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WO2023228691A1 - Composition de réserve de type positif - Google Patents

Composition de réserve de type positif Download PDF

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Publication number
WO2023228691A1
WO2023228691A1 PCT/JP2023/017090 JP2023017090W WO2023228691A1 WO 2023228691 A1 WO2023228691 A1 WO 2023228691A1 JP 2023017090 W JP2023017090 W JP 2023017090W WO 2023228691 A1 WO2023228691 A1 WO 2023228691A1
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WO
WIPO (PCT)
Prior art keywords
copolymer
group
monomer
formula
positive resist
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PCT/JP2023/017090
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English (en)
Japanese (ja)
Inventor
学 星野
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日本ゼオン株式会社
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Publication of WO2023228691A1 publication Critical patent/WO2023228691A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
    • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
    • C08F20/10—Esters
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/22—Esters containing halogen
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004—Photosensitive materials
    • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists

Definitions

  • the present invention relates to a positive resist composition.
  • ionizing radiation such as electron beams and short wavelength light such as ultraviolet rays (hereinafter, ionizing radiation and short wavelength light may be collectively referred to as "ionizing radiation, etc.")
  • ionizing radiation and short wavelength light may be collectively referred to as "ionizing radiation, etc.”
  • Polymers whose main chains are cleaved by irradiation to increase their solubility in developing solutions are used as main chain cleavage type positive resists.
  • Patent Document 1 describes ⁇ -chloroacrylate-1-phenyl-1-trifluoromethyl-2,2,2 as a main chain-cleaved positive resist that has excellent sensitivity to ionizing radiation and heat resistance.
  • a positive resist composition is disclosed that includes a positive resist made of a copolymer containing -trifluoroethyl units and ⁇ -methylstyrene units.
  • the resulting resist pattern must be clear, that is, the boundary between the part where the resist film remains (residual film) and the part where the resist film has dissolved is clear. Clarity is required. Specifically, from the perspective of making it possible to form a resist pattern with higher clarity, the resist does not dissolve in the developer unless the irradiation amount reaches a certain amount; It has the characteristic that the main chain is cut and dissolved in the developer, that is, the magnitude of the slope of the sensitivity curve that shows the relationship between the common logarithm of the dose of ionizing radiation, etc. and the residual film thickness of the resist after development. There is a need to increase the expressed ⁇ value.
  • an object of the present invention is to provide a positive resist composition that can form a resist pattern with excellent clarity.
  • the present inventor conducted extensive studies in order to achieve the above object.
  • the present inventor has determined that the EUV absorption coefficient of the copolymer containing two types of copolymers with a difference in surface free energy equal to or greater than a predetermined value, and the copolymer having a smaller surface free energy among these copolymers,
  • the present inventors have newly discovered that the above-mentioned problems can be solved by using a positive resist composition having a predetermined value or more, and have completed the present invention.
  • the present invention includes a copolymer A, a copolymer B, and a solvent, and The surface free energy of the coalesce A is smaller than the surface free energy of the copolymer B, and the difference between the surface free energy of the copolymer B and the surface free energy of the copolymer A is 3 mJ/m 2 or more. and a positive resist composition in which the copolymer A has an EUV absorption coefficient of 55000 cm -1 or more. With the above positive resist composition, a resist pattern with excellent clarity can be formed.
  • "surface free energy” and "EUV absorption coefficient” can be measured using the method described in the Example of this specification.
  • the EUV absorption coefficient of the copolymer B is preferably less than 55,000 cm ⁇ 1 . If the EUV absorption coefficient of copolymer B is less than the above upper limit, the clarity of the resist pattern can be improved.
  • the positive resist composition of [1] or [2] above preferably does not substantially contain a component having a weight average molecular weight of less than 1000.
  • the clarity of the resist pattern can be improved if it does not substantially contain components having a weight average molecular weight of less than 1000.
  • the proportion (presence or absence) of "a component having a weight average molecular weight of less than 1000" can be measured using the method described in Examples.
  • substantially not containing means not actively blending except in cases where it is unavoidably mixed. Specifically, it means that the content of components having a weight average molecular weight of less than 1000 in the positive resist composition is less than 0.05% by mass.
  • the copolymer A has the following formula (I): [In formula (I), L 1 is a divalent linking group having a fluorine atom, Ar 1 is an aromatic ring group which may have a substituent, and X 1 is a halogen atom, a cyano group, alkylsulfonyl group, alkoxy group, nitro group, acyl group, alkyl ester group, or halogenated alkyl group. ] It is preferable to have a monomer unit (I) represented by the following. If copolymer A has monomer unit (I), the clarity of the resist pattern can be improved. In addition, in this specification, “may have a substituent” means "unsubstituted or has a substituent.”
  • the proportion of the monomer unit (I) is greater than 0 mol% when the total monomer units in the copolymer A is 100 mol%. It is preferably 20 mol% or less.
  • the proportion of monomer units (I) is equal to or greater than the above lower limit, when the total monomer units in copolymer A is 100 mol %, sensitivity to ionizing radiation etc. can be improved.
  • the proportion of monomer unit (I) is equal to or less than the above upper limit when the total monomer units in copolymer A is 100 mol %, the clarity of the resist pattern can be improved.
  • resist residue the amount of residue that remains unintentionally in the space portion of the resist pattern.
  • the proportion of monomer units in a copolymer can be measured using a nuclear magnetic resonance (NMR) method such as 1 H-NMR.
  • the copolymer A has the following formula (II) different from the monomer unit (I): [In formula (II), R 1 is an organic group having 3 to 10 fluorine atoms, and X 2 is a halogen atom, cyano group, alkylsulfonyl group, alkoxy group, nitro group, acyl group, alkyl It is an ester group or a halogenated alkyl group. ] It is preferable to further have a monomer unit (II) represented by the following. If copolymer A further has monomer unit (II), the clarity of the resist pattern can be further improved.
  • the copolymer B has the following formula (IV): [In formula (IV), L 2 is a divalent linking group having a fluorine atom, Ar 2 is an aromatic ring group which may have a substituent, and X 3 is a halogen atom, a cyano group, alkylsulfonyl group, alkoxy group, nitro group, acyl group, alkyl ester group, or halogenated alkyl group.
  • Monomer unit (IV) represented by the following formula (V): [In formula (V), R 5 is an alkyl group, R 6 is a hydrogen atom, a fluorine atom, an unsubstituted alkyl group, or an alkyl group substituted with a fluorine atom, R 7 is a hydrogen atom, It is an unsubstituted alkyl group or an alkyl group substituted with a fluorine atom, r and s are integers from 0 to 5, and r+s 5. It is preferable to have a monomer unit (V) represented by the following. If copolymer B has monomer units (IV) and monomer units (V), the clarity of the resist pattern can be improved.
  • a positive resist composition that can form a resist pattern with excellent clarity can be provided.
  • the positive resist composition of the present invention can be used, for example, when forming a resist pattern in the manufacturing process of a printed circuit board such as a build-up board using ionizing radiation or the like.
  • the positive resist composition of the present invention contains a copolymer A, a copolymer B, and a solvent, which will be described in detail below, and optionally further contains known additives that can be blended into the positive resist composition. contains.
  • the surface free energy of copolymer A is smaller than the surface free energy of copolymer B, and the surface free energy of copolymer B is equal to the surface free energy of copolymer A.
  • the difference from the free energy is 3 mJ/m 2 or more, and the EUV absorption coefficient of copolymer A is 55000 cm -1 or more.
  • the surface free energy of copolymer A is smaller than the surface free energy of copolymer B, and the difference between the surface free energy of copolymer B and the surface free energy of copolymer A is 3 mJ/m2 or more.
  • copolymer A with low surface free energy can be favorably unevenly distributed on the surface side of the resist film, but the EUV absorption coefficient of copolymer A that is unevenly distributed on the surface side is If it is 55000 cm -1 or more, the sensitivity of the resist film to ionizing radiation etc. can become significantly high.
  • a resist pattern formed using the positive resist composition of the present invention can exhibit excellent clarity.
  • the positive resist composition described above can reduce the amount of resist residue.
  • the difference between the surface free energy of copolymer B and the surface free energy of copolymer A is , preferably 4 mJ/m 2 or more, more preferably 5.5 mJ/m 2 or more, even more preferably 6 mJ/m 2 or more, and still more preferably 6.5 mJ/m 2 or more. More preferably, it is 8 mJ/m 2 or more, even more preferably 9 mJ/m 2 or more, and particularly preferably 10 mJ/m 2 or more.
  • the difference between the surface free energy of copolymer B and the surface free energy of copolymer A is at least the above lower limit, the clarity of the resist pattern can be improved. Further, the reduction in the top of the resist pattern can be further suppressed. Furthermore, the amount of resist residue can be further reduced.
  • the difference between the surface free energy of copolymer B and the surface free energy of copolymer A is, for example, 14 mJ/m 2 or less, may be 13 mJ/m 2 or less, or may be 12 mJ/m 2 or less.
  • the positive resist composition of the present invention preferably does not substantially contain a component having a weight average molecular weight of less than 1000. Specifically, the positive resist composition preferably does not contain a component having a weight average molecular weight of less than 1000. The proportion is less than 0.05% by weight, preferably less than 0.01% by weight, more preferably less than 0.001% by weight. The clarity of the resist pattern can be improved if it does not substantially contain components having a weight average molecular weight of less than 1000.
