Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C381/00—Compounds containing carbon and sulfur and having functional groups not covered by groups C07C301/00 - C07C337/00
  • C07C381/12—Sulfonium compounds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C59/00—Compounds having carboxyl groups bound to acyclic carbon atoms and containing any of the groups OH, O—metal, —CHO, keto, ether, groups, groups, or groups
  • C07C59/01—Saturated compounds having only one carboxyl group and containing hydroxy or O-metal groups
  • C07C59/115—Saturated compounds having only one carboxyl group and containing hydroxy or O-metal groups containing halogen
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C61/00—Compounds having carboxyl groups bound to carbon atoms of rings other than six-membered aromatic rings
  • C07C61/16—Unsaturated compounds
  • C07C61/28—Unsaturated compounds polycyclic
  • C07C61/29—Unsaturated compounds polycyclic having a carboxyl group bound to a condensed ring system
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07J—STEROIDS
  • C07J9/00—Normal steroids containing carbon, hydrogen, halogen or oxygen substituted in position 17 beta by a chain of more than two carbon atoms, e.g. cholane, cholestane, coprostane
• • 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
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
• • 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
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
• • 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

Definitions

• the present invention relates to a radiation-sensitive resin composition and a pattern forming method.
• Photolithography technology that uses resist compositions is used to form fine circuits in semiconductor devices.
• an acid is generated by exposing the film of the resist composition to radiation through a mask pattern, and the acid is used as a catalyst to react with the resin in the exposed area and the unexposed area.
• a resist pattern is formed on a substrate by creating a difference in solubility in an organic solvent-based developer.
• CDU critical dimension uniformity
• the present invention in one embodiment, a resin containing a structural unit represented by the following formula (1) (hereinafter also referred to as “structural unit (I)”); one or more onium salts containing an organic acid anion portion and an onium cation portion; containing a solvent and
• the present invention relates to a radiation-sensitive resin composition containing an aromatic ring structure in which at least a portion of the onium cation moiety in the onium salt has a fluorine atom.
• R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms
• Y 1 is a divalent linking group
• X 1 is an acid dissociable group.
• the radiation-sensitive resin composition it is possible to construct a resist film that satisfies sensitivity, CDU performance, and development residue suppression. Although the reason for this is not clear, it is presumed as follows.
• the absorption of radiation such as EUV with a wavelength of 13.5 nm by fluorine atoms is very large, thereby increasing the sensitivity of the radiation-sensitive resin composition.
• the aromatic ring structure having a fluorine atom contained in the onium cation moiety enhances the water repellency of the resist film, suppresses intermixing between the resist film and its underlying film, and exhibits development residue suppressing properties.
• the acid-dissociable group possessed by the structural unit (I) in the resin has a high degree of freedom through a linking group or an ester bond, and thus has a high contact probability with an acid generated by exposure, thus facilitating an acid-dissociation reaction. happens to Therefore, the dissolution contrast between the exposed area and the unexposed area is increased, and excellent pattern formability is exhibited. It is presumed that the above resist performance can be exhibited by these combined actions.
• aromatic ring structure containing fluorine includes not only a structure in which a fluorine atom is directly bonded to an aromatic ring structure, but also a structure in which a fluorine atom is bonded to an aromatic ring structure via another atom (e.g., an aromatic ring structure (such as a structure in which a fluorine atom is bonded to a substituent that is bonded to ).
• the step of directly or indirectly applying the radiation-sensitive resin composition onto a substrate to form a resist film the step of directly or indirectly applying the radiation-sensitive resin composition onto a substrate to form a resist film; exposing the resist film; and developing the exposed resist film with a developer.
• the pattern forming method uses the radiation-sensitive resin composition, which is excellent in sensitivity, CDU performance, and development residue suppressing property, so that a high-quality resist pattern can be efficiently formed.
• the radiation-sensitive resin composition (hereinafter also simply referred to as "composition") according to this embodiment contains a resin, one or more onium salts, and a solvent.
• 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 can impart a high level of sensitivity, CDU performance and development residue suppression to the resulting resist film.
• the resin is an aggregate of polymers containing the structural unit (I) (hereinafter, this resin is also referred to as "base resin").
• the base resin includes, in addition to the structural unit (I), a structural unit having a phenolic hydroxyl group or a structural unit that gives a phenolic hydroxyl group by the action of an acid (hereinafter both are collectively referred to as “structural unit (II)”), It may contain a structural unit (III) containing a lactone structure or the like. Each structural unit will be described below.
• Structural unit (I) Structural unit (I) is represented by the following formula (1).
• R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms
• Y 1 is a divalent linking group
• X 1 is an acid dissociable group.
• the alkyl group having 1 to 5 carbon atoms represented by R is preferably a linear or branched alkyl group, specifically a methyl group, an ethyl group, a propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
• the halogenated alkyl group having 1 to 5 carbon atoms represented by R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms.
• the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is particularly preferred.
• the divalent linking group of Y 1 is not particularly limited, but preferable examples include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.
• a hydrocarbon group "having a substituent” means that some or all of the hydrogen atoms in the hydrocarbon group are substituted with substituents (groups or atoms other than hydrogen atoms).
• the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
• An aliphatic hydrocarbon group means a hydrocarbon group without aromaticity.
• the aliphatic hydrocarbon group as the divalent hydrocarbon group for Y 1 may be saturated or unsaturated, and is usually preferably saturated. More specific examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups and aliphatic hydrocarbon groups containing rings in their structures.
• the linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
• a straight - chain alkylene group is preferable, and specifically, a methylene group [--CH.sub.2--], an ethylene group [-- ( CH.sub.2) .sub.2-- ], a trimethylene group [ -(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], pentamethylene group [-(CH 2 ) 5 -] and the like.
• the branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2- , -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - and other alkylmethylene groups;- CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 Alkylethylene groups such as CH 3 ) 2 -CH 2 -; alkyltrimethylene groups such as -CH(CH 3 )CH 2 CH 2 - and -CH 2 CH(CH 3 )CH 2 -; -CH(CH 3 ) Examples include alkylalky
• the aliphatic hydrocarbon group containing a ring in the structure includes an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include those mentioned above.
• the alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
• the alicyclic hydrocarbon group may be polycyclic or monocyclic.
• the monocyclic alicyclic hydrocarbon group a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
• the polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
• the alicyclic hydrocarbon group may or may not have a substituent.
• An aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
• the aromatic hydrocarbon group as the divalent hydrocarbon group for Y 1 preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and 6 to 15 is particularly preferred and 6-10 is most preferred. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
• Specific examples of aromatic rings possessed by aromatic hydrocarbon groups include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; Atom-substituted heteroaromatic rings; and the like.
• the heteroatom in the aromatic heterocycle includes oxygen atom, sulfur atom, nitrogen atom and the like.
• the aromatic hydrocarbon group includes a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group ) in which one of the hydrogen atoms is substituted with an alkylene group (e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl such as 2-naphthylethyl group a group obtained by removing one hydrogen atom from the aryl group in the group); and the like.
• an alkylene group e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthy
• the alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
• the aromatic hydrocarbon group may or may not have a substituent.
• the heteroatom in the "heteroatom-containing divalent linking group" of Y 1 is an atom other than a carbon atom and a hydrogen atom, such as an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom and the like.
• Y 1 When Y 1 is -NH-, its H may be substituted with a substituent such as an alkyl group, an acyl group or an aryl group (aromatic group).
• Y 21 and Y 22 are each independently a divalent hydrocarbon group optionally having a substituent. Examples of the divalent hydrocarbon group include the same as those exemplified above as the “optionally substituted divalent hydrocarbon group” for Y 1 .
• Y 21 is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkylene group, more preferably a straight-chain alkylene group having 1 to 5 carbon atoms, particularly a methylene group or an ethylene group. preferable.
• Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group.
• the divalent linking group for Y 1 is particularly a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
• a linear or branched alkylene group or a divalent linking group containing a hetero atom is preferable.
• the acid-labile group represented by X1 means that at least the bond between the acid-labile group and an atom adjacent to the acid-labile group is cleaved by the action of an acid. It is a group having acid dissociation properties.
• the acid-dissociable group is not particularly limited, and includes a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth)acrylic acid or the like; an acetal-type acid-dissociable group such as an alkoxyalkyl group; Widely known.
• tertiary alkyl ester when an acid acts, the bond between the oxygen atom and the tertiary carbon atom is cleaved to form a carboxy group.
