Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/0045—Photosensitive materials with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
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  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C309/00—Sulfonic acids; Halides, esters, or anhydrides thereof
  • C07C309/01—Sulfonic acids
  • C07C309/02—Sulfonic acids having sulfo groups bound to acyclic carbon atoms
  • C07C309/03—Sulfonic acids having sulfo groups bound to acyclic carbon atoms of an acyclic saturated carbon skeleton
  • C07C309/07—Sulfonic acids having sulfo groups bound to acyclic carbon atoms of an acyclic saturated carbon skeleton containing oxygen atoms bound to the carbon skeleton
  • C07C309/12—Sulfonic acids having sulfo groups bound to acyclic carbon atoms of an acyclic saturated carbon skeleton containing oxygen atoms bound to the carbon skeleton containing esterified hydroxy groups bound to the carbon skeleton
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  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C309/00—Sulfonic acids; Halides, esters, or anhydrides thereof
  • C07C309/01—Sulfonic acids
  • C07C309/02—Sulfonic acids having sulfo groups bound to acyclic carbon atoms
  • C07C309/03—Sulfonic acids having sulfo groups bound to acyclic carbon atoms of an acyclic saturated carbon skeleton
  • C07C309/17—Sulfonic acids having sulfo groups bound to acyclic carbon atoms of an acyclic saturated carbon skeleton containing carboxyl groups bound to the carbon skeleton
• • 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
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D313/00—Heterocyclic compounds containing rings of more than six members having one oxygen atom as the only ring hetero atom
  • C07D313/02—Seven-membered rings
  • C07D313/06—Seven-membered rings condensed with carbocyclic rings or ring systems
  • C07D313/08—Seven-membered rings condensed with carbocyclic rings or ring systems condensed with one six-membered ring
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  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D313/00—Heterocyclic compounds containing rings of more than six members having one oxygen atom as the only ring hetero atom
  • C07D313/02—Seven-membered rings
  • C07D313/06—Seven-membered rings condensed with carbocyclic rings or ring systems
  • C07D313/10—Seven-membered rings condensed with carbocyclic rings or ring systems condensed with two six-membered rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D313/00—Heterocyclic compounds containing rings of more than six members having one oxygen atom as the only ring hetero atom
  • C07D313/16—Eight-membered rings
  • C07D313/20—Eight-membered rings condensed with carbocyclic rings or ring systems
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D317/00—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms
  • C07D317/08—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3
  • C07D317/10—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings
  • C07D317/14—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings with substituted hydrocarbon radicals attached to ring carbon atoms
  • C07D317/16—Radicals substituted by halogen atoms or nitro radicals
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D317/00—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms
  • C07D317/08—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3
  • C07D317/10—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings
  • C07D317/14—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings with substituted hydrocarbon radicals attached to ring carbon atoms
  • C07D317/18—Radicals substituted by singly bound oxygen or sulfur atoms
  • C07D317/24—Radicals substituted by singly bound oxygen or sulfur atoms esterified
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D317/00—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms
  • C07D317/08—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3
  • C07D317/44—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 ortho- or peri-condensed with carbocyclic rings or ring systems
  • C07D317/70—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 ortho- or peri-condensed with carbocyclic rings or ring systems condensed with ring systems containing two or more relevant rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D327/00—Heterocyclic compounds containing rings having oxygen and sulfur atoms as the only ring hetero atoms
  • C07D327/02—Heterocyclic compounds containing rings having oxygen and sulfur atoms as the only ring hetero atoms one oxygen atom and one sulfur atom
  • C07D327/04—Five-membered rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D493/00—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system
  • C07D493/02—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system in which the condensed system contains two hetero rings
  • C07D493/08—Bridged systems
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D493/00—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system
  • C07D493/12—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system in which the condensed system contains three hetero rings
  • C07D493/18—Bridged systems
• • 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
  • G03F7/0046—Photosensitive materials with perfluoro compounds, e.g. for dry lithography
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
  • G03F7/0382—Macromolecular compounds which are rendered insoluble or differentially wettable the macromolecular compound being present in a chemically amplified negative 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
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
  • G03F7/0388—Macromolecular compounds which are rendered insoluble or differentially wettable with ethylenic or acetylenic bands in the side chains of the photopolymer
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
• • 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
  • G03F7/30—Imagewise removal using liquid means
  • G03F7/32—Liquid compositions therefor, e.g. developers
  • G03F7/322—Aqueous alkaline compositions
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2601/00—Systems containing only non-condensed rings
  • C07C2601/06—Systems containing only non-condensed rings with a five-membered ring
  • C07C2601/08—Systems containing only non-condensed rings with a five-membered ring the ring being saturated
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2601/00—Systems containing only non-condensed rings
  • C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
  • C07C2601/14—The ring being saturated
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2602/00—Systems containing two condensed rings
  • C07C2602/36—Systems containing two condensed rings the rings having more than two atoms in common
  • C07C2602/42—Systems containing two condensed rings the rings having more than two atoms in common the bicyclo ring system containing seven carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2603/00—Systems containing at least three condensed rings
  • C07C2603/56—Ring systems containing bridged rings
  • C07C2603/58—Ring systems containing bridged rings containing three rings
  • C07C2603/70—Ring systems containing bridged rings containing three rings containing only six-membered rings
  • C07C2603/74—Adamantanes
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/70—Microphotolithographic exposure; Apparatus therefor
  • G03F7/70008—Production of exposure light, i.e. light sources
  • G03F7/70033—Production of exposure light, i.e. light sources by plasma extreme ultraviolet [EUV] sources

Definitions

• the present invention relates to a radiation-sensitive composition, a pattern forming method, and a radiation-sensitive acid generator.
• Photolithography technology uses a resist composition to form fine circuits in semiconductor elements.
• a coating of the resist composition is exposed to radiation through a mask pattern to generate an acid, which is then catalyzed by a reaction that creates a difference in the solubility of the resin in alkaline or organic developing solutions between exposed and unexposed areas, forming a resist pattern on a substrate.
• the above photolithography technology is promoting finer patterns by using short-wavelength radiation such as ArF excimer lasers, and also by using liquid immersion lithography, in which exposure is performed while the space between the lens of the exposure device and the resist film is filled with a liquid medium.
• Lithography using even shorter-wavelength radiation such as electron beams, X-rays, and EUV (extreme ultraviolet) is also being considered as a next-generation technology.
• photoacid generators which are one of the main components of resist compositions, in order to form finer resist patterns (for example, JP 2020-75910 A and Japanese Patent No. 5083528).
• the resist composition is required to have various resist properties such as LWR (Line Width Roughness), which indicates the variation in sensitivity, line width, and line width of the resist pattern, pattern rectangularity, which indicates the rectangularity of the cross-sectional shape of the resist pattern, development defect performance, EL (Exposure Latitude), critical dimension uniformity (CDU), which is an index of the uniformity of the hole diameter, and pattern circularity, which indicates the circularity of the hole shape.
• LWR Line Width Roughness
• pattern rectangularity which indicates the rectangularity of the cross-sectional shape of the resist pattern
• development defect performance EL (Exposure Latitude)
• CDU critical dimension uniformity
• pattern circularity which indicates the circularity of the hole shape.
• the present invention aims to provide a radiation-sensitive composition, a pattern formation method, and a radiation-sensitive acid generator capable of forming a resist film that exhibits sufficient levels of sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity.
• the present invention provides An onium salt compound represented by the following formula (1) (hereinafter also referred to as “onium salt compound (1)”)):
• the present invention relates to a radiation-sensitive composition comprising a polymer including a structural unit having an acid-dissociable group, and a solvent.
• W is an organic group having 3 to 40 carbon atoms and at least one ring structure.
• L is a linking group having a valence of (r+1), and r is an integer from 1 to 3.
• r is 1, both p and q are integers from 1 to 3, and when r is 2 to 3, each of the multiple p's and q's is an integer from 0 to 3.
• M + is a monovalent onium cation.
• the radiation-sensitive composition contains onium salt compound (1), and thus can form a resist film that exhibits excellent sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity at sufficient levels. The reason for this is presumed to be as follows, without being bound by any theory.
• the anion of the onium salt compound (1) has a carboxyl group and a hydroxyl group, and these groups interact with the polymer in the composition, thereby appropriately shortening the diffusion length of the generated acid and improving LWR and EL.
• the anion of the onium salt compound (1) has a carboxyl group and a hydroxyl group, the solubility in the developer is greatly improved and the amount of insoluble components is reduced, so that development defects can be suppressed more efficiently and it is presumed that the desired resist performance can also be exhibited.
• the present invention provides a method for producing a pharmaceutical composition comprising the steps of: a step of directly or indirectly applying the radiation-sensitive composition to a substrate to form a resist film; exposing the resist film to light; and developing the exposed resist film with a developer.
• the pattern formation method uses the above-mentioned radiation-sensitive composition, which is capable of forming a resist film that is excellent in sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity, making it possible to efficiently form a high-quality resist pattern.
• the present invention provides a method for producing a pharmaceutical composition comprising the steps of:
• the present invention relates to a radiation-sensitive acid generator represented by the following formula (1).
• W is an organic group having 3 to 40 carbon atoms and at least one ring structure.
• L is a linking group having a valence of (r+1), and r is an integer from 1 to 3.
• r is 1, both p and q are integers from 1 to 3, and when r is 2 to 3, each of the multiple p's and q's is an integer from 0 to 3.
• M + is a monovalent onium cation.
• the radiation-sensitive acid generator is composed of an onium salt compound (1) having the above-mentioned specific structure, and when used in a radiation-sensitive composition, it can impart good sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity to the resist film obtained.
• the radiation-sensitive composition according to this embodiment contains an onium salt compound (1), a polymer containing a structural unit having an acid-dissociable group, and a solvent.
• the composition may contain other optional components as long as the effects of the present invention are not impaired.
• the radiation-sensitive composition contains a specific onium salt compound (1) as a radiation-sensitive acid generator,
• the radiation-sensitive composition can impart to a resist film a high level of sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU and pattern circularity.
• the onium salt compound (1) is represented by the above formula (1) and functions as a radiation-sensitive acid generator that generates an acid by irradiation with radiation. Depending on the structure of the onium salt compound (1), it can also function as a radiation-sensitive strong acid generator, and can also function as an acid diffusion control agent that generates an acid having a higher pKa than the acid generated from the radiation-sensitive strong acid generator by irradiation with radiation. In the present invention, it is preferable to use the onium salt compound (1) as a radiation-sensitive strong acid generator from the viewpoint of development defect performance.
• the onium salt compound (1) as a radiation-sensitive strong acid generator will be described.
• the organic group having 3 to 40 carbon atoms and at least one ring structure represented by W is not particularly limited, and may be either a group containing only a ring structure or a group combining a ring structure and a chain structure.
• the ring structure may be a monocyclic ring, a polycyclic ring, or a combination of these.
