WO2023026779A1 - Composition for chemical mechanical polishing and polishing method - Google Patents

Composition for chemical mechanical polishing and polishing method Download PDF

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Publication number
WO2023026779A1
WO2023026779A1 PCT/JP2022/029477 JP2022029477W WO2023026779A1 WO 2023026779 A1 WO2023026779 A1 WO 2023026779A1 JP 2022029477 W JP2022029477 W JP 2022029477W WO 2023026779 A1 WO2023026779 A1 WO 2023026779A1
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Prior art keywords
chemical mechanical
mass
mechanical polishing
acid
group
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PCT/JP2022/029477
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French (fr)
Japanese (ja)
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昂輝 石牧
柊平 中村
康孝 亀井
康平 西村
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Jsr株式会社
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Publication of WO2023026779A1 publication Critical patent/WO2023026779A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B37/00—Lapping machines or devices; Accessories
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09G—POLISHING COMPOSITIONS; SKI WAXES
    • C09G1/00—Polishing compositions
    • C09G1/02—Polishing compositions containing abrasives or grinding agents
    • 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
    • C09K3/14—Anti-slip materials; Abrasives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting

Definitions

  • the present invention relates to a chemical mechanical polishing composition and a polishing method using the same.
  • CMP chemical mechanical polishing
  • CMP a chemical mechanical polishing composition is supplied onto a polishing pad attached to a surface plate, a semiconductor substrate is pressed against the polishing pad, and the semiconductor substrate and the polishing pad are slid against each other to polish the semiconductor substrate. It is a technology that chemically and mechanically polishes the In CMP, unevenness on the surface of a semiconductor substrate can be removed by chemical reaction with reagents and mechanical polishing with abrasive grains, and the surface can be planarized.
  • Some aspects of the present invention provide a chemical mechanical polishing composition capable of chemically mechanically polishing a semiconductor substrate containing ruthenium while maintaining a stable polishing rate while suppressing corrosion of ruthenium. is.
  • the present invention has been made to solve at least part of the above-mentioned problems, and can be implemented as any of the following aspects.
  • the MA (% by mass) may be 0.01 to 10% by mass.
  • the MB (% by mass) may be 0.01 to 10% by mass.
  • the pH may be 6 or more and 12 or less.
  • One aspect of the polishing method according to the present invention is A step of polishing a semiconductor substrate using the chemical mechanical polishing composition according to any one of the above aspects.
  • the semiconductor substrate may have a portion composed of at least one selected from the group consisting of ruthenium and ruthenium alloys.
  • the chemical mechanical polishing composition of the present invention it is possible to perform chemical mechanical polishing on a semiconductor substrate containing ruthenium while suppressing corrosion of ruthenium and maintaining a stable polishing rate.
  • FIG. 1 is a cross-sectional view schematically showing an object to be processed suitable for use in the polishing process according to this embodiment.
  • FIG. 2 is a cross-sectional view schematically showing the object to be processed at the end of the first polishing step.
  • FIG. 3 is a cross-sectional view schematically showing the object to be processed at the end of the second polishing step.
  • FIG. 4 is a perspective view schematically showing a chemical mechanical polishing apparatus.
  • component (A) also referred to herein as “component (A)
  • Component (A) The chemical mechanical polishing composition according to this embodiment contains abrasive grains (A).
  • Component (A) includes inorganic particles such as silica, ceria, alumina, zirconia, and titania, with silica particles being preferred.
  • silica particles include fumed silica, colloidal silica, etc. Among them, colloidal silica is preferable. Colloidal silica is preferably used from the viewpoint of reducing polishing defects such as scratches. As colloidal silica, for example, one produced by the method described in JP-A-2003-109921 can be used.
  • the component (A) is silica particles containing silica as the main component, it may further contain other components.
  • Other components include aluminum compounds, silicon compounds, and the like.
  • aluminum compounds include aluminum hydroxide, aluminum oxide (alumina), aluminum chloride, aluminum nitride, aluminum acetate, aluminum phosphate, aluminum sulfate, sodium aluminate, and potassium aluminate.
  • silicon compounds include silicon nitride, silicon carbide, silicates, silicones, silicon resins, and the like.
  • component (A) is not particularly limited, and may be spherical, cocoon-shaped, chain-spherical, or have a plurality of projections on the surface.
  • Abrasive grains having a plurality of projections on their surfaces can be produced by applying the methods described in, for example, Japanese Patent Application Laid-Open No. 2007-153732 and Japanese Patent Application Laid-Open No. 2013-121631.
  • the absolute value of the zeta potential of component (A) in the chemical mechanical polishing composition is 10 mV or more, preferably 15 mV or more, more preferably 20 mV or more.
  • the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can be polished at a more stable polishing rate. can do.
  • the zeta potential measuring device "ELSZ-2000ZS” manufactured by Otsuka Electronics Co., Ltd., "Zetasizer Ultra” manufactured by Malvern, Dispersion Technology Inc. and "DT300” manufactured by K.K.
  • the content of component (A) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, when the total mass of the chemical mechanical polishing composition is 100% by mass, Particularly preferably, it is 0.5% by mass or more.
  • the content of component (A) is preferably 10% by mass or less, more preferably 8% by mass or less, particularly preferably 5% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. % by mass or less.
  • Component (A) is preferably an abrasive grain with at least a portion of its surface modified with a functional group.
  • Abrasive grains having at least a portion of the surface modified with functional groups have a larger absolute value of zeta potential than abrasive grains not surface-modified with functional groups, so that electrostatic repulsion between abrasive grains increases. .
  • the dispersibility of the abrasive grains in the chemical mechanical polishing composition is improved, so that high-speed polishing can be performed while reducing the occurrence of polishing scratches and dishing.
  • Component (A) can have, for example, a functional group represented by the following general formula (1). - SO 3 - M + (1) (M + represents a monovalent cation.)
  • Examples of monovalent cations represented by M + in general formula (1) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + . That is, the functional group represented by the general formula (1) can be rephrased as "at least one functional group selected from the group consisting of a sulfo group and a salt thereof".
  • the "salt of a sulfo group” means that the hydrogen ion contained in the sulfo group (--SO 3 H) is replaced with a monovalent cation such as Li + , Na + , K + , NH 4 + Refers to functional groups.
  • Component (A) having a functional group represented by the general formula (1) is an abrasive grain having a functional group represented by the general formula (1) fixed to its surface via a covalent bond.
  • Abrasive grains to which a compound having a functional group represented by the general formula (1) is physically or ionically adsorbed on the surface are not included.
  • the component (A) having the functional group represented by the above general formula (1) can be produced as follows. First, silica prepared by a known method and a mercapto group-containing silane coupling agent are sufficiently stirred in an acidic medium to covalently bond the mercapto group-containing silane coupling agent to the surface of the silica. Examples of mercapto group-containing silane coupling agents include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. Next, by further adding an appropriate amount of hydrogen peroxide and allowing to stand sufficiently, the component (A) having the functional group represented by the general formula (1) can be obtained.
  • the zeta potential of the component (A) having a functional group represented by the general formula (1) is a negative potential in the chemical mechanical polishing composition, and the negative potential is preferably -10 mV or less. It is preferably -15 mV or less, and particularly preferably -20 mV or less.
  • the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can sometimes be polished at a more stable polishing rate.
  • the apparatus mentioned above can be used for a zeta-potential measuring apparatus.
  • the zeta potential of component (A) can be adjusted by appropriately increasing or decreasing the amount of the mercapto group-containing silane coupling agent or the like added.
  • the content of component (A) [MA (% by mass)] is When the total mass of the chemical mechanical polishing composition is 100 mass %, it is preferably 0.5 mass % or more, more preferably 1 mass % or more.
  • the content of component (A) [MA (% by mass)] is preferably 10% by mass or less, more preferably 5% by mass or less when the total mass of the chemical mechanical polishing composition is 100% by mass. is.
  • the content of the component (A) having a functional group represented by the general formula (1) is within the above range, a semiconductor substrate containing ruthenium can be polished at a stable polishing rate, and the chemical mechanical polishing composition can be Storage stability may be improved.
  • Component (A) can have, for example, a functional group represented by the following general formula (2). - COO - M + (2) (M + represents a monovalent cation.)
  • Examples of monovalent cations represented by M + in general formula (2) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + . That is, the functional group represented by the above general formula (2) can also be rephrased as "at least one functional group selected from the group consisting of a carboxy group and a salt thereof".
  • the term “salt of carboxyl group” refers to a functional group obtained by substituting a monovalent cation such as Li + , Na + , K + , NH 4 + for the hydrogen ion contained in the carboxyl group (-COOH). That's what I mean.
  • the component (A) having the functional group represented by the general formula (2) is an abrasive grain having the functional group represented by the general formula (2) fixed to its surface via a covalent bond. Abrasive grains to which a compound having a functional group represented by the general formula (2) is physically or ionically adsorbed on the surface are not included.
  • the component (A) having the functional group represented by the general formula (2) can be produced as follows. First, silica prepared by a known method and a carboxylic anhydride-containing silane coupling agent are sufficiently stirred in a basic medium to covalently bond the carboxylic anhydride-containing silane coupling agent to the surface of the abrasive grains. Abrasive grains having a functional group represented by the above general formula (2) can be obtained by allowing the Examples of the carboxylic anhydride-containing silane coupling agent include 3-(triethoxysilyl)propylsuccinic anhydride.
  • the zeta potential of the component (A) having a functional group represented by the general formula (2) is a negative potential in the chemical mechanical polishing composition, and the negative potential is preferably -10 mV or less. It is preferably -15 mV or less, and particularly preferably -20 mV or less.
  • the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can sometimes be polished at a more stable polishing rate.
  • the apparatus mentioned above can be used for a zeta-potential measuring apparatus.
  • the zeta potential of the component (A) having the functional group represented by the general formula (2) can be adjusted by appropriately increasing or decreasing the amount of the above-described carboxylic anhydride-containing silane coupling agent or the like added.
  • the content of the component (A) is the total mass of the chemical mechanical polishing composition. Based on 100% by mass, the content is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more.
  • the content of component (A) is preferably 10% by mass or less, more preferably 8% by mass or less, particularly preferably 5% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. % by mass or less.
  • the content of component (A) is within the above range, a semiconductor substrate containing ruthenium can be polished at a stable polishing rate, and the storage stability of the chemical mechanical polishing composition may be improved.
  • Component (A) can have, for example, a functional group represented by the following general formula (3) and/or the following general formula (4).
  • -NR 1 R 2 (3) -N + R 1 R 2 R 3 M ( 4) (In formulas (3) and (4) above, R 1 , R 2 and R 3 each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M ⁇ represents an anion. .)
  • the functional group represented by the above general formula (3) represents an amino group
  • the functional group represented by the above general formula (4) represents a salt of the amino group. Therefore, the functional group represented by the general formula (3) and the functional group represented by the general formula (4) are collectively referred to as "at least one functional group selected from the group consisting of an amino group and a salt thereof. ” can also be rephrased.
  • the component (A) having a functional group represented by the general formula (3) and/or the general formula (4) is represented by the general formula (3) and/or the general formula (4) on its surface.
  • the functional group is an abrasive grain fixed via a covalent bond, and the compound having the functional group represented by the general formula (3) and / or the general formula (4) on the surface is physically or ionic Abrasive grains such as those adsorbed to are not included.
  • the anions represented by M ⁇ are not limited to these, but anions such as OH ⁇ , F ⁇ , Cl ⁇ , Br ⁇ , I ⁇ , CN ⁇ and the like , and anions derived from acidic compounds.
  • each of R 1 to R 3 independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and two of R 1 to R 3 Two or more may combine to form a ring structure.
  • the hydrocarbon group represented by R 1 to R 3 may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an araliphatic hydrocarbon group, or an alicyclic hydrocarbon group. Moreover, the aliphatic of the aliphatic hydrocarbon group and the araliphatic hydrocarbon group may be saturated or unsaturated, and may be linear or branched. These hydrocarbon groups include, for example, linear, branched or cyclic alkyl groups, alkenyl groups, aralkyl groups, and aryl groups.
  • the alkyl group is preferably a lower alkyl group having 1 to 6 carbon atoms, more preferably a lower alkyl group having 1 to 4 carbon atoms.
  • alkyl groups include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and n-pentyl group.
  • the alkenyl group is preferably a lower alkenyl group having 1 to 6 carbon atoms, more preferably a lower alkenyl group having 1 to 4 carbon atoms.
  • alkenyl groups include vinyl groups, n-propenyl groups, iso-propenyl groups, n-butenyl groups, iso-butenyl groups, sec-butenyl groups, tert-butenyl groups and the like.