• the chain or cyclic alkyl group may have a substituent.
• a group that is acid-dissociable by forming a carboxy group and a tertiary alkyl ester is referred to as a "tertiary alkyl ester-type acid-dissociable group" for convenience.
• Examples of the tertiary alkyl ester-type acid-dissociable group include an aliphatic branched-chain acid-dissociable group and an acid-dissociable group containing an aliphatic cyclic group.
• aliphatic branched means having a branched structure without aromaticity.
• the structure of the "aliphatic branched acid-dissociable group” is not limited to a group composed of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. Also, the "hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
• Examples of aliphatic branched acid-labile groups include groups represented by —C(R 71 )(R 72 )(R 73 ).
• R 71 to R 73 are each independently a linear alkyl group having 1 to 5 carbon atoms.
• the group represented by —C(R 71 )(R 72 )(R 73 ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group and a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like.
• a tert-butyl group is particularly preferred.
• an "aliphatic cyclic group” indicates a monocyclic or polycyclic group having no aromatic character.
• the aliphatic cyclic group in the "acid-labile group containing an aliphatic cyclic group” may or may not have a substituent.
• the basic ring structure of the aliphatic cyclic group excluding substituents is not limited to a group composed of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. Also, the hydrocarbon group may be either saturated or unsaturated, but is usually preferably saturated.
• Aliphatic cyclic groups may be monocyclic or polycyclic. Aliphatic cyclic groups include, for example, groups obtained by removing one or more hydrogen atoms from monocycloalkane; and the like. Also, some of the carbon atoms constituting the ring of these alicyclic hydrocarbon groups may be substituted with ether bonds (--O--).
• Examples of the acid dissociable group containing an aliphatic cyclic group include groups represented by the following formulas (1-1) to (1-9) and the following formulas (2-1) to (2-6). mentioned.
• R 14 is an alkyl group and g is an integer of 0 to 8.
• R 15 and R 16 are each independently an alkyl group.
• the alkyl group for R 14 may be linear, branched or cyclic, preferably linear or branched.
• the linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms.
• the branched-chain alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms.
• Examples of the cyclic alkyl group include those similar to the aliphatic cyclic groups described above.
• g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and even more preferably 1 or 2.
• examples of alkyl groups for R 15 to R 16 include the same alkyl groups for R 14 above.
• some of the carbon atoms constituting the ring are substituted with etheric oxygen atoms (--O--) may Further, in formulas (1-1) to (1-9) and (2-1) to (2-6), hydrogen atoms bonded to carbon atoms constituting the ring may be substituted with substituents.
• An "acetal-type acid-dissociable group” generally replaces a hydrogen atom at the end of an OH-containing polar group such as a carboxy group or a hydroxyl group and bonds to an oxygen atom. Then, the acid acts to break the bond between the acetal-type acid-dissociable group and the oxygen atom to which the acetal-type acid-dissociable group is bonded, forming an OH-containing polar group such as a carboxy group or a hydroxyl group. be.
• X 1 in the above formula (1) is preferably represented by the following formula (s1) or (s2) in addition to the above acid dissociable group.
• Cy is an aliphatic cyclic group formed with a carbon atom.
• Ra 01 to Ra 03 each independently represents a hydrogen atom, a substituted or unsubstituted monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, or a substituted or unsubstituted monovalent is an aliphatic cyclic saturated hydrocarbon group, or represents an aliphatic cyclic structure formed by combining two or more of these with each other, provided that the aliphatic cyclic structure forms a crosslinked structure no.
• Cy is synonymous with the above formula (s1).
• Ra 04 is a substituted or unsubstituted aromatic hydrocarbon group. In the above formula, both * indicate a bond with an oxygen atom.
• the aliphatic cyclic group represented by Cy may be a monocyclic group or a polycyclic group.
• a monocyclic aliphatic cyclic group includes a group obtained by removing one or more hydrogen atoms from a monocycloalkane.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
• Polycyclic aliphatic cyclic groups include groups obtained by removing one or more hydrogen atoms from polycycloalkanes. Among these, a monocyclic aliphatic cyclic group is preferable, and a group obtained by removing one or more hydrogen atoms from cyclopentane or cyclohexane is more preferable.
• Some or all of the hydrogen atoms in the above aliphatic cyclic group may be substituted.
• examples of monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms in Ra 01 to Ra 03 include alkyl groups having 1 to 10 carbon atoms.
• examples of monovalent saturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms in Ra 01 to Ra 03 include monocyclic saturated aliphatic hydrocarbon groups and saturated polycyclic aliphatic hydrocarbon groups.
• Ra 01 to Ra 03 are particularly preferably hydrogen atoms from the viewpoint of ease of synthesizing the monomeric compound from which the structural unit (I) is derived.
• the chain saturated hydrocarbon group or aliphatic cyclic saturated hydrocarbon group represented by Ra 01 to Ra 03 may or may not have a substituent.
• the aliphatic cyclic group having no crosslinked structure represented by Cy in formula (s2) is the same as the aliphatic cyclic group represented by Cy in formula (s1).
• examples of the aromatic hydrocarbon group for Ra 04 include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms.
• Ra 04 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.
• R ⁇ represents a hydrogen atom, a methyl group or a trifluoromethyl group.
• R ⁇ represents a hydrogen atom, a methyl group or a trifluoromethyl group.
• the structural unit (I) is represented by the above formulas (a1-3-13) to (a1-3-24), (a1-3-33) to (a1-3-34), formula (a01- 1-01) to (a01-1-08), formulas (s1-1) to (s1-4), and formulas (s2-1) to (s1-6). is preferred.
• the content ratio of the structural unit (I) in the resin is preferably 10 mol% or more, more preferably 20 mol%, based on the total structural units constituting the resin. The above is more preferable, and 30 mol % or more is even more preferable.
• the content ratio is preferably 70 mol % or less, more preferably 60 mol % or less, and even more preferably 50 mol % or less.
• Structural unit (II) Structural unit (II) is a structural unit having a phenolic hydroxyl group or a structural unit giving a phenolic hydroxyl group by the action of an acid.
• the phenolic hydroxyl group of the structural unit (II) also includes a phenolic hydroxyl group that is deprotected by the action of an acid generated by exposure to light.
• the structural unit (II) improves etching resistance and contributes to the improvement of the developer solubility difference (dissolution contrast) between 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 and EUV.
• Structural unit (II) is preferably represented by the following formula (2).
• R ⁇ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• L CA is a single bond, -COO- * or -O-. * is a bond on the aromatic ring side.
• R 101 is a hydrogen atom or a protecting group that is deprotected by the action of an acid. When multiple R 101 are present, the multiple R 101 are the same or different.
• R 102 is a cyano group, nitro group, alkyl group, fluorinated alkyl group, alkoxycarbonyloxy group, acyl group or acyloxy group. When multiple R 102 are present, the multiple R 102 are the same or different from each other.
• n 3 is an integer of 0-2, m 3 is an integer of 1-8, and m 4 is an integer of 0-8. However, 1 ⁇ m 3 +m 4 ⁇ 2n 3 +5 is satisfied. )
• R ⁇ is preferably a hydrogen atom or a methyl group.
• LCA is preferably a single bond or -COO- * .
• Examples of the protective group represented by R 101 deprotected by the action of an acid include the same acid-labile groups as X 1 in formula (1) above.
• Examples of the alkyl group for R 102 include linear or branched alkyl groups having 1 to 8 carbon atoms such as methyl group, ethyl group and propyl group.
• Examples of the fluorinated alkyl group include linear or branched fluorinated alkyl groups having 1 to 8 carbon atoms such as trifluoromethyl group and pentafluoroethyl group.
• the alkoxycarbonyloxy group includes, for example, a chain or alicyclic alkoxycarbonyloxy group having 2 to 16 carbon atoms such as a methoxycarbonyloxy group, a butoxycarbonyloxy group and an adamantylmethyloxycarbonyloxy group.
• Acyl groups include, for example, aliphatic or aromatic acyl groups having 2 to 12 carbon atoms such as acetyl group, propionyl group, benzoyl group and acryloyl group.
• the acyloxy group includes, for example, aliphatic or aromatic acyloxy groups having 2 to 12 carbon atoms such as acetyloxy group, propionyloxy group, benzoyloxy group and acryloyloxy group.