• the ring structure may be an alicyclic structure, an aromatic ring structure, a heterocyclic structure, or a combination of these.
• the ring structure may be a structure in which the ring structure is bonded to a chain structure, or two or more ring structures may form a condensed ring structure or a bridged ring structure.
• the number of ring structures in the organic group may be one or more, or may be two or more.
• the above-mentioned divalent heteroatom-containing group may be present between the carbon-carbons forming the skeleton of the ring structure or the chain structure, and the hydrogen atoms on the carbon atoms of the ring structure or the chain structure may be substituted with other substituents.
• the above alicyclic structure may be a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms.
• the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms may be a monocyclic or polycyclic saturated hydrocarbon group, or a monocyclic or polycyclic unsaturated hydrocarbon group.
• Preferred monocyclic saturated hydrocarbon groups are cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.
• Preferred polycyclic cycloalkyl groups are bridged alicyclic hydrocarbon groups such as norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl.
• Preferred monocyclic unsaturated hydrocarbon groups are monocyclic cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl.
• Preferred polycyclic unsaturated hydrocarbon groups are polycyclic cycloalkenyl groups such as norbornenyl, tricyclodecenyl, and tetracyclododecenyl.
• a bridged alicyclic hydrocarbon group refers to a polycyclic alicyclic hydrocarbon group in which two carbon atoms that are not adjacent to each other among the carbon atoms that make up the alicyclic ring are bonded together by a bond chain that contains one or more carbon atoms.
• the aromatic ring structure may be a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.
• the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group; and aralkyl groups such as a benzyl group, a phenethyl group, and a naphthylmethyl group.
• heterocyclic structures include groups in which one hydrogen atom has been removed from an aromatic heterocyclic structure and groups in which one hydrogen atom has been removed from an alicyclic heterocyclic structure.
• Five-membered aromatic structures that have aromaticity due to the introduction of a heteroatom are also included in the heterocyclic structure.
• heteroatoms include an oxygen atom, a nitrogen atom, and a sulfur atom.
• aromatic heterocyclic structure examples include: Oxygen atom-containing aromatic heterocyclic structures such as furan, pyran, benzofuran, and benzopyran; nitrogen atom-containing aromatic heterocyclic structures such as pyrrole, imidazole, pyridine, pyrimidine, pyrazine, indole, quinoline, isoquinoline, acridine, phenazine, and carbazole; Sulfur-containing aromatic heterocyclic structures such as thiophene;
• heterocyclic ring include aromatic heterocyclic structures containing a plurality of heteroatoms, such as thiazole, benzothiazole, thiazine, and oxazine.
• Examples of the alicyclic heterocyclic structure include Oxygen atom-containing alicyclic heterocyclic structures such as oxirane, tetrahydrofuran, tetrahydropyran, dioxolane, and dioxane; Nitrogen atom-containing alicyclic heterocyclic structures such as aziridine, pyrrolidine, piperidine, and piperazine; Sulfur atom-containing alicyclic heterocyclic structures such as thietane, thiolane, and thiane; Alicyclic heterocyclic structures containing multiple heteroatoms, such as morpholine, 1,2-oxathiolane, and 1,3-oxathiolane; Examples of such structures include lactone structures, cyclic carbonate structures, and sultone structures.
• Oxygen atom-containing alicyclic heterocyclic structures such as oxirane, tetrahydrofuran, tetrahydropyran, dioxolane, and dioxane
• the heterocyclic structure includes a lactone structure, a cyclic carbonate structure, a sultone structure, a cyclic acetal, or a combination thereof.
• the chain structure may be a monovalent chain organic group having 1 to 30 carbon atoms.
• the monovalent chain organic group having 1 to 30 carbon atoms there is no particular limitation on the monovalent chain organic group having 1 to 30 carbon atoms, so long as it has a chain structure.
• Examples of the chain structure include a monovalent chain hydrocarbon group having 1 to 30 carbon atoms, whether saturated or unsaturated, linear or branched, a group in which some or all of the hydrogen atoms contained in the chain hydrocarbon group have been replaced with a substituent, a group containing a divalent heteroatom-containing group between the carbon-carbon bonds of these groups, or a combination of these.
• the monovalent chain hydrocarbon group having 1 to 30 carbon atoms may, for example, be a linear or branched saturated hydrocarbon group having 1 to 30 carbon atoms, or a linear or branched unsaturated hydrocarbon group having 1 to 30 carbon atoms.
• the linear or branched saturated hydrocarbon group having 1 to 30 carbon atoms may, for example, be an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an i-hexyl group, an n-heptyl group, or an i-heptyl group.
• an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, a 1-methylpropyl group, a t-butyl group, an n-pent
• the linear or branched unsaturated hydrocarbon group having 1 to 30 carbon atoms may, for example, be an alkenyl group such as an ethenyl group, a propenyl group, or a butenyl group; or an alkynyl group such as an ethynyl group, a propynyl group, or a butynyl group.
• R'' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 5 carbon atoms.
• the number of the divalent heteroatom-containing groups is preferably 1, 2 or 3, and more preferably 1 or 2.
• the carboxyl group and hydroxyl group bonded to W in the above formula (1) are not particularly limited in their bonding positions and may be bonded anywhere on the structure represented by W. It is preferable that they are bonded directly or indirectly to the same or different ring structures, more preferably that they are bonded directly to the same or different ring structures, and even more preferably that they are bonded directly to the same ring structure and at least one hydroxyl group is bonded to a carbon atom adjacent to the carbon atom to which the carboxyl group is bonded.
• the partial structure "-W(OH) p (COOH) q " in the above formula (1) preferably contains one or more groups selected from the group consisting of groups represented by the following formulae (W-1) to (W-5).
• W-1 to (W-5) preferably contains one or more groups selected from the group consisting of groups represented by the following formulae (W-1) to (W-5).
• s is an integer of 0 to 2
• t is an integer of 1 to 3
• l, m, and n are each independently 1 to 6
• X is a hydrogen atom, an organic group having 1 to 12 carbon atoms, a cyano group, a hydroxyl group, or a halogen atom
• b is 1 to 10.
• R 1 and R 2 are the same or different and are a single bond or a divalent organic group.
• s is an integer of 0 to 2, preferably 0 or 1.
• t is an integer of 1 to 3, preferably 1 or 2.
• l, m, and n are each independently an integer of 1 to 6, preferably l is 2, m is 1, and n is 2.
• Examples of the organic group having 1 to 12 carbon atoms for X in the above formulas (W-1) to (W-5) include a hydrocarbon group having 1 to 12 carbon atoms and a monovalent organic group having 1 to 12 carbon atoms and represented by -X 1 -Y-X 2 (wherein X 1 is a single bond or a divalent hydrocarbon group having 1 to 11 carbon atoms; Y is -O-, -CO-, -COO-, -OCO-, -OCOO-, -NHCO- or -CONH-; and X 2 is a monovalent hydrocarbon group having 1 to 12 carbon atoms).
• hydrocarbon group having 1 to 12 carbon atoms for X and X2 examples include a monovalent chain hydrocarbon group having 1 to 12 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, or a combination thereof.
• the monovalent chain hydrocarbon group having 1 to 12 carbon atoms a group corresponding to a carbon number of 1 to 12 among the monovalent chain hydrocarbon groups having 1 to 30 carbon atoms in W of the above formula (1) can be suitably used.
• the monovalent alicyclic hydrocarbon group having 3 to 12 carbon atoms a group corresponding to a carbon number of 3 to 12 among the monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms in W of the above formula (1) can be suitably used.
• the monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms a group corresponding to 6 to 12 carbon atoms among the monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms in W of the above formula (1) can be suitably used.
• divalent hydrocarbon group having 1 to 11 carbon atoms represented by X1 a group in which one hydrogen atom has been removed from a group corresponding to the carbon number of 1 to 11, among the groups exemplified as the hydrocarbon group having 1 to 12 carbon atoms, can be suitably used.
• halogen atom represented by X examples include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom and an iodine atom being preferred.
• b is an integer from 1 to 3, and is preferably 1 or 2. When b is 2 or more, the multiple Xs may be the same or different.
• Examples of the divalent organic group represented by R 1 and R 2 include divalent organic groups having 1 to 30 carbon atoms, such as divalent hydrocarbon groups having 1 to 30 carbon atoms, groups containing a divalent heteroatom-containing group between the carbon atoms of this hydrocarbon group or at either terminal, and groups in which some or all of the hydrogen atoms in such groups and the above-mentioned hydrocarbon groups have been substituted with monovalent heteroatom-containing groups.
• Examples of the divalent organic group having 1 to 30 carbon atoms include a monovalent linear hydrocarbon group having 1 to 30 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms in W in formula (1) from which one hydrogen atom has been removed. Further examples include a group from which two hydrogen atoms have been removed from the aromatic heterocyclic structure in W in formula (1) and a group from which two hydrogen atoms have been removed from the alicyclic heterocyclic structure.
• the divalent heteroatom-containing group in W in formula (1) above can be suitably used.
• Examples of the monovalent heteroatom-containing group include halogen atoms such as fluorine, chlorine, bromine, and iodine atoms, hydroxyl groups, carboxyl groups, cyano groups, amino groups, and sulfanyl groups (-SH).
• halogen atoms such as fluorine, chlorine, bromine, and iodine atoms
• hydroxyl groups carboxyl groups
• cyano groups amino groups
• sulfanyl groups sulfanyl groups
• R 1 and R 2 are preferably a single bond, a divalent chain hydrocarbon group, or a group containing a divalent heteroatom-containing group between the carbon atoms of a divalent chain hydrocarbon group, and more preferably a single bond.
• the partial structure "-W(OH) p (COOH) q " in the above formula (1) is Contains one or more groups selected from the group consisting of groups represented by the following formulas (W-6) to (W-9), It is preferable that the compound contains one or more groups selected from the group consisting of groups represented by the following formulas (W-10) to (W-13).
• one or more groups selected from the group consisting of groups represented by the above formulas (W-6) to (W-9) and one or more groups selected from the group consisting of groups represented by the above formulas (W-10) to (W-13) may be bonded via a divalent organic group.
• Such a divalent organic group may, for example, be a divalent organic group represented by -X 1 -Y-X 1 -.
• the X 1 and Y are the same as those in the formulae (W-1) to (W-5) above.
• the two X 1 's may be the same or different.
• L is a (r+1)-valent linking group, and r is 1 to 3, preferably 1 or 2.
• r is 1 to 3, preferably 1 or 2.
• p and q are both 1 to 3
• the multiple p's and q's are each 0 to 3.
• at least one of the multiple p's is 1 or greater
• at least one of the multiple q's is 1 or greater.
• the (r+1)-valent linking group represented by L above can be a group having one or more linking groups selected from the group consisting of ether bonds, amide bonds, ester bonds, and acetal bonds.
• the L is at least one structure selected from the structures represented by the following formulas (L-1) to (L-5).
• R 11 is a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 12 carbon atoms.
