Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/09—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers
  • G03F7/11—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers having cover layers or intermediate layers, e.g. subbing layers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/20—Exposure; Apparatus therefor
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/30—Imagewise removal using liquid means
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/30—Imagewise removal using liquid means
  • G03F7/32—Liquid compositions therefor, e.g. developers

Definitions

• the present invention relates to a method for manufacturing a semiconductor substrate and a composition for forming a resist underlayer film.
• a multilayer resist process is used in which a resist pattern is formed by exposing and developing a resist film laminated on a substrate via a resist underlayer film such as an organic underlayer film or a silicon-containing film. It is In this process, the resist underlayer film is etched using this resist pattern as a mask, and the substrate is further etched using the obtained resist underlayer film pattern as a mask, thereby forming a desired pattern on the semiconductor substrate.
• a resist underlayer film such as an organic underlayer film or a silicon-containing film.
• the resist underlayer film has a solvent resistance to the solvent of the resist composition and a resist film bottom.
• pattern rectangularity ensures the rectangularity of the resist pattern by suppressing the skirting of the pattern at the edge.
• the present invention has been made based on the above circumstances, and its object is to manufacture a semiconductor substrate using a composition for forming a resist underlayer film capable of forming a resist underlayer film having excellent solvent resistance and pattern rectangularity.
• An object of the present invention is to provide a method and a composition for forming a resist underlayer film.
• the present invention in one embodiment, a step of directly or indirectly applying a composition for forming a resist underlayer film onto a substrate; a step of applying a composition for forming a resist film to the resist underlayer film formed by the step of applying the composition for forming a resist underlayer film; a step of exposing the resist film formed by the step of applying the composition for forming a resist film to radiation; and developing at least the exposed resist film,
• the composition for forming a resist underlayer film is a polymer having a repeating unit containing a sulfonic acid group (hereinafter also referred to as "[A] polymer”);
• the present invention relates to a method for manufacturing a semiconductor substrate containing a solvent (hereinafter also referred to as "[C] solvent").
• the present invention in another embodiment, a polymer containing sulfonic acid groups;
• the present invention relates to a composition for forming a resist underlayer film containing a solvent and
• a semiconductor substrate can be efficiently manufactured because a composition for forming a resist underlayer film capable of forming a resist underlayer film having excellent solvent resistance and pattern rectangularity is used.
• a film having excellent solvent resistance and pattern rectangularity can be formed.
• the resist underlayer film can be removed together with the resist film in the development process in the manufacturing process of semiconductor substrates and the like, so that a film having excellent removability can be formed. can. Therefore, these can be suitably used for the manufacture of semiconductor devices, which are expected to be further miniaturized in the future.
• the method for producing a semiconductor substrate includes a step of directly or indirectly coating a substrate with a composition for forming a resist underlayer film (hereinafter also referred to as “coating step (I)”), and the composition for forming a resist underlayer film.
• a step of applying a resist film-forming composition to the resist underlayer film formed by the product coating step (hereinafter also referred to as “coating step (II)”), and the resist film-forming composition coating step A step of exposing the resist film formed by using radiation (hereinafter also referred to as an “exposure step”) and a step of developing at least the exposed resist film (hereinafter also referred to as a “developing step”). .
• a resist underlayer film having excellent solvent resistance and pattern rectangularity can be formed by using a predetermined composition for forming a resist underlayer film in the coating step (I). Therefore, a semiconductor substrate having a favorable pattern shape can be manufactured.
• the method for manufacturing a semiconductor substrate may optionally include a step of directly or indirectly forming a silicon-containing film on the substrate prior to the coating step (I) (hereinafter also referred to as a “silicon-containing film forming step”. ) may be further provided.
• composition for forming a resist underlayer film used in the method for manufacturing the semiconductor substrate and each step in the case where the step of forming the silicon-containing film, which is an optional step, is provided will be described.
• composition for forming a resist underlayer film contains [A] polymer and [C] solvent.
• the composition may contain optional ingredients as long as the effects of the present invention are not impaired.
• the composition for forming a resist underlayer film can form a resist underlayer film excellent in solvent resistance and pattern rectangularity.
• the reason is not clear, it is presumed as follows. Since a polymer containing a sulfonic acid group (that is, the [A] polymer) is used as the main component of the composition for forming a resist underlayer film, the polarity of the resist underlayer film is increased and the solubility in organic solvents is reduced. can be done.
• the acid generated from the sulfonic acid group in the resist underlayer film suppresses the acid deficiency at the bottom of the resist film in the exposed area, thereby increasing the solubility in the developer at the bottom of the resist film and exhibiting the pattern rectangularity. can.
