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
  • G03F7/20—Exposure; Apparatus therefor
  • G03F7/2051—Exposure without an original mask, e.g. using a programmed deflection of a point source, by scanning, by drawing with a light beam, using an addressed light or corpuscular source
  • G03F7/2059—Exposure without an original mask, e.g. using a programmed deflection of a point source, by scanning, by drawing with a light beam, using an addressed light or corpuscular source using a scanning corpuscular radiation beam, e.g. an electron beam
• • 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
  • G03F7/039—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
  • G03F7/004—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
• • 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

Definitions

• the present invention relates to a radiation-sensitive resin composition, a pattern forming method, a radiation-sensitive acid generator, and an acid diffusion control agent.
• 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 solvent developer.
• the above photolithography technology promotes pattern refinement by using short wavelength radiation such as ArF excimer laser or by combining this radiation with liquid immersion exposure method (liquid immersion lithography).
• short wavelength radiation such as ArF excimer laser
• liquid immersion exposure method liquid immersion lithography
• efforts are being made to utilize even shorter wavelength radiation such as electron beams, X-rays, and EUV (extreme ultraviolet), and resist materials containing acid generators with benzene rings that increase the absorption efficiency of such radiation is also being considered.
• EUV extreme ultraviolet
• next-generation technology is also required to have resist performance equivalent to or higher than conventional resists in terms of sensitivity, LWR performance, which is an index of line width uniformity, and process window width.
• the present invention provides a radiation-sensitive resin composition, a pattern forming method, a radiation-sensitive acid generator, and an acid-sensitive resin composition that can exhibit sensitivity, LWR performance, and process window at a sufficient level when next-generation technology is applied.
• the purpose is to provide a diffusion control agent.
• the present invention provides: A resin containing a repeating unit A having an acid-dissociable group; an onium salt containing an organic acid anion moiety and an onium cation moiety; Contains solvent and
• the onium salt relates to a radiation-sensitive resin composition containing at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group.
• the radiation-sensitive resin composition it is possible to construct a resist film that satisfies sensitivity, LWR performance, and process window. Although the reason for this is not certain, it is inferred as follows.
• the absorption of radiation such as EUV having a wavelength of 13.5 nm by fluorine atoms is very large, and this makes the radiation-sensitive resin composition highly sensitive.
• the acid dissociable group included in the structural unit A in the resin has high acid dissociation efficiency upon exposure, the contrast between exposed areas and unexposed areas increases, and excellent pattern formation properties are exhibited. It is presumed that the above resist performance can be achieved through these combined effects.
• 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 above-mentioned radiation-sensitive resin composition that is excellent in sensitivity, LWR performance, and process window, a high-quality resist pattern can be efficiently formed.
• the present invention provides, in another embodiment, an onium salt containing an organic acid anion moiety and an onium cation moiety;
• the above onium salt relates to a compound containing at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group.
• the present invention provides: an onium salt containing an organic acid anion moiety and an onium cation moiety;
• the above onium salt relates to a radiation-sensitive acid generator containing a compound containing at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group.
• the present invention provides: an onium salt containing an organic acid anion moiety and an onium cation moiety;
• the onium salt relates to an acid diffusion control agent containing a compound containing at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group.
• the radiation-sensitive resin composition (hereinafter also simply referred to as "composition") according to the present embodiment includes a radiation-sensitive resin 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, LWR performance, and process window to the resulting resist film.
• the resin is a polymer aggregate (G1) containing repeating units A having acid-dissociable groups (hereinafter, the polymer (G1) is also referred to as "base resin").
• the base resin includes a repeating unit B containing an organic acid anion moiety and an onium cation moiety, a structural unit D having a phenolic hydroxyl group, a structural unit E containing a lactone structure, etc., and other structural units. Good too.
• Each structural unit will be explained below.
• repeating unit A (hereinafter also referred to as "structural unit A") is preferably a repeating unit represented by the following formula (1).
• R T is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• R X is a monovalent hydrocarbon group having 1 to 20 carbon atoms. Cy represents an alicyclic structure having 3 to 20 ring members formed together with the carbon atom to which it is bonded.
• Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the like.
• the above-mentioned chain hydrocarbon group having 1 to 10 carbon atoms is, for example, a straight chain or branched saturated hydrocarbon group having 1 to 10 carbon atoms, or a straight chain or branched unsaturated hydrocarbon group having 1 to 10 carbon atoms. can be given.
• Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms include a monocyclic or polycyclic saturated hydrocarbon group, or a monocyclic or polycyclic unsaturated hydrocarbon group.
• a monocyclic saturated hydrocarbon group a cyclopentyl 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.
• 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 bond chain 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 bond chain 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.
• R X is preferably a linear or branched saturated hydrocarbon group having 1 to 5 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
• the alicyclic structure having 3 to 20 ring members in Cy is not particularly limited as long as it has an alicyclic structure, and may have a monocyclic, bicyclic, tricyclic, tetracyclic or more polycyclic structure. It may be a bridged ring structure, a spiro ring structure, a ring assembly structure in which a plurality of rings are directly bonded with a single bond or double bond, or a combination thereof.
• a monocyclic, bicyclic, tricyclic, or tetracyclic bridged ring structure such as cyclopentane, cyclohexane, norbornane, adamantane, tricyclo[5.2.1.02,6]decane. , tetracyclo[4.4.0.12,5.17,10]dodecane, perhydronaphthalene, or perhydroanthracene, or a derivative thereof.
• the repeating unit represented by the above formula (1) is preferably represented by the following formulas (A-1) to (A-8), for example.
• RT and RX have the same meanings as in the above formula (1).
• structural unit A is preferably represented by, for example, the above formulas (A-1), (A-4), (A-5), (A-6), and (A-8).
• the structural unit A is a repeating unit represented by the following formula (1-2).
• R c is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• Lc is a single bond or a divalent linking group.
• R c1 , R c2 and R c3 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.
• R c is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerizability of the monomer that provides the structural unit represented by formula (1-2).
• Examples of the divalent linking group represented by L c include alkanediyl group, cycloalkanediyl group, alkenediyl group, -OR LA -*, -COOR LB -*, etc. (* indicates the carbonyl group side (represents a bond).
• the above alkanediyl group is preferably an alkanediyl group having 1 to 8 carbon atoms.
• Examples of the above-mentioned cycloalkanediyl group include monocyclic cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group; polycyclic cycloalkanediyl groups such as norbornanediyl group and adamantanediyl group.