• R 12 is a substituted or unsubstituted divalent hydrocarbon group having 1 to 12 carbon atoms. * is a bond bonding to W in formula (1) above, and ** is a bond bonding to S in SO 3 — in formula (1) above.
• R 13 is a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 12 carbon atoms.
• R 14 is a substituted or unsubstituted divalent hydrocarbon group having 1 to 12 carbon atoms.
• * is a bond bonding to W in formula (1) above, and ** is a bond bonding to S in SO 3 — in formula (1) above.
• R 21 and R 22 are the same or different and are substituted or unsubstituted divalent hydrocarbon groups having 1 to 12 carbon atoms, and a is an integer of 1 to 3.
• * is a bond bonding to W in formula (1), and ** is a bond bonding to S in SO 3 — in formula (1).
• Y 11 and Y 12 are each independently an oxygen atom or a sulfur atom.
• R 41 is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, or a monovalent organic group having 1 to 12 carbon atoms and represented by -X 1 -Y-X 2 (wherein X 1 is a single bond or a divalent hydrocarbon group having 1 to 11 carbon atoms; Y is -O-, -CO-, -COO-, -OCO-, -OCOO-, -NHCO- or -CONH-; and X 2 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms).
• R 42 is a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms.
• R 43 is a single bond or a divalent organic group.
• Q is selected from Y 11 and Y 12 and the carbon atom to which they are bonded form a single ring or a condensed ring. * is a bond bonded to W in the above formula (1), and ** is a bond bonded to S in SO 3 - in the above formula (1).
• R 44 is a single bond or a divalent organic group. * is a bond bonded to W in formula (1), and ** is a bond bonded to S in SO 3 — in formula (1).
• the divalent hydrocarbon groups having 1 to 12 carbon atoms represented by R 11 , R 12 , R 13 , R 14 , R 21 and R 22 in the above formulas (L-1) to (L-3) can suitably be groups in which one hydrogen atom has been removed from the groups exemplified as the hydrocarbon groups having 1 to 12 carbon atoms for X in the above formulas (W-1) to (W-5).
• a group corresponding to a carbon atom number of 1 to 10 can be suitably adopted from among the groups exemplified as the hydrocarbon groups having 1 to 12 carbon atoms for X in the above formulas (W-1) to (W-5).
• the monovalent organic group having 1 to 12 carbon atoms and represented by -X 1 -Y-X 2 in the above formulas (L-4) and (L-5) has the same meaning as that in formulas (W-1) to (W-5).
• the divalent hydrocarbon group having 1 to 10 carbon atoms represented by R 42 in the above formulas (L-4) and (L-5) can be suitably a group obtained by removing one hydrogen atom from a group corresponding to a carbon atom having 1 to 10 carbon atoms, among the groups exemplified as the hydrocarbon groups having 1 to 12 carbon atoms for X in the above formulas (W-1) to (W-5).
• the divalent organic groups represented by R 43 and R 44 in the above formulae (L-4) and (L-5) the divalent organic groups represented by R 1 in the above formulae (W-1) to (W-5) can be suitably adopted.
• Examples of the substituents that replace some or all of the hydrogen atoms in the hydrocarbon group include the substituents in W in formula (1) above.
• the L may contain a ring structure, and the ring structure of the L and the ring structure of the W may form a spiro ring structure.
• the following spiro ring structure is formed.
• this is only one example of forming a spiro ring structure, and the present invention is not limited thereto.
• R 1 , R 2 , X, and b are the same as those defined in the formulae (W-1) to (W-4), and R 42 is the same as that defined in the formula (L-4).
• the onium salt compound (1) it is preferable that fluorine or a fluorinated hydrocarbon group is bonded to the carbon atom adjacent to the sulfur atom of the sulfonate ion (SO 3 ⁇ ) so that the compound functions sufficiently as a radiation-sensitive strong acid generator.
• anion of the onium salt compound (1) as a radiation-sensitive strong acid generator include, but are not limited to, structures of the following formulas (1-1-1) to (1-1-36).
• examples of the monovalent onium cation represented by M + include radioactive onium cations containing elements such as S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, Te, and Bi.
• examples of the radioactive onium cation include sulfonium cation, tetrahydrothiophenium cation, iodonium cation, phosphonium cation, diazonium cation, and pyridinium cation. Among these, sulfonium cation or iodonium cation is preferred.
• the sulfonium cation or iodonium cation is preferably represented by the following formulae (X-1) to (X-6).
• R a1 , R a2 and R a3 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group or an alkoxycarbonyloxy group, a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a hydroxy group, a halogen atom, -OSO 2 -R P , -SO 2 -R Q , -S-R T , -O-, -CO- or a combination thereof, or a ring structure formed by combining two or more of these groups with each other.
• the ring structure may contain a heteroatom such as O or S between the carbon-carbon bonds that form the skeleton.
• R P , R Q and R T are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms.
• k1, k2 and k3 are each independently an integer of 0 to 5.
• R b1 is a substituted or unsubstituted linear or branched alkyl group or alkoxy group having 1 to 20 carbon atoms, an alkoxyalkyloxy group, a substituted or unsubstituted acyl group having 2 to 8 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, or a hydroxy group.
• n k is 0 or 1. When n k is 0, k4 is an integer of 0 to 4, and when n k is 1, k4 is an integer of 0 to 7.
• R b1 When there are multiple R b1 , the multiple R b1 may be the same or different, and the multiple R b1 may be combined with each other to form a ring structure.
• R b2 is a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms.
• L C is a single bond or a divalent linking group.
• k5 is an integer of 0 to 4.
• the multiple R b2 may be the same or different, and the multiple R b2 may combine with each other to form a ring structure.
• q is an integer of 0 to 3.
• the ring structure containing S + may contain a heteroatom such as O or S between the carbon-carbon bonds that form the skeleton.
• R c1 , R c2 and R c3 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms.
• R g1 is a substituted or unsubstituted linear or branched alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted acyl group having 2 to 8 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, or a hydroxy group.
• n k2 is 0 or 1. When n k2 is 0, k10 is an integer of 0 to 4, and when n k2 is 1, k10 is an integer of 0 to 7.
• R g1 When there are multiple R g1 , the multiple R g1 may be the same or different, and the multiple R g1 may be combined with each other to form a ring structure.
• R g2 and R g3 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group or an alkoxycarbonyloxy group, a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a hydroxy group, a halogen atom, or a ring structure formed by combining these groups together.
• k11 and k12 each independently represent an integer of 0 to 4.
• R g2 and R g3 each independently represent a plurality of R g2 and R g3
• the plurality of R g2 and R g3 may be the same or different.
• R d1 and R d2 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group or an alkoxycarbonyl group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a halogen atom, a halogenated alkyl group having 1 to 4 carbon atoms, a nitro group, or a ring structure formed by combining two or more of these groups.
• k6 and k7 each independently represent an integer of 0 to 5.
• R d1 and R d2 each represent a plurality of R d1 and R d2
• the plurality of R d1 and R d2 may each be the same or different.
• R e1 and R e2 each independently represent a halogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms.
• k8 and k9 each independently represent an integer of 0 to 4.
• radiation-sensitive onium cation examples include, but are not limited to, structures of the following formulas (1-2-1) to (1-2-54).
• the onium salt compound (1) as a radiation-sensitive strong acid generator can be obtained by appropriately combining the above anion with the above radiation-sensitive onium cation.
• Specific examples include, but are not limited to, structures of the following formulae (1-3-1) to (1-3-36).
• the lower limit of the content of the onium salt compound (1) as a radiation-sensitive strong acid generator is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, even more preferably 1 part by mass, and particularly preferably 3 parts by mass, per 100 parts by mass of the polymer described below.
• the upper limit of the content is preferably 50 parts by mass, more preferably 40 parts by mass, and even more preferably 35 parts by mass.
• the content of the onium salt compound (1) is appropriately selected depending on the type of polymer used, the exposure conditions, the desired sensitivity, and the like. This allows the resist pattern to exhibit excellent sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity when formed.
• the onium salt compound (1) as the radiation-sensitive strong acid generator can also be used in combination with other radiation-sensitive strong acid generators (for example, the onium salt compound (P1) below).
• the lower limit of the content of the onium salt compound (1) is preferably 35 mass%, more preferably 40 mass%, and even more preferably 45 mass%, based on the total mass of the radiation-sensitive strong acid generators contained in the composition.
• the upper limit is preferably 75 mass%, more preferably 70 mass%, and even more preferably 60 mass%. This makes it possible to exhibit excellent sensitivity, LWR, pattern rectangularity, EL, development defect performance, CDU, and pattern circularity when forming a resist pattern.
• W, q, p, r, L and M + are defined as in formula (1) above.
• the bromo portion of (a-1) can be converted to a sulfonate using a dithionite and an oxidizing agent, and then reacted with an onium cation halide salt (bromide salt in the scheme) corresponding to the onium cation to proceed with salt exchange, thereby synthesizing the desired onium salt compound (1) represented by formula (a-2).
• the desired onium salt compound (1) can be synthesized according to the synthesis scheme described in the Examples.
• the onium salt compound (1) also functions as an acid diffusion controller due to the structure of the onium salt compound (1).
• An example of the anion of the onium salt compound (1) serving as an acid diffusion controller is an anion in which neither a fluorine atom nor a fluorinated hydrocarbon group is bonded to the carbon atom bonded to the sulfur atom of SO 3 — in the anion of the onium salt compound (1) serving as a radiation-sensitive strong acid generator.
• the radiation-sensitive onium cation of the onium salt compound (1) serving as the acid diffusion control agent can preferably be the same as the radiation-sensitive onium cation of the onium salt compound (1) serving as the radiation-sensitive strong acid generator.
• the onium salt compound (1) as an acid diffusion control agent can be obtained by appropriately combining the above anion with the above radiation-sensitive onium cation.
• Specific examples include, but are not limited to, structures of the following formulae (1-4-1) to (1-4-34).
• the lower limit of the content of the onium salt compound (1) as an acid diffusion control agent is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, even more preferably 1 part by mass, and particularly preferably 3 parts by mass, per 100 parts by mass of the polymer described below.
• the upper limit of the content is preferably 40 parts by mass, more preferably 30 parts by mass, even more preferably 20 parts by mass, and particularly preferably 10 parts by mass.
• the content of the onium salt compound (1) is appropriately selected depending on the type of polymer used, the exposure conditions, the desired sensitivity, and the like. This makes it possible to exhibit excellent sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity when forming a resist pattern.
• the lower limit of the content of the onium salt compound (1) is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, even more preferably 1 part by mass, and particularly preferably 3 parts by mass.
• the upper limit of the content is preferably 40 parts by mass, more preferably 30 parts by mass, and even more preferably 20 parts by mass. This allows the resist pattern to exhibit excellent sensitivity, LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity when formed.