• the polymer contains a sulfonic acid group.
• the composition may contain one or more [A] polymers.
• the polymer [A] as long as it contains a sulfonic acid group, a known polymer used for forming a resist underlayer film can be suitably employed. Among them, acrylic polymers are preferable from the viewpoints of ease of introduction of sulfonic acid groups, adhesion to resist films, and the like.
• the polymer when it is an acrylic polymer, it preferably has a repeating unit represented by the following formula (1) (hereinafter also referred to as “repeating unit (1)”).
• R 1 is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
• L 1 is a single bond or a divalent linking group.
• Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 1 include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. Examples include a hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a combination thereof.
• hydrocarbon group includes chain hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups. This "hydrocarbon group” includes a saturated hydrocarbon group and an unsaturated hydrocarbon group.
• a “chain hydrocarbon group” means a hydrocarbon group composed only of a chain structure without a ring structure, and includes both a straight chain hydrocarbon group and a branched chain hydrocarbon group.
• alicyclic hydrocarbon group means a hydrocarbon group that contains only an alicyclic structure as a ring structure and does not contain an aromatic ring structure, and includes monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic (However, it does not have to consist only of an alicyclic structure, and a part of it may contain a chain structure.).
• Aromatic hydrocarbon group means a hydrocarbon group containing an aromatic ring structure as a ring structure (however, it need not consist only of an aromatic ring structure; structure).
• Examples of monovalent chain hydrocarbon groups having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group and tert-butyl group.
• Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include cycloalkyl groups such as cyclopentyl group and cyclohexyl group; cycloalkenyl groups such as cyclopropenyl group, cyclopentenyl group and cyclohexenyl group; norbornyl group; bridging ring saturated hydrocarbon groups such as adamantyl group and tricyclodecyl group; and bridging ring unsaturated hydrocarbon groups such as norbornenyl group and tricyclodecenyl group.
• Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include phenyl group, tolyl group, naphthyl group, anthracenyl group and pyrenyl group.
• R 1 has a substituent
• substituents include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, a methoxy group, an ethoxy alkoxy groups such as propoxy groups, alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups, alkoxycarbonyloxy groups such as methoxycarbonyloxy groups and ethoxycarbonyloxy groups, formyl groups, acetyl groups, propionyl groups, butyryl groups, etc. an acyl group, a cyano group, a nitro group, and the like.
• R 1 is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerizability of the monomer that gives the repeating unit (1).
• the divalent linking group represented by L 1 is a divalent hydrocarbon group, a carbonyl group, an oxygen atom (-O-), an imino group (-NH-) or a combination thereof.
• L 1 is a divalent hydrocarbon group, a carbonyl group, an oxygen atom (-O-), an imino group (-NH-) or a combination thereof.
• -O- oxygen atom
• -NH- imino group
• Examples of the divalent hydrocarbon group for L 1 include groups obtained by removing one hydrogen atom from the above monovalent hydrocarbon group having 1 to 20 carbon atoms for R 1 .
• L 1 is a single bond, an alkanediyl group obtained by removing one hydrogen atom from an alkyl group having 1 to 10 carbon atoms, or one hydrogen atom from a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.
• An arylene group, a carbonyl group, an oxygen atom, an imino group, or a combination thereof excluding atoms is preferable, and a single bond, an alkanediyl group having 1 to 5 carbon atoms, a phenylene group, a carbonyl group, an oxygen atom, an imino group, or a combination thereof is more preferred.
• repeating unit (1) include repeating units represented by the following formulas (1-1) to (1-10).
• R 1 has the same definition as in formula (1) above. Among them, repeating units represented by the above formulas (1-1), (1-5) and (1-9) are preferable.
• the lower limit of the content of repeating units containing a sulfonic acid group in all repeating units constituting the polymer is preferably 1 mol%, more preferably 5 mol%, further preferably 10 mol%, and 20 mol%. Especially preferred.
• the upper limit of the content is preferably 100 mol%, more preferably 70 mol%, still more preferably 40 mol%, and particularly preferably 30 mol%.
• the polymer preferably further has a repeating unit represented by the following formula (2) (hereinafter also referred to as “repeating unit (2)”).
• repeating unit (2) By including the repeating unit (2) in the polymer, solvent resistance and pattern rectangularity can be further improved.
• R 2 is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
• L 2 is a single bond or a divalent linking group.
• the substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 2 includes the substituted or unsubstituted C 1 to R 1 of the above formula (1).
• a group shown as a monovalent hydrocarbon group having 1 to 20 carbon atoms can be preferably employed.