  • the aralkyl group preferably has 7 to 12 carbon atoms.
  • examples of such aralkyl groups include benzyl, phenethyl, phenylpropyl, phenylbutyl, phenylhexyl, methylbenzyl, methylphenethyl and ethylbenzyl groups.
  • the aryl group preferably has 6 to 14 carbon atoms.
  • Examples of such aryl groups include phenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2 ,6-xylyl group, 3,5-xylyl group, naphthyl group, anthryl group and the like.
  • aromatic rings of the above aryl groups and aralkyl groups may have, for example, lower alkyl groups such as methyl groups and ethyl groups, halogen atoms, nitro groups, amino groups, hydroxy groups, etc. as substituents.
  • the component (A) having a functional group represented by the general formula (3) and / or the general formula (4) is obtained by, for example, sufficiently stirring silica and an amino group-containing silane coupling agent in an acidic medium, By covalently bonding an amino group-containing silane coupling agent to the surface of silica, abrasive grains having functional groups represented by the general formula (3) and/or the general formula (4) can be produced.
  • amino group-containing silane coupling agents include 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.
  • the zeta potential of component (A) having a functional group represented by general formula (3) and/or general formula (4) is a negative potential in the chemical mechanical polishing composition, and the negative potential is It is preferably ⁇ 10 mV or less, more preferably ⁇ 15 mV or less.
  • the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can sometimes be polished at a more stable polishing rate.
  • the apparatus mentioned above can be used for a zeta-potential measuring apparatus.
  • the zeta potential of the component (A) having a functional group represented by the general formula (3) and/or the general formula (4) can be adjusted by appropriately increasing or decreasing the amount of the amino group-containing silane coupling agent or the like added. can be adjusted by
  • the component (A) is contained
  • the amount is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1% by mass when the total mass of the chemical mechanical polishing composition is 100% by mass. That's it.
  • the content of component (A) is preferably 10% by mass or less, more preferably 8% by mass or less, particularly preferably 5% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. % by mass or less.
  • the content of component (A) is within the above range, a semiconductor substrate containing ruthenium can be polished at a stable polishing rate, and the storage stability of the chemical mechanical polishing composition may be improved.
  • the chemical mechanical polishing composition according to the present embodiment contains periodate ions (IO 4 ⁇ ), hypochlorite ions (ClO ⁇ ), chlorite ions (ClO 2 ⁇ ) and hypobromite ions (BrO - ) containing an acid or a salt thereof (B) containing at least one anion selected from the group consisting of (hereinafter also referred to as "specific anion species"). It is presumed that the anion contained in component (B) functions as an oxidizing agent and oxidizes ruthenium to promote polishing.
  • component (B) include periodic acid, chlorous acid, hypochlorous acid, hypobromous acid, sodium periodate, potassium periodate, ammonium periodate, sodium chlorite, and chlorine.
  • potassium hypochlorite, sodium hypochlorite, potassium hypochlorite, sodium hypobromite and the like are preferred, and periodic acid is more preferred.
  • Component (B) may be used alone or in combination of two or more.
  • the content (mol/L) of component (B) is preferably 0.001 mol/L or more, more preferably 0.002 mol/L or more, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.003 mol/L or more.
  • the content (mol/L) of component (B) is preferably 0.05 mol/L or less, more preferably 0.04 mol/L or less, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.035 mol/L or less.
  • the content of component (B) [MB (% by mass)] is preferably 0.01% by mass or more, more preferably 0.01% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. 05% by mass or more, and particularly preferably 0.1% by mass or more.
  • the content of component (B) [MB (% by mass)] is preferably 10% by mass or less, more preferably 8% by mass or less when the total mass of the chemical mechanical polishing composition is 100% by mass. and particularly preferably 7% by mass or less.
  • the value of MA/MB is preferably 0.2 or more. , more preferably 0.25 or more, and particularly preferably 0.3 or more.
  • the value of MA/MB is preferably 50 or less, more preferably 40 or less, and particularly preferably 30 or less.
  • the chemical mechanical polishing composition according to the present embodiment may contain hydrogen peroxide (C) (also referred to herein as "component (C)"). Hydrogen peroxide (C) oxidizes ruthenium to promote polishing, and component (C) reacts with ruthenium to prevent excessive reaction between ruthenium and specific anion species contained in component (B), It has the function of suppressing the generation of halogen gas and the corrosion of ruthenium.
  • hydrogen peroxide (C) also referred to herein as “component (C)”
  • Hydrogen peroxide (C) oxidizes ruthenium to promote polishing, and component (C) reacts with ruthenium to prevent excessive reaction between ruthenium and specific anion species contained in component (B), It has the function of suppressing the generation of halogen gas and the corrosion of ruthenium.
  • the content (mol/L) of component (C) is preferably 0.0005 mol/L or more, more preferably 0.0009 mol/L or more, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.0012 mol/L or more.
  • the content (mol/L) of component (C) is preferably 0.5 mol/L or less, more preferably 0.4 mol/L or less, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.3 mol/L or less.
  • the content (% by mass) of component (C) is preferably 0.0017% by mass or more, more preferably 0.003% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. or more, particularly preferably 0.004% by mass or more.
  • the content (% by mass) of component (C) is preferably 1.7% by mass or less, more preferably 1.4% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. or less, and particularly preferably 1% by mass or less.
  • ruthenium is oxidized to promote polishing, and component (C) reacts with ruthenium to form a bond between ruthenium and the specific anion species contained in component (B). Excessive reaction can be prevented and corrosion of ruthenium can be suppressed in some cases.
  • the chemical mechanical polishing composition according to the present embodiment contains at least one functional group selected from the group consisting of amino groups and salts thereof, and at least one functional group selected from the group consisting of carboxy groups and salts thereof.
  • a compound (D) having a group also referred to herein as "component (D)" may be contained.
  • Amino groups and salts thereof include functional groups represented by the following general formula (5) or (6). -NR 4 R 5 (5) - N + R 4 R 5 R 6 M - (6) (In formulas (5) and (6) above, R 4 , R 5 and R 6 each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M ⁇ represents an anion. show.)
  • each of R 4 to R 6 independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and two of R 4 to R 6 Two or more may combine to form a ring structure.
  • the hydrocarbon groups represented by R 4 to R 6 may be aliphatic hydrocarbon groups, aromatic hydrocarbon groups, araliphatic hydrocarbon groups or alicyclic hydrocarbon groups. Moreover, the aliphatic of the aliphatic hydrocarbon group and the araliphatic hydrocarbon group may be saturated or unsaturated, and may be linear or branched. These hydrocarbon groups include, for example, linear, branched or cyclic alkyl groups, alkenyl groups, aralkyl groups, and aryl groups.
  • the alkyl group is preferably a lower alkyl group having 1 to 6 carbon atoms, more preferably a lower alkyl group having 1 to 4 carbon atoms.
  • alkyl groups include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and n-pentyl group.
  • the alkenyl group is preferably a lower alkenyl group having 1 to 6 carbon atoms, more preferably a lower alkenyl group having 1 to 4 carbon atoms.
  • alkenyl groups include vinyl groups, n-propenyl groups, iso-propenyl groups, n-butenyl groups, iso-butenyl groups, sec-butenyl groups, tert-butenyl groups and the like.
  • the aralkyl group preferably has 7 to 12 carbon atoms.
  • examples of such aralkyl groups include benzyl, phenethyl, phenylpropyl, phenylbutyl, phenylhexyl, methylbenzyl, methylphenethyl and ethylbenzyl groups.
  • the aryl group preferably has 6 to 14 carbon atoms.
  • Examples of such aryl groups include phenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2 ,6-xylyl group, 3,5-xylyl group, naphthyl group, anthryl group and the like.
  • the aromatic ring of the aryl group and the aralkyl group may have, for example, a lower alkyl group such as a methyl group or an ethyl group, a halogen atom, a nitro group, an amino group, a hydroxy group, or the like, as a substituent.
  • the carboxy group and its salt include functional groups represented by the following general formula (7).
  • - COO - M + (7) (M + represents a monovalent cation.)
  • Examples of monovalent cations represented by M + in general formula (7) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + .
  • Component (D) is a structure having at least one functional group selected from the group consisting of amino groups and salts thereof and at least one functional group selected from the group consisting of carboxy groups and salts thereof. Although not particularly limited, it preferably has a structure represented by the following general formula (8). —N(CH 2 COO — M + ) n ( R ) 2-n (8) (In formula (8) above, R 7 represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M + represents a monovalent cation. n represents an integer of 1 to 2.)
  • examples of the hydrocarbon group represented by R 7 include the same hydrocarbon groups as the hydrocarbon groups exemplified for R 4 to R 6 in general formulas (6) and (7) above. be done.
  • examples of the monovalent cation represented by M + in the general formula (8) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + .
  • the component (D) has a structure represented by the general formula (8), the component (D) is effectively coordinated to the ruthenium surface and adsorbed to form a protective film. Excessive corrosion can be suppressed.
  • Component (D) includes, for example, N-(phosphonomethyl)iminodiacetic acid, hydroxyethyliminodiacetic acid, nitrilotriacetic acid, N-(2-carboxyethyl)iminodiacetic acid, ethylenediaminetetraacetic acid, L-glutamic acid diacetic acid tetraacetic acid Sodium, glycine-N,N-bis(methylenephosphonic acid), 3,3′,3′′-nitrilotripropionic acid, glycol ether diamine tetraacetic acid, hydroxyethylethylenediamine triacetic acid, 1,3-propanediamine-N,N ,N′,N′-tetraacetic acid, triethylenetetraaminehexaacetic acid, dihydroxyethylglycine, (S,S)-ethylenediaminedisuccinic acid trihydrate, iminodiacetic acid, trans-1,2-diaminocyclohexane-N
  • the content (% by mass) of component (D) is preferably 0.05% by mass or more, more preferably 0.1% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. or more, and particularly preferably 0.15% by mass or more.
  • the content (% by mass) of component (D) is preferably 5% by mass or less, more preferably 2% by mass or less, when the total mass of the chemical mechanical polishing composition is 100% by mass, Particularly preferably, it is 1% by mass or less.
  • the chemical mechanical polishing composition according to the present embodiment contains, in addition to the components described above, a liquid medium, a water-soluble polymer, a nitrogen-containing heterocyclic compound, a surfactant, an organic acid and the like, if necessary. Salts, inorganic acids and their salts, basic compounds and the like may be contained.
  • the chemical mechanical polishing composition according to this embodiment contains a liquid medium.
  • the liquid medium includes water, a mixed medium of water and alcohol, a mixed medium containing water and an organic solvent compatible with water, and the like. Among these, it is preferable to use water or a mixed medium of water and alcohol, and it is more preferable to use water. Pure water can be preferably used as a raw material of water.
  • the liquid medium may be blended as the balance of each component described above.
  • the chemical mechanical polishing composition according to this embodiment may contain a water-soluble polymer.
  • the water-soluble polymer may adsorb to the surface of the surface to be polished, reduce polishing friction, and reduce the occurrence of dishing on the surface to be polished.
  • water-soluble polymers include polycarboxylic acid, polystyrenesulfonic acid, polyacrylic acid, polymethacrylic acid, polyether, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine, polyallylamine, and hydroxyethylcellulose. . These can be used singly or in combination of two or more.
  • the weight average molecular weight (Mw) of the water-soluble polymer is preferably 10,000 or more and 1,500,000 or less, more preferably 40,000 or more and 1,200,000 or less.
  • weight average molecular weight refers to weight average molecular weight in terms of polyethylene glycol measured by GPC (gel permeation chromatography).
  • the content of the water-soluble polymer is preferably It is 0.001% by mass or more, more preferably 0.002% by mass or more.
  • the content of the water-soluble polymer is preferably 0.1% by mass or less, more preferably 0.01% by mass or less, when the total mass of the chemical mechanical polishing composition is 100% by mass.
  • a nitrogen-containing heterocyclic compound is an organic compound containing at least one heterocyclic ring selected from five- and six-membered heterocyclic rings having at least one nitrogen atom.
  • Specific examples of the heterocyclic ring include five-membered heterocyclic rings such as pyrrole structure, imidazole structure and triazole structure; six-membered heterocyclic rings such as pyridine structure, pyrimidine structure, pyridazine structure and pyrazine structure.
  • the heterocycle may form a condensed ring.
  • an indole structure an isoindole structure, a benzimidazole structure, a benzotriazole structure, a quinoline structure, an isoquinoline structure, a quinazoline structure, a cinnoline structure, a phthalazine structure, a quinoxaline structure, and an acridine structure.
  • heterocyclic compounds having such structures heterocyclic compounds having a pyridine structure, a quinoline structure, a benzimidazole structure, and a benzotriazole structure are preferred.