• n3 0 or 1 is more preferable, and 0 is even more preferable.
• m 3 is preferably an integer of 1 to 3, more preferably 1 or 2.
• m 4 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2.
• structural units (2a-1) to (2a-10) hereinafter also referred to as “structural units (2a-1) to structural units (2a-10)” .
• structural units (2a-1) to structural units (2a-10) hereinafter also referred to as “structural units (2a-1) to structural units (2a-10)” .
• R ⁇ is the same as in formula (2) above.
• the structural units (2a-1) to (2a-4), (2a-6), (2a-8) and (2a-9) are preferred.
• the content ratio of the structural unit (II) (total when multiple types of structural units (II) are present) is preferably 5 mol% or more, more preferably 8 mol% or more, based on the total structural units constituting the resin. Preferably, 10 mol % or more is more preferable, and 15 mol % or more is particularly preferable.
• the content is preferably 50 mol % or less, more preferably 40 mol % or less, even more preferably 35 mol % or less, and particularly preferably 30 mol % or less.
• the phenolic hydroxyl group is protected by a protective group such as an alkali-dissociable group, and then polymerized, and then hydrolyzed to deprotect. It is preferred to obtain the structural unit (II).
• Structural unit (III) 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.
• the adhesion between the resist pattern formed from the base resin and the substrate can be improved.
• Structural units (III) include, for example, 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 each independently represent 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; be.
• R L4 and R L5 may be a divalent alicyclic group having 3 to 8 carbon atoms combined with each other and composed together with the carbon atoms to which they are attached.
• L2 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 of 1-3.
• the divalent alicyclic group having 3 to 8 carbon atoms in which the above R 1 L4 and R 1 L5 are combined and formed together with the carbon atoms to which they are bonded is the above-mentioned monocyclic or polycyclic alicyclic carbonized carbon atoms.
• Either a monocyclic hydrocarbon group or a polycyclic hydrocarbon group may be used, and the polycyclic hydrocarbon group may be either a bridged alicyclic hydrocarbon group or a condensed alicyclic hydrocarbon group. It may be either a hydrogen group or an unsaturated hydrocarbon group.
• the condensed alicyclic hydrocarbon group is a polycyclic alicyclic hydrocarbon group in which a plurality of alicyclic rings share a side (a bond between two adjacent carbon atoms).
• 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.
• 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- may be mentioned.
• a structural unit containing a lactone structure is preferable, a structural unit containing a norbornanelactone structure is more preferable, and a structural unit derived from norbornanelactone-yl (meth)acrylate is even more preferable.
• the content of the structural unit (III) (total when multiple types of the structural unit (III) are present) is preferably 5 mol% or more, more preferably 10 mol% or more, based on the total structural units constituting the base resin. More preferably, 15 mol % or more is even more preferable.
• the content ratio is preferably 50 mol % or less, more preferably 40 mol % or less, and even more preferably 35 mol % or less.
• the base resin optionally has other structural units in addition to the structural units (I) to (III).
• the other structural units include structural units (IV) containing a polar group (excluding structural units (II) and (III)) and other structural units having an acid-dissociable group. (V) (excluding those corresponding to the structural unit (I)), and the like.
• the base resin can adjust the solubility in the developer, and as a result, the lithography performance such as the resolution of the radiation-sensitive resin composition can be improved.
• the polar group include a hydroxy group, a carboxyl group, a cyano group, a nitro group, a sulfonamide group and the like. Among these, a hydroxy group and a carboxy group are preferred, and a hydroxy group is more preferred.
• Structural units (IV) include, for example, structural units represented by the following formula.
• RA is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• the lower limit of the content ratio of the structural unit (IV) (the total when there are multiple types of the structural unit (IV)) is , 1 mol % is preferred, 5 mol % is more preferred, and 10 mol % is even more preferred.
• the upper limit of the content ratio is preferably 40 mol %, more preferably 30 mol %, and even more preferably 25 mol %.
• Structural unit (V) is a structural unit containing an acid-labile group (but different from structural unit (I) and structural unit (II)).
• the structural unit (V) is not particularly limited as long as it contains an acid-dissociable group. and a structural unit having an acetal bond. From the viewpoint of improving the pattern formability of the radiation-sensitive resin composition, a structural unit represented by the following formula (3) (hereinafter referred to as "structure Unit (V-1)”) is preferred.
• R7 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• R 8 is a monovalent hydrocarbon group having 1 to 20 carbon atoms.
• R 9 and R 10 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 which is combined with the carbon atoms to which they are bonded.
• R 7 is preferably a hydrogen atom or a methyl group, more preferably a methyl group, from the viewpoint of copolymerizability of the monomer that gives the structural unit (V-1).
• Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 8 include a chain hydrocarbon group having 1 to 10 carbon atoms and a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. groups, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, and the like.
• the chain hydrocarbon group having 1 to 10 carbon atoms represented by R 8 to R 10 includes 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.
• a branched chain unsaturated hydrocarbon group is mentioned.
• Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R 8 to R 10 include monocyclic or polycyclic saturated hydrocarbon groups and monocyclic or polycyclic unsaturated hydrocarbon groups. be done.
• Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R 8 include aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group and anthryl group; benzyl group and phenethyl group; , an aralkyl group such as a naphthylmethyl group, and the like.
• R 8 above includes a linear or branched saturated hydrocarbon group having 1 to 5 carbon atoms, a linear or branched unsaturated hydrocarbon group having 1 to 5 carbon atoms, and an alicyclic hydrocarbon having 3 to 12 carbon atoms.
• a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms is preferred.
• the divalent alicyclic group having 3 to 20 carbon atoms in which the groups represented by R 9 and R 10 are combined together and formed together with the carbon atoms to which they are bonded are monocyclic hydrocarbon groups and polycyclic hydrocarbon groups. Any hydrocarbon group may be used.
• R 8 is an alkyl group having 1 to 4 carbon atoms
• R 9 and R 10 are combined together and the alicyclic structure composed of the carbon atom to which they are attached is a polycyclic or monocyclic cycloalkane.
• a structure is preferred.
• structural unit (V-1) for example, structural units represented by the following formulas (3-1) to (3-6) (hereinafter referred to as “structural units (V-1-1) to (V-1- 6)”) and the like.
• R 7 to R 10 have the same meanings as in formula (3) above.
• i and j are each independently an integer of 1 to 4;
• k and l are 0 or 1;
• R8 is preferably a methyl group, an ethyl group or an isopropyl group.
• R 9 and R 10 are preferably a methyl group or an ethyl group.
• the base resin may contain one or a combination of two or more structural units (V).
• the lower limit of the content ratio of the structural unit (V) (the total content ratio when multiple types are included) is 3 mol% with respect to the total structural units constituting the base resin. is preferred, 5 mol % is more preferred, and 10 mol % is even more preferred.
• the upper limit of the content ratio is preferably 50 mol %, more preferably 40 mol %, and even more preferably 30 mol %.
• the resin serving as the base resin can be synthesized, for example, by polymerizing monomers that provide each structural unit using a known radical polymerization initiator or the like in an appropriate solvent.
• the molecular weight of the base resin is not particularly limited, but the lower limit of the polystyrene equivalent weight average molecular weight (Mw) by gel permeation chromatography (GPC) is preferably 1,000, more preferably 2,000, and further 3,000. Preferably, 4,000 is particularly preferred. Moreover, the upper limit of Mw is preferably 50,000, more preferably 30,000, even more preferably 15,000, and particularly preferably 12,000. When the Mw of the resin is within the above range, the obtained resist film has good heat resistance and developability.
• Mw polystyrene equivalent weight average molecular weight
• the ratio (Mw/Mn) of Mw to the polystyrene equivalent number average molecular weight (Mn) measured 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 resin content is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, relative to the total solid content of the radiation-sensitive resin composition.
• the radiation-sensitive resin composition of the present embodiment may contain, as another resin, a resin having a higher mass content of fluorine atoms than the base resin (hereinafter also referred to as "high fluorine content resin"). good.
• high fluorine content resin a resin having a higher mass content of fluorine atoms than the base resin.
• the structural unit (I) to the structural unit (V) in the base resin may be used singly or in combination, and a structural unit represented by the following formula (6) (hereinafter referred to as , also referred to as “structural unit (VI)”).
• R 13 is a hydrogen atom, a methyl group or a trifluoromethyl group.
• G is a single bond, an oxygen atom, a sulfur atom, -COO-, -SO 2 ONH-, -CONH- or -OCONH-.