  • Copolymer A contained in the positive resist composition of the present invention has a surface free energy lower than that of copolymer B by 3 mJ/m 2 or more and an EUV absorption coefficient of 55000 cm -1 or more. If so, there are no particular limitations.
  • Copolymer A is preferably a main chain-cleaved copolymer containing a halogen atom, and more preferably is a main chain-truncated copolymer containing a fluorine substituent, at least one of the halogen atoms being a fluorine atom, and the fluorine atom being included in the fluorine substituent.
  • the fluorine substituent is not particularly limited as long as it is a substituent having a fluorine atom.
  • copolymer A has the following formula (I): [In formula (I), L 1 is a divalent linking group having a fluorine atom, Ar 1 is an aromatic ring group which may have a substituent, and X 1 is a halogen atom, a cyano group, alkylsulfonyl group, alkoxy group, nitro group, acyl group, alkyl ester group, or halogenated alkyl group. ] It is preferable to have a monomer unit (I) represented by the following. If copolymer A has monomer unit (I), the clarity of the resist pattern can be improved.
  • the copolymer A also has the following formula (II) different from the monomer unit (I): [In formula (II), R 1 is an organic group having 3 to 10 fluorine atoms, and X 2 is a halogen atom, cyano group, alkylsulfonyl group, alkoxy group, nitro group, acyl group, alkyl It is an ester group or a halogenated alkyl group. ] It is preferable to further have a monomer unit (II) represented by the following. If copolymer A further has monomer unit (II), the clarity of the resist pattern can be further improved.
  • copolymer A has monomer unit (I), monomer unit (II), and monomer unit (III)
  • copolymer A has monomer unit (I), monomer unit
  • monomer unit may contain any monomer units other than the mer unit (II) and the monomer unit (III)
  • the monomer unit (I ), the monomer unit (II) and the monomer unit (III) account for a total of 90 mol % or more, preferably 100 mol % (that is, copolymer A contains monomer units ( I), containing only monomer units (II) and monomer units (III)) is more preferable.
  • the copolymer of the present invention has a monomer unit (I), a monomer unit (II), and a monomer unit (III), for example, a random copolymer, a block copolymer, It may be any ternary alternating copolymer, but preferably a ternary alternating copolymer.
  • a ternary alternating copolymer is an alternating copolymer in which monomer units (I) or monomer units (II) are copolymerized between monomer units (III). It is a combination. That is, schematically, each monomer unit is bonded like "-(III)-(I)-(III)-(II)-(III)-".
  • the monomer unit (I) has the following formula (a): [In formula (a), L 1 , Ar 1 and X 1 are the same as in formula (I). ] is a structural unit derived from monomer (a).
  • Examples of the divalent linking group having a fluorine atom that can constitute L 1 in formula (I) and formula (a) include a divalent chain alkyl group having 1 to 5 carbon atoms and having a fluorine atom. can be mentioned.
  • examples of the divalent linking group having a fluorine atom include a trifluoromethylmethylene group, a pentafluoroethylmethylene group, and a bis(trifluoromethyl)methylene group. Among these, a pentafluoroethylmethylene group and a bis(trifluoromethyl)methylene group are preferred, and a bis(trifluoromethyl)methylene group is more preferred.
  • the number of fluorine atoms in L 1 is preferably 3 or more, more preferably 4 or more, even more preferably 5 or more, and 10 or less. is preferable, and more preferably 7 or less.
  • the number of fluorine atoms in L 1 is equal to or greater than the above lower limit, the sensitivity to ionizing radiation and the like and the clarity of the resist pattern can be improved.
  • the number of fluorine atoms in L 1 is below the above upper limit, the production efficiency of copolymer A can be improved.
  • the aromatic ring group which may have a substituent and which may constitute Ar 1 in formula (I) and formula (a) includes an aromatic hydrocarbon ring group which may have a substituent, and , an aromatic heterocyclic group which may have a substituent.
  • the aromatic hydrocarbon ring group is not particularly limited, and examples thereof include a benzene ring group, a biphenyl ring group, a naphthalene ring group, an azulene ring group, an anthracene ring group, a phenanthrene ring group, a pyrene ring group, a chrysene ring group, Naphthacene ring group, triphenylene ring group, o-terphenyl ring group, m-terphenyl ring group, p-terphenyl ring group, acenaphthene ring group, coronene ring group, fluorene ring group, fluoranthrene ring group, pentacene ring group , perylene ring group, pentaphene ring group, picene ring group, pyrantrene ring group, and the like.
  • aromatic heterocyclic group examples include, without particular limitation, a furan ring group, a thiophene ring group, a pyridine ring group, a pyridazine ring group, a pyrimidine ring group, a pyrazine ring group, a triazine ring group, and an oxadiazole ring group.
  • triazole ring group imidazole ring group, pyrazole ring group, thiazole ring group, indole ring group, benzimidazole ring group, benzothiazole group, benzoxazole ring group, quinoxaline ring group, quinazoline ring group, phthalazine ring group, benzofuran ring group , a dibenzofuran ring group, a benzothiophene ring group, a dibenzothiophene ring group, a carbazole ring group, and the like.
  • the substituent that Ar 1 may have is not particularly limited, and examples thereof include an alkyl group, a fluorine atom, a fluoroalkyl group, and the like.
  • Examples of the alkyl group as a substituent that Ar 1 may have include chain alkyl groups having 1 to 6 carbon atoms such as methyl group, ethyl group, propyl group, n-butyl group, and isobutyl group.
  • examples of the fluoroalkyl group as a substituent that Ar 1 may have include fluoroalkyl groups having 1 to 5 carbon atoms such as a trifluoromethyl group, a trifluoroethyl group, and a pentafluoropropyl group.
  • Ar 1 is preferably an aromatic hydrocarbon ring group that may have a substituent, and more preferably an unsubstituted aromatic hydrocarbon ring group.
  • a benzene ring group phenyl group
  • phenyl group is more preferable.
  • halogen atom that can constitute X 1 in formula (I) and formula (a) include chlorine atom, fluorine atom, bromine atom, iodine atom, and astatine atom.
  • alkylsulfonyl group that can constitute X 1 in formula (I) and formula (a) include a methylsulfonyl group and an ethylsulfonyl group.
  • alkoxy group that can constitute X 1 in formula (I) and formula (a) include methoxy group, ethoxy group, and propoxy group.
  • acyl group that can constitute X 1 in formula (I) and formula (a) include formyl group, acetyl group, propionyl group, and the like.
  • alkyl ester group that can constitute X 1 in formula (I) and formula (a) include a methyl ester group and an ethyl ester group.
  • halogenated alkyl group examples include a halogenated methyl group having 1 or more and 3 or less halogen atoms.
  • X 1 is preferably a halogen atom, more preferably a chlorine atom.
  • the monomer (a) represented by formula (a) is ⁇ -chloroacrylate-1-phenyl-1-trifluoromethyl-2,2, 2-trifluoroethyl (ACAFPh), ⁇ -chloroacrylate-1-phenyl-2,2,2-trifluoroethyl (ACAHFPh), and ⁇ -chloroacrylate-1-(4-methoxyphenyl)-1-
  • At least one monomer selected from the group consisting of trifluoromethyl-2,2,2-trifluoroethyl (ACAFPhOMe) is preferred, and ⁇ -chloroacrylate-1-phenyl-1-trifluoromethyl-2 ,2,2-trifluoroethyl is more preferred.
  • copolymer A contains ⁇ -chloroacrylate-1-phenyl-1-trifluoromethyl-2,2,2-trifluoroethyl units, ⁇ -chloroacrylate-1-phenyl-2,2,2 - at least one unit selected from the group consisting of trifluoroethyl units, and ⁇ -chloroacrylic acid-1-(4-methoxyphenyl)-1-trifluoromethyl-2,2,2-trifluoroethyl units. It is preferable to have a mer unit, and more preferably to have an ⁇ -chloroacrylate-1-phenyl-1-trifluoromethyl-2,2,2-trifluoroethyl unit.
  • the proportion of monomer units (I) in copolymer A is preferably more than 0 mol%, and 1 mol% or more, when the total monomer units in copolymer A is 100 mol%. It is more preferably 3 mol% or more, even more preferably 5 mol% or more, even more preferably 8 mol% or more, preferably 20 mol% or less, and 15 mol% or less. It is more preferable that the amount is at least 12 mol%, and even more preferably 12 mol% or less. If the proportion of monomer units (I) in copolymer A is equal to or higher than the above lower limit when the total monomer units in copolymer A is 100 mol%, sensitivity to ionizing radiation, etc. is improved. can.
  • the proportion of monomer units (I) in copolymer A is below the above upper limit when the total monomer units in copolymer A is 100 mol%, the clarity of the resist pattern is improved. can be improved. Further, it is possible to suppress the reduction of the top of the resist pattern. Furthermore, the amount of resist residue can be reduced.
  • the monomer unit (II) different from the monomer unit (I) has the following formula (b) different from the monomer (a): [In formula (b), R 1 and X 2 are the same as in formula (II). ] is a structural unit derived from the monomer (b) represented by
  • R 1 in formula (II) and formula (b) is an organic group having 3 or more and 10 or less fluorine atoms.
  • the number of fluorine atoms in R 1 is preferably 5 or more, more preferably 6 or more, even more preferably 7 or more, even more preferably 8 or more, and 9 or less. It is preferable that there be.