  • nitrogen-containing heterocyclic compounds include aziridine, pyridine, pyrimidine, pyrrolidine, piperidine, pyrazine, triazine, pyrrole, imidazole, indole, quinoline, isoquinoline, benzoisoquinoline, purine, pteridine, triazole, triazolidine, benzotriazole, carboxy Benzotriazoles and derivatives having these skeletons are included. Among these, at least one selected from the group consisting of benzotriazole and triazole is preferred. These nitrogen-containing heterocyclic compounds may be used singly or in combination of two or more.
  • the surfactant is not particularly limited, and anionic surfactants, cationic surfactants, nonionic surfactants and the like can be used.
  • anionic surfactants include sulfates such as alkyl ether sulfates and polyoxyethylene alkylphenyl ether sulfates; and fluorine-containing surfactants such as perfluoroalkyl compounds.
  • cationic surfactants include aliphatic amine salts and aliphatic ammonium salts.
  • Nonionic surfactants include, for example, nonionic surfactants having a triple bond such as acetylene glycol, acetylene glycol ethylene oxide adducts, and acetylene alcohol; polyethylene glycol type surfactants and the like. These surfactants may be used singly or in combination of two or more.
  • the chemical mechanical polishing composition according to this embodiment may contain at least one selected from the group consisting of organic acids and salts thereof (excluding component (D)).
  • the organic acid and its salt may be able to improve the polishing rate of the semiconductor substrate containing ruthenium due to the synergistic effect with the component (A).
  • the organic acid and its salt are preferably compounds having a carboxy group and compounds having a sulfo group.
  • compounds having a carboxy group include stearic acid, lauric acid, oleic acid, myristic acid, alkenylsuccinic acid, lactic acid, tartaric acid, fumaric acid, glycolic acid, phthalic acid, maleic acid, formic acid, acetic acid, oxalic acid, citric acid, acid, malic acid, malonic acid, glutaric acid, succinic acid, benzoic acid, quinolinic acid, quinaldic acid, amidosulfuric acid, propionic acid, trifluoroacetic acid; glycine, alanine, aspartic acid, glutamic acid, lysine, arginine, tryptophan, dodecylamino amino acids such as ethylaminoethylglycine, aromatic amino acids and heterocyclic amino acids; imino acids such as alkylimin
  • Examples of compounds having a sulfo group include alkylbenzenesulfonic acids such as dodecylbenzenesulfonic acid and p-toluenesulfonic acid; alkylnaphthalenesulfonic acids such as butylnaphthalenesulfonic acid; ⁇ -olefinsulfonic acids such as tetradecenesulfonic acid; These salts are mentioned. These compounds may be used individually by 1 type, and may be used in combination of 2 or more type.
  • the content of the organic acid (salt) is It is preferably 0.001% by mass or more, more preferably 0.01% by mass or more.
  • the content of the organic acid (salt) is preferably 5% by mass or less, more preferably 1% by mass or less, when the total mass of the chemical mechanical polishing composition is 100% by mass.
  • the inorganic acid is preferably at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and salts thereof.
  • the inorganic acid may form a salt with a separately added base in the chemical mechanical polishing composition.
  • Basic compounds include organic bases and inorganic bases.
  • Preferred organic bases are amines such as triethylamine, monoethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzylamine, methylamine, ethylenediamine, diglycolamine and isopropylamine. be done.
  • examples of inorganic bases include ammonia, potassium hydroxide, sodium hydroxide and the like. Among these basic compounds, ammonia and potassium hydroxide are preferred. These basic compounds may be used individually by 1 type, and may be used in combination of 2 or more type.
  • the pH of the chemical mechanical polishing composition according to this embodiment is preferably 6.0 or higher, more preferably 6.5 or higher, and particularly preferably 7.0 or higher.
  • the pH of the chemical mechanical polishing composition according to this embodiment is preferably 12.0 or less, more preferably 11.0 or less, and particularly preferably 10.0 or less.
  • the pH of the chemical mechanical polishing composition can be adjusted, for example, by adding the aforementioned organic acid (salt), inorganic acid (salt), basic compound, or the like, and one or more of these can be used. be able to.
  • pH refers to hydrogen ion exponent, and its value can be measured using a commercially available pH meter (for example, desktop pH meter manufactured by Horiba Ltd.).
  • the chemical mechanical polishing composition according to the present embodiment can be prepared by dissolving or dispersing each component described above in a liquid medium such as water.
  • the method of dissolving or dispersing is not particularly limited, and any method may be applied as long as it can dissolve or disperse uniformly.
  • the mixing order and mixing method of the components described above are not particularly limited.
  • the chemical mechanical polishing composition can also be prepared as a concentrated type stock solution and diluted with a liquid medium such as water at the time of use.
  • a polishing method includes a step of polishing a semiconductor substrate using the chemical mechanical polishing composition described above.
  • the chemical mechanical polishing composition can chemically mechanically polish a semiconductor substrate containing ruthenium while maintaining a stable polishing rate while suppressing corrosion of ruthenium. Therefore, the semiconductor substrate, which is the object to be processed, preferably has a portion composed of at least one selected from the group consisting of ruthenium and ruthenium alloys.
  • FIG. 1 shows a cross-sectional view schematically showing an object 100 to be processed.
  • the object to be processed 100 is manufactured through the following steps (1) to (4).
  • a substrate 10 is prepared.
  • the substrate 10 may be composed of, for example, a silicon substrate and a silicon oxide film formed thereon. Furthermore, functional devices such as transistors (not shown) may be formed on the substrate 10 .
  • a silicon oxide film 12 which is an insulating film, is formed on the substrate 10 by thermal oxidation.
  • the silicon oxide film 12 is patterned. Using the obtained pattern as a mask, a wiring trench 14 is formed in the silicon oxide film 12 by photolithography.
  • a ruthenium-containing film 16 is formed on the surface of the silicon oxide film 12 and the inner wall surface of the wiring trench 14 .
  • the ruthenium-containing film 16 can be formed, for example, by chemical vapor deposition (CVD) using a ruthenium precursor, atomic layer deposition (ALD), or physical vapor deposition (PVD) such as sputtering.
  • CVD chemical vapor deposition
  • ALD atomic layer deposition
  • PVD physical vapor deposition
  • a copper film 18 having a film thickness of 10,000 to 15,000 ⁇ (“ ⁇ " means 0.1 nm) is deposited by chemical vapor deposition or electroplating.
  • ⁇ means 0.1 nm
  • the copper content in the copper-containing alloy is preferably 95% by mass or more.
  • FIG. 2 is a cross-sectional view schematically showing the object to be processed 100 at the end of the first polishing step.
  • the copper film 18 is polished using a chemical mechanical polishing composition for copper films until the ruthenium-containing film 16 is exposed.
  • the chemical mechanical polishing composition for copper films include the chemical mechanical polishing aqueous dispersion described in JP-A-2010-153790.
  • FIG. 3 is a cross-sectional view schematically showing the object to be processed 100 at the end of the second polishing step.
  • the chemical mechanical polishing composition of the present invention is used to polish part of the ruthenium-containing film 16, the copper film 18, and the silicon oxide film 12.
  • the chemical mechanical polishing composition of the present invention is used to polish part of the ruthenium-containing film 16, the copper film 18, and the silicon oxide film 12.
  • FIG. 4 is a perspective view schematically showing the polishing apparatus 200.
  • a slurry (chemical mechanical polishing composition) 44 is supplied from a slurry supply nozzle 42, and a semiconductor substrate 50 is polished while rotating a turntable 48 on which a polishing pad 46 is attached. is brought into contact with the carrier head 52 holding the . 4 also shows the water supply nozzle 54 and the dresser 56. As shown in FIG.
  • the material of the polishing pad 46 may be any of foamed polyurethane type, non-woven fabric type, and suede type, but is preferably foamed polyurethane type.
  • the polishing load of the carrier head 52 can be selected within the range of 0.7-70 psi, preferably 1.5-35 psi. Also, the rotation speed of the turntable 48 and the carrier head 52 can be appropriately selected within the range of 10 to 400 rpm, preferably 30 to 150 rpm.
  • the lower limit of the flow rate of the chemical mechanical polishing composition supplied from the slurry supply nozzle 42 is 15 mL/min, preferably 50 mL/min, and the upper limit of the flow rate is 400 mL/min, preferably 300 mL/min. minutes.
  • polishing devices examples include models “EPO-112" and “F-REX300SII” manufactured by Ebara Corporation; models “LGP-510” and “LGP-552” manufactured by Lapmaster SFT; model “LGP-552” manufactured by Applied Materials; Mirra”, “Reflexion”; Model “POLI-400L” manufactured by G&P TECHNOLOGY; Model “Reflexion LK” manufactured by AMAT.
  • Aqueous Dispersion E PL-3 manufactured by Fuso Chemical Industries, Ltd., 19.5% colloidal silica dispersion
  • the zeta potential of abrasive grains was measured using a zeta potential measuring device (manufactured by Dispersion Technology Inc., model "DT300"). Tables 1 to 3 show the results. shown together.
  • the evaluation criteria for the polishing rate of the ruthenium film are as follows. Tables 1 to 3 also show the evaluation results of the polishing rate of the ruthenium film.
  • Evaluation criteria A: When the polishing rate was 1000 nm/min or more, it was judged to be very good.
  • C When the polishing rate was less than 50 nm/min, the polishing rate was so low that it was difficult to put into practical use, so it was judged to be unsatisfactory.
  • the evaluation criteria for the etching rate of the ruthenium film are as follows. Tables 1 to 3 also show the evaluation results of the etching rate of the ruthenium film. (Evaluation criteria) A: When the etching rate was less than 1.5 nm/min, it was judged to be very good. B: When the etching rate was 1.5 nm/min or more and less than 3 nm/min, it was judged to be good because it could be put to practical use. C: When the etching rate was 3 nm/min or more, the etching rate was so high that it was difficult to put into practical use, so it was judged to be defective.
  • the evaluation criteria for the volatility are as follows. Tables 1 to 3 also show the storage stability evaluation results of the chemical mechanical polishing composition.
  • Tables 1 to 3 show the composition of the chemical mechanical polishing composition used in each example and each comparative example and each evaluation result.
  • the component (B) oxidizes ruthenium to improve the polishing rate of the ruthenium film, and ruthenium and the specific anions contained in the component (B) It can be seen that excessive reaction with seeds can be prevented and corrosion of the ruthenium film can be suppressed. Further, it can be seen that the absolute value of the zeta potential of the component (A) contained in the chemical mechanical polishing compositions of Examples 1 to 18 is 10 mV or more, thereby improving the storage stability.
  • the present invention is not limited to the above-described embodiments, and various modifications are possible.
  • the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same function, method, and result, or configurations that have the same purpose and effect).
  • the present invention includes configurations in which non-essential portions of the configurations described in the embodiments are replaced.
  • the present invention includes a configuration that achieves the same effects as the configuration described in the embodiment or a configuration that can achieve the same object.
  • the present invention includes configurations obtained by adding known techniques to the configurations described in the embodiments.
  • SYMBOLS 10 Substrate, 12... Silicon oxide film, 14... Wiring groove, 16... Ruthenium-containing film, 18... Copper film, 42... Slurry supply nozzle, 44... Slurry (chemical mechanical polishing composition), 46... Polishing pad , 48... Turntable, 50... Semiconductor substrate, 52... Carrier head, 54... Water supply nozzle, 56... Dresser, 100... Object to be processed, 200... Polishing apparatus

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Abstract

The present invention provides a composition for chemical mechanical polishing, the composition being capable of chemically mechanically polishing a semiconductor substrate that contains ruthenium, while maintaining a stable polishing rate and suppressing corrosion of ruthenium.　A composition for chemical mechanical polishing according to the present invention contains (A) abrasive grains, (B) an acid containing at least one kind of anion that is selected from the group consisting of a periodate ion (IO4 -), a hypochlorite ion (ClO-), a chlorite ion (ClO2 -) and a hypobromite ion (BrO-), or a salt thereof, and a liquid medium; if MA (% by mass) is the content of the abrasive grains (A) and MB (% by mass) is the content of the acid or a salt thereof (B), MA/MB is 0.2 to 50; and the absolute value of the zeta potential of the abrasive grains (A) in this composition for chemical mechanical polishing is 10 mV or more.

Description

化学機械研磨用組成物および研磨方法Chemical mechanical polishing composition and polishing method
　本発明は、化学機械研磨用組成物およびそれを用いた研磨方法に関する。 The present invention relates to a chemical mechanical polishing composition and a polishing method using the same.