• R 2 is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerizability of the monomer that gives the repeating unit (2).
• R 2 has a substituent
• preferred examples of the substituent include the substituents that R 1 of the above formula (1) may have.
• L2 is a single bond, an alkanediyl group obtained by removing one hydrogen atom from an alkyl group having 1 to 10 carbon atoms, or a cycloalkylene group obtained by removing one hydrogen atom from a cycloalkyl group having 5 to 10 carbon atoms.
• an arylene group obtained by removing one hydrogen atom from a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a carbonyl group, an oxygen atom, or a combination thereof, a single bond, and an alkanediyl having 1 to 5 carbon atoms.
• a group, a cycloalkylene group having 5 to 7 carbon atoms, a phenylene group, a carbonyl group, an oxygen atom, or a combination thereof is more preferred.
• repeating unit (2) include repeating units represented by the following formulas (2-1) to (2-8).
• R 2 has the same definition as in formula (2) above.
• the lower limit of the content of the repeating unit (2) in the total repeating units constituting the [A] polymer is preferably 1 mol%, and 3 mol%. More preferably, 5 mol % is even more preferable.
• the upper limit of the content is preferably 99 mol%, more preferably 90 mol%, and even more preferably 80 mol%.
• the polymer further has a repeating unit represented by the following formula (3) (excluding the case of the above formula (2)) (hereinafter also referred to as “repeating unit (3)”).
• R 3 is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
• L 3 is a single bond or a divalent linking group.
• R 4 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
• the substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms represented by R 3 and R 4 are respectively substituted groups represented by R 1 in the above formula (1).
• a group shown as an unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms can be preferably employed.
• R 3 is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerizability of the monomer that gives the repeating unit (3).
• R 4 is preferably a monovalent chain hydrocarbon group having 1 to 15 carbon atoms, more preferably a monovalent branched chain alkyl group having 1 to 10 carbon atoms.
• preferred examples of the substituent include the substituents that R 1 in the above formula (1) can have.
• L3 is a single bond, an alkanediyl group obtained by removing one hydrogen atom from an alkyl group having 1 to 10 carbon atoms, or a cycloalkylene group obtained by removing one hydrogen atom from a cycloalkyl group having 5 to 10 carbon atoms.
• a carbonyl group, an oxygen atom or a combination thereof are preferred, a single bond, an alkanediyl group having 1 to 5 carbon atoms, a cycloalkylene group having 5 to 7 carbon atoms, a carbonyl group, an oxygen atom or a combination thereof are more preferred, and a single Bonding is even more preferred.
• repeating unit (3) include repeating units represented by the following formulas (3-1) to (3-15).
• R 3 has the same definition as in formula (3) above.
• the lower limit of the content of the repeating unit (3) in the total repeating units constituting the [A] polymer is preferably 10 mol%, and 15 mol%. More preferably, 20 mol % is even more preferable.
• the upper limit of the content is preferably 90 mol%, more preferably 85 mol%, and even more preferably 80 mol%.
• the polymer is a repeating unit represented by the following formula (4) (excluding the case where the above formula (1), the above formula (2) and the above formula (3)) (hereinafter referred to as "repeating unit ( 4)”).
• R 5 is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.
• L 4 is a single bond or a divalent linking group.
• Ar 1 is a monovalent group having an aromatic ring with 6 to 20 ring members.
• the term "number of ring members” refers to the number of atoms forming a ring.
• the biphenyl ring has 12 ring members
• the naphthalene ring has 10 ring members
• the fluorene ring has 13 ring members.
• the substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R 5 includes the substituted or unsubstituted C 1 to R 1 of the above formula (1).
• a group shown as a monovalent hydrocarbon group having 1 to 20 carbon atoms can be preferably employed.
• R 5 is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerizability of the monomer that gives the repeating unit (4).
• R 5 has a substituent
• preferred examples of the substituent include the substituents that R 1 in the above formula (1) can have.
• L 4 is a single bond, an alkanediyl group obtained by removing one hydrogen atom from an alkyl group having 1 to 10 carbon atoms, or a cycloalkylene group obtained by removing one hydrogen atom from a cycloalkyl group having 5 to 10 carbon atoms.
• a carbonyl group, an oxygen atom or a combination thereof are preferred, a single bond, an alkanediyl group having 1 to 5 carbon atoms, a cycloalkylene group having 5 to 7 carbon atoms, a carbonyl group, an oxygen atom or a combination thereof are more preferred, and a single Bonding is even more preferred.