• the radiation-sensitive composition may contain a radiation-sensitive strong acid generator other than the onium salt compound (1) as the radiation-sensitive strong acid generator.
• Examples of the radiation-sensitive strong acid generator include onium salt compounds (P1) represented by the following formula (P1) (excluding those corresponding to the onium salt compound (1)).
• R 40 is a monovalent organic group having 3 to 40 carbon atoms containing a ring structure.
• R f21 and R f22 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group. When a plurality of R f21 and R f22 are present, the plurality of R f21 and R f22 are the same or different.
• n is an integer from 1 to 4.
• Z 2 + is a monovalent radiation-sensitive onium cation.
• a monovalent organic group having 3 to 40 carbon atoms and containing a ring structure represented by R40 a monovalent organic group having 3 to 40 carbon atoms and at least one ring structure, represented by W in the above formula (1), can be suitably used.
• Examples of the monovalent fluorinated hydrocarbon group represented by R f21 and R f22 include a monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms.
• Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms include: Fluorinated alkyl groups such as a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a 1,1,1,3,3,3-hexafluoropropyl group, a heptafluoro-n-propyl group, a heptafluoro-i-propyl group, a nonafluoro-n-butyl group, a nonafluoro-i-butyl group, a nonafluoro-t-butyl group, a 2,2,3,3,4,4,5,5-octafluoro-n-pentyl group, a tridecafluoro-n-hexyl group, and a 5,5,5-trifluoro-1,1-diethylpent
• Examples of the monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms include: fluorinated cycloalkyl groups such as a fluorocyclopentyl group, a difluorocyclopentyl group, a nonafluorocyclopentyl group, a fluorocyclohexyl group, a difluorocyclohexyl group, an undecafluorocyclohexylmethyl group, a fluoronorbornyl group, a fluoroadamantyl group, a fluorobornyl group, a fluoroisobornyl group, or a fluorotricyclodecyl group;
• Examples of the fluorinated cycloalkenyl group include a fluorocyclopentenyl group and a nonafluorocyclohexenyl group.
• the above-mentioned fluorinated hydrocarbon group is preferably a monovalent fluorinated chain hydrocarbon group having 1 to 8 carbon atoms, and more preferably a monovalent fluorinated straight chain hydrocarbon group having 1 to 5 carbon atoms.
• anion of the onium salt compound (P1) include, but are not limited to, structures of the following formulas (2-1-1) to (2-1-32).
• Specific examples of the radiation-sensitive onium cation of the onium salt compound (P1) are not limited, but the structures given as specific examples of the radiation-sensitive onium cation of formula (1) above can be suitably used.
• the onium salt compound (P1) may have a structure in which the above anion and the above radiation-sensitive onium cation are combined in any way.
• Specific examples of the onium salt compound (P1) include, but are not limited to, the onium salt compounds represented by the following formulas (2-1) to (2-32).
• the lower limit of the content of the onium salt compound (P1) (the total of the onium salt compounds (P1) when multiple types of onium salt compounds (P1) are included) is preferably 0 parts by mass, more preferably 0.1 parts by mass, even more preferably 0.5 parts by mass, and particularly preferably 3 parts by mass, per 100 parts by mass of the polymer described below.
• the upper limit of the content is preferably 50 parts by mass, more preferably 40 parts by mass, even more preferably 30 parts by mass, and particularly preferably 25 parts by mass.
• the content of the onium salt compound (P1) is appropriately selected depending on the type of polymer used, the exposure conditions, the desired sensitivity, etc.
• the polymer is an assembly of polymer chains including a structural unit having an acid-dissociable group (hereinafter, also referred to as “structural unit (I)”) (hereinafter, this assembly is also referred to as “base polymer”).
• the "acid-dissociable group” refers to a group that substitutes a hydrogen atom of a carboxy group, a phenolic hydroxyl group, an alcoholic hydroxyl group, a sulfo group, or the like, and dissociates under the action of an acid.
• the radiation-sensitive composition has excellent pattern formability because the polymer has the structural unit (I).
• the base polymer preferably contains a structural unit (II) containing at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure, which will be described later, and may contain structural units other than the structural units (I) and (II). Each structural unit will be described below.
• the structural unit (I) is a structural unit containing an acid-dissociable group.
• the structural unit (I) is not particularly limited as long as it contains an acid-dissociable group, and examples thereof include a structural unit having a tertiary alkyl ester moiety, a structural unit having a structure in which a hydrogen atom of a phenolic hydroxyl group is substituted with a tertiary alkyl group, and a structural unit having an acetal bond.
• a structural unit represented by the following formula (2) hereinafter also referred to as "structural unit (I-1)
• structural unit (I-1) is preferred.
• R 51 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R 52 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
• R 53 and R 54 each independently represent a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a divalent alicyclic group having 3 to 20 carbon atoms constituted by combining R 53 and R 54 together with the carbon atom to which they are bonded.
• L 81 is a single bond or a divalent organic group.
• R 51 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.
• Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 52 include a chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.
• chain hydrocarbon group having 1 to 10 carbon atoms represented by R 52 to R 54 above a group corresponding to a carbon number of 1 to 10 among the monovalent chain hydrocarbon groups having 1 to 30 carbon atoms for W in the above formula (1) can be suitably used.
• the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms for W in the above formula (1) can be suitably used.
• the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R 52 As the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R 52 , the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by W in the above formula (1) can be suitably used.
• R 52 is preferably a linear or branched saturated hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 20 carbon atoms.
• the divalent alicyclic group having 3 to 20 carbon atoms constituted by combining the chain hydrocarbon groups or alicyclic hydrocarbon groups represented by R 53 and R 54 together with the carbon atoms to which they are bonded is not particularly limited as long as it is a group in which two hydrogen atoms have been removed from the same carbon atom constituting a carbon ring of a monocyclic or polycyclic alicyclic hydrocarbon having the above carbon number. It may be either a monocyclic hydrocarbon group or a polycyclic hydrocarbon group, and the polycyclic hydrocarbon group may be either a bridged alicyclic hydrocarbon group or a condensed alicyclic hydrocarbon group, or it may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group.
• the condensed alicyclic hydrocarbon group refers to a polycyclic alicyclic hydrocarbon group constituted in such a way that a plurality of alicyclic rings share a side (a bond between two adjacent carbon atoms).
• preferred saturated hydrocarbon groups include cyclopentanediyl, cyclohexanediyl, cycloheptanediyl, and cyclooctanediyl groups
• preferred unsaturated hydrocarbon groups include cyclopentenediyl, cyclohexenediyl, cycloheptenediyl, cyclooctenediyl, and cyclodecenediyl groups.
• Preferred polycyclic alicyclic hydrocarbon groups include bridged alicyclic saturated hydrocarbon groups, such as bicyclo[2.2.1]heptane-2,2-diyl (norbornane-2,2-diyl), bicyclo[2.2.2]octane-2,2-diyl, and tricyclo[3.3.1.1 3,7 ]decane-2,2-diyl (adamantane-2,2-diyl).
• R 52 is an alkyl group having 1 to 4 carbon atoms
• Examples of the substituents that replace some or all of the hydrogen atoms in the hydrocarbon group include the substituents in W in formula (1) above.
• the divalent organic group in L 81 the divalent organic group in R 1 in the above formulae (W-1) to (W-5) can be suitably adopted.
• structural unit (I-1) examples include structural units represented by the following formulas (3-1) to (3-9) (hereinafter also referred to as “structural units (I-1-1) to (I-1-9)").
• R 51 to R 54 have the same meaning as in the above formula (2).
• i and j each independently represent an integer of 1 to 4.
• k and l each represent 0 or 1.
• R 52 is preferably a methyl group, an ethyl group, an isopropyl group, or a cyclopentyl group.
• R 53 and R 54 are preferably a methyl group or an ethyl group.
• X P1 is a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.
• P2 is an integer of 1 to 5, and when P2 is 2 or more, the multiple X P1s may be the same or different from each other.
• X P3 is a hydroxy group, a halogen atom, a carboxy group, a cyano group, a nitro group, an alkyl group, a fluorinated alkyl group, an alkoxycarbonyloxy group, an acyl group, an acyloxy group, or an alkoxy group.
• a1 is an integer of 0 to 3. When a1 is 2 or more, the multiple X P3s are the same or different from each other.
• a2 is an integer of 1 to 3.
• the base polymer may contain one or a combination of two or more types of structural unit (I).
• the lower limit of the content of structural unit (I) (the total content when multiple types are included) relative to all structural units constituting the base polymer is preferably 10 mol%, more preferably 20 mol%, even more preferably 30 mol%, and particularly preferably 35 mol%.
• the upper limit of the content is preferably 80 mol%, more preferably 70 mol%, even more preferably 60 mol%, and particularly preferably 55 mol%.
• the structural unit (II) is a structural unit containing at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure.
• the base polymer further contains the structural unit (II), which allows the base polymer to adjust its solubility in a developer, and as a result, the radiation-sensitive composition can improve lithography performance such as resolution. In addition, the adhesion between a resist pattern formed from the base polymer and a substrate can be improved.
• Examples of the structural unit (II) include structural units represented by the following formulas (T-1) to (T-11).
• R L1 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R L2 to R L5 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a hydroxy group, a hydroxymethyl group, or a dimethylamino group.
• R L4 and R L5 may be combined with each other to form a divalent alicyclic group having 3 to 8 carbon atoms together with the carbon atom to which they are bonded.
• L 2 is a single bond or a divalent linking group.
• X is an oxygen atom or a methylene group.
• k is an integer of 0 to 3.
• m is an integer of 1 to 3.
• Examples of the divalent alicyclic group having 3 to 8 carbon atoms constituted by R L4 and R L5 taken together with the carbon atoms to which they are bonded include divalent alicyclic groups having 3 to 20 carbon atoms constituted by the chain hydrocarbon groups or alicyclic hydrocarbon groups represented by R 53 and R 54 in formula (2) taken together with the carbon atoms to which they are bonded, the divalent alicyclic groups having 3 to 20 carbon atoms being 3 to 8 carbon atoms.
• One or more hydrogen atoms on this alicyclic group may be substituted with a hydroxy group.
• Examples of the divalent linking group represented by L2 above include a divalent linear or branched hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, or a group composed of one or more of these hydrocarbon groups and at least one of -CO-, -O-, -NH-, and -S-.
• structural unit (II) is preferably a structural unit containing a lactone structure, more preferably a structural unit containing a norbornane lactone structure, and even more preferably a structural unit derived from norbornane lactone-yl (meth)acrylate.
• the lower limit of the content of the structural unit (II) is preferably 15 mol%, more preferably 20 mol%, and even more preferably 25 mol%, based on the total structural units constituting the base polymer.
• the upper limit of the content is preferably 80 mol%, more preferably 70 mol%, and even more preferably 65 mol%.
• the base polymer may have other structural units in addition to the structural units (I) and (II).
• the other structural units include a structural unit (III) containing a polar group (excluding the structural unit (II)).