　半導体集積回路の製造技術の向上に伴い、半導体素子の高集積化、高速動作が求められている。これに伴い、半導体素子における微細回路の製造工程において要求される半導体基板表面の平坦性はより厳しくなってきており、化学機械研磨（Chemical Mechanical Polishing：ＣＭＰ）が半導体素子の製造工程に不可欠な技術となっている。 With the improvement of semiconductor integrated circuit manufacturing technology, there is a demand for high integration and high-speed operation of semiconductor elements. Along with this, the flatness of the semiconductor substrate surface required in the manufacturing process of fine circuits in semiconductor devices is becoming more stringent, and chemical mechanical polishing (CMP) is an indispensable technology in the manufacturing process of semiconductor devices. It has become.
　ＣＭＰは、定盤上に貼り付けた研磨用パッド上に化学機械研磨用組成物を供給し、そこへ半導体基板を押し当て、半導体基板と研磨用パッドとを相互に摺動させることにより半導体基板を化学的かつ機械的に研磨する技術である。ＣＭＰでは、試薬による化学的な反応と砥粒による機械的な研磨により半導体基板表面の凹凸を削り、その表面を平坦化することができる。 In CMP, a chemical mechanical polishing composition is supplied onto a polishing pad attached to a surface plate, a semiconductor substrate is pressed against the polishing pad, and the semiconductor substrate and the polishing pad are slid against each other to polish the semiconductor substrate. It is a technology that chemically and mechanically polishes the In CMP, unevenness on the surface of a semiconductor substrate can be removed by chemical reaction with reagents and mechanical polishing with abrasive grains, and the surface can be planarized.
　近年、このようなＣＭＰを経て製造される半導体基板の銅配線を作成する際の凹部への銅の埋め込み性を改善するために、ルテニウム膜を使用する方法が検討されている（例えば、特許文献１～３参照）。 In recent years, a method of using a ruthenium film has been studied in order to improve the embedding property of copper in recesses when copper wiring is formed in a semiconductor substrate manufactured through such CMP (see, for example, Patent Documents 1-3).
特表２００９－５１４２１９号公報Japanese Patent Publication No. 2009-514219 特表２０１０－５３５４２４号公報Japanese Patent Publication No. 2010-535424 国際公開第２０１９／１５１１４５号WO2019/151145
　このようなＣＭＰにおいて、揮発性の高い四酸化ルテニウムガスの発生を抑制し、ルテニウムを含む部位を研磨するためには、塩基性の化学機械研磨用組成物と、過ヨウ素酸カリウムや次亜塩素酸カリウムのような高い酸化力を有するハロゲン系酸化剤とを用いて化学機械研磨を行う必要がある。しかしながら、塩基性の化学機械研磨用組成物を用いると、四酸化ルテニウムガスの発生を抑制できるものの、不十分に酸化した酸化ルテニウムが研磨用パッド表面に付着し、研磨用パッドの研磨特性を劣化させてしまう。その結果、ルテニウムを含む半導体基板を、安定した研磨速度を維持しながら化学機械研磨を行うことは困難となる。一方、高い酸化力を有するハロゲン系酸化剤を用いた場合、ルテニウムを腐食させてしまうおそれがある。 In such CMP, in order to suppress the generation of highly volatile ruthenium tetroxide gas and polish a portion containing ruthenium, a basic chemical mechanical polishing composition, potassium periodate and hypochlorite It is necessary to perform chemical mechanical polishing using a halogen-based oxidizing agent having high oxidizing power such as potassium acid. However, when a basic chemical mechanical polishing composition is used, generation of ruthenium tetroxide gas can be suppressed, but insufficiently oxidized ruthenium oxide adheres to the surface of the polishing pad, degrading the polishing properties of the polishing pad. Let me. As a result, it becomes difficult to chemically mechanically polish a semiconductor substrate containing ruthenium while maintaining a stable polishing rate. On the other hand, when a halogen-based oxidizing agent having high oxidizing power is used, ruthenium may be corroded.
　本発明に係る幾つかの態様は、ルテニウムの腐食を抑制しつつ、ルテニウムを含む半導体基板を安定した研磨速度を維持しながら化学機械研磨を行うことができる化学機械研磨用組成物を提供するものである。 Some aspects of the present invention provide a chemical mechanical polishing composition capable of chemically mechanically polishing a semiconductor substrate containing ruthenium while maintaining a stable polishing rate while suppressing corrosion of ruthenium. is.
　本発明は前述の課題の少なくとも一部を解決するためになされたものであり、以下のいずれかの態様として実現することができる。 The present invention has been made to solve at least part of the above-mentioned problems, and can be implemented as any of the following aspects.
　本発明に係る化学機械研磨用組成物の一態様は、
　砥粒（Ａ）と、
　過ヨウ素酸イオン（ＩＯ４ －）、次亜塩素酸イオン（ＣｌＯ－）、亜塩素酸イオン（ＣｌＯ２ －）および次亜臭素酸イオン（ＢｒＯ－）からなる群より選択される少なくとも１種のアニオンを含む酸またはその塩（Ｂ）と、
　液状媒体と、
を含有する化学機械研磨用組成物であって、
　前記砥粒（Ａ）の含有量をＭＡ（質量％）、前記酸またはその塩（Ｂ）の含有量をＭＢ（質量％）とした場合、ＭＡ／ＭＢ＝０．２～５０であり、
　前記化学機械研磨用組成物中の前記砥粒（Ａ）のゼータ電位の絶対値が１０ｍＶ以上である。 One aspect of the chemical mechanical polishing composition according to the present invention is
Abrasive grains (A);
At least one selected from the group consisting of periodate ions (IO 4 − ), hypochlorite ions (ClO − ), chlorite ions (ClO 2 − ) and hypobromite ions (BrO − ) an acid containing an anion or a salt thereof (B);
a liquid medium;
A chemical mechanical polishing composition containing
When the content of the abrasive grains (A) is MA (% by mass) and the content of the acid or salt thereof (B) is MB (% by mass), MA/MB = 0.2 to 50,
The absolute value of the zeta potential of the abrasive grains (A) in the chemical mechanical polishing composition is 10 mV or more.
　前記化学機械研磨用組成物の一態様において、
　前記ＭＡ（質量％）が０．０１～１０質量％であってもよい。 In one aspect of the chemical mechanical polishing composition,
The MA (% by mass) may be 0.01 to 10% by mass.
　前記化学機械研磨用組成物のいずれかの態様において、
　前記ＭＢ（質量％）が０．０１～１０質量％であってもよい。 In any aspect of the chemical mechanical polishing composition,
The MB (% by mass) may be 0.01 to 10% by mass.
　前記化学機械研磨用組成物のいずれかの態様において、
　ｐＨが６以上１２以下であってもよい。 In any aspect of the chemical mechanical polishing composition,
The pH may be 6 or more and 12 or less.
　本発明に係る研磨方法の一態様は、
　前記いずれかの態様の化学機械研磨用組成物を用いて半導体基板を研磨する工程を含む。 One aspect of the polishing method according to the present invention is
A step of polishing a semiconductor substrate using the chemical mechanical polishing composition according to any one of the above aspects.
　前記研磨方法の一態様において、
　前記半導体基板が、ルテニウムおよびルテニウム合金からなる群より選択される少なくとも１種により構成される部位を備えていてもよい。 In one aspect of the polishing method,
The semiconductor substrate may have a portion composed of at least one selected from the group consisting of ruthenium and ruthenium alloys.
　本発明に係る化学機械研磨用組成物によれば、ルテニウムの腐食を抑制しつつ、ルテニウムを含む半導体基板を安定した研磨速度を維持しながら化学機械研磨を行うことができる。 According to the chemical mechanical polishing composition of the present invention, it is possible to perform chemical mechanical polishing on a semiconductor substrate containing ruthenium while suppressing corrosion of ruthenium and maintaining a stable polishing rate.
図１は、本実施形態に係る研磨工程での使用に適した被処理体を模式的に示した断面図である。FIG. 1 is a cross-sectional view schematically showing an object to be processed suitable for use in the polishing process according to this embodiment. 図２は、第１研磨工程終了時での被処理体を模式的に示した断面図である。FIG. 2 is a cross-sectional view schematically showing the object to be processed at the end of the first polishing step. 図３は、第２研磨工程終了時での被処理体を模式的に示した断面図である。FIG. 3 is a cross-sectional view schematically showing the object to be processed at the end of the second polishing step. 図４は、化学機械研磨装置を模式的に示した斜視図である。FIG. 4 is a perspective view schematically showing a chemical mechanical polishing apparatus.
　以下、本発明の好適な実施形態について詳細に説明する。なお、本発明は、下記の実施形態に限定されるものではなく、本発明の要旨を変更しない範囲において実施される各種の変形例も含む。 A preferred embodiment of the present invention will be described in detail below. In addition, the present invention is not limited to the following embodiments, and includes various modifications implemented without changing the gist of the present invention.
　本明細書において、「Ａ～Ｂ」のように記載された数値範囲は、数値Ａを下限値として含み、かつ、数値Ｂを上限値として含むものとして解釈される。 In this specification, the numerical range described as "A to B" is interpreted as including the numerical value A as the lower limit and the numerical value B as the upper limit.
　１．化学機械研磨用組成物
　本発明の一実施形態に係る化学機械研磨用組成物は、砥粒（Ａ）（本明細書において、「成分（Ａ）」ともいう）と、過ヨウ素酸イオン（ＩＯ４ －）、次亜塩素酸イオン（ＣｌＯ－）、亜塩素酸イオン（ＣｌＯ２ －）および次亜臭素酸イオン（ＢｒＯ－）からなる群より選択される少なくとも１種のアニオンを含む酸またはその塩（Ｂ）（本明細書において、「成分（Ｂ）」ともいう）と、液状媒体と、を含有する化学機械研磨用組成物であって、前記砥粒（Ａ）の含有量をＭＡ（質量％）、前記酸またはその塩（Ｂ）の含有量をＭＢ（質量％）とした場合、ＭＡ／ＭＢ＝０．２～５０であり、前記化学機械研磨用組成物中の前記砥粒（Ａ）のゼータ電位の絶対値が１０ｍＶ以上である。
　以下、本実施形態に係る化学機械研磨用組成物に含まれる各成分について詳細に説明する。 1. Chemical mechanical polishing composition The chemical mechanical polishing composition according to one embodiment of the present invention comprises abrasive grains (A) (also referred to herein as “component (A)”), periodate ions (IO 4 − ), hypochlorite ion (ClO − ), chlorite ion (ClO 2 − ) and hypobromite ion (BrO − ), or an acid containing at least one anion selected from the group consisting of A chemical mechanical polishing composition containing a salt (B) (also referred to herein as "component (B)") and a liquid medium, wherein the content of the abrasive grains (A) is MA ( %), and the content of the acid or salt thereof (B) is defined as MB (% by mass), MA/MB=0.2 to 50, and the abrasive grains in the chemical mechanical polishing composition ( The absolute value of the zeta potential of A) is 10 mV or more.
Hereinafter, each component contained in the chemical mechanical polishing composition according to this embodiment will be described in detail.
　１．１．成分（Ａ）
　本実施形態に係る化学機械研磨用組成物は、砥粒（Ａ）を含有する。成分（Ａ）としては、シリカ、セリア、アルミナ、ジルコニア、チタニア等の無機粒子が挙げられるが、中でもシリカ粒子が好ましい。シリカ粒子としては、ヒュームドシリカ、コロイダルシリカ等が挙げられるが、中でもコロイダルシリカが好ましい。コロイダルシリカは、スクラッチ等の研磨欠陥を低減する観点から好ましく用いられる。コロイダルシリカとしては、例えば特開２００３－１０９９２１号公報等に記載された方法で製造されたものを使用することができる。 1.1. Component (A)
The chemical mechanical polishing composition according to this embodiment contains abrasive grains (A). Component (A) includes inorganic particles such as silica, ceria, alumina, zirconia, and titania, with silica particles being preferred. Examples of silica particles include fumed silica, colloidal silica, etc. Among them, colloidal silica is preferable. Colloidal silica is preferably used from the viewpoint of reducing polishing defects such as scratches. As colloidal silica, for example, one produced by the method described in JP-A-2003-109921 can be used.
　成分（Ａ）がシリカを主成分とするシリカ粒子の場合、さらに他の成分を含有してもよい。他の成分としては、アルミニウム化合物、ケイ素化合物等が挙げられる。シリカ粒子がアルミニウム化合物またはケイ素化合物をさらに含有することで、シリカ粒子の表面硬度を小さくすることができるため、安定した研磨速度を維持しながら、被研磨面の研磨傷やディッシングの発生をより低減できる場合がある。 When the component (A) is silica particles containing silica as the main component, it may further contain other components. Other components include aluminum compounds, silicon compounds, and the like. By further containing an aluminum compound or a silicon compound in the silica particles, the surface hardness of the silica particles can be reduced, so the occurrence of polishing scratches and dishing on the surface to be polished can be further reduced while maintaining a stable polishing rate. Sometimes we can.