  • the number of fluorine atoms in R 1 is at least the above lower limit, sensitivity to ionizing radiation and the like and clarity of the resist pattern can be improved. Further, if the number of fluorine atoms in R 1 is 8 or more, the production efficiency of copolymer A can be improved.
  • the number of carbon atoms in R 1 in formula (II) and formula (b) is preferably 2 or more and 10 or less, more preferably 5 or less. If the number of carbon atoms is at least the above lower limit, the solubility in the developer can be sufficiently improved. On the other hand, if the carbon number is below the above upper limit, the clarity of the resist pattern can be sufficiently ensured.
  • the organic group in R 1 preferably does not have an aromatic ring, and is more preferably chain-like.
  • organic groups include fluoroalkyl groups such as (b-1) to (b-31) below; fluoroalkoxyalkyl groups such as (b-32) to (b-55) below; Examples include fluoroalkoxyalkenyl groups such as ethoxyvinyl groups; and the like.
  • the organic group in R 1 is preferably a fluoroalkyl group, such as the fluoroalkyl group (2,2,2-trifluoroethyl group) in (b-13) and the fluoroalkyl group in (b-20).
  • fluoroalkyl group (2,2,3,3,3-pentafluoropropyl group), fluoroalkyl group (2,2,3,3,4,4,4-heptafluorobutyl group) of (b-25), or (b-31) is more preferably a fluoroalkyl group (2,2,3,3,4,4,5,5,5-nonafluoropentyl group), and 2,2,3,3,3- Pentafluoropropyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, or 2,2,3,3,4,4,5,5,5-nonafluoropentyl group More preferably, it is a 2,2,3,3,4,4,4-heptafluorobutyl group or a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group. is even more preferred, and 2,2,3,3,4,4,5,5,5-nonafluoropentyl group is even more preferred.
  • halogen atom that can constitute X 2 in formula (II) and formula (b) include a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, an astatine atom, and the like.
  • alkylsulfonyl group that can constitute X 2 in formula (II) and formula (b) include a methylsulfonyl group and an ethylsulfonyl group.
  • alkoxy group that can constitute X 2 in formula (II) and formula (b) include methoxy group, ethoxy group, and propoxy group.
  • acyl group that can constitute X 2 in formula (II) and formula (b) include formyl group, acetyl group, propionyl group, and the like.
  • alkyl ester group that can constitute X 2 in formula (II) and formula (b) include a methyl ester group and an ethyl ester group.
  • halogenated alkyl group that can constitute X 2 in formula (II) and formula (b) include a halogenated methyl group having 1 or more and 3 or less halogen atoms.
  • X 2 is preferably a halogen atom, more preferably a chlorine atom, and even more preferably the same as X 1 .
  • monomer (b) represented by formula (b) includes, for example, ⁇ -chloroacrylic acid 2,2,2-trifluoroethyl (ACATFE), ⁇ -chloroacrylic acid 2,2 , 3,3,3-pentafluoropropyl (ACAPFP), ⁇ -chloroacrylic acid 3,3,4,4,4-pentafluorobutyl, ⁇ -chloroacrylic acid 2,2,3,3,4,4, 5,5,5-nonafluoropentyl, ⁇ -chloroacrylate 1H-1-(trifluoromethyl)trifluoroethyl, ⁇ -chloroacrylate 1H,1H,3H-hexafluorobutyl, ⁇ -chloroacrylate 1, ⁇ -chloroacrylics such as 2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl and 2,2,3,3,4,4,4-heptafluorobutyl ⁇ -chloroacrylate (ACAHF
  • ⁇ -chloroacrylic acid fluoroalkoxyalkenyl ester and the like.
  • ⁇ -chloroacrylic acid fluoroalkyl ester is preferred because it can improve sensitivity to ionizing radiation, etc.
  • ⁇ -chloroacrylic acid 2,2,2-trifluoroethyl ester, ⁇ -chloroacrylic acid 2,2,3 , 3,3-pentafluoropropyl, ⁇ -chloroacrylic acid 2,2,3,3,4,4,4-heptafluorobutyl, ⁇ -chloroacrylic acid 2,2,3,3,4,4, 5,5,5-nonafluoropentyl is more preferred, 2,2,3,3,3-pentafluoropropyl ⁇ -chloroacrylate, 2,2,3,3,4,4,4 ⁇ -chloroacrylate -heptafluorobutyl is more preferred, and ⁇ -chloroacrylic acid 2,2,3,3,4,4,4-heptafluorobutyl
  • copolymer A preferably has ⁇ -chloroacrylic acid fluoroalkyl ester units, ⁇ -chloroacrylic acid 2,2,2-trifluoroethyl units, ⁇ -chloroacrylic acid 2,2,3, 3,3-pentafluoropropyl unit, ⁇ -chloroacrylic acid 2,2,3,3,4,4,4-heptafluorobutyl unit, and ⁇ -chloroacrylic acid 2,2,3,3,4, It is more preferable to have at least one monomer unit selected from the group consisting of 4,5,5,5-nonafluoropentyl units, and ⁇ -chloroacrylic acid 2,2,3,3,3-pentyl Fluoropropyl units, ⁇ -chloroacrylic acid 2,2,3,3,4,4,4-heptafluorobutyl units, and ⁇ -chloroacrylic acid 2,2,3,3,4,4,5,5 , 5-nonafluoropentyl unit, and ⁇ -chloroacrylic acid 2,
  • a monomer unit of at least one of a fluorobutyl unit and an ⁇ -chloroacrylic acid 2,2,3,3,4,4,5,5,5-nonafluoropentyl unit It is even more preferable to have a 2,2,3,3,4,4,5,5,5-nonafluoropentyl -chloroacrylate unit.
  • the proportion of monomer units (II) in copolymer A is preferably 20 mol% or more, and 30 mol% or more, when the total monomer units in copolymer A is 100 mol%. It is more preferably 35 mol% or more, even more preferably 38 mol% or more, preferably 70 mol% or less, more preferably 60 mol% or less, and 50 mol% or less. It is even more preferable that it is 45 mol% or less, even more preferably that it is 42 mol% or less. If the proportion of monomer units (II) in copolymer A is below the above upper limit when the total monomer units in copolymer A is 100 mol%, the clarity of the resist pattern is improved. can.
  • copolymer A has monomer unit (I) and monomer unit (II)
  • the relationship between monomer unit (I) and monomer unit (II) in copolymer A is The total proportion is preferably 45 mol% or more, more preferably 47 mol% or more, and preferably 70 mol% or less, when the total monomer units in copolymer A are 100 mol%. , more preferably 60 mol% or less, and still more preferably 55 mol% or less.
  • the alkyl group that can constitute R 2 in formula (III) and formula (c) is not particularly limited, and includes alkyl groups having 1 or more and 5 or less carbon atoms. Among these, the alkyl group that can constitute R 2 is preferably a methyl group or an ethyl group.
  • the unsubstituted alkyl group that can constitute R 3 and R 4 in formula (III) and formula (c) is not particularly limited, and includes unsubstituted alkyl groups having 1 to 5 carbon atoms. .
  • the unsubstituted alkyl group that can constitute R 3 and R 4 is preferably a methyl group or an ethyl group.
  • the fluorine atom-substituted alkyl group that can constitute R 3 and R 4 in formula (III) and formula (c) is not particularly limited, and the alkyl group in which some or all of the hydrogen atoms in the alkyl group are substituted with Examples include groups having a structure substituted with a fluorine atom.
  • each R 3 may be the same or different from each other.
  • all of the plurality of R 3 and/or R 4 in formula (III) and formula (c) are hydrogen atoms or unsubstituted alkyl groups. It is preferably a hydrogen atom or an unsubstituted alkyl group having 1 or more and 5 or less carbon atoms, and even more preferably a hydrogen atom.
  • the monomer (c) represented by formula (c) is not particularly limited, and examples thereof include ⁇ -methylstyrene (AMS) such as the following monomers (c-1) to (c-11). ) and its derivatives (eg, 4-fluoro- ⁇ -methylstyrene: 4FAMS).
  • AMS ⁇ -methylstyrene
  • 4FAMS 4-fluoro- ⁇ -methylstyrene
  • the monomer (c) represented by formula (c) is as follows: ⁇ -methylstyrene (c-1) or 4-fluoro- ⁇ -methylstyrene (c-2) is preferred, and ⁇ -methylstyrene is more preferred. That is, copolymer A preferably has an ⁇ -methylstyrene unit or a 4-fluoro- ⁇ -methylstyrene unit, and preferably has an ⁇ -methylstyrene unit.
  • the proportion of monomer units (III) in copolymer A is not particularly limited, and should be, for example, 30 mol% or more when the total monomer units in copolymer A is 100 mol%. It is preferably 40 mol% or more, more preferably 45 mol% or more, for example, it can be 70 mol% or less, preferably 60 mol% or less, and more preferably 55 mol% or less. , more preferably 53 mol% or less.
  • the EUV absorption coefficient of copolymer A is 55,000 cm ⁇ 1 or more.
  • the EUV absorption coefficient of copolymer A is preferably 60,000 cm -1 or more, more preferably 70,000 cm -1 or more.
  • the clarity of the resist pattern can be improved.
  • the EUV absorption coefficient of copolymer A is, for example, 150,000 cm -1 or less, may be 100,000 cm -1 or less, may be 90,000 cm -1 or less, may be 80,000 cm -1 or less, or may be 75,000 cm -1 or less. Note that the EUV absorption coefficient can be adjusted by changing the type and proportion of monomer units constituting the copolymer.
