Classifications

• • 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
• • 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
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1806—C6-(meth)acrylate, e.g. (cyclo)hexyl (meth)acrylate or phenyl (meth)acrylate
• • 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
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1809—C9-(meth)acrylate
• • 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
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
  • C08F220/1818—C13or longer chain (meth)acrylate, e.g. stearyl (meth)acrylate
• • 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
  • C08F220/26—Esters containing oxygen in addition to the carboxy oxygen
  • C08F220/28—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety
  • C08F220/283—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety and containing one or more carboxylic moiety in the chain, e.g. acetoacetoxyethyl(meth)acrylate
• • 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
  • C08F220/34—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate
  • C08F220/36—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate containing oxygen in addition to the carboxy oxygen, e.g. 2-N-morpholinoethyl (meth)acrylate or 2-isocyanatoethyl (meth)acrylate
  • C08F220/365—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate containing oxygen in addition to the carboxy oxygen, e.g. 2-N-morpholinoethyl (meth)acrylate or 2-isocyanatoethyl (meth)acrylate containing further carboxylic moieties
• • 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
• • 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
  • G03F7/0045—Photosensitive materials with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
• • 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
  • G03F7/0046—Photosensitive materials with perfluoro compounds, e.g. for dry lithography
• • 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
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
• • 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
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
  • G03F7/0388—Macromolecular compounds which are rendered insoluble or differentially wettable with ethylenic or acetylenic bands in the side chains of the photopolymer
• • 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
  • G03F7/0392—Macromolecular compounds which are photodegradable, e.g. positive electron resists the macromolecular compound being present in a chemically amplified positive photoresist composition
  • G03F7/0397—Macromolecular compounds which are photodegradable, e.g. positive electron resists the macromolecular compound being present in a chemically amplified positive photoresist composition the macromolecular compound having an alicyclic moiety in a side chain
• • 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
  • G03F7/20—Exposure; Apparatus therefor
• • 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
  • G03F7/20—Exposure; Apparatus therefor
  • G03F7/2002—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image
  • G03F7/2004—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light
• • 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
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
• • 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
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70008—Production of exposure light, i.e. light sources
  • G03F7/70025—Production of exposure light, i.e. light sources by lasers

Definitions

• the present invention relates to a radiation-sensitive resin composition and a pattern forming method.
• Photolithography technology using resist compositions is used to form fine circuits in semiconductor devices.
• an acid is generated by exposing a film of a resist composition to radiation through a mask pattern, and a reaction using the acid as a catalyst causes the resin to become alkaline or non-alkaline in the exposed and unexposed areas.
• a resist pattern is formed on a substrate by creating a difference in solubility in an organic developer.
• the above photolithography technology uses short-wavelength radiation such as ArF excimer laser, and liquid immersion exposure method (liquid immersion exposure method), in which the space between the lens of the exposure device and the resist film is filled with a liquid medium.
• short-wavelength radiation such as ArF excimer laser
• liquid immersion exposure method liquid immersion exposure method
• Lithography using shorter wavelength radiation such as electron beams, X-rays, and EUV (extreme ultraviolet) is also being considered as a next-generation technology.
• photoacid generators which are the main components of resist compositions
• perfluoroalkylsulfonic acids which can impart strong acids
• acid generators in which only the peripheral portion of sulfonic acid is fluorinated are being considered (see Japanese Patent Application Laid-Open No. 2013-114085).
• resist compositions include forming resist patterns with high aspect ratios in which the line width and hole diameter are 100 nm or less and the resist film thickness is 100 nm to 200 nm or more.
• CDU critical dimension uniformity
• pattern circularity which indicates the roundness of hole shape.
• Resist performance equivalent to or higher than that of conventional resists is required in terms of line width and LWR (Line Width Roughness) performance, which indicates variation in line width of a resist pattern.
• the present invention provides a radiation-sensitive resin composition and pattern that can form a resist film that can exhibit sensitivity, CDU performance, pattern circularity, and LWR performance at a sufficient level even when forming a resist pattern with a high aspect ratio.
• the purpose is to provide a forming method.
• a first onium salt compound represented by the following formula (1) A second onium salt compound represented by the following formula (2), A resin containing a structural unit having an acid-dissociable group;
• a radiation-sensitive resin composition comprising: a solvent;
• R 1 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 5 carbon atoms, or a group containing a divalent heteroatom-containing group between the carbon-carbon bonds of the hydrocarbon group.
• R 2 and R 3 are each independently a hydrogen atom, a fluorine atom, a monovalent hydrocarbon group, or a monovalent fluorinated hydrocarbon group.
• each of the plurality of R 2 and R 3 is the same or different.
• One of R f11 and R f12 is a fluorine atom, and the other is a hydrogen atom, a fluorine atom, or a monovalent fluorinated hydrocarbon group.
• m is an integer from 0 to 8.
• Z 1 + is a monovalent radiation-sensitive onium cation.
• R 4 is a monovalent organic group having 1 to 40 carbon atoms in which no fluorine atom or fluorinated hydrocarbon group is bonded to the atom adjacent to the sulfur atom.
• Z 2 + is a monovalent organic cation.
• the radiation-sensitive resin composition contains both a first onium salt compound as a radiation-sensitive acid generator and a second onium salt compound as a quencher (acid diffusion control agent), so it has a high aspect ratio. Even when forming a resist pattern, a resist film that exhibits excellent sensitivity, CDU performance, pattern circularity, and LWR performance can be formed. Although the reason for this is not bound by any theory, it is inferred as follows.
• the anion portion of the first onium salt compound has a relatively low molecular structure and is less affected by steric hindrance, so the diffusion length of the generated acid is relatively long. As a result, even if the resist film is thick, the generated acid can be sufficiently distributed without being unevenly distributed. Furthermore, since not all the carbon atoms in the anion moiety are fluorinated, the mobility of the carbon chain is improved, and in this respect as well, the homogeneity of the diffusion of the generated acid is improved.
• the second onium salt compound exhibits appropriate acid scavenging performance and can efficiently capture the acid generated from the first onium salt compound in the unexposed area.
• the organic group refers to a group containing at least one carbon atom.
• the present invention provides: a step of directly or indirectly applying the radiation-sensitive resin composition on a substrate to form a resist film; a step of exposing the resist film;
• the present invention relates to a pattern forming method including the step of developing the exposed resist film with a developer.
• the pattern forming method uses the radiation-sensitive resin composition that can form a resist film with excellent sensitivity, CDU performance, pattern circularity, and LWR performance, so a high-quality resist pattern can be efficiently formed. I can do it.
• the radiation-sensitive resin composition (hereinafter also simply referred to as "composition") according to the present embodiment comprises a first onium salt compound, a second onium salt compound, a resin containing a structural unit having an acid-dissociable group, and a solvent. including.
• the above composition may contain other optional components as long as they do not impair the effects of the present invention.
• the radiation-sensitive resin composition contains a first onium salt compound as a radiation-sensitive acid generator and a second onium salt compound as an acid diffusion control agent, thereby improving the resist film of the radiation-sensitive resin composition. It is possible to impart high levels of sensitivity, CDU performance, pattern circularity, and LWR performance to resist patterns.
• the first onium salt compound is represented by the above formula (1) and functions as a radiation-sensitive acid generator that generates acid upon irradiation with radiation.
• the composition may contain one or more types of first onium salt compounds.
• Examples of the monovalent hydrocarbon group having 1 to 5 carbon atoms in R 1 include a monovalent chain hydrocarbon group having 1 to 5 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 5 carbon atoms, etc. Can be mentioned.
• the monovalent chain hydrocarbon group having 1 to 5 carbon atoms is, for example, a monovalent linear or branched saturated hydrocarbon group having 1 to 5 carbon atoms, or a monovalent straight chain hydrocarbon group having 2 to 5 carbon atoms. Mention may be made of chain or branched unsaturated hydrocarbon groups. Examples of the monovalent linear or branched saturated hydrocarbon group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, and 2-methylpropyl group.
• Examples of the monovalent linear or branched unsaturated hydrocarbon group having 2 to 5 carbon atoms include vinyl group, allyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3 -butenyl group, 2-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 2-methyl-2-butenyl group, 1,2-dimethyl-2- Alkenyl groups having 2 to 5 carbon atoms such as propenyl group; ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-methyl
• the monovalent alicyclic hydrocarbon group having 3 to 5 carbon atoms includes a monocyclic saturated or unsaturated hydrocarbon group, or a polycyclic saturated hydrocarbon group.
