented by the above formula (II) or the above formula (III) and another monomer, all repeating units constituting the shell part On the other hand, the ratio of at least one of the formula (II) or the formula (III) is preferably 30 to 90 mol%, more preferably 50 to 70 mol%. When the amount of at least one of the above formula (II) or the above formula (III) in all the monomers forming the shell portion is within the above-mentioned range, the etching resistance is not impaired without inhibiting the effective alkali solubility of the exposed portion. It is preferable because functions such as wettability and glass transition temperature are increased.

  The amount of the repeating unit represented by at least one of the above formula (II) or the above formula (III) in the shell part and the other repeating unit is a charge ratio of the molar ratio at the time of introducing the shell part depending on the purpose. Can be adjusted.

(Polymerization initiator)
Next, the polymerization initiator used for the synthesis of the core-shell hyperbranched polymer will be described. Although it does not specifically limit as a polymerization initiator used for the synthesis | combination of a core-shell type hyperbranched polymer, For example, an azo polymerization initiator, a peroxide polymerization initiator, a redox polymerization initiator etc. can be mentioned.

As the azo polymerization initiator in the polymerization initiator used for the synthesis of the core-shell hyperbranched polymer, specifically, for example,
(Azo polymerization initiator)
Next, an azo polymerization initiator used for the synthesis of the core-shell hyperbranched polymer will be described. As the azo polymerization initiator used for the synthesis of the core-shell hyperbranched polymer, a known azo polymerization initiator can be used, and is not particularly limited and can be appropriately selected according to the purpose. Examples of the azo polymerization initiator include oil-soluble azo polymerization initiators, water-soluble azo polymerization initiators, and polymer azo polymerization initiators.

  Examples of the oil-soluble azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,3-dimethylbutyronitrile), 2,2′-azobis (2 -Methylbutyronitrile), 2,2'-azobis (2,3,3-trimethylbutyronitrile), 2,2'-azobis (2-isopropylbutyronitrile), 1,1'-azobis (cyclohexane- 1-carbonitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2- (carbamoylazo) isobuty Ronitrile, 4,4'-azobis (4-cyanovaleric acid), dimethyl-2,2'-azobisisobutyrate, dimethyl-2,2'-azobis (2-methylpropionate) 2,2'-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis (N- Examples include cyclohexyl-2-methylpropionamide.

  Examples of the water-soluble azo polymerization initiator include 2,2′-azobis (2-amidinopropane) hydrochloride, 4,4′-azobis-4-cyanoparellic acid, 2,2′-azobis (4-methoxy). -2,4-dimethylvaleronitrile) 1, [(cyano-1-methylethyl) azo] formamide, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2 '-Azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydrate, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis [N- (2 -Carboxyethyl) -2-methylpropionamidine] hydrate, 2,2'-azobis {2- [1- (2-hydroxyethyl) -2-imida Rin-2-yl] propane} dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis (1-imino-1-pyrrolidino-2-ethyl Propane) dihydrochloride, 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide, 2,2'-azobis [2-methyl-N- (2-hydroxyethylpropionamide)], 2,2′-azobis (N, N-dimethyleneiso-butyroamidine) hydrochloride and the like.

  Examples of the polymer azo polymerization initiator include polydimethylsiloxane unit-containing polymer azo polymerization initiator, polyethylene glycol unit-containing polymer azo polymerization initiator, and the like. Specific examples of the polydimethylsiloxane unit-containing polymer azo polymerization initiator include VPS-0501 and VPS-1001 manufactured by Wako Pure Chemical Industries. Specific examples of the polyethylene glycol unit-containing polymer azo polymerization initiator include VPE-0201, VPE-0401, and VPE-0601 manufactured by Wako Pure Chemical Industries.

  Among the various azo polymerization initiators described above, as the azo polymerization initiator used for the synthesis of the core-shell hyperbranched polymer, an oil-soluble azo polymerization initiator and a water-soluble azo polymerization initiator are preferable. Of these, 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl-2,2′-azobis (2-methylpropionate) ), 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2′-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride is particularly preferred.

(Peroxide polymerization initiator)
As the peroxide polymerization initiator in the polymerization initiator used for the synthesis of the core-shell hyperbranched polymer, specifically, for example, methyl ethyl peroxide, methyl isobutyl peroxide, acetylacetone peroxide, cyclohexanone peroxide, 1, 1,3,3-tetramethylbutyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, isobutyryl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, benzoyl peroxide , Dicumiperoxide, 2,5-dimethyl-2,5-di- (t-butylperoxyhexane), 1,3-bis (t-butylperoxyisopropyl) benzene, t-butylcumylperoxy Id, di-t-butyl peroxide, 2,5-dimethyl-2,5 di- (t-butylperoxy) hexene, tris (t-butylperoxy) triazine, 1,1-di-t-butylperoxy-3 , 3,5-trimethylcyclohexyl peroxide, 1,1-di-t-peroxycyclohexane, 2,2-di (t-butylperoxy) butane, 4,4-di-t-butylperoxyvaleric acid-n-butyl Ester, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1,3,3-tetramethylbutylperoxyneodecanoate, α-cumylperoxyneodecanoate, t -Butylperoxyneodecanoate, t-butylperoxyneopenanoate, t-hexylperoxypivalate, t-butylpe Ruoxypivalate, 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate, t-amylperoxy 2-ethylhexanoate, t-butylperoxy 2-ethylhexanoate, t-butylperoxy Isobutyrate, di-t-butylperoxyhexahydrotetraphthalate, t-amylperoxy 3,5,5-trimethylhexanoate, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxyacetate , T-butylperoxybenzoate, di-butylperoxytrimethyladipate, di-3-methoxybutylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-isopropyl Examples include ruperoxydicarbonate, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl carbonate, 1,6-bis (t-butylperoxycarbonoyl) hexane, diethylene glycol-bis (t-butylperoxycarbonate, etc. It is done.

  Among the various peroxide polymerization initiators mentioned above, the peroxide polymerization initiator as the polymerization initiator used for the synthesis of the core-shell hyperbranched polymer includes benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, and t-butyl. Peroxide and t-butyl peroxybenzoate are preferred.

  As the peroxide polymerization initiator described above, an oil-soluble peroxide polymerization initiator, a water-soluble peroxide polymerization initiator, and the like are used. Examples of the oil-soluble peroxide polymerization initiator include compounds corresponding to the following (1) to (7).

  (1) Ketone peroxide: For example, methyl ethyl peroxide, methyl isobutyl peroxide, acetyl acetone peroxide, cyclohexanone peroxide, and the like.

  (2) Hydroperoxide: For example, 1,1,3,3-tetramethylbutyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, and the like.

  (3) Diacyl peroxide: for example, isobutyryl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, benzoyl peroxide, and the like.

  (4) Dialkyl peroxides: for example, dicumyl peroxide, 2,5-dimethyl-2,5-di- (t-butylperoxyhexane, etc.), 1,3-bis (t-butylperoxyisopropyl) benzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5 di- (t-butylperoxy) hexene, tris (t-butylperoxy) triazine, and the like.

  (5) Peroxyketal: for example, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexyl peroxide, 1,1-di-t-peroxycyclohexane, 2,2-di (t- ) Butylperoxy) butane, 4,4-di-t-butylperoxyvaleric acid-n-butyl ester, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, and the like.

  (6) Alkyl perester: For example, 1,1,3,3-tetramethylbutylperoxyneodecanoate, α-cumylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxyneo Pentanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, t- Butylperoxy 2-ethylhexanoate, t-butylperoxyisobutyrate, di-t-butylperoxyhexahydrotetraphthalate, t-amylperoxy3,5,5-trimethylhexanoate, t-butylperoxy3,5 , 5-Trimethylhexanoate, t-Butylperu Shi acetate, t- butyl peroxybenzoate, di - butylperoxy trimethyl adipate, and the like.

  (7) Percarbonate: For example, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-isopropyl peroxydicarbonate, t-butyl Peroxyisopropyl carbonate, t-butylperoxy 2-ethylhexyl carbonate, 1,6-bis (t-butylperoxycarbonoyl) hexane, diethylene glycol-bis (t-butylperoxycarbonate, etc.

  Among the various compounds described above, (1) ketone peroxide, (2) hydroperoxide, (4) dialkyl peroxide and (6) alkyl perester are preferred as the peroxide polymerization initiator. Among the compounds preferable as the peroxide polymerization initiator, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl peroxide and t-butyl peroxybenzoate are particularly preferable compounds as the peroxide polymerization initiator.

  Examples of the water-soluble peroxide polymerization initiator include hydrogen peroxide, peracetic acid, ammonium persulfate, potassium persulfate, and sodium persulfate. As the water-soluble peroxide polymerization initiator, hydrogen peroxide, ammonium persulfate, and sodium persulfate are preferable.

(Redox polymerization initiator)
Specific examples of the redox polymerization initiator in the polymerization initiator used for the synthesis of the core-shell hyperbranched polymer include an oil-soluble redox polymerization initiator and a water-soluble redox polymerization initiator. Specific examples of the oil-soluble redox polymerization initiator include hydroperoxide (tret-butylhydroxyperoxide, cumenehydroxyperoxide, etc.), dialkyl peroxide (eg, lauroyl peroxide, etc.) and diacyl peroxide ( And oil-soluble peroxides such as benzoyl peroxide.

  Reducing agents used in combination with peroxide polymerization initiators include tertiary amines (triethylamine, tributylamine, etc.), naphthenates, mercaptans (mercaptoethanol, lauryl mercaptan, etc.), organometallic compounds (triethylaluminum, triethyl) And an oil-soluble reducing agent such as boron and diethyl zinc.

  Among the various compounds described above, preferred examples of the combination of the peroxide polymerization initiator and the reducing agent are specifically combinations of cumene hydroperoxide-triethylaluminum, benzoyl peroxide-triethylamine, and the like. .