  • the surface free energy of copolymer A is preferably 18 mJ/m 2 or more, more preferably 19 mJ/m 2 or more, even more preferably 19.5 mJ/m 2 or more, and 27 mJ/m 2 or more. It is preferably 2 or less, more preferably 26 mJ/m 2 or less, even more preferably 25 mJ/m 2 or less, even more preferably 24 mJ/m 2 or less, and even more preferably 22 mJ/m 2 or less. It is even more preferable that Note that the surface free energy can be adjusted by changing the type and ratio of monomer units that constitute the copolymer.
  • the weight average molecular weight (Mw) of copolymer A is preferably 10,000 or more, more preferably 17,000 or more, even more preferably 25,000 or more, preferably 250,000 or less, and 180,000 or less. It is more preferably 80,000 or less, even more preferably 50,000 or less. If the weight average molecular weight (Mw) of the copolymer A is equal to or higher than the above lower limit, it is possible to suppress the solubility of the resist film in the developer from increasing excessively with a low irradiation dose. On the other hand, if the weight average molecular weight (Mw) of copolymer A is below the above upper limit, a positive resist composition can be easily prepared. In addition, in this specification, "weight average molecular weight" can be measured using the method described in Examples.
  • the number average molecular weight (Mn) of copolymer A is preferably 7,000 or more, more preferably 10,000 or more, even more preferably 20,000 or more, preferably 150,000 or less, and 100,000 or less. It is more preferably 70,000 or less, even more preferably 40,000 or less. If the number average molecular weight (Mn) of copolymer A is at least the above lower limit, it is possible to further suppress the solubility of the resist film in the developer from increasing excessively at a low irradiation dose, and the clarity is further improved. A resist pattern can be formed.
  • the number average molecular weight (Mn) of copolymer A is below the above upper limit, a positive resist composition can be prepared more easily.
  • the "number average molecular weight" can be measured as a standard polystyrene equivalent value using gel permeation chromatography.
  • molecular weight distribution (Mw/Mn)- The molecular weight distribution (Mw/Mn) of copolymer A is preferably 1.10 or more, more preferably 1.20 or more, even more preferably 1.45 or more, and 1.80 or less. It is preferable that it is, it is more preferable that it is 1.70 or less, and it is still more preferable that it is 1.65 or less. If the molecular weight distribution (Mw/Mn) of copolymer A is at least the above lower limit, the ease of manufacturing copolymer A can be improved. On the other hand, if the molecular weight distribution (Mw/Mn) of copolymer A is below the above upper limit, the clarity of the resulting resist pattern can be further improved. In this specification, "molecular weight distribution” can be determined by calculating the ratio of weight average molecular weight to number average molecular weight (weight average molecular weight/number average molecular weight).
  • the content of copolymer A in the positive resist composition is preferably 1% by mass or more, and preferably 5% by mass or more, when the total of copolymer A and copolymer B is 100% by mass. It is more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 40% by mass or less, and more preferably 30% by mass or less. , more preferably 25% by mass or less. If the proportion of copolymer A in the positive resist composition is equal to or greater than the above lower limit when the total of copolymer A and copolymer B is 100% by mass, the clarity of the resist pattern can be improved. .
  • Copolymer A having a monomer unit (I), a monomer unit (II), and a monomer unit (III) is, for example, a monomer (a) and a monomer (b).
  • the obtained copolymer A is recovered, It can be prepared by optional purification.
  • the composition, molecular weight distribution, number average molecular weight, and weight average molecular weight of copolymer A can be adjusted by changing the polymerization conditions and purification conditions. Specifically, for example, the number average molecular weight and weight average molecular weight can be increased by lowering the polymerization temperature. Further, the number average molecular weight and weight average molecular weight can be increased by shortening the polymerization time. Furthermore, by purification, the molecular weight distribution can be made smaller.
  • the monomer composition used for preparing copolymer A includes, for example, monomer (a), monomer (b), monomer (c), and copolymerized with these monomers.
  • a mixture of a monomer component containing any possible monomer, an optionally usable solvent, an optionally usable polymerization initiator, and an optionally added additive can be used.
  • the monomer composition can then be polymerized using known methods. Among these, it is preferable to use cyclopentanone, water, etc. as the solvent. Further, as the polymerization initiator, it is preferable to use, for example, azobisisobutyronitrile.
  • the polymer obtained by polymerizing the monomer composition is not particularly limited. After adding a good solvent such as tetrahydrofuran to a solution containing the polymer, the solution to which the good solvent has been added is mixed with methanol, ethanol, It can be recovered by solidifying the polymer by dropping it into a poor solvent such as 1-propanol, 1-butanol, 1-pentanol, or hexane.
  • a good solvent such as tetrahydrofuran
  • the purification method used to purify the obtained polymer is not particularly limited, and includes known purification methods such as reprecipitation and column chromatography. Among these, it is preferable to use a reprecipitation method as a purification method. Note that the purification of the polymer may be repeated multiple times.
  • Purification of a polymer by the reprecipitation method can be carried out, for example, by dissolving the obtained polymer in a good solvent such as tetrahydrofuran, and then mixing the obtained solution with a good solvent such as tetrahydrofuran and methanol, ethanol, 1-propanol, 1- This is preferably carried out by dropping a portion of the polymer by dropping it into a mixed solvent with a poor solvent such as butanol, 1-pentanol, or hexane.
  • a good solvent such as tetrahydrofuran
  • the resulting copolymer A can be obtained by changing the types and mixing ratio of the good and poor solvents.
  • the molecular weight distribution, number average molecular weight and weight average molecular weight of can be easily adjusted. Specifically, for example, the higher the proportion of the good solvent in the mixed solvent, the larger the molecular weight of the copolymer A precipitated in the mixed solvent.
  • copolymer A When purifying a polymer by the reprecipitation method, copolymer A may be a polymer precipitated in a mixed solvent of a good solvent and a poor solvent, or a polymer precipitated in a mixed solvent of a good solvent and a poor solvent, as long as it satisfies the desired properties.
  • a polymer that did not precipitate in the step (that is, a polymer dissolved in the mixed solvent) may be used.
  • the polymer that did not precipitate in the mixed solvent can be recovered from the mixed solvent using a known method such as concentration to dryness.
  • Copolymer B contained in the positive resist composition of the present invention is not particularly limited as long as it has a surface free energy higher than the surface energy of copolymer A by 3 mJ/m 2 or more.
  • Copolymer B is preferably a main chain-cleaved copolymer containing a halogen atom, and more preferably is a main chain-truncated copolymer containing a fluorine substituent, at least one of the halogen atoms being a fluorine atom, and the fluorine atom being included in the fluorine substituent.
  • the fluorine substituent is not particularly limited as long as it is a substituent having a fluorine atom.
  • copolymer B has the following formula (IV): [In formula (IV), L 2 is a divalent linking group having a fluorine atom, Ar 2 is an aromatic ring group which may have a substituent, and X 3 is a halogen atom, a cyano group, alkylsulfonyl group, alkoxy group, nitro group, acyl group, alkyl ester group, or halogenated alkyl group.
  • a monomer unit (IV) represented by The following formula (V): [In formula (V), R 5 is an alkyl group, R 6 is a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carboxyl group, or a halogenated carboxyl group, and R 7 is It is a hydrogen atom, an unsubstituted alkyl group, or an alkyl group substituted with a fluorine atom, r and s are integers from 0 to 5, and r+s 5. It is preferable to have a monomer unit (V) represented by the following. If copolymer B has monomer units (IV) and monomer units (V), the clarity of the resist pattern can be improved.
  • copolymer B when copolymer B has monomer units (IV) and monomer units (V), copolymer B has monomer units other than monomer units (IV) and monomer units (V). Although it may contain any monomer units (excluding monomer unit (II)), monomer units (IV) and The proportion occupied by the monomer units (V) is preferably 90 mol% or more in total, and is 100 mol% (that is, the copolymer B contains monomer units (IV) and monomer units (V) It is more preferable to include only Here, the copolymer B may be, for example, a random copolymer, a block copolymer, a ternary alternating copolymer, etc., but is preferably a ternary alternating copolymer.
  • the divalent linking group having a fluorine atom that can constitute L 2 in formula (IV) and formula (d) is a fluorine atom that can constitute L 1 in formula (I) and formula (a). Examples include groups similar to the divalent linking group having .
  • the aromatic ring group which may have a substituent and which may constitute Ar 2 in formula (IV) and formula (d) may constitute Ar 1 in formula (I) and formula (a). , and the same groups as aromatic ring groups which may have substituents.
  • halogen atom that can constitute X 3 in formula (IV) and formula (d) examples include the same groups as the halogen atom that can constitute X 1 in formula (I) and formula (a).
  • alkylsulfonyl group that can constitute X 3 in formula (IV) and formula (d) examples include the same groups as the alkylsulfonyl group that can constitute X 1 in formula (I) and formula (a). .
  • alkoxy group that can constitute X 3 in formula (IV) and formula (d) examples include the same groups as the alkoxy group that can constitute X 1 in formula (I) and formula (a).
  • Examples of the acyl group that can constitute X 3 in formula (IV) and formula (d) include the same groups as the acyl group that can constitute X 1 in formula (I) and formula (a).
  • alkyl ester group that can constitute X 3 in formula (IV) and formula (d) examples include the same groups as the alkyl ester group that can constitute X 1 in formula (I) and formula (a). .