• the above-mentioned cycloalkanediyl group is preferably a cycloalkanediyl group having 5 to 12 carbon atoms.
• alkenediyl group examples include ethenediyl group, propenediyl group, butenediyl group, and the like.
• the alkenediyl group mentioned above is preferably an alkenediyl group having 2 to 6 carbon atoms.
• R LA in the above -OR LA -* examples include the above alkanediyl group, the above cycloalkanediyl group, the above alkenediyl group, and the like.
• R LB in the above -COOR LB -* examples include the above alkanediyl group, the above cycloalkanediyl group, the above alkenediyl group, and arenediyl group.
• the arenediyl group include a benzenediyl group, tolylene group, and naphthalenediyl group.
• the arenediyl group is preferably an arenediyl group having 6 to 15 carbon atoms.
• L c is preferably a single bond or -COOR LB -*.
• RLB is preferably an alkanediyl group.
• halogen atoms such as fluorine atoms and chlorine atoms
• halogenated alkyl groups such as trifluoromethyl groups
• alkoxy groups such as methoxy groups, cyano groups, etc.
• the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R c1 , R c2 and R c3 includes the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by RX in the above formula (1).
• R c1 and R c2 are each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms
• R c3 is a monovalent alicyclic or aromatic hydrocarbon group having 6 to 12 carbon atoms.
• a hydrogen group is preferred.
• the repeating unit represented by formula (1-2) is preferably represented by the following formulas (2-1) to (2-18).
• Rc has the same meaning as in the above formula (2).
• those represented by the above formulas (2-1) to (2-3) and (2-10) to (2-12) are preferable.
• the content ratio of structural unit A in the resin (total if there are multiple types of structural unit A) is preferably 10 mol% or more, more preferably 20 mol% or more, based on all structural units constituting the resin. , more preferably 30 mol% or more.
• the content ratio is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less.
• Repeating unit B (hereinafter also referred to as "structural unit B") is a repeating unit containing an organic acid anion moiety and an onium cation moiety.
• structural unit B is a repeating unit containing an organic acid anion moiety and an onium cation moiety.
• the resin containing structural unit B is also referred to as "radiation-sensitive acid-generating resin.”
• the above structural unit B is a repeating unit derived from a monomer containing a structure that decomposes upon exposure and generates an acid. Therefore, the resin containing structural unit B functions as a radiation-sensitive acid-generating resin.
• the onium cation moiety in structural unit B include sulfonium cations and iodonium cations.
• the onium cation moiety in the above structural unit B is preferably a sulfonium cation, and the monomer providing such a structural unit B is, for example, a monomer represented by the following formula (2) or a monomer represented by the formula (3). It is preferable that the repeating unit is derived from a monomer.
• R A and R B are a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• R Y and R Z are independently a hydrogen atom, a fluorine atom, or a fluorinated hydrocarbon group, and at least one is a fluorine atom or a fluorinated hydrocarbon group.
• a plurality of R Y and R Z may be the same or different.
• n 11 is an integer from 1 to 20.
• R 1T to R 3T are independently monovalent hydrocarbon groups.
• R 4T to R 6T are independently monovalent hydrocarbon groups.
• Y 11 is a divalent hydrocarbon group having 1 to 20 carbon atoms that may contain a heteroatom.
• Y 21 is an alkanediyl group having 1 to 6 carbon atoms, an alkenediyl group having 2 to 6 carbon atoms, or a phenylene group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxy group.
• the alkanediyl group having 1 to 6 carbon atoms, the alkenediyl group having 2 to 6 carbon atoms, and the phenylene group may be substituted with a fluorine atom.
• R Y and R Z are independently a hydrogen atom, a fluorine atom, or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, and at least one of them is a fluorine atom. It is an atom or a fluorinated hydrocarbon group.
• the hydrocarbon group constituting the monovalent fluorinated hydrocarbon group may be linear, branched, or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, Alkyl groups such as n-butyl group and tert-butyl group; cycloalkyl groups such as cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, adamantyl group; Alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, cyclohexenyl group; Aryl group such as phenyl group, naphthyl group, thienyl group; benzyl group, 1-phenylethyl group, 2-phenylethyl group Examples
• Examples of the group include, but are not limited to, those shown below.
• the hydrogen atoms contained in the structures shown below may be substituted with substituents containing heteroatoms, such as halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), carboxy groups, etc. , hydroxyl group, thiol group, amino group, etc.
• organic acid anion moiety of the monomer providing structural unit B examples include, but are not limited to, those shown below. All of the following are organic acid anion moieties that have an iodine-substituted aromatic ring structure, but as organic acid anion moieties that do not have an iodine-substituted aromatic ring structure, the iodine atom in the formula below can be replaced with a hydrogen atom or other A structure in which the iodine atom is substituted with an atom or group other than the iodine atom, such as a substituent group, can be suitably employed.
• R 1T to R 3T are independently monovalent hydrocarbon groups
• R 4T to R 6T are independently monovalent hydrocarbon groups.
• At least one of the monovalent hydrocarbon groups in R 1T to R 3T is preferably an aromatic ring having a fluorine atom
• at least one of the monovalent hydrocarbon groups in R 4T to R 6T is preferably an aromatic ring having a fluorine atom.
• it is an aromatic ring containing a fluorine atom.
• aromatic ring having a fluorine atom refers to a group in which some or all of the hydrogen atoms contained in the aromatic ring are fluorine atoms, a fluorinated hydrocarbon group (preferably a perfluorohydrocarbon group), or a pentafluorosulfanyl group. refers to a structure substituted with a group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group.
• the above-mentioned monovalent hydrocarbon group may be linear, branched, or cyclic, and specific examples include the same hydrocarbon groups that constitute the fluorinated hydrocarbon groups in RY and RZ.
• an aryl group is preferable.
• some of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom.
• a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom.
• Any two or more of R 1T to R 3T may be bonded to each other to form a ring with the sulfur atom to which they are bonded, and any two or more of R 4T to R 6T may be bonded to each other. These may form a ring together with the sulfur atom to which they are bonded.
• the onium cation moiety in formula (2) and formula (3) is preferably represented by the following formula (Q-1).
• Ra 1 and Ra 2 each independently represent a substituent.
• n 1 represents an integer from 0 to 5, and when n 1 is 2 or more, a plurality of Ra 1s may be the same or different.
• n 2 represents an integer from 0 to 5, and when n 2 is 2 or more, a plurality of Ra 2 may be the same or different.
