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
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
  • C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
  • C07D307/04—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
  • C07D307/10—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having no double bonds between ring members or between ring members and non-ring members with substituted hydrocarbon radicals attached to ring carbon atoms
  • C07D307/12—Radicals substituted by oxygen atoms
• • 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
• • 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
  • C07D327/06—Six-membered rings
  • C07D327/08—[b,e]-condensed with two six-membered carbocyclic rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/02—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
  • C07D333/46—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings substituted on the ring sulfur atom
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/50—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom condensed with carbocyclic rings or ring systems
  • C07D333/76—Dibenzothiophenes
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D335/00—Heterocyclic compounds containing six-membered rings having one sulfur atom as the only ring hetero atom
  • C07D335/04—Heterocyclic compounds containing six-membered rings having one sulfur atom as the only ring hetero atom condensed with carbocyclic rings or ring systems
  • C07D335/10—Dibenzothiopyrans; Hydrogenated dibenzothiopyrans
  • C07D335/12—Thioxanthenes
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D339/00—Heterocyclic compounds containing rings having two sulfur atoms as the only ring hetero atoms
  • C07D339/08—Six-membered rings
• • 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
  • G03F7/0045—Photosensitive materials with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/20—Exposure; Apparatus therefor
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P76/00—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography
  • H10P76/20—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography of masks comprising organic materials
  • H10P76/204—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography of masks comprising organic materials of organic photoresist masks
  • H10P76/2041—Photolithographic processes

Definitions

• a radiation-sensitive composition is irradiated with far ultraviolet light (such as an ArF excimer laser), extreme ultraviolet light (EUV), electron beams, etc. to generate acid in the exposed areas, and a chemical reaction involving this acid creates a difference in the dissolution rate in the developer between the exposed and unexposed areas, forming a resist pattern on the substrate.
• far ultraviolet light such as an ArF excimer laser
• EUV extreme ultraviolet light
• electron beams etc.
• the present disclosure has been made in consideration of the above problems, and its purpose is to provide a radiation-sensitive composition that has high sensitivity and good LWR performance while ensuring storage stability, and a method for forming a resist pattern using the radiation-sensitive composition.
• the present disclosure provides a radiation-sensitive composition that contains [A] a polymer having a hydroxyl group bonded to an aromatic ring, and [B] a radiation-sensitive acid generator consisting of a cation and a sulfonate anion, wherein the cation of the radiation-sensitive acid generator [B] has a fluorine atom, and the sulfonate anion of the radiation-sensitive acid generator [B] has an aromatic ring (Ia) to which an iodine atom is bonded and an aromatic ring (IIa) to which an acidic functional group is bonded, wherein no acidic functional group is bonded to the aromatic ring (Ia), and no iodine atom is bonded to the aromatic ring (IIa).
• the present disclosure provides a method for forming a resist pattern, comprising the steps of forming a resist film on a substrate using the radiation-sensitive composition, exposing the resist film to light, and developing the exposed resist film.
• a radiation-sensitive acid generator comprising a cation and a sulfonate anion, the cation having a fluorine atom, the sulfonate anion having an aromatic ring to which an iodine atom is bonded and an aromatic ring to which an acidic functional group is bonded, the aromatic ring to which the iodine atom is bonded has no acidic functional group bonded, and the aromatic ring to which the acidic functional group is bonded has no iodine atom bonded.
• the radiation-sensitive composition of the present disclosure (hereinafter also referred to as “the composition”) contains a polymer (A) and a radiation-sensitive acid generator (B).
• A a polymer
• B a radiation-sensitive acid generator
• [C] another acid generator a compound that is different from the radiation-sensitive acid generator and generates an acid upon exposure
• [D] a solvent a solvent
• F high fluorine content polymers
• hydrocarbon group includes linear hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups.
• linear hydrocarbon group refers to linear and branched hydrocarbon groups that do not contain a cyclic structure and are composed only of a linear structure. However, the linear hydrocarbon group may be saturated or unsaturated.
• alicyclic hydrocarbon group refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. However, the alicyclic hydrocarbon group does not have to be composed only of an alicyclic hydrocarbon structure and includes those that have a linear structure as part of it.
• substituted or unsubstituted p-valent hydrocarbon group (where p is an integer of 1 or more) includes p-valent hydrocarbon groups (i.e., unsubstituted p-valent hydrocarbon groups) and groups in which p hydrogen atoms have been removed from the hydrocarbon structural portion of a substituted hydrocarbon group.
• the polymer [A] has a hydroxyl group bonded to an aromatic ring.
• the polymer [A] has a hydroxyl group bonded to an aromatic ring, which is preferable in that the lithography properties of the composition, such as LWR performance and CDU (Critical Dimension Uniformity) performance, can be further improved, and the effect of suppressing dissolution of unexposed areas into a developer can be highly suppressed, sufficiently reducing development defects.
• a polymer having a hydroxyl group bonded to an aromatic ring can be preferably applied in pattern formation using exposure to radiation with a wavelength of 50 nm or less, such as electron beams or EUV.
• Examples of the aromatic ring to which the hydroxyl group is bonded include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. Of these, a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.
• the number of hydroxyl groups bonded to the aromatic ring is preferably 1 to 3, and more preferably 1 or 2.
• the position of the hydroxyl group in the benzene ring may be any of the ortho, meta, and para positions relative to other groups.
• the aromatic ring to which the hydroxyl group is bonded may further have a substituent different from the hydroxyl group bonded thereto.
• substituents include alkyl groups having 1 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, halogen atoms (e.g., fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), etc.
• the polymer [A] contains a structural unit having a hydroxyl group bonded to an aromatic ring (hereinafter also referred to as the "first structural unit").
• a preferred specific example of the first structural unit is a structural unit represented by the following formula (i).
• R 11 is a hydrogen atom, a fluoro group, a methyl group, or a trifluoromethyl group.
• L 2 is a single bond, -O-, -CO-, -COO-, or -CONH-.
• a 1 is a group in which (s1+s2) hydrogen atoms have been removed from an aromatic ring.
• B 1 is a monovalent substituent other than a hydroxyl group, a group having an acid dissociable group, and a group having an onium salt structure.
• s1 is an integer of 1 or more.
• s2 is an integer of 0 or more.
• R 11 is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerizability of the monomer that provides the first structural unit
• L 2 is preferably a single bond or -COO-.
• the aromatic ring in A 1 is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring.
• the aromatic ring in A 1 may further have a substituent different from a hydroxyl group, a group having an acid dissociable group, and a group having an onium salt structure. Specific examples of the substituent are as described above.
• s1 is preferably 1 to 3, and more preferably 1 or 2.
• s2 is preferably 0 to 3, and more preferably 0 to 2, and further preferably 0 or 1.
• the polymer [A] may contain a structural unit having a partial structure in which a hydroxyl group and an acid-dissociable group are bonded to the same or different aromatic rings.
• a structural unit having a partial structure in which a hydroxyl group and an acid-dissociable group are bonded to the same or different aromatic rings is classified as a structural unit different from the first structural unit (specifically, the second structural unit shown below).
• the polymer [A] may contain a structural unit having a partial structure in which an onium salt structure and a hydroxyl group are bonded to the same or different aromatic rings.
• a structural unit having a partial structure in which an onium salt structure and a hydroxyl group are bonded to the same or different aromatic rings is classified as a structural unit different from the first structural unit (specifically, the third structural unit shown below).
• R 11 is a hydrogen atom, a fluoro group, a methyl group, or a trifluoromethyl group.
• the polymer (A) preferably contains, as the first structural unit, a structural unit represented by the following formula (i-1) or (i-2).
• R 11 is a hydrogen atom, a fluoro group, a methyl group, or a trifluoromethyl group.
• L 2 is a single bond, -O-, -CO-, -COO-, or -CONH-.
• R 41 is a monovalent substituent different from a hydroxyl group, a group having an acid dissociable group, and a group having an onium salt structure.
• r1 is an integer of 0 to 4.
• examples of the monovalent substituent represented by R41 include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a halogen atom, etc.
• r1 is preferably 0 to 2, and more preferably 0 or 1.
• the content of the first structural unit is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 15 mol% or more, based on all structural units constituting the polymer [A].
• the content of the first structural unit is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less, based on all structural units constituting the polymer [A].
• a polymer having a hydroxyl group bonded to an aromatic ring for example, this may be carried out by polymerization using a monomer having a hydroxyl group bonded to an aromatic ring.
• the hydroxyl group e.g., a phenolic hydroxyl group
• the hydroxyl group may be protected by a protecting group such as an alkali-dissociable group during polymerization, and then hydrolysis may be carried out to remove the protection, thereby obtaining a polymer having a hydroxyl group bonded to an aromatic ring.
• the polymer (A) may further include a structural unit (hereinafter, also referred to as "other structural unit") different from the first structural unit.
• other structural unit include the second to fifth structural units shown below.
• the polymer [A] may contain a structural unit having an acid dissociable group (hereinafter referred to as the "second structural unit").