  Examples of peroxide polymerization initiators include water-soluble substances such as persulfates (potassium persulfate, ammonium persulfate, etc.), hydrogen peroxide and hydroperoxides (tret-butylhydroxyperoxide, cumenehydroxyperoxide, etc.). A peroxide etc. are mentioned.

  Examples of the reducing agent used in combination with the peroxide polymerization initiator include divalent iron salt, sodium hydrogen sulfite, alcohol, dimethylaniline, and the like. Among the various compounds described above, preferred specific combinations of the peroxide polymerization initiator and the reducing agent include hydrogen peroxide-2valent iron salt, persulfate-sodium sulfite, and the like.

(solvent)
Next, the solvent used for the synthesis of the core-shell hyperbranched polymer will be described. The polymerization reaction of the core-shell hyperbranched polymer can be carried out without a solvent, but it is preferable to carry out the polymerization in various solvents shown below. The type of solvent used for the synthesis of the core-shell hyperbranched polymer is not particularly limited. For example, hydrocarbon solvents, ether solvents, halogenated hydrocarbon solvents, ketone solvents, alcohol solvents, nitrile solvents, Examples include ester solvents, carbonate solvents, amide solvents, and the like.

  Specific examples of the hydrocarbon solvent that is a solvent used for the synthesis of the core-shell hyperbranched polymer include benzene and toluene. Specific examples of the ether solvent that is a solvent used in the synthesis of the hyperbranched polymer include diethyl ether, tetrahydrofuran, diphenyl ether, anisole, and dimethoxybenzene.

  Specific examples of the halogenated hydrocarbon solvent that is a solvent used for the synthesis of the core-shell hyperbranched polymer include methylene chloride, chloroform, chlorobenzene, and the like. Specific examples of the ketone solvent that is a solvent used for the synthesis of the core-shell hyperbranched polymer include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Specific examples of the alcohol solvent that is used for the synthesis of the core-shell hyperbranched polymer include methanol, ethanol, propanol, and isopropanol.

  Specific examples of the nitrile solvent that is a solvent used for the synthesis of the core-shell hyperbranched polymer include acetonitrile, propionitrile, benzonitrile, and the like. Specific examples of the ester solvent that is a solvent used in the synthesis of the hyperbranched polymer include ethyl acetate and butyl acetate. Specific examples of the carbonate solvent that is a solvent used for the synthesis of the core-shell hyperbranched polymer include ethylene carbonate and propylene carbonate.

  Specific examples of the amide solvent that is a solvent used for the synthesis of the core-shell hyperbranched polymer include N, N-dimethylformamide and N, N-dimethylacetamide. The various solvents described above as the solvent used for the synthesis of the core-shell hyperbranched polymer may be used alone or in combination of two or more.

(Synthesis process of core-shell hyperbranched polymer)
Next, a method for synthesizing the core-shell hyperbranched polymer will be described. In the embodiment, a synthesis method of the core-shell hyperbranched polymer shown below will be described as a reaction method A. In synthesizing the core-shell hyperbranched polymer, living radical polymerization is performed by mixing the above-described alkoxyamine having a radically polymerizable vinyl group in the molecule with other monomers, a polymerization initiator, and a solvent as necessary.

In the polymerization, for example, the reaction system is made uniform by stirring the reaction system. As specific stirring conditions for the polymerization, for example, the required power for stirring per unit volume is preferably 0.01 kW / m ³ or more.
Moreover, it is preferable that a polymerization initiator is 0.001-2 times mol with respect to the alkoxyamine 1 which has the vinyl group in which a radical polymerization is possible in a molecule | numerator. In the core polymerization, living radical polymerization is performed for 0.5 to 10 hours with the reaction system kept at 20 to 150 ° C.

  In the core polymerization, the concentration of the alkoxyamine having a radical polymerizable vinyl group in the molecule is preferably 1 to 50% by mass with respect to the total amount of the reaction. A more preferable concentration is 3 to 20% by mass with respect to the total amount of reaction.

  In the core polymerization, a monomer containing an alkoxyamine having a radically polymerizable vinyl group in the molecule can be added later to a reaction vessel for carrying out the polymerization reaction to cause the reaction. Here, the mixing amount (addition amount) of the monomer per time with respect to the reaction vessel (reaction system) is set to be less than the total amount of monomers mixed in the reaction system.

  In the core polymerization, the monomer can be added later to the reaction vessel for carrying out the polymerization reaction to cause the reaction. Here, the mixing amount (addition amount) of the monomer per time with respect to the reaction vessel (reaction system) is set to be less than the total amount of monomers mixed in the reaction system.

  For example, by adding a monomer in a reaction system by dropping the monomer over a predetermined time, or by adding a constant amount of monomer that is divided into a plurality of times to the total amount of monomer mixed in the reaction system at regular intervals. Mixing the monomer into the reaction system according to the splitting system that mixes the monomer into the reaction system, etc., mixes the amount of monomer added (added) per reaction vessel (reaction system) to the reaction system. Less than the total amount of monomers to be treated.

  Further, for example, the monomer may be mixed into the reaction system by continuously dropping the monomer over a predetermined time. In this case, the mixing amount (addition amount) of the monomer mixed within a certain unit time with respect to the reaction system is less than the total amount of monomers mixed into the reaction system.

  When the monomer is mixed into the reaction system using a continuous system, the monomer dropping time is preferably, for example, 5 to 300 minutes. The more preferable dropping time of the monomer when mixing the monomer into the reaction system using a continuous system is 15 to 240 minutes. A more preferable dropping time in the case of mixing the monomer into the reaction system using a continuous system is 30 to 180 minutes.

  When mixing a monomer into a reaction system using a dividing formula, a single monomer is mixed and then a predetermined interval is opened to mix the next monomer. The predetermined time may be, for example, the time required for the mixed monomer to perform at least one polymerization reaction, or may be the time required for the mixed monomer to be uniformly dispersed throughout the reaction system. Alternatively, it may be the time required for the temperature of the reaction system changed by mixing the monomers to become stable.

  In addition, when the dripping time of the monomer with respect to the reaction system is too short, there is a possibility that a sufficient effect for suppressing a rapid increase in molecular weight may not be exhibited. In addition, if the dropping time of the monomer to the reaction system is too long, the total polymerization time from the start to the end of the synthesis of the hyperbranched core polymer becomes longer, which may increase the cost of synthesizing the hyperbranched core polymer. This is not preferable.

  After core polymerization, the hyperbranched core polymer synthesized by core polymerization is mixed with the monomer constituting the shell portion described above to perform shell polymerization. The concentration of the monomer in the shell polymerization is preferably 0.5 to 20 molar equivalents relative to the reaction active site of the hyperbranched core polymer. The more preferable monomer concentration in the shell polymerization is 1 to 150 molar equivalents relative to the reactive site of the hyperbranched core polymer. The core / shell ratio can be controlled by appropriately controlling the monomer amount with respect to the reactive site of the hyperbranched core polymer.

  The polymerization time for shell polymerization is preferably 0.1 to 10 hours depending on the molecular weight of the polymer. The reaction temperature during shell polymerization is preferably in the range of 20 to 150 ° C. A more preferable reaction temperature in the shell polymerization is in the range of 50 to 150 ° C. Moreover, when superposing | polymerizing at the temperature higher than the boiling point of a use solvent, you may make it pressurize in an autoclave, for example. As a result, a core-shell hyperbranched polymer having the core synthesized by the core polymerization and the shell synthesized by the shell polymerization is synthesized.

  Thereafter, the synthesized core-shell hyperbranched polymer is purified. In purifying the synthesized core-shell hyperbranched polymer, unreacted monomers after shell polymerization are removed. Before shell polymerization, unreacted monomers after core polymerization may be removed and then shell polymerization may be performed to remove unreacted monomers after shell polymerization.

As a method for removing unreacted monomers, for example, the following methods (S-1) to (S-2) can be carried out singly or in combination.
(S-1) The polymer is precipitated by adding a poor solvent to the reactant dissolved in the good solvent.
(S-2) The polymer is washed with a mixed solvent of a good solvent and a poor solvent.

  In the above (S-1) to (S-2), examples of the good solvent include halogenated hydrocarbons, nitro compounds, nitriles, ethers, ketones, esters, carbonates, and mixed solvents containing these. . Specific examples include tetrahydrofuran, chlorobenzene, chloroform, and the like. Examples of the poor solvent include methanol, ethanol, 1-propanol, 2-propanol, water, or a solvent obtained by combining these solvents. The method for removing the unreacted monomer is not particularly limited to the method described above.

(Molecular structure)
Next, the molecular structure of the core-shell hyperbranched polymer described above will be described. The branching degree (Br) of the core part in the core-shell hyperbranched polymer is preferably 0.3 to 0.5. A more preferable degree of branching (Br) is 0.4 to 0.5. When the degree of branching (Br) of the core portion in the hyperbranched polymer is in the above range, it is preferable because entanglement between polymer molecules is small and surface roughness on the pattern side wall is suppressed.

Here, the branching degree (Br) of the core part in the core-shell hyperbranched polymer can be determined as follows by measuring ¹ H-NMR of the product. That is, using the integral ratio H1 ° of protons at the —CH ₂ O site appearing at 4.6 ppm and the integral ratio H2 ° of protons at the —CHO site appearing at 4.8 ppm, the following mathematical formula (A) is calculated. Can be calculated. When polymerization proceeds at both the —CH ₂ O site and the —CHO site and branching increases, the value of the degree of branching (Br) approaches 0.5.

  The weight average molecular weight (Mw) of the core part in the core-shell hyperbranched polymer is preferably 300 to 10,000, more preferably 500 to 10,000, and 1,000 to 10,000. Is most preferred. When the molecular weight of the core part is in such a range, the core part takes a spherical shape and is preferable because solubility in a reaction solvent can be secured in the acid-decomposable group introduction reaction. Further, it is preferable in the hyperbranched polymer having excellent film forming property and having an acid-decomposable group derived in the core part in the above molecular weight range because it is advantageous for inhibiting dissolution of the unexposed part.