• n 3 represents an integer from 1 to 5, and when n 3 is 2 or more, a plurality of Ra 3s may be the same or different.
• Ra 3 represents a substituent.
• Ra 1 and Ra 2 may be linked to each other to form a ring. When n 1 is 2 or more, a plurality of Ra 1 may be connected to each other to form a ring.
• n 2 When n 2 is 2 or more, a plurality of Ra 2 may be connected to each other to form a ring.
• Ra 1 and Ra 2 When n 1 is 1 or more and n 2 is 1 or more, Ra 1 and Ra 2 may be connected to each other to form a ring (ie, a heterocycle containing a sulfur atom).
• Substituents represented by Ra 1 and Ra 2 include alkyl groups, cycloalkyl groups, alkoxy groups, cycloalkyloxy groups, alkoxycarbonyl groups, alkylsulfonyl groups, hydroxyl groups, halogen atoms, halogenated hydrocarbon groups, pentafluoro A sulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group are preferred.
• the alkyl groups of Ra 1 and Ra 2 may be linear or branched.
• This alkyl group preferably has 1 to 10 carbon atoms, and includes, for example, those similar to those listed as the hydrocarbon group constituting the fluorinated hydrocarbon group in R Y and R Z.
• methyl group, ethyl group, n-butyl group and t-butyl group are particularly preferred.
• Examples of the cycloalkyl group for Ra 1 and Ra 2 include monocyclic or polycyclic cycloalkyl groups (preferably cycloalkyl groups having 3 to 20 carbon atoms), such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclo Mention may be made of heptyl, cyclooctyl, cyclododecanyl, cyclopentenyl, cyclohexenyl and cyclooctadienyl groups. Among these, cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl groups are particularly preferred.
• alkyl group portion of the alkoxy group of Ra 1 and Ra 2 examples include those listed above as the alkyl group of Ra 1 and Ra 2 .
• alkoxy group methoxy, ethoxy, n-propoxy and n-butoxy groups are particularly preferred.
• Examples of the cycloalkyl group portion of the cycloalkyloxy group of Ra 1 and Ra 2 include those listed above as the cycloalkyl group of Ra 1 and Ra 2 .
• As the cycloalkyloxy group a cyclopentyloxy group and a cyclohexyloxy group are particularly preferred.
• alkoxy group portion of the alkoxycarbonyl group of Ra 1 and Ra 2 examples include those listed above as the alkoxy group of Ra 1 and Ra 2 .
• alkoxycarbonyl group methoxycarbonyl group, ethoxycarbonyl group and n-butoxycarbonyl group are particularly preferred.
• Examples of the alkyl group portion of the alkylsulfonyl group of Ra 1 and Ra 2 include those listed above as the alkyl group of Ra 1 and Ra 2 . Further, examples of the cycloalkyl group moiety of the cycloalkylsulfonyl group of Ra 1 and Ra 2 include those listed above as the cycloalkyl group of Ra 1 and Ra 2 .
• alkylsulfonyl group or cycloalkylsulfonyl group methanesulfonyl group, ethanesulfonyl group, n-propanesulfonyl group, n-butanesulfonyl group, cyclopentanesulfonyl group and cyclohexanesulfonyl group are particularly preferred.
• Each of Ra 1 and Ra 2 may further have a substituent.
• substituents include a halogen atom such as a fluorine atom (preferably a fluorine atom), a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkoxy group, a cycloalkyloxy group, an alkoxyalkyl group, and a cycloalkyloxyalkyl group. , an alkoxycarbonyl group, a cycloalkyloxycarbonyl group, an alkoxycarbonyloxy group, and a cycloalkyloxycarbonyloxy group.
• halogen atom for Ra 1 and Ra 2 examples include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred.
• the halogenated hydrocarbon groups for Ra 1 and Ra 2 are preferably halogenated alkyl groups.
• alkyl group and halogen atom constituting the halogenated alkyl group include those mentioned above. Among them, fluorinated alkyl groups are preferred, and CF3 is more preferred.
• Ra 1 and Ra 2 may be linked to each other to form a ring (ie, a heterocycle containing a sulfur atom).
• the divalent linking group include -COO-, -OCO-, -CO-, -O-, -S-, -SO-, -SO 2 -, alkylene group, cycloalkylene group, alkenylene group, or these groups. Examples include combinations of two or more of the following, and those having a total carbon number of 20 or less are preferred.
• Ra 1 and Ra 2 are bonded to each other to form a ring
• Ra 1 and Ra 2 are bonded to each other to form -COO-, -OCO-, -CO-, -O-, -S-, -SO- , -SO2- or a single bond
• forming -O-, -S- or a single bond is more preferable, and forming a single bond is particularly preferable.
• n 1 is 2 or more, a plurality of Ra 1s may be connected to each other to form a ring
• n 2 is 2 or more
• a plurality of Ra 2s may be connected to each other to form a ring.
• Such an example includes, for example, an embodiment in which two Ra 1s are linked to each other and form a naphthalene ring together with the benzene ring to which they are bonded.
• Examples of the substituent represented by Ra 3 include an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkyloxy group, an alkoxycarbonyl group, an alkylsulfonyl group, a hydroxyl group, a halogen atom, a halogenated hydrocarbon group, a pentafluorosulfanyl group, A pentafluorosulfanyloxy group and a pentafluorosulfanylthio group are preferred.
• At least one Ra 3 is preferably a fluorine atom or a group having one or more fluorine atoms, and at least one Ra 3 is a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanyloxy group.
• a fluorosulfanylthio group is more preferred.
• groups having a fluorine atom include groups in which an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkyloxy group, an alkoxycarbonyl group, and an alkylsulfonyl group as Ra 1 and Ra 2 are substituted with a fluorine atom. .
• fluorinated alkyl groups can be preferably mentioned, such as 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 , C 8 F 17 , CH2CF3 , CH2CH2CF3 , CH2C2F5 , CH2CH2C2F5 , CH2C3F7 , CH2CH2C3F7 , CH2C4F _ _ _ _ _ _ _ _ 9 and CH 2 CH 2 C 4 F 9 can be more preferably mentioned, and CF 3 can be particularly preferably mentioned.
• Ra 3 is preferably a fluorine atom, CF 3 , a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group.
• n 1 and n 2 are each independently preferably an integer of 0 to 3, preferably an integer of 0 to 2.
• n 3 is preferably an integer of 1 to 3, more preferably 1 or 2.