• the base polymer may further have the structural unit (III) to adjust the solubility in the developer, thereby improving the lithography performance such as the resolution of the radiation-sensitive composition.
• the polar group include a hydroxy group, a carboxy group, a cyano group, a nitro group, and a sulfonamide group. Among these, a hydroxy group and a carboxy group are preferred, and a hydroxy group is more preferred.
• structural unit (III) examples include structural units represented by the following formula:
• R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• the lower limit of the content of the structural unit (III) is preferably 2 mol%, more preferably 5 mol%, and even more preferably 8 mol%, based on the total structural units constituting the base polymer.
• the upper limit of the content is preferably 40 mol%, more preferably 30 mol%, and even more preferably 25 mol%.
• the base polymer may have, as other structural units, a structural unit derived from hydroxystyrene or a structural unit having a phenolic hydroxyl group (hereinafter, both of them are also referred to as "structural unit (IV)" collectively) in addition to the structural unit (III) having a polar group.
• the structural unit (IV) contributes to improving the etching resistance and the difference in developer solubility (dissolution contrast) between the exposed and unexposed areas. In particular, it can be suitably applied to pattern formation using exposure to radiation having a wavelength of 50 nm or less, such as electron beams or EUV. In this case, it is preferable that the polymer has the structural unit (I) together with the structural unit (IV).
• Structural units derived from hydroxystyrene are represented, for example, by the following formulas (4-1) to (4-2), and structural units having a phenolic hydroxyl group are represented, for example, by the following formulas (4-3) to (4-4).
• R 61 is each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• Y is a halogen atom, a trifluoromethyl group, a cyano group, an alkyl group or an alkoxy group having 1 to 6 carbon atoms, or an acyl group, an acyloxy group, or an alkoxycarbonyl group having 2 to 7 carbon atoms.
• t is an integer of 0 to 4.
• structural unit (IV) it is preferable to carry out polymerization in a state in which the phenolic hydroxyl group is protected by a protecting group such as an alkali-dissociable group (e.g., an acyl group), and then to obtain structural unit (IV) by deprotecting the phenolic hydroxyl group through hydrolysis.
• a protecting group such as an alkali-dissociable group (e.g., an acyl group
• the lower limit of the content of structural unit (IV) is preferably 10 mol %, more preferably 20 mol %, based on the total structural units constituting the polymer.
• the upper limit of the content is preferably 70 mol %, more preferably 60 mol %.
• the base polymer may contain a structural unit having an alicyclic structure represented by the following formula (6) as a structural unit other than the structural units listed above.
• R 1 ⁇ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R 2 ⁇ is a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms.
• the monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms represented by R 2 ⁇ can be suitably used as the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R 2 ⁇ .
• the monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms represented by R 1 and R 2 in the above formula (1) can be suitably used as the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R 1 and R 2 in the above formula (1).
• the lower limit of the content of the structural unit having the above alicyclic structure is preferably 2 mol%, more preferably 5 mol%, and even more preferably 8 mol%, based on the total structural units constituting the base polymer.
• the upper limit of the content is preferably 30 mol%, more preferably 20 mol%, and even more preferably 15 mol%.
• the base polymer can be synthesized, for example, by polymerizing monomers that provide each structural unit in an appropriate solvent using a radical polymerization initiator or the like.
• the radical polymerization initiator may be an azo radical initiator such as azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), or dimethyl 2,2'-azobisisobutyrate; or a peroxide radical initiator such as benzoyl peroxide, t-butyl hydroperoxide, or cumene hydroperoxide.
• AIBN and dimethyl 2,2'-azobisisobutyrate are preferred, with AIBN being more preferred.
• These radical initiators may be used alone or in combination of two or more.
• solvent used in the polymerization examples include Alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, and norbornane; Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and cumene; Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, and chlorobenzene; Saturated carboxylates such as ethyl acetate, n-butyl acetate, i-butyl acetate, and methyl propionate; Ketones such as acetone, 2-butanone, 4-methyl-2
• the reaction temperature in the above polymerization is usually 40°C to 150°C, preferably 50°C to 120°C.
• the reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours.
• the molecular weight of the base polymer is not particularly limited, but the lower limit of the polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is preferably 2,000, more preferably 3,000, even more preferably 4,000, and particularly preferably 4,500.
• the upper limit of Mw is preferably 30,000, more preferably 20,000, even more preferably 12,000, and particularly preferably 10,000.
• the ratio of Mw to the polystyrene equivalent number average molecular weight (Mn) of the base polymer by GPC 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 polymer in this specification are values measured using gel permeation chromatography (GPC) under the following conditions.
• the content of the base polymer is preferably 60% by mass or more, more preferably 65% by mass or more, and even more preferably 70% by mass or more, based on the total solid content of the radiation-sensitive composition.
• the radiation-sensitive composition of the present embodiment may contain, as the other polymer, a polymer having a higher mass content of fluorine atoms than the base polymer (hereinafter, also referred to as a "high fluorine content polymer".
• the high fluorine content polymer can be unevenly distributed in the surface layer of the resist film relative to the base polymer, and as a result, the water repellency of the surface of the resist film during immersion exposure can be increased, and the surface of the resist film can be modified during EUV exposure, and the distribution of the composition within the film can be controlled.
• the high fluorine content polymer preferably has, for example, a structural unit represented by the following formula (5) (hereinafter also referred to as “structural unit (V)”), and may have structural unit (I) or structural unit (III) in the above base polymer, as necessary.
• R 73 is a hydrogen atom, a methyl group, or a trifluoromethyl group.
• G L is a single bond, an alkanediyl group having 1 to 5 carbon atoms, an oxygen atom, a sulfur atom, -COO-, -OCO-, -SO 2 ONH-, -CONH-, -OCONH-, or a combination thereof.
• R 74 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 73 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.
• G L from the viewpoint of copolymerizability of the monomer that gives the structural unit (V), a combination of at least one of a single bond, -COO-, -COO-, and -OCO- and an alkanediyl group having 1 to 5 carbon atoms is preferable, and -COO- is more preferable.
• Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms represented by R 74 include linear or branched alkyl groups having 1 to 20 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms.
• Examples of the monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R74 include monocyclic or polycyclic hydrocarbon groups having 3 to 20 carbon atoms in which some or all of the hydrogen atoms have been substituted with fluorine atoms.
• R 74 is preferably a fluorinated chain hydrocarbon group, more preferably a fluorinated alkyl group, and further preferably a 2,2,2-trifluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a 1,1,1,3,3,3-hexafluoropropyl group, or a 5,5,5-trifluoro-1,1-diethylpentyl group.
• the lower limit of the content of the structural unit (V) is preferably 40 mol%, more preferably 50 mol%, and even more preferably 55 mol%, based on all structural units constituting the high fluorine content polymer.
• the upper limit of the content is preferably 90 mol%, more preferably 80 mol%, and even more preferably 70 mol%.
• the high fluorine content polymer may have a fluorine atom-containing structural unit represented by the following formula (f-2) (hereinafter also referred to as structural unit (VI)) in addition to or instead of the structural unit (V).
• structural unit (f-2) hereinafter also referred to as structural unit (VI)
• the high fluorine content polymer has improved solubility in an alkaline developer, and the occurrence of development defects can be suppressed.
• the structural unit (VI) is roughly classified into two types: (x) a case having an alkali-soluble group, and (y) a case having a group that dissociates under the action of an alkali to increase the solubility in an alkali developer (hereinafter, also simply referred to as "alkali dissociable group").
• R C is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R D is a single bond, an (s+1)-valent hydrocarbon group having 1 to 20 carbon atoms, a structure in which an oxygen atom, a sulfur atom, -NR dd -, a carbonyl group, -COO-, -OCO-, or -CONH- is bonded to the end of the hydrocarbon group on the R E side, or a structure in which some of the hydrogen atoms of the hydrocarbon group are substituted with an organic group having a hetero atom.
• R dd is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. s is an integer from 1 to 3.
• R F is a hydrogen atom
• a 1 is an oxygen atom, -COO-* or -SO 2 O-*. * indicates the site bonding to R F.
• W 1 is a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or a divalent fluorinated hydrocarbon group.
• a 1 is an oxygen atom
• W 1 is a fluorinated hydrocarbon group having a fluorine atom or a fluoroalkyl group on the carbon atom to which A 1 is bonded.
• R E is a single bond or a divalent organic group having 1 to 20 carbon atoms.
• R E s When s is 2 or 3, a plurality of R E s , W 1 s , A 1 s and R F s may be the same or different.
• the structural unit (VI) has an alkali-soluble group (x), it is possible to increase affinity for an alkaline developer and suppress development defects.
• a 1 is an oxygen atom and W 1 is a 1,1,1,3,3,3-hexafluoro-2,2-methanediyl group.
• RF is a monovalent organic group having 1 to 30 carbon atoms
• a 1 is an oxygen atom, -NR aa -, -COO-*, -OCO-* or -SO 2 O-*.
• R aa is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates the site bonding to RF .
• W 1 is a single bond or a divalent fluorinated hydrocarbon group having 1 to 20 carbon atoms.
• R E is a single bond or a divalent organic group having 1 to 20 carbon atoms.
• W 1 or RF has a fluorine atom on the carbon atom bonding to A 1 or on the carbon atom adjacent thereto.
• a 1 is an oxygen atom
• W 1 and R E are single bonds
• R D is a structure in which a carbonyl group is bonded to the end of a hydrocarbon group having 1 to 20 carbon atoms on the R E side
• R F is an organic group having a fluorine atom.
• s is 2 or 3
• the multiple R E s , W 1 s , A 1 s , and R F s may be the same or different.
• the resist film surface changes from hydrophobic to hydrophilic in the alkali development step.
• the affinity to the developer is significantly increased, and development defects can be more efficiently suppressed.
• a 1 is -COO-*, and R F or W 1 or both of them have a fluorine atom.
• R 3 C is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.
• R 3 E is a divalent organic group, it is preferably a group having a lactone structure, more preferably a group having a polycyclic lactone structure, and even more preferably a group having a norbornane lactone structure.
• the lower limit of the content of the structural unit (VI) is preferably 40 mol%, more preferably 50 mol%, and even more preferably 55 mol%, based on all structural units constituting the high fluorine content polymer.
• the upper limit of the content is preferably 95 mol%, more preferably 90 mol%, and even more preferably 85 mol%.
• the high fluorine content polymer may contain, as a structural unit other than the structural units listed above, a structural unit having an alicyclic structure represented by the above formula (6), in addition to the structural units (I) and (III) in the base polymer.
• the content ratio of each structural unit in the high fluorine content polymer can suitably be the content ratio described for the base polymer.
• the lower limit of the content ratio of the structural unit having the above alicyclic structure is preferably 10 mol%, more preferably 20 mol%, and even more preferably 30 mol%, based on all structural units constituting the high fluorine content polymer.
• the upper limit of the content ratio is preferably 60 mol%, more preferably 50 mol%, and even more preferably 45 mol%.