  • halogenated alkyl group that can constitute X 3 in formula (IV) and formula (d) examples include the same groups as the halogenated alkyl group that can constitute X 1 in formula (I) and formula (a). Can be mentioned.
  • X 3 is preferably a halogen atom, more preferably a chlorine atom, and even more preferably the same as X 1 .
  • the proportion of monomer units (IV) in copolymer B is not particularly limited, and should be, for example, 30 mol% or more when the total monomer units in copolymer B is 100 mol%. It is preferably 40 mol% or more, more preferably 45 mol% or more, for example, it can be 70 mol% or less, preferably 60 mol% or less, and more preferably 55 mol% or less. .
  • the monomer unit (V) is represented by the following formula (e): [In formula (e), R 5 to R 7 and r and s are the same as in formula (V). ) is a structural unit derived from monomer (e).
  • the alkyl group that can constitute R 5 and R 6 in formula (V) and formula (e) is not particularly limited, and includes, for example, an unsubstituted alkyl group having 1 to 5 carbon atoms.
  • the alkyl group that can constitute R 5 and R 6 is preferably a methyl group or an ethyl group.
  • the halogen atom that can constitute R 6 in formula (V) and formula (e) is not particularly limited, and examples thereof include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Among these, a fluorine atom is preferred as the halogen atom.
  • the halogenated alkyl group that can constitute R 6 in formula (V) and formula (e) is not particularly limited, and includes, for example, a fluoroalkyl group having 1 to 5 carbon atoms.
  • the halogenated alkyl group is preferably a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a trifluoromethyl group.
  • the unsubstituted alkyl group that can constitute R 7 in formula (V) and formula (e) is not particularly limited, and includes unsubstituted alkyl groups having 1 to 5 carbon atoms.
  • the unsubstituted alkyl group that can constitute R 7 is preferably a methyl group or an ethyl group.
  • the alkyl group substituted with a fluorine atom that can constitute R 7 in formula (V) and formula (e) is not particularly limited, and the alkyl group in which some or all of the hydrogen atoms in the alkyl group are replaced with a fluorine atom is not particularly limited. Examples include groups having a substituted structure.
  • R 6 and/or R 7 in formula (V) and formula (e) are all hydrogen atoms.
  • the monomer (e) represented by the formula (e) is not particularly limited, and examples thereof include ⁇ -methylstyrene (AMS) such as the following monomers (e-1) to (e-12). ) and derivatives thereof.
  • AMS ⁇ -methylstyrene
  • copolymer B preferably has ⁇ -methylstyrene units.
  • the proportion of monomer units (V) in copolymer B is not particularly limited, and may be, for example, 30 mol% or more when the total monomer units in copolymer B is 100 mol%. It is preferably 40 mol% or more, more preferably 45 mol% or more, for example, it can be 70 mol% or less, preferably 60 mol% or less, and more preferably 55 mol% or less. .
  • the EUV absorption coefficient of copolymer B is preferably 25,000 cm -1 or more, more preferably 30,000 cm -1 or more, even more preferably 40,000 cm -1 or more, and preferably 45,000 cm -1 or more. Even more preferably, it is 50,000 cm -1 or more, even more preferably less than 55,000 cm -1 , and even more preferably 54,000 cm -1 or less.
  • the EUV absorption coefficient of copolymer B is at least the above lower limit and at most the above upper limit, the clarity of the resist pattern can be improved.
  • the surface free energy of copolymer B is preferably 28 mJ/m 2 or more, more preferably 29 mJ/m 2 or more, even more preferably 30 mJ/m 2 or more, and 35 mJ/m 2 or less. It is preferably 34 mJ/m 2 or less, more preferably 33 mJ/m 2 or less, and even more preferably 33 mJ/m 2 or less.
  • the weight average molecular weight (Mw) of copolymer B is preferably 100,000 or more, more preferably 125,000 or more, even more preferably 150,000 or more, preferably 600,000 or less, and 500,000 or less. It is more preferable that the number is 300,000 or less, and even more preferably 300,000 or less.
  • the number average molecular weight (Mn) of copolymer B is preferably 100,000 or more, more preferably 110,000 or more, preferably 300,000 or less, more preferably 200,000 or less, and 150,000 or less. It is even more preferable that there be.
  • the molecular weight distribution (Mw/Mn) of copolymer B is preferably 1.20 or more, more preferably 1.25 or more, even more preferably 1.30 or more, and 2.00 or less. It is preferable that it is, it is more preferable that it is 1.80 or less, and it is still more preferable that it is 1.60 or less.
  • the content of copolymer B in the positive resist composition is preferably 60% by mass or more, and 70% by mass or more, when the total of copolymer A and copolymer B is 100% by mass. It is more preferably 75% by mass or more, still more preferably 99% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass, It is even more preferably 85% by mass or less. If the proportion of copolymer B in the positive resist composition is equal to or higher than the above lower limit when the total of copolymer A and copolymer B is 100% by mass, sensitivity to ionizing radiation, etc. can be improved. .
  • copolymer B having the above-mentioned monomer unit (IV) and monomer unit (V) includes monomer (d), monomer (e), and these monomers. It can be prepared by polymerizing a monomer composition containing a copolymerizable monomer, and then collecting the resulting copolymer and optionally purifying it.
  • the polymerization method and the purification method are not particularly limited, and can be the same as the method described in the section of "Method for Preparing Copolymer A" above.
  • the polymerization method and purification method conventionally known methods such as suspension polymerization and solution polymerization can also be used.
  • a polymerization initiator may be used.
  • the total proportion of copolymer A and copolymer B in the positive resist composition may be 0.5% by mass or more when the total of all components of the positive resist composition is 100% by mass. It is preferably 1% by mass or more, more preferably 1.5% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, and 5% by mass. It is more preferable that it is the following.
  • the solvent is not particularly limited as long as it can dissolve copolymer A and copolymer B, and known solvents such as those described in Japanese Patent No. 5938536 can be used.
  • examples of the solvent include anisole, propylene glycol monomethyl ether acetate (PGMEA), cyclopentanone, and cyclohexanone.
  • PMEA propylene glycol monomethyl ether acetate
  • cyclopentanone cyclohexanone
  • a positive resist composition can be prepared by mixing copolymer A, copolymer B, a solvent, and any known additives that can be used.
  • the mixing method is not particularly limited, and any known method may be used.
  • the mixture may be prepared by mixing each component and then filtering the mixture.
  • the method for filtering the mixture is not particularly limited, and can be filtered using a filter, for example.
  • the filter is not particularly limited, and examples include fluorocarbon-based, cellulose-based, nylon-based, polyester-based, and hydrocarbon-based filtration membranes. Among these, from the viewpoint of effectively preventing impurities such as metals from being mixed into the positive resist composition from metal piping etc. that may be used during the preparation of copolymer A and copolymer B, it is important to configure a filter.
  • Preferred materials include polyethylene, polypropylene, polytetrafluoroethylene, polyfluorocarbons such as Teflon (registered trademark), tetrafluoroethylene/perfluoroalkyl vinyl ether copolymers (PFA), nylon, and composite films of polyethylene and nylon.
  • a filter for example, the one disclosed in US Pat. No. 6,103,122 may be used. Further, as a filter, a commercially available filter such as Zeta Plus (registered trademark) 40Q manufactured by CUNO Incorporated may be used. Furthermore, the filter may contain a strongly cationic or weakly cationic ion exchange resin.
  • the average particle size of the ion exchange resin is not particularly limited, but is preferably 2 ⁇ m or more and 10 ⁇ m or less.
  • cation exchange resins include sulfonated phenol-formaldehyde condensates, sulfonated phenol-benzaldehyde condensates, sulfonated styrene-divinylbenzene copolymers, sulfonated methacrylic acid-divinylbenzene copolymers, and Other types of sulfonic acid or carboxylic acid group-containing polymers may be mentioned.
  • the cation exchange resin is provided with H + counterions, NH 4 + counterions or alkali metal counterions, such as K + and Na + counterions.
  • the cation exchange resin preferably has a hydrogen counter ion.
  • Such cation exchange resins include Microlite® PrCH from Purolite, a sulfonated styrene-divinylbenzene copolymer with an H + counterion.
  • Such cation exchange resins are commercially available as AMBERLYST® from Rohm and Haas.
  • the pore size of the filter is preferably 0.001 ⁇ m or more and 1 ⁇ m or less. When the pore size of the filter is within the above range, it is possible to sufficiently prevent impurities such as metals from being mixed into the positive resist composition.
  • the resist pattern forming method includes a step of forming a resist film using the above-described positive resist composition of the present invention (resist film forming step), a step of exposing the resist film (exposure step), and a step of exposing the resist film to light.
  • the method includes at least a step of developing the resist film (developing step).
  • the resist pattern forming method may further include steps other than the above-described resist film forming step, exposure step, and development step.
  • the resist pattern forming method may include, before the resist film forming step, a step of forming a lower layer film on the substrate on which the resist film is formed (lower layer film forming step). Further, the resist pattern forming method may include a step of heating the exposed resist film (post-exposure bake (PEB) step) between the exposure step and the development step. Further, the resist pattern forming method may further include a step of removing the developer (developer removing step) after the developing step. After the resist pattern is formed by the resist pattern forming method, the method may further include a step of etching the underlying film and/or the substrate (etching step). In such a resist pattern forming method, since the positive resist composition of the present invention is used as the positive resist composition, a resist pattern with excellent clarity can be formed.
  • PEB post-exposure bake
  • a lower layer film is formed on the substrate.