  The polydispersity (Mw / Mn) of the core portion in the core-shell hyperbranched polymer is preferably 1 to 5, and more preferably 1 to 3. If it is in such a range, there is no possibility of causing adverse effects such as insolubilization after exposure, which is desirable.

  The weight average molecular weight (M) of the core-shell hyperbranched polymer is preferably 500 to 50,000, more preferably 2,000 to 50,000, and most preferably 3,000 to 50,000. When the weight average molecular weight (M) of the hyperbranched polymer is in such a range, the resist containing the hyperbranched polymer has good film formability and has the strength of the processing pattern formed in the lithography process. The shape can be kept. It also has excellent dry etching resistance and good surface roughness.

  Here, the weight average molecular weight (Mw) of the core part in the core-shell hyperbranched polymer is obtained, for example, by preparing a 0.5 mass% tetrahydrofuran solution and performing GPC (Gel Permeation Chromatography) measurement at a temperature of 40 ° C. Can do. In measurement, tetrahydrofuran is used as a mobile solvent, styrene is used as a standard substance, and two TSKgel HXL-M (manufactured by Tosoh Corporation) are connected to a column using a GPC HLC-8020 type apparatus.

For the weight average molecular weight (M) of the hyperbranched polymer described above, the introduction ratio (configuration ratio) of each repeating unit of the polymer having an acid-decomposable group introduced is determined by ¹ H-NMR, and the core portion of the core-shell hyperbranched polymer Based on the weight average molecular weight (Mw), the introduction ratio of each structural unit and the molecular weight of each structural unit can be used for calculation. The shape of the synthesized core-shell hyperbranched polymer can be judged to be spherical from the primary and secondary hydrogens by NMR.

(Substances used for star polymer synthesis)
Next, substances used for the synthesis of the star polymer of the embodiment will be described. The star polymer can be synthesized by three kinds of methods. The substances used in each method are as follows.

(1) Monomer constituting the arm part + monomer constituting the core part + polymerization initiator + nitroxide + solvent (2) Monomer constituting the arm part + monomer constituting the core part + alkoxyamine + solvent (3) Arm part Monomer constituting the monomer + monomer constituting the core portion + alkoxyamine + nitroxide + solvent

  About a polymerization initiator and a solvent, the same thing as the time of synthesize | combining a core-shell type hyperbranched polymer can be used.

<Monomer composing arm part>
As the monomer constituting the arm portion, those described in the monomer constituting the shell portion of the core-shell hyperbranched polymer can be used.

<Monomer constituting the core>
Below, the monomer which can be used for formation of the core part of a star polymer is demonstrated. The core portion of the star polymer can be formed using monomers corresponding to the following (1) to (12). The monomer has two or more functional groups involved in the polymerization reaction in its molecular structure.

(1) Aromatic vinyl hydrocarbons (2) Vinyl hydrocarbons (3) Ester group-containing vinyl monomers (4) Sulfone group-containing vinyl monomers, vinyl sulfate monoesters and their salts ( 5) Phosphoric group-containing vinyl monomers (6) Hydroxyl group-containing vinyl monomers (7) Nitrogen-containing vinyl monomers (8) Halogen element-containing vinyl monomers (9) Carboxyl group-containing vinyl monomers Monomer and its salt (10) Silicon-containing vinyl monomer (11) Monomer included in the existing patents (12) Vinyl monomer in which an initiator site is introduced into the vinyl monomer structure

  Specific examples of the aromatic vinyl hydrocarbon in the above (1) include, for example, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, divinyltoluene, 1,4-diisopropenylbenzene, tri And vinyl benzene. Examples of the vinyl hydrocarbon in the above (2) include isoprene, butadiene, 3-methyl-1,2-butadiene, 2,3-dimethyl 1,3-butadiene, pentadiene, hexadiene, octadiene, 1,3,5- Examples include hexatriene, cyclopentadiene, cyclohexadiene, and trivinylcyclohexane.

  Specific examples of the ester group-containing vinyl monomer in (3) above include, for example, diallyl maleate, diallyl phthalate, divinyl adipate, diallyl adipate, divinyl fumarate, divinyl maleate, and itaconic acid. Divinyl, vinyl cinnamate, vinyl crotonic acid, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meta ) Acrylate, glycerol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, 1,2-cyclohexanediol di (meth) acrylate, 1,3-cyclohexanediol di (meth) acrylate Rate, 1,4-cyclohexanediol di (meth) acrylate, vinyl (meth) acrylate, polyethylene glycol (molecular weight 300) di (meth) acrylate, polypropylene glycol (molecular weight 500), such as diacrylate.

  Specific examples of the sulfone group-containing vinyl monomers, vinyl sulfate monoesters and salts thereof in (4) above include, for example, divinyl sulfide, divinyl sulfone, divinyl sulfoxide, diallyl disulfide. , Etc. Specific examples of the phosphate group-containing vinyl monomer in (5) above include, for example, triallyl phosphate, tri (4-vinylphenyl) phosphate, tri (4-vinylbenzyl) phosphate, diallylmethyl. Examples include phosphoric acid ester, di (4-vinylphenyl) methyl phosphoric acid ester, di (4-vinylbenzyl) methyl phosphoric acid ester, and diallylphenyl phosphate.

  Examples of the hydroxyl group-containing vinyl monomer in the above (6) include divinyl glycol (1,5-hexadiene-3,4-diol), 1,2-divinyloxy-3-propanol, 1,3-divinyloxy. -2-propanol. Specific examples of the nitrogen-containing vinyl monomer in (7) described above include diallylamine, triallylamine, diallyl isocyanurate, diallyl cyanurate, 1-cyanobutadiene, methylenebisacrylamide, bismaleimide, and the like. Can be mentioned.

  Specific examples of the halogen element-containing vinyl monomer in (8) described above include 1,4-divinylperfluorobutane, chloroprene, diallylamine hydrochloride, and the like. Specific examples of the carboxyl group-containing vinyl monomer and salt thereof in (9) above include, for example, carboxyls such as monoallyl maleate, monoallyl phthalate, monovinyl fumarate, monovinyl maleate, monovinyl itaconate, and the like. Examples thereof include group-containing vinyl monomers, and alkali metal salts and alkaline earth metal salts thereof. Examples of the alkali metal salt include sodium salt and potassium salt. Examples of alkaline earth metal salts include calcium salts and magnesium salts.

  Specific examples of the silicon-containing vinyl monomer in (10) described above include, for example, divinyldimethylsilane, 1,3-divinyltetramethyldisiloxane, 1,1,3,3-tetramethyl-1, 3-divinyldisiloxane, and the like.

  Specific examples of the monomer included in the above-mentioned patent in (11) above include, for example, application numbers 2005-327710, 2006-026581, 2006-029687, 2006-055047, 2006-066513, PCT / JP2006 / 308634, WO 2005/061566 A1, and the like.

  Specific examples of the vinyl monomer obtained by introducing an initiator site into the vinyl monomer structure in (12) described above include 2- (2-bromopropionyloxy) ethyl acrylate, 2- (2 -Bromopropionyloxy) ethyl acrylate, 2- (2-bromopropionyloxy) butyl acrylate, 2- (2-bromopropionyloxy) ethyl methacrylate, 2- (2-bromopropionyloxy) ethyl methacrylate, m- (1 -Chloroethyl) styrene, monomers represented by the following formula (I), and the like.

  Y in the above formula (I) represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms. The number of carbon atoms in Y is preferably 1-8. The more preferable carbon number in Y is 1-6. Y in the above formula (I) may contain a hydroxyl group or a carboxyl group.

  Specific examples of Y in the formula (I) include a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, an isobutylene group, an amylene group, a hexylene group, and a cyclohexylene group. . Y in the formula (I) is a group in which the above groups are bonded, or a group in which “—O—”, “—CO—”, or “—COO—” is interposed in each of the above groups. Is mentioned.

Among the groups described above, Y in the formula (I) is preferably an alkylene group having 1 to 8 carbon atoms. Among the alkylene groups having 1 to 8 carbon atoms, Y in the formula (I) is more preferably a linear alkylene group having 1 to 8 carbon atoms. More preferable alkylene groups include, for example, a methylene group, an ethylene group, an —OCH ₂ — group, and an —OCH ₂ CH ₂ — group. The monomer corresponding to the above formula (I) represents a halogen atom (halogen group) such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Specifically, as the monomer corresponding to the above formula (I), for example, among the halogen atoms described above, a chlorine atom and a bromine atom are preferable.

  Among the vinyl monomers in which an initiator site is introduced into the vinyl monomer structure in (12) described above, as the monomer represented by the above formula (I), specifically, for example, chloromethylstyrene , Bromomethylstyrene, p- (1-chloroethyl) styrene, bromo (4-vinylphenyl) phenylmethane, 1-bromo-1- (4-vinylphenyl) propan-2-one, 3-bromo-3- (4 -Vinylphenyl) propanol, etc.

  As a monomer which comprises the core part of a star polymer, in addition to the monomer applicable to said (1)-(12), another monomer can be included. The other monomer is not particularly limited as long as it is a monomer capable of radical polymerization, and can be appropriately selected according to the purpose. Examples of other monomers capable of radical polymerization include (meth) acrylic acid and (meth) acrylic acid esters, vinyl benzoic acid, vinyl benzoic acid esters, styrenes, allyl compounds, vinyl ethers, and vinyl esters. And compounds having a radical polymerizable unsaturated bond selected from the above.