• n 1 +n 2 +n 3 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.
• onium cation moiety in structural unit B a diaryliodonium cation is also preferred.
• diaryliodonium cations include the following. All of the following are iodonium cation moieties that include an aromatic ring structure with a fluorine atom, but there are structures in which the fluorine atom is replaced with a fluorinated hydrocarbon group such as a trifluoromethyl group, and structures in which the fluorine atom is replaced with a hydrogen atom. A structure substituted with can also be suitably employed.
• the content ratio of the structural unit B in the resin is preferably 2 mol% or more, more preferably 3 mol% or more, based on all the structural units constituting the resin. , more preferably 4 mol% or more, particularly preferably 5 mol% or more. Further, it is preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less, and particularly preferably 15 mol% or less.
• the repeating unit D (hereinafter also referred to as "structural unit D") is a structural unit having a phenolic hydroxyl group.
• the present invention also includes, as the phenolic hydroxyl group of the structural unit D, a phenolic hydroxyl group that is generated by deprotection due to the action of an acid generated by exposure.
• the resin contains the structural unit D, the solubility in the developer can be adjusted more appropriately, and as a result, the sensitivity etc. of the radiation-sensitive resin composition can be further improved.
• the structural unit D is used to improve etching resistance and to increase the distance between exposed and unexposed areas. Contributes to improving the difference in developer solubility (dissolution contrast). 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 structural unit D is preferably a repeating unit represented by the following formula (D).
• 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 a plurality of R 101s exist, the plurality of R 101s are the same or different from each other.
• R 102 is a cyano group, a nitro group, an alkyl group, a fluorinated alkyl group, an alkoxycarbonyloxy group, an acyl group, or an acyloxy group.
• n d3 is an integer from 0 to 2
• m 3d is an integer from 1 to 8
• m d4 is an integer from 1 to 8.
• 1 ⁇ m d3 +m d4 ⁇ 2n d3 +5 is satisfied.
• R ⁇ is preferably a hydrogen atom or a methyl group.
• LCA a single bond or -COO-* is preferable.
• Examples of the protecting group that can be deprotected by the action of an acid represented by R 101 include groups represented by the following formulas (AL-1) to (AL-3).
• R M1 and R M2 are monovalent hydrocarbon groups containing heteroatoms such as oxygen atom, sulfur atom, nitrogen atom, and fluorine atom. Good too.
• the monovalent hydrocarbon group may be linear, branched, or cyclic, preferably an alkyl group having 1 to 40 carbon atoms, and more preferably an alkyl group having 1 to 20 carbon atoms.
• a is an integer of 0 to 10, preferably an integer of 1 to 5.
• * is a bond to another moiety.
• R M3 and R M4 each independently represent a hydrogen atom or a monovalent hydrocarbon group, and include a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. It's okay to stay.
• the monovalent hydrocarbon group may be linear, branched, or cyclic, and is preferably an alkyl group having 1 to 20 carbon atoms.
• any two of R M2 , R M3 and R M4 may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded or the carbon atom and oxygen atom.
• a ring having 4 to 16 carbon atoms is preferable, and an alicyclic ring is particularly preferable.
• R M5 , R M6 and R M7 each independently represent a monovalent hydrocarbon group, and contain a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. You can stay there.
• the monovalent hydrocarbon group may be linear, branched, or cyclic, and is preferably an alkyl group having 1 to 20 carbon atoms. Further, any two of R M5 , R M6 and R M7 may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
• a ring having 5 to 16 carbon atoms is preferable, and an alicyclic ring is particularly preferable.
• the group represented by the above formula (AL-3) is preferable as the protecting group that is deprotected by the action of an acid.
• Examples of the alkyl group for R 102 include straight-chain or branched alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, and propyl groups.
• Examples of the fluorinated alkyl group include linear or branched fluorinated alkyl groups having 1 to 8 carbon atoms, such as a trifluoromethyl group and a pentafluoroethyl group.
• Examples of the alkoxycarbonyloxy group include linear or alicyclic alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as a methoxycarbonyloxy group, a butoxycarbonyloxy group, and an adamantylmethyloxycarbonyloxy group.
• acyl group examples include aliphatic or aromatic acyl groups having 2 to 12 carbon atoms, such as an acetyl group, a propionyl group, a benzoyl group, and an acryloyl group.
• acyloxy group examples include aliphatic or aromatic acyloxy groups having 2 to 12 carbon atoms, such as an acetyloxy group, a propionyloxy group, a benzoyloxy group, and an acryloyloxy group.
• n d3 is more preferably 0 or 1, and even more preferably 0.
• m d3 is preferably an integer of 1 to 3, more preferably 1 or 2.
• m d4 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2.
• the above structural unit D is a structural unit represented by the following formulas (D-1) to (D-10) (hereinafter also referred to as “structural unit (D-1) to structural unit (D-10)"). etc. is preferable.
• R ⁇ is the same as in the above formula (D).
• the content ratio of the structural unit D (total when there are multiple types of structural units D) is preferably 5 mol% or more, more preferably 8 mol% or more, and 10 mol% based on the total structural units constituting the resin. % or more is more preferable, and 15 mol% or more is particularly preferable.
• the content ratio is preferably 60 mol% or less, more preferably 50 mol% or less, and even more preferably 40 mol% or less.
• the structural unit E is a structural unit containing at least one type selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure.
• the base resin can adjust its solubility in a developer, and as a result, the radiation-sensitive resin composition can improve lithography performance such as resolution. can. Furthermore, the adhesion between the resist pattern formed from the base resin and the substrate can be improved.
• the content ratio of the structural unit E is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, based on all the structural units constituting the base resin.
• the content ratio is preferably 60 mol% or less, more preferably 50 mol% or less, and even more preferably 40 mol% or less.
• the base resin of the present invention may contain structural units other than structural units A, B, D, and E.
• Such other structural units include structural units having aliphatic hydrocarbon groups such as alkyl (meth)acrylates (excluding structural unit A); fatty acids such as cycloalkyl (meth)acrylates and adamantyl (meth)acrylates; Structural units having a cyclic hydrocarbon group (excluding structural unit A); Structural units having an aromatic hydrocarbon group such as styrene, phenyl (meth)acrylate, iodostyrene, etc. can be mentioned.
• the base resin of the present invention preferably contains an iodine-substituted aromatic ring structure.