• the lower limit of the Mw of the high fluorine content polymer is preferably 2,000, more preferably 3,000, even more preferably 4,000, and particularly preferably 5,000.
• the upper limit of the Mw is preferably 30,000, more preferably 20,000, even more preferably 10,000, and particularly preferably 8,000.
• the lower limit of Mw/Mn of the high fluorine content polymer is usually 1, and more preferably 1.1.
• the upper limit of the above Mw/Mn is usually 5, and more preferably 3, and more preferably 2.
• the content of the high-fluorine content polymer is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 1.5 parts by mass or more, and particularly preferably 2 parts by mass or more, relative to 100 parts by mass of the base polymer. Also, the content is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 8 parts by mass or less, and particularly preferably 6 parts by mass or less.
• the radiation-sensitive composition may contain one or more types of high fluorine content polymers.
• the high fluorine content polymer can be synthesized by a method similar to that for synthesizing the base polymer described above.
• the radiation-sensitive composition may contain an acid diffusion controller other than the onium salt compound (1) as the acid diffusion controller, if necessary.
• the acid diffusion controller controls the diffusion phenomenon in the resist film of the acid generated from the onium salt compound (1) as the radiation-sensitive strong acid generator or other radiation-sensitive strong acid generators by exposure, and has the effect of suppressing undesirable chemical reactions in the unexposed areas.
• the storage stability of the obtained radiation-sensitive composition is improved.
• the resolution of the resist pattern is further improved, and the line width change of the resist pattern due to the fluctuation of the delay time from exposure to development processing can be suppressed, and a radiation-sensitive composition with excellent process stability can be obtained.
• acid diffusion control agents include compounds represented by the following formula (7) (hereinafter also referred to as "nitrogen-containing compound (I)”), compounds having two nitrogen atoms in the same molecule (hereinafter also referred to as “nitrogen-containing compound (II)”), compounds having three nitrogen atoms (hereinafter also referred to as “nitrogen-containing compound (III)”), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc.
• R 22 , R 23 and R 24 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group.
• nitrogen-containing compound (I) examples include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine; and aromatic amines such as aniline and 2,6-di-i-propylaniline.
• nitrogen-containing compound (II) examples include ethylenediamine, N,N,N',N'-tetramethylethylenediamine, etc.
• nitrogen-containing compound (III) examples include polyamine compounds such as polyethyleneimine and polyallylamine; polymers such as dimethylaminoethylacrylamide; and the like.
• amide group-containing compounds include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, and N-methylpyrrolidone.
• urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tributylthiourea.
• nitrogen-containing heterocyclic compounds examples include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N-(undecylcarbonyloxyethyl)morpholine; pyrazine, pyrazole, etc.
• nitrogen-containing organic compounds having such an acid-dissociable group include N-t-butoxycarbonylpiperidine, N-t-butoxycarbonylimidazole, N-t-butoxycarbonylbenzimidazole, N-t-butoxycarbonyl-2-phenylbenzimidazole, N-t-amyloxycarbonyl-2-phenylbenzimidazole, N-(t-butoxycarbonyl)di-n-octylamine, N-(t-butoxycarbonyl)diethanolamine, N-(t-butoxycarbonyl)dicyclohexylamine, N-(t-butoxycarbonyl)diphenylamine, N-t-butoxycarbonyl-4-hydroxypiperidine, N-t-butoxycarbonyl-4-acetoxypiperidine, and N-t-amyloxycarbonyl-4-hydroxypiper
• a radiation-sensitive weak acid generator that generates a weak acid upon exposure
• the acid generated by the radiation-sensitive weak acid generator is a weak acid that does not induce dissociation of the acid-dissociable group in the polymer under conditions that dissociate the acid-dissociable group.
• dissociation of the acid-dissociable group refers to dissociation upon post-exposure baking at 110°C for 60 seconds.
• Examples of radiation-sensitive weak acid generators include onium salt compounds that decompose upon exposure to light and lose their ability to control acid diffusion.
• Examples of radiation-sensitive weak acid generators include sulfonium salt compounds represented by the following formula (8-1), iodonium salt compounds represented by the following formula (8-2), and ammonium salt compounds represented by the following formula (8-5).
• Other examples include compounds containing a sulfonium cation and anion in the same molecule represented by the following formula (8-3), and compounds containing an iodonium cation and anion in the same molecule represented by the following formula (8-4). However, these do not include onium salt compounds (1) that serve as acid diffusion control agents.
• J + is a sulfonium cation
• U + is an iodonium cation
• D + is an ammonium cation.
• Examples of the sulfonium cation represented by J + include the sulfonium cations represented by the above formulas (X-1) to (X-4), and examples of the iodonium cation represented by U + include the iodonium cations represented by the above formulas (X-5) to (X-6).
• the ammonium cation represented by D + is preferably represented by N + -(R 50 ) 4.
• Each of the multiple R 50 is independently a hydrogen atom or a monovalent hydrocarbon group.
• the monovalent hydrocarbon group in the above formula (1) can be suitably adopted.
• E - , Q - and V - are each independently an anion represented by OH - , R ⁇ -COO - or R ⁇ -SO 3 - .
• R ⁇ is a single bond or a monovalent organic group having 1 to 30 carbon atoms (however, when the anion is represented by R ⁇ -SO 3 - , no fluorine atom or fluorinated hydrocarbon group is bonded to the carbon atom bonded to the sulfur atom in R ⁇ ).
• this organic group examples include monovalent hydrocarbon groups having 1 to 20 carbon atoms, groups having a divalent heteroatom-containing group between the carbon atoms of this hydrocarbon group or at the carbon chain end, groups in which some or all of the hydrogen atoms of the hydrocarbon group have been substituted with monovalent heteroatom-containing groups, and combinations thereof.
• the monovalent hydrocarbon group having 1 to 20 carbon atoms can be suitably used.
• Heteroatoms constituting the divalent or monovalent heteroatom-containing group include, for example, oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, halogen atoms, etc.
• Halogen atoms include, for example, fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.
• the divalent heteroatom-containing group in the above formula (1) can be suitably used.
• Examples of monovalent heteroatom-containing groups include hydroxyl groups, sulfanyl groups, cyano groups, nitro groups, and halogen atoms.
• onium salt compounds include compounds represented by the following formula:
• the above radiation-sensitive weak acid generators are preferably sulfonium salts, more preferably triarylsulfonium salts, and even more preferably triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate.
• the lower limit of the content of the acid diffusion control agent other than the onium salt compound (1) as the acid diffusion control agent is preferably 0.5 parts by mass, more preferably 1 part by mass, and even more preferably 2 parts by mass, relative to 100 parts by mass of the polymer.
• the upper limit of the content is preferably 30 parts by mass, more preferably 20 parts by mass, and even more preferably 15 parts by mass.
• the radiation-sensitive composition may contain one or more types of acid diffusion controller.
• the radiation-sensitive composition according to the present embodiment contains a solvent.
• the solvent is not particularly limited as long as it is capable of dissolving or dispersing at least the compound (1) and the polymer, and the radiation-sensitive acid generator and other components that are optionally contained therein.
• solvents examples include alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, and hydrocarbon-based solvents.
• Alcohol-based solvents include: Monoalcohol solvents having 1 to 18 carbon atoms, such as isopropanol, 4-methyl-2-pentanol, 3-methoxybutanol, n-hexanol, 2-ethylhexanol, furfuryl alcohol, cyclohexanol, 3,3,5-trimethylcyclohexanol, and diacetone alcohol; Polyhydric alcohol solvents having 2 to 18 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol; Examples of the polyhydric alcohol partially etherified solvents include those obtained by etherifying some of the hydroxy groups of the above-mentioned polyhydric alcohol solvents.
• ether solvents include: Dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether; Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran; Aromatic ring-containing ether solvents such as diphenyl ether and anisole (methyl phenyl ether);
• polyhydric alcohol solvent include polyhydric alcohol ether solvents obtained by etherifying the hydroxyl groups of the above-mentioned polyhydric alcohol solvents.
• ketone solvent examples include chain ketone solvents such as acetone, butanone, and methyl-iso-butyl ketone: Cyclic ketone solvents such as cyclopentanone, cyclohexanone, methylcyclohexanone, etc.: Examples include 2,4-pentanedione, acetonylacetone, and acetophenone.
• amide solvent examples include cyclic amide solvents such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone;
• solvent examples include chain amide solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.
• ester-based solvents include: Monocarboxylate 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, and dipropylene glycol monomethyl ether acetate; Lactone solvents such as ⁇ -butyrolactone and valerolactone; Carbonate solvents such as diethyl carbonate, ethylene carbonate, and propylene carbonate; Examples of the solvent include polyvalent carboxylate diester solvents such as propylene glycol diacetate, methoxytriglycol acetate, diethyl oxalate, ethyl acetoacetate, and diethyl phthalate.
• Monocarboxylate ester solvents such as n-butyl acetate and ethyl lactate
• polyhydric alcohol partial ether acetate solvents such
• hydrocarbon solvent examples include: Aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane;
• solvent examples include aromatic hydrocarbon solvents such as benzene, toluene, di-iso-propylbenzene, and n-amylnaphthalene.
• ester-based solvents and ether-based solvents are preferred, polyhydric alcohol partial ether acetate-based solvents, lactone-based solvents, monocarboxylic acid ester-based solvents and ketone-based solvents are more preferred, and propylene glycol monomethyl ether acetate, ⁇ -butyrolactone, ethyl lactate, cyclohexanone and propylene glycol monomethyl ether are even more preferred.
• the radiation-sensitive composition may contain one or more types of solvents.
• the radiation-sensitive composition may contain other optional components in addition to the above components.
• the other optional components include a crosslinking agent, a localization promoter, a surfactant, an alicyclic skeleton-containing compound, a sensitizer, etc. These other optional components may be used alone or in combination of two or more.
• the radiation-sensitive composition can be prepared, for example, by mixing the onium salt compound (1), the polymer, and if necessary, a high fluorine content polymer, and a solvent in a predetermined ratio. After mixing, the radiation-sensitive composition is preferably filtered, for example, through a filter having a pore size of about 0.05 ⁇ m to 0.40 ⁇ m.
• the solid content concentration of the radiation-sensitive composition is usually 0.1% by mass to 50% by mass, preferably 0.5% by mass to 30% by mass, and more preferably 1% by mass to 20% by mass.
• a pattern forming method includes the steps of: a step (1) of directly or indirectly applying the radiation-sensitive composition to a substrate to form a resist film (hereinafter also referred to as a "resist film forming step”); a step (2) of exposing the resist film to light (hereinafter also referred to as an "exposure step”); and a step (3) of developing the exposed resist film (hereinafter also referred to as the "developing step”).
• the above-mentioned resist pattern forming method uses the above-mentioned radiation-sensitive composition, which can form a resist film that is excellent in sensitivity in the exposure process, LWR, DOF performance, pattern rectangularity, EL, CDU, and pattern circularity, making it possible to form a high-quality resist pattern. Each step is described below.