• the acid dissociable group of the second structural unit is preferably a group that replaces a hydrogen atom of an acid group such as a carboxy group or a hydroxyl group, and is a group that dissociates under the action of an acid.
• the acid dissociable group in the second structural unit dissociates due to the acid generated by exposure of the composition to light to generate an acid group, and the solubility of the polymer [A] in a developer changes, thereby imparting good lithography properties to the composition.
• Examples of the second structural unit include a structural unit represented by the following formula (ii-1) (hereinafter also referred to as “structural unit (II-1)”), a structural unit represented by the following formula (ii-2) (hereinafter also referred to as “structural unit (II-2)”), and a structural unit represented by the following formula (ii-3) (hereinafter also referred to as “structural unit (II-3)").
• R 12 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• R 13 is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
• R 14 and R 15 are each independently a substituted or unsubstituted monovalent hydrocarbon group or aromatic heterocyclic group having 1 to 20 carbon atoms, or R 14 and R 15 taken together represent an alicyclic hydrocarbon structure having 3 to 20 carbon atoms together with the carbon atoms to which R 14 and R 15 are bonded.
• R 13 is a hydrogen atom
• R 14 and R 15 are each independently a monovalent unsaturated hydrocarbon group or aromatic heterocyclic group
• R 14 and R 15 taken together represent an unsaturated alicyclic hydrocarbon structure having 3 to 20 carbon atoms together with the carbon atoms to which R 14 and R 15 are bonded.
• R 16 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• L 3 is a single bond, -O-, -CO-, -COO- or -CONH-.
• R 17 , R 18 and R 19 are each independently a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a substituted or unsubstituted monovalent oxyhydrocarbon group having 1 to 20 carbon atoms.
• R 35 is a monovalent substituent.
• g1 is an integer of 0 to 4.
• R 31 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• L 4 is a single bond, -O-, -CO-, -COO-, or -CONH-.
• R 32 is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a substituted or unsubstituted monovalent oxyhydrocarbon group having 1 to 20 carbon atoms.
• R 33 and R 34 are each independently a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a substituted or unsubstituted monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, or R 33 and R 34 taken together represent an alicyclic hydrocarbon structure having 3 to 20 carbon atoms formed together with the carbon atom to which R 33 and R 34 are bonded.
• R 36 is a monovalent substituent.
• g2 is an integer of 0 to 4.
• R 12 is preferably a hydrogen atom or a methyl group, more preferably a methyl group, from the viewpoint of copolymerizability of the monomer that gives the structural unit (II-1).
• R 16 is preferably a hydrogen atom, from the viewpoint of copolymerizability of the monomer that gives the structural unit (II-2).
• R 31 in the above formula (ii-3) is preferably a hydrogen atom or a methyl group.
• L 3 in the above formula (ii-2) or L 4 in the above formula (ii-3) is preferably a single bond, -COO- or -CONH-.
• Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 13 to R 15 , R 17 to R 19 or R 32 to R 34 include a monovalent chain hydrocarbon group having 1 to 20 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.
• Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, and t-butyl; alkenyl groups such as ethenyl, propenyl, and butenyl; and alkynyl groups such as ethynyl, propynyl, and butynyl.
• the monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R 13 to R 15 , R 17 to R 19 , or R 32 to R 34 is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms.
• Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monovalent monocyclic alicyclic saturated hydrocarbon groups such as cyclopentyl, cyclohexyl, methylcyclopentyl, ethylcyclopentyl, methylcyclohexyl, and ethylcyclohexyl groups; monovalent monocyclic unsaturated hydrocarbon groups such as cyclopentenyl, cyclohexenyl, methylcyclopentenyl, and methylcyclohexenyl groups; monovalent polycyclic saturated alicyclic hydrocarbon groups such as norbornyl, adamantyl, and tricyclodecyl groups; and monovalent polycyclic unsaturated alicyclic hydrocarbon groups such as norbornenyl, tricyclodecenyl, and indanyl groups.
• monovalent monocyclic alicyclic saturated hydrocarbon groups such as cyclopentyl, cyclohexyl, methylcyclopen
• Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthryl, methylanthryl, and indenyl; and aralkyl groups such as benzyl, phenethyl, naphthylmethyl, and anthrylmethyl.
• Examples of the alicyclic hydrocarbon structure having 3 to 20 carbon atoms formed by combining R 14 and R 15 together with the carbon atoms to which R 14 and R 15 are bonded, and the alicyclic hydrocarbon structure having 3 to 20 carbon atoms formed by combining R 33 and R 34 together with the carbon atoms to which R 33 and R 34 are bonded include monocyclic saturated alicyclic hydrocarbon structures such as a cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, cycloheptane structure, and cyclooctane structure; monocyclic unsaturated alicyclic hydrocarbon structures such as cyclopentene and cyclohexene; and polycyclic alicyclic hydrocarbon structures such as a norbornane structure, adamantane structure, tricyclodecane structure, and tetracyclododecane structure.
• monocyclic saturated alicyclic hydrocarbon structures such as a
• Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms represented by R 17 to R 19 or R 32 to R 34 include groups containing an oxygen atom at the bond-side terminal of the above-mentioned examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 13 to R 15 , R 17 to R 19 , and R 32 to R 34.
• the monovalent oxyhydrocarbon group represented by R 17 to R 19 or R 32 to R 34 is preferably an alkoxy group, a cycloalkoxy group, or a cycloalkylalkoxy group.
• R 13 to R 15 , R 17 to R 19 or R 32 to R 34 have a substituent
• substituents include a halogen atom, a hydroxyl group, an alkoxy group having 1 to 3 carbon atoms, etc.
• R 14 and R 15 are combined with each other to form an alicyclic hydrocarbon structure having 3 to 20 carbon atoms together with the carbon atom to which R 14 and R 15 are bonded
• R 33 and R 34 are combined with each other to form an alicyclic hydrocarbon structure having 3 to 20 carbon atoms together with the carbon atom to which R 33 and R 34 are bonded
• the above-exemplified substituents or alkyl groups may be bonded to the ring.
• Examples of the monovalent substituent represented by R 35 or R 36 include an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), etc.
• g1 and g2 are preferably 0 to 2, and more preferably 0 or 1.
• structural unit (II-1) include structural units represented by the following formulas: (In the formula, R 12 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)
• R 16 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• structural unit (II-3) include structural units represented by the following formulas: (In the formula, R 31 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)
• the content of the second structural unit is preferably 20 mol% or more, more preferably 25 mol% or more, and even more preferably 30 mol% or more, based on the total structural units constituting the polymer [A].
• the content of the second structural unit is preferably 80 mol% or less, more preferably 75 mol% or less, and even more preferably 70 mol% or less, based on the total structural units constituting the polymer [A].
• the present composition may contain a polymer containing a second structural unit in addition to the polymer containing the first structural unit.
• the present composition preferably contains, as polymer [A], a polymer having the first structural unit and the second structural unit in the same molecule.
• the polymer [A] may contain a structural unit having an onium salt structure (this will be referred to as the "third structural unit").
• the third structural unit preferably has a partial structure in which an iodine atom is bonded to an aromatic ring (preferably a benzene ring), and more preferably contains an iodoaryl ring.
• the number of iodine atoms bonded to the aromatic ring is, for example, 1 to 5.
• the iodine atom may be contained in the radiation-sensitive onium cation portion constituting the onium salt structure, or in the organic anion portion, or in both of them.
• the third structural unit is typically a structural unit derived from an onium salt compound having a group involved in polymerization.
• the polymer [A] contains such a structural unit, the effect of reducing development residues can be enhanced, and lithography properties can be improved.
• the third structural unit include a structural unit represented by the following formula (iv-1), a structural unit represented by the following formula (iv-2), and a structural unit represented by the following formula (iv-3).
• R 20 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• L 5 is a single bond, -O-, or -COO-.
• R 23 is a substituted or unsubstituted alkanediyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkenediyl group having 2 to 6 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 12 carbon atoms.
• R 21 and R 22 are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
• J - is a monovalent anion.
• R 20 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• L 6 is a single bond, **-R 30a -CO-O-, **-R 30a -O-, or **-R 30a -O-CO- (wherein "**" represents a bond to an oxygen atom).
• R 30a is a divalent group containing -O-, -CO-, or -COO- between the carbon-carbon bonds of a substituted or unsubstituted alkanediyl group having 1 to 12 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted aralkylene group having 6 to 12 carbon atoms, or a divalent group containing -O-, -CO-, or -COO- between the carbon-carbon bonds of a substituted or unsubstituted aralkylene group having 6 to 12 carbon atoms.
• R 24 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group having 1 to 10 carbon atoms.
• Y + is a monovalent cation.
• R 20 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.
• L 7 is a single bond, a substituted or unsubstituted alkanediyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkenediyl group having 2 to 6 carbon atoms, a substituted or unsubstituted arylene group having 6 to 12 carbon atoms, a substituted or unsubstituted aralkylene group having 6 to 12 carbon atoms, **-CO-O-R 30b -, or **-CO-NH-R 30b - (wherein "**" represents a bond to the carbon atom to which R 20 is bonded).