　アルミニウム化合物としては、例えば、水酸化アルミニウム、酸化アルミニウム（アルミナ）、塩化アルミニウム、窒化アルミニウム、酢酸アルミニウム、リン酸アルミニウム、硫酸アルミニウム、アルミン酸ナトリウム、アルミン酸カリウム等が挙げられる。一方、ケイ素化合物としては、窒化ケイ素、炭化ケイ素、ケイ酸塩、シリコーン、ケイ素樹脂等が挙げられる。 Examples of aluminum compounds include aluminum hydroxide, aluminum oxide (alumina), aluminum chloride, aluminum nitride, aluminum acetate, aluminum phosphate, aluminum sulfate, sodium aluminate, and potassium aluminate. On the other hand, silicon compounds include silicon nitride, silicon carbide, silicates, silicones, silicon resins, and the like.
　成分（Ａ）の形状は、特に限定されず、球状であっても、繭状であっても、連鎖球状であっても、表面に複数の突起を有してもよい。表面に複数の突起を有する砥粒は、例えば特開２００７－１５３７３２号公報や特開２０１３－１２１６３１号公報に記載された方法を適用して製造することができる。 The shape of component (A) is not particularly limited, and may be spherical, cocoon-shaped, chain-spherical, or have a plurality of projections on the surface. Abrasive grains having a plurality of projections on their surfaces can be produced by applying the methods described in, for example, Japanese Patent Application Laid-Open No. 2007-153732 and Japanese Patent Application Laid-Open No. 2013-121631.
　成分（Ａ）のゼータ電位の絶対値は、化学機械研磨用組成物中において１０ｍＶ以上であり、好ましくは１５ｍＶ以上であり、より好ましくは２０ｍＶ以上である。成分（Ａ）のゼータ電位の絶対値が前記範囲にあると、砥粒間の静電反発力によって効果的に粒子同士の凝集を防ぐと共に、ルテニウムを含む半導体基板をより安定した研磨速度で研磨することができる。なお、ゼータ電位測定装置としては、大塚電子社製の「ＥＬＳＺ－２０００ＺＳ」、Ｍａｌｖｅｒｎ社製の「Ｚｅｔａｓｉｚｅｒ　Ｕｌｔｒａ」、Ｄｉｓｐｅｒｓｉｏｎ　Ｔｅｃｈｎｏｌｏｇｙ　Ｉｎｃ．製の「ＤＴ３００」等が挙げられる。 The absolute value of the zeta potential of component (A) in the chemical mechanical polishing composition is 10 mV or more, preferably 15 mV or more, more preferably 20 mV or more. When the absolute value of the zeta potential of the component (A) is within the above range, the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can be polished at a more stable polishing rate. can do. As the zeta potential measuring device, "ELSZ-2000ZS" manufactured by Otsuka Electronics Co., Ltd., "Zetasizer Ultra" manufactured by Malvern, Dispersion Technology Inc. and "DT300" manufactured by K.K.
　成分（Ａ）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．１質量％以上であり、より好ましくは０．３質量％以上であり、特に好ましくは０．５質量％以上である。成分（Ａ）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは１０質量％以下であり、より好ましくは８質量％以下であり、特に好ましくは５質量％以下である。成分（Ａ）の含有量が前記範囲にあると、ルテニウムを含む半導体基板を安定した研磨速度で研磨できると共に、化学機械研磨用組成物の保存安定性が良好となる場合がある。 The content of component (A) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, when the total mass of the chemical mechanical polishing composition is 100% by mass, Particularly preferably, it is 0.5% by mass or more. The content of component (A) is preferably 10% by mass or less, more preferably 8% by mass or less, particularly preferably 5% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. % by mass or less. When the content of component (A) is within the above range, a semiconductor substrate containing ruthenium can be polished at a stable polishing rate, and the storage stability of the chemical mechanical polishing composition may be improved.
　成分（Ａ）は、その表面の少なくとも一部が官能基によって修飾された砥粒であることが好ましい。表面の少なくとも一部が官能基によって修飾された砥粒は、官能基によって表面修飾されていない砥粒に比べてゼータ電位の絶対値が大きくなるので、砥粒同士の静電反発力が増大する。その結果、化学機械研磨用組成物中における砥粒の分散性が向上するため、研磨傷やディッシングの発生を低減しながら、高速研磨することができる。 Component (A) is preferably an abrasive grain with at least a portion of its surface modified with a functional group. Abrasive grains having at least a portion of the surface modified with functional groups have a larger absolute value of zeta potential than abrasive grains not surface-modified with functional groups, so that electrostatic repulsion between abrasive grains increases. . As a result, the dispersibility of the abrasive grains in the chemical mechanical polishing composition is improved, so that high-speed polishing can be performed while reducing the occurrence of polishing scratches and dishing.
　成分（Ａ）は、例えば、下記一般式（１）で表される官能基を有することができる。
　－ＳＯ３ －Ｍ＋　・・・・・（１）
（Ｍ＋は１価の陽イオンを表す。） Component (A) can have, for example, a functional group represented by the following general formula (1).
- SO 3 - M + (1)
(M + represents a monovalent cation.)
　上記一般式（１）中、Ｍ＋で表される１価の陽イオンとしては、これらに限定されないが、例えば、Ｈ＋、Ｌｉ＋、Ｎａ＋、Ｋ＋、ＮＨ４ ＋が挙げられる。すなわち、上記一般式（１）で表される官能基は、「スルホ基およびその塩からなる群より選択される少なくとも１種の官能基」と言い換えることもできる。ここで、「スルホ基の塩」とは、スルホ基（－ＳＯ３Ｈ）に含まれている水素イオンをＬｉ＋、Ｎａ＋、Ｋ＋、ＮＨ４ ＋等の１価の陽イオンで置換した官能基のことをいう。上記一般式（１）で表される官能基を有する成分（Ａ）は、その表面に上記一般式（１）で表される官能基が共有結合を介して固定された砥粒であり、その表面に上記一般式（１）で表される官能基を有する化合物が物理的あるいはイオン的に吸着したような砥粒は含まれない。 Examples of monovalent cations represented by M + in general formula (1) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + . That is, the functional group represented by the general formula (1) can be rephrased as "at least one functional group selected from the group consisting of a sulfo group and a salt thereof". Here, the "salt of a sulfo group" means that the hydrogen ion contained in the sulfo group (--SO 3 H) is replaced with a monovalent cation such as Li + , Na + , K + , NH 4 + Refers to functional groups. Component (A) having a functional group represented by the general formula (1) is an abrasive grain having a functional group represented by the general formula (1) fixed to its surface via a covalent bond. Abrasive grains to which a compound having a functional group represented by the general formula (1) is physically or ionically adsorbed on the surface are not included.
　上記一般式（１）で表される官能基を有する成分（Ａ）は、以下のようにして製造することができる。まず、公知の方法により作成されたシリカと、メルカプト基含有シランカップリング剤を酸性媒体中で十分に攪拌することにより、シリカの表面にメルカプト基含有シランカップリング剤を共有結合させる。ここで、メルカプト基含有シランカップリング剤としては、例えば、３－メルカプトプロピルメチルジメトキシシラン、３－メルカプトプロピルトリメトキシシラン等が挙げられる。次に、過酸化水素を更に適量添加して十分に放置することにより、上記一般式（１）で表される官能基を有する成分（Ａ）を得ることができる。 The component (A) having the functional group represented by the above general formula (1) can be produced as follows. First, silica prepared by a known method and a mercapto group-containing silane coupling agent are sufficiently stirred in an acidic medium to covalently bond the mercapto group-containing silane coupling agent to the surface of the silica. Examples of mercapto group-containing silane coupling agents include 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane. Next, by further adding an appropriate amount of hydrogen peroxide and allowing to stand sufficiently, the component (A) having the functional group represented by the general formula (1) can be obtained.
　上記一般式（１）で表される官能基を有する成分（Ａ）のゼータ電位は、化学機械研磨用組成物中において負電位であり、その負電位は、好ましくは－１０ｍＶ以下であり、より好ましくは－１５ｍＶ以下であり、特に好ましくは－２０ｍＶ以下である。成分（Ａ）のゼータ電位が前記範囲にあると、砥粒間の静電反発力によって効果的に粒子同士の凝集を防ぐと共に、ルテニウムを含む半導体基板をより安定した研磨速度で研磨できる場合がある。なお、ゼータ電位測定装置は、上述した装置を使用することができる。成分（Ａ）のゼータ電位は、上述したメルカプト基含有シランカップリング剤等の添加量を適宜増減することにより調整することができる。 The zeta potential of the component (A) having a functional group represented by the general formula (1) is a negative potential in the chemical mechanical polishing composition, and the negative potential is preferably -10 mV or less. It is preferably -15 mV or less, and particularly preferably -20 mV or less. When the zeta potential of the component (A) is within the above range, the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can sometimes be polished at a more stable polishing rate. be. In addition, the apparatus mentioned above can be used for a zeta-potential measuring apparatus. The zeta potential of component (A) can be adjusted by appropriately increasing or decreasing the amount of the mercapto group-containing silane coupling agent or the like added.
　本実施形態に係る化学機械研磨用組成物が上記一般式（１）で表される官能基を有する成分（Ａ）を含有する場合、成分（Ａ）〔ＭＡ（質量％）〕の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．５質量％以上であり、より好ましくは１質量％以上である。成分（Ａ）の含有量〔ＭＡ（質量％）〕は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは１０質量％以下であり、より好ましくは５質量％以下である。上記一般式（１）で表される官能基を有する成分（Ａ）の含有量が前記範囲であると、ルテニウムを含む半導体基板を安定した研磨速度で研磨できると共に、化学機械研磨用組成物の保存安定性が良好となる場合がある。 When the chemical mechanical polishing composition according to the present embodiment contains component (A) having a functional group represented by the general formula (1), the content of component (A) [MA (% by mass)] is When the total mass of the chemical mechanical polishing composition is 100 mass %, it is preferably 0.5 mass % or more, more preferably 1 mass % or more. The content of component (A) [MA (% by mass)] is preferably 10% by mass or less, more preferably 5% by mass or less when the total mass of the chemical mechanical polishing composition is 100% by mass. is. When the content of the component (A) having a functional group represented by the general formula (1) is within the above range, a semiconductor substrate containing ruthenium can be polished at a stable polishing rate, and the chemical mechanical polishing composition can be Storage stability may be improved.
　成分（Ａ）は、例えば、下記一般式（２）で表される官能基を有することができる。
　－ＣＯＯ－Ｍ＋　・・・・・（２）
（Ｍ＋は１価の陽イオンを表す。） Component (A) can have, for example, a functional group represented by the following general formula (2).
- COO - M + (2)
(M + represents a monovalent cation.)
　上記一般式（２）中、Ｍ＋で表される１価の陽イオンとしては、これらに限定されないが、例えば、Ｈ＋、Ｌｉ＋、Ｎａ＋、Ｋ＋、ＮＨ４ ＋が挙げられる。すなわち、上記一般式（２）で表される官能基は、「カルボキシ基およびその塩からなる群より選択される少なくとも１種の官能基」と言い換えることもできる。ここで、「カルボキシ基の塩」とは、カルボキシ基（－ＣＯＯＨ）に含まれている水素イオンをＬｉ＋、Ｎａ＋、Ｋ＋、ＮＨ４ ＋等の１価の陽イオンで置換した官能基のことをいう。上記一般式（２）で表される官能基を有する成分（Ａ）は、その表面に上記一般式（２）で表される官能基が共有結合を介して固定された砥粒であり、その表面に上記一般式（２）で表される官能基を有する化合物が物理的あるいはイオン的に吸着したような砥粒は含まれない。 Examples of monovalent cations represented by M + in general formula (2) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + . That is, the functional group represented by the above general formula (2) can also be rephrased as "at least one functional group selected from the group consisting of a carboxy group and a salt thereof". Here, the term "salt of carboxyl group" refers to a functional group obtained by substituting a monovalent cation such as Li + , Na + , K + , NH 4 + for the hydrogen ion contained in the carboxyl group (-COOH). That's what I mean. The component (A) having the functional group represented by the general formula (2) is an abrasive grain having the functional group represented by the general formula (2) fixed to its surface via a covalent bond. Abrasive grains to which a compound having a functional group represented by the general formula (2) is physically or ionically adsorbed on the surface are not included.