• the iodine-substituted aromatic ring structure that the base resin has is preferably contained in structural units A, B, D, E, or other structural units other than A to E, and preferably contained in structural units B, D, or A to E. It is more preferable that it is contained in a structural unit other than E.
• the content ratio of the iodine-substituted aromatic ring structure is preferably 1 mol% or more, more preferably 2 mol% or more, and even more preferably 3 mol% or more, based on the total structural units constituting the base resin.
• the content ratio is preferably 30 mol% or less, more preferably 25 mol% or less, and even more preferably 20 mol% or less.
• the resin serving as the base resin can be synthesized, for example, by carrying out a polymerization reaction of monomers providing each structural unit in an appropriate solvent using a known radical polymerization initiator.
• the molecular weight of the base resin is not particularly limited, but the polystyrene equivalent weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is preferably 1,000 or more, more preferably 2,000 or more, and 3,000 or more. More preferably, it is 4,000 or more. Further, it is preferably 50,000 or less, more preferably 30,000 or less, even more preferably 15,000 or less, and particularly preferably 12,000 or less. If the Mw of the resin is within the above range, the resulting resist film will have good heat resistance and developability.
• Mw polystyrene equivalent weight average molecular weight determined by gel permeation chromatography
• 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.
• GPC columns 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (all manufactured by Tosoh) Column temperature: 40°C Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL/min Sample concentration: 1.0 mass% Sample injection volume: 100 ⁇ L Detector: Differential refractometer Standard material: Monodisperse polystyrene
• the content of the resin is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% 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 state of the resist film surface and the components in the resist film can be changed. The distribution can be controlled to a desired state.
• the high fluorine content resin may, for example, have one or more of the structural units A to E in the base resin as needed, as well as a structural unit represented by the following formula (f0) (hereinafter, Also referred to as "structural unit F").
• R 13 is a hydrogen atom, a methyl group, or a trifluoromethyl group.
• G L 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.
• 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 or -COO-, and -COO- is more preferable.
• R 14 As 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. Mention may be made of 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, such as a 2,2,2-trifluoroethyl group or a 1,1,1,3,3,3-hexafluoropropyl group. More preferred are 5,5,5-trifluoro-1,1-diethylpentyl group and 1,1,1,2,2,3,3-heptafluoro-6-methylheptan-4-yl group.
• a fluorinated chain hydrocarbon group more preferably a fluorinated alkyl group, such as a 2,2,2-trifluoroethyl group or a 1,1,1,3,3,3-hexafluoropropyl group. More preferred are 5,5,5-trifluoro-1,1-diethylpentyl group and 1,1,1,2,2,3,3-heptafluoro-6-methylheptan-4-yl group.
• the content ratio of the structural unit F is preferably 20 mol% or more, more preferably 30 mol% or more, based on the total structural units constituting the high fluorine content resin. Preferably, 40 mol% or more is more preferable. Further, the content ratio is preferably 100 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less.
• the high fluorine content resin may have other structural units in addition to the structural unit F.
• Other structural units include a structural unit G having an alcoholic hydroxyl group and a fluorinated hydrocarbon group bonded to the carbon atom to which the alcoholic hydroxyl group is bonded; at least one member selected from the group consisting of an iodine atom and a bromine atom;
• a structural unit H containing the following is mentioned.
• the content ratio of the structural unit G is preferably 10 mol% or more, more preferably 15 mol% or more, based on the total structural units constituting the high fluorine content resin. Preferably, 20 mol% or more is 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.
• the content ratio of the structural unit H is preferably 1 mol% or more, more preferably 3 mol% or more, based on the total structural units constituting the high fluorine content resin. It is preferably 5 mol% or more, and more preferably 5 mol% or more.
• the content ratio is preferably 400 mol% or less, more preferably 30 mol% or less, and even more preferably 20 mol% or less.
• the Mw of the high fluorine content resin is preferably 1,000 or more, more preferably 2,000 or more, even more preferably 3,000 or more, and particularly preferably 5,000 or more.
• the above Mw is preferably 50,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, and particularly preferably 15,000 or less.
• the Mw/Mn of the high fluorine content resin is usually 1 or more, more preferably 1.1 or more.
• the Mw/Mn is usually 5 or less, preferably 3 or less, more preferably 2.5 or less, and even more preferably 2.2 or less.
• the content of the high fluorine content resin is preferably 1 part by mass or more, more preferably 2 parts by mass or more, based on 100 parts by mass of the above base resin (total amount when including radiation-sensitive acid generating resin and resin). It is preferably 3 parts by mass or more, and more preferably 3 parts by mass or more. The content is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less.
• the radiation-sensitive resin composition may contain one or more types of high fluorine content resin.
• 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 to light. Since the onium salt contains at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group, high sensitivity and acid diffusion controllability are achieved by improving acid generation efficiency. It is possible to achieve excellent LWR performance.
• the onium salt contained in the radiation-sensitive resin composition may be a resin containing a structural unit B having the organic acid anion moiety and the onium cation moiety; a radiation-sensitive acid generator containing an onium cation moiety, and an acid containing the organic acid anion moiety and the onium cation moiety, which has a higher pKa than the acid generated from the radiation-sensitive acid generator upon irradiation with radiation.
• the acid diffusion control agent is preferably at least one selected from the group consisting of acid diffusion control agents that generate . The different functions will be explained below.
• the acid generated by exposure to the onium salt is thought to have two functions in the radiation-sensitive resin composition depending on the strength of the acid.
• the first function is that when the resin contains a structural unit having an acid-dissociable group, the acid generated by exposure dissociates the acid-dissociable group of the structural unit to generate a carboxy group, etc. It will be done.
• the onium salt having this first function is called a radiation-sensitive acid generator.
• the second function is that under the pattern forming conditions using the radiation-sensitive resin composition, the acid-dissociable groups of the resin are not substantially dissociated, and the acid-dissociable groups generated from the radiation-sensitive acid generator are generated in the unexposed areas.
• An example of this function is to suppress the diffusion of oxidized acids through salt exchange.
• the onium salt having this second function is called an acid diffusion control agent.
• the acid generated from the acid diffusion control agent can be said to be a relatively weaker acid (acid with a higher pKa) than the acid generated from the radiation-sensitive acid generator.
• an onium salt functions as a radiation-sensitive acid generator or an acid diffusion control agent is determined by the energy required to dissociate the acid-dissociable group of the resin and the acidity of the onium salt.
• the radiation-sensitive acid generator may be contained in the radiation-sensitive resin composition, even if the onium salt structure exists as a compound alone (free from the polymer), or the onium salt structure exists as a part of the polymer. It may be in an integrated form or in both of these forms.