• a resist film is formed from the radiation-sensitive composition.
• the substrate on which the resist film is formed include conventionally known substrates such as silicon wafers, silicon dioxide, and aluminum-coated wafers.
• an organic or inorganic anti-reflective film disclosed in, for example, JP-B-6-12452 or JP-A-59-93448 may be formed on the substrate.
• the coating method include spin coating, casting coating, and roll coating. After coating, pre-baking (PB) may be performed as necessary to volatilize the solvent in the coating.
• the PB temperature is usually 60° C. to 150° C., and preferably 80° C. to 140° C.
• the PB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.
• the lower limit of the thickness of the resist film formed is preferably 10 nm, more preferably 15 nm, and even more preferably 20 nm.
• the upper limit of the thickness is preferably 500 nm, more preferably 400 nm, and even more preferably 300 nm.
• the lower limit of the thickness may be 100 nm, 150 nm, or 200 nm.
• a protective film for immersion that is insoluble in the immersion liquid may be provided on the resist film formed above in order to avoid direct contact between the immersion liquid and the resist film.
• a solvent-peelable protective film that is peeled off with a solvent before the development step see, for example, JP-A No. 2006-227632
• a developer-peelable protective film that is peeled off simultaneously with development in the development step see, for example, WO2005-069076 and WO2006-035790
• the exposure step is carried out with radiation having a wavelength of 50 nm or less
• the resist film formed in the resist film forming step (1) above is irradiated with radiation through a photomask (or, in some cases, through an immersion liquid such as water) to expose the resist film.
• radiation used for exposure include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, EUV (extreme ultraviolet light), X-rays, and gamma rays; charged particle beams such as electron beams and alpha rays, depending on the line width of the target pattern.
• far ultraviolet light, electron beams, and EUV are preferred
• ArF excimer laser light wavelength 193 nm
• KrF excimer laser light wavelength 248 nm
• electron beams, and EUV are more preferred
• the immersion liquid used include water and fluorine-based inert liquids.
• the immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a temperature coefficient of refractive index as small as possible so as to minimize distortion of the optical image projected onto the film, but when the exposure light source is an ArF excimer laser light (wavelength 193 nm), in addition to the above-mentioned viewpoints, water is preferably used from the viewpoints of ease of acquisition and ease of handling.
• a small proportion of an additive that reduces the surface tension of water and increases its surfactant power may be added. It is preferable that this additive does not dissolve the resist film on the wafer and has a negligible effect on the optical coating on the underside of the lens. Distilled water is preferably used as the water to be used.
• PEB post-exposure bake
• This PEB creates a difference in solubility in the developer between the exposed and unexposed parts.
• the PEB temperature is usually 50°C to 180°C, with 80°C to 130°C being preferred.
• the PEB time is usually 5 seconds to 600 seconds, with 10 seconds to 300 seconds being preferred.
• step (3) above the resist film exposed in the exposure step (2) above is developed. This allows a desired resist pattern to be formed. After development, the resist film is generally washed with a rinse liquid such as water or alcohol, and then dried.
• a rinse liquid such as water or alcohol
• examples of the developer used in the above development include an alkaline aqueous solution in which at least one alkaline compound such as 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, and 1,5-diazabicyclo-[4.3.0]-5-nonene is dissolved.
• TMAH tetramethylammonium hydroxide
• TMAH tetramethylammonium hydroxide
• TMAH 1,8-diazabicyclo-[5.4.0]-7-undecene
• examples of the organic solvent include hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, and alcohol solvents, or solvents containing an organic solvent.
• examples of the organic solvent include one or more of the solvents listed as the solvents for the radiation-sensitive composition described above.
• ether solvents, ester solvents, and ketone solvents are preferred.
• glycol ether solvents are preferred, and ethylene glycol monomethyl ether and propylene glycol monomethyl ether are more preferred.
• ester solvent acetate ester solvents are preferred, and n-butyl acetate and amyl acetate are more preferred.
• the content of the organic solvent in the developer is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more.
• components other than the organic solvent in the developer include water and silicone oil.
• the developer may be either an alkaline developer or an organic solvent developer. It can be selected appropriately depending on whether the desired pattern is a positive type or a negative type.
• Development methods include, for example, a method in which the substrate is immersed in a tank filled with developer for a certain period of time (dip method), a method in which developer is piled up on the substrate surface by surface tension and left to stand for a certain period of time (paddle method), a method in which developer is sprayed onto the substrate surface (spray method), and a method in which developer is continuously dispensed by scanning a developer dispensing nozzle at a constant speed over a substrate rotating at a constant speed (dynamic dispense method).
• dip method a method in which the substrate is immersed in a tank filled with developer for a certain period of time
• paddle method a method in which developer is piled up on the substrate surface by surface tension and left to stand for a certain period of time
• spray method a method in which developer is sprayed onto the substrate surface
• dynamic dispense method a method in which developer is continuously dispensed by scanning a developer dispensing nozzle at a constant speed over a substrate rotating at
• the radiation-sensitive acid generator according to this embodiment is represented by the following formula (1).
• W is an organic group having 3 to 40 carbon atoms and at least one ring structure.
• L is a linking group having a valence of (r+1), and r is an integer from 1 to 3.
• r is 1, both p and q are integers from 1 to 3, and when r is 2 to 3, each of the multiple p's and q's is an integer from 0 to 3.
• M + is a monovalent onium cation.
• the onium salt compound represented by the above formula (1) As the onium salt compound represented by the above formula (1), the onium salt compound (1) in the radiation-sensitive composition can be suitably used.
• Mw Weight average molecular weight
• Mn number average molecular weight
• the start of the dropwise addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours.
• the polymerization solution was cooled with water to 30°C or less.
• the cooled polymerization solution was poured into methanol (2,000 parts by mass), and the precipitated white powder was filtered off.
• the white powder separated by filtration was washed twice with methanol, filtered, and dried at 50° C. for 24 hours to obtain a white powdery polymer (A-1) (yield: 85%).
• the Mw of the polymer (A-1) was 7,100, and the Mw/Mn was 1.61.
• the polymerization solution was cooled with water to 30°C or less.
• the cooled polymerization solution was poured into hexane (2,000 parts by mass), and the precipitated white powder was filtered off.
• the white powder filtered off was washed twice with hexane, filtered off, and dissolved in 1-methoxy-2-propanol (300 parts by mass).
• methanol (500 parts by mass), triethylamine (50 parts by mass) and ultrapure water (10 parts by mass) were added, and hydrolysis reaction was carried out at 70° C. for 6 hours while stirring.
• the polymerization solution was cooled with water to 30°C or lower.
• the solvent was replaced with acetonitrile (400 parts by mass), and then hexane (100 parts by mass) was added and stirred to recover the acetonitrile layer. This operation was repeated three times.
• the solvent was replaced with propylene glycol monomethyl ether acetate to obtain a solution of a high fluorine content polymer (F-1) (yield: 78%).
• the high fluorine content polymer (F-1) had an Mw of 6,200 and an Mw/Mn of 1.77.
• the contents of the structural units derived from (M-1), (M-15) and (M-20) were 20.2 mol %, 9.5 mol % and 70.3 mol %, respectively.
• the above olefin was added with 40.0 mmol of potassium permanganate and 50 g of acetonitrile and stirred at 50°C for 10 hours. After that, a saturated aqueous solution of sodium thiosulfate was added to stop the reaction, and then ethyl acetate was added for extraction and the organic layer was separated. The resulting organic layer was washed with a saturated aqueous solution of sodium chloride and then with water. After drying with sodium sulfate, the solvent was distilled off and the diol was purified by column chromatography to obtain a good yield.
• the above diol was added with 20.0 mmol of 5-acetylsalicylic acid, 2.00 mmol of sulfuric acid, and 50 g of dichloromethane, and stirred at room temperature for 24 hours. Water was then added for dilution, followed by extraction with ethyl acetate, and the organic layer was separated. The resulting organic layer was washed with a saturated aqueous sodium chloride solution, followed by water. After drying with sodium sulfate, the solvent was removed, and the acetal was obtained in good yield by purifying with column chromatography.
• a mixture of acetonitrile and water (1:1 (mass ratio)) was added to the above acetal to make a 1 M solution, and then 40.0 mmol of sodium dithionite and 60.0 mmol of sodium bicarbonate were added and reacted at 70°C for 4 hours.
• a mixture of acetonitrile and water (3:1 (mass ratio)) was added to make a 0.5 M solution.
• 60.0 mmol of hydrogen peroxide and 2.00 mmol of sodium tungstate were added and heated and stirred at 50°C for 12 hours.
• a sodium sulfonate salt compound was obtained by extracting with acetonitrile and distilling off the solvent.
• Example B2 to B9 Synthesis of compounds (B-2) to (B-9)
• Onium salt compounds (1) represented by the following formulae (B-2) to (B-9) were synthesized in the same manner as in Example B1, except that the raw materials and precursors were appropriately changed.
• the above diol was added with 20.0 mmol of 5-formylsalicylic acid, 2.00 mmol of sulfuric acid, and 50 g of dichloromethane, and stirred at room temperature for 24 hours. After dilution with water, ethyl acetate was added for extraction, and the organic layer was separated. The resulting organic layer was washed with a saturated aqueous sodium chloride solution, followed by water. After drying with sodium sulfate, the solvent was removed, and the acetal was purified by column chromatography to obtain it in good yield.
• a mixture of acetonitrile and water (1:1 (mass ratio)) was added to the above acetal to make a 1 M solution, and then 40.0 mmol of sodium dithionite and 60.0 mmol of sodium bicarbonate were added and reacted at 70°C for 4 hours.
• a mixture of acetonitrile and water (3:1 (mass ratio)) was added to make a 0.5 M solution.
• 60.0 mmol of hydrogen peroxide and 2.00 mmol of sodium tungstate were added and heated and stirred at 50°C for 12 hours.
• a sodium sulfonate salt compound was obtained by extracting with acetonitrile and distilling off the solvent.
• the onium salt was added with a mixture of methanol and water (1:1 (mass ratio)) to make a 1M solution, and then 20.0 mmol of lithium hydroxide was added and reacted at room temperature for 2 hours. After that, 2M hydrochloric acid was added to stop the reaction, and methylene chloride was added for extraction and the organic layer was separated. The resulting organic layer was dried over sodium sulfate, the solvent was removed, and the solution was purified by column chromatography to obtain compound (B-11-1) represented by the above formula (B-11-1) in good yield.
• the above compound (B-11-1) was added with 20.0 mmol of 4-(2-hydroxyethoxy)salicylic acid, 20.0 mmol of dicyclohexylcarbodiimide, 2.0 mmol of 4-dimethylaminopyridine, and 50 g of methylene chloride, and stirred at room temperature for 3 hours. After that, the mixture was diluted with 1 M hydrochloric acid, extracted with methylene chloride, and the organic layer was separated. The obtained organic layer was washed with a saturated aqueous sodium chloride solution and then with water. After drying with sodium sulfate, the solvent was distilled off, and the mixture was purified by column chromatography to obtain the compound (B-11) represented by the above formula (B-11) in moderate yield.
