JP2009144059A - Core-shell type hyperbranched polymer, resist composition, method for producing semiconductor device and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a micropattern for the production of a semiconductor device such as a super LSI by improving the adhesiveness, sensitivity and surface smoothness. <P>SOLUTION: A core-shell type hyperbranched polymer is formed by attaching a shell part having a region to increase the solubility in an alkali developing liquid by the action of an acid to a terminal of a core part having a structure derived from a hyperbranched polyol. The hyperbranched polyol is composed of a branched polyether polyol, a branched polyester polyol and a branched polyamide polyester polyol. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a core-shell hyperbranched polymer, a resist composition, a semiconductor device manufacturing method, and a semiconductor device.

  Conventionally, in the manufacture of semiconductor devices such as LSI and memory, fine processing by lithography using a resist composition has been performed. In recent years, with the higher integration and higher capacity of devices, ultra-fine processing in the nanometer region has been required, and the exposure light source used in the lithography process has been shortened. Currently, for example, KrF excimer laser light (wavelength 248 nm) or ArF excimer laser light (wavelength 193 nm) is used as an exposure light source used in the lithography process.

  Further, electron beams and EUV light (wavelength: 13.5 nm) are promising as exposure light sources used in lithography processes that perform microfabrication of 32 nm or less. Known resist compositions that enable microfabrication include chemically amplified resist compositions containing a base polymer having a transparent chemical structure for each light source and an acid generator that generates an acid upon exposure. . As the base polymer applied to the chemically amplified resist composition, for example, when an exposure light source that emits KrF excimer laser light is used in the lithography process, a polymer having a novolac-type polyphenol as a basic skeleton (for example, the following patent document) 1).

  As a base polymer applied to the chemically amplified resist composition, for example, when an exposure light source that emits ArF excimer laser light is used in the lithography process, poly (meth) acrylic acid ester may be mentioned (for example, Patent Document 2 below). reference.). As a base polymer applied to the chemically amplified resist composition, for example, when an exposure light source that emits F2 excimer laser light (wavelength 157 nm) is used in the lithography process, a polymer into which fluorine atoms (perfluoro structure) are introduced may be mentioned. (For example, see Patent Document 3 below.)

  In recent years, when the above-described various base polymers are applied to a resist composition used when forming an ultrafine pattern having a thickness of 32 nm or less, the unevenness of the pattern side wall using line edge roughness as an index has become a problem. For example, in order to form an ultrafine pattern by performing electron beam or extreme ultraviolet (EUV) exposure on a conventional resist composition mainly composed of PMMA (polymethyl methacrylate) and PHS (polyhydroxystyrene) It has been pointed out that it becomes a problem to control the surface smoothness at the nano level (see, for example, Non-Patent Document 1 below).

  Conventionally, in order to reduce line edge roughness, the importance of controlling the diffusion of acid generated by exposure from an acid generator has been shown, and the effectiveness of polymeric acid generators has been reported (for example, the following non-patent patents) See reference 2.) Conventionally, a base polymer having an acid generator structure bonded to a polymer skeleton has been disclosed (see, for example, Patent Documents 4 to 9 and Non-Patent Document 3 below). For the various base polymers described above, only examples of linear polymers are described.

  The unevenness of the pattern side wall in the lithography process is considered to be due to the association of linear polymers constituting the resist used in the lithography process, and there have been many reports on techniques for suppressing polymer molecular assembly. (For example, see Non-Patent Document 4 below.) Non-Patent Document 4 reports that, for example, the introduction of a crosslinked structure into a linear polymer is effective as a means for improving the surface smoothness of a positive electron beam resist.

Examples of branched polymers that have improved line edge roughness compared to linear polymers include resist compositions containing polymers in which a linear phenol derivative main chain is branched and linked with chloromethylstyrene (for example, the following patent documents) 10, 11)), and resist compositions containing a star-shaped branched polymer in which a plurality of linear polymer chains are bonded to lower alkyl molecules (for example, see Patent Documents 12 to 14 below). The exposure sensitivity of these branched polymers is as low as several tens of mJ / cm ² .

  With regard to the hyperbranching of styrene derivatives, which are the main polymer of lithography, it has been reported that the degree of branching and weight average molecular weight of living chloromethylstyrene can be controlled by living radical polymerization (for example, the following) (See Patent Documents 15 and 16 and Non-Patent Documents 5 and 6 below.) Conventionally, a base polymer having an acid-decomposable group at the molecular end of highly branched polychloromethylstyrene has been disclosed (see, for example, Patent Document 17 below).

Japanese Patent Laid-Open No. 2004-231858 JP 2004-359929 A JP 2005-91428 A JP 20064531 JP 2006-171656 A JP 2006-178317 A JP 2006-215526 A JP 2006-259508 A JP 2006-259509 A Japanese Patent Application Laid-Open No. 2000-347412 JP 2001-324813 A JP-A-2005-53996 JP-A-2005-70742 JP 2006-4550 A Special Table 2000-500516 JP 2000-514479 A WO2005 / 061566 Franco Cerrina, Vac. Sci. Tech. B, 19, 62890 (2001) Michael. D. Stewart, J.M. Vac. Sci. Tech. B, 20, 2946 (2001) Takeo Watanabe, J.A. Photopolym. Sci. Technol. , 19, 521 (2006) Toru Yamaguchi, Jpn. J. et al. Appl. Phys. , 38, 7114 (1999) Krzysztof Matyjaszewski, Macromolecules 29, 1079 (1996) Jean M. J. et al. Frecht, J .; Poly. Sci. 36, 955 (1998)

  However, in the techniques described in Patent Documents 15 and 16 and Non-Patent Documents 5 and 6, the molecular design for imparting the workability by exposure necessary for the resist has not been made so far. There was a problem.

  The present invention has been made in view of the above circumstances, and is suitable for nanofabrication centered on optical lithography, particularly suitable for electron beam and EUV lithography, and has a core-shell hyper-type with improved adhesion, sensitivity, and surface smoothness. An object of the present invention is to obtain a resist composition that includes a branch polymer as a base polymer and can form a fine pattern for manufacturing a semiconductor device such as a VLSI.

  As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. That is, in order to solve the above-described problems and achieve the object, the core-shell hyperbranched polymer according to the present invention is a core-shell hyperbranched polymer including a core portion and a shell portion provided at the end of the core portion. The core portion has a structure derived from a hyperbranched polyol, and the shell portion has a portion where the solubility in an alkali developer is increased by the action of an acid.

  In the core-shell hyperbranched polymer according to the present invention, in the above, the hyperbranched polyol is preferably composed of a branched polyether polyol.

  In the core-shell hyperbranched polymer according to the present invention, the hyperbranched polyol is preferably composed of a branched polyester polyol.

  In the core-shell hyperbranched polymer according to the present invention, in the above, the hyperbranched polyol is preferably composed of a branched polyamide polyester polyol.

  The resist composition according to the present invention includes the core-shell hyperbranched polymer described above.

  A method for manufacturing a semiconductor device according to the present invention is characterized in that a resist pattern is formed on a semiconductor substrate using the resist composition.

  The semiconductor device according to the present invention is characterized in that a resist pattern is formed on a semiconductor substrate by the resist composition.

  According to the core-shell hyperbranched polymer, the resist composition, the semiconductor device manufacturing method, and the semiconductor device according to the present invention, EUV (extreme ultraviolet) lithography or electron beam lithography, which is one of nanofabrication centered on photolithography, is used. Therefore, it is possible to provide a semiconductor device such as a core-shell hyperbranched polymer and a VLSI that can be used as a polymer material for improving the sensitivity and surface smoothness and is excellent in fine pattern formation.

  Exemplary embodiments of a core-shell hyperbranched polymer, a resist composition, a semiconductor device manufacturing method, and a semiconductor device according to the present invention will be explained below in detail with reference to the accompanying drawings.

<Core part>
The structure of the hyperbranched polyol that forms the core of the core-shell hyperbranched polymer of the present invention is preferably a branched polyether polyol, a branched polyester polyol, or a branched polyamide polyol.

  A branched polyether polyol is obtained by reacting a polyol with a hydroxy epoxy or a hydroxy cyclic carbonate, has 3 branches or more, has 3 or more hydroxyl groups, and has a molecular weight (Mw) of 500 to 10,000. Is preferred.

  The reaction of a polyol with a hydroxy epoxy or a hydroxy cyclic carbonate can be synthesized by, for example, a method described in Alexander Sun, Ruff Hanselmann, Holger Frey and Rol Mulhaupt, Macromolecules 1999, 32, 4240-4246.

  The polyol can be any compound having 2 to 20 hydroxyl groups and is used as a hydrogen active starting compound. More preferably, it has 2 to 10 hydroxyl groups and a molecular weight of 50 to 3000.

  Examples of the polyol include triethylene glycol, polyethylene glycol, tripropylene glycol, polypropylene glycol, hexamethylene glycol, bisphenol A, trimethylolpropane, tetramethylene glycol, neopentyl glycol, trimethylolethane, glycerol, pentaerythritol, hexanetriol, Sorbitol, anthrorobin, 4,4 ′, 4 ″ -methylidyne trisphenol, 1,3,5-tris (4-hydroxyphenyl) benzene, 2,4,6-tris (p-hydroxyphenyl) -4, 6-dimethyl-1-heptene, benzene-1,3,5-triol, benzene-1,2,3-triol, sucrose, decomposed starch, allylglycerol, allyl alcohol, 10-undeceno Is a typical example.

  More preferably, trimethylolpropane, trimethylolethane, glycerol, pentaerythritol, 2,4,6-tris (p-hydroxyphenyl) -4,6-dimethyl-1-heptene, benzene-1,3,5-triol , Benzene-1,2,3-triol.

  The hydroxy epoxy can be any linear, branched or alicyclic hydroxy epoxy. The linear, branched or alicyclic hydroxy epoxy preferably has 1 to 20 epoxy groups and 1 to 20 hydroxyl groups.