• 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.
• the lower limit of the content of the structural unit (VI) is preferably 50 mol%, preferably 60%, based on the total structural units constituting the high fluorine content resin. mol % is more preferred, 70 mol % is even more preferred, and 80 mol % is particularly preferred.
• the upper limit of the content ratio is preferably 100 mol %, more preferably 98 mol %, and even more preferably 95 mol %.
• the high fluorine content resin has a structural unit (x) an alkali-soluble group or (y) a group dissociated by the action of an alkali to increase the solubility in an alkaline developer (hereinafter referred to as Also referred to as a structural unit (VII)).
• a structural unit (VII) By having the structural unit (VII), the high fluorine content resin can improve the solubility in an alkaline developer and suppress the occurrence of development defects.
• the lower limit of the content of the structural unit (VII) is preferably 10 mol%, 20 mol % is more preferred, 30 mol % is even more preferred, and 35 mol % is particularly preferred.
• the upper limit of the content ratio is preferably 90 mol %, more preferably 75 mol %, and even more preferably 60 mol %.
• the lower limit of the content of the high fluorine content resin is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, still more preferably 1 part by mass, and 1.5 parts by mass with respect to 100 parts by mass of the base resin. Parts by weight are particularly preferred.
• the upper limit of the content is preferably 12 parts by mass, more preferably 10 parts by mass, still more preferably 8 parts by mass, and particularly preferably 5 parts by mass.
• the high fluorine content resin can be synthesized by a method similar to the method for synthesizing the base resin described above.
• the onium salt contains an organic acid anion portion and an onium cation portion, and is a component that generates an acid upon exposure.
• the onium cation portion in the onium salt contains an aromatic ring structure having a fluorine atom, it is possible to achieve high sensitivity and development residue suppression properties by improving the efficiency of acid generation.
• the form of the onium salt contained in the radiation-sensitive resin composition is not particularly limited. It is preferably at least one selected from the group consisting of acid diffusion control agents that contain the above onium cation moiety and generate an acid having a higher pKa than the acid generated from the above radiation-sensitive acid generator upon exposure to radiation. . Each of these functions is described below.
• the acid generated by exposure to the onium salt is considered to have two functions in the radiation-sensitive resin composition depending on the strength of the acid.
• the first function the acid generated by exposure dissociates the acid-dissociable group of the structural unit when the resin contains a structural unit having an acid-labile group to generate a carboxyl group or the like. be done.
• An onium salt having this first function is called a radiation-sensitive acid generator.
• the acid-dissociable groups of the resin are not substantially dissociated, and are generated from the radiation-sensitive acid generator in the unexposed areas. The function of suppressing the diffusion of the acid that has been added by salt exchange is exemplified.
• an onium salt having this second function is called an acid diffusion controller. It can be said that the acid generated from the acid diffusion control agent is a relatively weak acid (acid having a high pKa) than the acid generated from the radiation-sensitive acid generator. Whether the onium salt functions as a radiation-sensitive acid generator or an acid diffusion control agent is determined by the energy required for dissociation of the acid dissociable group of the resin, the acidity of the onium salt, and the like.
• the form in which the radiation-sensitive acid generator is contained in the radiation-sensitive resin composition is preferably a form in which the onium salt structure exists alone as a (low-molecular-weight) compound.
• the radiation-sensitive resin composition contains the radiation-sensitive acid generator, the polarity of the resin in the exposed area increases, and the resin in the exposed area becomes soluble in the developer in the case of alkaline aqueous solution development. On the other hand, in the case of organic solvent development, it becomes sparingly soluble in the developer.
• the radiation-sensitive resin composition contains the acid diffusion control agent, it is possible to suppress the diffusion of the acid in the unexposed area, thereby forming a resist pattern having excellent pattern developability and CDU performance. can.
• At least one of the organic acid anion moiety in the radiation-sensitive acid generator and the organic acid anion moiety in the acid diffusion controller preferably contains an iodine-substituted aromatic ring structure.
• Absorption of radiation such as EUV with a wavelength of 13.5 nm by iodine atoms is very large, thereby increasing the sensitivity.
• the organic acid anion portion of the onium salt contains an iodine-substituted aromatic ring structure, the molecular weight of the iodine atom can control acid diffusion and improve the CDU performance.
• the organic acid anion portion of the onium salt contains an iodine-substituted aromatic ring structure
• the iodine-substituted aromatic ring structure and the fluorine atom-containing aromatic ring structure may be present in the same compound, or may be present in different compounds. good too.
• the organic acid anion portion preferably has at least one selected from the group consisting of sulfonate anions, carboxylate anions and sulfonimide anions.
• the onium cation is preferably at least one selected from the group consisting of sulfonium cations and iodonium cations.
• Examples of the acid generated by exposure include those that generate sulfonic acid, carboxylic acid, and sulfonimide by exposure corresponding to the above organic acid anions.
• an onium salt that gives a sulfonic acid by exposure (1) compounds in which one or more fluorine atoms or fluorinated hydrocarbon groups are attached to carbon atoms adjacent to the sulfonate anion; (2) A compound in which neither a fluorine atom nor a fluorinated hydrocarbon group is bonded to the carbon atom adjacent to the sulfonate anion.
• those corresponding to (1) above are preferable as the radiation-sensitive acid generator.
• those corresponding to the above (2), (3) or (4) are preferable, and those corresponding to (2) or (4) are particularly preferable.
• Onium salts as radiation-sensitive acid generators contain an organic acid anion moiety and an onium cation moiety.
• the radiation-sensitive acid generator is preferably represented by formula (A-1) or formula (A-2) below.
• L 1 is a single bond, an ether bond or an ester bond, or an alkylene group having 1 to 6 carbon atoms which may contain an ether bond or an ester bond.
• the alkylene group may be linear, branched, or cyclic.
• R 1 is a hydroxy group, a carboxy group, a fluorine atom, a chlorine atom, a bromine atom or an amino group, or a fluorine atom, a chlorine atom, a bromine atom, a hydroxy group, an amino group or an alkoxy group having 1 to 10 carbon atoms;
• R 8 is a hydrogen atom, a halogen atom, a hydroxy group, a carbon an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms which may contain an acyloxy group having 2 to 6 carbon atoms; 16 alkyl group, alkenyl group having 2 to 16 carbon atoms, or aryl group having 6 to 12 carbon atoms, halogen atom, hydroxy group, alkoxy group having 1 to 6 carbon atoms, acyl group having 2 to 6 carbon atoms, Alternatively, it may contain an acyloxy group having 2 to 6 carbon atoms.
• R 2 is a single bond or a divalent linking group having 1 to 20 carbon atoms when p is 1, and a trivalent or tetravalent linking group having 1 to 20 carbon atoms when p is 2 or 3. and the linking group may contain an oxygen atom, a sulfur atom or a nitrogen atom.
• Rf 1 to Rf 4 are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, at least one of which is a fluorine atom or a trifluoromethyl group. Also, Rf 1 and Rf 2 may combine to form a carbonyl group. In particular, both Rf3 and Rf4 are preferably fluorine atoms.
• R 3 , R 4 , R 5 , R 6 and R 7 are each independently a C 1-20 monovalent hydrocarbon group optionally containing a heteroatom.
• R 3 , R 4 and R 5 contain one or more fluorine atoms
• R 6 and R 7 contain one or more fluorine atoms.
• any two of R 3 , R 4 and R 5 may bond with each other to form a ring together with the sulfur atom to which they bond.
• the monovalent hydrocarbon group may be linear, branched, or cyclic, and specific examples thereof include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkenyl group having 2 to 12 carbon atoms.
• an aryl group having 6 to 20 carbon atoms an aralkyl group having 7 to 12 carbon atoms, and the like.
• some or all of the hydrogen atoms in these groups are substituted with hydroxy groups, carboxy groups, halogen atoms, cyano groups, amido groups, nitro groups, mercapto groups, sultone groups, sulfone groups, or sulfonium salt-containing groups. and some of the carbon atoms of these groups may be substituted with ether bonds, ester bonds, carbonyl groups, carbonate groups or sulfonate ester bonds.
• p is an integer that satisfies 1 ⁇ p ⁇ 3.
• q and r are integers satisfying 0 ⁇ q ⁇ 5, 0 ⁇ r ⁇ 3, and 0 ⁇ q+r ⁇ 5.