　上記一般式（２）で表される官能基を有する成分（Ａ）は、以下のようにして製造することができる。まず、公知の方法により作成されたシリカと、カルボン酸無水物含有シランカップリング剤とを塩基性媒体中で十分に攪拌し、砥粒の表面にカルボン酸無水物含有シランカップリング剤を共有結合させることにより、上記一般式（２）で表される官能基を有する砥粒を得ることができる。ここで、カルボン酸無水物含有シランカップリング剤としては、例えば、３－（トリエトキシシリル）プロピルコハク酸無水物等が挙げられる。 The component (A) having the functional group represented by the general formula (2) can be produced as follows. First, silica prepared by a known method and a carboxylic anhydride-containing silane coupling agent are sufficiently stirred in a basic medium to covalently bond the carboxylic anhydride-containing silane coupling agent to the surface of the abrasive grains. Abrasive grains having a functional group represented by the above general formula (2) can be obtained by allowing the Examples of the carboxylic anhydride-containing silane coupling agent include 3-(triethoxysilyl)propylsuccinic anhydride.
　上記一般式（２）で表される官能基を有する成分（Ａ）のゼータ電位は、化学機械研磨用組成物中において負電位であり、その負電位は、好ましくは－１０ｍＶ以下であり、より好ましくは－１５ｍＶ以下であり、特に好ましくは－２０ｍＶ以下である。成分（Ａ）のゼータ電位が前記範囲にあると、砥粒間の静電反発力によって効果的に粒子同士の凝集を防ぐと共に、ルテニウムを含む半導体基板をより安定した研磨速度で研磨できる場合がある。なお、ゼータ電位測定装置は、上述した装置を使用することができる。上記一般式（２）で表される官能基を有する成分（Ａ）のゼータ電位は、上述したカルボン酸無水物含有シランカップリング剤等の添加量を適宜増減することにより調整することができる。 The zeta potential of the component (A) having a functional group represented by the general formula (2) is a negative potential in the chemical mechanical polishing composition, and the negative potential is preferably -10 mV or less. It is preferably -15 mV or less, and particularly preferably -20 mV or less. When the zeta potential of the component (A) is within the above range, the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can sometimes be polished at a more stable polishing rate. be. In addition, the apparatus mentioned above can be used for a zeta-potential measuring apparatus. The zeta potential of the component (A) having the functional group represented by the general formula (2) can be adjusted by appropriately increasing or decreasing the amount of the above-described carboxylic anhydride-containing silane coupling agent or the like added.
　本実施形態に係る化学機械研磨用組成物が上記一般式（２）で表される成分（Ａ）を含有する場合、成分（Ａ）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．１質量％以上であり、より好ましくは０．３質量％以上であり、特に好ましくは０．５質量％以上である。成分（Ａ）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは１０質量％以下であり、より好ましくは８質量％以下であり、特に好ましくは５質量％以下である。成分（Ａ）の含有量が前記範囲にあると、ルテニウムを含む半導体基板を安定した研磨速度で研磨できると共に、化学機械研磨用組成物の保存安定性が良好となる場合がある。 When the chemical mechanical polishing composition according to the present embodiment contains the component (A) represented by the general formula (2), the content of the component (A) is the total mass of the chemical mechanical polishing composition. Based on 100% by mass, the content is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more. The content of component (A) is preferably 10% by mass or less, more preferably 8% by mass or less, particularly preferably 5% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. % by mass or less. When the content of component (A) is within the above range, a semiconductor substrate containing ruthenium can be polished at a stable polishing rate, and the storage stability of the chemical mechanical polishing composition may be improved.
　成分（Ａ）は、例えば、下記一般式（３）および／または下記一般式（４）で表される官能基を有することができる。
　－ＮＲ１Ｒ２　・・・・・（３）
　－Ｎ＋Ｒ１Ｒ２Ｒ３Ｍ－　・・・・・（４）
（上記式（３）および上記式（４）中、Ｒ１、Ｒ２およびＲ３は各々独立して、水素原子、または置換もしくは非置換の炭化水素基を表す。Ｍ－は陰イオンを表す。） Component (A) can have, for example, a functional group represented by the following general formula (3) and/or the following general formula (4).
-NR 1 R 2 (3)
-N + R 1 R 2 R 3 M ( 4)
(In formulas (3) and (4) above, R 1 , R 2 and R 3 each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M − represents an anion. .)
　上記一般式（３）で表される官能基はアミノ基を表しており、上記一般式（４）で表される官能基はアミノ基の塩を表している。したがって、上記一般式（３）で表される官能基と上記一般式（４）で表される官能基を纏めて、「アミノ基およびその塩からなる群より選択される少なくとも１種の官能基」と言い換えることもできる。上記一般式（３）および／または上記一般式（４）で表される官能基を有する成分（Ａ）は、その表面に上記一般式（３）および／または上記一般式（４）で表される官能基が共有結合を介して固定された砥粒であり、その表面に上記一般式（３）および／または上記一般式（４）で表される官能基を有する化合物が物理的あるいはイオン的に吸着したような砥粒は含まれない。 The functional group represented by the above general formula (3) represents an amino group, and the functional group represented by the above general formula (4) represents a salt of the amino group. Therefore, the functional group represented by the general formula (3) and the functional group represented by the general formula (4) are collectively referred to as "at least one functional group selected from the group consisting of an amino group and a salt thereof. ” can also be rephrased. The component (A) having a functional group represented by the general formula (3) and/or the general formula (4) is represented by the general formula (3) and/or the general formula (4) on its surface. The functional group is an abrasive grain fixed via a covalent bond, and the compound having the functional group represented by the general formula (3) and / or the general formula (4) on the surface is physically or ionic Abrasive grains such as those adsorbed to are not included.
　上記一般式（４）中、Ｍ－で表される陰イオンとしては、これらに限定されないが、例えば、ＯＨ－、Ｆ－、Ｃｌ－、Ｂｒ－、Ｉ－、ＣＮ－等の陰イオンの他、酸性化合物由来の陰イオンが挙げられる。 In the above general formula (4), the anions represented by M − are not limited to these, but anions such as OH − , F − , Cl − , Br − , I − , CN − and the like , and anions derived from acidic compounds.
　上記一般式（３）および上記一般式（４）中、Ｒ１～Ｒ３は各々独立して、水素原子、または置換もしくは非置換の炭化水素基を表すが、Ｒ１～Ｒ３のうち２つ以上が結合して環構造を形成していてもよい。 In general formulas (3) and (4) above, each of R 1 to R 3 independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and two of R 1 to R 3 Two or more may combine to form a ring structure.
　Ｒ１～Ｒ３で表される炭化水素基としては、脂肪族炭化水素基、芳香族炭化水素基、芳香脂肪族炭化水素基、または脂環式炭化水素基のいずれでもよい。また、脂肪族炭化水素基および芳香脂肪族炭化水素基の脂肪族は、飽和でも不飽和でもよく、直鎖状でも分岐状でもよい。これらの炭化水素基としては、例えば、直鎖状、分岐状または環状の、アルキル基、アルケニル基、アラルキル基、およびアリール基等が挙げられる。 The hydrocarbon group represented by R 1 to R 3 may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an araliphatic hydrocarbon group, or an alicyclic hydrocarbon group. Moreover, the aliphatic of the aliphatic hydrocarbon group and the araliphatic hydrocarbon group may be saturated or unsaturated, and may be linear or branched. These hydrocarbon groups include, for example, linear, branched or cyclic alkyl groups, alkenyl groups, aralkyl groups, and aryl groups.
　アルキル基としては、炭素数が１～６の低級アルキル基が好ましく、炭素数が１～４の低級アルキル基がより好ましい。このようなアルキル基としては、例えば、メチル基、エチル基、ｎ－プロピル基、ｉｓｏ－プロピル基、ｎ－ブチル基、ｉｓｏ－ブチル基、ｓｅｃ－ブチル基、ｔｅｒｔ－ブチル基、ｎ－ペンチル基、ｉｓｏ－ペンチル基、ｓｅｃ－ペンチル基、ｔｅｒｔ－ペンチル基、ネオペンチル基、ｎ－ヘキシル基、ｉｓｏ－ヘキシル基、ｓｅｃ－ヘキシル基、ｔｅｒｔ－ヘキシル基、シクロペンチル基、シクロヘキシル基等が挙げられる。 The alkyl group is preferably a lower alkyl group having 1 to 6 carbon atoms, more preferably a lower alkyl group having 1 to 4 carbon atoms. Examples of such alkyl groups include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and n-pentyl group. , iso-pentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, n-hexyl group, iso-hexyl group, sec-hexyl group, tert-hexyl group, cyclopentyl group, cyclohexyl group and the like.
　アルケニル基としては、炭素数が１～６の低級アルケニル基が好ましく、炭素数が１～４の低級アルケニル基がより好ましい。このようなアルケニル基としては、例えば、ビニル基、ｎ－プロペニル基、ｉｓｏ－プロペニル基、ｎ－ブテニル基、ｉｓｏ－ブテニル基、ｓｅｃ－ブテニル基、ｔｅｒｔ－ブテニル基等が挙げられる。 The alkenyl group is preferably a lower alkenyl group having 1 to 6 carbon atoms, more preferably a lower alkenyl group having 1 to 4 carbon atoms. Examples of such alkenyl groups include vinyl groups, n-propenyl groups, iso-propenyl groups, n-butenyl groups, iso-butenyl groups, sec-butenyl groups, tert-butenyl groups and the like.
　アラルキル基としては、炭素数が７～１２のものが好ましい。このようなアラルキル基としては、例えば、ベンジル基、フェネチル基、フェニルプロピル基、フェニルブチル基、フェニルヘキシル基、メチルベンジル基、メチルフェネチル基、エチルベンジル基等が挙げられる。 The aralkyl group preferably has 7 to 12 carbon atoms. Examples of such aralkyl groups include benzyl, phenethyl, phenylpropyl, phenylbutyl, phenylhexyl, methylbenzyl, methylphenethyl and ethylbenzyl groups.
　アリール基としては、炭素数が６～１４のものが好ましい。このようなアリール基としては、例えば、フェニル基、ｏ－トリル基、ｍ－トリル基、ｐ－トリル基、２，３－キシリル基、２，４－キシリル基、２，５－キシリル基、２，６－キシリル基、３，５－キシリル基、ナフチル基、アントリル基等が挙げられる。 The aryl group preferably has 6 to 14 carbon atoms. Examples of such aryl groups include phenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2 ,6-xylyl group, 3,5-xylyl group, naphthyl group, anthryl group and the like.
　上記のアリール基およびアラルキル基の芳香環は、例えば、メチル基、エチル基等の低級アルキル基や、ハロゲン原子、ニトロ基、アミノ基、ヒドロキシ基等を、置換基として有していてもよい。 The aromatic rings of the above aryl groups and aralkyl groups may have, for example, lower alkyl groups such as methyl groups and ethyl groups, halogen atoms, nitro groups, amino groups, hydroxy groups, etc. as substituents.
　上記一般式（３）および／または上記一般式（４）で表される官能基を有する成分（Ａ）は、例えば、シリカとアミノ基含有シランカップリング剤を酸性媒体中で十分に攪拌し、シリカの表面にアミノ基含有シランカップリング剤を共有結合させることにより、上記一般式（３）および／または上記一般式（４）で表される官能基を有する砥粒を製造することができる。ここで、アミノ基含有シランカップリング剤としては、例えば、３－アミノプロピルトリメトキシシラン、３―アミノプロピルトリエトキシシラン等が挙げられる。 The component (A) having a functional group represented by the general formula (3) and / or the general formula (4) is obtained by, for example, sufficiently stirring silica and an amino group-containing silane coupling agent in an acidic medium, By covalently bonding an amino group-containing silane coupling agent to the surface of silica, abrasive grains having functional groups represented by the general formula (3) and/or the general formula (4) can be produced. Examples of amino group-containing silane coupling agents include 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.