• Example D2 Synthesis of compound (D-2)
• An acid diffusion controller represented by the following formula (D-2) was synthesized in the same manner as in Example D1, except that the raw materials and precursors were appropriately changed.
• Example D4 (Synthesis of compound (D-4)) An acid diffusion controller represented by the following formula (D-4) was synthesized in the same manner as in Example D3, except that the raw materials and precursors were appropriately changed.
• a radiation-sensitive composition (J-1) was prepared by mixing 100 parts by mass of (A-1) as a polymer [A] and filtering the mixture through a membrane filter having a pore size of 0.2 ⁇ m.
• a composition for forming a bottom anti-reflective coating (“ARC66” from Brewer Science) was applied onto a 12-inch silicon wafer using a spin coater ("CLEAN TRACK ACT12" from Tokyo Electron Co., Ltd.), and then heated at 205° C. for 60 seconds to form a bottom anti-reflective coating having an average thickness of 100 nm.
• the positive radiation-sensitive composition for ArF exposure prepared above was applied onto this bottom anti-reflective coating using the spin coater, and PB (pre-baking) was performed at 100° C. for 60 seconds. Thereafter, the coating was cooled at 23° C.
• PEB post-exposure bake
• the resist film was subjected to alkaline development using a 2.38 mass % TMAH aqueous solution as an alkaline developer, and after development, the resist film was washed with water and further dried to form a positive resist pattern (60 nm line and space pattern).
• sensitivity In forming a resist pattern using the positive-tone radiation-sensitive composition for ArF immersion exposure, the exposure dose required to form a 60 nm line-and-space pattern was determined as the optimum exposure dose, and this optimum exposure dose was determined as the sensitivity (mJ/ cm2 ). Sensitivity was evaluated as "good” when it was 30 mJ/ cm2 or less, and “poor” when it exceeded 30 mJ/ cm2 .
• LWR LWR
• a 60 nm line and space resist pattern was formed by irradiating the optimal exposure dose obtained by the above sensitivity evaluation.
• the formed resist pattern was observed from above the pattern using the above scanning electron microscope.
• a total of 500 points of line width variation were measured, and a 3 sigma value was obtained from the distribution of the measured values, and this 3 sigma value was taken as LWR (nm).
• the smaller the LWR value the smaller the line roughness and the better it was.
• LWR was evaluated as "good” when it was 2.5 nm or less, and as “poor” when it exceeded 2.5 nm.
• the 60 nm line and space resist pattern formed by irradiating with the optimum exposure dose obtained in the above sensitivity evaluation was observed using the above scanning electron microscope, and the cross-sectional shape of the line and space pattern was evaluated.
• the rectangularity of the resist pattern was evaluated as "A” (very good) if the ratio of the length of the lower side to the length of the upper side in the cross-sectional shape was 1 or more and 1.05 or less, "B” (good) if it was more than 1.05 and 1.10 or less, and "C” (poor) if it was more than 1.10.
• the resist film was exposed to an optimal exposure dose to form a line and space pattern with a line width of 60 nm, which was used as a wafer for defect inspection.
• the number of defects on this wafer for defect inspection was measured using a defect inspection device (KLA-Tencor's "KLA2810"). Defects with a diameter of 50 ⁇ m or less were determined to be originating from the resist film, and the number of defects was calculated. The number of defects after development was evaluated as "good” when the number of defects determined to be originating from the resist film was 30 or less, and as “poor” when the number of defects exceeded 30.
• a radiation-sensitive composition (J-50) was prepared by mixing 100 parts by mass of [A] (A-12) as a polymer, 30.0 parts by mass of [B] (B-1) as an onium salt compound (1) (radiation-sensitive acid generator), 20.0 parts by mass of [D] (d-1) as an acid diffusion controller, 5.0 parts by mass (solid content) of [F] (F-5) as a high fluorine content polymer, and 6,000 parts by mass of a mixed solvent of (E-1)/(E-2)/(E-3) as a solvent, and filtering the mixture through a membrane filter having a pore size of 0.2 ⁇ m.
• a composition for forming a bottom anti-reflective coating (“ARC66” by Brewer Science) was applied onto a 12-inch silicon wafer using a spin coater ("CLEAN TRACK ACT12" by Tokyo Electron Co., Ltd.), and then heated at 205° C. for 60 seconds to form a bottom anti-reflective coating having an average thickness of 105 nm.
• the positive-tone radiation-sensitive composition for EUV exposure prepared above was applied onto this bottom anti-reflective coating using the spin coater, and PB was performed at 130° C. for 60 seconds. Thereafter, the coating was cooled at 23° C.
• sensitivity In forming a resist pattern using the positive-tone radiation-sensitive composition for EUV exposure, the exposure dose required to form a 25 nm line-and-space pattern was determined as the optimum exposure dose, and this optimum exposure dose was determined as the sensitivity (mJ/ cm2 ). Sensitivity was evaluated as "good” when it was 40 mJ/ cm2 or less, and “poor” when it exceeded 40 mJ/ cm2 .
• LWR A resist pattern was formed by adjusting the mask size so that the optimum exposure dose obtained in the above sensitivity evaluation was applied to form a 25 nm line and space pattern.
• the formed resist pattern was observed from above the pattern using the above scanning electron microscope.
• a total of 500 points of line width variation were measured, and a 3 sigma value was calculated from the distribution of the measured values, and this 3 sigma value was taken as LWR (nm).
• the smaller the LWR value the smaller the line wobble and the better it was.
• the resist film was exposed to an optimal exposure dose to form a line and space pattern with a line width of 25 nm, which was used as a wafer for defect inspection.
• the number of defects on this wafer for defect inspection was measured using a defect inspection device (KLA-Tencor's "KLA2810"). Defects with a diameter of 50 ⁇ m or less were determined to be originating from the resist film, and the number of defects was calculated. The number of defects after development was evaluated as "good” when the number of defects determined to be originating from the resist film was 50 or less, and as “poor” when the number of defects exceeded 50.
• EL was evaluated as "good” when it was 7% or more, and as “poor” when it was below 7%.
• the radiation-sensitive compositions of the Examples had good sensitivity, LWR, EL, and development defect performance when used for EUV exposure, whereas the Comparative Examples had inferior properties compared to the Examples.
• a radiation-sensitive composition (J-66) was prepared by mixing 100 parts by mass of (A-8) as a polymer [A], 8.0 parts by mass of (B-1) as an onium salt compound (1) (radiation-sensitive acid generator), [D] 7.0 parts by mass of (d-2) as an acid diffusion controller, [F] 2.0 parts by mass (solid content) of (F-4) as a high fluorine content polymer, and 3,230 parts by mass of a mixed solvent of (E-1)/(E-2)/(E-3) (mass ratio 2,240/960/30) as a solvent, and filtering the mixture through a membrane filter having a pore size of 0.2 ⁇ m.
• a composition for forming a bottom anti-reflective coating (Brewer Science's ARC66) was applied onto a 12-inch silicon wafer using a spin coater (Tokyo Electron Limited's CLEAN TRACK ACT12), and then heated at 205°C for 60 seconds to form a bottom anti-reflective coating with an average thickness of 100 nm.
• the negative-tone radiation-sensitive composition for ArF exposure (J-66) prepared above was applied onto this bottom anti-reflective coating using the spin coater, and a PB (pre-bake) was performed at 100°C for 60 seconds. The wafer was then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 90 nm.
• ASML's "TWINSCAN XT-1900i” ArF excimer laser immersion exposure system
• NA 1.35
• the sensitivity of the resist pattern using the negative-tone radiation-sensitive composition for ArF exposure was evaluated in the same manner as the evaluation of the resist pattern using the positive-tone radiation-sensitive composition for ArF exposure.
• the CDU and pattern circularity were evaluated according to the following methods.
• CDU The optimum exposure dose obtained in the above sensitivity evaluation was applied to form 50 nm holes and 100 nm pitch contact holes.
• the formed resist pattern was observed from above the pattern using the above scanning electron microscope.
• a total of 500 points of variation in the contact holes were measured, and a 3 sigma value was calculated from the distribution of the measured values, and this 3 sigma value was taken as CDU (nm).
• the smaller the CDU value the smaller the hole roughness and the better it was.
• CDU was evaluated as "good” when it was less than 3.5 nm, and as "bad” when it was 3.5 nm or more.
• the radiation-sensitive composition of Example 66 had good sensitivity, CDU, and pattern circularity, even when a negative resist pattern was formed by ArF exposure.
• a radiation-sensitive composition (J-67) was prepared by mixing 100 parts by mass of (A-13) as a polymer [A], 30.0 parts by mass of (B-5) as an onium salt compound (1) (radiation-sensitive acid generator), 15.0 parts by mass of (d-4) as an acid diffusion controller, [D] 2.0 parts by mass (solid content) of (F-5) as a high fluorine content polymer, and 6,000 parts by mass of a mixed solvent of (E-1)/(E-2)/(E-3) (mass ratio 1,000/4,900/100) as a solvent, and filtering the mixture through a membrane filter having a pore size of 0.2 ⁇ m.
• a composition for forming a bottom anti-reflective coating (Brewer Science's ARC66) was applied to a 12-inch silicon wafer using a spin coater (Tokyo Electron Limited's CLEAN TRACK ACT12), and then heated at 205°C for 60 seconds to form a bottom anti-reflective coating with an average thickness of 105 nm.
• the negative radiation-sensitive composition for EUV exposure (J-67) prepared above was applied to this bottom anti-reflective coating using the spin coater, and PB was performed at 130°C for 60 seconds. After that, a resist film with an average thickness of 55 nm was formed by cooling at 23°C for 30 seconds.
• EUV exposure device ASML's NXE3300
• NA 0.33
• mask imecDEFECT32FFR15.
• PEB was performed at 120°C for 60 seconds.
• the resist film was then developed with n-butyl acetate as an organic solvent developer and dried to form a negative resist pattern (contact hole pattern with 20 nm holes and 40 nm pitch).
• the resist pattern using the negative-type radiation-sensitive composition for EUV exposure was evaluated in the same manner as the resist pattern using the negative-type radiation-sensitive composition for ArF exposure.
• the radiation-sensitive composition of Example 67 had good sensitivity, CDU, and pattern circularity, even when a negative-type resist pattern was formed by EUV exposure.
• the radiation-sensitive composition and resist pattern forming method described above can form a resist pattern that has good sensitivity to exposure light and is excellent in LWR, pattern rectangularity, development defect performance, EL, CDU, and pattern circularity. Therefore, these can be suitably used in the processing of semiconductor devices, which are expected to become even more miniaturized in the future.

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