  Specific examples of the (meth) acrylic acid esters mentioned as other monomers capable of radical polymerization include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, and tert-acrylate. -Butyl, 2-methylbutyl acrylate, 2-methylpentyl acrylate, 2-ethylbutyl acrylate, 3-methylpentyl acrylate, 2-methylhexyl acrylate, 3-methylhexyl acrylate, triethylcarbyl acrylate, acrylic 1-methyl-1-cyclopentyl acrylate, 1-ethyl-1-cyclopentyl acrylate, 1-methyl-1-cyclohexyl acrylate, 1-ethyl-1-cyclohexyl acrylate, 1-methylnorbornyl acrylate, 1 acrylic acid -Ethylnorbornyl, acrylic acid 2- Tyl-2-adamantyl, 2-ethyl-2-adamantyl acrylate, 3-hydroxy-1-adamantyl acrylate, tetrahydrofuranyl acrylate, tetrahydropyranyl acrylate, 1-methoxyethyl acrylate, 1-ethoxyethyl acrylate 1-n-propoxyethyl acrylate, 1-isopropoxyethyl acrylate, n-butoxyethyl acrylate, 1-isobutoxyethyl acrylate, 1-sec-butoxyethyl acrylate, 1-tert-butoxyethyl acrylate 1-tert-amyloxyethyl acrylate, 1-ethoxy-n-propyl acrylate, 1-cyclohexyloxyethyl acrylate, methoxypropyl acrylate, ethoxypropyl acrylate, 1-methoxy-1-methyl-ethyl acrylate 1-ethoxy-1-methyl-ethyl acrylate, trimethylsilyl acrylate, triethylsilyl acrylate, dimethyl-tert-butylsilyl acrylate, α- (acryloyl) oxy-γ-butyrolactone, β- (acryloyl) oxy-γ-butyrolactone , Γ- (acryloyl) oxy-γ-butyrolactone, α-methyl-α- (acryloyl) oxy-γ-butyrolactone, β-methyl-β- (acryloyl) oxy-γ-butyrolactone, γ-methyl-γ- (acroyl) ) Oxy-γ-butyrolactone, α-ethyl-α- (acryloyl) oxy-γ-butyrolactone, β-ethyl-β- (acryloyl) oxy-γ-butyrolactone, γ-ethyl-γ- (acryloyl) oxy-γ- Butyrolactone, α- (acryloyl) oxy-δ-valerolactone, β- (a Cloyl) oxy-δ-valerolactone, γ- (acryloyl) oxy-δ-valerolactone, δ- (acryloyl) oxy-δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valero Lactone, β-methyl-β- (acryloyl) oxy-δ-valerolactone, γ-methyl-γ- (acryloyl) oxy-δ-valerolactone, δ-methyl-δ- (acryloyl) oxy-δ-valerolactone, α-ethyl-α- (acryloyl) oxy-δ-valerolactone, β-ethyl-β- (acryloyl) oxy-δ-valerolactone, γ-ethyl-γ- (acryloyl) oxy-δ-valerolactone, δ- Ethyl-δ- (acryloyl) oxy-δ-valerolactone, 1-methylcyclohexyl acrylate, adamantyl acrylate, 2- (2-methyl acrylate) Chill) adamantyl, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, glycidyl acrylate, benzyl acrylate, phenyl acrylate, naphthyl acrylate, methacrylic acid Methyl, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, 2-methylbutyl methacrylate, 2-methylpentyl methacrylate, 2-ethylbutyl methacrylate, 3-methylpentyl methacrylate, methacrylic acid 2-methylhexyl, 3-methylhexyl methacrylate, triethylcarbyl methacrylate, 1-methyl-1-cyclopentyl methacrylate, 1-ethyl-1-cyclopentyl methacrylate, meta 1-methyl-1-cyclohexyl laurate, 1-ethyl-1-cyclohexyl methacrylate, 1-methylnorbornyl methacrylate, 1-ethylnorbornyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-methacrylic acid 2- Ethyl-2-adamantyl, 3-hydroxy-1-adamantyl methacrylate, tetrahydrofuranyl methacrylate, tetrahydropyranyl methacrylate, 1-methoxyethyl methacrylate, 1-ethoxyethyl methacrylate, 1-n-propoxyethyl methacrylate, 1-isopropoxyethyl methacrylate, n-butoxyethyl methacrylate, 1-isobutoxyethyl methacrylate, 1-sec-butoxyethyl methacrylate, 1-tert-butoxyethyl methacrylate, 1-tert-methacrylate Miroxyethyl, 1-ethoxy-n-propyl methacrylate, 1-cyclohexyloxyethyl methacrylate, methoxypropyl methacrylate, ethoxypropyl methacrylate, 1-methoxy-1-methyl-ethyl methacrylate, 1-ethoxy-1-methacrylate Methyl-ethyl, trimethylsilyl methacrylate, triethylsilyl methacrylate, dimethyl-tert-butylsilyl methacrylate, α- (methacryloyl) oxy-γ-butyrolactone, β- (methacryloyl) oxy-γ-butyrolactone, γ- (methacryloyl) oxy- γ-butyrolactone, α-methyl-α- (methacryloyl) oxy-γ-butyrolactone, β-methyl-β- (methacryloyl) oxy-γ-butyrolactone, γ-methyl-γ- (methacryloyl) oxy-γ-butyrolacto , Α-ethyl-α- (methacloyl) oxy-γ-butyrolactone, β-ethyl-β- (methacroyl) oxy-γ-butyrolactone, γ-ethyl-γ- (methacloyl) oxy-γ-butyrolactone, α- ( Methacryloyl) oxy-δ-valerolactone, β- (methacryloyl) oxy-δ-valerolactone, γ- (methacryloyl) oxy-δ-valerolactone, δ- (methacryloyl) oxy-δ-valerolactone, α-methyl-α -(4-vinylbenzoyl) oxy-δ-valerolactone, β-methyl-β- (methacryloyl) oxy-δ-valerolactone, γ-methyl-γ- (methacryloyl) oxy-δ-valerolactone, δ-methyl- δ- (methacryloyl) oxy-δ-valerolactone, α-ethyl-α- (methacryloyl) oxy-δ-valerolactone, β- Til-β- (methacloyl) oxy-δ-valerolactone, γ-ethyl-γ- (methacloyl) oxy-δ-valerolactone, δ-ethyl-δ- (methacloyl) oxy-δ-valerolactone, methacrylic acid 1- Methyl cyclohexyl, adamantyl methacrylate, 2- (2-methyl) adamantyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2,2-dimethylhydroxypropyl methacrylate, 5-hydroxypentyl methacrylate, trimethylol methacrylate Examples include propane, glycidyl methacrylate, benzyl methacrylate, phenyl methacrylate, naphthyl methacrylate, and the like.

  Specific examples of the vinyl benzoate listed as other monomers capable of radical polymerization include, for example, methyl vinyl benzoate, ethyl vinyl benzoate, propyl vinyl benzoate, n-butyl vinyl benzoate, and vinyl. Tert-butyl benzoate, 2-methylbutyl vinylbenzoate, 2-methylpentyl vinylbenzoate, 2-ethylbutyl vinylbenzoate, 3-methylpentyl vinylbenzoate, 2-methylhexyl vinylbenzoate, 3-methylvinylbenzoate Hexyl, triethylcarbyl vinylbenzoate, 1-methyl-1-cyclopentyl vinylbenzoate, 1-ethyl-1-cyclopentyl vinylbenzoate, 1-methyl-1-cyclohexyl vinylbenzoate, 1-ethyl-1 vinylbenzoate -Cyclohexyl, vinylbenzoic acid 1- Tilnorbornyl, 1-ethylnorbornyl vinylbenzoate, 2-methyl-2-adamantyl vinylbenzoate, 2-ethyl-2-adamantyl vinylbenzoate, 3-hydroxy-1-adamantyl vinylbenzoate, tetrahydrofuranyl vinylbenzoate, Tetrahydropyranyl vinylbenzoate, 1-methoxyethyl vinylbenzoate, 1-ethoxyethyl vinylbenzoate, 1-n-propoxyethyl vinylbenzoate, 1-isopropoxyethyl vinylbenzoate, n-butoxyethyl vinylbenzoate, 1-isobutoxyethyl vinylbenzoate, 1-sec-butoxyethyl vinylbenzoate, 1-tert-butoxyethyl vinylbenzoate, 1-tert-amyloxyethyl vinylbenzoate, 1-ethoxy-n-propyl vinylbenzoate Vinyl repose 1-cyclohexyloxyethyl acid, methoxypropyl vinylbenzoate, ethoxypropyl vinylbenzoate, 1-methoxy-1-methyl-ethyl vinylbenzoate, 1-ethoxy-1-methyl-ethyl vinylbenzoate, trimethylsilyl vinylbenzoate, Triethylsilyl vinylbenzoate, dimethyl-tert-butylsilyl vinylbenzoate, α- (4-vinylbenzoyl) oxy-γ-butyrolactone, β- (4-vinylbenzoyl) oxy-γ-butyrolactone, γ- (4-vinylbenzoyl) ) Oxy-γ-butyrolactone, α-methyl-α- (4-vinylbenzoyl) oxy-γ-butyrolactone, β-methyl-β- (4-vinylbenzoyl) oxy-γ-butyrolactone, γ-methyl-γ- ( 4-vinylbenzoyl) oxy-γ-butyrolactone, α-ethyl-α- (4-vinylbenzoyl) oxy-γ-butyrolactone, β-ethyl-β- (4-vinylbenzoyl) oxy-γ-butyrolactone, γ-ethyl-γ- (4-vinylbenzoyl) oxy- γ-butyrolactone, α- (4-vinylbenzoyl) oxy-δ-valerolactone, β- (4-vinylbenzoyl) oxy-δ-valerolactone, γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ -(4-vinylbenzoyl) oxy-δ-valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-methyl-β- (4-vinylbenzoyl) oxy-δ-valero Lactone, γ-methyl-γ- (4-vinylbenzoyl) oxy-δ-valerolactone, δ-methyl-δ- (4-vinylbenzoyl) oxy-δ-ba Lerolactone, α-ethyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-ethyl-β- (4-vinylbenzoyl) oxy-δ-valerolactone, γ-ethyl-γ- (4-vinyl Benzoyl) oxy-δ-valerolactone, δ-ethyl-δ- (4-vinylbenzoyl) oxy-δ-valerolactone, 1-methylcyclohexyl vinylbenzoate, adamantyl vinylbenzoate, 2- (2-methylvinylbenzoate) ) Adamantyl, chloroethyl vinylbenzoate, 2-hydroxyethyl vinylbenzoate, 2,2-dimethylhydroxypropyl vinylbenzoate, 5-hydroxypentyl vinylbenzoate, trimethylolpropane vinylbenzoate, glycidyl vinylbenzoate, vinylbenzoic acid Benzyl, phenyl vinyl benzoate, vinyl benzo Acid naphthyl, and the like.