• the aromatic ring having 6 to 20 ring members in Ar 1 includes, for example, aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring, indene ring and pyrene ring, pyridine ring, pyrazine ring, An aromatic heterocyclic ring such as a pyrimidine ring, a pyridazine ring, a triazine ring, or a combination thereof can be used.
• the aromatic ring of Ar 1 is at least one aromatic hydrocarbon ring selected from the group consisting of benzene ring, naphthalene ring, anthracene ring, phenalene ring, phenanthrene ring, pyrene ring, fluorene ring, perylene ring and coronene ring. is preferred, and a benzene ring, naphthalene ring or pyrene ring is more preferred.
• the monovalent group having an aromatic ring with 6 to 20 ring members represented by Ar 1 is the aromatic ring with 6 to 20 ring members in Ar 1 above, with one hydrogen atom removed. and the like are preferably mentioned.
• repeating unit (4) include repeating units represented by the following formulas (4-1) to (4-8).
• R 5 has the same definition as in formula (4) above. Among them, repeating units represented by the above formula (4-1) are preferable.
• the lower limit of the content of the repeating unit (4) in the total repeating units constituting the [A] polymer is preferably 10 mol%, and 20 mol%. More preferably, 30 mol % is even more preferable.
• the upper limit of the content is preferably 95 mol%, more preferably 90 mol%, and even more preferably 80 mol%.
• the lower limit of the weight average molecular weight of the polymer is preferably 500, more preferably 1000, even more preferably 1500, and particularly preferably 2000.
• the upper limit of the molecular weight is preferably 10,000, more preferably 9,000, even more preferably 8,000, and particularly preferably 7,000.
• the method for measuring the weight average molecular weight is described in Examples.
• the lower limit of the content of the [A] polymer in the resist underlayer film-forming composition is preferably 1% by mass, more preferably 2% by mass, based on the total mass of the [A] polymer and [C] solvent. 3% by mass is more preferred, and 4% by mass is particularly preferred.
• the upper limit of the content ratio is preferably 20% by mass, more preferably 15% by mass, still more preferably 12% by mass, and particularly preferably 10% by mass in the total mass of the [A] polymer and [C] solvent.
• the lower limit of the content of the [A] polymer in the components other than the [C] solvent in the resist underlayer film-forming composition is preferably 1% by mass, more preferably 5% by mass, and further 10% by mass. 15% by weight is particularly preferred.
• As an upper limit of the said content rate 100 mass % is preferable.
• [[A] polymer synthesis method] [A] The polymer can be synthesized by performing radical polymerization, ionic polymerization, polycondensation, polyaddition, addition condensation, etc. depending on the type of monomer. For example, when synthesizing the [A] polymer by radical polymerization, it can be synthesized by polymerizing monomers that give each structural unit in an appropriate solvent using a radical polymerization initiator or the like.
• radical polymerization initiator examples include azobisisobutyronitrile (AIBN), 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis(2-cyclopropylpropyl pionitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), azo radical initiators such as dimethyl 2,2'-azobis isobutyrate; benzoyl peroxide, t-butyl hydroperoxide, Examples include peroxide-based radical initiators such as cumene hydroperoxide. These radical initiators can be used individually by 1 type or in mixture of 2 or more types.
• the [C] solvent described later can be suitably employed.
• the solvents used for these polymerizations may be used singly or in combination of two or more.
• the reaction temperature in the above polymerization is usually 40°C to 150°C, preferably 50°C to 120°C.
• the reaction time is generally 1 hour to 48 hours, preferably 1 hour to 24 hours.
• the [C] solvent is not particularly limited as long as it can dissolve or disperse the [A] polymer and optionally contained optional components.
• Solvents include, for example, hydrocarbon solvents, ester solvents, alcohol solvents, ketone solvents, ether solvents, nitrogen-containing solvents, and the like.
• a solvent can be used individually by 1 type or in combination of 2 or more types.
• hydrocarbon solvents examples include aliphatic hydrocarbon solvents such as n-pentane, n-hexane and cyclohexane, and aromatic hydrocarbon solvents such as benzene, toluene and xylene.
• ester solvents include carbonate solvents such as diethyl carbonate, acetic acid monoester solvents such as methyl acetate and ethyl acetate, lactone solvents such as ⁇ -butyrolactone, diethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether acetate.
• carbonate solvents such as diethyl carbonate
• acetic acid monoester solvents such as methyl acetate and ethyl acetate
• lactone solvents such as ⁇ -butyrolactone
• diethylene glycol monomethyl ether acetate diethylene glycol monomethyl ether acetate
• propylene glycol monomethyl ether acetate propylene glycol monomethyl ether acetate.