• a form in which an onium salt structure is incorporated as a part of the polymer is particularly referred to as a radiation-sensitive acid generating resin.
• the radiation-sensitive resin composition contains the above-mentioned radiation-sensitive acid generator or radiation-sensitive acid-generating resin, the polarity of the resin in the exposed area increases, and the resin in the exposed area becomes difficult to develop in the case of alkaline aqueous solution development. On the other hand, in the case of organic solvent development, it becomes poorly soluble in the developer.
• the acid diffusion control agent in the radiation-sensitive resin composition, acid diffusion in unexposed areas can be suppressed, and a resist pattern with better pattern developability and LWR performance can be formed. can.
• the onium cation moiety in at least one selected from the group consisting of the radiation-sensitive acid generating resin, the radiation-sensitive acid generator, and the acid diffusion control agent is the fluorine atom. It is preferable that the aromatic ring structure has an aromatic ring structure.
• the organic acid anion moiety preferably has at least one selected from the group consisting of sulfonic acid anions, carboxylic acid anions, and sulfonimide anions.
• the onium cation moiety is preferably at least one selected from the group consisting of sulfonium cations and iodonium cations.
• acids generated upon exposure include those that generate sulfonic acids, carboxylic acids, and sulfonimides upon exposure, corresponding to the above-mentioned organic acid anions.
• an onium salt that gives sulfonic acid upon exposure to light (1) A compound in which one or more fluorine atoms or fluorinated hydrocarbon groups are bonded to the carbon atom adjacent to the sulfonic acid anion, (2) Examples include compounds in which neither a fluorine atom nor a fluorinated hydrocarbon group is bonded to the carbon atom adjacent to the sulfonic acid anion.
• Onium salts that give carboxylic acid upon exposure to light include: (3) a compound in which one or more fluorine atoms or fluorinated hydrocarbon groups are bonded to the carbon atom adjacent to the carboxylic acid anion; (4) Compounds in which neither a fluorine atom nor a fluorinated hydrocarbon group is bonded to a carbon atom adjacent to a carboxylic acid anion can be mentioned.
• the acid diffusion control agent is preferably one that falls under (2), (3) or (4) above, and particularly preferably one that falls under (2) or (4).
• the radiation-sensitive resin composition further includes a radiation-sensitive acid generator that generates an acid having a lower pKa than the acid generated from the acid diffusion control agent when irradiated with radiation (exposure).
• a radiation-sensitive acid generator that generates an acid having a lower pKa than the acid generated from the acid diffusion control agent when irradiated with radiation (exposure).
• the acid generated by exposure dissociates the acid-dissociable groups of the resin to generate carboxyl groups and the like.
• 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, while it becomes poorly soluble in the developer in the case of organic solvent development. Become.
• the radiation-sensitive acid generator includes an organic acid anion portion and an onium cation portion.
• the organic acid anion moiety preferably has at least one selected from the group consisting of sulfonic acid anions and sulfonimide anions. Examples of the acid generated by exposure include sulfonic acid and sulfonimide, corresponding to the organic acid anion moiety.
• the organic acid anion moiety includes an iodine-substituted aromatic ring structure.
• compounds in which one or more fluorine atoms or fluorinated hydrocarbon groups are bonded to the carbon atom adjacent to the sulfonic acid anion can be suitably employed as the radiation-sensitive acid generator that produces sulfonic acid upon exposure to light. .
• the radiation-sensitive acid generator is preferably represented by the following formula (A-1) or the following formula (A-2).
• L 1 is a single bond, an ether bond, an ester bond, or an alkylene group having 1 to 6 carbon atoms that may contain an ether bond or an ester bond. It is.
• 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, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, a pentafluorosulfanylthio group, or an amino group, or a fluorine atom, a chlorine atom, a bromine atom an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 10 carbon atoms, which may contain an 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, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, or an acyloxy group having 2 to 6 carbon atoms. 6 alkyl group.
• R 9 is an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and is a halogen atom, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, a carbon It may contain an acyl group having 2 to 6 carbon atoms or an acyloxy group having 2 to 6 carbon atoms.
• the alkyl group, alkoxy group, alkoxycarbonyl group, acyloxy group, acyl group, and alkenyl group may be linear, branched, or cyclic.
• R2 is a single bond or a divalent linking group having 1 to 20 carbon atoms; when p is 2 or 3, it is a trivalent or tetravalent linking group having 1 to 20 carbon atoms.
• 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, and at least one of them is a fluorine atom or a trifluoromethyl group. Furthermore, Rf 1 and Rf 2 may be combined to form a carbonyl group. In particular, it is preferable that both Rf 3 and Rf 4 are fluorine atoms.
• R 3 , R 4 , R 5 , R 6 and R 7 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms and which may contain a hetero atom. Further, any two of R 3 , R 4 and R 5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
• the above-mentioned 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.
• Examples include an alkynyl group, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms.
• some or all of the hydrogen atoms of these groups are a hydroxy group, a carboxy group, a halogen atom, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, a pentafluorosulfanylthio group, a cyano group, an amide group, a nitro group, It may be substituted with a mercapto group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and some of the carbon atoms of these groups are substituted with an ether bond, an ester bond, a carbonyl group, a carbonate group, or a sulfonic acid ester bond. may have been done.
• p is an integer satisfying 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 satisfying 1 ⁇ q ⁇ 3, and more preferably 2 or 3.
• r is preferably an integer satisfying 0 ⁇ r ⁇ 2.
• at least one R 1 is preferably a fluorine atom, a fluorinated hydrocarbon group, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group.
• at least one R 1 is more preferably a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group.
• the organic acid anion moiety of the radiation-sensitive acid generator represented by the above formulas (A-1) and (A-2) includes, but is not limited to, those shown below.
• the organic acid anion moiety that does not have an iodine-substituted aromatic ring structure a structure in which the iodine atom in the following formula is substituted with an atom or group other than the iodine atom, such as a hydrogen atom or other substituent, is preferably adopted. Can be done.
• the structure shown as the onium cation moiety in the structural unit B that can be included in the resin can be suitably adopted.
• onium cations containing an aromatic ring structure having a fluorine atom are preferred, and onium cations containing an aromatic ring structure having a fluorine atom, a CF3 group, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group are more preferred.