• q is preferably an integer that satisfies 1 ⁇ q ⁇ 3, more preferably 2 or 3.
• r is preferably an integer that satisfies 0 ⁇ r ⁇ 2.
• Examples of the organic acid anion portion of the radiation-sensitive acid generator represented by the above formulas (A-1) and (A-2) include, but are not limited to, those shown below. All of the compounds shown below are organic acid anion moieties having an iodine-substituted aromatic ring structure. A structure substituted with an atom or group other than an iodine atom such as a substituent of can be preferably employed.
• the onium cation moiety in the radiation-sensitive acid generator represented by formula (A-1) above is preferably represented by formula (Q-1) below.
• Ra1 and Ra2 each independently represent a substituent.
• n1 represents an integer of 0 to 5, and when n1 is 2 or more, a plurality of Ra1 may be the same or different.
• n2 represents an integer of 0 to 5, and when n2 is 2 or more, a plurality of Ra2 may be the same or different.
• n3 represents an integer of 0 to 5, and when n3 is 2 or more, a plurality of Ra3 may be the same or different.
• Ra3 represents a fluorine atom or a group having one or more fluorine atoms.
• Ra1 and Ra2 may be linked together to form a ring. When n1 is 2 or more, a plurality of Ra1 may be linked together to form a ring. When n2 is 2 or more, a plurality of Ra2 may be linked together to form a ring.
• the substituents represented by Ra1 and Ra2 are preferably alkyl groups, cycloalkyl groups, alkoxy groups, cycloalkyloxy groups, alkoxycarbonyl groups, alkylsulfonyl groups, hydroxyl groups, halogen atoms, and halogenated hydrocarbon groups.
• the alkyl groups of Ra1 and Ra2 may be straight-chain alkyl groups or branched-chain alkyl groups.
• the alkyl group preferably has 1 to 10 carbon atoms, and particularly preferably methyl group, ethyl group, n-butyl group and t-butyl group.
• Cycloalkyl groups for Ra1 and Ra2 include monocyclic or polycyclic cycloalkyl groups (preferably cycloalkyl groups having 3 to 20 carbon atoms). Among these, cyclopropyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group are particularly preferred.
• alkyl group portion of the alkoxy groups of Ra1 and Ra2 examples include those previously listed as the alkyl groups of Ra1 and Ra2.
• this alkoxy group a methoxy group, an ethoxy group, an n-propoxy group and an n-butoxy group are particularly preferred.
• Examples of the cycloalkyl group portion of the cycloalkyloxy groups of Ra1 and Ra2 include those previously listed as the cycloalkyl groups of Ra1 and Ra2.
• a cyclopentyloxy group and a cyclohexyloxy group are particularly preferred as the cycloalkyloxy group.
• alkoxy group portion of the alkoxycarbonyl groups of Ra1 and Ra2 examples include those previously listed as the alkoxy groups of Ra1 and Ra2.
• this alkoxycarbonyl group a methoxycarbonyl group, an ethoxycarbonyl group and an n-butoxycarbonyl group are particularly preferred.
• Examples of the alkyl group portion of the alkylsulfonyl groups of Ra1 and Ra2 include those previously listed as the alkyl groups of Ra1 and Ra2.
• examples of the cycloalkyl group portion of the cycloalkylsulfonyl groups of Ra1 and Ra2 include those previously listed as the cycloalkyl groups of Ra1 and Ra2.
• alkylsulfonyl groups and cycloalkylsulfonyl groups methanesulfonyl group, ethanesulfonyl group, n-propanesulfonyl group, n-butanesulfonyl group, cyclopentanesulfonyl group and cyclohexanesulfonyl group are particularly preferred.
• Each group of Ra1 and Ra2 may further have a substituent.
• substituents include a halogen atom such as a fluorine atom (preferably a fluorine atom), a hydroxy group, a carboxyl group, a cyano group, a nitro group, an alkoxy group, a cycloalkyloxy group, an alkoxyalkyl group, and a cycloalkyloxyalkyl group. , alkoxycarbonyl, cycloalkyloxycarbonyl, alkoxycarbonyloxy, and cycloalkyloxycarbonyloxy groups.
• the halogen atoms of Ra1 and Ra2 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, with a fluorine atom being preferred.
• Halogenated alkyl groups are preferred as the halogenated hydrocarbon groups for Ra1 and Ra2.
• alkyl group and halogen atom that constitute the halogenated alkyl group include those mentioned above. Among them, a fluorinated alkyl group is preferred, and CF3 is more preferred.
• Ra1 and Ra2 may be linked together to form a ring (ie, a heterocyclic ring containing a sulfur atom).
• Ra1 and Ra2 preferably form a single bond or a divalent linking group.
• n1 is 2 or more
• a plurality of Ra1 may be linked together to form a ring
• n2 is 2 or more
• a plurality of Ra2 may be linked together to form a ring.
• Such an example includes, for example, a mode in which two Ra1s are linked to each other to form a naphthalene ring together with the benzene ring to which they are linked.
• Ra3 is a fluorine atom or a group having a fluorine atom.
• groups having fluorine atoms include groups in which alkyl groups, cycloalkyl groups, alkoxy groups, cycloalkyloxy groups, alkoxycarbonyl groups and alkylsulfonyl groups as Ra1 and Ra2 are substituted with fluorine atoms.
• fluorinated alkyl groups are preferable, and CF 3 , C 2 F 5 , C 3 F 7 , C 4 F 9 , C 5 F 11 , C 6 F 13 , C 7 F 15 and C 8 F 17 , CH2CF3 , CH2CH2CF3 , CH2C2F5 , CH2CH2C2F5 , CH2C3F7 , CH2CH2C3F7 , CH2C4F _ _ _ _ _ _ _ _ 9 and CH 2 CH 2 C 4 F 9 are more preferred, and CF 3 is particularly preferred.
• Ra3 is preferably a fluorine atom or CF3 , more preferably a fluorine atom.
• n1 and n2 are each independently preferably an integer of 0 to 3, preferably an integer of 0 to 2.
• n3 is preferably an integer of 1 to 3, more preferably 1 or 2.
• (n1+n2+n3) is preferably an integer of 1 to 15, more preferably an integer of 1 to 9, even more preferably an integer of 2 to 6, and particularly preferably an integer of 3 to 6.
• (n1+n2+n3) 2
• (n1+n2+n3) 3
• onium cation moiety represented by the above formula (Q-1) include the following. All of the compounds shown below are sulfonium cation moieties containing an aromatic ring structure having a fluorine atom. is substituted with an atom or group other than a fluorine atom such as a hydrogen atom or another substituent.
• the onium cation moiety in the radiation-sensitive acid generator represented by formula (A-2) contains an aromatic ring structure having a fluorine atom
• the onium cation moiety is a diaryliodonium cation having one or more fluorine atoms.
• the onium cation moiety is a diaryliodonium cation having one or more fluorine atoms.
• onium cation moieties include the following. All of the compounds shown below are iodonium cation moieties containing an aromatic ring structure having a fluorine atom. is substituted with an atom or group other than a fluorine atom such as a hydrogen atom or another substituent.
• the methods for synthesizing the radiation-sensitive acid generators represented by the above formulas (A-1) and (A-2) can also be performed by known methods, particularly by salt exchange reaction.
• a known radiation-sensitive acid generator can also be used as long as it does not impair the effects of the present invention.
• the lower limit of the content of the radiation-sensitive acid generator is preferably 0.5 parts by mass, more preferably 1 part by mass, still more preferably 2 parts by mass, and particularly preferably 4 parts by mass, relative to 100 parts by mass of the base resin.
• the upper limit of the content is preferably 20 parts by mass, more preferably 18 parts by mass, still more preferably 15 parts by mass, and particularly preferably 12 parts by mass.
• the onium salt as the acid diffusion control agent contains an organic acid anion portion and an onium cation portion, and generates an acid having a higher pKa than the acid generated from the radiation-sensitive acid generator upon exposure to radiation.
• the acid diffusion control agent is preferably represented by the following formula (S-1) or the following formula (S-2).
• R 1A is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms
• R 1B is an alkyl group having 1 to 6 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.
• R 3 , R 4 , R 5 , R 6 and R 7 are each independently a C 1-20 monovalent hydrocarbon group optionally containing a heteroatom.