• R 30b is a divalent group containing -O-, -CO- or -COO- between the carbon-carbon bonds of a substituted or unsubstituted alkanediyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aralkylene group having 6 to 12 carbon atoms, or a divalent group containing -O-, -CO- or -COO- between the carbon-carbon bonds of a substituted or unsubstituted aralkylene group having 6 to 12 carbon atoms.
• R 25 is a single bond, ***-CO-O-R 26 -, ***-O-CO-R 26 -, ***-NH-CO-R 26 -, ***-CO-NH-R 26 -, or ***-O-NH-R 26 - (wherein "***" represents a bond to L 7 ).
• R 26 is a substituted or unsubstituted alkanediyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkenediyl group having 2 to 6 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 12 carbon atoms.
• Y + is a monovalent cation.
• R 21 and R 22 when each of R 21 and R 22 is a substituted alkyl group, a substituted alkenyl group, or a substituted aryl group, and when each of R 23 , R 30a , R 30b , L 7 , and R 26 is a substituted alkanediyl group, a substituted alkenediyl group, or a substituted arylene group, examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkoxy group, a cycloalkyloxy group, an ester group, an alkylsulfonyl group, a cycloalkylsulfonyl group, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an acetyl group, and a fluoroacetyl group.
• the cation (Y + ) in formula (iv-2) and formula (iv-3) preferably has a triarylsulfonium cationic structure or a diaryliodonium cationic structure.
• the cation (Y + ) has a triarylsulfonium cationic structure or a diaryliodonium cationic structure, and that a fluoro group or a fluoroalkyl group is bonded to an aromatic ring in the triarylsulfonium cationic structure or diaryliodonium cationic structure (i.e., the aromatic ring bonded to S + or I + ).
• the fluoroalkyl group is preferably a trifluoromethyl group.
• one or more of L 5 , R 21 , R 22 , R 23 and J ⁇ in formula (iv-1) have an iodine atom.
• one or more of L 6 and Y + in formula (iv-2) have an iodine atom
• the third structural unit include structural units represented by the following formulas (iva-1) to (iva-5).
• R 20 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.
• Y 1 + is a monovalent cation.
• the content of the third structural unit is preferably 1 mol % or more, and more preferably 3 mol % or more, based on all structural units constituting the polymer [A].
• the content of the third structural unit is preferably 40 mol % or less, and more preferably 30 mol % or less, based on all structural units constituting the polymer [A].
• the polymer [A] may contain a structural unit having an onium salt structure and a hydroxyl group bonded to an aromatic ring.
• a structural unit having an onium salt structure and a hydroxyl group bonded to an aromatic ring (for example, a structural unit represented by the above formula (iva-3)) is classified as a third structural unit.
• the polymer [A] may also contain a structural unit having an onium salt structure and an acid dissociable group. In this specification, a structural unit having an onium salt structure and an acid dissociable group is classified as a third structural unit.
• the polymer [A] may contain a structural unit having a lactone structure, a cyclic carbonate structure, a sultone structure, or a ring structure combining two or more of these (excluding the first structural unit, the second structural unit, and the third structural unit. This is referred to as the "fourth structural unit").
• the solubility in the developer can be adjusted, and as a result, the lithography properties of the composition can be further improved, which is preferable.
• the adhesion between the resist film obtained by using the composition and the substrate can be improved.
• Examples of the fourth structural unit include a structural unit represented by the following formula. (In the formula, R L1 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)
• the content of the fourth structural unit is preferably 1 mol % or more, and more preferably 3 mol % or more, based on all structural units constituting the polymer [A].
• the content of the fourth structural unit is preferably 30 mol % or less, more preferably 20 mol % or less, and even more preferably 15 mol % or less, based on all structural units constituting the polymer [A].
• the polymer [A] may further have a structural unit having an alcoholic hydroxyl group (excluding the first structural unit, the second structural unit, the third structural unit and the fourth structural unit; this is referred to as the "fifth structural unit").
• the "alcoholic hydroxyl group” refers to a group having a structure in which a hydroxyl group is directly bonded to an aliphatic hydrocarbon group.
• the aliphatic hydrocarbon group may be a chain hydrocarbon group or an alicyclic hydrocarbon group.
• the fifth structural unit is preferably a structural unit derived from an unsaturated monomer having an alcoholic hydroxyl group.
• the structure of the unsaturated monomer that gives the fifth structural unit is not particularly limited.
• Examples of the fifth structural unit include structural units represented by the following formula: (In the formula, R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)
• the content of the fifth structural unit is preferably 1 mol% or more, and more preferably 3 mol% or more, based on all structural units constituting the polymer [A].
• the content of the fifth structural unit is preferably 30 mol% or less, and more preferably 20 mol% or less, based on all structural units constituting the polymer [A].
• Other structural units include, in addition to those mentioned above, structural units containing a cyano group, a nitro group, or a sulfonamide group (specifically, a structural unit derived from 2-cyanomethyladamantan-2-yl (meth)acrylate, etc.), structural units containing a non-acid-dissociable hydrocarbon group (specifically, a structural unit derived from substituted or unsubstituted styrene (e.g., a styrene unit, a 4-iodostyrene unit, a 3-iodostyrene unit, etc.), a structural unit derived from vinylnaphthalene, a structural unit derived from n-pentyl (meth)acrylate, etc.).
• the content ratio of these structural units can be set appropriately according to each structural unit within a range that does not impair the effects of the present disclosure.
• the content of the polymer [A] is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 85% by mass or more, based on the total amount of solids contained in the composition.
• the content of the polymer [A] is preferably 99% by mass or less, more preferably 98% by mass or less, and even more preferably 95% by mass or less, based on the total amount of solids contained in the composition.
• the polymer [A] preferably constitutes the base resin of the present composition.
• base resin means a polymer component that accounts for 50% by mass or more of the total amount of solids contained in the composition.
• the present composition may contain only one type of polymer [A], or may contain two or more types.
• the weight average molecular weight (Mw) of the polymer [A] in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 1,000 or more, more preferably 2,000 or more, even more preferably 3,000 or more, and even more preferably 4,000 or more.
• Mw is preferably 50,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, and even more preferably 15,000 or less.
• the ratio (Mw/Mn) of Mw to the number average molecular weight (Mn) of the polymer [A] in terms of polystyrene measured by GPC is preferably 5.0 or less, more preferably 3.0 or less, even more preferably 2.0 or less, and even more preferably 1.8 or less. Furthermore, Mw/Mn is usually 1.0 or more, and preferably 1.2 or more.
• the polymer [A] can be synthesized, for example, by polymerizing monomers that provide each structural unit in an appropriate solvent using a known radical polymerization initiator, etc.
• [B] radiation-sensitive acid generator (hereinafter, also simply referred to as "[B] acid generator”) is a compound that generates an acid upon exposure to light.
• [B] acid generator is a salt consisting of a cation and a sulfonate anion, and the cation further has a fluorine atom, and the sulfonate anion has an aromatic ring (Ia) to which an iodine atom is bonded and an aromatic ring (IIa) to which an acidic functional group is bonded.
• the aromatic ring (Ia) does not have an acidic functional group bonded thereto, and the aromatic ring (IIa) does not have an iodine atom bonded thereto.
• the sulfonate anion constituting the [B] acid generator is an anion that has an aromatic ring (Ia) to which an iodine atom is bonded and an acidic functional group is not bonded thereto, and an aromatic ring (IIa) to which an acidic functional group is bonded and an iodine atom is not bonded thereto, and does not have an aromatic ring to which an iodine atom and an acidic functional group are bonded.
• the acid generator liberates a sulfonate anion by decomposing a cation (more specifically, a radiation-sensitive cation) under the action of radiation.
• This liberated sulfonate anion bonds with a hydrogen atom extracted from a component contained in the composition (e.g., the radiation-sensitive acid generator itself or a solvent), generating an acid derived from the sulfonate anion.
• radiation includes electron beams (visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), etc.) and electromagnetic waves (X-rays, gamma rays, etc.).
• [B] acid generator is preferably blended in the composition as a radiation-sensitive acid generator.
• the acid generated by [B] acid generator upon exposure is preferably a strong acid that induces dissociation of an acid-dissociable group under normal conditions.
• normal conditions here refers to conditions in which post-exposure baking (PEB) is performed at 110°C for 60 seconds.
• the composition preferably contains [B] acid generator as a radiation-sensitive acid generator together with [A] polymer, and generates acid groups by eliminating the acid-dissociable group with the acid derived from [B] acid generator generated upon exposure to radiation, thereby changing the solubility of [A] polymer in a developer.
• introducing an aromatic ring bonded to an iodine atom into a radiation-sensitive acid generator contributes to improving the sensitivity to exposure.
• the solubility of the radiation-sensitive acid generator in a developer tends to decrease. Therefore, the present inventors have considered further introducing a functional group (e.g., an acidic functional group) that contributes to improving the solubility in a developer into a radiation-sensitive acid generator into which an aromatic ring bonded to an iodine atom has been introduced.