  Specific examples of styrenes listed as other monomers capable of radical polymerization include, for example, styrene, benzyl styrene, trifluoromethyl styrene, acetoxy styrene, chlorostyrene, dichlorostyrene, trichlorostyrene, and tetrachlorostyrene. , Pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, vinylnaphthalene, etc. Can be mentioned.

  Specific examples of allyl compounds listed as other monomers capable of radical polymerization include, for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate. , Allyl acetoacetate, allyl lactate, allyloxyethanol, and the like.

  Specific examples of vinyl ethers listed as other monomers capable of radical polymerization include, for example, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1- Methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, vinyl phenyl ether, vinyl Tril ether, vinyl chlorfe Ether, vinyl 2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthranyl ether, and the like.

  Specific examples of vinyl esters listed as other monomers capable of radical polymerization include, for example, vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl barate, vinyl caproate, Examples include vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinylphenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexyl carboxylate, and the like.

  Among the monomers corresponding to the above (1) to (11), as monomers constituting the core of the star polymer, aromatic vinyl hydrocarbons, vinyl hydrocarbons, ester group-containing vinyl monomers, Hydroxyl group-containing vinyl monomers, carboxyl group-containing vinyl monomers and salts thereof, vinyl monomers in which an initiator site is introduced into the vinyl monomer structure, and the like are preferable. Among the other monomers capable of radical polymerization described above, monomers constituting the core of the star branch polymer include (meth) acrylic acid, (meth) acrylic esters, vinyl benzoic acid, and vinyl benzoic acid ester. , Vinyl ethers, vinyl esters and the like are preferable.

  In the star polymer, the ratio of the repeating units derived from the monomers represented by the above (1) to (12) is preferably 5 to 100 mol% with respect to all the repeating units constituting the core of the star polymer. It is more preferable that it is 20-100 mol%, and it is still more preferable that it is 50-100 mol%. If it exists in the range mentioned above, since the core part of a star polymer takes a spherical form advantageous to the entanglement suppression between the molecules which comprise the core part of a star polymer, it is preferable.

  The monomer corresponding to the core part is preferably contained in an amount of 10 to 99 mol% with respect to all repeating units constituting the star polymer.

(Nitroxide)
Examples of the nitroxide include 2,2,6,6-tetramethyl-1-piperidinyloxy, 4-amino-2,2,6,6-tetramethyl-1-piperidinyloxy, 4-hydroxy- 2,2,6,6-tetramethyl-1-piperidinyloxy, 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy, 4,4-dimethyl-3-oxazolinyl Oxy, phenyl-t-butyl nitroxide, 2,2,5,5-tetramethyl-1-pyrrolidinyloxy, 2,2,2-di (4-t-octylphenyl) -1-picrylhydrazyl, Etc.

(Alkoxyamine)
Examples of the alkoxyamine include a compound represented by the following formula (XIV).

Z in the above formula (XIV) represents an organic group having 1 or more carbon atoms. R _{1 to} R ₈ in the above formula (XIV) represent a compound selected from hydrogen and a linear or branched organic group having 1 to 20 carbon atoms. R _{1 to} R ₈ in the above formula (XIV) may be the same as or different from each other. N in the formula (XIV) represents 0 or an integer of 1 or more.

  Specific examples of alkoxyamine include 1-phenyl-1 (-2,2,6,6-tetramethyl-1-piperidinyloxy) ethane and 1-phenyl-1-2,2,6. , 6-tetramethyl-1-piperidinyloxy) ethanol, 2,2,6,6-tetramethyl-1- (1-phenylethoxy) -4-piperidinol, 1-phenyl-1- (2,6- Diethyl-2,3,6-trimethyl-4-acetoxypiperidinyloxy) ethane, and the like.

  The method for synthesizing the alkoxyamine described above is not particularly limited, but can be synthesized using, for example, nitroxide or di-t-butyl peroxide. The above-mentioned alkoxyamine can be synthesized more easily by using, for example, ethylbenzene. As a synthesis method of alkoxyamine, for example, a synthesis method according to “Macromolecules, 1998, 31, 4659-4661” and the like can be cited as a reference example. As 2,2,6,6-tetramethyl-1- (1-phenylethoxy) -4-piperidinol, those commercially available from Aldrich can also be used.

(Star polymer synthesis process)
Next, a method for synthesizing a star polymer will be described. In the embodiment, a method for synthesizing a star polymer shown below will be described as a reaction method B. In the reaction method B, the description of the same part as the reaction method A described above is omitted. The star polymer can be synthesized by the following three methods.

(1) Monomer constituting the arm part + monomer constituting the core part + polymerization initiator + nitroxide + solvent (2) Monomer constituting the arm part + monomer constituting the core part + alkoxyamine + solvent (3) Arm part Monomer constituting the monomer + monomer constituting the core portion + alkoxyamine + nitroxide + solvent

  As described above, the star polymer is synthesized by appropriately combining a monomer, a solvent, a polymerization initiator, a nitroxide, and an alkoxyamine with living radical polymerization. Living radical polymerization is carried out for 0.5 to 10 hours with the reaction system kept at 20 to 150 ° C. The concentration of the monomer constituting the arm part is desirably 1 to 99% by mass, and more preferably 1 to 50% by mass with respect to the total amount of the reaction.

  In the method (1), the nitroxide is preferably 0.001 to 10% by mass with respect to the monomer constituting the arm part, and the polymerization initiator is preferably 50 to 200 mol% with respect to the nitroxide.

  In the method (2), the amount of alkoxyamine is preferably 0.001 to 10% by mass with respect to the monomer constituting the arm portion.

  In the method (3), the alkoxyamine is preferably 0.001 to 10% by mass with respect to the monomer constituting the arm portion, and the nitroxide is preferably 0.1 to 100 mol% with respect to the alkoxyamine.

  Then, the monomer which comprises the core part mentioned above is added to the reaction system in which living radical polymerization is performed, and a star polymer is synthesize | combined. Thereby, during the synthesis | combination of the polymer used as an arm part by living radical polymerization, arm parts can be coupled and a core part can be formed. After the monomer constituting the core part is added, the living radical polymerization is stopped immediately or after a predetermined time.

  The ratio of the monomer that constitutes the arm part to the monomer that constitutes the core part can be appropriately adjusted depending on the purpose and application, but the monomer constituting the arm part is 1 It is desirable that it is -100 times mol.

  After adding the monomers represented by the above (1) to (12), the living radical polymerization is stopped within a predetermined time. Here, the predetermined time is a time required until the synthesis of the star polymer proceeds until the target molecular weight level is reached, and is a time that can be appropriately set according to the molecular weight of the target star polymer. The method for terminating the living radical polymerization is not particularly limited, and for example, a method such as cooling the reaction system during the living radical polymerization can be used.

(Molecular structure)
Next, the molecular structure of the above-described star polymer will be described. The shape of the star polymer depends on the difference between the GPC measurement value and the MALLS value using the GPC (1/4) measurement value and the multi-angle light scattering detector (hereinafter referred to as MALLS) value. It is determined whether or not it is a star polymer. When the value of GPC measurement and the value of MALLS differ greatly, it can be determined that the star polymer is spherical.

  For the weight average molecular weight (M) of the star polymer, polypolystyrene was used as a standard substance for GPC measurement. Under the same conditions, the absolute molecular weight was measured by MALLS (He-Ne laser, DAWN DSP-F manufactured by Wyatt Technology).

  The polydispersity (Mw / Mn) in the star polymer is preferably 1 to 5, and more preferably 1 to 3. If it is in such a range, there is no possibility of causing adverse effects such as insolubilization after exposure, which is desirable.

  The above-mentioned star polymer has a weight average molecular weight (M) of preferably 500 to 50,000, more preferably 2,000 to 50,000, and most preferably 3,000 to 50,000. When the weight average molecular weight (M) of the star polymer is in such a range, the resist containing the star polymer has good film formability and has a shape of a processing pattern formed in the lithography process, and thus has a shape. Can keep. It also has excellent dry etching resistance and good surface roughness.

(Use of hyperbranched polymers and star polymers)
Examples of the use of the core-shell hyperbranched polymer synthesized according to the reaction method A and the star polymer synthesized according to the reaction method B include a photoresist. Moreover, as another use of the above-mentioned core-shell hyperbranched polymer and star polymer, for example, ultraviolet curable resin for producing printing plate making, hard coat agent, antireflection film, dental material, adhesive / adhesive agent, paint, etc. Is mentioned.

  Other uses of the above-described core-shell hyperbranched polymer and star polymer include, for example, dispersion of pigments, fine metal particles, organic EL, dye laser color filter resists, use as stabilizers, optical fibers, optical fibers, and the like. Use as an optical material such as a waveguide.

(Resist composition)
Next, a resist composition using a core-shell hyperbranched polymer or a star polymer will be described. The amount of the core-shell hyperbranched polymer or star polymer in the resist composition using the core-shell hyperbranched polymer or star polymer (hereinafter simply referred to as “resist composition”) is 4 with respect to the total amount of the resist composition. -40 mass% is preferable and 4-20 mass% is more preferable.