　上記一般式（３）および／または上記一般式（４）で表される官能基を有する成分（Ａ）のゼータ電位は、化学機械研磨用組成物中において負電位であり、その負電位は、好ましくは－１０ｍＶ以下であり、より好ましくは－１５ｍＶ以下である。成分（Ａ）のゼータ電位が前記範囲にあると、砥粒間の静電反発力によって効果的に粒子同士の凝集を防ぐと共に、ルテニウムを含む半導体基板をより安定した研磨速度で研磨できる場合がある。なお、ゼータ電位測定装置は、上述した装置を使用することができる。上記一般式（３）および／または上記一般式（４）で表される官能基を有する成分（Ａ）のゼータ電位は、上述したアミノ基含有シランカップリング剤等の添加量を適宜増減することにより調整することができる。 The zeta potential of component (A) having a functional group represented by general formula (3) and/or general formula (4) is a negative potential in the chemical mechanical polishing composition, and the negative potential is It is preferably −10 mV or less, more preferably −15 mV or less. When the zeta potential of the component (A) is within the above range, the electrostatic repulsive force between the abrasive grains effectively prevents the particles from aggregating, and the semiconductor substrate containing ruthenium can sometimes be polished at a more stable polishing rate. be. In addition, the apparatus mentioned above can be used for a zeta-potential measuring apparatus. The zeta potential of the component (A) having a functional group represented by the general formula (3) and/or the general formula (4) can be adjusted by appropriately increasing or decreasing the amount of the amino group-containing silane coupling agent or the like added. can be adjusted by
　本実施形態に係る化学機械研磨用組成物が上記一般式（３）および／または上記一般式（４）で表される官能基を有する成分（Ａ）を含有する場合、成分（Ａ）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．１質量％以上であり、より好ましくは０．５質量％以上であり、特に好ましくは１質量％以上である。成分（Ａ）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは１０質量％以下であり、より好ましくは８質量％以下であり、特に好ましくは５質量％以下である。成分（Ａ）の含有量が前記範囲であると、ルテニウムを含む半導体基板を安定した研磨速度で研磨できると共に、化学機械研磨用組成物の保存安定性が良好となる場合がある。 When the chemical mechanical polishing composition according to the present embodiment contains a component (A) having a functional group represented by the general formula (3) and/or the general formula (4), the component (A) is contained The amount is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1% by mass when the total mass of the chemical mechanical polishing composition is 100% by mass. That's it. The content of component (A) is preferably 10% by mass or less, more preferably 8% by mass or less, particularly preferably 5% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. % by mass or less. When the content of component (A) is within the above range, a semiconductor substrate containing ruthenium can be polished at a stable polishing rate, and the storage stability of the chemical mechanical polishing composition may be improved.
　１．２．成分（Ｂ）
　本実施形態に係る化学機械研磨用組成物は、過ヨウ素酸イオン（ＩＯ４ －）、次亜塩素酸イオン（ＣｌＯ－）、亜塩素酸イオン（ＣｌＯ２ －）および次亜臭素酸イオン（ＢｒＯ－）からなる群より選択される少なくとも１種のアニオン（以下、「特定アニオン種」ともいう）を含む酸またはその塩（Ｂ）を含有する。成分（Ｂ）に含まれるアニオンは、酸化剤として機能し、ルテニウムを酸化して研磨を促進するものと推測される。 1.2. Component (B)
The chemical mechanical polishing composition according to the present embodiment contains periodate ions (IO 4 − ), hypochlorite ions (ClO − ), chlorite ions (ClO 2 − ) and hypobromite ions (BrO - ) containing an acid or a salt thereof (B) containing at least one anion selected from the group consisting of (hereinafter also referred to as "specific anion species"). It is presumed that the anion contained in component (B) functions as an oxidizing agent and oxidizes ruthenium to promote polishing.
　成分（Ｂ）の具体例としては、過ヨウ素酸、亜塩素酸、次亜塩素酸、次亜臭素酸、過ヨウ素酸ナトリウム、過ヨウ素酸カリウム、過ヨウ素酸アンモニウム、亜塩素酸ナトリウム、亜塩素酸カリウム、次亜塩素酸ナトリウム、次亜塩素酸カリウム、次亜臭素酸ナトリウム等が挙げられる。これらの中でも、過ヨウ素酸、亜塩素酸カリウム、次亜塩素酸カリウムおよび次亜臭素酸ナトリウムからなる群より選択される少なくとも１種の化合物が好ましく、過ヨウ素酸がより好ましい。成分（Ｂ）は、１種単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 Specific examples of component (B) include periodic acid, chlorous acid, hypochlorous acid, hypobromous acid, sodium periodate, potassium periodate, ammonium periodate, sodium chlorite, and chlorine. potassium hypochlorite, sodium hypochlorite, potassium hypochlorite, sodium hypobromite and the like. Among these, at least one compound selected from the group consisting of periodic acid, potassium chlorite, potassium hypochlorite and sodium hypobromite is preferred, and periodic acid is more preferred. Component (B) may be used alone or in combination of two or more.
　成分（Ｂ）の含有量（ｍｏｌ／Ｌ）は、化学機械研磨用組成物１Ｌに対して、好ましくは０．００１ｍｏｌ／Ｌ以上であり、より好ましくは０．００２ｍｏｌ／Ｌ以上であり、特に好ましくは０．００３ｍｏｌ／Ｌ以上である。成分（Ｂ）の含有量（ｍｏｌ／Ｌ）は、化学機械研磨用組成物１Ｌに対して、好ましくは０．０５ｍｏｌ／Ｌ以下であり、より好ましくは０．０４ｍｏｌ／Ｌ以下であり、特に好ましくは０．０３５ｍｏｌ／Ｌ以下である。成分（Ｂ）の含有量が前記範囲にあると、ルテニウムを酸化して研磨を促進させると共に、ルテニウムと特定アニオン種との過剰な反応を防ぎ、ルテニウムの腐食を抑制できる場合がある。 The content (mol/L) of component (B) is preferably 0.001 mol/L or more, more preferably 0.002 mol/L or more, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.003 mol/L or more. The content (mol/L) of component (B) is preferably 0.05 mol/L or less, more preferably 0.04 mol/L or less, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.035 mol/L or less. When the content of component (B) is within the above range, ruthenium can be oxidized to promote polishing, and excessive reaction between ruthenium and specific anion species can be prevented, thereby suppressing corrosion of ruthenium.
　成分（Ｂ）の含有量〔ＭＢ（質量％）〕は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．０１質量％以上であり、より好ましくは０．０５質量％以上であり、特に好ましくは０．１質量％以上である。成分（Ｂ）の含有量〔ＭＢ（質量％）〕は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは１０質量％以下であり、より好ましくは８質量％以下であり、特に好ましくは７質量％以下である。成分（Ｂ）の含有量が前記範囲にあると、ルテニウムを酸化して研磨を促進させると共に、ルテニウムと特定アニオン種との過剰な反応を防ぎ、ルテニウムの腐食を抑制できる場合がある。 The content of component (B) [MB (% by mass)] is preferably 0.01% by mass or more, more preferably 0.01% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. 05% by mass or more, and particularly preferably 0.1% by mass or more. The content of component (B) [MB (% by mass)] is preferably 10% by mass or less, more preferably 8% by mass or less when the total mass of the chemical mechanical polishing composition is 100% by mass. and particularly preferably 7% by mass or less. When the content of component (B) is within the above range, ruthenium can be oxidized to promote polishing, and excessive reaction between ruthenium and specific anion species can be prevented, thereby suppressing corrosion of ruthenium.
　前記砥粒（Ａ）の含有量をＭＡ（質量％）、前記酸またはその塩（Ｂ）の含有量をＭＢ（質量％）とした場合、ＭＡ／ＭＢの値は、好ましくは０．２以上であり、より好ましくは０．２５以上であり、特に好ましくは０．３以上である。ＭＡ／ＭＢの値は、好ましくは５０以下であり、より好ましくは４０以下であり、特に好ましくは３０以下である。ＭＡ／ＭＢの値が前記範囲にあると、ルテニウムの腐食を抑制しながら、ルテニウムの研磨を促進させることができると共に、化学機械研磨用組成物の保存安定性を向上させることができる。 When the content of the abrasive grains (A) is MA (% by mass) and the content of the acid or salt thereof (B) is MB (% by mass), the value of MA/MB is preferably 0.2 or more. , more preferably 0.25 or more, and particularly preferably 0.3 or more. The value of MA/MB is preferably 50 or less, more preferably 40 or less, and particularly preferably 30 or less. When the value of MA/MB is within the above range, it is possible to promote polishing of ruthenium while suppressing corrosion of ruthenium, and to improve storage stability of the chemical mechanical polishing composition.
　１．３．成分（Ｃ）
　本実施形態に係る化学機械研磨用組成物は、過酸化水素（Ｃ）（本明細書において、「成分（Ｃ）」ともいう）を含有してもよい。過酸化水素（Ｃ）は、ルテニウムを酸化して研磨を促進させると共に、成分（Ｃ）がルテニウムと反応することでルテニウムと成分（Ｂ）に含まれる特定アニオン種との過剰な反応を防ぎ、ハロゲンガスの発生やルテニウムの腐食を抑制する機能を有する。 1.3. Component (C)
The chemical mechanical polishing composition according to the present embodiment may contain hydrogen peroxide (C) (also referred to herein as "component (C)"). Hydrogen peroxide (C) oxidizes ruthenium to promote polishing, and component (C) reacts with ruthenium to prevent excessive reaction between ruthenium and specific anion species contained in component (B), It has the function of suppressing the generation of halogen gas and the corrosion of ruthenium.
　成分（Ｃ）の含有量（ｍｏｌ／Ｌ）は、化学機械研磨用組成物１Ｌに対して、好ましくは０．０００５ｍｏｌ／Ｌ以上であり、より好ましくは０．０００９ｍｏｌ／Ｌ以上であり、特に好ましくは０．００１２ｍｏｌ／Ｌ以上である。成分（Ｃ）の含有量（ｍｏｌ／Ｌ）は、化学機械研磨用組成物１Ｌに対して、好ましくは０．５ｍｏｌ／Ｌ以下であり、より好ましくは０．４ｍｏｌ／Ｌ以下であり、特に好ましくは０．３ｍｏｌ／Ｌ以下である。成分（Ｃ）の含有量が前記範囲にあると、ルテニウムを酸化して研磨を促進させると共に、成分（Ｃ）がルテニウムと反応することでルテニウムと成分（Ｂ）に含まれる特定アニオン種との過剰な反応を防ぎ、ルテニウムの腐食を抑制できる場合がある。 The content (mol/L) of component (C) is preferably 0.0005 mol/L or more, more preferably 0.0009 mol/L or more, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.0012 mol/L or more. The content (mol/L) of component (C) is preferably 0.5 mol/L or less, more preferably 0.4 mol/L or less, and particularly preferably 1 L of the chemical mechanical polishing composition. is 0.3 mol/L or less. When the content of component (C) is within the above range, ruthenium is oxidized to promote polishing, and component (C) reacts with ruthenium to form a bond between ruthenium and the specific anion species contained in component (B). Excessive reaction can be prevented and corrosion of ruthenium can be suppressed in some cases.
　成分（Ｃ）の含有量（質量％）は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．００１７質量％以上であり、より好ましくは０．００３質量％以上であり、特に好ましくは０．００４質量％以上である。成分（Ｃ）の含有量（質量％）は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは１．７質量％以下であり、より好ましくは１．４質量％以下であり、特に好ましくは１質量％以下である。成分（Ｃ）の含有量が前記範囲にあると、ルテニウムを酸化して研磨を促進させると共に、成分（Ｃ）がルテニウムと反応することでルテニウムと成分（Ｂ）に含まれる特定アニオン種との過剰な反応を防ぎ、ルテニウムの腐食を抑制できる場合がある。 The content (% by mass) of component (C) is preferably 0.0017% by mass or more, more preferably 0.003% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. or more, particularly preferably 0.004% by mass or more. The content (% by mass) of component (C) is preferably 1.7% by mass or less, more preferably 1.4% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. or less, and particularly preferably 1% by mass or less. When the content of component (C) is within the above range, ruthenium is oxidized to promote polishing, and component (C) reacts with ruthenium to form a bond between ruthenium and the specific anion species contained in component (B). Excessive reaction can be prevented and corrosion of ruthenium can be suppressed in some cases.
　１．４．成分（Ｄ）
　本実施形態に係る化学機械研磨用組成物は、アミノ基およびその塩からなる群より選択される少なくとも１種の官能基と、カルボキシ基およびその塩からなる群より選択される少なくとも１種の官能基と、を有する化合物（Ｄ）（本明細書において、「成分（Ｄ）」ともいう）を含有してもよい。 1.4. Component (D)
The chemical mechanical polishing composition according to the present embodiment contains at least one functional group selected from the group consisting of amino groups and salts thereof, and at least one functional group selected from the group consisting of carboxy groups and salts thereof. A compound (D) having a group (also referred to herein as "component (D)") may be contained.
　アミノ基およびその塩としては、下記一般式（５）または下記一般式（６）で表される官能基が挙げられる。
　－ＮＲ４Ｒ５　・・・・・（５）
　－Ｎ＋Ｒ４Ｒ５Ｒ６Ｍ－　・・・・・（６）
（上記式（５）および上記式（６）中、Ｒ４、Ｒ５、およびＲ６は各々独立して、水素原子、または置換もしくは非置換の炭化水素基を表す。Ｍ－は陰イオンを表す。） Amino groups and salts thereof include functional groups represented by the following general formula (5) or (6).