• a functional group e.g., an acidic functional group
• the cation (hereinafter also referred to as "fluorine-containing cation”) contained in the acid generator (B) may have one or more fluorine atoms, and its structure is not particularly limited. From the viewpoint of sensitivity, the fluorine-containing cation preferably has at least one group (hereinafter also referred to as "group Rf 1 ”) selected from the group consisting of a fluoroalkyl group and a fluoro group (excluding the fluoro group in the fluoroalkyl group).
• group Rf 1 group selected from the group consisting of a fluoroalkyl group and a fluoro group (excluding the fluoro group in the fluoroalkyl group).
• the fluoroalkyl group may be linear or branched.
• the fluoroalkyl group preferably has 1 to 10 carbon atoms, and examples thereof include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,2-trifluoro-1-(trifluoromethyl)ethyl group, a perfluoro n-propyl group, a perfluoroisopropyl group, a perfluoro n-butyl group, a perfluoroisobutyl group, a perfluoro t-butyl group, a 2,2,3,3,4,4,5,5-octafluoropentyl group, and a perfluorohexyl group.
• the fluoroalkyl group possessed by the fluorine-containing cation preferably has 1 to 5 carbon atoms, and a trifluoromethyl group, a 2,2,2-trifluoroethyl group, or a perfluoroethyl group is more preferable, and a trifluoromethyl group is even more preferable.
• the group Rf1 is preferably a fluoro group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group or a perfluoroethyl group, and more preferably a fluorine atom or a trifluoromethyl group.
• the number of groups Rf1 in the fluorine-containing cation is preferably 2 or more, more preferably 3 or more, from the viewpoint of further improving the sensitivity and LWR performance of the present composition.
• the number of groups Rf1 in the fluorine-containing cation is preferably 10 or less, more preferably 8 or less, even more preferably 7 or less, and even more preferably 6 or less.
• the number of fluoroalkyl groups in the fluorine-containing cation is the number of groups Rf 1 that the fluorine-containing cation has. Therefore, for example, when the fluorine-containing cation has two trifluoromethyl groups (-CF 3 ), the number of groups Rf 1 that the fluorine atom cation has is two. In addition, when the fluorine-containing cation has one fluoro group (-F) and two trifluoromethyl groups (-CF 3 ) bonded to an aromatic ring, the number of groups Rf 1 that the fluorine-containing cation has is three.
• the bonding position of the group Rf 1 in the fluorine-containing cation is not particularly limited. In terms of the high effect of improving the sensitivity of the present composition, it is preferable that one or more of the groups Rf 1 are bonded to an aromatic ring contained in the fluorine-containing cation, and more preferably, two or more groups Rf 1 are bonded to an aromatic ring.
• the fluorine-containing cation has two or more groups Rf 1
• the two or more groups Rf 1 may be bonded to the same aromatic ring in the fluorine-containing cation or may be bonded to different aromatic rings.
• the fluorine-containing cation has one or more aromatic rings (hereinafter also referred to as "aromatic ring R A ”) that are bonded to a sulfonium cation or an iodonium cation, and it is preferable that the group Rf 1 is bonded to the aromatic ring R A.
• aromatic ring R A aromatic rings
• a certain group is "bonded to an aromatic ring” means that the certain group is directly bonded to the aromatic ring.
• the aromatic ring R A examples include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring.
• the aromatic ring R A is preferably a benzene ring or a naphthalene ring, and particularly preferably a benzene ring.
• the total number of groups Rf 1 bonded to the aromatic ring R A is preferably 2 or more, more preferably 3 or more.
• the total number of groups Rf 1 bonded to the aromatic ring R A is preferably 10 or less, more preferably 8 or less, even more preferably 7 or less, and even more preferably 6 or less.
• the groups Rf 1 may be bonded to the same aromatic ring in the fluorine-containing cation, or may be bonded to different aromatic rings.
• Preferred specific examples of the fluorine-containing cation include a cation in which one or more of R 1a , R 2a, and R 3a in the following formula (3) are the group Rf1 , a cation in which one or more of R 4a and R 5a in the following formula (4) are the group Rf1 , and a cation in which one or more of R 6a and R 7a in the following formula (5) are the group Rf1 .
• R 1a and R 2a are each independently a monovalent substituent, or R 1a and R 2a taken together represent a single bond or a divalent group connecting the rings to which they are bonded.
• R 3a is a monovalent substituent.
• a1 and a2 are each independently an integer of 0 to 5.
• a3 is an integer of 0 to (2 ⁇ r+5).
• r is 0 or 1.
• R 4a and R 5a are each independently a monovalent substituent, and a4 and a5 are each independently an integer of 0 to 5.
• a6 is an integer of 0 to 7.
• R 6a is a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, or a halogen atom.
• the multiple R 6a are the same or different and are a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, or a halogen atom, or two of the multiple R 6a are combined together to represent a ring structure having 4 to 20 ring members and the carbon atom to which they are bonded.
• a7 is an integer of 0 to 6. When a7 is 1, R 7a is a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, or a halogen atom.
• the multiple R 7a are the same or different and are a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, or a halogen atom, or two of the multiple R 7a are combined with each other to represent a ring structure having 3 to 20 ring members formed together with the carbon atom to which they are bonded.
• t1 is an integer of 0 to 3.
• R 8a is a single bond or a divalent organic group having 1 to 20 carbon atoms.
• t2 is 0 or 1.
• examples of the monovalent substituent represented by R 1a , R 2a , R 3a , R 4a and R 5a include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkyloxy group, an ester group, an alkylsulfonyl group, a cycloalkylsulfonyl group, a hydroxyl group, a carboxy group, a cyano group, a nitro group, and the like.
• the alkyl groups represented by R 1a to R 5a may be linear or branched.
• the alkyl groups preferably have 1 to 10 carbon atoms.
• the alkyl groups represented by R 1a to R 5a preferably have 1 to 5 carbon atoms, and are more preferably a methyl group, an ethyl group, an n-butyl group, or a t-butyl group.
• Specific examples of when R 1a to R 5a are alkoxy groups include groups having the alkyl groups exemplified above in the alkyl group moiety constituting the alkoxy group.
• the alkoxy group is preferably a methoxy group, an ethoxy group, an n-propoxy group, or an n-butoxy group.
• the cycloalkyl group represented by R 1a to R 5a may be either monocyclic or polycyclic.
• monocyclic cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups.
• polycyclic cycloalkyl groups include norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl groups.
• Specific examples of the cycloalkyloxy group represented by R 1a to R 5a include the cycloalkyl group exemplified above in the cycloalkyl group moiety constituting the cycloalkyloxy group.
• the cycloalkyloxy group represented by R 1a to R 5a is preferably a cyclopentyloxy group or a cyclohexyloxy group.
• R 1a to R 5a have a substituent
• substituents include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, and an alkoxy group having 1 to 5 carbon atoms.
• R 1a to R 5a are ester groups (-COOR)
• examples of the hydrocarbon portion (R) of the ester group include the above-mentioned substituted or unsubstituted alkyl groups or substituted or unsubstituted cycloalkyl groups.
• R 1a to R 5a are ester groups
• R 1a to R 5a are preferably a methoxycarbonyl group, an ethoxycarbonyl group, or an n-butoxycarbonyl group.
• examples of the alkyl group portion constituting the alkylsulfonium group include the above-mentioned substituted or unsubstituted alkyl groups.
• R 1a to R 5a are cycloalkylsulfonyl groups
• alkyl group portion constituting the cycloalkylsulfonium group include the above-mentioned substituted or unsubstituted cycloalkyl groups.
• R 1a and R 2a are taken together to represent a divalent group linking the rings to which they are bonded
• examples of the divalent group include -COO-, -OCO-, -CO-, -O-, -SO-, -SO 2 -, -S-, an alkanediyl group having 1 to 3 carbon atoms, an alkenediyl group having 2 or 3 carbon atoms, and a group having -O-, -S-, -COO-, -OCO-, -CO-, -SO-, or -SO 2 - between the carbon-carbon bonds of an ethylene group.
• R 1a and R 2a are a single bond linking the rings, or form -O- or -S-.
• a1 is preferably an integer of 0 to 2.
• one of R 1a in the above formula (3) is a fluorine atom or a trifluoromethyl group, and the remaining are each independently a fluorine atom, an iodine atom, or a trifluoromethyl group.
• a2 is preferably an integer of 0 to 2.
• one of R 2a in the above formula (3) is a fluorine atom or a trifluoromethyl group, and the remaining are each independently a fluorine atom, an iodine atom, or a trifluoromethyl group.
• a3 is preferably an integer of 0 to 2.
• R 3a in the above formula (3) is a fluorine atom or a trifluoromethyl group, and the remaining are each independently a fluorine atom, an iodine atom, or a trifluoromethyl group.
• all of a1, a2 and a3 are independently an integer of 0 to 2, and it is more preferable that all of a1, a2 and a3 are independently 1 or 2, and at least one R 1a , at least one R 2a and at least one R 3a in the above formula (3) are fluorine atoms, and the remaining are independently an iodine atom or a trifluoromethyl group.