• Examples of the monocyclic saturated hydrocarbon group include cyclopropyl group, 1-methylcyclopropyl group, cyclobutyl group, 1-methylcyclobutyl group, and cyclopentyl group.
• Examples of the monocyclic unsaturated hydrocarbon group include a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclobutadienyl group, and a cyclopentadienyl group.
• Examples of the polycyclic cycloalkyl group include a bicyclobutyl group and a spiropentyl group.
• the divalent hetero atom-containing group includes -CO-, -CS-, -O- , -S-, -SO 2 -, -NR''-, etc., and a combination of two or more of these can also be suitably used.
• R'' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 4 carbon atoms.
• R 1 has the above-mentioned substituent and a divalent heteroatom-containing group
• R 1 has 1 to 5 carbon atoms, including the carbon numbers of these groups.
• R 1 represents a substituted or unsubstituted monovalent saturated hydrocarbon group having 1 to 5 carbon atoms, or a divalent heteroatom-containing group between the carbon-carbon bonds of the saturated hydrocarbon group.
• R 1 is a group containing R 1 is a monovalent chain saturated hydrocarbon group having 1 to 5 carbon atoms, a monovalent alicyclic saturated hydrocarbon group having 3 to 5 carbon atoms, or a divalent group between the carbon-carbon bonds of these groups. More preferably, it is a group containing a heteroatom-containing group.
• the monovalent hydrocarbon groups represented by R 2 and R 3 include a group obtained by expanding the monovalent chain hydrocarbon group having 1 to 5 carbon atoms in R 1 to 20 carbon atoms, and Examples include a group obtained by extending a monovalent alicyclic hydrocarbon group having 3 to 5 carbon atoms to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a combination thereof.
• Examples of the monovalent chain hydrocarbon group having 6 to 20 carbon atoms include n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 2-methylpentyl group, 3-methylpentyl group.
• examples include the monovalent alicyclic hydrocarbon group having 6 to 20 carbon atoms.
• a monovalent monocyclic or polycyclic saturated hydrocarbon group or a monocyclic or polycyclic unsaturated hydrocarbon group can be mentioned.
• the monocyclic saturated hydrocarbon group a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group are preferable.
• the polycyclic cycloalkyl group is preferably a bridged alicyclic hydrocarbon group such as a norbornyl group, an adamantyl group, a tricyclodecyl group, or a tetracyclododecyl group.
• Examples of the monocyclic unsaturated hydrocarbon group include monocyclic cycloalkenyl groups such as cyclohexenyl group and cycloheptenyl.
• Examples of the polycyclic unsaturated hydrocarbon group include polycyclic cycloalkenyl groups such as norbornenyl group, tricyclodecenyl group, and tetracyclododecenyl group.
• a bridged alicyclic hydrocarbon group is a polycyclic alicyclic group in which two carbon atoms that are not adjacent to each other among the carbon atoms constituting the alicyclic ring are bonded by a linking group containing one or more carbon atoms.
• a cyclic hydrocarbon group is a polycyclic alicyclic group in which two carbon atoms that are not adjacent to each other among the carbon atoms constituting the alicyclic ring are bonded by a linking group containing one or more carbon atoms.
• Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, and anthryl group; benzyl group, phenethyl group, naphthylmethyl group, etc. Examples include aralkyl groups.
• the monovalent fluorinated hydrocarbon groups represented by R 2 , R 3 , R f11 and R f12 include monovalent fluorinated chain hydrocarbon groups having 1 to 20 carbon atoms, as well as monovalent fluorinated chain hydrocarbon groups having 3 to 20 carbon atoms. Examples include monovalent fluorinated alicyclic hydrocarbon groups.
• Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms include trifluoromethyl group, 2,2,2-trifluoroethyl group, pentafluoroethyl group, 2,2,3,3, 3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, heptafluoro n-propyl group, heptafluoro i-propyl group, nonafluoro n-butyl group, nonafluoro i-butyl group, Nonafluoro t-butyl group, 2,2,3,3,4,4,5,5-octafluoro n-pentyl group, tridecafluoro n-hexyl group, 5,5,5-trifluoro-1,1- Fluorinated alkyl groups such as diethylpentyl groups; Fluorinated alkenyl groups such as trifluoroethenyl group and penta
• Examples of the monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms include fluorocyclopentyl group, difluorocyclopentyl group, nonafluorocyclopentyl group, fluorocyclohexyl group, difluorocyclohexyl group, undecafluorocyclohexylmethyl group, Fluorinated cycloalkyl groups such as fluoronorbornyl group, fluoroadamantyl group, fluorobornyl group, fluoroisobornyl group, fluorotricyclodecyl group; Examples include fluorinated cycloalkenyl groups such as a fluorocyclopentenyl group and a nonafluorocyclohexenyl group.
• the above-mentioned fluorinated hydrocarbon group is preferably a monovalent fluorinated linear hydrocarbon group having 1 to 8 carbon atoms, more preferably a monovalent fluorinated linear hydrocarbon group having 1 to 5 carbon atoms.
• R 2 and R 3 are each independently a hydrogen atom or a monovalent hydrocarbon group, and it is more preferable that both R 2 and R 3 are hydrogen atoms.
• R f11 and R f12 are a fluorine atom, and the other is a hydrogen atom or a fluorine atom, and it is more preferable that both R f11 and R f12 are a fluorine atom.
• m is preferably an integer of 1 to 6, more preferably an integer of 1 to 5, and even more preferably an integer of 1 to 4.
• anion moiety of the first onium salt compound include, but are not limited to, structures of the following formulas (1-1-1) to (1-1-36).
• examples of the monovalent radiation-sensitive onium cation represented by Z 1 + include S, I, O, N, P, Cl, Br, F, As, Se, Sn,
• Examples include radiolytic onium cations containing elements such as Sb, Te, and Bi.
• radiolytic onium cations include sulfonium cations, tetrahydrothiophenium cations, iodonium cations, phosphonium cations, diazonium cations, and pyridinium cations. Among these, sulfonium cations or iodonium cations are preferred.
• the sulfonium cation or iodonium cation is preferably represented by the following formulas (X-1) to (X-6).
• R a1 , R a2 and R a3 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group, or an alkoxycarbonyl group.
• Oxy group or (cyclo)alkoxycarbonylalkoxy group substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 12 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, hydroxy group, a halogen atom, -OSO 2 -R P , -SO 2 -R Q or -S-R T , or a ring structure formed by combining two or more of these groups with each other.
• the ring structure may contain a heteroatom such as O or S between the carbon-carbon bonds forming the skeleton.
• R P , R Q and R T are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic group having 5 to 25 carbon atoms; It is a hydrocarbon group or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms.
• k1, k2 and k3 are each independently an integer of 0 to 5.
• R b1 is a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxy group or an alkoxyalkoxy group, or a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms; 8 acyl group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, a hydroxy group, or a halogen atom.
• n k is 0 or 1. When n k is 0, k4 is an integer from 0 to 4; when n k is 1, k4 is an integer from 0 to 7.
• R b1s When there is a plurality of R b1s , the plurality of R b1s may be the same or different, and the plurality of R b1s may represent a ring structure formed by being combined with each other.
• R b2 is a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms.
• L C is a single bond or a divalent linking group.
• k5 is an integer from 0 to 4.
• the plurality of R b2s may be the same or different, and the plurality of R b2s may represent a ring structure formed by being combined with each other.
• q is an integer from 0 to 3.
• the ring structure containing S + may contain a heteroatom such as O or S between the carbon-carbon bonds forming the skeleton.
• R c1 , R c2 and R c3 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms.
• R g1 is a substituted or unsubstituted linear or branched alkyl group or alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted acyl group having 2 to 8 carbon atoms. , a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, or a hydroxy group.
• n k2 is 0 or 1. When n k2 is 0, k10 is an integer from 0 to 4, and when n k2 is 1, k10 is an integer from 0 to 7.
• R g1s When there is a plurality of R g1s , the plurality of R g1s may be the same or different, and the plurality of R g1s may represent a ring structure formed by being combined with each other.
• R g2 and R g3 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group or an alkoxycarbonyloxy group, or a substituted or unsubstituted linear or branched alkyl group having 3 to 12 carbon atoms; 12 monocyclic or polycyclic cycloalkyl groups, substituted or unsubstituted aromatic hydrocarbon groups having 6 to 12 carbon atoms, hydroxy groups, halogen atoms, or rings formed by combining these groups with each other Represents a structure.