  • the surface of the substrate is made hydrophobic. Thereby, the affinity between the substrate and the resist film can be increased, and the adhesion between the substrate and the resist film can be improved.
  • the lower layer film may be an inorganic lower layer film or an organic lower film.
  • the inorganic lower layer film can be formed by applying an inorganic material onto a substrate and performing baking or the like.
  • the inorganic material include silicon-based materials.
  • the organic lower layer film can be formed by applying an organic material onto the substrate to form a coating film and drying it.
  • the organic material is not limited to those that are sensitive to light or electron beams, and for example, resist materials and resin materials commonly used in the semiconductor field, liquid crystal field, etc. can be used.
  • the organic material is preferably a material that can form an organic lower layer film that can be etched, especially dry etched.
  • the organic material is preferably a material that can form an organic lower layer film that can be etched by oxygen plasma etching or the like. Examples of the organic material used to form the organic lower layer film include AL412 manufactured by Brewer Science.
  • the above-mentioned organic material can be applied by a conventionally known method using spin coating, a spinner, or the like.
  • the method for drying the coating film may be any method as long as it can evaporate the solvent contained in the organic material, such as baking.
  • the baking conditions are not particularly limited, but the baking temperature is preferably 80°C or more and 300°C or less, more preferably 200°C or more and 300°C or less.
  • the baking time is preferably 30 seconds or more, more preferably 60 seconds or more, preferably 500 seconds or less, more preferably 400 seconds or less, and preferably 300 seconds or less. It is more preferable, and particularly preferably 180 seconds or less.
  • the thickness of the lower layer film after drying the coating film is not particularly limited, but is preferably 10 nm or more and 100 nm or less.
  • the substrate on which the lower layer film or the resist film can be formed in the resist pattern forming method is not particularly limited, and includes an insulating layer and a copper foil provided on the insulating layer, which are used for manufacturing printed circuit boards, etc. and a mask blank in which a light-shielding layer is formed on the substrate, etc. can be used.
  • Examples of the material of the substrate include metals (silicon, copper, chromium, iron, aluminum, etc.), glass, inorganic materials such as titanium oxide, silicon dioxide (SiO 2 ), silica, and mica; nitrides such as SiN; Oxynitrides: Examples include organic substances such as acrylic, polystyrene, cellulose, cellulose acetate, and phenolic resin. Among these, metal is preferable as the material of the substrate.
  • a cylindrical structure can be formed by using, for example, a silicon substrate, a silicon dioxide substrate, or a copper substrate, preferably a silicon substrate or a silicon dioxide substrate, as the substrate.
  • the size and shape of the substrate are not particularly limited. Note that the surface of the substrate may be smooth, may have a curved surface or an uneven shape, or may be a substrate in the shape of a flake.
  • the surface of the substrate may be subjected to surface treatment if necessary.
  • the surface of the substrate can be treated using a silane coupling agent that can react with the hydroxyl group. This changes the surface layer of the substrate from hydrophilic to hydrophobic, thereby increasing the adhesion between the substrate and the underlying film or between the substrate and the resist layer.
  • the silane coupling agent is not particularly limited, but hexamethyldisilazane is preferred.
  • the positive resist composition of the present invention is applied onto a workpiece such as a substrate to be processed using a resist pattern (on top of the lower film if a lower film is formed). , the applied positive resist composition is dried to form a resist film.
  • the method for applying and drying the positive resist composition is not particularly limited, and methods commonly used for forming resist films can be used. Among these, heating (prebaking) is preferred as the drying method. Further, from the viewpoint of improving the film density of the resist film, the prebaking temperature is preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 140°C or higher. In order to reduce changes in the molecular weight and molecular weight distribution of copolymer A and copolymer B in the resist film before and after prebaking, the prebaking temperature is preferably 250°C or lower, and 220°C or lower. It is more preferable that the temperature be 200° C. or less.
  • the pre-bake time is preferably 10 seconds or more, more preferably 20 seconds or more, and even more preferably 30 seconds or more. preferable.
  • the prebaking time is preferably 10 minutes or less, and 5 minutes or less. More preferably, the duration is 3 minutes or less.
  • the resist film formed in the resist film forming step is irradiated with ionizing radiation or the like to draw a desired pattern.
  • a known drawing device such as an electron beam drawing device or an EUV exposure device can be used.
  • ⁇ Post-exposure bake process> In the post-exposure baking step, which can be performed optionally, the resist film exposed in the exposure step is heated. By performing a post-exposure baking step, the surface roughness of the resist pattern can be reduced.
  • the heating temperature is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 90°C or higher, preferably 200°C or lower, and 170°C or lower. It is more preferable that the temperature is 150°C or less. When the heating temperature is within the above range, the surface roughness of the resist pattern can be favorably reduced while improving the clarity of the resist pattern.
  • the time for heating the resist film in the post-exposure baking step is preferably 10 seconds or more, more preferably 20 seconds or more, and even more preferably 30 seconds or more. If the heating time is 10 seconds or more, the surface roughness of the resist pattern can be sufficiently reduced while further improving the clarity of the resist pattern. On the other hand, from the viewpoint of production efficiency, the heating time is, for example, preferably 10 minutes or less, more preferably 5 minutes or less, and even more preferably 3 minutes or less.
  • the method of heating the resist film in the post-exposure baking step is not particularly limited, and examples include a method of heating the resist film with a hot plate, a method of heating the resist film in an oven, and a method of blowing hot air onto the resist film. .
  • the exposed resist film (or the exposed and heated resist film when a post-exposure bake step is performed) is developed to form a developed film on the workpiece.
  • the resist film can be developed by, for example, bringing the resist film into contact with a developer.
  • the method of bringing the resist film into contact with the developer is not particularly limited, and known methods such as immersing the resist film in the developer or applying the developer to the resist film can be used.
  • the developer can be appropriately selected depending on the properties of copolymer A and copolymer B. Specifically, when selecting a developer, it is preferable to select a developer that does not dissolve the resist film before the exposure process, but can dissolve the exposed portion of the resist film that has undergone the exposure process. Moreover, one type of developer may be used alone, or two or more types may be used as a mixture in any ratio.
  • Examples of the developer include 1,1,1,2,3,4,4,5,5,5-decafluoropentane (CF 3 CFHCFHCF 2 CF 3 ), 1,1,1,2,2 ,3,3,4,4,5,5,6,6-tridecafluorohexane, 1,1,1,2,2,3,4,5,5,5-decafluoropentane, 1,1, Hydrofluorocarbons such as 1,3,3-pentafluorobutane, 1,1,1,2,2,3,3,4,4-nonafluorohexane, 2,2-dichloro-1,1,1-trifluoro Ethane, 1,1-dichloro-1-fluoroethane, 1,1-dichloro-2,2,3,3,3-pentafluoropropane (CF 3 CF 2 CHCl 2 ), 1,3-dichloro-1,1 , 2,2,3-pentafluoropropane (CClF 2 CF 2 CHClF) and other hydrochlorofluorocarbons, methyl non
  • the temperature of the developer during development is not particularly limited, but can be, for example, 5° C. or higher and 40° C. or lower. Further, the developing time can be, for example, 10 seconds or more and 4 minutes or less.
  • the developer removal step optionally included in the resist pattern forming method, the developer is removed from the developed resist film to form a resist pattern on the workpiece.
  • the developer can be removed by air blowing using a gas such as nitrogen, or by rinsing using a rinsing liquid.
  • the method of bringing the developed resist film into contact with the rinsing liquid is not particularly limited, and may include dipping the resist film in the rinsing liquid, applying the rinsing liquid to the resist film, etc. Known techniques can be used.
  • the rinsing liquid include, in addition to those similar to the developing liquids exemplified in the "Developing Step" section, hydrocarbon solvents such as octane and heptane, and water.
  • the rinsing liquid may contain a surfactant.
  • the temperature of the rinsing liquid during rinsing is not particularly limited, but can be, for example, 5° C. or higher and 40° C. or lower. Further, the rinsing time can be, for example, 5 seconds or more and 3 minutes or less.
  • the developer solution and rinse solution described above may each be filtered before use.
  • Examples of the filtration method include the filtration method using a filter as described in the above section of "Preparation of positive resist composition.”
  • the underlying film and/or substrate is etched using the above-described resist pattern as a mask to form a pattern on the underlying film and/or substrate.
  • the number of times of etching is not particularly limited, and may be one or more times.
  • the etching may be dry etching or wet etching, but dry etching is preferable. Dry etching can be performed using a known dry etching device. The etching gas used for dry etching can be appropriately selected depending on the elemental composition of the underlying film and substrate to be etched.
  • Etching gases include, for example, fluorine-based gases such as CHF 3 , CF 4 , C 2 F 6 , C 3 F 8 , SF 6 ; chlorine-based gases such as Cl 2 and BCl 3 ; O 2 , O 3 , H 2 O, etc.
  • Oxygen gas H2 , NH3 , CO , CO2, CH4 , C2H2 , C2H4 , C2H6 , C3H4 , C3H6 , C3H8 , HF , HI, HBr, HCl, NO, BCl 3 and other reducing gases; He, N 2 , Ar and other inert gases, and the like. These gases may be used alone or in combination of two or more.
  • an oxygen-based gas is usually used for dry etching of an inorganic lower layer film. Furthermore, for dry etching of the substrate, a fluorine-based gas is usually used, and a mixture of a fluorine-based gas and an inert gas is preferably used.