• R 3 , R 4 and R 5 are preferably monovalent hydrocarbon groups containing one or more fluorine atoms or groups having fluorine atoms
• R 6 and R 7 are one or more fluorine atoms or fluorine atoms It is preferably a monovalent hydrocarbon group containing a group having Also, any two of R 3 , R 4 and R 5 may bond with each other to form a ring together with the sulfur atom to which they bond.
• the monovalent hydrocarbon group may be linear, branched, or cyclic, and specific examples thereof include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkenyl group having 2 to 12 carbon atoms. , an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and the like. Also, some or all of the hydrogen atoms in these groups may be substituted with substituents.
• L 1 is a single bond or a divalent linking group having 1 to 20 carbon atoms, and is an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxy group or a carboxy may contain groups.
• n and n are integers satisfying 0 ⁇ m ⁇ 5, 0 ⁇ n ⁇ 3, and 0 ⁇ m+n ⁇ 5, but integers satisfying 1 ⁇ m ⁇ 3 and 0 ⁇ n ⁇ 2 are preferable.
• the anions of the acid diffusion control agent represented by the above formula (S-1) or (S-2) include, but are not limited to, those shown below. All of the compounds shown below are organic acid anion moieties having an iodine-substituted aromatic ring structure. A structure substituted with an atom or group other than an iodine atom such as a substituent of can be preferably employed.
• the onium cation moiety in the radiation-sensitive acid generator can be suitably employed as the onium cation moiety in the acid diffusion controller represented by formulas (S-1) and (S-2).
• the acid diffusion controllers represented by the above formulas (S-1) and (S-2) can also be synthesized by known methods, particularly by salt exchange reaction. Known acid diffusion control agents can also be used as long as they do not impair the effects of the present invention. In addition, the case where the organic acid anion portion and the onium cation portion share the same aromatic ring structure is also included in the acid diffusion control agent of the present embodiment.
• the acid diffusion control agents may be used alone or in combination of two or more.
• the lower limit of the content of the acid diffusion control agent is preferably 0.5 parts by mass, more preferably 1 part by mass, and even more preferably 1.5 parts by mass with respect to 100 parts by mass of the base resin.
• the upper limit of the content is preferably 15 parts by mass, more preferably 12 parts by mass, and even more preferably 8 parts by mass.
• Radiation-sensitive acid generators including both radiation-sensitive strong acid generators and acid diffusion controllers are organic acid anion moieties represented by the above formulas (A-1) and (A-2). Together with or instead of the organic acid anion portion of the radioactive strong acid generator or the organic acid anion portion of the acid diffusion control agent represented by the above formula (S-1) or (S-2), the following formula (bd1) It may contain structures as depicted.
• R x1 to R x4 each independently represent a hydrogen atom, a substituted or unsubstituted hydrocarbon group, or a ring structure formed by combining two or more of these.
• R y1 to R y2 each independently represent a hydrogen atom, a substituted or unsubstituted hydrocarbon group, or a ring structure formed by combining with each other. is a double bond or a single bond.
• R z1 to R z4 each independently represent a hydrogen atom, a substituted or unsubstituted hydrocarbon group, or a ring structure formed by combining two or more of these.
• at least one of R x1 to R x4 , R y1 to R y2 and R z1 to R z4 has an acid anion structure.
• the hydrocarbon groups in R x1 to R x4 , R y1 to R y2 and R z1 to R z4 may each be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a cyclic hydrocarbon group, or a chain It may be a hydrocarbon group having a shape.
• the hydrocarbon group which may have a substituent in R x1 to R x4 , R y1 to R y2 and R z1 to R z4 includes a cyclic group which may have a substituent and a substituent.
• a chain alkyl group which may have a chain, or a chain alkenyl group which may have a substituent may be mentioned.
• the cyclic group which may have a substituent is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
• An aliphatic hydrocarbon group means a hydrocarbon group without aromaticity.
• the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
• the cyclic hydrocarbon groups in R x1 to R x4 , R y1 to R y2 and R z1 to R z4 may contain heteroatoms such as heterocycles.
• the aromatic hydrocarbon groups in R x1 to R x4 , R y1 to R y2 and R z1 to R z4 are hydrocarbon groups having an aromatic ring.
• the aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and particularly preferably 6 to 15 carbon atoms, 6 to 12 carbon atoms are most preferred. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
• aromatic rings possessed by aromatic hydrocarbon groups in R x1 to R x4 , R y1 to R y2 and R z1 to R z4 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic rings thereof. and aromatic heterocycles in which some of the carbon atoms constituting are substituted with hetero atoms.
• aromatic hydrocarbon groups for R x1 to R x4 , R y1 to R y2 and R z1 to R z4 include groups obtained by removing one hydrogen atom from the above aromatic rings.
• the cyclic aliphatic hydrocarbon group for R x1 to R x4 , R y1 to R y2 and R z1 to R z4 includes an aliphatic hydrocarbon group containing a ring in its structure.
• the aliphatic hydrocarbon group containing a ring in this structure includes an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group.
• the alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.
• the alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group.
• the cyclic aliphatic hydrocarbon group for R x1 to R x4 , R y1 to R y2 and R z1 to R z4 is preferably a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane. .
• the linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group, preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. is more preferred, and those with 1 to 3 carbon atoms are most preferred.
• the branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, and 3 or 4 carbon atoms. is more preferred, and one having 3 carbon atoms is most preferred.
• substituents in the cyclic groups R x1 to R x4 , R y1 to R y2 and R z1 to R z4 include alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, nitro groups and carbonyl groups. etc.
• the chain alkyl groups of R x1 to R x4 , R y1 to R y2 and R z1 to R z4 may be linear or branched.
• the linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms.
• the branched-chain alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms.
• the chain alkenyl groups represented by R x1 to R x4 , R y1 to R y2 and R z1 to R z4 may be linear or branched and preferably have 2 to 10 carbon atoms, It preferably has 2 to 5 carbon atoms, more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms.
• substituents on the chain alkyl or alkenyl groups of R x1 to R x4 , R y1 to R y2 and R z1 to R z4 include alkoxy groups, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, atoms, etc.), halogenated alkyl groups, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and cyclic groups for the above R x1 to R x4 , R y1 to R y2 and R z1 to R z4 .
• the hydrocarbon groups for R x1 to R x4 , R y1 to R y2 and R z1 to R z4 are, among the above hydrocarbon groups, optionally substituted cyclic groups and substituted A chain alkyl group which may be substituted is preferred.
• R y1 to R y2 may be bonded to each other to form a ring structure.
• This ring structure may be an alicyclic hydrocarbon or an aromatic hydrocarbon. Also, this ring structure may be a polycyclic structure consisting of other ring structures.
• the alicyclic hydrocarbon formed by R y1 to R y2 may be polycyclic or monocyclic.
• a monocycloalkane is preferred as the monocyclic alicyclic hydrocarbon.
• Polycycloalkanes are preferred as polycyclic alicyclic hydrocarbons.
• the aromatic hydrocarbon ring formed by R y1 to R y2 is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heteroaromatic ring in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. rings and the like.
• the ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by R y1 to R y2 may have a substituent.
• substituents here include those similar to the substituents for the aforementioned cyclic groups R x1 to R x4 , R y1 to R y2 and R z1 to R z4 .
• the ring structure formed by R y1 to R y2 is more preferably an aromatic hydrocarbon which may have a substituent, from the viewpoints of short diffusion of acid generated by exposure and controllability of acid diffusion.
• R z1 to R z4 may be mutually bonded to form a ring structure.
• R z1 may form a ring structure with any of R z2 to R z4 .
• the ring structure may be an alicyclic hydrocarbon or an aromatic hydrocarbon.
• the alicyclic hydrocarbon formed by two or more of R z1 to R z4 may be polycyclic or monocyclic.
• a monocycloalkane is preferred as the monocyclic alicyclic hydrocarbon.
• Polycycloalkanes are preferred as polycyclic alicyclic hydrocarbons.
• the aromatic hydrocarbon ring formed by two or more of R z1 to R z4 is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or some of the carbon atoms constituting these aromatic rings are heteroatoms.
• a substituted aromatic heterocycle and the like can be mentioned.
• the ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by R z1 to R z4 may have a substituent.
• R x1 to R x4 may be mutually bonded to form a ring structure.
• R x1 may form a ring structure with any of R x2 to R x4 .
• the ring structure may be an alicyclic hydrocarbon or an aromatic hydrocarbon.