• k11 and k12 are each independently an integer of 0 to 4.
• R d1 and R d2 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group, or an alkoxycarbonyl group, a substituted or an unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a halogen atom, a halogenated alkyl group having 1 to 4 carbon atoms, a nitro group, or two or more of these groups are combined with each other.
• Represents a ring structure composed of k6 and k7 are each independently an integer of 0 to 5.
• each of the plurality of R d1 and R d2 may be the same or different.
• R e1 and R e2 are each independently a halogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted is an aromatic hydrocarbon group having 6 to 12 carbon atoms.
• k8 and k9 are each independently an integer of 0 to 4.
• radiation-sensitive onium cation examples include, but are not limited to, structures of the following formulas (1-2-1) to (1-2-54).
• the first onium salt compound can be obtained by appropriately combining the anion moiety and the radiation-sensitive onium cation.
• Specific examples include, but are not limited to, structures of the following formulas (1-1) to (1-36).
• the lower limit of the content of the first onium salt compound (or the total amount when multiple types of first onium salt compounds are included) is preferably 0.1 part by mass, more preferably 1 part by mass, per 100 parts by mass of the resin described below. It is preferably 5 parts by weight, more preferably 8 parts by weight.
• the upper limit of the content is preferably 60 parts by mass, more preferably 40 parts by mass, even more preferably 20 parts by mass, and particularly preferably 15 parts by mass.
• the content of the first onium salt compound is appropriately selected depending on the type of resin used, exposure conditions, required sensitivity, and the like. This makes it possible to exhibit excellent sensitivity, CDU performance, pattern circularity, and LWR performance during resist pattern formation.
• R 1 and Z 1 + have the same meanings as in formula (1) above.
• the bromo moiety of 3-bromo-2,2,3,3-tetrafluoropropan-1-ol is converted to a sulfonate with dithionite and an oxidizing agent, and the onium cation halide corresponding to the onium cation moiety (in the scheme, bromide) to proceed with salt exchange to obtain an onium salt.
• the desired first onium salt compound (1a) can be synthesized by reacting the hydroxy group of the onium salt with the carboxylic acid having the structure R1 .
• First onium salt compounds having other structures can be similarly synthesized by appropriately selecting starting materials and precursors corresponding to the anion moiety and the onium cation moiety.
• the second onium salt compound is represented by the above formula (2) and functions as an acid diffusion control agent. Furthermore, by including the second onium salt compound, the storage stability of the resulting radiation-sensitive resin composition is improved. Furthermore, the resolution of the resist pattern is further improved, and changes in line width of the resist pattern due to fluctuations in standing time from exposure to development can be suppressed, resulting in a radiation-sensitive resin composition with excellent process stability. It will be done.
• the composition may contain one or more types of second onium salt compounds.
• R 4 is a monovalent organic group having 1 to 40 carbon atoms. However, in R 4 , a fluorine atom and a fluorinated hydrocarbon group are not bonded to the atom (typically a carbon atom) adjacent to the sulfur atom in the above formula (2).
• the monovalent organic group having 1 to 40 carbon atoms represented by R 4 is, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a carbon-to-carbon group of this hydrocarbon group, or a monovalent organic group having 1 to 40 carbon atoms, or Examples include a group having a divalent heteroatom-containing group at the end, a group in which part or all of the hydrogen atoms of the above hydrocarbon group are substituted with a monovalent heteroatom-containing group, and a group combining these.
• the "organic group” is a group having at least one carbon atom.
• monovalent hydrocarbon group having 1 to 20 carbon atoms monovalent hydrocarbon groups represented by R 2 and R 3 in the above formula (1) can be suitably employed.
• heteroatom constituting the divalent or monovalent heteroatom-containing group examples include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a halogen atom, and the like.
• halogen atom examples include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
• the divalent heteroatom-containing group for R 1 above can be suitably employed.
• Examples of the monovalent heteroatom-containing group include a hydroxy group, a carboxy group, a sulfanyl group, a cyano group, a nitro group, and a halogen atom.
• R 4 is preferably a monovalent organic group having 3 to 40 carbon atoms and containing a cyclic structure. However, in this case as well, no fluorine atom or fluorinated hydrocarbon group is bonded to the atom (typically a carbon atom) adjacent to the sulfur atom in the above formula (2) in R 4 .
• the organic group is not particularly limited, and may be a group containing only a cyclic structure or a group containing a combination of a cyclic structure and a chain structure.
• the cyclic structure may be monocyclic, polycyclic, or a combination thereof. Further, the cyclic structure may be an alicyclic structure, an aromatic ring structure, a heterocyclic structure, or a combination thereof.
• the ring structures may be connected in a chain structure, or two or more ring structures may form a fused ring structure. These structures are preferably included as the minimum basic skeleton of the cyclic structure.
• the number of cyclic structures as the basic skeleton in the organic group may be 1 or 2 or more.
• the divalent heteroatom-containing group may be present between carbon atoms forming the skeleton of the cyclic structure or chain structure or at the end of the carbon chain, and if the hydrogen atom on the carbon atom of the cyclic structure or chain structure is may be substituted with a substituent.
• alicyclic structure a structure corresponding to a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms in R 2 and R 3 of the above formula (1) can be suitably employed.
• aromatic ring structure a structure corresponding to a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms in R 2 and R 3 of the above formula (1) can be suitably employed.
• chain structure a structure corresponding to a monovalent chain hydrocarbon group having 1 to 20 carbon atoms in R 2 and R 3 of the above formula (1) can be suitably employed.
• heterocyclic structures examples include aromatic heterocyclic structures and aliphatic heterocyclic structures.
• a 5-membered aromatic structure that has aromaticity by introducing a heteroatom is also included in the heterocyclic structure.
• the heteroatom examples include an oxygen atom, a nitrogen atom, a sulfur atom, and the like.
• aromatic heterocyclic structure examples include oxygen atom-containing aromatic heterocyclic structures such as furan and benzofuran; Nitrogen-containing aromatic heterocyclic structures such as pyrrole, imidazole, pyridine, pyrimidine, pyrazine, indole, quinoline, isoquinoline, acridine, phenazine, and carbazole; Sulfur atom-containing aromatic heterocyclic structures such as thiophene and benzothiophene; Examples include aromatic heterocyclic structures containing multiple heteroatoms such as thiazole, benzothiazole, thiazine, and oxazine.
• Examples of the aliphatic heterocyclic structures include oxygen atom-containing aliphatic heterocyclic structures such as oxirane, tetrahydrofuran, tetrahydropyran, dioxolane, and dioxane; Nitrogen-containing aliphatic heterocyclic structures such as aziridine, pyrrolidine, piperidine, piperazine; Sulfur atom-containing aliphatic heterocyclic structures such as thietane, thiolane, and thiane; Examples include aliphatic heterocyclic structures containing multiple heteroatoms such as morpholine, 1,2-oxathiolane, and 1,3-oxathiolane.
• the heterocyclic structure includes a lactone structure, a cyclic carbonate structure, a sultone structure, a cyclic acetal, or a combination thereof.
• the cyclic structure contained in R 4 is preferably a substituted or unsubstituted alicyclic polycyclic structure or heterocyclic polycyclic structure having 6 to 14 carbon atoms.
• anion moiety of the second onium salt compound include, but are not limited to, structures of the following formulas (2-1-1) to (2-1-27).
• organic cation of the second onium salt compound examples include, but are not limited to, known organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred. As the organic sulfonium cation and the organic iodonium cation, the structures listed as specific examples of the radiation-sensitive onium cation can be suitably employed.
• Examples of the second onium salt compound include a structure in which the above anion moiety and the above organic cation are arbitrarily combined.
• Specific examples of the second onium salt compound include, but are not limited to, onium salt compounds represented by the following formulas (2-1) to (2-30).
• the lower limit of the content of the second onium salt compound (or the total amount of the second onium salt compounds when multiple types of second onium salt compounds are included) is preferably 0.5 parts by mass per 100 parts by mass of the resin described below, and more preferably 1 part by mass. It is preferably 2 parts by mass, more preferably 3 parts by mass.
• the upper limit of the content is preferably 30 parts by mass, more preferably 20 parts by mass, even more preferably 15 parts by mass, and particularly preferably 10 parts by mass.