• Valued alcohol partial ether carboxylate solvents such as methyl lactate and ethyl lactate, and the like are included.
• alcohol solvents examples include monoalcohol solvents such as methanol, ethanol, n-propanol and 4-methyl-2-pentanol, and polyhydric alcohol solvents such as ethylene glycol and 1,2-propylene glycol. .
• ketone solvents examples include chain ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.
• ether solvents examples include linear ether solvents such as n-butyl ether, polyhydric alcohol ether solvents such as cyclic ether solvents such as tetrahydrofuran, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether and propylene glycol monomethyl ether. Solvents and the like are included.
• nitrogen-containing solvents examples include linear nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.
• the solvent is preferably an alcohol solvent, an ether solvent or an ester solvent, more preferably a monoalcohol solvent, a polyhydric alcohol partial ether solvent or a polyhydric alcohol partial ether carboxylate solvent, and 4-methyl -2-Pentanol, propylene glycol monomethyl ether or propylene glycol monomethyl ether acetate are more preferred.
• the lower limit of the content of the [C] solvent in the composition for forming a resist underlayer film is preferably 50% by mass, more preferably 60% by mass, and even more preferably 70% by mass.
• the upper limit of the content ratio is preferably 99.9% by mass, more preferably 99% by mass, and even more preferably 95% by mass.
• the composition for forming a resist underlayer film may contain arbitrary components as long as the effects of the present invention are not impaired.
• optional components include a polymer having no sulfonic acid group, an acid generator, a cross-linking agent, a surfactant, and the like.
• An arbitrary component can be used individually by 1 type or in combination of 2 or more types.
• the content of the optional component in the composition for forming a resist underlayer film can be appropriately determined according to the type of the optional component.
• a polymer having one or a combination of two or more of the repeating units (2) to (4), and a polymer contained in the resist composition (acid dissociable group A repeating unit a having a lactone ring, a repeating unit b having a lactone ring, a repeating unit c having a polar group such as a hydroxy group (except for cases corresponding to repeating units a and b.), etc.).
• a polymer having one or a combination of two or more of the repeating units (2) to (4), and a polymer contained in the resist composition (acid dissociable group A repeating unit a having a lactone ring, a repeating unit b having a lactone ring, a repeating unit c having a polar group such as a hydroxy group (except for cases corresponding to repeating units a and b.), etc.).
• composition for forming a resist underlayer film is prepared by mixing [A] a polymer, [C] a solvent, and optionally optional components in a predetermined ratio, and preferably applying the resulting mixture to a membrane having a pore size of 0.5 ⁇ m or less. It can be prepared by filtering with a filter or the like.
• Silicon-containing film forming step In this step performed prior to the coating step (I), a silicon-containing film is formed directly or indirectly on the substrate.
• the substrate examples include metal or semi-metal substrates such as silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, and titanium substrates, among which silicon substrates are preferred.
• the substrate may be a substrate on which a silicon nitride film, an alumina film, a silicon dioxide film, a tantalum nitride film, a titanium nitride film, or the like is formed.
• a silicon-containing film can be formed by coating a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), or the like.
• CVD chemical vapor deposition
• ALD atomic layer deposition
• a method for forming a silicon-containing film by coating a silicon-containing film-forming composition for example, a coating film formed by directly or indirectly coating a substrate with a silicon-containing film-forming composition is subjected to exposure and / Or the method of hardening by heating, etc. are mentioned.
• Commercially available products of the silicon-containing film-forming composition include, for example, "NFC SOG01", “NFC SOG04", and "NFC SOG080" (manufactured by JSR Corporation).
• Silicon oxide films, silicon nitride films, silicon oxynitride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).
• Examples of the radiation used for the exposure include visible light, ultraviolet rays, far ultraviolet rays, X-rays, electromagnetic waves such as ⁇ -rays, and particle beams such as electron beams, molecular beams, and ion beams.
• the lower limit of the temperature when heating the coating film is preferably 90°C, more preferably 150°C, and even more preferably 200°C.
• the upper limit of the temperature is preferably 550°C, more preferably 450°C, and even more preferably 300°C.
• the lower limit of the average thickness of the silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 15 nm.
• the upper limit is preferably 20,000 nm, more preferably 1,000 nm, even more preferably 100 nm.
• the average thickness of the silicon-containing film can be measured in the same manner as the average thickness of the resist underlayer film.
• Forming a silicon-containing film indirectly on a substrate includes, for example, forming a silicon-containing film on a low dielectric insulating film or an organic underlayer film formed on a substrate.