  Hydroxyepoxy is, for example, glycidol, tricoviridine, 6,7-epoxy-3,7-dimethyl-1-octen-3-ol, 3-methyl-3-hydroxymethyloxetane, 4,5-epoxydecane-1- All, 2α- (hydroxymethyl) -3β-phenyloxirane, 2-oxiranyl-6-methyl-5-hepten-2-ol, 2,3-epoxy-4-hydroxynonanal, 4-hydroxy-2,3- 2-Methoxyethyl epoxybutanoate, 1-oxiranylethylene glycol, 7-oxabicyclo [4.1.0] heptane-3-methanol, 3-methyl-2,3-epoxy-1-butanol, 4-phenyl -3,4-epoxy-2-butanol, 2,3-epoxy-2-methyl-4-heptanol, 1,2-epoxy Representative examples include -1- (1-hydroxypropyl) cycloheptane and 3,5-dimethyl-2-hydroxy-3,4-epoxy-5-hexenal. More preferred are glycidol, 3-methyl-3-hydroxymethyloxetane, and 4,5-epoxydecan-1-ol.

  The hydroxy cyclic carbonate may be any linear, branched or alicyclic carbonate. It preferably contains an alicyclic carbonate group and a hydroxyl group, and more preferably contains one or more alicyclic carbonate groups and two or more hydroxyl groups.

  Hydroxy cyclic carbonates include, for example, 4- (hydroxymethyl) -1,3-dioxolan-2-one, 4- (hydroxymethyl) -5- (benzyloxymethyl) -1,3-dioxolan-2-one, 1- (4-Ethoxy-3-methoxyphenyl) -1,2,3-trihydroxypropane-2,3-cyclic carbonate, 4,4-dimethyl-5- [1- (4-hydroxyphenyl) ethenyl ] -1,3-dioxolan-2-one, 1-hydroxyhexyl-1,3-dioxolan-2-one, 4- (3-methoxy-4-ethoxyphenyl) -5- (hydroxymethyl) -1,3 -Dioxolan-2-one is a typical example. More preferably, 4- (hydroxymethyl) -1,3-dioxolan-2-one is good. However, the combination of polyol and hydroxy epoxy preferably has a total of 3 or more hydroxyl groups.

  In the reaction of the polyol with the hydroxy epoxy or hydroxy cyclic carbonate, it is preferable to react glycidol with one selected from trimethylolpropane, trimethylolethane, glycerol, and pentaerythritol.

  Examples of the branched polyether polyol include Hyperbranched Polymers molecular weight 2000 (catalog No. PG-2) manufactured by Hyper Polymers, and Hyperbranched Polymers molecular weight 6000 (catalog No. PG-6) manufactured by Hyper Polymers.

  A branched polyester polyol is obtained by reacting a polyol with a di-, tri- or polyhydroxycarboxylic acid, has three or more branches, has three or more hydroxyl groups, and has a molecular weight (Mw) of 500 to 10,000. Is preferred. The reaction between the polyol and di-, tri- or polyhydroxycarboxylic acid can be synthesized, for example, by the method described in JP-T-10-508052.

  The polyol in this case is, for example, triethylene glycol, polyethylene glycol, tripropylene glycol, polypropylene glycol, hexamethylene glycol, bisphenol A, trimethylolpropane, tetramethylene glycol, neopentyl glycol, trimethylolethane, glycerol, pentaerythritol, Hexanetriol, sorbitol, anthrorobin, 4,4 ′, 4 ″ -methylidynetrisphenol, 1,3,5-tris (4-hydroxyphenyl) benzene, 2,4,6-tris (p-hydroxyphenyl) -4,6-dimethyl-1-heptene, benzene-1,3,5-triol, benzene-1,2,3-triol, sucrose, decomposed starch, allylglycerol, allyl alcohol, 10-un Senoru, it can be cited as typical examples.

  More preferably, trimethylolpropane, trimethylolethane, glycerol, pentaerythritol, 2,4,6-tris (p-hydroxyphenyl) -4,6-dimethyl-1-heptene, benzene-1,3,5-triol Benzene-1,2,3-triol is preferred.

  The di, tri or polyhydroxy carboxylic acid can be any linear, branched or cycloaliphatic. Di-, tri- or polyhydroxycarboxylic acids are, for example, dihydroxypropionic acid, lactic acid, dihydroxyglycolic acid, hydroxycaproic acid, hydroxybutanoic acid, hydroxypropionic acid, dihydroxybenzoic acid, caffeic acid, homogentisic acid, mevalonic acid, 3,5 -Dihydroxy-2,6,6-tris (3-methyl-2-butenyl) -4- (3-methyl-1-oxobutyl) -2,4-cyclohexadien-1-one, 2,4-dihydroxy-6 -Methylbenzoic acid, 3,4-dihydroxy-5- (galloyloxy) benzoic acid, 2,3-dihydroxypropyl palmitate, 2- (3,6-dihydroxy-9H-xanthen-9-yl) benzoic acid, 3- (2,4-dihydroxyphenyl) propenoic acid, 1,2-dihydroxy-1,1, - ethane tricarboxylic acid, 2- (4,4-dihydroxy-benzhydryl) benzoic acid, tetrahydro-3,4-dihydroxy-5- (hydroxymethyl) -2-furan carboxylic acid, are representative examples.

  The di-, tri- or polyhydroxycarboxylic acid is more preferably dihydroxypropionic acid, lactic acid, dihydroxyglycolic acid, hydroxycaproic acid, hydroxybutanoic acid, hydroxypropionic acid, or dihydroxybenzoic acid. More preferably, the reaction between the polyol and the di-, tri- or polyhydroxycarboxylic acid is trimethylolpropane and 2,2-dihydroxypropanoic acid.

  Moreover, the branched polyester polyol made from Perstorp Japan can also be used for the branched polyester polyol. For example, the product names Boltorn20, Boltorn30, and Boltorn40 are good examples of branched polyester polyols manufactured by Perstorp Japan. Boltorn 20 has a molecular weight (Mw) 2100, Boltorn 30 has a molecular weight (Mw) 3500, and Boltorn 40 has a molecular weight (Mw) 5100.

  The branched polyamide polyester polyol is obtained by reacting a dicarboxylic acid anhydride with di, tri, or polyhydroxyamine, has 3 or more branches, has 3 or more hydroxyl groups, and has a molecular weight (Mw) of 500 to 10,000. It is preferable that The reaction of dicarboxylic anhydride and di, tri, or polyhydroxyamine can be synthesized, for example, by the method described in JP-T-2002-53254.

  Examples of the dicarboxylic anhydride include succinic anhydride, phthalic anhydride, naphthalic anhydride, 4- (4-methyl-3-pentenyl) -4-cyclohexene-1,2-dicarboxylic anhydride, 2-dimethyl -1,2-cyclopropanedicarboxylic acid anhydride, bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid anhydride, hexahydro-3,6-epoxyphthalic acid anhydride, 3-phenyl -4-cyclohexene-1,2-dicarboxylic acid anhydride, 1,2-cyclohexanedicarboxylic acid anhydride, 3,6-dimethyl-4-cyclohexene-1,2-dicarboxylic acid anhydride, 3,6-dimethyl-1 -Cyclohexene-1,2-dicarboxylic acid anhydride, 3,6-dimethylcyclohexane-1,2-dicarboxylic acid anhydride, 4-methylhexahydrophthalic acid anhydride, , 2'-bibenzoic acid anhydride, 1,2-cyclopropane dicarboxylic acid anhydride, 4-hexene-1,2-dicarboxylic acid anhydride, can be cited as typical examples.

  More preferably, succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride, naphthalic anhydride, 4- (4-methyl-3-pentenyl) -4-cyclohexene-1,2-dicarboxylic anhydride, 2-dimethyl-1,2-cyclopropanedicarboxylic acid anhydride, 4-methylhexahydrophthalic acid anhydride, 2,2'-bibenzoic acid anhydride, 1,2-cyclopropanedicarboxylic acid anhydride, 4-hexene- 1,2-dicarboxylic anhydride is preferred.

  Di, tri or polyhydroxyamines are diisopropanolamine, 2- (2,4,5-trihydroxyphenyl) ethanamine, diethanolamine, 3-aminopropane-1,2-diol, 4- (aminomethyl) -5- Hydroxy-6-methylpyridine-3-methanol, 2- (3,4-dihydroxyphenyl) ethylamine, 2,2-bis (hydroxymethyl) -2-aminoethanol, di (2-hydroxypropyl) amine, 4- ( 2-methylaminoethyl) catechol, 3-hydroxy-α- (aminomethyl) benzyl alcohol, N-ethyl-2- (3-hydroxyphenyl) -2-hydroxyethanamine, 5,6-dihydroxy-1H-indole- 3-Ethanamine, 3- (2-oxo-2-hydroxyethyl) -6 (2-hydroxyethyl) -3,6-diazaoctanedioic acid, bis (3-hydroxypropyl) amine, 1- (3,4-dihydroxyphenyl) -2-aminoethanol, 5,5'-bi (2-amino) Phenol), N- (hydroxymethyl) -2-hydroxy-1-propanamine, and 1,3-bis (2-hydroxyethylamino) -2-propanol are representative examples.

  More preferably, diisopropanolamine, 2- (2,4,5-trihydroxyphenyl) ethanamine, diethanolamine, 3-aminopropane-1,2-diol, 2- (3,4-dihydroxyphenyl) ethylamine, 1- (3,4-Dihydroxyphenyl) -2-aminoethanol and 1,3-bis (2-hydroxyethylamino) -2-propanol are preferred.

  More preferably, the reaction of the dicarboxylic acid anhydride with di-, tri- or polyhydroxyamine may be performed by reacting diisopropanolamine with one selected from succinic anhydride, phthalic anhydride, and hexahydrophthalic anhydride. . Examples of the branched polyamide polyester polyol include trade name HYBRANE manufactured by DSM JAPAN.

<Shell part>
(When the shell is synthesized by living radical polymerization)
When synthesizing a core-shell hyperbranched polymer as a resist compound, when a shell part is provided around a polyol as a core part by living radical polymerization, first, a core part into which an initiating group is introduced is synthesized.

  The initiating group serves as a reaction field for living radical polymerization. By using the initiating group, the monomer and the catalyst are brought close to the initiating group portion, and a living radical polymerization reaction occurs. In addition, about the living radical polymerization using an initiating group, it is the same as that of the well-known general living radical polymerization method.