• the content of the second onium salt compound is appropriately selected depending on the type of resin used, exposure conditions, required sensitivity, and the like. This makes it possible to exhibit excellent CDU performance, pattern circularity, and LWR performance during resist pattern formation.
• the lower limit of the ratio a/b on a mass basis of the content a of the first onium salt compound to the content b of the second onium salt compound is preferably 0.01, more preferably 0.1, and still more preferably 1. Preferably, 1.5 is particularly preferable.
• the upper limit of the ratio a/b is preferably 20, more preferably 15, even more preferably 10, and particularly preferably 5.
• the resin is an aggregate of polymers containing a structural unit having an acid-dissociable group (hereinafter also referred to as “structural unit (I)”) (hereinafter, this resin is also referred to as “base resin”).
• structural unit (I) an acid-dissociable group
• base resin base resin
• the term "acid-dissociable group” refers to a group that substitutes for a hydrogen atom contained in a carboxy group, phenolic hydroxyl group, alcoholic hydroxyl group, sulfo group, etc., and is dissociated by the action of an acid.
• the radiation-sensitive resin composition has excellent pattern forming properties because the resin has the structural unit (I).
• the base resin preferably contains a structural unit (II) containing at least one type selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure, which will be described later. ) and (II) may also be included. Each structural unit will be explained below.
• Structural unit (I) is a structural unit containing an acid dissociable group.
• the structural unit (I) is not particularly limited as long as it contains an acid-dissociable group, and includes, for example, a structural unit having a tertiary alkyl ester moiety, and a structure in which the hydrogen atom of a phenolic hydroxyl group is substituted with a tertiary alkyl group. , a structural unit having an acetal bond, etc.
• structural unit represented by the following formula (3) (hereinafter referred to as "structural unit") (also referred to as "unit (I-1)) is preferred.
• R 17 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R 18 is a monovalent hydrocarbon group having 1 to 20 carbon atoms.
• R 19 and R 20 are each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or these groups represents a divalent alicyclic group having 3 to 20 carbon atoms formed by combining these with each other and the carbon atoms to which they are bonded.
• R 17 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.
• the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 18 above is, for example, a chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the like.
• the chain hydrocarbon group having 1 to 10 carbon atoms represented by R 18 to R 20 above is a linear or branched saturated hydrocarbon group having 1 to 10 carbon atoms, or a linear or branched hydrocarbon group having 1 to 10 carbon atoms. Examples include branched unsaturated hydrocarbon groups.
• the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R 18 to R 20 above is a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms in R 2 and R 3 of the above formula (1). Hydrogen groups can be suitably employed.
• the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R 18 above is the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms in R 2 and R 3 of the above formula (1). can be suitably employed.
• R 18 is preferably a linear or branched saturated hydrocarbon group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 20 carbon atoms.
• the divalent alicyclic group having 3 to 20 carbon atoms formed by combining R 19 and R 20 together with the carbon atom to which they are bonded is a monocyclic or polycyclic alicyclic hydrocarbon having the above number of carbon atoms. It is not particularly limited as long as it is a group obtained by removing two hydrogen atoms from the same carbon atoms constituting the carbon ring. Either a monocyclic hydrocarbon group or a polycyclic hydrocarbon group may be used, and the polycyclic hydrocarbon group may be a bridged alicyclic hydrocarbon group or a fused alicyclic hydrocarbon group, and a saturated hydrocarbon group may be used. Either a hydrogen group or an unsaturated hydrocarbon group may be used. Note that the condensed alicyclic hydrocarbon group refers to a polycyclic alicyclic hydrocarbon group in which a plurality of alicyclic rings share a side (a bond between two adjacent carbon atoms).
• the saturated hydrocarbon group is preferably a cyclopentanediyl group, cyclohexanediyl group, cycloheptanediyl group, cyclooctanediyl group, etc.
• the unsaturated hydrocarbon group is preferably a cyclopentenediyl group.
• cyclohexenediyl group, cycloheptendiyl group, cyclooctenediyl group, cyclodecenediyl group, etc. are preferable.
• the polycyclic alicyclic hydrocarbon group is preferably a bridged alicyclic saturated hydrocarbon group, such as a bicyclo[2.2.1]heptane-2,2-diyl group (norbornane-2,2-diyl group). ), bicyclo[2.2.2]octane-2,2-diyl group, tricyclo[3.3.1.1 3,7 ]decane-2,2-diyl group (adamantane-2,2-diyl group) , tricyclo[5.2.1.0 2,6 ]decane-8,8-diyl group and the like are preferred.
• a bridged alicyclic saturated hydrocarbon group such as a bicyclo[2.2.1]heptane-2,2-diyl group (norbornane-2,2-diyl group).
• bicyclo[2.2.2]octane-2,2-diyl group tricyclo[3.3.1.1 3,7 ]decane-2,2-diyl group (a
• R 18 is an alkyl group having 1 to 4 carbon atoms
• the alicyclic structure formed by combining R 19 and R 20 together with the carbon atoms to which they are bonded is a polycyclic or monocyclic cycloalkane.
• it is a structure.
• structural unit (I-1) for example, structural units represented by the following formulas (3-1) to (3-7) (hereinafter, "structural units (I-1-1) to (I-1- (also referred to as ⁇ 7)'').
• R 17 to R 20 have the same meanings as in the above formula (3).
• i and j are each independently an integer of 1 to 4.
• k and l are 0 or 1.
• R 18 is preferably a methyl group, ethyl group, isopropyl group or cyclopentyl group.
• R 19 and R 20 a methyl group or an ethyl group is preferable.
• the base resin may contain one type or a combination of two or more types of structural unit (I).
• the lower limit of the content ratio of the structural unit (I) (total content ratio when multiple types are included) is preferably 10 mol%, more preferably 20 mol%, and 30 mol% based on all structural units constituting the base resin. % is more preferable, and 35 mol% is particularly preferable. Further, the upper limit of the content ratio is preferably 80 mol%, more preferably 70 mol%, even more preferably 60 mol%, and particularly preferably 55 mol%.
• the structural unit (II) is a structural unit containing at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure.
• the base resin can adjust the solubility in the developer, and as a result, the radiation-sensitive resin composition improves lithography performance such as resolution. be able to. Furthermore, the adhesion between the resist pattern formed from the base resin and the substrate can be improved.
• Examples of the structural unit (II) include structural units represented by the following formulas (T-1) to (T-10).
• R L1 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R L2 to R L5 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a hydroxy group, a hydroxymethyl group, or a dimethylamino group.
• R L4 and R L5 may be a divalent alicyclic group having 3 to 8 carbon atoms that is formed together with the carbon atom to which they are bonded.
• L 2 is a single bond or a divalent linking group.
• X is an oxygen atom or a methylene group.
• k is an integer from 0 to 3.
• m is an integer from 1 to 3.
• R 19 and R 20 in the above formula (3) are each other.
• examples thereof include groups having 3 to 8 carbon atoms.
• One or more hydrogen atoms on this alicyclic group may be substituted with a hydroxy group.
• Examples of the divalent linking group represented by L 2 include a divalent linear or branched hydrocarbon group having 1 to 10 carbon atoms, and a divalent alicyclic carbonized group having 4 to 12 carbon atoms. Examples include a hydrogen group, or a group composed of one or more of these hydrocarbon groups and at least one group selected from -CO-, -O-, -NH-, and -S-.
• the structural unit (II) is preferably a structural unit containing a lactone structure, more preferably a structural unit containing a norbornane lactone structure, and even more preferably a structural unit derived from norbornane lactone-yl (meth)acrylate.
• the lower limit of the content of structural unit (II) is preferably 15 mol%, more preferably 20 mol%, and even more preferably 25 mol%, based on all structural units constituting the base resin. Further, the upper limit of the content ratio is preferably 80 mol%, more preferably 70 mol%, and even more preferably 65 mol%. By setting the content ratio of structural unit (II) within the above range, the radiation-sensitive resin composition can further improve lithography performance such as resolution and adhesion of the formed resist pattern to the substrate. .
• the base resin optionally has other structural units in addition to the above structural units (I) and (II).
• the above-mentioned other structural units include structural units (III) containing polar groups (excluding those corresponding to structural units (II)).
• the base resin can adjust the solubility in the developer, and as a result, improve the lithography performance such as resolution of the radiation-sensitive resin composition. I can do it.