• the composition for forming a resist underlayer film is applied onto the silicon-containing film formed on the substrate.
• the method of coating the composition for forming a resist underlayer film is not particularly limited, and can be carried out by an appropriate method such as spin coating, casting coating, roll coating, or the like. As a result, a coating film is formed, and [C] a resist underlayer film is formed by volatilization of the solvent.
• the silicon-containing film forming step may be omitted.
• the coating film formed by the coating is heated.
• the heating of the coating promotes the formation of the resist underlayer film. More specifically, heating the coating film promotes volatilization of the [C] solvent.
• the coating film may be heated in an air atmosphere or in a nitrogen atmosphere.
• the lower limit of the heating temperature is preferably 100°C, more preferably 150°C, and even more preferably 200°C.
• the upper limit of the heating temperature is preferably 400°C, more preferably 350°C, and even more preferably 280°C.
• the lower limit of the heating time is preferably 15 seconds, more preferably 30 seconds.
• the upper limit of the time is preferably 1,200 seconds, more preferably 600 seconds.
• the lower limit to the average thickness of the resist underlayer film to be formed is preferably 0.5 nm, more preferably 1 nm, and even more preferably 2 nm.
• the upper limit of the average thickness is preferably 50 nm, more preferably 20 nm, still more preferably 10 nm, and particularly preferably 7 nm.
• the method for measuring the average thickness is described in Examples.
• step (II) the composition for forming a resist film is applied to the resist underlayer film formed in the step of applying the composition for forming a resist underlayer film.
• the method of applying the composition for forming a resist film is not particularly limited, and examples thereof include a spin coating method.
• pre-baking (hereinafter also referred to as “PB”) is performed.
• a resist film is formed by volatilizing the solvent.
• the PB temperature and PB time can be appropriately determined according to the type of resist film forming composition used.
• the lower limit of the PB temperature is preferably 30°C, more preferably 50°C.
• the upper limit of the PB temperature is preferably 200°C, more preferably 150°C.
• the lower limit of the PB time is preferably 10 seconds, more preferably 30 seconds.
• the upper limit of the PB time is preferably 600 seconds, more preferably 300 seconds.
• the resist film-forming composition used in this step it is preferable to use a so-called positive resist film-forming composition for alkali development.
• the sulfonic acid group of the [A] polymer increases the solubility in a basic developing solution, and during development, the resist underlayer film can be removed together with the formation of a resist pattern.
• Such a composition for forming a resist film contains, for example, a resin having an acid-labile group and a radiation-sensitive acid generator, and is used for exposure with ArF excimer laser light (for ArF exposure) or exposure with extreme ultraviolet rays.
• a composition for forming a positive resist film for EUV exposure is preferred.
• the resist film formed in the resist film-forming composition coating step is exposed to radiation.
• This step causes a difference in solubility in a basic liquid, which is a developer, between an exposed portion and an unexposed portion of the resist film. More specifically, the solubility of the exposed portion of the resist film in a basic liquid increases.
• the radiation used for exposure can be appropriately selected depending on the type of resist film-forming composition used.
• Examples thereof include electromagnetic waves such as visible light, ultraviolet rays, deep ultraviolet rays, X-rays and ⁇ -rays, and particle beams such as electron beams, molecular beams and ion beams.
• far ultraviolet rays are preferable, and KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), F2 excimer laser light (wavelength 157 nm), Kr2 excimer laser light ( wavelength 147 nm), ArKr excimer laser.
• Exposure conditions can be appropriately determined according to the type of the resist film-forming composition to be used.
• PEB post-exposure bake
• the PEB temperature and PEB time can be appropriately determined according to the type of resist film-forming composition used.
• the lower limit of the PEB temperature is preferably 50°C, more preferably 70°C.
• the upper limit of the PEB temperature is preferably 200°C, more preferably 150°C.
• the lower limit of the PEB time is preferably 10 seconds, more preferably 30 seconds.
• the upper limit of the PEB time is preferably 600 seconds, more preferably 300 seconds.
• This step is preferably alkali development in which the developer used is a basic liquid. Due to the above exposure process, a difference in solubility in a basic liquid, which is a developer, occurs between the exposed area and the unexposed area of the resist film. A resist pattern is formed by removing the exposed portion where the resistance is relatively high.
• the resist underlayer film contains a polymer containing a sulfonic acid group, the solubility in a basic liquid, which is a developer, is increased, and the polymer can be removed together with the resist film in the developing step of the resist film.
• the resist underlayer film may be partially developed in the thickness direction from the outermost surface of the resist underlayer film, the entire thickness direction is developed (that is, the resist underlayer film is completely removed in the exposed portion). is more preferable.