  In this embodiment mode, a method of introducing bromine (Br) using 2-bromoisobutyryl bromide is used as the introduction of an initiation group for living radical polymerization (ATRP). The initiating group is not limited to bromine (Br), but may be any other halogen element such as fluorine, chlorine and iodine. Of the halogen elements, bromine (Br) and chlorine (Cl) are preferable as the starting group. The halogen used as the initiating group is introduced by reacting with the hydroxyl group of the polyol.

  The solvent used when introducing the initiating group is preferably a dehydrated solvent. For example, dehydrated pyridine, dehydrated diethyl ether, dehydrated tetrahydrofuran and the like can be mentioned. The reaction temperature is preferably 0 to 100 ° C, more preferably 0 to 40 ° C. The reaction time is preferably 0.5 to 24 hours, and more preferably 1 to 12 hours.

  Upon introduction of the acid-decomposable group, living radical polymerization (ATRP) proceeds by reversibly radically dissociating with a transition metal complex as a polymerization catalyst and suppressing bimolecular termination. For example, in living radical polymerization using a copper (I) bipyridyl complex as a polymerization catalyst, an adduct is intermediated while a bromine atom with an initiating group is oxidized to a copper (II) complex. And a methylene radical is generated on the opposite side of the bromine atom (Krzysztof Matyjazewski, Macromolecules 29, 1079 (1996) and Jean MJ Frecht, J. Poly. Sci., 36, 955 (1998). reference). This radical intermediate reacts with another monomer and an ethylenic double bond, and polymerization proceeds. The polymerization solvent is not particularly limited as long as the monomer and the polymerization catalyst are uniformly dissolved or dispersed.

-Shell part introduction process-
In the core-shell hyperbranched polymer of the present invention, the shell portion can be introduced by reacting a core portion were introduced starting group can be synthesized as before mentioned, a common monomer. Specific examples of the monomer will be described later.

  In order to prevent radicals from being affected by oxygen, the shell polymerization is preferably carried out in the presence of nitrogen or an inert gas, or under a flow and oxygen-free conditions. Shell polymerization can be applied to both batch and continuous processes.

  The method for introducing the shell portion into the core portion is a method in which the core portion obtained in the core portion synthesis step is isolated and then introduced using a monomer that forms the shell portion. As the catalyst, a transition metal complex catalyst similar to the catalyst used for the synthesis of the core part, for example, a copper (I-valent) bipyridyl complex is used. A linear addition polymerization is performed by atom transfer radical polymerization with a double bond.

  Specifically, for example, a metal catalyst is previously provided on the inner surface of the reaction kettle, and the hyperbranched polyol and the monomer are dropped into the reaction kettle. Specifically, for example, the monomer for forming the shell portion described above may be dropped into a reaction kettle in which the hyperbranched core polymer is present in advance. As for the monomer, metal catalyst, and solvent used in the shell polymerization, it is preferable to use one that has been sufficiently deoxygenated (degassed) in the same manner as the core polymerization described above.

  As the metal catalyst used in the shell polymerization, for example, a metal catalyst composed of a combination of a transition metal compound such as copper, iron, ruthenium, and chromium and a ligand can be used. Examples of transition metal compounds include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, cuprous oxide, cuprous perchlorate, ferrous chloride, bromide Examples include ferrous iron and ferrous iodide.

  Examples of the ligand include pyridines, bipyridines, polyamines, and phosphines that are unsubstituted or substituted with an alkyl group, aryl group, amino group, halogen group, ester group, or the like. Preferred metal catalysts include, for example, a copper (I) bipyridyl complex composed of copper chloride and a ligand, a copper (I) pentamethyldiethylenetriamine complex, and an iron (II) triphenyl composed of iron chloride and a ligand. A phosphine complex, an iron (II) tributylamine complex, etc. can be mentioned.

  The metal catalyst is preferably used in an amount of 0.01 to 70 mol%, preferably 0.1 to 60 mol%, based on the reaction active point of the hyperbranched core polymer used for shell polymerization. It is more preferable to use it. When the catalyst is used in such an amount, the reactivity can be improved and a core-shell hyperbranched polymer having a suitable degree of branching can be synthesized.

  The method for adding the metal catalyst is not particularly limited, but for example, it can be added all at once before shell polymerization. Further, after the start of polymerization, it may be added in addition according to the degree of deactivation of the catalyst. For example, when the dispersion state in the reaction system of the complex serving as the metal catalyst is not uniform, the transition metal compound may be added to the apparatus in advance, and only the ligand may be added later.

  0-200 degreeC is preferable and, as for the temperature of superposition | polymerization in this invention, 50-150 degreeC is more preferable. The polymerization time is 1 to 30 hours, more preferably 1 to 10 hours. The solvent used for the polymerization is not particularly limited, and the reaction is performed in an inert solvent such as N-methyl-2-pyrrolidone, methyl isobutyl ketone, toluene, xylene, tetrahydrofuran, and anisole. As described above, the core-shell hyperbranched polymer of the present invention can be produced by reacting the core portion with the monomer.

(Deprotection)
Next, deprotection will be described. Upon deprotection, the acid-decomposable group is partially decomposed. In the partial decomposition of the acid-decomposable group, for example, a part of the acid-decomposable group is decomposed into an acid group using an acid catalyst. In the embodiment, the acid group forming step is realized here.

  When part of the acid-decomposable group is decomposed into an acid group using the above-described acid catalyst (the acid-decomposable group is partially decomposed), the acid-decomposable group in the core-shell hyperbranched polymer is Usually, 0.001 to 0.1 equivalent of an acid catalyst is used. When partially decomposing acid-decomposable groups, there is no risk of volatilization by heating and refluxing, and the core-shell hyperbranched polymer after removal of the metal or the core-shell hyperbranched polymer is dissolved regardless of the temperature. A substance that dissolves uniformly in the organic solvent is used as the acid catalyst. In the embodiment, the step of mixing the acid catalyst into the reaction system containing the core-shell hyperbranched polymer is realized.

  Specific examples of the acid catalyst used for deprotection include sulfuric acid, paratoluenesulfonic acid, acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, and the like. Among the various acid catalysts described above, sulfuric acid is more preferable because of good reactivity.

  The organic solvent used for partially decomposing the acid-decomposable group can dissolve the core-shell hyperbranched polymer and the acid catalyst regardless of the temperature, and has compatibility with water. preferable. As an organic solvent used for partially decomposing an acid-decomposable group, 1,4-dioxane, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone and a mixture thereof can be used because of their availability and ease of handling. More preferably, it is selected from the group consisting of Among the various organic solvents described above, the organic solvent used when partially decomposing the acid-decomposable group can be refluxed at a high temperature of 90 ° C. or higher and has high compatibility with water. Is preferred.

  In the synthesis of the core-shell hyperbranched polymer, the reflux at high temperature is indispensable for maximizing the effect of the acid and efficiently performing the acid decomposition. In addition, the compatibility of the organic solvent used in the synthesis of the core-shell hyperbranched polymer with water is an indispensable factor when performing reprecipitation operation by adding excess water to the organic solvent after acid decomposition. The amount of the organic solvent used for deprotection is, for example, 3 to 50 times by mass with respect to the polymer if the core-shell hyperbranched polymer and the acid catalyst after the removal of the trace metal are dissolved. Preferably, it is 5-20 mass times.

  The amount of the organic solvent used for deprotection is not particularly limited to the above-described range as long as the core-shell hyperbranched polymer and the acid catalyst are dissolved. When the amount of the organic solvent with respect to the core-shell hyperbranched polymer is below the above range, the viscosity of the reaction system increases and the handling property is deteriorated. On the other hand, when the amount of the organic solvent with respect to the core-shell hyperbranched polymer after metal removal described above exceeds the above range, it is not preferable from the viewpoint of cost increase.

  The concentration of the core-shell hyperbranched polymer after removal of the metal in the organic solvent used for deprotection is lower than the saturated dissolution concentration of the core-shell hyperbranched polymer at room temperature (25 ° C.) and heating. The highest concentration is preferable among the concentration conditions that significantly increase the viscosity during the reaction and do not affect the stirring. The reaction temperature for deprotection is preferably 50 to 150 ° C, more preferably 70 to 110 ° C. The reaction time for deprotection is preferably 10 minutes to 20 hours, and more preferably 10 minutes to 3 hours.

  The ratio of the acid-decomposable group to the acid group in the core-shell hyperbranched polymer after deprotection is such that 1 to 80 mol% in the monomer containing the acid-decomposable group introduced into the core-shell hyperbranched polymer is deprotected. It is preferably converted to an acid group. When the ratio of the acid-decomposable group to the acid group is in such a range, it is preferable because high sensitivity and efficient alkali solubility after exposure are achieved.

  The ratio between the acid-decomposable group and the acid group in the core-shell hyperbranched polymer after deprotection differs depending on the composition ratio in the resist composition when the core-shell hyperbranched polymer is used as the resist composition. It is not specifically limited to the range mentioned above. The ratio of the acid-decomposable group to the acid group in the core-shell hyperbranched polymer after deprotection can be adjusted by controlling the reaction time.

  The ratio of the acid-decomposable group to the acid group in the core-shell hyperbranched polymer after deprotection is adjusted by appropriately controlling the amount of the acid catalyst used for deprotection, the reaction temperature and reaction time for deprotection, etc. However, it can be adjusted most easily by controlling the reaction time.

  After deprotection, the reaction solution containing the deprotected core-shell hyperbranched polymer is mixed with ultrapure water to precipitate the deprotected core-shell hyperbranched polymer, followed by centrifugation, filtration, and decane. The polymer is separated using a means such as a ration. In order to remove the remaining acid catalyst, it is preferable to wash the polymer by contacting with an organic solvent or water as required.

  As described above, after the monomer is removed, drying is performed. The drying method is not particularly limited, and examples thereof include drying methods such as vacuum drying and spray drying. In drying, it is preferable that the temperature of the environment in which the core-shell hyperbranched polymer from which the monomer has been removed and the core-shell hyperbranched polymer exist (hereinafter referred to as “drying temperature”) be in the range of 10 to 70 ° C. In drying, the drying temperature is more preferably in the range of 15 to 40 ° C.