• the polar group include a hydroxy group, a carboxy group, a cyano group, a nitro group, and a sulfonamide group. Among these, hydroxy group and carboxy group are preferred, and hydroxy group is more preferred.
• Examples of the structural unit (III) include structural units represented by the following formula.
• R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• the lower limit of the content of the structural unit (III) is preferably 5 mol%, and 8% by mole based on the total structural units constituting the base resin. More preferably mol %, and even more preferably 10 mol %. Further, the upper limit of the content ratio is preferably 40 mol%, more preferably 30 mol%, and even more preferably 25 mol%.
• the base resin may contain, as other structural units, a structural unit derived from hydroxystyrene or a structural unit having a phenolic hydroxyl group (hereinafter, both will be collectively referred to as "structural unit (IV)"). )” optionally.
• Structural unit (IV) contributes to improving etching resistance and improving the difference in developer solubility (dissolution contrast) between exposed areas and unexposed areas. In particular, it can be suitably applied to pattern formation using exposure to radiation with a wavelength of 50 nm or less, such as electron beams or EUV.
• the resin preferably has the structural unit (I) as well as the structural unit (IV).
• Structural units derived from hydroxystyrene are represented by, for example, the following formulas (4-1) to (4-2), and structural units having a phenolic hydroxyl group are, for example, represented by the following formulas (4-3) to (4-4). ) etc.
• R 41 is each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• Y is a halogen atom, a trifluoromethyl group, a cyano group, an alkyl group or alkoxy group having 1 to 6 carbon atoms, or an acyl group, acyloxy group, or alkoxycarbonyl group having 2 to 7 carbon atoms.
• t is an integer from 0 to 4.
• the phenolic hydroxyl group is protected by a protecting group such as an alkali-dissociable group (for example, an acyl group) during polymerization, and then the structure is obtained by deprotecting it by hydrolysis.
• a protecting group such as an alkali-dissociable group (for example, an acyl group) during polymerization, and then the structure is obtained by deprotecting it by hydrolysis.
• units (IV) are obtained.
• the lower limit of the content of the structural unit (IV) is preferably 10 mol%, more preferably 20 mol%, based on all structural units constituting the resin. Further, the upper limit of the content ratio is preferably 70 mol%, more preferably 60 mol%.
• the base resin may include a structural unit having an alicyclic structure represented by the following formula (6) as a structural unit other than the structural units listed above.
• R 1 ⁇ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R 2 ⁇ is a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms.
• the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R 2 ⁇ is one having 3 to 20 carbon atoms in R 2 and R 3 of the above formula (1).
• a valent alicyclic hydrocarbon group can be suitably employed.
• the lower limit of the content ratio of the above-mentioned structural unit having an alicyclic structure is preferably 2 mol%, and 5 mol% based on the total structural units constituting the base resin. % is more preferable, and 8 mol% is even more preferable.
• the upper limit of the content ratio is preferably 30 mol%, more preferably 20 mol%, and even more preferably 15 mol%.
• the base resin can be synthesized, for example, by polymerizing monomers providing each structural unit in an appropriate solvent using a radical polymerization initiator or the like.
• radical polymerization initiator examples include azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), and 2,2'-azobis(2-cyclopropylpropylene).
• azo radical initiators such as dimethyl 2,2'-azobisisobutyrate; benzoyl peroxide, t-butyl hydroperoxide, Examples include peroxide-based radical initiators such as cumene hydroperoxide.
• AIBN and dimethyl 2,2'-azobisisobutyrate are preferred, and AIBN is more preferred.
• Examples of the solvent used in the above polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane; Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, chlorobenzene; Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate; Ketones such as acetone, methyl ethyl
• the reaction temperature in the above polymerization is usually 40°C to 150°C, preferably 50°C to 120°C.
• the reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours.
• the molecular weight of the base resin is not particularly limited, but when the base resin is exposed to radiation with a wavelength exceeding 50 nm (ArF excimer laser, etc.), the weight average molecular weight (Mw) in terms of polystyrene determined by gel permeation chromatography (GPC) is The lower limit is preferably 4,000, more preferably 6,000, even more preferably 8,000, and particularly preferably 10,000.
• the upper limit of Mw is preferably 35,000, more preferably 25,000, even more preferably 20,000, and particularly preferably 15,000.
• the lower limit of Mw is preferably 2,000, more preferably 2,500, even more preferably 3,000, and even more preferably 3,500. Particularly preferred.
• the upper limit of Mw is preferably 20,000, more preferably 15,000, even more preferably 10,000, and particularly preferably 7,000.
• the ratio (Mw/Mn) of Mw to the polystyrene equivalent number average molecular weight (Mn) determined by GPC of the base resin is usually 1 or more and 5 or less, preferably 1 or more and 3 or less, and more preferably 1 or more and 2 or less.
• the Mw and Mn of the resin in this specification are values measured using gel permeation chromatography (GPC) under the following conditions.
• the content ratio of the base resin is preferably 60% by mass or more, more preferably 65% by mass or more, and even more preferably 70% by mass or more, based on the total solid content of the radiation-sensitive resin composition.
• the radiation-sensitive resin composition of the present embodiment may contain a resin having a higher mass content of fluorine atoms than the base resin (hereinafter also referred to as "high fluorine content resin") as another resin. good.
• the radiation-sensitive resin composition contains a resin with a high fluorine content, it can be unevenly distributed in the surface layer of the resist film with respect to the base resin, and as a result, the repellency of the surface of the resist film during immersion exposure is reduced. It is possible to improve the aqueous property, modify the surface of the resist film during EUV exposure, and control the distribution of composition within the film.
• the high fluorine content resin preferably has a structural unit represented by the following formula (5) (hereinafter also referred to as "structural unit (V)"), and if necessary, the structural unit in the base resin. It may have (I) or structural unit (III).
• R 13 is a hydrogen atom, a methyl group, or a trifluoromethyl group.
• G L is a single bond, an alkanediyl group having 1 to 5 carbon atoms, an oxygen atom, a sulfur atom, -COO-, -SO 2 ONH-, -CONH-, -OCONH-, or a combination thereof.
• R 14 is a monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms.
• R 13 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.
• the above G L is preferably a single bond and -COO-, and more preferably -COO-.
• the monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms represented by R 14 above some or all of the hydrogen atoms possessed by the linear or branched alkyl group having 1 to 20 carbon atoms are fluorine. Examples include those substituted by atoms.
• the monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R 14 above is a part of the hydrogen atom possessed by a monocyclic or polycyclic hydrocarbon group having 3 to 20 carbon atoms, or Examples include those in which all fluorine atoms are substituted.
• R 14 is preferably a fluorinated chain hydrocarbon group, more preferably a fluorinated alkyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, More preferred are 1,1,1,3,3,3-hexafluoropropyl group and 5,5,5-trifluoro-1,1-diethylpentyl group.
• the lower limit of the content of the structural unit (V) is preferably 50 mol% and 60 mol% based on the total structural units constituting the high fluorine content resin. % is more preferable, and 70 mol% is even more preferable. Further, the upper limit of the content ratio is preferably 95 mol%, more preferably 90 mol%, and even more preferably 85 mol%.
• the high fluorine content resin includes a fluorine atom-containing structural unit (hereinafter also referred to as structural unit (VI)) represented by the following formula (f-2) together with or in place of the structural unit (V). ).
• structural unit (VI) fluorine atom-containing structural unit represented by the following formula (f-2) together with or in place of the structural unit (V).
• the high fluorine content resin improves solubility in an alkaline developer and can suppress the occurrence of development defects.
• Structural unit (VI) may have (x) an alkali-soluble group, or (y) a group that dissociates under the action of an alkali to increase its solubility in an alkaline developer (hereinafter also referred to simply as an "alkali-dissociable group"). ).
• R C is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• R D is a single bond, a (s+1)-valent hydrocarbon group having 1 to 20 carbon atoms, an oxygen atom, a sulfur atom, -NR dd -, a carbonyl group, -COO-, This is a structure in which -OCO- or -CONH- is bonded, or a structure in which some of the hydrogen atoms of this hydrocarbon group are replaced by an organic group having a heteroatom.
• R dd is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. s is an integer from 1 to 3.
• R F is a hydrogen atom
• a 1 is an oxygen atom, -COO-* or -SO 2 O-*. * indicates a site that binds to RF .
• W 1 is a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or a divalent fluorinated hydrocarbon group.