  The resist composition includes the core-shell hyperbranched polymer described above and a photoacid generator. The resist composition may further contain an acid diffusion inhibitor (acid scavenger), a surfactant, other components, a solvent, and the like, if necessary.

  The photoacid generator contained in the resist composition is not particularly limited as long as it generates an acid when irradiated with ultraviolet rays, X-rays, electron beams, and the like, and various known photoacid generators can be used. It can be suitably selected from the inside according to the purpose. Specifically, examples of the photoacid generator include onium salts, sulfonium salts, halogen-containing triazine compounds, sulfone compounds, sulfonate compounds, aromatic sulfonate compounds, and sulfonate compounds of N-hydroxyimide.

  Examples of the onium salt contained in the above-mentioned photoacid generator include diaryl iodonium salts, triaryl selenonium salts, triaryl sulfonium salts, and the like. Examples of the diaryliodonium salt include diphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium hexafluoroantimonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, Examples thereof include bis (4-tert-butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium hexafluoroantimonate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate, and the like.

  Specific examples of the triarylselenonium salt contained in the onium salt described above include, for example, triphenylselenonium hexafluorophosphonium salt, triphenylselenonium borofluoride salt, triphenylselenonium hexafluoroantimonate salt, and the like. Is mentioned. Examples of the triarylsulfonium salt contained in the above onium salt include, for example, triphenylsulfonium hexafluorophosphonium salt, triphenylsulfonium hexafluoroantimonate salt, diphenyl-4 monothiophenoxyphenylsulfonium hexafluoroantimonate salt, diphenyl -4-thiophenoxyphenylsulfonium pentafluorohydroxyantimonate salt, and the like.

  Examples of the sulfonium salt contained in the photoacid generator include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4 -Methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-phenylthiophenyldiphenyl Sulfonium hexafluorophosph 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate, 1- (2-naphthoylmethyl) thiolanium hexafluoroantimonate, 1- (2-naphthoylmethyl) thiolanium trifluoroantimonate, 4-hydroxy Examples include -1-naphthyldimethylsulfonium hexafluoroantimonate and 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate.

  Specific examples of the halogen-containing triazine compound contained in the above-described photoacid generator include, for example, 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4,6 -Tris (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethylto-1,3,5-triazine, 2- (4-chlorophenyl) -4,6-bis ( Trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethylto-1,3,5-triazine, 2- (4-methoxy-1-naphthyl)- 4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (benzo [d] [1,3] dioxolan-5-yl) -4,6-bis (trichloromethyl) -1,3 , 5-Triazi 2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3,4,5-trimethoxystyryl) -4,6-bis (trichloromethyl) ) -1,3,5-triazine, 2- (3,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (2,4-dimethoxystyryl)- 4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (2-methoxystyryl) 4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-butoxy Styryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-benzyloxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, Etc.

  Specific examples of the sulfone compound contained in the above-described photoacid generator include diphenyldisulfone, di-p-tolyldisulfone, bis (phenylsulfonyl) diazomethane, bis (4-chlorophenylsulfonyl) diazomethane, and bis (p -Tolylsulfonyl) diazomethane, bis (4-tert-butylphenylsulfonyl) diazomethane, bis (2,4-xylylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, (benzoyl) (phenylsulfonyl) diazomethane, phenylsulfonyl And acetophenone.

  Specific examples of the aromatic sulfonate compound contained in the photoacid generator include α-benzoylbenzyl p-toluenesulfonate (commonly known as benzoin tosylate), β-benzoyl-β-hydroxyphenethyl p-toluenesulfonate. (Commonly known as α-methylol benzoin tosylate), 1,2,3-benzenetriyl trismethanesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, 2-nitrobenzyl p-toluenesulfonate, 4-nitrobenzyl p-toluene And sulfonates.

  Specific examples of the sulfonate compound of N-hydroxyimide contained in the above-mentioned photoacid generator include N- (phenylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) succinimide, N- (p -Chlorophenylsulfonyloxy) succinimide, N- (cyclohexylsulfonyloxy) succinimide, N- (1-naphthylsulfonyloxy) succinimide, n- (benzylsulfonyloxy) succinimide, N- (10-camphorsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) -5-norbornene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphth Ruimido, N-(10- camphorsulfonic sulfonyloxy) naphthalimide, and the like.

  Of the various photoacid generators described above, sulfonium salts are preferred. In particular, triphenylsulfonium trifluoromethanesulfonate; sulfone compounds, particularly bis (4-tert-butylphenylsulfonyl) diazomethane and bis (cyclohexylsulfonyl) diazomethane are preferred.

  The above-mentioned photoacid generators may be used alone or in combination of two or more. There is no restriction | limiting in particular as a compounding ratio of a photo-acid generator, Although it can select suitably according to the objective, 0.1-30 mass parts is preferable with respect to 100 mass parts of hyperbranched polymers of this invention. A more preferable blending ratio of the photoacid generator is 0.1 to 10 parts by mass.

  The acid diffusion inhibitor contained in the resist composition is a component that controls the diffusion phenomenon of the acid generated from the acid generator upon exposure in the resist film and suppresses an undesirable chemical reaction in the non-exposed region. There is no particular limitation. The acid diffusion inhibitor contained in the resist composition can be appropriately selected from known acid diffusion inhibitors according to the purpose.

  Examples of the acid diffusion inhibitor contained in the resist composition include a nitrogen-containing compound having one nitrogen atom in the same molecule, a compound having two nitrogen atoms in the same molecule, and three nitrogen atoms in the same molecule. Examples thereof include polyamino compounds and polymers, amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds.

  Examples of the arsenic-containing compound having one nitrogen atom in the same molecule mentioned as the acid diffusion inhibitor include mono (cyclo) alkylamine, di (cyclo) alkylamine, and tri (cyclo) alkylamine. , Aromatic amines, and the like. Specific examples of the mono (cyclo) alkylamine include n-hexylamine, n-hexylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine, and the like.

  Examples of the di (cyclo) alkylamine contained in the nitrous acid compound having one nitrogen atom in the same molecule include di-n-butylamine, di-n-benzylamine, di-n-hexylamine, di- Examples include n-hebutylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, and the like.

  Examples of the tri (cyclo) alkylamine contained in the nitrous acid compound having one nitrogen atom in the same molecule include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-benzylamine, Examples include tri-n-hexylamine, tri-n-hexylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, cyclohexyldimethylamine, methyldicyclohexylamine, and tricyclohexylamine.

  Examples of the aromatic amine contained in the arsenic compound having one nitrogen atom in the same molecule include aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4 -Methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, and the like.

  Examples of the nitrogen-containing compound having two nitrogen atoms in the same molecule mentioned as the acid diffusion inhibitor include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexa Methylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4- Hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene Zen, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, and the like.

  Examples of the polyamino compound or polymer having 3 or more nitrogen atoms in the same molecule mentioned as the acid diffusion inhibitor include polyethyleneimine, polyallylamine, and N- (2-dimethylaminoethyl) acrylamide. Coalescence, etc.

  Examples of the amide group-containing compound mentioned as the acid diffusion inhibitor include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, and Nt-butoxy. Carbonyl di-n-decylamine, Nt-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, N, N- Di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4, -diaminodiphenylmethane, N, N '-Di-t-butoxycarbonylhexamethylenediamine, N, N, N'N'-tetra t-butoxycarbonylhexamethylenediamine N, N′-di-t-butoxycarbonyl-1,7-diaminohexane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N ′ -Di-t-butoxycarbonyl-1,9-diaminononane, N, N, -di-t-butoxycarbonyl-1,10-diaminodecane, N, N, -di-t-butoxycarbonyl-1,12-diamino Dodecane, N, N, -di-t-butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt- Butoxycarbonyl-2-phenylbenzimidazole, formamide, N-methylformamide, N, N-dimethylformua De, acetamide, N- methylacetamide, N, N- dimethylacetamide, propionamide, benzamide, pyrrolidone, N- methylpyrrolidone, and the like.

  Specific examples of the urea compound mentioned as the acid diffusion inhibitor include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethyl. Examples include urea, 1,3-diphenylurea, tri-n-butylthiourea, and the like.

  Specific examples of the nitrogen-containing heterocyclic compound mentioned as the acid diffusion inhibitor include, for example, imidazole, 4-methylimidazole, 4-methyl-2-phenylimigzole, benzimidazole, 2-phenylbenze. Imidazole, pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinic acid Amide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, piverazine, 1- (2-hydroxyethyl) piverazine, pyrazine, pyrazole, viridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2- Propanediol, morpholy , 4-methylmorpholine, 1,4 Jimechipiberajin, 1,4-diazabicyclo [2.2.2] octane, and the like.

  Said acid diffusion inhibitor can be used individually or in mixture of 2 or more types. As a compounding quantity of said acid diffusion inhibitor, 0.1-1000 mass parts is preferable with respect to 100 mass parts of photo-acid generators. A more preferable blending amount of the acid diffusion inhibitor is 0.5 to 10 parts by mass with respect to 100 parts by mass of the photoacid generator. In addition, there is no restriction | limiting in particular as a compounding quantity of said acid diffusion inhibitor, According to the objective, it can select suitably.

  As the surfactant contained in the resist composition, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester nonionic surfactant, fluorine-based surfactant, Examples thereof include silicon-based surfactants. The surfactant contained in the resist composition is not particularly limited as long as it has a function of improving coatability, striation, developability, etc., and is appropriately selected from known ones according to the purpose. be able to.

  Specific examples of the polyoxyethylene alkyl ether listed as the surfactant contained in the resist composition include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl. Ether, etc. Examples of the polyoxyethylene alkylallyl ether listed as the surfactant contained in the resist composition include polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, and the like.

  Specific examples of the sorbitan fatty acid ester exemplified as the surfactant contained in the resist composition include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, And sorbitan tristearate. Nonionic surfactants of polyoxyethylene sorbitan fatty acid esters mentioned as surfactants included in the resist composition include, for example, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate , Polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, and the like.