  In drying, it is preferable to evacuate the environment where the core-shell hyperbranched polymer from which the monomer has been removed is present. The degree of vacuum during drying is preferably 20 Pa or less. The drying time is preferably 1 hour to 20 hours. Note that the degree of vacuum and the drying time during drying are not limited to the above-described values, and are set so that the above-described drying temperature is properly maintained.

(When synthesizing the shell part by radical polymerization)
When a core-shell hyperbranched polymer to be a resist compound is synthesized using radical polymerization, a monomer is first introduced into the hydroxyl group of the polyol described above in order to obtain a structure capable of radical polymerization. The method for introducing the monomer is not particularly limited as long as it can react with the hydroxyl group of the polyol and introduce the monomer.

  There is no particular limitation as long as it is a monomer of an acid halide (acyl halide), but preferably a double bond capable of radical polymerization is introduced by reacting with a hydroxyl group of a polyol using an acid chloride monomer. Make the structure you have. In the example using acid chloride, for example, acrylic acid chloride and the hydroxyl group of polyol are esterified. As a result, a structure in which an acrylic acid monomer is attached to the polyol (pseudonym: polyol acrylic acid body) is obtained. The acid chloride monomer used at this time is not particularly limited, and may be, for example, methacrylic acid chloride or vinyl benzoic acid chloride.

  The reaction temperature for introducing the monomer may be 0 to 200 ° C, and preferably 50 to 150 ° C. A solvent that does not react with acid chloride is used. For example, diethyl ether, benzene, and xylene are mentioned.

  When the shell portion is provided by radical polymerization around the polyol as the core portion, various acid-decomposable groups shown later can be used. Further, the acid-decomposable group used when the shell part is synthesized by radical polymerization is not particularly limited as long as it is a monomer used in normal radical polymerization in addition to various acid-decomposable groups described later. When synthesizing the shell portion by radical polymerization, for example, ATRP (Atom Transfer Radical Polymerization), which is one of living radical polymerization, also uses acrylic acid, methacrylic acid, vinyl benzoic acid, maleic acid and the like which are difficult to polymerize. You can also.

  Examples of the solvent used in the polymerization reaction include a solvent that dissolves the raw material monomer, a solvent that dissolves the polymerization initiator, and a solvent that is put into the reaction vessel. These are those that dissolve the raw material monomer, the polymerization initiator, and the generated polymer. As long as they are not particularly limited, they may be the same or different.

  Specific examples of the solvent include ketones such as acetone, methyl ethyl ketone and methyl amyl ketone; ethers such as tetrahydrofuran, dioxane, glyme and propylene glycol monomethyl ether; esters such as ethyl acetate and ethyl lactate; propylene glycol methyl ether acetate and the like Ether esters; lactones such as γ-butyrolactone, and the like, and these can be used alone or in combination.

  As the radical polymerization initiator, conventionally used azo radical polymerization initiators and organic peroxide radical polymerization initiators can be used.

  Examples of the azo polymerization initiator include 2,2-azobis (2-methyl-N- (1,1-bis (hydroxymethyl) -2-hydroxyethyl) propionamide), 2,2-manufactured by Wako Pure Chemical Industries, Ltd. Azobis (1- (2-hydroxymethyl) -2-imidazolin-2-yl) propane dihydrochloride, 2,2-azobis (2-methyl-N- (2-hydroxyethyl) propionamide), 2,2 ′ -Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] disulfide dihydrate, 2,2'- Azobis (2-methylpropionamidine) dihydrochloride, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamid Gin] hydrate, 2,2′-azobis [2- (2-imidazolidin-2-ylpropane), 2,2′-azobis-1-imino-1-pyrrolidino-2-ethylpropane] dihydrochloride, 2,2′-azobis (4-methoxy-2.4-dimethylvaleronitrile), 2,2′-azobis (2.4-dimethylvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate) ), 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis [N- (2-propenyl) -2-methyl Propionamide], 1, [(cyano-1-methylethyl) azo] formamide, 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobi (N- cyclohexyl-2-methylpropionamide), and the like.

  Among them, 2,2-azobis (2-methyl-N- (1,1-bis (hydroxymethyl) -2-hydroxyethyl) propionamide), 2,2-azobis (1- (2-hydroxymethyl) -2 -Imidazolin-2-yl) propane dihydrochloride, 2,2-azobis (2-methyl-N- (2-hydroxyethyl) propionamide) are preferred.

  Examples of peroxide polymerization initiators include methyl ethyl peroxide, methyl isobutyl peroxide, acetylacetone peroxide, cyclohexanone peroxide, 1,1,3,3-tetramethylbutyl peroxide, cumene hydroperoxide, and t-butyl. Hydroperoxide, isobutyryl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide, benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di- (t -Butylperoxyhexane), 1,3-bis (t-butylperoxyisopropyl) benzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5 di- (t-butyl) Ruoxy) 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 -Butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethyl Xanoate, t-amylperoxy 2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, di-t-butylperoxyhexahydrotetraphthalate, t-amylperoxy3 5,5-trimethylhexanoate, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate, di-butylperoxytrimethyladipate, di-3-methoxybutylperoxy Dicarbonate, di-2-ethylhexylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-isopropylperoxydicarbonate, t-butylperoxyisopropylcarbonate t-butyl peroxy 2-ethylhexyl carbonate, 1,6-bis (t-butylperoxy-carbonitrile Niro yl) hexane, diethylene - bis (t-butylperoxy carbonate, and the like.

  The amount of the polymerization initiator used can be selected from a wide range depending on the raw material monomer used in the polymerization reaction, the type and amount of the chain transfer agent, and the polymerization conditions such as the polymerization temperature and the polymerization solvent. In the polymerization reaction, a chain transfer agent may be used. For example, thiol compounds such as dodecanethiol, mercaptoethanol, mercaptopropanol, mercaptoacetic acid, mercaptopropionic acid can be used alone or in combination. The chain transfer agent may be used after being dissolved in the monomer solution together with the monomer, or may be used after being dissolved in the polymerization initiator solution together with the polymerization initiator.

  Next, a method for producing the shell part synthesis of the two types of core-shell hyperbranched polymers described above will be described. A monomer solution containing a polymerizable monomer as a raw material and a solution containing a polymerization initiator are held in independent storage tanks, and are supplied to a polymerization system continuously or intermittently to produce radical copolymerization. As a result, the reaction can be moderated, and high molecular weight components that adversely affect the resist performance can be eliminated.

  The polymerization temperature is controlled so that the temperature in the system does not decrease due to the supply of the monomer solution and the initiator solution, and is preferably maintained within the set temperature ± 5 ° C, particularly preferably within the set temperature ± 3 ° C. In addition, as a method for suppressing the local temperature change in the polymerization system to be lower, there can be mentioned a method in which the monomer solution is preheated and supplied as described above. A method in which the polymerization temperature is set to be equal to or higher than the boiling point of the polymerization solvent and the reaction is performed under the reflux condition of the polymerization solvent is preferable because the temperature change in the system can be reduced.

  The resist polymer of the present invention obtained by the polymerization reaction is precipitated by dropping the polymerization reaction solution into a poor solvent alone or a mixed solvent of a poor solvent and a good solvent, and further washed as necessary to unreact. Unnecessary substances such as monomers, oligomers, polymerization initiators and reaction residues thereof can be removed and purified.

  The poor solvent is not particularly limited as long as it does not dissolve the polymer. For example, water, alcohols such as methanol and isopropanol, saturated hydrocarbons such as hexane and heptane, and the like can be used. The good solvent is not particularly limited as long as it is a solvent in which the monomer, oligomer, polymerization initiator and residue thereof are dissolved, but the same solvent as the polymerization solvent is preferable in terms of management of the production process. The obtained polymer is desirably dried using reduced pressure drying or the like.

(Ratio of shell part)
The ratio of the acid-decomposable group to the acid group in the core-shell hyperbranched polymer can be adjusted by appropriately controlling the reaction temperature, reaction time, and the like. When the shell portion is synthesized by living radical polymerization, it can be most easily adjusted by controlling the reaction time of the deprotection reaction. When synthesizing the shell part by radical polymerization, it is also possible to change the charging ratio of the monomer having an acid-decomposable group and an acid group.

  The ratio between the acid-decomposable group and the acid group in the core-shell hyperbranched polymer can be appropriately changed depending on the ratio between the core and the shell and the monomer structure used. Compared to the case where a lot of hydrophobic monomers are used, the ratio of acid groups is lower when a lot of hydrophilic monomers are used. Specifically, the ratio of acid groups in the shell portion is preferably 0 to 80%, more preferably 0 to 50%, and most preferably 0 to 30%.

(Monomer used for manufacturing the shell part of the core-shell hyperbranched polymer)
Next, monomers used for the production of the shell portion of the core-shell hyperbranched polymer will be described. The shell portion of the core-shell hyperbranched polymer constitutes the end of the polymer molecule. Examples of the monomer used for producing the shell part of the core-shell hyperbranched polymer include, for example, a monomer that gives a repeating unit represented by the following formula (I), a monomer that gives a repeating unit represented by the formula (II), and these Examples include monomers selected from the group consisting of mixtures.

  The repeating unit represented by the following formula (I) or the following formula (II) is, for example, an acid-decomposable group that is decomposed 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. Is included. The repeating unit represented by the following formula (I) or the following formula (II) preferably contains an acid-decomposable group that decomposes by the action of a photoacid generator that generates an acid by light energy. As the acid-decomposable group, those capable of decomposing into a hydrophilic group are preferable.

R ¹ in the above formula (I) and R ⁴ in the above formula (II) represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Among these, as R ¹ in the above formula (I) and R ⁴ in the above formula (II), a hydrogen atom and a methyl group are preferable. The R ⁴ in R1 and the formula in the formula (I) (II), more preferably a hydrogen atom.

R ² in the above formula (I) represents a hydrogen atom, an alkyl group, or an aryl group. The alkyl group for R ² in the above formula (I) preferably has, for example, 1 to 30 carbon atoms. The more preferable carbon number of the alkyl group in R < ² > in the said formula (I) is 1-20. The more preferable carbon number of the alkyl group in R < ² > in the said formula (I) 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 (I) 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. .