• the alicyclic hydrocarbon formed by two or more of R x1 to R x4 may be polycyclic or monocyclic.
• a monocycloalkane is preferred as the monocyclic alicyclic hydrocarbon.
• Polycycloalkanes are preferred as polycyclic alicyclic hydrocarbons.
• the aromatic hydrocarbon ring formed by two of R x1 to R x4 is benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. and aromatic heterocycles.
• the ring structure (alicyclic hydrocarbon, aromatic hydrocarbon) formed by R x1 to R x4 may have a substituent.
• the ring structure formed by two or more of R x1 to R x4 is preferably an alicyclic hydrocarbon from the viewpoint of acid diffusion controllability.
• R x1 to R x4 , R y1 to R y2 and R z1 to R z4 has an acid anion structure, and the entire organic acid anion portion becomes an n-valent anion.
• n is an integer of 1 or more.
• the organic acid anion moiety represented by the above formula (bd1) is radiation-sensitive to generate an acid acting on the acid-dissociable group in the base resin in the composition by selecting the acid anion structure in the molecule. It functions as a strong acid generator or as an acid diffusion control agent that traps (controls diffusion of acid) the acid generated from the radiation-sensitive strong acid generator upon exposure.
• the acid anion structures possessed by R x1 to R x4 , R y1 to R y2 and R z1 to R z4 include a sulfonate anion structure, a carboxylate anion structure, an imide anion structure, a methide anion structure, a carbanion structure, a borate anion structure, Examples include those having a halogen anion structure, a phosphate anion structure, an antimonate anion structure, an arsenate anion structure, and the like. Among these, those having a sulfonate anion structure and those having a carboxylate anion structure are preferred.
• each of R x1 to R x4 , R y1 to R y2 and R z1 to R z4 may be the above acid anion structure.
• R x1 to R x4 When two or more of R x1 to R x4 are mutually bonded to form a ring structure, a carbon atom forming the ring structure or a hydrogen atom bonded to the carbon atom is substituted with the above acid anion structure. may The same applies to R y1 to R y2 and R z1 to R z4 .
• organic anion moiety represented by the above formula (bd1) examples include, but are not limited to, the following.
• R b1 is a C 17-50 monovalent hydrocarbon group having a steroid skeleton.
• Yb1 is a divalent linking group or a single bond containing a heteroatom.
• V b1 is an alkylene group, a fluorinated alkylene group, or a single bond.
• R fa and R fb are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.
• Z b1 is an acid anion structure.
• Rb1 represents a monovalent hydrocarbon group having 17 to 50 carbon atoms and having a steroid skeleton.
• the steroid skeleton may have a substituent.
• steroid skeleton refers to a ring structure represented by the following chemical formula (St), in which three six-membered rings and one five-membered ring are condensed.
• the number adjacent to the carbon atom indicates the carbon number.
• the carbon numbers shown in the above formula (St) are used.
• the steroid skeleton of the monovalent hydrocarbon group in R b1 preferably has at least one hydroxyl group. That is, in the steroid skeleton of R b1 , at least one hydrogen atom in the ring structure represented by the formula (St) is preferably substituted with a hydroxyl group.
• the number of hydroxyl groups is not particularly limited, and examples include 1 to 10, 1 to 5, 1 to 3, and the like.
• the number of hydroxyl groups is preferably 1 to 3, more preferably 2 or 3, still more preferably 3.
• the steroid skeleton of R b1 may contain a substituent other than a hydroxyl group.
• the position of the alkyl group is not particularly limited, and examples thereof include the 10th, 13th and 17th positions.
• the alkyl groups are preferably present at the 10- and 13-positions.
• the position of the substituent is not particularly limited, and examples thereof include any of the 3-, 7- and 12-positions.
• the substituent is a lactone-containing cyclic group, it may be at the 17-position.
• R b1 has 17 to 50 carbon atoms, preferably 17 to 40 carbon atoms, more preferably 17 to 30 carbon atoms, and particularly preferably 17 to 22 carbon atoms.
• the number of carbon atoms in Rb1 here includes the carbon atoms constituting the steroid skeleton and the carbon atoms in the substituents bonded to the steroid skeleton.
• R b1 is preferably a group represented by the following formulas (R b1 -1) to (R b1 -3). When enantiomers and diastereomers exist, the following formula represents those stereoisomers and includes them.
• R S11 , R S12 and R S13 each independently represent a hydrogen atom, a hydroxyl group, or a heteroatom-containing substituent other than a hydroxyl group.
• R s21 and R s22 are each independently a hydrogen atom, a hydroxyl group, or a heteroatom-containing substituent other than a hydroxyl group.
• R S23 represents an alkyl group which may contain a heteroatom.
• R S31 , R S32 and R S33 each independently represent a hydrogen atom, a hydroxyl group, or a heteroatom-containing substituent other than a hydroxyl group.
• R S34 represents a lactone-containing cyclic group. * represents a bond that binds to Y b1 in formula (b1). ]
• substituents other than a hydroxyl group containing a heteroatom in R S21 and R S22 include a hydroxyl group containing a heteroatom in R S31 to R S33 in the formula (R b1 -3).
• R S11 to R S13 is preferably a hydroxyl group, and two or more of R S11 to R S13 are preferably hydroxyl groups . are all hydroxyl groups. Among R S11 to R S13 , those that are not hydroxyl groups are preferably hydrogen atoms.
• R s21 and R s22 are preferably a hydroxyl group, and both R s21 and R s22 are preferably hydroxyl groups. Of R 21 and R 22 , those that are not hydroxyl groups are preferably hydrogen atoms.
• R S23 represents an alkyl group which may contain a heteroatom. The alkyl group may be linear or branched. As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable.
• R S31 to R S13 is preferably a hydroxyl group
• two or more of R S31 to R S33 are preferably hydroxyl groups
• R S3 to R More preferably, all of S33 are hydroxyl groups.
• those that are not hydroxyl groups are preferably hydrogen atoms.
• R b1 is more preferably a group represented by formula (R b1 -1).
• R b1 Specific examples of R b1 are shown below, but are not limited thereto.
• * indicates a bond that bonds to Y b1 in formula (b1).
• R b1 is preferably represented by formulas (Rb-1-1) to (Rb-1-19), and more preferably represented by formulas (Rb-1-1) to (Rb-1-7).
• R fa and R fb are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms.
• Yb1 represents a heteroatom-containing divalent linking group or a single bond.
• Examples of the heteroatom-containing divalent linking group for Yb1 include the same as those exemplified for the heteroatom-containing divalent linking group for Y1 in the above formula ( 1 ).
• Yb1 is preferably a divalent linking group containing an ester bond or an ether bond.
• Vb1 represents an alkylene group, a fluorinated alkylene group, or a single bond.
• the alkylene group or fluorinated alkylene group for V b1 may be linear or branched, but is preferably linear.
• the alkylene group or fluorinated alkylene group for V b1 preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms.
• the acid anion structures of R x1 to R x4 , R y1 to R y2 and R z1 to R z4 in the above formula (bd1) can be preferably employed.
• organic acid anion moiety represented by formula (b1) are listed below, but are not limited to these specific examples.
• k and k' each independently represent an integer of 0 to 5, and k'' represents an integer of 1 to 5.
• a structure in which the sulfonate anion is replaced with a carboxylate anion can also be preferably employed.
• fluorine atoms may not be bonded to the carbon atoms at the ⁇ - and ⁇ -positions of the carboxylate anion.
• the organic acid anion moiety represented by the above formula (b1) is preferably represented by the following formula (b1-an1). Although the organic acid anion moiety having a sulfonate anion is shown below, a structure in which the sulfonate anion is replaced with a carboxylate anion can also be preferably employed. When the organic acid anion moiety has a carboxylate anion, fluorine atoms may not be bonded to the carbon atoms at the ⁇ - and ⁇ -positions of the carboxylate anion.
• R S11 to R S13 are the same as in the general formula (R b1 -1).
• V b11 represents a single bond, —CHF— or —CF 2 —.
• k represents an integer of 1 to 5; ]
• R S11 to R S13 are the same as in general formula (R b1 -1).
• 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 onium salt, the base resin (at least one of the radiation-sensitive acid-generating resin and the resin), and optional additives.
• solvents examples include alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, and hydrocarbon-based solvents.