• a part of the resist underlayer film in the plane direction may be used, and the etching process of the resist underlayer film, which is conventionally required, can be omitted by continuously developing the resist underlayer film following the resist film with a basic solution. It is possible to efficiently form a good resist pattern by reducing the number of steps and suppressing the influence on other films.
• the basic liquid for alkaline development is not particularly limited, and known basic liquids can be used.
• Basic solutions for alkali development include, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, 1,5-
• TMAH aqueous solution in which at least one alkaline compound such as diazabicyclo-[4.3.0]-5-nonene is dissolved can be mentioned.
• a TMAH aqueous solution is preferable, and a 2.38% by mass TMAH aque
• Examples of the developer used for organic solvent development include the same ones as those exemplified as the [C] solvent described above.
• washing and/or drying may be performed after the development.
• etching is performed using the resist pattern (and the resist underlayer film pattern) as a mask. Etching may be performed once or multiple times, that is, etching may be performed sequentially using a pattern obtained by etching as a mask. Multiple times are preferable from the viewpoint of obtaining a pattern with a better shape. When etching is performed multiple times, for example, the silicon-containing film and the substrate are sequentially etched. Etching methods include dry etching, wet etching, and the like. Dry etching is preferable from the viewpoint of improving the pattern shape of the substrate. For this dry etching, gas plasma such as oxygen plasma is used. A semiconductor substrate having a predetermined pattern is obtained by the etching.
• Dry etching can be performed using, for example, a known dry etching apparatus.
• the etching gas used for dry etching can be appropriately selected according to the mask pattern, the elemental composition of the film to be etched, etc. Examples include CHF 3 , CF 4 , C 2 F 6 , C 3 F 8 and SF 6 .
• Fluorine-based gases chlorine-based gases such as Cl 2 and BCl 3 , oxygen-based gases such as O 2 , O 3 and H 2 O, H 2 , NH 3 , CO, CO 2 , CH 4 , C 2 H 2 , C 2H4 , C2H6 , C3H4 , C3H6 , C3H8 , HF, HI , HBr , HCl, NO, NH3 , reducing gases such as BCl3 , He, N2 , Inert gas, such as Ar, etc. are mentioned. These gases can also be mixed and used. When etching a substrate using the pattern of the resist underlayer film as a mask, a fluorine-based gas is usually used.
• the silicon-containing film can be removed by performing the removal step described below.
• Removal step In this step, the silicon-containing film pattern is removed with a basic liquid. This step removes the silicon-containing film from the substrate. Also, the silicon-containing film residue after etching can be removed.
• Examples of basic liquids include basic liquids for alkaline development in the development process. Among these, ammonia is preferable from the viewpoint of avoiding damage to the substrate.
• the method for removing the silicon-containing film is not particularly limited as long as it is a method that allows the silicon-containing film and the basic liquid to come into contact with each other. , a method of applying a basic liquid, and the like.
• washing and/or drying may be performed after removing the silicon-containing film.
• composition for forming a resist underlayer film contains [A] polymer and [C] solvent.
• a composition for forming a resist underlayer film used in the method for manufacturing a semiconductor substrate can be suitably employed.
• Mw Weight average molecular weight
• Average thickness of film The average thickness of the film is measured using a spectroscopic ellipsometer ("M2000D" by JA WOOLLAM) at arbitrary 9 points at intervals of 5 cm including the center of the resist underlayer film. The average thickness was obtained as a calculated value.
• the start of dropping was defined as the start time of the polymerization reaction, and after the polymerization reaction was carried out for 6 hours, the mixture was cooled to 30°C or less. 300 g of 4-methyl-2-pentanol was added to the reaction solution, and isopropyl alcohol was removed by concentration under reduced pressure to obtain a 4-methyl-2-pentanol solution of polymer (A-2). The Mw of polymer (A-2) was 6,500.
• the start of dropping was defined as the start time of the polymerization reaction, and after the polymerization reaction was carried out for 6 hours, the mixture was cooled to 30°C or less. 300 g of 4-methyl-2-pentanol was added to the reaction solution, and isopropyl alcohol was removed by concentration under reduced pressure to obtain a 4-methyl-2-pentanol solution of polymer (A-3). The Mw of polymer (A-3) was 5,500.
• the start of dropping was defined as the start time of the polymerization reaction, and after the polymerization reaction was carried out for 6 hours, the mixture was cooled to 30°C or less. 300 g of propylene glycol monomethyl ether acetate was added to the reaction solution, and methyl isobutyl ketone was removed by concentration under reduced pressure to obtain a propylene glycol monomethyl ether acetate solution of polymer (B-5). The Mw of polymer (B-5) was 6,600.