The aryl group in R ² in the formula (I), for example, is preferably 6 to 30 carbon atoms. The more preferable carbon number of the aryl group in R ² in the above formula (I) is 6-20. The more preferable carbon number of the aryl group in R ² in the above formula (I) is 6-10. Specifically, examples of the aryl group for R ² in the above formula (I) 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 (I), one of the most preferred groups is a hydrogen atom.

R ³ in the above formula (I) and R ⁵ in the above formula (II) 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 (I) and R ⁵ in the above formula (II) preferably has 1 to 40 carbon atoms. The carbon number of the alkyl group in R ³ in the above formula (I) and R ⁵ in the above formula (II) is preferably 1-30. The still more preferable carbon number of the alkyl group in R < ³ > in the said Formula (I) and R < ⁵ > in the said Formula (II) is 1-20. The alkyl group in R ³ in the above formula (I) and R ⁵ in the above formula (II) has a linear, branched or cyclic structure.

The carbon number of each alkyl group in R ³ in the above formula (I) and R ⁵ in the above formula (II) is preferably 1 to 6, and more preferably 1 to 4. The carbon number of the alkyl group of the oxoalkyl group in R ³ in the above formula (I) and R ⁵ in the above formula (II) 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. The number of carbon atoms of the alkyl group in R ⁶ of the group represented by the following formula (i) is preferably 1-10. The more preferable carbon number of the alkyl group in R < ⁶ > of the 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. The number of carbon atoms of the alkyl group in R ⁷ and R ⁸ in the above formula (i) is preferably 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 formula (i), among the above-mentioned groups, an ethoxyethyl group, a butoxyethyl group, an ethoxypropyl group, and a tetrahydropyranyl group are particularly preferable.

R ³ in the above formula (I) and R ⁵ in the above formula (II) are linear or branched having 1 to 40 carbon atoms, preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms. A cyclic or cyclic alkyl group is preferred. R ³ in the above formula (I) and R ⁵ in the above formula (II) are more preferably a branched alkyl group having 1 to 20 carbon atoms.

In R ³ in the above formula (I) and R ⁵ in the above formula (II), 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 (I) and R ⁵ in the above formula (II), the trialkylsilyl group has a carbon number 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.

  As the monomer that gives the repeating unit represented by the above formula (I), 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, vinylbenzoic acid 2-d Lu-2-adamantyl, 3-hydroxy-1-adamantyl vinyl benzoate, tetrahydrofuranyl vinyl benzoate, tetrahydropyranyl vinyl benzoate, 1-methoxyethyl vinyl benzoate, 1-ethoxyethyl vinyl benzoate, vinyl benzoic 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- Me Xyl-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-butyl Tyrolactone, 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, vinylbenzoic acid 1- Methylcyclohexyl, adamantyl vinylbenzoate, 2- (2-methyl) adamantyl vinylbenzoate, chloroethyl vinylbenzoate, 2-hydroxyethyl vinylbenzoate, 2,2-dimethylhydroxypropyl vinylbenzoate, 5-hydroxyvinylbenzoate Examples include pentyl, trimethylolpropane vinyl benzoate, glycidyl vinyl benzoate, benzyl vinyl benzoate, phenyl vinyl benzoate, and naphthyl vinyl benzoate. Of these, a polymer of 4-vinylbenzoic acid and tert-butyl 4-vinylbenzoate is preferable.

  Examples of the monomer that gives the repeating unit represented by the above formula (II) 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-adamantyl, Tetrahydrofuranyl acrylate, tetrahydropyranyl acrylate, 1-methoxyethyl acrylate, 1-ethoxyethyl acrylate, 1-n-propoxyethyl acrylate, 1-isopropoxyethyl acrylate, n-butoxyethyl acrylate, acrylic 1-isobutoxyethyl acid, 1-sec-butoxyethyl acrylate, 1-tert-butoxyethyl acrylate, 1-tert-amyloxyethyl acrylate, 1-ethoxy-n-propyl acrylate, 1-cyclohexyl acrylate Siloxyethyl, methoxypropyl acrylate, ethoxypropyl acrylate, 1-methoxy-1-methyl-ethyl acrylate, 1-ethoxy-1-methyl-ethyl acrylate, trimethylsilyl acrylate, triethylsilyl acrylate, acrylic acid Dimethyl-tert-butylsilyl, 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- (Acroyl) oxy-δ-valerolactone, δ- (Acroyl) oxy-δ- Valerolactone, α-methyl-α- (4-vinylbenzoyl) oxy-δ-valerolactone, β-methyl-β- (acroyl) oxy-δ-valerolactone, γ-methyl-γ- (acroyl) oxy-δ -Valerolactone, δ-methyl-δ- (acryloyl) oxy-δ-valerolactone, α-ethyl-α- (acryloyl) oxy-δ-valerolactone, β-ethyl-β- (acryloyl) oxy-δ-valero Lactone, γ-ethyl-γ- (acryloyl) oxy-δ-valerolactone, δ-ethyl-δ- (acryloyl) oxy-δ-valerolactone, 1-methylcyclohexyl acrylate, adamantyl acrylate, 2- (acrylate) 2-methyl) adamantyl, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2,2-dimethylhydroxyacrylate Propyl, 5-hydroxypentyl acrylate, trimethylolpropane acrylate, glycidyl acrylate, benzyl acrylate, phenyl acrylate, naphthyl acrylate, methacrylic acid, tert-butyl methacrylate, 2-methylbutyl methacrylate, 2-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 1- Ethyl-1-cyclopentyl, 1-methyl-1-cyclohexyl methacrylate, 1-ethyl-1-cyclohexyl methacrylate, 1-methylnorbornyl methacrylate, 1-ethylnorbornyl methacrylate 2-methyl-2-adamantyl methacrylate, 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, tetrahydrofuranyl methacrylate, tetrahydropyranyl methacrylate, 1-methoxyethyl methacrylate, methacrylic acid 1-ethoxyethyl acid, 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, ethoxy methacrylate Propyl, 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- (methacryloyl) oxy-γ-butyrolactone, α-ethyl-α- (methacryloyl) oxy-γ-butyrolactone, β-ethyl-β- (methacryloyl) 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- (methacloyl) oxy-δ-valerolactone, γ-methyl-γ- (methacloyl) oxy -Δ-valerolactone, δ-methyl-δ- (methacryloyl) oxy-δ-valerolactone, α-ethyl-α- (methacryloyl) oxy-δ-valerolactone, β-ethyl-β- (methacryloyl) oxy-δ Valerolactone, γ-ethyl-γ- (methacloyl) oxy-δ-valerolactone, δ-ethyl-δ- (methacloyl) oxy -Δ-valerolactone, 1-methylcyclohexyl methacrylate, adamantyl methacrylate, 2- (2methyl) adamantyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2,2-dimethylhydroxypropyl methacrylate, methacrylic acid Examples include 5-hydroxypentyl, trimethylolpropane methacrylate, glycidyl methacrylate, benzyl methacrylate, phenyl methacrylate, naphthyl methacrylate, and the like. Among these, a polymer of acrylic acid and tert-butyl acrylate is preferable.

  In addition, as a monomer corresponding to the shell portion, a polymer of at least one of 4-vinylbenzoic acid or acrylic acid and at least one of tert-butyl 4-vinylbenzoate or tert-butyl acrylate is also preferable. The monomer corresponding to the shell portion may be a monomer other than the monomer that gives the repeating unit represented by the above formula (I) and the above formula (II) as long as it has a structure having a radical polymerizable unsaturated bond. .

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

  Specific examples of the styrenes listed as polymerization monomers that can be used as a monomer for forming 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 Len, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, And vinyl naphthalene.

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

  Specific examples of vinyl ethers listed as polymerization monomers that can be used as the monomer for forming the shell portion include hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, Chlorethyl 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 Ether, vinyl chlorophenyl ether, vinyl 2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthranyl ether, and the like. Specific examples of vinyl esters listed as polymerization monomers that can be used as a monomer for forming 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. It is done.

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

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

  Among the polymerization monomers that can be used as the monomer for forming the shell portion, styrenes and crotonic acid esters are preferable. Among the polymerization monomers that can be used as the monomer for forming the shell portion, styrene, benzylstyrene, chlorostyrene, vinylnaphthalene, butyl crotonate, hexyl crotonate, and maleic anhydride are preferable.

  The shell part of the core-shell hyperbranched polymer is obtained by reacting the core part of the hyperbranched polymer synthesized as described above with the monomer containing an acid-decomposable group, thereby synthesizing the hyperbranch synthesized as described above. It can be introduced at the end of the polymer. Examples of the monomer containing an acid-decomposable group in the core portion of the hyperbranched polymer include monomers that give at least a repeating unit represented by the above formula (I) or the above formula (II). Thereby, at least an acid-decomposable group that gives a repeating unit represented by the above formula (I) or the above formula (II) can be introduced into the shell portion of the core-shell hyperbranched polymer.

  In the core-shell hyperbranched polymer of the present invention, the monomer that gives a repeating unit represented by at least one of the above formula (I) or the above formula (II) is 10 to 90 mol% with respect to the core-shell hyperbranched polymer. It is preferable that it is included in the range. A more preferable range is 20 to 90 mol%, and an even more preferable range is 30 to 90 mol%. In particular, it is preferable that the repeating unit represented by at least one of the above formula (I) or the above formula (II) in the shell part is contained in the range of 50 to 100 mol% with respect to the core-shell hyperbranched polymer. More preferably, it is contained in the range of 80 to 100 mol%.

  When the repeating unit represented by at least one of the above formula (I) or the above formula (II) in the shell is within the above-mentioned range with respect to the core-shell hyperbranched polymer, the core-shell hyperbranched polymer is used. In the lithography development step using the resist composition, the exposed portion is preferably dissolved and removed in the alkaline solution efficiently.

  When the shell part of the core-shell hyperbranched polymer is a polymer of a monomer that gives a repeating unit represented by at least one of the above formula (I) or the above formula (II) and another monomer, the shell part is formed. The amount of the monomer that gives the repeating unit represented by at least one of the above formula (I) or the above formula (II) in all monomers is preferably 30 to 90 mol%, and 50 to 70 mol% at the time of charging. It is more preferable that Within such a range, functions such as etching resistance, wettability, and increase in glass transition temperature are imparted without hindering efficient alkali solubility in the exposed area. The amount of the repeating unit represented by at least one of the above formula (I) or the above formula (II) in the shell portion of the core-shell hyperbranched polymer and the other repeating units depends on the purpose when the shell portion is introduced. The molar ratio can be adjusted by adjusting the charged amount ratio.