• both R 1a are fluorine atoms, and it is particularly preferable that fluorine atoms are bonded to two meta positions relative to the bonding position of the sulfur atom.
• both R 2a are fluorine atoms, and it is particularly preferable that fluorine atoms are bonded to two meta positions relative to the bonding position of the sulfur atom.
• a4 is preferably an integer of 0 to 2.
• one of R 4a in the above formula (4) is a fluorine atom or a trifluoromethyl group, and the remaining are preferably each independently a fluorine atom, an iodine atom, or a trifluoromethyl group.
• a5 is preferably an integer of 0 to 2.
• one of R 5a in the above formula (4) is preferably a fluorine atom or a trifluoromethyl group, and the remaining are preferably each independently a fluorine atom, an iodine atom, or a trifluoromethyl group.
• both a4 and a5 are preferably each independently an integer of 0 to 2
• both a4 and a5 are preferably each independently 1 or 2
• at least one R 4a and at least one R 4a in the above formula (4) are each a fluorine atom, and the remaining are each independently an iodine atom or a trifluoromethyl group.
• examples of the monovalent organic group having 1 to 20 carbon atoms represented by R 6a and R 7a include substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, -OR k , -COOR k , -O-CO-R k , -O-R kk -COOR k , -R kk -CO-R k , -OSO 2 -R k or -SO 2 -R k .
• R k is a monovalent hydrocarbon group having 1 to 10 carbon atoms.
• R kk is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.
• Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include the same groups as those exemplified as the monovalent hydrocarbon groups represented by R 13 to R 15 in the above formula (ii-1).
• examples of the substituent substituting the hydrogen atom of the hydrocarbon group include the same groups as those exemplified as the substituents of the groups represented by R 1a to R 5a above.
• examples of the divalent organic group represented by R 8a include groups in which one hydrogen atom has been removed from the monovalent organic groups having 1 to 20 carbon atoms exemplified as R 6a and R 7a .
• R 6a and R 7a are preferably a linear or branched monovalent alkyl group, a monovalent fluoroalkyl group, a monovalent aromatic hydrocarbon group, -OSO 2 -R k , -SO 2 -R k or a halogen atom.
• a6 is preferably an integer of 0 to 2, and more preferably 0 or 1.
• a7 is preferably an integer of 0 to 2, and more preferably 0 or 1.
• t2 is preferably 0.
• t1 is preferably 2 or 3.
• the fluorine-containing cation preferably has a triarylsulfonium cation structure or a diaryliodonium cation structure.
• the cation is represented by the above formula (3) or the above formula (4), and it is even more preferable that the cation is represented by the above formula (3).
• fluorine-containing cation examples include cations represented by the following formulae, but are not limited to these.
• the sulfonate anion constituting the acid generator has an aromatic ring (Ia) to which an iodine atom is bonded and an aromatic ring (IIa) to which an acidic functional group is bonded.
• aromatic ring (Ia) to which an iodine atom is bonded and the aromatic ring (IIa) to which an acidic functional group is bonded include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring.
• the aromatic rings in the aromatic ring (Ia) and the aromatic ring (IIa) are preferably each independently a benzene ring or a naphthalene ring, and more preferably a benzene ring.
• the number of iodine atoms (iodine groups) bonded to the aromatic ring is preferably 2 or more, and more preferably 3 or more, from the viewpoint of improving the sensitivity of the composition. Furthermore, from the viewpoint of balancing the effect of improving sensitivity with the ease of synthesis of the acid generator [B], the number of iodine atoms bonded to the aromatic ring is preferably 5 or less, and more preferably 4 or less.
• the acidic functional group of the aromatic ring (IIa) is not particularly limited as long as it is a functional group capable of releasing a proton (H + ).
• the acidic functional group of the aromatic ring (IIa) is preferably at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a thiophenol group, and a sulfo group, in that it can further increase the solubility of the exposed portion in the developer, and more preferably at least one selected from the group consisting of a hydroxyl group, a carboxyl group, and a sulfo group.
• a hydroxyl group is particularly preferred in that it can further increase the sensitivity and LWR performance of the present composition.
• the number of acidic functional groups bonded to the aromatic ring is preferably 3 or less, more preferably 1 or 2, and even more preferably 1, in terms of improving the sensitivity of the present composition.
• the aromatic ring (Ia) and aromatic ring (IIa) may each further have a functional group other than the iodine atom and the acidic functional group as a substituent.
• substituents that the aromatic ring (Ia) or aromatic ring (IIa) may have include a fluorine atom, a chlorine atom, a bromine atom, an alkyl group, an alkoxy group, a cycloalkyloxy group, an ester group, an alkylsulfonyl group, a cycloalkylsulfonyl group, a cyano group, a nitro group, an acetyl group, and a fluoroacetyl group.
• the number of substituents other than the iodine atom and the acidic functional group is, for example, 5 or less, and preferably 2 or less.
• the number of aromatic rings (Ia) in the sulfonate anion is not particularly limited. From the viewpoint of achieving a balance between the effect of improving sensitivity and the ease of synthesis of the acid generator [B], the number of aromatic rings (Ia) in the sulfonate anion is, for example, 4 or less, and preferably 3 or less. Similarly, the number of aromatic rings (IIa) in the sulfonate anion is not particularly limited. From the viewpoint of achieving a balance between the effect of improving sensitivity and the ease of synthesis of the acid generator [B], the number of aromatic rings (IIa) in the sulfonate anion is, for example, 4 or less, preferably 2 or less, and more preferably 1.
• a preferred example of the acid generator (B) is an onium salt represented by the following formula (1).
• W 1 is a monovalent group represented by the following formula (2-1), formula (2-2) or formula (2-3).
• L 1 is a single bond or a divalent linking group. However, L 1 does not have an aromatic ring to which an acidic functional group and an iodine atom are bonded.
• R 1 , R 2 , R 3 and R 4 are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, a fluorine atom or a fluoroalkyl group having 1 to 10 carbon atoms.
• a is an integer of 0 to 8.
• a is 2 or more, a plurality of R 3s and R 4s are the same or different from each other.
• at least one of the (a ⁇ 2+2) groups constituting the group consisting of R 1 , R 2 , R 3 and R 4 in the formula is a fluorine atom or a fluoroalkyl group.
• X + is a monovalent cation having a fluorine atom.
• X1 and X2 are each independently a monovalent aromatic ring group having an iodine atom bonded to the aromatic ring and no acidic functional group bonded to the aromatic ring.
• X3 is a divalent aromatic ring group having an iodine atom bonded to the aromatic ring and no acidic functional group bonded to the aromatic ring.
• Y1 and Y3 are each independently a monovalent aromatic ring group having an acidic functional group bonded to the aromatic ring and no iodine atom bonded to the aromatic ring.
• Y2 is a divalent aromatic ring group having an acidic functional group bonded to the aromatic ring and no iodine atom bonded to the aromatic ring.
• A1a, A1b, A2a, and A3a are each independently a single bond or a divalent linking group.
• B1 is an organic group having 1 to 30 carbon atoms.
• A1a , A1b , A2a , A3a , and B1 are each independently a monovalent aromatic ring group having an acidic functional group bonded to the aromatic ring and no iodine atom bonded to the aromatic ring. 1 does not have an aromatic ring to which an acidic functional group and an iodine atom are bonded.
• n1, n2, n3, and n4 are each independently an integer from 1 to 4. When a plurality of X 1 , Y 1 , X 2 , and Y 3 are present, the plurality of X 1 , Y 1 , X 2 , and Y 3 are each the same or different. "*" represents a bond.)
• W 1 has two or more aromatic rings, and has a partial structure in which an iodine atom and an acidic functional group are bonded to different aromatic rings. However, W 1 does not have an aromatic ring to which an acidic functional group and an iodine atom are bonded.
• the type of aromatic ring possessed by the monovalent aromatic ring group represented by X 1 or X 2 and the divalent aromatic ring group represented by X 3 , the number of iodine atoms bonded to the aromatic ring, specific examples and preferred examples of other substituents that may be bonded to the aromatic ring are the same as the examples in the description of the aromatic ring (Ia) described above.
• examples of the divalent linking group represented by A 1a , A 1b , A 2a or A 3a include -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH-, -NHCO-, an alkanediyl group having 1 to 5 carbon atoms, an alkenediyl group having 2 to 5 carbon atoms, and a divalent group in which some methylene groups in an alkanediyl group having 2 to 5 carbon atoms or an alkenediyl group having 3 to 5 carbon atoms are replaced with -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH- or -NHCO-.
• a 1a , A 1b and A 3a are preferably a divalent linking group, and particularly preferably -O-, -CO-, -COO-, -OCO-, -S-, -SO 2 -, -CONH-, -NHCO-, an alkanediyl group having 1 to 5 carbon atoms, an alkenediyl group having 2 to 5 carbon atoms, or a divalent group in which some methylene groups in an alkanediyl group having 2 to 5 carbon atoms have been substituted with -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH- or -NHCO-.