• a 1 is an oxygen atom
• W 1 is a fluorinated hydrocarbon group having a fluorine atom or a fluoroalkyl group on the carbon atom to which A 1 is bonded.
• R E is a single bond or a divalent organic group having 1 to 20 carbon atoms.
• the plurality of R E , W 1 , A 1 and R F may be the same or different.
• the structural unit (VI) has (x) an alkali-soluble group, the affinity for an alkaline developer can be increased and development defects can be suppressed.
• the structural unit (VI) having an alkali-soluble group when A 1 is an oxygen atom and W 1 is a 1,1,1,3,3,3-hexafluoro-2,2-methanediyl group is particularly preferred.
• R F is a monovalent organic group having 1 to 30 carbon atoms
• a 1 is an oxygen atom, -NR aa -, -COO-*, -OCO-* or -SO 2 O-*.
• R aa is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates a site that binds to RF .
• W 1 is a single bond or a divalent fluorinated hydrocarbon group having 1 to 20 carbon atoms.
• R E is a single bond or a divalent organic group having 1 to 20 carbon atoms.
• W 1 or R F has a fluorine atom on the carbon atom bonded to A 1 or on the carbon atom adjacent thereto.
• a 1 is an oxygen atom
• W 1 and R E are single bonds
• R D is a structure in which a carbonyl group is bonded to the R E side end of a hydrocarbon group having 1 to 20 carbon atoms
• R F is an organic group containing a fluorine atom.
• s is 2 or 3
• the plurality of R E , W 1 , A 1 and R F may be the same or different.
• the structural unit (VI) having an alkali-dissociable group is particularly preferably one in which A 1 is -COO-* and R F or W 1 or both have a fluorine atom.
• R C a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable, from the viewpoint of copolymerizability of the monomer providing the structural unit (VI).
• R E is a divalent organic group
• a group having a lactone structure is preferable, a group having a polycyclic lactone structure is more preferable, and a group having a norbornane lactone structure is even more preferable.
• the lower limit of the content of the structural unit (VI) is preferably 40 mol% and 50 mol% based on the total structural units constituting the high fluorine content resin. % is more preferable, and 55 mol% is even more preferable. Further, the upper limit of the content ratio is preferably 90 mol%, more preferably 80 mol%, and even more preferably 75 mol%.
• the high fluorine content resin may include a structural unit having an alicyclic structure represented by the above formula (6) as a structural unit other than the structural units listed above.
• the lower limit of the content ratio of the above-mentioned structural unit having the alicyclic structure is 10 mol with respect to all the structural units constituting the high fluorine content resin. %, more preferably 20 mol%, even more preferably 30 mol%. Moreover, the upper limit of the content ratio is preferably 60 mol%, more preferably 50 mol%, and even more preferably 45 mol%.
• the lower limit of Mw of the high fluorine content resin is preferably 4,000, more preferably 6,000, even more preferably 8,000, and particularly preferably 10,000. Further, the upper limit of Mw is preferably 35,000, more preferably 25,000, even more preferably 20,000, and particularly preferably 15,000.
• the lower limit of Mw/Mn of the high fluorine content resin is usually 1, and 1.1 is more preferable. Further, the upper limit of Mw/Mn is usually 5, preferably 3, and more preferably 2.
• the content of the high fluorine content resin is preferably 0.1 part by mass or more, and 0.5 parts by mass based on 100 parts by mass of the base resin.
• the amount is more preferably at least 1 part by mass, even more preferably at least 1 part by mass, and particularly preferably at least 1.5 parts by mass. Further, it is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 8 parts by mass or less, and particularly preferably 5 parts by mass or less.
• the high fluorine content resin can be more effectively unevenly distributed on the surface layer of the resist film, and as a result, the surface of the resist film during immersion exposure water repellency can be further improved. Furthermore, it is also possible to modify the surface of the resist film during EUV exposure and to control the distribution of composition within the film.
• the radiation-sensitive resin composition may contain one or more high fluorine content resins.
• the high fluorine content resin can be synthesized by a method similar to the method for synthesizing the base resin described above.
• the radiation-sensitive resin composition according to this embodiment contains a solvent.
• the solvent is not particularly limited as long as it can dissolve or disperse at least the first onium salt compound, the second onium salt compound, the resin, and optionally contained high fluorine content resin.
• solvent examples include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.
• Alcohol-based solvents include: Carbon such as iso-propanol, 4-methyl-2-pentanol, 3-methoxybutanol, n-hexanol, 2-ethylhexanol, furfuryl alcohol, cyclohexanol, 3,3,5-trimethylcyclohexanol, diacetone alcohol, etc.
• Alcohol-based solvent examples include polyhydric alcohol partially ether-based solvents in which a portion of the hydroxyl groups of the above-mentioned polyhydric alcohol-based solvents are etherified.
• ether solvents include: Dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether; Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran; Aromatic ring-containing ether solvents such as diphenyl ether and anisole (methyl phenyl ether); Examples include polyhydric alcohol ether solvents in which the hydroxyl groups of the above polyhydric alcohol solvents are etherified.
• ketone solvents include chain ketone solvents such as acetone, butanone, and methyl-iso-butyl ketone: Cyclic ketone solvents such as cyclopentanone, cyclohexanone, methylcyclohexanone: Examples include 2,4-pentanedione, acetonyl acetone, and acetophenone.
• amide solvents include cyclic amide solvents such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone;
• chain amide solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.
• ester solvents include: Monocarboxylic acid ester solvent such as n-butyl acetate; Polyhydric alcohol partial ether acetate solvents such as diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate; Lactone solvents such as ⁇ -butyrolactone and valerolactone; Carbonate solvents such as diethyl carbonate, ethylene carbonate, propylene carbonate; Polyhydric carboxylic acid diester solvents such as propylene glycol diacetate, methoxytriglycol acetate, diethyl oxalate, ethyl acetoacetate, and diethyl phthalate can be mentioned.
• Monocarboxylic acid ester solvent such as n-butyl acetate
• Polyhydric alcohol partial ether acetate solvents such as diethylene glycol mono-n-butyl ether acetate, propylene
• hydrocarbon solvents examples include aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane; Examples include aromatic hydrocarbon solvents such as benzene, toluene, di-iso-propylbenzene, and n-amylnaphthalene.
• alcohol solvents preferred; alcoholic ester solvents, polyhydric alcohol partial ether acetate solvents, lactone solvents, monocarboxylic acid ester solvents, and polyhydric alcohol partial ethers.
• System solvents are more preferred, and propylene glycol monomethyl ether acetate, ⁇ -butyrolactone, ethyl lactate, and propylene glycol monomethyl ether are even more preferred.
• the radiation-sensitive resin composition may contain one or more solvents.
• the above-mentioned radiation-sensitive resin composition may contain other optional components in addition to the above-mentioned components.
• the above-mentioned other optional components include a crosslinking agent, a uneven distribution promoter, a surfactant, an alicyclic skeleton-containing compound, a sensitizer, and the like. These other optional components may be used alone or in combination of two or more.
• the radiation-sensitive resin composition is prepared by mixing, for example, a first onium salt compound, a second onium salt compound, a resin, optional components such as a high fluorine content resin, and a solvent in a predetermined ratio. It can be prepared by After mixing, the radiation-sensitive resin composition is preferably filtered, for example, through a filter having a pore size of about 0.05 ⁇ m to 0.40 ⁇ m.
• the solid content concentration of the radiation-sensitive resin composition is usually 0.1% to 50% by weight, preferably 0.5% to 30% by weight, and more preferably 1% to 20% by weight.
• a pattern forming method includes: Step (1) of forming a resist film by directly or indirectly applying the radiation-sensitive resin composition on the substrate (hereinafter also referred to as “resist film forming step”); Step (2) of exposing the resist film (hereinafter also referred to as “exposure step”); The method includes a step (3) of developing the exposed resist film (hereinafter also referred to as “developing step”).
• the radiation-sensitive resin composition capable of forming a resist film with excellent sensitivity, CDU performance, pattern circularity, and LWR performance is used, so a high-quality resist pattern can be formed. be able to.
• Each step will be explained below.
• a resist film is formed using the radiation-sensitive resin composition.
• the substrate on which this resist film is formed include conventionally known substrates such as silicon wafers, silicon dioxide, and wafers coated with aluminum.
• an organic or inorganic antireflection film disclosed in Japanese Patent Publication No. 6-12452, Japanese Patent Application Laid-Open No. 59-93448, etc. may be formed on the substrate.