  The weight average molecular weight (Mw) of the core-shell hyperbranched polymer of the present invention is preferably 500 to 150,000, more preferably 500 to 100,000, still more preferably 1,000 to 50,000, and most preferably 1. 30,000 to 30,000. When the weight average molecular weight (Mw) of the core-shell hyperbranched polymer is in such a range, the resist containing the core-shell hyperbranched polymer has good film formability, and has a processing pattern formed in the lithography process. The shape can be maintained because of its strength. It also has excellent dry etching resistance and good surface roughness.

  The core-shell hyperbranched polymer in which the core part of the present invention has a structure derived from hyperbranched polyol has a significantly high alkali dissolution rate contrast before and after exposure, high sensitivity and high resolution. It can be made very effective as a resist material for ultra LSI with a thickness of 100 nm or less. In addition, the increased solubility after exposure can also improve the T-top pattern that is affected by environmental influences in the case of fine patterns of 100 nm or less. Furthermore, since the solubility after exposure has increased, a small amount of remaining film, which is a concern when producing fine patterns of 100 nm or less, can be improved.

  Here, the weight average molecular weight (Mw) of the core-shell hyperbranched polymer of the present invention is obtained by preparing a 0.05 mass% tetrahydrofuran solution and performing GPC measurement at a temperature of 40 ° C., and using tetrahydrofuran as the mobile solvent. Polystyrene was used as a standard substance.

Sensitivity is exposed, for example, by using ultraviolet silicon wafer light (EUV) to irradiate light of energy 0 to 200 mJ / cm ² to a predetermined size portion of a sample thin film formed to a predetermined thickness on a silicon wafer. After the heat treatment, the film is immersed in an alkaline aqueous solution, developed, washed with water, and the film thickness after drying is measured with a thin film measuring apparatus. The minimum irradiation dose (mJ / cm ² ) at which the film thickness reduction in the exposed area becomes 100%. Can be obtained by using the sensitivity.

  The surface roughness of the exposed surface is, for example, the method described in Masao Nagase, Waseda University Review Thesis 2475, “Study on Nanostructure Measurement by Atomic Force Microscope and its Application to Devices and Processes”, pp99-107 (1996). Can be measured according to. Specifically, the electron beam, ultraviolet ray, or EUV light can be used for the surface of the electron beam, ultraviolet ray, or 30% of the EUV exposure amount that showed solubility in the alkaline aqueous solution. For an evaluation sample prepared in the same manner as described for the solubility in an alkaline aqueous solution, measured using an atomic force microscope according to the ten-point average roughness of JIS B0601-1994, which is an index of surface roughness. it can.

  The etching rate can be measured, for example, by performing dry etching using a dry etching apparatus (TCP9400 Type manufactured by LAM Research) and obtaining a film thickness difference before and after the dry etching.

(Resist composition)
The resist composition of the present invention contains at least the core-shell hyperbranched polymer of the present invention, a photoacid generator, and if necessary, an acid diffusion inhibitor (acid scavenger), a surfactant, other components, And solvents. 1-40 mass% is preferable with respect to the whole quantity of a resist composition, and, as for the compounding quantity of the said core-shell type hyperbranched polymer of this invention, 1-20 mass% is more preferable.

  The photoacid generator is not particularly limited as long as it generates an acid upon irradiation with ultraviolet rays, X-rays, electron beams, and the like, and can be appropriately selected from known ones according to the purpose. Examples 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 include diaryl iodonium salts, triaryl selenonium salts, and triaryl sulfonium salts. Examples of the diaryliodonium salt include diphenyliodonium trifluoromethanesulfonate, bis-4-tert-butylphenyliodonium nonafluoromethanesulfonate, bis4-tert-butylphenyliodonium camphorsulfonate, 4-methoxyphenyliodonium hexafluoroantimonate. 4-methoxyphenyliodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, bis (4-tert-butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium hexafluoro Antimonate, bis (4-tert-butylphenyl) iodonium trifluoromethanes Honeto, bis (4-tert-butylphenyl -) Yodoniumuji (perfluoromethyl sulfone) imidate, bis (4-tert- butylphenyl) iodonium - tri (perfluoromethyl sulfone) methanide and the like. Examples of the triarylselenonium salt include triphenylselenonium hexafluorophosphonium salt, triphenylselenonium borofluoride, triphenylselenonium hexafluoroantimonate salt, and the like.

  Examples of the triarylsulfonium salt include triphenylsulfonium hexafluorophosphonium salt, triphenylsulfonium hexafluoroantimonate salt, diphenyl-4-thiophenoxyphenylsulfonium hexafluoroantimonate salt, diphenyl-4-thiophenoxyphenylsulfonium penta Fluorohydroxyantimonate salts and the like.

  Examples of the sulfonium salt include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, 4-methoxyphenyl. Diphenylsulfonium hexafluoroantimonate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenylsulfonium trifluoromethanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyldiphenylsulfonium trifluoromethane Sulfonate, 4-phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate, 1- (2-naphthoylmethyl) thiolanium hexafluoroantimonate, 1- (2-naphthoylmethyl) Thioronium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium hexafluoroantimonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate, triphenylsulfonium-di (perfluoromethylsulfone) imidate, triphenylsulfonium- Di (perfluorobutylsulfone) imidate, triphenylsulfonium-cyclo (perfluoropropanedisulfo ) Imidate, triphenylsulfonium - tri (perfluoromethyl sulfone) methanide, and the like.

  Examples of the halogen-containing triazine compound include 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4,6-tris (trichloromethyl) -1,3,5- Triazine, 2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-chlorophenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -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-triazine, 2- (4-methoxy) Styryl) -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-butoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-pentyloxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, and the like.

  Examples of the sulfone compound include diphenyldisulfone, di-p-tolyldisulfone, bis (phenylsulfonyl) diazomethane, bis (4-chlorophenylsulfonyl) diazomethane, bis (p-tolylsulfonyl) diazomethane, and bis (4-tert-butyl). Phenylsulfonyl) diazomethane, bis (2,4-xylylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, (benzoyl) (phenylsulfonyl) diazomethane, phenylsulfonylacetophenone, and the like.

  Examples of the aromatic sulfonate compound include α-benzoylbenzyl p-toluenesulfonate (common name: benzoin tosylate), β-benzoyl-β-hydroxyphenethyl p-toluenesulfonate (common name: α-methylol benzoin tosylate), 1,2 , 3-Benzenetriyltrismethanesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, 2-nitrobenzyl p-toluenesulfonate, 4-nitrobenzyl p-toluenesulfonate, pyrogallol trimesylate and the like.

  Examples of the sulfonate compound of N-hydroxyimide 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- (trifluoro Methylsulfonyloxy) -5-norbornene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthalimide, N- (10-camphorsulfur Niruokishi) naphthalimide, and the like.

  Examples of the photoacid generator include sulfonium salts, particularly triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoromethanesulfonate, triphenylsulfonium-di (perfluoromethylsulfone) imidate, triphenylsulfonium-di (perfluoro). Butylsulfone) imidate, triphenylsulfonium-cyclo (perfluoropropanedisulfone) imidate, triphenylsulfonium-tri (perfluoromethylsulfone) methanide; sulfone compounds, especially bis (4-tert-butylphenylsulfonyl) diazomethane, bis (cyclohexyl) Sulfonyl) diazomethane is preferred.

  The photoacid generators can be used alone or in admixture of two or more. There is no restriction | limiting in particular as a compounding quantity of the said photo-acid generator, Although it can select suitably according to the objective, 0.1-30 mass parts is with respect to 100 mass parts of the said core-shell type hyperbranched polymer of this invention. Preferably, 0.1-20 mass parts is more preferable.

  Further, the acid diffusion inhibitor is not particularly limited as long as it is a component having an action of controlling an undesired chemical reaction in a non-exposed region by controlling a diffusion phenomenon in the resist film of an acid generated from an acid generator by exposure. And can be appropriately selected from known ones according to the purpose. For example, a nitrogen-containing compound having one nitrogen atom in the same molecule, a compound having two nitrogen atoms in the same molecule, 3 nitrogen atoms Examples thereof include polyamino compounds and polymers having at least one compound, amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds.

  Examples of the nitrogen-containing compound having one nitrogen atom in the same molecule include mono (cyclo) alkylamine, di (cyclo) alkylamine, tri (cyclo) alkylamine, and aromatic amine. Examples of the mono (cyclo) alkylamine include 2-cyclohexyl-2-pyrrolidinone, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and cyclohexylamine. . Examples of the di (cyclo) alkylamine include di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, and di-n-. Nonylamine, di-n-decylamine, cyclohexylmethylamine, and the like.

  Examples of the tri (cyclo) alkylamine include triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri- Examples thereof include n-octylamine, tri-n-nonylamine, tri-n-decylamine, cyclohexyldimethylamine, methyldicyclohexylamine, tricyclohexylamine and the like. Examples of the aromatic amine include 2-benzylpyridine, aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, And triphenylamine and naphthylamine.

  Examples of the nitrogen-containing compound having two nitrogen atoms in the same molecule include ethylenediamine, N, N, N′N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 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, 1,3-bis [1- (4-amino Phenyl) -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 include polyethyleneimine, polyallylamine, N- (2-dimethylaminoethyl) acrylamide polymer, and the like.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-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-butoxycarbonylhexamethyl Diamine, N, N′-di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxy Carbonyl-1,9-diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N ′ -Di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole , Formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylamide Toamido, N, N- dimethylacetamide, propionamide, benzamide, pyrrolidone, N- methylpyrrolidone, and the like.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butyl. And thiourea.

  Examples of the nitrogen-containing heterocyclic compound include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, pyridine, 2-methylpyridine, 4-methylpyridine, 2- Ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, Piperazine, 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpi Rajin, 1,4-diazabicyclo [2.2.2] octane, and the like.