• a 2a is preferably a divalent linking group, and particularly preferably -CO-, -COO-, -OCO-, -SO 2 -, -CONH-, -NHCO-, an alkanediyl group having 1 to 5 carbon atoms, an alkenediyl group having 2 to 5 carbon atoms, or a divalent group in which some methylene groups in an alkanediyl group having 2 to 5 carbon atoms have been substituted with -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH- or -NHCO-.
• the organic group having 1 to 30 carbon atoms represented by B1 may be constituted by a chain structure or may have a cyclic structure. Specific examples of the organic group having 1 to 30 carbon atoms represented by B1 include, for example, a substituted or unsubstituted chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic group having 3 to 30 carbon atoms, and an aromatic ring group having 6 to 30 carbon atoms.
• the organic group having 1 to 30 carbon atoms represented by B1 preferably has a cyclic structure, is more preferably an alicyclic group having 3 to 30 carbon atoms or an aromatic ring group having 6 to 30 carbon atoms, and is even more preferably an alicyclic group having 3 to 30 carbon atoms.
• the aliphatic ring of the alicyclic group may be an aliphatic hydrocarbon ring or an aliphatic heterocycle.
• the aliphatic hydrocarbon ring may be a monocyclic or polycyclic ring, and may be a saturated or unsaturated hydrocarbon ring. Examples of the saturated hydrocarbon ring among the monocyclic aliphatic hydrocarbon rings include a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, and a cyclooctane ring.
• Examples of the unsaturated hydrocarbon ring among the monocyclic aliphatic hydrocarbon rings include a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, a cyclooctene ring, and a cyclodecene ring.
• the polycyclic aliphatic hydrocarbon ring may be either a bridged alicyclic hydrocarbon structure or a condensed alicyclic hydrocarbon structure.
• the polycyclic aliphatic hydrocarbon ring is preferably a bridged alicyclic saturated hydrocarbon ring, and is preferably a bicyclo[2.2.1]heptane ring, a bicyclo[2.2.2]octane ring or a tricyclo[3.3.1.1 3,7 ]decane ring.
• Aliphatic heterocycles include rings having a cyclic ether structure, a cyclic acetal structure, a lactone structure, a cyclic carbonate structure, a sultone structure, or a thioxane structure.
• Aliphatic heterocycles may be either monocyclic or polycyclic, and may have either a bridged structure, a condensed ring structure, or a spiro ring structure.
• Aliphatic heterocycles may also be a combination of two or more of a bridged structure, a condensed ring structure, and a spiro ring structure.
• examples of the substituent include a fluorine atom, a chlorine atom, a bromine atom, an alkyl group, an alkoxy group, a cycloalkyloxy group, an ester group, an alkylsulfonyl group, a cycloalkylsulfonyl group, a cyano group, a nitro group, an acetyl group, and a fluoroacetyl group.
• the valence of the organic group having 1 to 30 carbon atoms represented by B 1 is determined according to the types of A 1a and A 1b . Specifically, when A 1a and A 1b are both divalent linking groups, the organic group having 1 to 30 carbon atoms represented by B 1 is trivalent. In addition, when A 1a is a single bond and A 1b is a divalent linking group, the organic group having 1 to 30 carbon atoms represented by B 1 is (n1+2) valent. When A 1a is a divalent linking group and A 1b is a single bond, the organic group having 1 to 30 carbon atoms represented by B 1 is (n2+2) valent.
• the organic group having 1 to 30 carbon atoms represented by B 1 is (n1+n2+1) valent.
• n1, n2, n3, and n4 is preferably 1 or 2, and more preferably 1, independently.
• examples of the divalent linking group represented by L1 include -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH-, -NHCO-, a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenediyl group having 2 to 10 carbon atoms, a divalent alicyclic group having 3 to 20 carbon atoms, and a divalent group in which some methylene groups in an alkanediyl group having 2 to 10 carbon atoms or an alkenediyl group having 3 to 10 carbon atoms are substituted with -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH- or -NHCO-.
• the divalent linking group represented by L1 is a divalent alicyclic group having 3 to 20 carbon atoms
• the aliphatic ring contained in the alicyclic group may be an aliphatic hydrocarbon ring or an aliphatic heterocycle.
• Specific and preferred examples of the divalent linking group represented by L1 which is a divalent alicyclic group having 3 to 20 carbon atoms include the same examples as those described for the organic group having 1 to 30 carbon atoms represented by B1 .
• L 1 is preferably a single bond, -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH-, -NHCO-, a substituted or unsubstituted alkanediyl group having 1 to 8 carbon atoms, or a divalent group in which some methylene groups in an alkanediyl group having 2 to 5 carbon atoms are substituted with -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH- or -NHCO-.
• L 1 is preferably -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH-, -NHCO-, a substituted or unsubstituted alkanediyl group having 1 to 8 carbon atoms, a divalent alicyclic group having 3 to 10 carbon atoms, or a divalent group in which some methylene groups in an alkanediyl group having 2 to 5 carbon atoms are replaced by -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO 2 -, -CONH- or -NHCO-.
• Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R 1 , R 2 , R 3 or R 4 include a monovalent linear hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 10 carbon atoms. Specific examples of these include the same groups having the same carbon number as the groups exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 13 to R 15 , R 17 to R 19 or R 32 to R 34 in the above formulas (ii-1) to (ii-3).
• the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R 1 , R 2 , R 3 or R 4 is preferably a monovalent linear hydrocarbon group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms.
• Examples of the fluoroalkyl group represented by R 1 , R 2 , R 3 or R 4 include 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-diethylpentyl group.
• R1 and R2 are a fluorine atom or a trifluoromethyl group, and it is more preferable that R1 is a fluorine atom or a trifluoromethyl group and R2 is a fluorine atom or a trifluoromethyl group.
• R3 and R4 are preferably each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, in that this can improve the sensitivity of the present composition.
• a is preferably an integer of 0 to 5, and more preferably an integer of 0 to 2.
• acid generator [B] examples include compounds represented by the following formulas (1-1) to (1-15), but the acid generator [B] is not limited to the compounds represented by the following structural formulas.
• X + represents a monovalent cation having a fluorine atom. Specific examples and preferred examples of X + are as described above.
• the compounds represented by the above formulas (1-1) to (1-15) are compounds in which W 1 in the above formula (1) is a group represented by the above formula (2-1).
• the compounds represented by the above formulas (1-5) to (1-9) are compounds in which W 1 in the above formula (1) is a group represented by the above formula (2-2), and the compounds represented by the above formulas (1-10), (1-11), (1-14) and (1-15) are compounds in which W 1 in the above formula (1) is a group represented by the above formula (2-3).
• the content of the acid generator [B] is preferably 2 parts by mass or more, and more preferably 5 parts by mass or more, per 100 parts by mass of the polymer [A].
• the content of the acid generator [B] is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, per 100 parts by mass of the polymer [A].
• the acid generator [B] one type can be used alone, or two or more types can be used in combination.
• the acid generator [B] can be synthesized by appropriately combining standard methods in organic chemistry, as shown in the examples described later.
• a compound in which W 1 in the above formula (1) is a group represented by the above formula (2-1) can be obtained by, for example, a method of generating the compound by utilizing a cyclic acetalization reaction between a carbonyl compound having an aromatic ring (Ia) and an aromatic ring (IIa) and an onium salt consisting of a sulfonate anion having two hydroxyl groups and a fluorine-containing cation.
• a compound in which W 1 in the above formula (1) is a group represented by the above formula (2-2) can be obtained by, for example, a method of reacting (condensing) a carboxylic acid having a partial structure represented by the above formula (2-2) with an onium salt consisting of a sulfonate anion having a hydroxyl group and a fluorine-containing cation.
• a compound in which W 1 in the above formula (1) is a group represented by the above formula (2-3) can be obtained, for example, by a method in which a hydroxyl-containing compound having a partial structure represented by the above formula (2-3) is reacted (condensed) with an onium salt consisting of a sulfonate anion having a carboxyl group and a fluorine-containing cation, etc.
• the method for synthesizing the acid generator [B] is not limited to the above.
• the other acid generator [C] may be a radiation-sensitive acid generator or an acid diffusion controller.
• the present composition preferably contains the other acid generator [C] as an acid diffusion controller.
• the acid diffusion controller blended in the present composition as the other acid generator [C] is also referred to as "acid diffusion controller [C A ]."
• the acid diffusion controller is a component that can suppress chemical reactions caused by acid in unexposed areas by suppressing the diffusion of acid generated in the resist film upon exposure of the composition within the resist film.
• the lithography properties (LWR performance and CDU performance) of the composition can be further improved.
• the acid diffusion controller [CA] As the acid diffusion controller [CA], a compound (photodegradable base) that generates an acid having a weaker acidity than the acid generated by the acid generator [B] is preferably used.
• the acidity can be evaluated by the acid dissociation constant (pKa).