  Specific examples of the fluorosurfactant listed as the surfactant contained in the resist composition include F-top EF301, EF303, and EF352 (manufactured by Shin-Akita Kasei Co., Ltd.), MegaFuck F171 and F173. , F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Florard FC430, FC431 (Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SX102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.).

  Examples of the silicon-based surfactant listed as the surfactant contained in the resist composition include organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The various surfactants described above can be used alone or in admixture of two or more. As a compounding quantity of the various surfactant mentioned above, 0.0001-5 mass parts is preferable with respect to 100 mass parts of hyperbranched polymers produced | generated using the manufacturing method concerning this invention, for example. The more preferable compounding amount of the various surfactants described above is 0.0002 to 2 parts by mass with respect to 100 parts by mass of the hyperbranched polymer produced using the production method according to the present invention. In addition, there is no restriction | limiting in particular as compounding quantity of various surfactant mentioned above, According to the objective, it can select suitably.

  Other components included in the resist composition include, for example, a sensitizer, a dissolution controller, an additive having an acid dissociable group, an alkali-soluble resin, a dye, a pigment, an adhesion aid, an antifoaming agent, a stabilizer, And antihalation agents. Specific examples of sensitizers listed as other components contained in the resist composition include, for example, acetophenones, benzophenones, naphthalenes, biacetyl, eosin, rose bengal, bilenes, anthracenes, and phenothiazines. , Etc. As the above sensitizer, it absorbs radiation energy and transmits the energy to the photoacid generator, thereby increasing the amount of acid generated and improving the apparent sensitivity of the resist composition. If it has an effect, there will be no restriction | limiting in particular. Said sensitizer can be used individually or in mixture of 2 or more types.

  Specific examples of the dissolution control agent exemplified as the other component contained in the resist composition include polyketones and polyspiroketals. There are no particular limitations on the dissolution control agent listed as the other component contained in the resist composition as long as it can more appropriately control the dissolution contrast and dissolution rate when used as a resist. The dissolution control agents listed as other components contained in the resist composition can be used alone or in admixture of two or more.

  Specific examples of the additive having an acid-dissociable group listed as other components included in the resist composition include, for example, t-butyl 1-adamantanecarboxylate, t-butoxycarbonylmethyl 1-adamantanecarboxylate. 1,3-adamantane dicarboxylic acid di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, deoxycholic acid t- Butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-fetoxyethyl, deoxycholic acid 2-cyclohexyloxyethyl, deoxycholic acid 3-oxocyclohexyl, deoxycholic acid tetrahydropyranyl, deoxycholic acid mevalonolactone Esters, lithocols tert-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester, etc. It is done. The above additives having various acid dissociable groups can be used alone or in admixture of two or more. The additive having various acid dissociable groups is not particularly limited as long as it further improves dry etching resistance, pattern shape, adhesion to the substrate, and the like.

  Specific examples of the alkali-soluble resin listed as the other component contained in the resist composition include poly (4-hydroxystyrene), partially hydrogenated poly (4-hydroxystyrene), and poly (3-hydroxy). Styrene), poly (3-hydroxystyrene), 4-hydroxystyrene / 3-hydroxystyrene copolymer, 4-hydroxystyrene / styrene copolymer, novolac resin, polyvinyl alcohol, polyacrylic acid and the like.

  The weight average molecular weight (Mw) of the alkali-soluble resin is usually 1,000 to 1,000,000, preferably 2,000 to 100,000. Said alkali-soluble resin can be used individually or in mixture of 2 or more types. The alkali-soluble resin mentioned as the other component contained in the resist composition is not particularly limited as long as it improves the alkali solubility of the resist composition of the present invention.

  The dyes or pigments listed as other components contained in the resist composition make the latent image in the exposed area visible. By visualizing the latent image of the exposed portion, the influence of halation during exposure can be mitigated. Moreover, the adhesion assistant mentioned as another component contained in a resist composition can improve the adhesiveness of a resist composition and a board | substrate.

  Specific examples of the solvent listed as the other component contained in the resist composition include ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionates, alkyl 3-alkoxypropions, Other solvents are mentioned. Solvents listed as other components contained in the resist composition are not particularly limited as long as the other components contained in the resist composition can be dissolved, for example, although those that can be used safely in the resist composition. It can be suitably selected from the inside.

  Specific examples of ketones contained in the solvents listed as other components contained in the resist composition include methyl isobutyl ketone, methyl ethyl ketone, 2-butanone, 2-pentanone, 3-methyl-2-butanone, Examples include 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3-dimethyl-2-butanone, 2-hebutanone, and 2-octanone.

  Specific examples of the cyclic ketone contained in the solvent mentioned as the other component contained in the resist composition include cyclohexanone, cyclopentanone, 3-methylcyclopentanone, 2-methylcyclohexanone, and 2,6. -Dimethylcyclohexanone, isophorone, etc. are mentioned.

  Specific examples of the propylene glycol monoalkyl ether acetate contained in the solvent mentioned as the other component contained in the resist composition include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono- n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl ether acetate, propylene glycol mono-i-butyl ether acetate, propylene glycol mono-SeC-butyl ether acetate, propylene glycol mono-t-butyl ether And acetate.

  Specific examples of the alkyl 2-hydroxypropionate contained in the solvent listed as the other component contained in the resist composition include, for example, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-hydroxy N-propyl propionate, i-propyl 2-hydroxypropionate, n-butyl 2-hydroxypropionate, i-butyl 2-hydroxypropionate, sec-butyl 2-hydroxyarobionate, t-hydroxy-2-hydroxypropionate Butyl, etc.

  Examples of the alkyl 3-alkoxypropionate contained in the solvent mentioned as the other component contained in the resist composition include methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3 -Ethyl ethoxypropionate, etc.

  Examples of the other solvent included in the solvent listed as the other component included in the resist composition include n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, and ethylene glycol. Monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol Monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n- Propyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy- Methyl 3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl propylate, ethyl acetate, n-acetate -Propyl, n-butyl acetate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, Diethyl ether, di-n-hexyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, γ-ptyrolactone, toluene, xylene, caproic acid, caprylic acid, octane, decane, 1-octanol, 1-nonanol, benzyl alcohol, Examples include benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, ethylene carbonate, propylene carbonate, and the like. Said solvent can be used individually or in mixture of 2 or more types.

  As described above, according to the method for synthesizing the core-shell hyperbranched polymer or star polymer according to the embodiment, surface smoothness and alkali solubility that can be used as a polymer material for nanofabrication centered on optical lithography. It is possible to synthesize a hyperbranched polymer and a star polymer with improved s. According to such a resist composition containing a core-shell hyperbranched polymer or a star polymer, the photoresist can be subjected to patterning by developing after being exposed in a pattern.

  The resist composition can correspond to electron beams, deep ultraviolet (DUV), and extreme ultraviolet (EUV) light sources whose surface smoothness is required on the nano order, and can form fine patterns for manufacturing semiconductor integrated circuits. . Thus, the resist composition containing the core-shell hyperbranched polymer produced using the production method according to the present invention is suitable in various fields using a semiconductor integrated circuit produced using a light source that emits light having a short wavelength. Can be used.

  Further, in the semiconductor integrated circuit manufactured using the resist composition containing the hyperbranched polymer of the embodiment, when it is exposed and heated during manufacturing, dissolved in an alkali developer, and then washed by washing, There is almost no unmelted residue on the exposed surface, and a substantially vertical edge can be obtained. As a result, the performance is stabilized, and a fine semiconductor integrated circuit corresponding to an electron beam, a deep ultraviolet (DUV), and an extreme ultraviolet (EUV) light source can be obtained.

  Hereinafter, the above-described embodiment according to the present invention will be specifically clarified by using the following examples. In addition, this invention is not limited at all by the Example shown below.

  The synthesis of the core-shell hyperbranched polymer of Example 1 will be described. In the synthesis of the core-shell hyperbranched polymer of Example 1, 2-benzoyloxy-1 (2,2,6,6-tetramethyl-1-piperidinyloxy) -1- (4 was prepared according to US Pat. No. 6,194,481. -Vinylphenyl) ethane was synthesized.

(Synthesis Example 1)
In a 200 mL flask equipped with a stirrer, a reflux condenser and a nitrogen inlet tube, 1.56 g of 2,2,6,6-tetramethylpiperidine-1-oxy, 15 g of 1,4-divinylbenzene, 1.86 g of benzoyl peroxide The nitrogen gas was introduced from the nitrogen introduction tube while stirring. After introducing nitrogen gas, the inside of the flask was stirred at 95 ° C. for 3.5 hours.

  After stirring, the solvent was distilled off from the stirred solution, and the residue was purified by silica gel chromatography. As a developing solvent in silica gel chromatography, a mixed solution of methylene chloride / hexane = 1/1 was used. As a result, 2-benzoyloxy-1 (2,2,6,6-tetramethyl-1-piperidinyloxy) -1- (4-vinylphenyl) ethane was obtained. The yield was 40%.

Example 1
To a 200 mL flask equipped with a stirrer, a reflux condenser, and a nitrogen introduction tube, 67 g of toluene and 0.82 g of 2,2′-azobisisobutyronitrile were introduced, and nitrogen gas was introduced from the nitrogen introduction tube while stirring. . 2-Benzoyloxy-1 (2,2,6,6-tetramethyl-1-piperidinyloxy) -1- (4-vinylphenyl) ethane (10 g) was added dropwise over 1 hour. Stir for 180 minutes. After stirring, 267 g of toluene, 1.06 g of acrylic acid and 10.71 g of t-butyl acrylate were added and stirred at 120 ° C. for 300 minutes. After stirring, 3000 g of ultrapure water was added to the stirred reaction mixture to reprecipitate the solid content. The solid content obtained by reprecipitation was obtained as the core-shell hyperbranched polymer of Example 1. The yield of the core-shell hyperbranched polymer of Example 1 was 8.7 g (yield 40%), and the weight average molecular weight was 6,000. The degree of branching (Br) was 0.32.