• the coating method include spin coating, casting coating, and roll coating.
• pre-baking (PB) may be performed, if necessary, in order to volatilize the solvent in the coating film.
• the PB temperature is usually 60°C to 150°C, preferably 80°C to 140°C.
• the PB time is usually 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds.
• the lower limit of the thickness of the resist film to be formed is preferably 10 nm, more preferably 15 nm, and even more preferably 20 nm.
• the upper limit of the film thickness is preferably 500 nm, more preferably 400 nm, and even more preferably 300 nm.
• the lower limit of the film thickness may be 100 nm, 150 nm, or 200 nm. good.
• an immersion protective film insoluble in the immersion liquid may be provided.
• the protective film for liquid immersion includes a solvent-removable protective film that is removed with a solvent before the development process (for example, see Japanese Patent Application Laid-open No. 2006-227632), a developer-removable protective film that is removed at the same time as development in the development process (for example, any of WO2005-069076 and WO2006-035790 may be used. However, from the viewpoint of throughput, it is preferable to use a developer-removable protective film for immersion.
• the exposure step is performed with radiation having a wavelength of 50 nm or less
• the resist film formed in the resist film forming step (step (1) above) is applied to the resist film through a photomask (in some cases, through an immersion liquid such as water). , irradiate and expose with radiation.
• the radiation used for exposure includes electromagnetic waves such as visible light, ultraviolet rays, far ultraviolet rays, EUV (extreme ultraviolet), X-rays, and gamma rays; electron beams, alpha rays, etc., depending on the line width of the target pattern. Examples include charged particle beams.
• far ultraviolet rays, electron beams, and EUV are preferable, and ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), electron beam, and EUV are more preferable, and wavelength 50 nm is positioned as a next-generation exposure technology.
• the following electron beam and EUV are more preferable.
• the immersion liquid used When exposure is performed by immersion exposure, examples of the immersion liquid used include water, fluorine-based inert liquid, and the like.
• the immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has as small a temperature coefficient of refractive index as possible to minimize distortion of the optical image projected onto the film.
• excimer laser light wavelength: 193 nm
• water is preferably used from the viewpoint of ease of acquisition and handling, in addition to the above-mentioned viewpoints.
• additives that reduce the surface tension of water and increase surfactant power may be added in small proportions. This additive is preferably one that does not dissolve the resist film on the wafer and has a negligible effect on the optical coating on the lower surface of the lens.
• the water used is preferably distilled water.
• PEB post-exposure baking
• This PEB causes a difference in solubility in the developer between the exposed area and the unexposed area.
• the PEB temperature is usually 50°C to 180°C, preferably 80°C to 130°C.
• the PEB time is usually 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds.
• step (3) the resist film exposed in the exposure step (step (2)) is developed. Thereby, a predetermined resist pattern can be formed. After development, it is common to wash with a rinsing liquid such as water or alcohol and dry.
• a rinsing liquid such as water or alcohol
• the developer used for the above development includes, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di- n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene
• TMAH tetramethylammonium hydroxide
• Examples include an alkaline aqueous solution in which at least one alkaline compound such as , 1,5-diazabicyclo-[4.3.0]-5-nonene is dissolved.
• a TMAH aqueous solution is preferred, and a 2.38% by mass TMAH aqueous solution is more preferred.
• organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, and alcohol solvents, or solvents containing organic solvents can be used.
• organic solvent include one or more of the solvents listed as solvents for the radiation-sensitive resin compositions described above.
• ether solvents, ester solvents, and ketone solvents are preferred.
• ether solvent a glycol ether solvent is preferred, and ethylene glycol monomethyl ether and propylene glycol monomethyl ether are more preferred.
• ester solvent an acetate ester solvent is preferred, and n-butyl acetate and amyl acetate are more preferred.
• the content of the organic solvent in the developer is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more.
• components other than the organic solvent in the developer include water, silicone oil, and the like.
• the developer may be either an alkaline developer or an organic solvent developer. It can be selected as appropriate depending on whether the desired positive pattern or negative pattern is desired.
• Development methods include, for example, a method in which the substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and then developed by standing still for a certain period of time (paddle method). method), a method in which the developer is sprayed onto the substrate surface (spray method), and a method in which the developer is continuously discharged while scanning the developer discharge nozzle at a constant speed onto a rotating substrate (dynamic dispensing method). etc. can be given.
• Mw and Mn of the polymer were measured under the conditions described above. Further, the degree of dispersion (Mw/Mn) was calculated from the measurement results of Mw and Mn.
• 13 C-NMR analysis 13 C-NMR analysis of the polymer was performed using a nuclear magnetic resonance apparatus (JNM-Delta400, manufactured by JEOL Ltd.).
• the polymerization reaction was carried out for 6 hours with the start of the dropwise addition as the start time of the polymerization reaction. After the polymerization reaction was completed, the polymerization solution was cooled to 30° C. or lower with water. The cooled polymerization solution was poured into methanol (2,000 parts by mass), and the precipitated white powder was filtered off. The filtered white powder was washed twice with methanol, filtered, and dried at 50° C. for 24 hours to obtain white powdery resin (A-1) (yield: 88%). Resin (A-1) had an Mw of 12,000 and an Mw/Mn of 1.51.
• the content ratio of each structural unit derived from (M-1), (M-2), (M-5), (M-10) and (M-14) is as follows: They were 41.0 mol%, 7.8 mol%, 21.2 mol%, 20.3 mol%, and 9.7 mol%, respectively.
• the polymerization solution was cooled to 30° C. or lower with water.
• the cooled polymerization solution was poured into hexane (2,000 parts by mass), and the precipitated white powder was filtered out.
• the filtered white powder was washed twice with hexane, filtered, and dissolved in 1-methoxy-2-propanol (300 parts by mass).
• methanol (500 parts by mass), triethylamine (50 parts by mass) and ultrapure water (10 parts by mass) were added, and a hydrolysis reaction was carried out at 70° C. for 6 hours with stirring.
• the polymerization solution was cooled to 30° C. or lower with water. After replacing the solvent with acetonitrile (400 parts by mass), adding hexane (100 parts by mass), stirring, and collecting the acetonitrile layer were repeated three times. By replacing the solvent with propylene glycol monomethyl ether acetate, a solution of high fluorine content resin (F-1) was obtained (yield: 86%).
• the Mw of the high fluorine content resin (F-1) was 12,200, and the Mw/Mn was 1.89.
• the content of each structural unit derived from (M-1), (M-15), and (M-20) was 20.2 mol% and 9.3 mol%, respectively. , and 70.5 mol%.
• a mixture of acetonitrile:water (1:1 (mass ratio)) was added to 20.0 mmol of 4-bromo-3,3,4,4-tetrafluorobutan-1-ol in a reaction vessel to make a 1M solution.
• 40.0 mmol of sodium dithionite and 60.0 mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 4 hours.
• a mixture of acetonitrile and water (3:1 (mass ratio)) was added to make a 0.5M solution.
• 60.0 mmol of hydrogen peroxide solution and 2.00 mmol of sodium tungstate were added, and the mixture was heated and stirred at 50° C.
• a sulfonic acid sodium salt compound was obtained by extraction with acetonitrile and distilling off the solvent. 20.0 mmol of triphenylsulfonium bromide was added to the sulfonic acid sodium salt compound, and a 0.5M solution was prepared by adding a mixture of water and dichloromethane (1:3 (mass ratio)). After stirring vigorously at room temperature for 3 hours, dichloromethane was added for extraction and the organic layer was separated. After drying the obtained organic layer with sodium sulfate, the solvent was distilled off and the onium salt was purified by column chromatography to obtain an onium salt in good yield.
• E-1 Propylene glycol monomethyl ether acetate
• E-2 Propylene glycol monomethyl ether
• E-3 ⁇ -butyrolactone
• E-4 Ethyl lactate
• Example 1 [Preparation of positive radiation-sensitive resin composition for ArF immersion exposure] [Example 1] [A] 100 parts by mass of (A-1) as a resin, [B] 10.0 parts by mass of (B-1) as a first onium salt compound, [D] (D-1 as a second onium salt compound) ) 5.0 parts by mass, [F] 3.0 parts by mass (solid content) of (F-1) as a high fluorine content resin, and [E] (E-1)/(E-2) as a solvent.