• the acid dissociation constant of the acid generated by the acid diffusion controller [CA] is usually -3 or more, preferably -1 ⁇ pKa ⁇ 7, and more preferably 0 ⁇ pKa ⁇ 5.
• the acid generated by the acid diffusion controller [CA] is typically a weak acid that does not induce dissociation of an acid dissociable group under the above-mentioned normal conditions.
• the [CA] acid diffusion control agent an onium salt consisting of a cation (more specifically, a radiation-sensitive onium cation) and an organic anion can be preferably used.
• the [CA] acid diffusion control agent is preferably an onium salt that generates a carboxylic acid, a sulfonic acid, or a sulfonamide upon exposure.
• an onium salt having a sulfonium cation structure or an iodonium cation structure can be preferably used as the [CA] acid diffusion control agent.
• the [CA] acid diffusion control agent one type may be used alone, or two or more types may be used in combination.
• the acid diffusion controller [CA] include the following compound (c1) and compound (c2).
• Compound (c1) an onium salt consisting of an organic anion having an iodine atom and a cation.
• Compound (c2) an onium salt consisting of a cation having a fluorine atom and an organic anion.
• the organic anion of the compound (c1) has only to have one or more iodine atoms, and its structure is not particularly limited.
• the organic anion of the compound (c1) (hereinafter also referred to as "iodine-containing anion (ca)") can be exemplified by sulfonate anion structure, imide anion structure, methyl anion structure, carboxylate anion structure, etc.
• the iodine-containing anion (ca) preferably has a sulfonate anion structure or a carboxylate anion structure, and more preferably has a carboxylate anion structure.
• the number of iodine atoms contained in the iodine-containing anion (ca) is preferably 2 or more. Furthermore, from the viewpoint of achieving a balance between increasing the sensitivity of the present composition and the ease of synthesis of compound (c1), the number of iodine atoms contained in the iodine-containing anion (ca) is preferably 10 or less, and more preferably 8 or less.
• the bonding position of the iodine atom in the iodine-containing anion (ca) is not particularly limited. In terms of the high effect of improving the sensitivity of the present composition, it is preferable that the iodine-containing anion (ca) has an aromatic ring and has a structure in which an iodine atom is bonded to the aromatic ring, and it is more preferable that two or more iodine atoms are bonded to the aromatic ring.
• the two or more iodine atoms may be bonded to the same aromatic ring in the iodine-containing anion (ca) or may be bonded to different aromatic rings.
• the aromatic ring to which the iodine atom is bonded is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.
• iodine-containing anion (ca) examples include organic anions represented by the following formulas: However, the iodine-containing anion (ca) is not limited to the following structures.
• the cation contained in the compound (c1) preferably has a sulfonium cation structure or an iodonium cation structure, and more preferably has a triarylsulfonium cation structure or a diaryliodonium cation structure.
• Specific examples of the cation contained in the compound (c1) include the fluorine-containing cations exemplified as the cation (X + ) contained in the acid generator (B) and the cations represented by the following formulas.
• the cation contained in the compound (c1) is not limited to these structures.
• compound (c1) include onium salts formed by any combination of the iodine-containing anions (ca) and cations exemplified above.
• the cation of the compound (c2) may have one or more fluorine atoms, and the structure is not particularly limited. From the viewpoint of sensitivity, the cation of the compound (c2) preferably has at least one group (group Rf 1 ) selected from the group consisting of a fluoroalkyl group and a fluoro group (excluding the fluoro group in the fluoroalkyl group). Specific and preferred examples of the cation of the compound (c2) include the same examples as the fluorine-containing cation described as the fluorine-containing cation of the acid generator [B].
• the organic anion contained in compound (c2) may, for example, be an anion having a sulfonate anion structure, an imide anion structure, a methyl anion structure, or a carboxylate anion structure.
• the organic anion contained in compound (c2) preferably has a sulfonate anion structure or a carboxylate anion structure, and more preferably has a carboxylate anion structure.
• the organic anion contained in compound (c2) may have an iodine atom.
• organic anion contained in the compound (c2) examples include an organic anion represented by the following formula and an anion exemplified as the iodine-containing anion (ca) contained in the compound (c1).
• organic anion contained in the compound (c2) is not limited to these structures.
• compound (c2) include onium salts formed by any combination of the fluorine-containing cations and organic anions exemplified above.
• a photodegradable base different from compound (c1) and compound (c2) may be used as the acid diffusion controller [CA].
• other photodegradable bases include onium salts consisting of a cation having no fluorine atom among those exemplified as the cations constituting compound (c1) and compound (c2) and an anion having no iodine atom among those exemplified as the anions constituting compound (c1) and compound (c2); salts having a cationic structure and an anionic structure in the same molecule (for example, intramolecular salts represented by each of the following formulas (c3-1) to (c3-3)), and the like.
• the acid diffusion control agent [CA] to be blended in this composition is preferably at least one selected from the group consisting of compound (c1) and compound (c2), since it can improve sensitivity and LWR performance in a well-balanced manner.
• the content of the acid diffusion control agent in the composition is preferably 1 molar part or more, more preferably 2 molar parts or more, and even more preferably 5 molar parts or more, based on 100 molar parts of the total amount of the acid generator [B] contained in the composition.
• the content of the acid diffusion control agent [CA] is preferably 150 molar parts or less, more preferably 140 molar parts or less, and even more preferably 135 molar parts or less, based on 100 molar parts of the total amount of the acid generator [B] contained in the composition.
• the composition may further contain a radiation-sensitive acid generator different from the acid generator [B] as another acid generator [C].
• a radiation-sensitive acid generator any known acid generator that is generally used in the formation of a resist film may be used as appropriate.
• the solvent [D] is not particularly limited as long as it can dissolve or disperse the components to be blended in the composition.
• an organic solvent can be preferably used.
• Specific examples of the solvent [D] include alcohols, ethers, ketones, amides, esters, and hydrocarbons.
• alcohols examples include aliphatic monoalcohols having 1 to 18 carbon atoms, such as 4-methyl-2-pentanol and n-hexanol; alicyclic monoalcohols having 3 to 18 carbon atoms, such as cyclohexanol; polyhydric alcohols having 2 to 18 carbon atoms, such as 1,2-propylene glycol; and partial ethers of polyhydric alcohols having 3 to 19 carbon atoms, such as propylene glycol monomethyl ether.
• ethers examples include dialkyl ethers, such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether, and diheptyl ether; cyclic ethers, such as tetrahydrofuran and tetrahydropyran; and aromatic ring-containing ethers, such as diphenyl ether and anisole.
• dialkyl ethers such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether, and diheptyl ether
• cyclic ethers such as tetrahydrofuran and tetrahydropyran
• aromatic ring-containing ethers such as diphenyl ether and anisole.
• Ketones include chain ketones such as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl iso-butyl ketone, 2-heptanone, ethyl n-butyl ketone, methyl n-hexyl ketone, di-iso-butyl ketone, and trimethylnonanone; cyclic ketones such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and methylcyclohexanone; 2,4-pentanedione, acetonylacetone, acetophenone, and diacetone alcohol.
• chain ketones such as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ket
• Amides include cyclic amides such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone; and chain amides such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.
• Esters include monocarboxylic acid esters such as n-butyl acetate, ethyl lactate, and methyl 2-hydroxyisobutyrate; polyhydric alcohol carboxylates such as propylene glycol diacetate; polyhydric alcohol partial ether carboxylates such as propylene glycol monomethyl ether acetate; polycarboxylic acid diesters such as diethyl oxalate; carbonates such as dimethyl carbonate and diethyl carbonate; and cyclic esters such as gamma-butyrolactone.
• Hydrocarbons include aliphatic hydrocarbons with 5 to 12 carbon atoms such as n-pentane and n-hexane; and aromatic hydrocarbons with 6 to 16 carbon atoms such as toluene and xylene.
• the solvent [D] it is preferable to use at least one selected from the group consisting of esters and ketones.
• the solvent [D] one or more types can be used.
• the high fluorine content polymer [F] (hereinafter also referred to as “polymer [F]”) is a polymer having a higher mass content of fluorine atoms than polymer [A]. Polymer [F] is contained in the present composition, for example, as a water repellent additive.
• the fluorine atom content of the polymer [F] is not particularly limited as long as it is larger than that of the polymer [A].
• the fluorine atom content of the polymer [F] is preferably 1% by mass or more, more preferably 4% by mass or more, and particularly preferably 7% by mass or more.
• the fluorine atom content of the polymer [F] is preferably 60% by mass or less, more preferably 40% by mass or less.
• the fluorine atom content (mass%) of the polymer can be calculated from the structure of the polymer determined by 13C -NMR spectrum measurement or the like.
• the content of the [F] polymer in the composition is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the [A] polymer.
• the content of the [F] polymer is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of the [A] polymer.
• the composition may contain only one type of [F] polymer, or may contain two or more types.
• the present composition may further contain a component (hereinafter, also referred to as "other optional components") different from the above-mentioned [A] polymer, [B] acid generator, [C] other acid generator, [D] solvent, and [F] high fluorine content polymer.