• alcohol 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 Monoalcoholic solvents of numbers 1 to 18; C2-C18 poly(ethylene glycol, 1,2-propylene glycol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, etc.) a alcohol-based solvent; A polyhydric alcohol partial ether solvent obtained by etherifying a part of the hydroxy groups of the above polyhydric alcohol solvent may be used.
• ether solvents examples 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 (methylphenyl ether); Examples thereof include polyhydric alcohol ether solvents obtained by etherifying the hydroxy groups of the above polyhydric alcohol solvents.
• ketone solvents include linear ketone solvents such as acetone, butanone, and methyl-iso-butyl ketone: Cyclic ketone solvents such as cyclopentanone, cyclohexanone, and methylcyclohexanone: 2,4-pentanedione, acetonylacetone, acetophenone and the like.
• 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, N-methylpropionamide, and the like.
• ester solvents include monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate; 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; Polyvalent carboxylic acid diester solvents such as propylene glycol diacetate, methoxytriglycol acetate, diethyl oxalate, ethyl acetoacetate, ethyl lactate and diethyl phthalate can be used.
• monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate
• hydrocarbon solvents examples include aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane; Aromatic hydrocarbon solvents such as benzene, toluene, di-iso-propylbenzene, n-amylnaphthalene, and the like are included.
• alcohol-based solvents examples include butanol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, benzyl alcohol, and cyclohexanone-based solvents are preferred. More preferred are diacetone alcohol, propylene glycol monomethyl ether acetate, ethyl lactate, cyclohexanone, and ⁇ -butyrolactone.
• the radiation-sensitive resin composition may contain one or more solvents.
• the radiation-sensitive resin composition may contain other optional components in addition to the components described above.
• the other optional components include a cross-linking agent, an 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 comprises, for example, an onium salt, a base resin (at least one of a radiation-sensitive acid-generating resin and a resin), a solvent, and, if necessary, other optional components in a predetermined ratio. It can be prepared by mixing. After mixing, the radiation-sensitive resin composition is preferably filtered through, for example, a filter having a pore size of about 0.05 ⁇ m to 0.2 ⁇ m.
• the solid content concentration of the radiation-sensitive resin composition is usually 0.1% by mass to 50% by mass, preferably 0.5% by mass to 30% by mass, more preferably 1% by mass to 20% by mass.
• the pattern formation method in this embodiment includes: Step (1) of directly or indirectly coating the radiation-sensitive resin composition on a substrate to form a resist film (hereinafter also referred to as “resist film forming step”); Step (2) of exposing the resist film (hereinafter also referred to as “exposure step”), and A step (3) of developing the exposed resist film (hereinafter also referred to as a “development step”) is included.
• a high-quality resist pattern can be formed because the radiation-sensitive resin composition is excellent in sensitivity and CDU performance in the exposure process and excellent in suppressing development residue in the development process. can be done.
• Each step will be described below.
• a resist film is formed from the radiation-sensitive resin composition.
• the substrate on which the resist film is formed include conventionally known substrates such as silicon wafers, silicon dioxide, and aluminum-coated wafers. Further, for example, an organic or inorganic antireflection film disclosed in JP-B-6-12452, JP-A-59-93448, etc. may be formed on the substrate. Examples of coating methods include spin coating, casting coating, and roll coating. After coating, if necessary, prebaking (PB) may be performed in order to volatilize the solvent in the coating film.
• the PB temperature is usually 60°C to 140°C, preferably 80°C to 120°C.
• the PB time is usually 5 to 600 seconds, preferably 10 to 300 seconds.
• the thickness of the resist film to be formed is preferably 10 nm to 1,000 nm, more preferably 10 nm to 500 nm.
• an immersion protective film that is insoluble in the immersion liquid may be provided.
• a solvent peelable protective film that is peeled off with a solvent before the development process see, for example, JP-A-2006-227632
• a developer peelable protective film that is peeled off at the same time as development in the development process For example, see WO2005-069076 and WO2006-035790
• a resin having the structural units (I) to (IV) and, if necessary, the structural unit (V) as the base resin in the composition is preferably used.
• the resist film formed in the resist film forming step (step (1) above) is coated through a photomask (in some cases, through an immersion medium such as water). , emit radiation and expose. Radiation used for exposure depends on the line width of the desired pattern. A charged particle beam and the like can be mentioned. Among these, far ultraviolet rays, electron beams, and EUV are preferred, and ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), electron beams, and EUV are more preferred. The following electron beams and EUV are more preferable.
• immersion liquid used examples include water and fluorine-based inert liquids.
• a post-exposure bake is performed to accelerate the dissociation of the acid-dissociable groups of the resin or the like by the acid generated from the radiation-sensitive acid generator upon exposure in the exposed portions of the resist film.
• This PEB causes a difference in solubility in a 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 to 600 seconds, preferably 10 to 300 seconds.
• step (3) above the resist film exposed in the exposure step (step (2) above) 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
• TMAH tetramethylammonium hydroxide
• a TMAH aqueous solution is preferable, and a 2.38% by mass TMAH aqueous solution is more preferable.
• organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, alcohol solvents, or solvents containing organic solvents can be used.
• organic solvent include one or more of the solvents listed above as the solvent for the radiation-sensitive resin composition.
• ester solvents and ketone solvents are preferred.
• the ester solvent an acetate solvent is preferable, and n-butyl acetate and amyl acetate are more preferable.
• the ketone-based solvent a chain ketone is preferable, and 2-heptanone is more preferable.
• the content of the organic solvent in the developer is preferably 80% by mass or more, more preferably 90% by mass or more, still 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 and silicon oil.
• Examples of the developing method include a method of immersing the substrate in a tank filled with a developer for a certain period of time (dip method), and a method of developing by standing still for a certain period of time while the developer is heaped up on the surface of the substrate by surface tension (puddle method).
• dip method a method of immersing the substrate in a tank filled with a developer for a certain period of time
• puddle method a method of developing by standing still for a certain period of time while the developer is heaped up on the surface of the substrate by surface tension
• spray method a method in which the developer is sprayed onto the surface of the substrate
• dynamic dispensing method a method in which the developer is continuously applied while scanning the developer dispensing nozzle at a constant speed on the substrate rotating at a constant speed
• Mw and Mn of the polymer are determined by gel permeation chromatography (GPC) using Tosoh GPC columns (2 "G2000HXL”, 1 "G3000HXL”, 1 "G4000HXL”) under the following conditions: It was measured.
• Eluent Tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.)
• Flow rate 1.0 mL/min
• Sample concentration 1.0% by mass
• Sample injection volume 100 ⁇ L
• a radiation-sensitive resin composition was prepared by filtering a solution obtained by dissolving each component with the composition shown in Table 1 in a solvent in which 100 ppm of FC-4430 manufactured by 3M was dissolved as a surfactant and filtered through a 0.2 ⁇ m size filter. was prepared.
• each component is as follows.
• Organic solvent PGMEA (propylene glycol monomethyl ether acetate)
• GBL ⁇ -butyrolactone
• CHN cyclohexanone
• PGME propylene glycol monomethyl ether
• DAA diacetone alcohol
• EL ethyl lactate
• This resist film was scanned with an EUV scanner ("NXE3300" by ASML (NA 0.33, ⁇ 0.9/0.6, quadruple pole illumination, pitch 46 nm on wafer, +20% bias hole pattern mask)). was exposed using PEB was performed on a hot plate at 120° C. for 60 seconds, and development was performed with a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to form a resist pattern with 23 nm holes and a 46 nm pitch.
• TMAH tetramethylammonium hydroxide
• the exposure dose for forming the resist pattern of 23 nm holes with a pitch of 46 nm was defined as the optimum exposure dose (Eop), and the optimum exposure dose was defined as the sensitivity (mJ/cm 2 ).
• a wafer having a resist film formed thereon was prepared by performing the same operations as above up to the operation of forming a resist film having an average thickness of 55 nm.
• PEB was performed for 60 seconds on a hot plate at 120° C. without performing pattern exposure using an EUV scanner. Then, it was developed with a 2.38% by mass TMAH aqueous solution for 30 seconds, rinsed with pure water for 30 seconds, and dried. Thus, a wafer for evaluation of development residue was produced.
• the radiation-sensitive resin composition of the example was excellent in sensitivity, CDU performance and development residue.
• a resist pattern having good sensitivity to exposure light and excellent CDU performance and development residue suppressing property can be formed. Therefore, these materials can be suitably used in processing processes of semiconductor devices, which are expected to further miniaturize in the future.

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