• D-1 compound represented by the following formula (D-1)
• D-2 compound represented by the following formula (D-2)
• E-1 compound represented by the following formula (E-1)
• E-2 compound represented by the following formula (E-2)
• E-3 compound represented by the following formula (E-3)
• composition (J-1) 100 parts by mass of (A-1) as a polymer, [C] 1100 parts by mass of (C-2) as a solvent, (C-3) 200 parts by mass (polymer (A-1) of 4- 4-methyl-2-pentanol contained in the methyl-2-pentanol solution is also included.).
• the resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 ⁇ m to prepare composition (J-1).
• PTFE polytetrafluoroethylene
• Example 2 to 24 and Comparative Examples 1 to 3 Compositions (J-2) to (J-24) and (CJ-1) to (CJ-3) in the same manner as in Example 1, except that the types and contents of each component shown in Table 1 below were used. ) was prepared. "-" in the column “A, B, D, E” in Table 1 indicates that the corresponding component was not used.
• Solvent resistance is "A” (good) when the film thickness change rate is less than 1%, “B” (fairly good) when it is 1% or more and less than 10%, and "C” when it is 10% or more. (bad).
• the composition prepared above was applied onto a 12-inch silicon wafer by a spin coating method using a spin coater ("CLEAN TRACK ACT 12" available from Tokyo Electron Co., Ltd.). Next, in an air atmosphere, after heating at 250 ° C. for 60 seconds, by cooling at 23 ° C. for 60 seconds, a resist underlayer film having an average thickness of 5 nm is formed, and the resist with the resist underlayer film formed on the substrate A substrate with an underlayer film was obtained.
• the substrate with the resist underlayer film obtained above was immersed in a 2.38% by mass tetramethylammonium hydroxide aqueous solution (20° C. to 25° C.) for 60 seconds, washed with water, and dried to obtain a substrate for evaluation.
• the EUV exposure resist composition (R-1) comprises a structural unit (1) derived from 4-hydroxystyrene, a structural unit (2) derived from styrene, and a structural unit (3) derived from 4-t-butoxystyrene.
• 100 parts by mass of a polymer and triphenyl as a radiation-sensitive acid generator 1.0 parts by mass of sulfonium trifluoromethanesulfonate, 4,400 parts by mass of ethyl lactate and 1,900 parts by mass of propylene glycol monomethyl ether acetate as solvents are mixed, and the resulting solution is passed through a filter with a pore size of 0.2 ⁇ m. Obtained by filtration.
• An organic underlayer film forming material (“HM8006” from JSR Corporation) was applied onto a 12-inch silicon wafer by a spin coating method using a spin coater (“CLEAN TRACK ACT12” from Tokyo Electron Ltd.). C. for 60 seconds to form an organic underlayer film having an average thickness of 100 nm.
• a composition for forming a silicon-containing film (“NFC SOG080” manufactured by JSR Corporation) was applied onto the organic underlayer film, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to obtain an average thickness. A 20 nm silicon-containing film was formed. The composition prepared above was applied onto the silicon-containing film formed above, heated at 250° C.
• the EUV exposure resist composition (R-1) is applied onto the resist underlayer film formed above, heated at 130° C. for 60 seconds, and then cooled at 23° C. for 30 seconds to form a resist film having an average thickness of 50 nm. formed.
• an EUV scanner ASML "TWINSCAN NXE: 3300B" (NA 0.3, sigma 0.9, quadruple pole illumination, 1:1 line and space mask with a line width of 16 nm on the wafer) was used to create a resist film. After the extreme ultraviolet irradiation, the substrate was heated at 110° C.
• the resist underlayer films formed from the compositions of Examples have better solvent resistance, ease of removal, and pattern rectangularity than the resist underlayer films formed from the compositions of Comparative Examples. was excellent in character.
• a semiconductor substrate can be efficiently manufactured because a composition for forming a resist underlayer film capable of forming a resist underlayer film having excellent solvent resistance and pattern rectangularity is used. .
• a film excellent in solvent resistance and pattern rectangularity can be formed.
• the resist underlayer film can be removed together with the resist film in the development process in the manufacturing process of semiconductor substrates and the like, so that a film having excellent removability can be formed. be able to. Therefore, these can be suitably used for the manufacture of semiconductor devices, etc., which are expected to be further miniaturized in the future.

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  • 2022-03-09 WO PCT/JP2022/010261 patent/WO2022196485A1/ja active Application Filing
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