• a component hereinafter, also referred to as "other optional components”
• Examples of the other optional components include nitrogen-containing compounds (e.g., alkylamines, aromatic amines, polyamines, nitrogen-containing heterocyclic compounds (N-(undecane-1-ylcarbonyloxyethyl)morpholine, etc.), nitrogen-containing compounds having an acid dissociable group (N-(t-butoxycarbonyl)di-n-octylamine, N-t-butoxycarbonyl-4-hydroxypiperidine, etc.)), surfactants, alicyclic skeleton-containing compounds (e.g., 1-adamantanecarboxylic acid, 2-adamantanone, t-butyl deoxycholate, etc.), sensitizers, uneven distribution promoters, nitrogen-containing compounds, etc.
• the content of the other optional components in the present composition can be appropriately selected according to each component within a range that does not impair the effects of the present disclosure.
• the composition can be produced, for example, by mixing the polymer [A] and the acid generator [B], as well as the solvent [D], etc., in a desired ratio, and filtering the resulting mixture, preferably using a filter (e.g., a filter with a pore size of about 0.2 ⁇ m).
• the solid content concentration of the composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more.
• the solid content concentration of the composition is preferably 50% by mass or less, more preferably 20% by mass or less, and even more preferably 5% by mass or less.
• composition thus obtained can be used as a positive pattern-forming composition in which a pattern is formed using an alkaline developer, or as a negative pattern-forming composition in which a developer containing an organic solvent is used.
• the method for forming a resist pattern in the present disclosure includes a step of applying the present composition to one side of a substrate (hereinafter also referred to as a "coating step"), a step of exposing the resist film obtained by the coating step (hereinafter also referred to as an "exposure step”), and a step of developing the resist film exposed by the exposure step (hereinafter also referred to as a "development step”).
• Examples of patterns formed by the method for forming a resist pattern in the present disclosure include a line and space pattern and a hole pattern. Since the resist film is formed using the present composition in the method for forming a resist pattern in the present disclosure, the method for forming a resist pattern can form a resist pattern having good sensitivity, good lithography properties, and few development defects. Each step will be described below.
• the composition is applied to one side of a substrate to form a resist film on the substrate.
• substrates can be used for forming the resist film, 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 may be formed on the substrate and used.
• the coating method of the composition include rotary coating (spin coating), casting coating, and roll coating.
• soft baking SB, also called pre-baking
• the SB temperature is preferably 60° C. or higher, more preferably 80° C. or higher.
• the SB temperature is preferably 140° C.
• the SB time is preferably 5 seconds or higher, more preferably 10 seconds or higher.
• the SB time is preferably 600 seconds or lower, more preferably 300 seconds or lower.
• the average thickness of the resist film formed is preferably from 10 to 1,000 nm, and more preferably from 20 to 500 nm.
• the resist film obtained by the coating step is exposed.
• This exposure is performed by irradiating the resist film with radiation through a photomask, or in some cases through an immersion medium such as water.
• radiation include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and gamma rays; charged particle beams such as electron beams and alpha rays; and the like, depending on the line width of the target pattern.
• the radiation irradiated to the resist film formed using the present composition is preferably far ultraviolet light, EUV, or electron beams, more preferably ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV, or electron beams, even more preferably ArF excimer laser light, EUV, or electron beams, even more preferably EUV or electron beams, and particularly preferably EUV.
• PEB post-exposure bake
• the PEB temperature is preferably 50°C or higher, and more preferably 80°C or higher.
• the PEB temperature is preferably 180°C or lower, and more preferably 130°C or lower.
• the PEB time is preferably 5 seconds or longer, and more preferably 10 seconds or longer.
• the PEB time is preferably 600 seconds or shorter, and more preferably 300 seconds or shorter.
• the exposed resist film is developed. This allows a desired resist pattern to be formed.
• the resist film is generally washed with a rinse liquid such as water or alcohol, and then dried.
• the development method in the development step may be alkaline development or organic solvent development.
• examples of the developer used for development include an alkaline aqueous solution in which at least one of the following alkaline compounds is dissolved: 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, 1,5-diazabicyclo-[4.3.0]-5-nonene, etc.
• TMAH tetramethylammonium hydroxide
• the developer may be one or more of organic solvents such as hydrocarbons, ethers, esters, ketones, and alcohols, or solvents containing the above organic solvents.
• organic solvents used as the developer include the solvents listed as [D] in the description of this composition.
• esters and ketones are preferred.
• esters acetate esters are preferred, and n-butyl acetate is more preferred.
• ketones chain ketones are preferred, and 2-heptanone is more preferred.
• the content of the organic solvent is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more.
• components other than the organic solvent in the developer include water, silicone oil, etc.
• 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 while scanning a developer dispense nozzle at a constant speed onto 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 while scanning a developer dispense nozzle at a constant speed onto a substrate rotating at
• Weight average molecular weight (Mw) and number average molecular weight (Mn) of polymer The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were measured by gel permeation chromatography (GPC) using Tosoh GPC columns (G2000HXL: 2 columns, G3000HXL: 1 column, G4000HXL: 1 column) under the following analytical conditions: flow rate: 1.0 mL/min, elution solvent: tetrahydrofuran, sample concentration: 1.0 mass%, sample injection amount: 100 ⁇ L, column temperature: 40° C., detector: differential refractometer, using monodisperse polystyrene as a standard. The dispersity (Mw/Mn) was calculated from the measurement results of Mw and Mn.
• the polymerization solution was cooled to room temperature.
• the cooled polymerization solution was poured into hexane (500 parts by mass relative to 100 parts by mass of the polymerization solution), and the precipitated white powder was filtered off.
• the filtered white powder was washed twice with 100 parts by mass of hexane relative to 100 parts by mass of the polymerization solution, and then dissolved in 1-methoxy-2-propanol (300 parts by mass (based on 100 parts by mass of the polymerization solution, the same applies below)).
• methanol 500 parts by mass
• triethylamine 50 parts by mass
• ultrapure water 10 parts by mass
• the polymerization solution was cooled to room temperature.
• the cooled polymerization solution was poured into hexane (500 parts by mass relative to 100 parts by mass of the polymerization solution), and the precipitated white powder was filtered off.
• the filtered white powder was washed twice with 100 parts by mass of hexane relative to the polymerization solution, and then dried at 50° C. for 12 hours to obtain a white powdery polymer (A-13).
• Synthesis Examples 2-3 and 2-4 The same operations as in Synthesis Example 2-1 were carried out except that appropriately selected substrates were used instead of compound (P-1) and compound (K-1), to synthesize radiation-sensitive acid generators represented by the following formula (B-3) or formula (B-4).
• the resist film was subjected to PEB (post-exposure bake) at 110°C for 60 seconds.
• PEB post-exposure bake
• the resist was then developed with a 2.38% by weight aqueous solution of TMAH at 23° C. for 30 seconds to form a positive 32 nm line and space pattern.
• the resist film was subjected to PEB at 110°C for 60 seconds. Then, the wafer was developed at 23°C for 30 seconds using a 2.38% by mass aqueous TMAH solution to form a positive 150-nm line and space pattern.
• LWR performance The resist pattern formed by EUV exposure was observed from above using a scanning electron microscope. The line width was measured at 50 arbitrary points, and the 3 sigma value was calculated from the distribution of the measured values, which was defined as the LWR (unit: nm). The smaller the LWR value, the smaller the line wobble and the better the LWR performance. The LWR performance was evaluated as "A” when the LWR was 4.0 nm or less, "B” when it was more than 4.0 nm and less than 4.2 nm, and "C” when it was more than 4.2 nm.
• the radiation-sensitive composition was divided into two, one radiation-sensitive composition was stored at -15°C for 2 weeks, and the other radiation-sensitive composition was stored at 35°C for 2 weeks. Thereafter, a resist pattern was formed by KrF exposure using the radiation-sensitive composition stored at -15°C for 2 weeks and the radiation-sensitive composition stored at 35°C for 2 weeks, and the optimum exposure amount (sensitivity) for forming a 150 nm line and space pattern was determined.
• the radiation-sensitive compositions of Examples 1 to 25 all had good sensitivity and LWR performance while ensuring storage stability, in comparison with the radiation-sensitive compositions of Comparative Examples 1 to 4.
• the radiation-sensitive composition and resist pattern forming method disclosed herein can improve sensitivity and LWR performance while ensuring storage stability. Therefore, the radiation-sensitive composition and resist pattern forming method disclosed herein can be suitably used for forming fine resist patterns in the lithography process of various electronic devices such as semiconductor devices and liquid crystal devices.

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• 2024
  • 2024-03-13 JP JP2025510449A patent/JPWO2024203352A1/ja active Pending
  • 2024-03-13 KR KR1020257030010A patent/KR20250166893A/ko active Pending
  • 2024-03-13 WO PCT/JP2024/009865 patent/WO2024203352A1/ja not_active Ceased
  • 2024-03-18 TW TW113109900A patent/TW202449512A/zh unknown

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