  The acid diffusion inhibitors can be used alone or in admixture of two or more. There is no restriction | limiting in particular as a compounding quantity of the said acid diffusion inhibitor, Although it can select suitably according to the objective, 0.1-1000 mass parts is preferable with respect to 100 mass parts of said photoacid generators, and 0.0. 5-100 mass parts is more preferable.

  Further, the surfactant is not particularly limited as long as it is a component that exhibits an effect of improving coatability, striation, developability, etc., and can be appropriately selected from known ones according to the purpose. , Polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, sorbitan fatty acid ester, nonionic surfactant of polyoxyethylene sorbitan fatty acid ester, fluorine-based surfactant, silicon-based surfactant, and the like.

  Examples of the polyoxyethylene alkyl ether include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether having an average addition mole number of polyoxyethylene of 1 to 50, and the like. Is mentioned. Examples of the polyoxyethylene alkyl allyl ether include polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether having an average addition mole number of polyoxyethylene of 1 to 50.

  Examples of the sorbitan fatty acid ester include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, and the like.

  Examples of the nonionic surfactant of the polyoxyethylene sorbitan fatty acid ester include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate having an average addition mole number of polyoxyethylene of 1 to 50, Examples include polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, and the like.

  Examples of the fluorine-based surfactant include F-top EF301, EF303, and EF352 (manufactured by Shin-Akita Kasei Co., Ltd.), MegaFuck F171, F173, F176, F189, and R08 (manufactured by Dainippon Ink & Chemicals, Inc.). , FLORAD FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.), and the like.

  Examples of the silicon surfactant include organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The surfactants can be used alone or in admixture of two or more. The amount of the surfactant to be blended is not particularly limited and may be appropriately selected depending on the intended purpose, but is 0.0001 to 5 parts by mass with respect to 100 parts by mass of the core-shell hyperbranched polymer of the present invention. Preferably, 0.0002 to 2 parts by mass is more preferable.

  Examples of the other components include 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, an antihalation agent, and the like. Is mentioned.

  As the 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. As long as it has, there is no particular limitation, and examples thereof include acetophenones, benzophenones, naphthalenes, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers can be used alone or in admixture of two or more.

  The dissolution control agent is not particularly limited as long as it can more appropriately control the dissolution contrast and dissolution rate when used as a resist, and examples thereof include polyketones and polyspiroketals. These dissolution control agents can be used alone or in admixture of two or more.

  The additive having an acid-dissociable group is not particularly limited as long as it further improves dry etching resistance, pattern shape, adhesion to the substrate, and the like. For example, 1-adamantane carboxylate t-butyl, -T-butoxycarbonylmethyl adamantanecarboxylate, di-t-butyl 1,3-adamantane dicarboxylate, t-butyl 1-adamantane acetate, t-butoxycarbonylmethyl 1-adamantane acetate, di- 1,3-adamantane diacetate t-butyl, deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-ethoxyethyl, deoxycholic acid 2-cyclohexyloxyethyl, deoxycholic acid 3-oxocyclohexyl, deoxycholic acid tetrahydropyrani And deoxycholate Lonolactone ester, t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, tetrahydropyranyl lithocholic acid, mevalono lithocholic acid Lactone esters, and the like. These dissolution control agents can be used alone or in admixture of two or more.

  The alkali-soluble resin is not particularly limited as long as it improves the alkali-solubility of the resist composition of the present invention. For example, poly (4-hydroxystyrene), partially hydrogenated poly (4-hydroxystyrene), poly (3-hydroxystyrene), poly (3-hydroxystyrene), 4-hydroxystyrene / 3-hydroxystyrene copolymer, 4-hydroxystyrene / styrene copolymer, novolac resin, polyvinyl alcohol, polyacrylic acid and the like. Mw is usually from 1,000 to 1,000,000, preferably from 2,000 to 100,000. These alkali-soluble resins can be used alone or in admixture of two or more.

  The dye or the pigment can visualize the latent image in the exposed area and can reduce the influence of halation during exposure. In addition, the adhesion aid can improve the adhesion to the substrate. The solvent is not particularly limited as long as it can dissolve the components and the like, and can be appropriately selected from those that can be safely used in resist compositions. For example, ketone, cyclic ketone, propylene glycol monoalkyl Examples include ether acetate, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, and other solvents.

  Examples of the ketone include methyl isobutyl ketone, methyl ethyl ketone, 2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3 , 3-dimethyl-2-butanone, 2-heptanone, 2-octanone, and the like. Examples of the cyclic ketone include cyclohexanone, cyclopentanone, 3-methylcyclopentanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, and isophorone.

  Examples of the propylene glycol monoalkyl ether acetate 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 acetate, and the like.

  Examples of the alkyl 2-hydroxypropionate include methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, n-propyl 2-hydroxypropionate, i-propyl 2-hydroxypropionate, and n-hydroxypropionate n. -Butyl, i-butyl 2-hydroxypropionate, sec-butyl 2-hydroxypropionate, t-butyl 2-hydroxypropionate, and the like. Examples of the alkyl 3-alkoxypropionate include methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, and the like.

  Examples of the other solvent include n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclohexanol, 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, methyl 2-hydroxy-3-methylbutyrate, 3 -Methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate , Methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glyco Rumonomethyl ether, diethylene glycol monoethyl ether, γ-butyrolactone, toluene, xylene, caproic acid, caprylic acid, octane, decane, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, malein Examples include diethyl acid, ethylene carbonate, and propylene carbonate. These solvents can be used alone or in admixture of two or more.

  The resist composition of the present invention can be subjected to patterning by developing after being exposed on the pattern. The resist composition of the present invention can form fine patterns for manufacturing semiconductor devices for electron beams, deep ultraviolet (DUV), and extreme ultraviolet (EUV) light sources that require surface smoothness on the nano order. It can be used suitably. The resist composition of the present invention can be dissolved in an alkali developer by exposure and heating, washed with water, and the like, so that there is no undissolved residue on the exposed surface and a substantially vertical edge can be obtained. An organic or inorganic antireflection film can be provided between the substrate and the coating layer of the resist composition.

  Examples of the above-described embodiment according to the present invention will be described below. Note that the scope of the present invention is not limited to the examples described below.

<Hyperbranch polyol A>
As the hyperbranched polyether with Mn = 2000, Hyperbranched Polymerics molecular weight 2000 (catalog No. PG-2) manufactured by Hyper Polymers was used.
More purchased and used.

<Hyperbranch polyol B>
As the hyperbranched polyether with Mn = 6000, Hyperbranched Polymerics molecular weight 6000 (catalog No. PG-6) manufactured by Hyper Polymers was used.

<Hyperbranch polyol C>
Gabriel Rokkicki, Pawel Rakoczy, Pawel Parzuchowski and Marcin Sobiecki, Green Chem. The following synthesis was performed with reference to the synthesis method described in 2005, 7, 529-539.

(Synthesis of glycerol carbonate)
A 100 mL reaction vessel was charged with 40 g of glycerol, 117.5 g of dimethyl carbonate, and 1.8 g of potassium carbonate, and reacted at the boiling point for 3 hours. After completion of the reaction, it was removed under reduced pressure. Then, it passed through cation exchange resin Amberlite IR-120, and obtained the target object.

(Synthesis of hyperbranched polyol C)
In a 300 mL reaction vessel, methanol was added, potassium methoxide was added to 25%, nitrogen bubbling was performed, and the reaction was performed in a nitrogen atmosphere. Thereto, 5 g of 1,1,1-tris (hydroxymethyl) propane was added, and sales were expanded for 1 hour. Next, glycerol carbonate was slowly added dropwise, 45 g was added, and reacted at 170 ° C. for 12 hours. After completion of the reaction, the product was obtained through a cation exchange resin. The target product was obtained by Green Chem. By ¹ H-NMR and ¹³ C-NMR. It was confirmed that the peak was described in 2005, 7, 529-539.

<Hyperbranch polyol D>
Boltorn 20 manufactured by Perstorp Japan was used.
<Hyperbranch polyol E>
Boltorn 30 manufactured by Perstorp Japan was used.
<Hyperbranch polyol F>
Boltorn 40 manufactured by Perstorp Japan was used.
<Hyperbranch polyol G>
A highly branched polyesteramide (HYBRANE) manufactured by DSM was used.

Example 1
Hyper branch (1)
In a 100 mL eggplant-shaped flask, under a nitrogen atmosphere, 1.1 g of hyperbranched polyol A and 5 mL of diethoxyethane were mixed, and 1.8 g of diisopropylethylamine / diethoxyethane solution (10 mL) was added. A 1 g / diethoxyethane solution (10 mL) was added dropwise. After reacting at 125 ° C. for 35 hours, the resulting mixture was transferred to a separatory funnel containing ethyl acetate / 0.5N hydrochloric acid, and the organic phase was extracted and extracted again with 0.5N hydrochloric acid. Next, the organic phase was washed in the order of saturated aqueous sodium hydrogen carbonate solution, water and saturated brine, and dehydrated by adding an appropriate amount of anhydrous sodium sulfate. After filtering the desiccant, the solvent was distilled off with an evaporator, followed by vacuum drying to obtain the desired product.

  Next, in a 300 mL reaction vessel, 1.0 g of hyperbranch (1), 1.4 g of acrylic acid, 2.56 g of acrylic acid tertbutyl ester, 200 mL of N-methyl-2-pyrrolidone, initiator 2,2′- 1.4 g of azobis [N- (2-propenyl) -2-methylpropionamide] VF096 (manufactured by Wako Pure Chemical Industries, Ltd.) was put in a nitrogen atmosphere. After mixing, the mixture was reacted at 100 ° C. for 2 hours. After completion of the reaction, methanol was added and the precipitate was dried to obtain <Polymer 1> as the target product.

-Preparation of resist composition-
Propylene glycol monomethyl ether acetate (PEGMEA) solution containing 4.0% by mass of <Polymer 1> and 0.16% by mass of triphenylsulfonium trifluoromethanesulfonate as a photoacid generator was prepared, and a filter having a pore size of 0.45 μm To prepare a resist composition. The obtained resist composition was spin-coated on a silicon wafer, and the solvent was evaporated by a heat treatment at 90 ° C. for 1 minute to prepare a thin film having a thickness of 100 nm.