• a radiation-sensitive resin composition (J-1) was prepared by mixing 3,230 parts by mass of a mixed solvent of /(E-3) and filtering the mixture through a membrane filter with a pore size of 0.2 ⁇ m.
• this resist film was exposed using an ArF excimer laser immersion exposure system (ASML's "TWINSCAN XT-1900i" with an optical Exposure was performed through a mask pattern of 80 nm holes and 150 nm pitch contact holes under the following conditions.
• PEB post exposure bake
• the above resist film is developed in alkali using a 2.38 mass% TMAH aqueous solution as an alkaline developer, and after development, it is washed with water and further dried to form a positive resist pattern (80 nm holes, 150 nm pitch contacts). A hole pattern) was formed.
• the optimum exposure dose is defined as the exposure dose for forming 80 nm holes and 150 nm pitch contact holes, and this optimum exposure dose is used as the sensitivity (mJ /cm 2 ). Sensitivity was evaluated as "good” when it was 30 mJ/cm 2 or less, and “poor” when it exceeded 30 mJ/cm 2 .
• CDU performance Contact holes with a diameter of 80 nm and a pitch of 150 nm were formed by irradiation with the optimum exposure amount determined in the above sensitivity evaluation. The formed resist pattern was observed from above the pattern using the above scanning electron microscope. The variation in the diameter of the contact hole was measured at a total of 500 points, a 3 sigma value was determined from the distribution of the measured values, and this 3 sigma value was defined as CDU (nm). The smaller the CDU value, the smaller the hole roughness and the better the hole roughness. The CDU performance was evaluated as "good” if it was less than 5.0 nm, and “poor” if it was 5.0 nm or more.
• the radiation-sensitive resin compositions of the Examples had good sensitivity, CDU performance, and pattern circularity when used in ArF immersion exposure, whereas the comparative examples showed good sensitivity, CDU performance, and pattern circularity. In this case, each characteristic was inferior to that in the example. Therefore, when the radiation-sensitive resin composition of the example is used for ArF immersion exposure, a resist pattern with high sensitivity and good CDU performance and pattern circularity can be formed.
• Example 42 [A] 100 parts by mass of (A-1) as a resin, [B] 12.0 parts by mass of (B-1) as a first onium salt compound, [D] (D-1 as a second onium salt compound) ) 5.0 parts by mass and 3,230 parts by mass of a mixed solvent of (E-1)/(E-2)/(E-3) as [E] solvent, and filtered with a membrane filter with a pore size of 0.2 ⁇ m.
• a radiation-sensitive resin composition (J-42) was prepared by filtration.
• a resist film having an average thickness of 250 nm was formed by cooling at 23° C. for 30 seconds.
• a resist pattern of holes and contact holes with a pitch of 180 nm was formed.
• PEB post exposure bake
• the above resist film is developed with alkali using a 2.38 mass% TMAH aqueous solution as an alkaline developer, and after development, it is washed with water and further dried to form a positive resist pattern (100 nm hole, 180 nm pitch contact). A hole resist pattern) was formed.
• the exposure amount that forms a contact hole pattern with 100 nm holes and 180 nm pitch is set as the optimum exposure amount, and this optimum exposure amount is used as the sensitivity ( mJ/cm 2 ). Sensitivity was evaluated as "good” when it was 40 mJ/cm 2 or less, and “poor” when it exceeded 40 mJ/cm 2 .
• CDU performance Contact holes with a diameter of 100 nm and a pitch of 180 nm were formed by irradiation with the optimum exposure amount determined in the above sensitivity evaluation. The formed resist pattern was observed from above the pattern using the above scanning electron microscope. The variation in contact holes was measured at a total of 500 points, a 3 sigma value was determined from the distribution of the measured values, and this 3 sigma value was defined as CDU (nm). The smaller the CDU value, the smaller the hole roughness and the better the hole roughness. The CDU performance was evaluated as "good” if it was less than 5.0 nm, and “poor” if it was 5.0 nm or more.
• the radiation-sensitive resin compositions of the Examples had good sensitivity, CDU performance, and pattern circularity when used for ArF-Dry exposure, whereas the comparative examples showed good sensitivity, CDU performance, and pattern circularity. , each characteristic was inferior to that of the example. Therefore, when the radiation-sensitive resin composition of the example is used for ArF-Dry exposure, a resist pattern with high sensitivity and good CDU performance and pattern circularity can be formed.
• Example 52 [Preparation of positive radiation-sensitive resin composition for extreme ultraviolet (EUV) exposure] [Example 52] [A] 100 parts by mass of (A-12) as a resin, [B] 15.0 parts by mass of (B-1) as a first onium salt compound, [D] (D-1 as a second onium salt compound) ) 5.0 parts by mass, [F] 3.0 parts by mass (solid content) of (F-5) as a high fluorine content resin, and [E] (E-1)/(E-4) as a solvent.
• a radiation-sensitive resin composition (J-52) was prepared by mixing 6,110 parts by mass of the mixed solvent and filtering through a membrane filter with a pore size of 0.2 ⁇ m.
• the exposure amount that forms a 32 nm line-and-space pattern is defined as the optimum exposure amount, and this optimum exposure amount is defined as the sensitivity (mJ/cm 2 ). did. Sensitivity was evaluated as "good” when it was 20 mJ/cm 2 or less, and “poor” when it exceeded 20 mJ/cm 2 .
• LWR performance A resist pattern was formed by adjusting the mask size so as to form a 32 nm line-and-space pattern by applying the optimum exposure amount determined in the above sensitivity evaluation. The formed resist pattern was observed from above the pattern using the above scanning electron microscope. The variation in line width was measured at a total of 500 points, a 3 sigma value was determined from the distribution of the measured values, and this 3 sigma value was defined as LWR (nm). The smaller the LWR value, the less wobbling the line is and the better it is. The LWR performance was evaluated as "good” if it was 4.0 nm or less, and “poor” if it exceeded 4.0 nm.
• Example 64 [A] 100 parts by mass of (A-1) as a resin, [B] 12.0 parts by mass of (B-1) as a first onium salt compound, [D] (D-5 as a second onium salt compound) ) 6.0 parts by mass, [F] 5.0 parts by mass (solid content) of (F-4) as a high fluorine content resin, and [E] (E-1)/(E-2) as a solvent.
• a radiation-sensitive resin composition (J- 64) was prepared.
• TWINSCAN XT-1900i manufactured by ASML
• NA 1.35
• the resist pattern using the above negative-working radiation-sensitive resin composition for ArF exposure was evaluated in the same manner as the evaluation of the resist pattern using the above-mentioned positive-working radiation-sensitive resin composition for ArF exposure.
• the radiation-sensitive resin composition of Example 64 had good sensitivity, CDU performance, and pattern circularity even when a negative resist pattern was formed by ArF exposure.
• Example 65 [A] 100 parts by mass of (A-15) as a resin, [B] 30.0 parts by mass of (B-1) as a first onium salt compound, [D] (D-7 as a second onium salt compound) ) 5.0 parts by mass, [F] 3.0 parts by mass (solid content) of (F-5) as a high fluorine content resin, [E] (E-1)/(E-4) as a solvent (
• a radiation-sensitive resin composition (J-65) was prepared by mixing 6,110 parts by mass of a mixed solvent of 4280/1830 (each part by mass) and filtering the mixture through a membrane filter with a pore size of 0.2 ⁇ m.
• a lower antireflection film having an average thickness of 105 nm was formed by heating at 205° C. for 60 seconds.
• the negative-tone radiation-sensitive resin composition for EUV exposure (J-65) prepared above was applied onto this lower antireflection film using the spin coater, and PB was performed at 130° C. for 60 seconds. Thereafter, a resist film having an average thickness of 55 nm was formed by cooling at 23° C. for 30 seconds.
• NXE3300 manufactured by ASML
• the sensitivity and CDU performance of the resist pattern using the above negative-working radiation-sensitive resin composition for EUV exposure were evaluated in the same manner as the evaluation of the resist pattern using the above-mentioned positive-working radiation-sensitive resin composition for ArF exposure.
• the radiation-sensitive resin composition of Example 65 had good sensitivity and CDU performance even when a negative resist pattern was formed by EUV exposure.
• the radiation-sensitive resin composition and resist pattern forming method described above it is possible to form a resist pattern that has good sensitivity to exposure light and is excellent in CDU performance, pattern circularity, and LWR performance. Therefore, these can be suitably used in the processing of semiconductor devices, which are expected to be further miniaturized in the future.

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