  • the underlying film remaining on the substrate may be removed before or after etching the substrate.
  • the lower layer film may be a lower layer film with a pattern formed thereon, or may be a lower layer film without a pattern formed thereon.
  • the lower layer film may be removed by bringing a liquid such as a basic liquid or an acidic liquid, preferably a basic liquid, into contact with the lower layer film.
  • the basic liquid is not particularly limited, and includes, for example, alkaline hydrogen peroxide solution.
  • the method of removing the lower layer film by wet peeling using alkaline hydrogen peroxide solution is not particularly limited as long as the lower layer film and the alkaline hydrogen peroxide solution can be in contact for a certain period of time under heating conditions.
  • Examples include a method of immersing the base film in heated alkaline hydrogen peroxide solution, a method of spraying alkaline hydrogen peroxide solution onto the lower layer film in a heated environment, and a method of coating the lower layer film with heated alkaline hydrogen peroxide solution. After performing any of these methods, the substrate is washed with water and dried to obtain a substrate from which the underlying film has been removed.
  • the resist pattern forming method is not limited to the method shown in the following example.
  • An example of a resist pattern forming method is a resist pattern forming method using electron beam or EUV, which includes the above-mentioned lower layer film forming step, resist film forming step, exposure step, developing step, and developer removing step. including.
  • an example of the etching method uses a resist pattern formed by a resist pattern forming method as a mask, and includes an etching step.
  • an inorganic material is applied onto the substrate and baked to form an inorganic lower layer film.
  • the positive resist composition of the present invention is applied onto the inorganic lower layer film formed in the lower layer film forming step and dried to form a resist film.
  • the resist film formed in the resist film forming step is irradiated with EUV to draw a desired pattern.
  • the development step the resist film exposed in the exposure step is brought into contact with a developer to develop the resist film, thereby forming a resist pattern on the lower layer film.
  • the resist film developed in the development step is brought into contact with a rinsing solution to rinse the developed resist film.
  • the lower layer film is etched using the resist pattern as a mask to form a pattern on the lower layer film.
  • the substrate is etched using the patterned lower layer film as a mask to form a pattern on the substrate.
  • the resist film obtained by the above-described resist pattern forming method has excellent etching resistance, particularly dry etching resistance. Note that the greater the proportion of carbon per unit volume of copolymer A and copolymer B contained in the positive resist composition, the more excellent the dry etching resistance of the resist film tends to be.
  • the laminate obtained by the method for forming a resist pattern described above includes a substrate and a resist film formed on the substrate.
  • copolymer A having a small surface free energy is on the surface side of the resist film. It can be unevenly distributed.
  • the resist film includes a lower layer provided on the substrate and an upper layer provided on the lower layer, the lower layer being composed of the above-mentioned copolymer B, and the upper layer being composed of the above-mentioned copolymer B. It is composed of union A.
  • the above-described laminate can be suitably used as a printed circuit board.
  • the proportion of monomer units in the copolymer was calculated using 1 H-NMR method. Specifically, the copolymer obtained in the preparation example was dissolved in chloroform-d, 99.8% (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) to a concentration of 10% by mass, and this solution was subjected to a nuclear magnetic resonance apparatus. (manufactured by JEOL Ltd., 400 mHz), and the proportion of monomer units in the copolymer was calculated from the measurement results.
  • ⁇ Number average molecular weight, weight average molecular weight and molecular weight distribution The number average molecular weight (Mn) and weight average molecular weight (Mw) of the copolymer obtained in the preparation example were measured using gel permeation chromatography, and the molecular weight distribution (Mw/Mn) was calculated. Specifically, using a gel permeation chromatograph (manufactured by Tosoh Corporation, HLC-8220) and using tetrahydrofuran as a developing solvent, the number average molecular weight (Mn) and weight average molecular weight (Mw) of the copolymer were measured using standard polystyrene. It was calculated as a converted value. Then, the molecular weight distribution (Mw/Mn) was calculated. In addition, it was confirmed that components having a weight average molecular weight of less than 1000 were substantially absent (less than 0.05% by mass) in the copolymer.
  • a spin coater manufactured by Mikasa Corporation, MS-A150
  • the EUV absorption coefficient was measured using the copolymer obtained in the preparation example. Specifically, first, a positive resist composition having a concentration of 2% by mass was prepared by dissolving the copolymer in isoamyl acetate as a solvent. Next, using a spin coater (manufactured by Mikasa Corporation, MS-A150), the positive resist composition was coated onto a silicon wafer having a diameter of 4 inches to a thickness of 50 nm. Then, the applied positive resist composition was heated on a hot plate at a temperature of 180° C. for 3 minutes to form a resist film for density measurement on the silicon wafer.
  • a spin coater manufactured by Mikasa Corporation, MS-A150
  • the film density of the resist film for density measurement was calculated by X-ray reflectivity (XRR method) using a fully automatic multi-purpose X-ray diffraction device (SmartLab, manufactured by Rigaku). Then, the EUV absorption coefficient at 92.5 eV was calculated from the actual value of the film density measured by the X-ray reflectance method (XRR method) and the constituent elements.
  • the EUV absorption coefficient in the examples of this application is based on the theoretical value on the National Institute of Standards and Technology (NIST) homepage (https://physics.nist.gov/PhysRefData/FFast/ht ml/form.html) using Calculated.
  • X-ray reflectance method In the X-ray reflectance method (XRR method), X-rays are incident on the sample surface at an extremely shallow angle, and the reflected X-ray intensity profile is measured in the direction of the incident angle versus the specular surface. This method determines the film thickness and film density of the sample by comparing the results with simulation results and optimizing the simulation parameters. By measuring the film thickness and film density using the X-ray reflectance method (XRR method), it is possible to accurately calculate the EUV absorption coefficient.
  • XRR method X-ray reflectance method
  • a spin coater manufactured by Mikasa Corporation, MS-A150
  • the irradiation amount of the electron beam was varied in steps of 4 ⁇ C/cm 2 within the range of 4 ⁇ C/cm 2 to 200 ⁇ C/cm 2 .
  • the thickness of the resist film in the drawn area was measured using an optical film thickness meter (Lambda Ace, manufactured by SCREEN Semiconductor Solutions Co., Ltd.), and the common logarithm of the total irradiation amount of the electron beam and the remaining thickness of the resist film after development were calculated.
  • the ⁇ value was determined using the following formula. The results are shown in Table 2.
  • E 0 is the quadratic function obtained by fitting the sensitivity curve to a quadratic function in the range of residual film rate from 0.20 to 0.80 (normal use of residual film rate and total irradiation dose). It is the logarithm of the total irradiation amount obtained when a residual film rate of 0 is substituted for the function (function with logarithm).
  • ⁇ Eth> A resist film was formed on a silicon wafer in the same manner as the evaluation method of " ⁇ value".
  • the initial thickness T 0 of the obtained resist film was measured using an optical film thickness meter (Lambda Ace, manufactured by SCREEN Semiconductor Solutions).
  • the total electron beam irradiation amount Eth ( ⁇ C/cm 2 ) when the residual film rate of the straight line (approximate line of the slope of the sensitivity curve) obtained when calculating the ⁇ value becomes 0 was determined.
  • the results are shown in Table 2. The smaller the value of Eth, the higher the sensitivity of the resist film and the higher the efficiency of forming a resist pattern.
  • Resist residue was evaluated using the positive resist compositions obtained in Examples and Comparative Examples. Specifically, first, a positive resist composition was applied onto a silicon wafer with a diameter of 4 inches using a spin coater (manufactured by Mikasa Corporation, MS-A150). Next, the applied positive resist composition was heated on a hot plate at a temperature of 180° C. for 3 minutes to form a resist film with a thickness of 40 nm on the silicon wafer (resist film forming step). Then, the resist film was exposed to light at an optimum exposure dose (Eop) using an electron beam drawing device (manufactured by Elionix Co., Ltd., ELS-S50) to draw a pattern (exposure step).
  • Eop exposure dose
  • ELS-S50 electron beam drawing device
  • a development process was performed for 1 minute at a temperature of 23° C. using isopropyl alcohol (IPA) as a developer (development step).
  • IPA isopropyl alcohol
  • a fluorinated solvent manufactured by 3M, Novec (registered trademark) 7100, methyl nonafluorobutyl ether, freezing point: -135°C, boiling point: 61°C
  • a resist pattern was formed by rinsing for seconds (developer removal step).
  • the resist pattern was observed using a scanning electron microscope (SEM) at a magnification of 100,000 times, and the amount of residue remaining in the resist pattern was evaluated according to the following criteria.
  • ⁇ Coverage rate> Coverage rates were evaluated using the positive resist compositions obtained in Examples and Comparative Examples.
  • the coverage rate is the ratio of the portion where copolymer A is unevenly distributed on the surface side of the resist film to the entire surface of the resist film.
  • the surface free energy of the positive resist compositions obtained in Examples and Comparative Examples was calculated in the same manner as the surface free energy of each copolymer described above. In other words, the surface free energy of the mixed system of copolymer A and copolymer B was calculated.
  • the coverage was calculated based on the following calculation formula (1).
  • SFE (AB) indicates the surface free energy of the mixed system of copolymer A and copolymer B. The results are shown in Table 2.