-UV sensitivity measurement-
As a light source, a discharge tube type ultraviolet irradiation device (manufactured by Ato Co., Ltd., DF-245 type DonaFix) was used. To the sample thin film having a thickness of about 100nm was deposited on a silicon wafer, a rectangular portion of the vertical 10 mm × horizontal 3 mm, an ultraviolet ray having a wavelength of 245 nm, by varying the amount of energy from 0 mJ / cm ² to 50 mJ / cm ² It was exposed by irradiation. After heat treatment at 100 ° C. for 4 minutes, the film was immersed in a 2.4% by weight aqueous solution of tetramethylammonium hydroxide (TMAH) at 25 ° C. for 2 minutes for development. The film thickness after washing and drying was measured with a thin film measuring apparatus F20 manufactured by Filmetics Co., Ltd., and the minimum energy amount when the film thickness after development became zero was defined as sensitivity. The results are shown in Table 1.

-Measurement of surface roughness-
For the surface roughness of the exposed surface, refer to the method described in Masao Nagase, Waseda University Examination Dissertation No. 2475, “Study on Nanostructure Measurement by Atomic Force Microscope and its Application to Devices and Processes”, pp99-107 (1996). The surface was exposed to 30% of the exposure amount that showed solubility in the alkaline aqueous solution using the extreme ultraviolet light (EUV). EUV irradiation is performed on a rectangular thin film having a length of 10 mm and a width of 3 mm on a sample thin film having a thickness of about 500 nm formed on a silicon wafer. After heat treatment at 100 ° C. for 4 minutes, tetramethylammonium hydroxide ( TMAH) A surface that was immersed in a 2.4 mass% aqueous solution at 25 ° C. for 2 minutes, washed with water, and dried was used as an evaluation sample.

  The obtained evaluation sample was measured using an atomic force microscope (SPM-9500J3, manufactured by Shimadzu Corporation) according to the ten-point average roughness of JIS B0601-1994, which is an index of surface roughness. The results are shown in Table 1.

(Example 2)
Using hyperbranched polyol B, hyperbranch (2) was synthesized in the same manner as in Example 1. <Polymer 2> was synthesized in the same manner as in Example 1 using hyperbranch (2).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 2> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

(Example 3)
Using hyperbranched polyol D, hyperbranch (3) was synthesized in the same manner as in Example 1. <Polymer 3> was synthesized in the same manner as in Example 1 using hyperbranch (3).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 3> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

Example 4
Using hyperbranched polyol E, hyperbranch (4) was synthesized in the same manner as in Example 1. <Polymer 4> was synthesized in the same manner as in Example 1 using hyperbranch (4).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 4> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

(Example 5)
Using hyperbranched polyol G, hyperbranch (5) was synthesized in the same manner as in Example 1. <Polymer 5> was synthesized in the same manner as in Example 1 using hyperbranch (5).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 5> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

(Example 6)
1.0 g of hyperbranched polyol A and 300 ml of dehydrated N-methyl-2-pyrrolidone were charged and dissolved by heating to 70 ° C. with stirring. After cooling with ice water, 42.3 g of 2-bromoisobutyryl bromide was added dropwise thereto, the ice bath was removed, and the mixture was stirred at room temperature for 20 hours. The reaction system is cooled again in an ice bath, methyl-tert-butyl ether cooled in advance in an ice bath is added, washed with ion-exchanged water cooled in an ice bath, and the washing is extracted with methyl-tert-butyl ether. The layers were combined, washed with a 5% by weight aqueous sodium bicarbonate solution, further washed with ion-exchanged water, and the solvent was removed by running under reduced pressure. This solution was crystallized with ion-exchanged water, recrystallized using methanol, and then dried under reduced pressure to obtain the desired product hyperbranch (6).

  Next, in a reaction vessel purged with nitrogen, 23.2 g of hyperbranch (6), 68.2 g of tertbutyl acrylate, 445 g of pyridine, copper bromide. 63 g and bipyridyl 8.3 g were added, and the mixture was reacted at 110 ° C. for 5 hours while stirring at 300 rpm. Subsequently, the reaction solution was cooled to room temperature with stirring, and then the copper catalyst was removed. Then, reprecipitation was performed with a methanol / water mixed solvent to obtain a product. After drying, 90 g of 1,4-dioxane was added to and dissolved in 10 g of the obtained product, 10 g of 50% by mass sulfuric acid aqueous solution was placed in a reaction vessel, and reacted at 100 ° C. for 70 minutes. After completion of the reaction, the polymer is precipitated by slowly pouring into 900 g of ultrapure water having a volume 10 times that of 1,4-dioxane with stirring, and then filtered and dried to obtain the target product <Polymer 6> Got.

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 6> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

(Example 7)
Using hyperbranched polyol C, hyperbranch (7) was synthesized in the same manner as in Example 6. <Polymer 7> was synthesized in the same manner as in Example 1 using hyperbranch (7).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 7> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

(Example 8)
Using hyperbranched polyol D, hyperbranch (8) was synthesized in the same manner as in Example 6. <Polymer 8> was synthesized in the same manner as in Example 1 using hyperbranch (8).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 8> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

Example 9
Using hyperbranched polyol F, hyperbranch (9) was synthesized in the same manner as in Example 6. <Polymer 9> was synthesized in the same manner as in Example 1 using hyperbranch (9).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 9> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

(Example 10)
Using hyperbranched polyol G, hyperbranch (10) was synthesized in the same manner as in Example 6. <Polymer 10> was synthesized in the same manner as in Example 1 using hyperbranch (10).

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 10> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

(Comparative Example 1)
-Synthesis of hyperbranched polymer core part A-
Krzysztof Matyjaszewski, Macromolecules 29, 1079 (1996) and Jean M. et al. J. et al. Frecht, J .; Poly. Sci. , 36, 955 (1998), and the following synthesis was performed with reference to the synthesis method.

  In a 1,000 mL four-necked reaction vessel equipped with a stirrer and a condenser tube, 49.2 g of 2.2′-bipyridyl and 15.6 g of copper (I) chloride were taken in an argon gas atmosphere, and 480 mL of chlorobenzene as a reaction solvent. Then, 96.6 g of chloromethylstyrene was added dropwise over 5 minutes, and the mixture was heated and stirred while keeping the internal temperature constant at 125 ° C. The reaction time including the dropping time was 40 minutes.

  After completion of the reaction, 300 mL of THF was added to the reaction mixture and stirred to dissolve the polymer product, and 400 g of alumina (100 g × 4 times) was suction filtered using a filter medium to separate copper chloride, and the filtrate was distilled off under reduced pressure. did. The filtrate obtained was reprecipitated by adding 700 mL of methanol to obtain a highly viscous brown crude polymer. To 80 g of the crude product polymer, 500 mL of a mixed solvent of THF: methanol = 2: 8 was added and stirred for 3 hours. After completion of the stirring, the polymer was precipitated, and thus the solvent was removed to obtain <Core A>.

-Synthesis of hyperbranched polymer-
Into a reaction vessel under an argon gas atmosphere containing 396 mg of copper (I) chloride, 1.24 g of 2,2′-bipyridyl and 2.43 g of <Core A> prepared above, 68.7 mL of monochlorobenzene, tert- 26.3 mL of butoxystyrene was injected with a syringe, and heated and stirred at 125 ° C. for 2 hours.

  After rapidly cooling the reaction mixture, 50 mL of THF was added and stirred, and the catalyst was removed by suction filtration using aluminum oxide as a filter medium. The obtained short yellow filtrate was distilled off under reduced pressure to obtain a crude product polymer. After dissolving the crude product in 10 mL of THF, 400 mL of methanol was added for reprecipitation. The reprecipitation solution was centrifuged to separate the solid content. The precipitate was washed with methanol to obtain a light yellow solid as a purified product.

-Deprotection process-
0.6 g of purified polymer was collected in a reaction vessel equipped with a reflux tube, 30 mL of dioxane and 0.6 mL of hydrochloric acid (30%) were added, and the mixture was stirred at 90 ° C. for 60 minutes. Next, the reaction crude product was poured into 300 mL of ultrapure water and reprecipitated to obtain a solid content. The solid was dissolved by adding 30 mL of dioxane and reprecipitated again. The solid content was recovered and dried to obtain <Polymer 12> of Comparative Example 2.

-Preparation of resist composition-
An evaluation sample was prepared after preparing a resist composition in the same manner as in Example 1 except that 4.0% by mass of <Polymer 12> was used.

-Evaluation-
In the same manner as in Example 1, the sensitivity of the ultraviolet ray (254 nm) exposure experiment was measured, and the surface roughness measurement was similarly performed. The results are shown in Table 1.

  As described above, the core-shell hyperbranched polymer, resist composition, method for manufacturing a semiconductor device, and semiconductor device according to the present invention include a resist composition used for manufacturing a semiconductor device, and a core-shell hyperbranched polymer contained in the resist composition. The present invention is useful for a semiconductor device manufactured using a resist composition and a method for manufacturing the semiconductor, and particularly for a resist composition used for manufacturing a semiconductor that requires ultrafine processing in the nanometer region, and the resist composition. It is suitable for the core-shell hyperbranched polymer, the semiconductor device manufactured using the resist composition, and the method for manufacturing the semiconductor.

Claims (7)

A core-shell hyperbranched polymer comprising a core part and a shell part provided at the end of the core part,
The core portion has a structure derived from hyperbranched polyol,
The core-shell hyperbranched polymer, wherein the shell portion has a portion where the solubility in an alkaline developer is increased by the action of an acid.   The core-shell hyperbranched polymer according to claim 1, wherein the hyperbranched polyol is a branched polyether polyol.   The core-shell hyperbranched polymer according to claim 1, wherein the hyperbranched polyol is a branched polyester polyol.   The core-shell hyperbranched polymer according to claim 1, wherein the hyperbranched polyol is a branched polyamide polyester polyol.   A resist composition comprising the core-shell hyperbranched polymer according to claim 1.   A resist pattern is formed on a semiconductor substrate using the resist composition according to claim 5.   A semiconductor device, wherein a resist pattern is formed on a semiconductor substrate by the resist composition according to claim 6.