• onium cations containing an aromatic ring structure having a fluorine atom are preferred, and onium cations containing an aromatic ring structure having a fluorine atom, a CF3 group, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group are more preferred. preferable.
• the onium cation represented by the above formula (Q-1) can be mentioned, and in this case, at least one or more Ra 3 in the formula (Q-1) is a pentafluorosulfanyl group, a pentafluorosulfanyloxy or a pentafluorosulfanylthio group.
• 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, even more preferably 1.5 parts by mass, and 2 parts by mass based on 100 parts by mass of the base resin. Particularly preferred.
• the upper limit of the content is preferably 20 parts by mass or less, more preferably 18 parts by mass or less, even more preferably 15 parts by mass or less, and particularly preferably 12 parts by mass or less, based on 100 parts by mass of the resin. This makes it possible to exhibit excellent sensitivity and LWR performance during resist pattern formation.
• a radiation-sensitive acid generator containing at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and A radiation-sensitive acid generator containing no pentafluorosulfanylthio group (hereinafter also referred to as "other radiation-sensitive acid generator”) may be used in combination.
• the upper limit of the content of the other radiation-sensitive acid generators is preferably 45% by mass or less, and 35% by mass based on the total content of the radiation-sensitive acid generators. The following is more preferable, and 25% by mass or less is even more preferable.
• the lower limit of the content of other radiation-sensitive acid generators is 1% by mass or more based on the total content of radiation-sensitive acid generators.
• the acid diffusion control agent contains an organic acid anion portion and an onium cation portion, and upon irradiation with radiation, generates an acid having a higher pKa than the acid generated from the radiation-sensitive acid generator.
• organic acid anion moieties include carboxylic acids.
• the organic acid anion moiety includes an iodine-substituted aromatic ring structure.
• the acid diffusion control agent is preferably represented by the following formula (S-1) or the following formula (S-2).
• R 1 is a hydrogen atom, a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, a pentafluorosulfanylthio group, An alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, or an acyloxy group having 1 to 6 carbon atoms, which may be substituted with an amino group, a nitro group, a cyano group, or a halogen atom.
• 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.
• the above alkyl group having 1 to 6 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n- Examples include butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclobutyl group, n-pentyl group, cyclopentyl group, n-hexyl group, and cyclohexyl group.
• alkyl moiety of the alkoxy group having 1 to 6 carbon atoms, the acyloxy group having 2 to 7 carbon atoms, and the alkoxycarbonyl group having 2 to 7 carbon atoms the same examples as the above-mentioned alkyl groups can be mentioned
• Examples of the alkyl moiety of the alkylsulfonyloxy group having 1 to 4 carbon atoms include those having 1 to 4 carbon atoms among the aforementioned alkyl groups.
• the above alkenyl group having 2 to 8 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include a vinyl group, a 1-propenyl group, a 2-propenyl group, and the like.
• R 1 is a fluorine atom, a chlorine atom, a chlorine atom, a pentafluorosulfanyl group, a hydroxy group, an amino group, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and a 2-carbon atom.
• R 3 , R 4 , R 5 , R 6 and R 7 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms and which may contain a hetero atom.
• the onium cation moiety of the acid diffusion control agent has a fluorine atom
• at least one of R 3 , R 4 and R 5 contains one or more fluorine atoms
• at least one of R 6 and R 7 contains one or more fluorine atoms.
• any two of R 3 , R 4 and R 5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
• the above-mentioned 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. Examples include an alkynyl group, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms.
• some or all of the hydrogen atoms of these groups are substituted with a hydroxy group, a carboxy group, a halogen atom, a cyano group, an amide group, a nitro group, a mercapto group, a sultone group, a sulfone group, or a sulfonium salt-containing group.
• Some of the carbon atoms of these groups may be substituted with an ether bond, ester bond, carbonyl group, carbonate group, or sulfonic acid ester bond.
• L 1 is a single bond or a divalent linking group having 1 to 20 carbon atoms, such as 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 group. It may contain a group.
• n and n are integers satisfying 0 ⁇ m ⁇ 5, 0 ⁇ n ⁇ 3, and 0 ⁇ m+n ⁇ 5, but preferably integers satisfying 1 ⁇ m ⁇ 3 and 0 ⁇ n ⁇ 2.
• at least one R 1 is preferably a fluorine atom, a fluorinated hydrocarbon group, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group.
• at least one R 1 is more preferably a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group.
• the organic acid anion moiety of the acid diffusion control agent represented by the above formula (S-1) or (S-2) includes, but is not limited to, those shown below. All of the following are organic acid anion moieties that have an iodine-substituted aromatic ring structure, but as organic acid anion moieties that do not have an iodine-substituted aromatic ring structure, the iodine atom in the formula below can be replaced with a hydrogen atom or other A structure in which the iodine atom is substituted with an atom or group other than the iodine atom, such as a substituent group, can be suitably employed.
• the onium cation moiety in structural unit B of the radiation-sensitive acid generating resin can be suitably employed.
• onium cations containing an aromatic ring structure having a fluorine atom are preferred, and onium cations containing an aromatic ring structure having a fluorine atom, a CF3 group, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group are more preferred.
• onium cations containing an aromatic ring structure having a fluorine atom are preferred, and onium cations containing an aromatic ring structure having a fluorine atom, a CF3 group, a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, or a pentafluorosulfanylthio group are more preferred. preferable.
• an onium cation represented by the above formula (Q-1) can be mentioned, and in this case, at least one Ra 3 in the formula (Q-1) is a pentafluorosulfanyl group, a pentafluorosulfanyl group, etc. It is an oxy group or a pentafluorosulfanylthio group.
• the acid diffusion control agents 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.
• the content ratio of the acid diffusion control agent is the content of the radiation-sensitive acid generator (if a radiation-sensitive acid-generating resin is included, the total content of structural unit B in 100 parts by mass of the radiation-sensitive acid-generating resin) 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more. Further, the above ratio is preferably 100% by mass or less, more preferably 80% by mass or less, and even more preferably 60% by mass or less. This makes it possible to exhibit excellent sensitivity and LWR performance during resist pattern formation.
• 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 base resin (at least one of the radiation-sensitive acid generating resin and the resin) and optionally contained additives.
• 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 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; Polyhydric carboxylic acid diester solvents such as propylene glycol diacetate, methoxytriglycol acetate, diethyl oxalate, ethyl acetoacetate, ethyl lactate, and diethyl phthalate can be mentioned.