  • copolymer X1 was composed of ⁇ -chloroacrylate-1-phenyl-1-trifluoromethyl-2 , 5 mol% of 2,2-trifluoroethyl units, 45 mol% of ⁇ -chloroacrylic acid 2,2,3,3,4,4,4-heptafluorobutyl units, and 50 mol% of ⁇ -methylstyrene units. It was a polymer. Thereafter, the number average molecular weight, weight average molecular weight, molecular weight distribution, surface free energy, and EUV extinction coefficient of the obtained copolymer X1 were measured. The results are shown in Table 1.
  • the polymer recovered by filtration was dissolved in 10 g of THF, and the resulting solution was dropped into 100 g of a mixed solvent of THF and MeOH (THF:MeOH (mass ratio) 33:67) to form a white solid. was precipitated.
  • This coagulated material was collected again by filtration, the polymer collected by filtration was dissolved in 10 g of THF, and the resulting solution was dissolved in 100 g of a mixed solvent of THF and MeOH (THF:MeOH (mass ratio) 33:67). It was added dropwise to precipitate a white coagulate (copolymer X18).
  • copolymer X18 was composed of ⁇ -chloroacrylate-1-phenyl-1-trifluoromethyl-2 , 55 mol% of 2,2-trifluoroethyl units and 45 mol% of ⁇ -methylstyrene units. Thereafter, the number average molecular weight, weight average molecular weight, molecular weight distribution, surface free energy, and EUV extinction coefficient of the obtained copolymer X18 were measured. The results are shown in Table 1.
  • Example 1 ⁇ Preparation of positive resist composition> A positive resist composition was prepared using copolymer X1 and copolymer X18.
  • copolymer X1 corresponds to copolymer A
  • copolymer X18 corresponds to copolymer B.
  • copolymer X1 and copolymer X18 are dissolved in isoamyl acetate as a solvent so that the mass ratio of copolymer X1 and copolymer A 2% by mass positive resist composition was prepared.
  • the ⁇ value, Eth, residual film rate, resist residue, and coverage were measured or evaluated. The results are shown in Table 2.
  • Example 2 In the preparation of the positive resist composition, the various Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 3 In the preparation of the positive resist composition, the various Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 4 In the preparation of the positive resist composition, the same procedure as in Example 1 was carried out except that the mass ratio of copolymer X1 and copolymer X18 was changed to 30:70 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 5 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that copolymer X2 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X2 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 6 In the preparation of a positive resist composition, the same procedure as in Example 5 was carried out except that the mass ratio of copolymer X2 and copolymer X18 was changed to 10:90 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 7 In the preparation of a positive resist composition, the same procedure as in Example 5 was carried out except that the mass ratio of copolymer X2 and copolymer X18 was changed to 20:80 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 8 In the preparation of a positive resist composition, the same procedure as in Example 5 was carried out except that the mass ratio of copolymer X2 and copolymer X18 was changed to 30:70 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 9 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that copolymer X3 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X3 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 10 In the preparation of a positive resist composition, the same procedure as in Example 9 was carried out except that the mass ratio of copolymer X3 and copolymer X18 was changed to 10:90 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 11 In the preparation of a positive resist composition, the same procedure as in Example 9 was carried out except that the mass ratio of copolymer X3 and copolymer X18 was changed to 20:80 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 12 In the preparation of a positive resist composition, the same procedure as in Example 9 was carried out except that the mass ratio of copolymer X3 and copolymer X18 was changed to 30:70 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 13 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that copolymer X6 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X6 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 14 In the preparation of a positive resist composition, the same procedure as in Example 13 was carried out except that the mass ratio of copolymer X6 and copolymer X18 was changed to 10:90 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 15 In the preparation of a positive resist composition, the same procedure as in Example 13 was carried out except that the mass ratio of copolymer X6 and copolymer X18 was changed to 20:80 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 16 In the preparation of a positive resist composition, the various Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 17 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that copolymer X7 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X7 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 18 In the preparation of a positive resist composition, the same procedure as in Example 17 was carried out except that the mass ratio of copolymer X7 and copolymer X18 was changed to 10:90 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 19 In the preparation of a positive resist composition, the same procedure as in Example 17 was carried out except that the mass ratio of copolymer X7 and copolymer X18 was changed to 20:80 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 20 In the preparation of a positive resist composition, the same procedure as in Example 17 was carried out except that the mass ratio of copolymer X7 and copolymer X18 was changed to 30:70 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 21 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that copolymer X8 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X8 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 22 In the preparation of a positive resist composition, the same procedure as in Example 21 was carried out except that the mass ratio of copolymer X8 and copolymer X18 was changed to 10:90 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 23 In the preparation of a positive resist composition, the same procedure as in Example 21 was carried out except that the mass ratio of copolymer X8 and copolymer X18 was changed to 20:80 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 24 In the preparation of the positive resist composition, the same procedure as in Example 21 was carried out except that the mass ratio of copolymer X8 and copolymer X18 was changed to 30:70 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Example 25 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X11 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X11 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 26 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X12 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X12 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 27 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X4 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X4 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 28 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X13 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X13 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 29 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X14 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X14 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 30 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X15 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X15 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 31 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X16 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X16 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 32 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 3, except that copolymer X17 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X17 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Example 33 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 7, except that copolymer X19 was used instead of copolymer X18. The results are shown in Table 2. Note that copolymer X2 corresponds to copolymer A, and copolymer X19 corresponds to copolymer B.
  • Example 1 In preparing a positive resist composition, various operations, measurements, and evaluations were performed in the same manner as in Example 1, except that copolymer X5 was used instead of copolymer X1. The results are shown in Table 2. Note that copolymer X5 corresponds to copolymer A, and copolymer X18 corresponds to copolymer B.
  • Comparative example 2 In preparing a positive resist composition, the same procedure as in Comparative Example 1 was carried out except that the mass ratio of copolymer X5 and copolymer X18 was changed to 10:90 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Comparative example 3 In preparing a positive resist composition, the same procedure as in Comparative Example 1 was carried out except that the mass ratio of copolymer X5 and copolymer X18 was changed to 20:80 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Comparative example 4 In preparing a positive resist composition, the same procedure as in Comparative Example 1 was carried out except that the mass ratio of copolymer X5 and copolymer X18 was changed to 30:70 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Comparative Example 7 In preparing a positive resist composition, the same procedure as in Comparative Example 5 was carried out except that the mass ratio of copolymer X9 and copolymer Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Comparative example 8 In preparing a positive resist composition, the same procedure as in Comparative Example 5 was carried out except that the mass ratio of copolymer X9 and copolymer Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Comparative example 10 In preparing a positive resist composition, the same procedure as in Comparative Example 9 was carried out except that the mass ratio of copolymer X18 and copolymer Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Comparative Example 11 In preparing a positive resist composition, various preparations were made in the same manner as in Comparative Example 9, except that the mass ratio of copolymer X18 and copolymer X10 was changed to 80:20 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • Comparative example 12 In preparing a positive resist composition, the same procedure as in Comparative Example 9 was carried out except that the mass ratio of copolymer X18 and copolymer X10 was changed to 70:30 (copolymer A: copolymer B). Operations, measurements and evaluations were performed. The results are shown in Table 2.
  • SFE (A) indicates the surface free energy of copolymer A
  • SFE (B) indicates the surface free energy of copolymer B
  • IPA refers to isopropyl alcohol
  • a positive resist composition that can form a resist pattern with excellent clarity can be provided.

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Abstract

Le but de la présente invention est de fournir une composition de réserve de type positif qui peut former un motif de réserve d'une excellente netteté. La présente invention est une composition de réserve de type positif qui comprend un copolymère A, un copolymère B et un solvant, le copolymère A ayant une énergie libre de surface inférieure à celle du copolymère B, la différence entre les énergies libres de surface du copolymère B et du copolymère A étant d'au moins 3 mJ/m2, et le coefficient d'absorption des EUV du copolymère A étant d'au moins 55 000 cm-1.
PCT/JP2023/017090 2022-05-27 2023-05-01 Composition de réserve de type positif WO2023228691A1 (fr)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6029745A (ja) * 1983-07-28 1985-02-15 Fujitsu Ltd パタ−ン形成方法
JPS6064432A (ja) * 1983-09-19 1985-04-13 Fujitsu Ltd パタ−ン形成方法
JPH01217020A (ja) * 1988-02-26 1989-08-30 Tosoh Corp ポリアクリル酸誘導体
WO2018123667A1 (fr) * 2016-12-27 2018-07-05 日本ゼオン株式会社 Polymère, composition de réserve positive et procédé de formation de motif de réserve
JP2020052144A (ja) * 2018-09-25 2020-04-02 日本ゼオン株式会社 レジストパターン形成方法
JP2021134283A (ja) * 2020-02-27 2021-09-13 日本ゼオン株式会社 共重合体の製造方法およびポジ型レジスト組成物の製造方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6029745A (ja) * 1983-07-28 1985-02-15 Fujitsu Ltd パタ−ン形成方法
JPS6064432A (ja) * 1983-09-19 1985-04-13 Fujitsu Ltd パタ−ン形成方法
JPH01217020A (ja) * 1988-02-26 1989-08-30 Tosoh Corp ポリアクリル酸誘導体
WO2018123667A1 (fr) * 2016-12-27 2018-07-05 日本ゼオン株式会社 Polymère, composition de réserve positive et procédé de formation de motif de réserve
JP2020052144A (ja) * 2018-09-25 2020-04-02 日本ゼオン株式会社 レジストパターン形成方法
JP2021134283A (ja) * 2020-02-27 2021-09-13 日本ゼオン株式会社 共重合体の製造方法およびポジ型レジスト組成物の製造方法

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