(Example 2)
Polymerization was conducted in the same manner as in Example 1 except that 1.32 g of acrylic acid and 5.00 g of t-butyl acrylate were used. The yield of the core-shell hyperbranched polymer of Example 2 was 6.5 g ( The yield was 40%) and the weight average molecular weight was 6,000. The degree of branching (Br) was 0.31.

(Example 3)
Polymerization was performed in the same manner as in Example 1 except that 1.1 g of acrylic acid and 2.74 g of t-butyl acrylate were used. The yield of the core-shell hyperbranched polymer of Example 3 was 5.5 g ( The yield was 40%) and the weight average molecular weight was 6,000. The degree of branching (Br) was 0.35.

Example 4
Polymerization was conducted in the same manner as in Example 1 except that 7.27 g of vinyl benzoic acid and 10.04 g of t-butyl vinyl benzoate were used. The yield of the core-shell hyperbranched polymer of Example 4 was 12. It was 3 g (yield 45%), and the weight average molecular weight was 7,000. The degree of branching (Br) was 0.34.

(Example 5)
Subsequently, the synthesis of the star polymer of Example 5 will be described. In the synthesis of the star polymer of Example 5, 84 g of toluene, 0.78 g of acrylic acid, 7.9 g of t-butyl acrylate, 2, 2, and 2, were added to a 200 mL flask equipped with a stirrer, a reflux condenser, and a nitrogen introduction tube. 0.47 g of 6,6-tetramethyl-1-piperidinyloxy and 0.17 g of 2,2′-azobisisobutyronitrile were introduced, and nitrogen gas was introduced from a nitrogen introduction tube while stirring. After introducing nitrogen gas, the inside of the flask was stirred at 120 ° C. for 120 minutes.

  After stirring, 1.3 g of divinylbenzene and 1.07 g of ethylstyrene were added to the stirred solution, and the mixture was stirred at 120 ° C. for 60 minutes. After stirring, 150 g of methanol was added to the stirred reaction mixture to reprecipitate the solid content. The solid content obtained by reprecipitation was obtained as the star polymer of Example 5. The yield of the star branch polymer of Example 5 was 3.9 g (35% yield). The weight average molecular weight by GPC was 10,000, and the absolute molecular weight by MALLS was 40,000.

(Example 6)
Next, the synthesis of the star polymer of Example 6 will be described. In the synthesis of the star polymer of Example 6, in a 200 mL flask equipped with a stirrer, a reflux condenser and a nitrogen introduction tube, 86 g of toluene, 0.97 g of acrylic acid, 3.69 g of tert-butyl acrylate, 2,2, 0.83 g of 6,6-tetramethyl-1- (1-phenylethoxy) -4-piperidinol was added, and nitrogen gas was introduced from a nitrogen introduction tube while stirring. After introducing nitrogen gas, the inside of the flask was stirred at 120 ° C. for 60 minutes.

  After stirring, 1.3 g of divinylbenzene and 1.07 g of ethylstyrene were added to the stirred solution, and the mixture was stirred at 120 ° C. for 60 minutes. After stirring, 150 g of methanol was added to the stirred reaction mixture to reprecipitate the solid content. The solid content obtained by reprecipitation was obtained as the star polymer of Example 6. The yield of the star polymer of Example 6 was 2.4 g (yield: 34%). The weight average molecular weight by GPC was 10,000, and the absolute molecular weight by MALLS was 40,000.

(Example 7)
Next, the synthesis of the star polymer of Example 7 will be described. In the synthesis of the star polymer of Example 7, in a 200 mL flask equipped with a stirrer, a reflux condenser and a nitrogen introduction tube, 86 g of toluene, 5.37 g of vinyl benzoic acid, 4.65 g of t-butyl vinyl benzoate, 2, Add 0.58 g of 2,6,6-tetramethyl-1- (1-phenylethoxy) -4-piperidinol and 3.3 mg of 2,2,6,6-tetramethyl-1-piperidinyloxy and stir. However, nitrogen gas was introduced from the nitrogen introduction tube. After introducing nitrogen gas, the inside of the flask was stirred at 120 ° C. for 60 minutes.

  After stirring, 1.3 g of divinylbenzene and 1.07 g of ethylstyrene were added to the stirred solution, and the mixture was stirred at 120 ° C. for 60 minutes. After stirring, 150 g of methanol was added to the stirred reaction mixture to reprecipitate the solid content. The solid content obtained by reprecipitation was obtained as the star polymer of Example 7. The yield of the star polymer of Example 5 was 4.9 g (yield 40%). The weight average molecular weight by GPC was 12,000, and the absolute molecular weight by MALLS was 45,000.

(Preparation of resist composition)
The preparation of the resist composition using the hyperbranched polymer or the star polymer obtained in Examples 1 to 7 will be described. First, trace metals in the polymer are removed from the hyperbranched polymer or star polymer obtained in Examples 1 to 7 by the following method.

(Metal cleaning)
When washing the metal, a solution obtained by dissolving 6 g of the above-described core-shell hyperbranched polymer or star polymer in 100 g of methyl isobutyl ketone is combined with 50 g of a 3% by mass oxalic acid aqueous solution and 50 g of a 1% by mass hydrochloric acid aqueous solution, and vigorously for 30 minutes. Stir. After stirring, the organic layer was taken out from the stirred solution, and 50 g of a 3% by mass oxalic acid aqueous solution and 50 g of a 1% by mass hydrochloric acid aqueous solution were again combined with the taken out organic layer and stirred vigorously for 30 minutes. After repeating this operation 5 times in total, the operation of combining the organic layer and 100 g of ultrapure water and stirring vigorously for 30 minutes was repeated 3 times. The solvent was distilled off from the finally obtained organic layer, and the amount of contained metal was measured by atomic absorption. As a result, the content of copper, sodium, iron, and aluminum in any polymer was 10 ppb or less.

(Preparation of resist composition)
The resist composition using the hyperbranched polymer or star polymer obtained in the above-described Examples 1 to 7 is 4.0% by mass of the hyperbranched polymer or star polymer from which trace metals have been removed, as a photoacid generator. A propylene glycol monomethyl acetate (PEGMEA) solution containing 0.16% by mass of triphenylsulfonium trifluoromethanesulfonate was prepared by filtering with a filter having a pore diameter of 0.45 μm.

  The adjusted resist composition is spin-coated on a silicon wafer, and the silicon wafer coated with the adjusted resist composition is heat-treated at 90 ° C. for 1 minute to evaporate the solvent contained in the adjusted resist composition. Then, a thin film having a thickness of 100 nm was formed on the silicon wafer after evaporation of the solvent.

(UV irradiation sensitivity)
Next, the ultraviolet irradiation sensitivity of the thin film formed on the silicon wafer will be described. The ultraviolet irradiation sensitivity of the thin film formed on the silicon wafer was measured by the following method. When measuring the ultraviolet irradiation sensitivity, a discharge tube type ultraviolet irradiation device (manufactured by Ato Co., Ltd., DF-245 type DonaFix) was used as a light source.

In measuring the ultraviolet irradiation sensitivity, a sample thin film having a thickness of about 100 nm formed on a silicon wafer was irradiated with ultraviolet rays having a wavelength of 245 nm. The ultraviolet rays were applied to a rectangular portion of 10 mm long × 3 mm wide of the thin film formed on the silicon wafer. At the time of irradiation of ultraviolet rays, changing the amount of energy of ultraviolet light irradiated in the range from 0 mJ / cm ² of 50 mJ / cm ^2.

  The silicon wafer after ultraviolet irradiation was heat-treated at 100 ° C. for 4 minutes, and the silicon wafer after heat treatment was immersed in a 2.4% by weight aqueous solution of tetramethylammonium hydroxide (TMAH) at 25 ° C. for 2 minutes. And developed. After development, the silicon wafer was washed with water and dried. The film thickness after drying was measured with a thin film measuring apparatus F20 manufactured by Filmetics Co., Ltd., and the irradiation energy value (sensitivity) at which the film thickness after development was zero was measured. The results are shown in Table 1.

  As shown above, it can be seen that the core-shell hyperbranched polymer and the star polymer obtained by the present invention exhibit good sensitivity.

Claims (8)

A core-shell hyperbranched polymer synthesis method for synthesizing a core-shell hyperbranched polymer via a living radical polymerization of monomers,
A polymerization step of performing the living radical polymerization using an initiator monomer for initiating the living radical polymerization;
A shell part forming step of forming a polymer part synthesized by the living radical polymerization as a core part and forming a shell part containing an acid-decomposable group and an acid group at the end of the core part;
A method for synthesizing a core-shell hyperbranched polymer, comprising: The polymerization step includes
The method for synthesizing a core-shell hyperbranched polymer according to claim 1, wherein the living radical polymerization is performed according to a radical polymerization method using a nitroxyl radical as a key intermediate. A method of synthesizing a star polymer through living radical polymerization of monomers,
The polymer synthesized by the above living radical polymerization is used as the arm part, and the arm part is coupled to each other by adding a compound having two or more vinyl groups during or after the polymerization to form the core part. A method for synthesizing a star polymer comprising a core part forming step.   4. The method for synthesizing a star polymer according to claim 3, wherein a polymer synthesized by the living radical polymerization performed according to a radical polymerization method using a nitroxyl radical as a key intermediate is used as an arm portion.   A hyperbranched polymer synthesized according to the method for synthesizing a core-shell hyperbranched polymer according to any one of claims 1 to 4.   A resist composition comprising the core-shell hyperbranched polymer according to claim 5.   A pattern is formed with the resist composition according to claim 6.   A method for producing a semiconductor integrated circuit, comprising a step of forming a pattern using the resist composition according to claim 6.