• 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; Examples include aromatic hydrocarbon solvents such as benzene, toluene, di-iso-propylbenzene, and n-amylnaphthalene.
• 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 above-mentioned radiation-sensitive resin composition can be prepared, for example, by mixing the base resin, onium salt, solvent, and other arbitrary components as necessary in a predetermined ratio. After mixing, the radiation-sensitive resin composition is preferably filtered using, for example, a filter with a pore size of about 0.05 ⁇ 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.
• the compound according to this embodiment includes an onium salt containing an organic acid anion moiety and an onium cation moiety, and the onium salt is selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group. contains at least one group.
• the organic acid anion moiety may include at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group.
• the organic acid anion preferably has at least one selected from the group consisting of sulfonic acid anions, carboxylic acid anions, and sulfonimide anions.
• the onium cation moiety may include at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group.
• both the organic acid anion moiety and the onium cation moiety may contain at least one group selected from the group consisting of a pentafluorosulfanyl group, a pentafluorosulfanyloxy group, and a pentafluorosulfanylthio group. Since the compound according to the present embodiment has a high level of sensitivity, when used as a radiation-sensitive acid generator or an acid diffusion control agent in a radiation-sensitive resin composition, it has a high level of LWR performance and a process window. can be granted.
• the pattern forming method in this embodiment is as follows: 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”), and The method includes a step (3) of developing the exposed resist film (hereinafter also referred to as “developing step”).
• 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, cast 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 140°C, preferably 80°C to 120°C.
• the PB time is usually 5 seconds to 600 seconds, preferably 10 seconds 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 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 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 medium 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
• aqueous alkaline solutions 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.
• organic solvent include one or more of the solvents listed as the solvent for the radiation-sensitive resin composition described above.
• ester solvents and ketone solvents are preferred.
• the ester solvent an acetate ester solvent is preferred, and n-butyl acetate and amyl acetate are more preferred.
• ketone solvent chain ketones are preferred, and 2-heptanone is 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.
• 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 mentioned.
• Mw and Mn of the polymer were 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 1.0mL/min
• Sample concentration 1.0% by mass
• Sample injection volume 100 ⁇ L
• Polymer synthesis example 1 Synthesis of polymer (A-1) Compound (M-1) and compound (M-3) were mixed with 1-methoxy-2-propanol (all monomers) so that the molar ratio was 40/60. 200 parts by mass). Next, azobisisobutyronitrile was added as an initiator in an amount of 6 mol % based on the total monomers to prepare a monomer solution. Meanwhile, 1-methoxy-2-propanol (100 parts by mass based on the total amount of monomers) was added to an empty reaction vessel, and the mixture was heated to 85° C. with stirring. Next, the monomer solution prepared above was added dropwise over 3 hours, and then heated at 85° C. for an additional 3 hours.
• the polymerization solution was cooled to room temperature.
• the cooled polymerization solution was poured into hexane (500 parts by mass based on the polymerization solution), and the precipitated white powder was filtered out.
• the filtered white powder was washed twice with 100 parts by mass of hexane based on the polymerization solution, 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 thereto, and a hydrolysis reaction was carried out at 70° C. for 6 hours with stirring.
• Polymer synthesis examples 2 to 9 Polymers (A-2) to (A-9) were also synthesized in the same manner as in Synthesis Example 1 above, except that the monomer types and ratios were changed.
• Radiation-sensitive acid generators represented by formulas (B-2) to (B-4) can be obtained by appropriately selecting a precursor and selecting the same formulation as in Synthesis Example 1 of radiation-sensitive acid generator. synthesized the agent.
• TPS+ is a triphenylsulfonium cation.
• the reaction product was extracted with acetonitrile, and the solvent was distilled off to obtain a sulfonate compound.
• 26.0 mmol of triphenylsulfonium chloride was added to the above sulfonate compound, and a mixed solution of water:dichloromethane (1:3 (mass ratio)) was added to obtain a 0.5M solution.
• dichloromethane was added for extraction and the organic layer was separated.
• the obtained organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off.
• a radiation-sensitive acid generator represented by the following formula (B-8) was obtained.
• the synthesis scheme of the radiation-sensitive acid generator (B-8) is shown below.
• the radiation-sensitive acid generator used in each example and comparative example is shown below.
• Acid diffusion control agent represented by formula (D-2) was synthesized by selecting a precursor and selecting the same formulation as in acid diffusion control agent synthesis example 2.
• Example 1 [A] 100 parts by mass of polymer (A-1), [B] 20 parts by mass of (B-1) as a radiation-sensitive acid generator, [D] (D-3) as an acid diffusion control agent ( B-1), 20 mol%, [D] 4,800 parts by mass of (E-1) as an organic solvent, and 2,000 parts by mass of (E-2) were mixed, and the resulting mixture was mixed.
• a radiation-sensitive resin composition (R-1) was prepared by filtering through a membrane filter with a pore size of 0.20 ⁇ m.
• PEB post-exposure bake
• the exposure amount for forming a 32 nm line-and-space pattern was defined as the optimum exposure amount, and this optimum exposure amount was defined as Eop (unit: mJ/cm 2 ).
• Eop unit: mJ/cm 2
• the sensitivity was evaluated as "A” if Eop was 30 mJ/ cm2 or less, "B” if it was more than 30 mJ/ cm2 and not more than 32 mJ/cm2, and "C” if it exceeded 32 mJ/ cm2 .
• LWR performance The formed resist pattern was observed from above using the scanning electron microscope. The line width was measured at a total of 50 points at arbitrary locations, a 3 sigma value was determined from the distribution of the measured values, and this was defined as LWR (unit: nm). The LWR performance indicates that the smaller the LWR value, the smaller the line wobbling, and the better. The LWR performance was evaluated as "A” if the LWR was 4.0 nm or less, "B” if it was more than 4.0 nm and not more than 4.2 nm, and "C” if it exceeded 4.2 nm.
• Process window means a range of resist dimensions that allows formation of a pattern without bridge defects or collapse.
• CD margin Crritical Dimension
• the CD margin was 30 nm or more, it was evaluated as "A,” when it was 28 nm or more and less than 30 nm, it was evaluated as "B,” and when it was less than 28 nm, it was evaluated as "C.”
• the radiation-sensitive resin composition, resist pattern forming method, etc. of the present invention sensitivity, LWR performance, and process window can be improved compared to conventional methods. Therefore, these can be suitably used for forming fine resist patterns in the lithography process of various electronic devices such as semiconductor devices and liquid crystal devices.

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