-NR 4 R 5 (5)
- N + R 4 R 5 R 6 M - (6)
(In formulas (5) and (6) above, R 4 , R 5 and R 6 each independently represent a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M − represents an anion. show.)
　上記一般式（５）および上記一般式（６）中、Ｒ４～Ｒ６は各々独立して、水素原子、または置換もしくは非置換の炭化水素基を表すが、Ｒ４～Ｒ６のうち２つ以上が結合して環構造を形成していてもよい。 In general formulas (5) and (6) above, each of R 4 to R 6 independently represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group, and two of R 4 to R 6 Two or more may combine to form a ring structure.
　Ｒ４～Ｒ６で表される炭化水素基としては、脂肪族炭化水素基、芳香族炭化水素基、芳香脂肪族炭化水素基、または脂環式炭化水素基のいずれでもよい。また、脂肪族炭化水素基および芳香脂肪族炭化水素基の脂肪族は、飽和でも不飽和でもよく、直鎖状でも分岐状でもよい。これらの炭化水素基としては、例えば、直鎖状、分岐状または環状の、アルキル基、アルケニル基、アラルキル基、およびアリール基等が挙げられる。 The hydrocarbon groups represented by R 4 to R 6 may be aliphatic hydrocarbon groups, aromatic hydrocarbon groups, araliphatic hydrocarbon groups or alicyclic hydrocarbon groups. Moreover, the aliphatic of the aliphatic hydrocarbon group and the araliphatic hydrocarbon group may be saturated or unsaturated, and may be linear or branched. These hydrocarbon groups include, for example, linear, branched or cyclic alkyl groups, alkenyl groups, aralkyl groups, and aryl groups.
　アルキル基としては、炭素数が１～６の低級アルキル基が好ましく、炭素数が１～４の低級アルキル基がより好ましい。このようなアルキル基としては、例えば、メチル基、エチル基、ｎ－プロピル基、ｉｓｏ－プロピル基、ｎ－ブチル基、ｉｓｏ－ブチル基、ｓｅｃ－ブチル基、ｔｅｒｔ－ブチル基、ｎ－ペンチル基、ｉｓｏ－ペンチル基、ｓｅｃ－ペンチル基、ｔｅｒｔ－ペンチル基、ネオペンチル基、ｎ－ヘキシル基、ｉｓｏ－ヘキシル基、ｓｅｃ－ヘキシル基、ｔｅｒｔ－ヘキシル基、シクロペンチル基、シクロヘキシル基等が挙げられる。 The alkyl group is preferably a lower alkyl group having 1 to 6 carbon atoms, more preferably a lower alkyl group having 1 to 4 carbon atoms. Examples of such alkyl groups include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and n-pentyl group. , iso-pentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, n-hexyl group, iso-hexyl group, sec-hexyl group, tert-hexyl group, cyclopentyl group, cyclohexyl group and the like.
　アルケニル基としては、炭素数が１～６の低級アルケニル基が好ましく、炭素数が１～４の低級アルケニル基がより好ましい。このようなアルケニル基としては、例えば、ビニル基、ｎ－プロペニル基、ｉｓｏ－プロペニル基、ｎ－ブテニル基、ｉｓｏ－ブテニル基、ｓｅｃ－ブテニル基、ｔｅｒｔ－ブテニル基等が挙げられる。 The alkenyl group is preferably a lower alkenyl group having 1 to 6 carbon atoms, more preferably a lower alkenyl group having 1 to 4 carbon atoms. Examples of such alkenyl groups include vinyl groups, n-propenyl groups, iso-propenyl groups, n-butenyl groups, iso-butenyl groups, sec-butenyl groups, tert-butenyl groups and the like.
　アラルキル基としては、炭素数が７～１２のものが好ましい。このようなアラルキル基としては、例えば、ベンジル基、フェネチル基、フェニルプロピル基、フェニルブチル基、フェニルヘキシル基、メチルベンジル基、メチルフェネチル基、エチルベンジル基等が挙げられる。 The aralkyl group preferably has 7 to 12 carbon atoms. Examples of such aralkyl groups include benzyl, phenethyl, phenylpropyl, phenylbutyl, phenylhexyl, methylbenzyl, methylphenethyl and ethylbenzyl groups.
　アリール基としては、炭素数が６～１４のものが好ましい。このようなアリール基としては、例えば、フェニル基、ｏ－トリル基、ｍ－トリル基、ｐ－トリル基、２，３－キシリル基、２，４－キシリル基、２，５－キシリル基、２，６－キシリル基、３，５－キシリル基、ナフチル基、アントリル基等が挙げられる。 The aryl group preferably has 6 to 14 carbon atoms. Examples of such aryl groups include phenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2 ,6-xylyl group, 3,5-xylyl group, naphthyl group, anthryl group and the like.
　前記アリール基および前記アラルキル基の芳香環は、例えば、メチル基、エチル基等の低級アルキル基や、ハロゲン原子、ニトロ基、アミノ基、ヒドロキシ基等を、置換基として有していてもよい。 The aromatic ring of the aryl group and the aralkyl group may have, for example, a lower alkyl group such as a methyl group or an ethyl group, a halogen atom, a nitro group, an amino group, a hydroxy group, or the like, as a substituent.
　カルボキシ基およびその塩としては、下記一般式（７）で表される官能基が挙げられる。
　－ＣＯＯ－Ｍ＋　・・・・・（７）
（Ｍ＋は１価の陽イオンを表す。） The carboxy group and its salt include functional groups represented by the following general formula (7).
- COO - M + (7)
(M + represents a monovalent cation.)
　上記一般式（７）中、Ｍ＋で表される１価の陽イオンとしては、これらに限定されないが、例えば、Ｈ＋、Ｌｉ＋、Ｎａ＋、Ｋ＋、ＮＨ４ ＋が挙げられる。 Examples of monovalent cations represented by M + in general formula (7) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + .
　成分（Ｄ）は、アミノ基およびその塩からなる群より選択される少なくとも１種の官能基と、カルボキシ基およびその塩からなる群より選択される少なくとも１種の官能基とを有する構造であれば特に限定されないが、下記一般式（８）で表される構造を有することが好ましい。
　－Ｎ（ＣＨ２ＣＯＯ－Ｍ＋）ｎ（Ｒ７）２－ｎ　・・・・・（８）
（上記式（８）中、Ｒ７は水素原子、または置換もしくは非置換の炭化水素基を表す。Ｍ＋は１価の陽イオンを表す。ｎは１～２の整数を表す。） Component (D) is a structure having at least one functional group selected from the group consisting of amino groups and salts thereof and at least one functional group selected from the group consisting of carboxy groups and salts thereof. Although not particularly limited, it preferably has a structure represented by the following general formula (8).
—N(CH 2 COO — M + ) n ( R ) 2-n (8)
(In formula (8) above, R 7 represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group. M + represents a monovalent cation. n represents an integer of 1 to 2.)
　上記一般式（８）中、Ｒ７で表される炭化水素基としては、上記一般式（６）および（７）のＲ４～Ｒ６で例示した炭化水素基と同様の炭化水素基が挙げられる。上記一般式（８）中、Ｍ＋で表される１価の陽イオンとしては、これらに限定されないが、例えば、Ｈ＋、Ｌｉ＋、Ｎａ＋、Ｋ＋、ＮＨ４ ＋が挙げられる。 In general formula (8) above, examples of the hydrocarbon group represented by R 7 include the same hydrocarbon groups as the hydrocarbon groups exemplified for R 4 to R 6 in general formulas (6) and (7) above. be done. Examples of the monovalent cation represented by M + in the general formula (8) include, but are not limited to, H + , Li + , Na + , K + , and NH 4 + .
　成分（Ｄ）が上記一般式（８）で表される構造を有することにより、成分（Ｄ）がルテニウム表面に効果的に配位し、吸着して保護膜を形成することにより、ルテニウム部位の過剰な腐食を抑制することができる。 Since the component (D) has a structure represented by the general formula (8), the component (D) is effectively coordinated to the ruthenium surface and adsorbed to form a protective film. Excessive corrosion can be suppressed.
　成分（Ｄ）としては、例えば、Ｎ－（ホスホノメチル）イミノ二酢酸、ヒドロキシエチルイミノ二酢酸、ニトリロ三酢酸、Ｎ－（２－カルボキシエチル）イミノ二酢酸、エチレンジアミン四酢酸、Ｌ－グルタミン酸二酢酸四ナトリウム、グリシン－Ｎ，Ｎ－ビス（メチレンホスホン酸）、３，３’，３’’－ニトリロトリプロピオン酸、グリコールエーテルジアミン四酢酸、ヒドロキシエチルエチレンジアミン三酢酸、１，３－プロパンジアミン－Ｎ，Ｎ，Ｎ’，Ｎ’－四酢酸、トリエチレンテトラアミン六酢酸、ジヒドロキシエチルグリシン、（Ｓ，Ｓ）－エチレンジアミンジコハク酸三水和物、イミノ二酢酸、ｔｒａｎｓ－１，２－ジアミノシクロヘキサン－Ｎ，Ｎ，Ｎ’，Ｎ’－四酢酸水和物等が挙げられる。これらの成分（Ｄ）は、１種単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 Component (D) includes, for example, N-(phosphonomethyl)iminodiacetic acid, hydroxyethyliminodiacetic acid, nitrilotriacetic acid, N-(2-carboxyethyl)iminodiacetic acid, ethylenediaminetetraacetic acid, L-glutamic acid diacetic acid tetraacetic acid Sodium, glycine-N,N-bis(methylenephosphonic acid), 3,3′,3″-nitrilotripropionic acid, glycol ether diamine tetraacetic acid, hydroxyethylethylenediamine triacetic acid, 1,3-propanediamine-N,N ,N′,N′-tetraacetic acid, triethylenetetraaminehexaacetic acid, dihydroxyethylglycine, (S,S)-ethylenediaminedisuccinic acid trihydrate, iminodiacetic acid, trans-1,2-diaminocyclohexane-N , N,N',N'-tetraacetic acid hydrate and the like. These component (D) may be used individually by 1 type, and may be used in combination of 2 or more type.
　成分（Ｄ）の含有量（質量％）は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．０５質量％以上であり、より好ましくは０．１質量％以上であり、特に好ましくは０．１５質量％以上である。成分（Ｄ）の含有量（質量％）は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは５質量％以下であり、より好ましくは２質量％以下であり、特に好ましくは１質量％以下である。成分（Ｄ）の含有量が前記範囲にあると、ルテニウムを含有する半導体基板の過剰な腐食を効果的に抑制できる場合がある。 The content (% by mass) of component (D) is preferably 0.05% by mass or more, more preferably 0.1% by mass, when the total mass of the chemical mechanical polishing composition is 100% by mass. or more, and particularly preferably 0.15% by mass or more. The content (% by mass) of component (D) is preferably 5% by mass or less, more preferably 2% by mass or less, when the total mass of the chemical mechanical polishing composition is 100% by mass, Particularly preferably, it is 1% by mass or less. When the content of component (D) is within the above range, excessive corrosion of a semiconductor substrate containing ruthenium may be effectively suppressed.
　１．５．その他の成分
　本実施形態に係る化学機械研磨用組成物は、前述の各成分の他、必要に応じて、液状媒体、水溶性高分子、含窒素複素環化合物、界面活性剤、有機酸およびその塩、無機酸およびその塩、塩基性化合物等を含有してもよい。 1.5. Other Components The chemical mechanical polishing composition according to the present embodiment contains, in addition to the components described above, a liquid medium, a water-soluble polymer, a nitrogen-containing heterocyclic compound, a surfactant, an organic acid and the like, if necessary. Salts, inorganic acids and their salts, basic compounds and the like may be contained.
＜液状媒体＞
　本実施形態に係る化学機械研磨用組成物は、液状媒体を含有する。液状媒体としては、水、水およびアルコールの混合媒体、水および水との相溶性を有する有機溶媒を含む混合媒体等が挙げられる。これらの中でも、水、水およびアルコールの混合媒体を用いることが好ましく、水を用いることがより好ましい。水の原料としては純水を好ましく使用することができる。液状媒体は、前述の各成分の残部として配合されていればよい。 <Liquid medium>
The chemical mechanical polishing composition according to this embodiment contains a liquid medium. The liquid medium includes water, a mixed medium of water and alcohol, a mixed medium containing water and an organic solvent compatible with water, and the like. Among these, it is preferable to use water or a mixed medium of water and alcohol, and it is more preferable to use water. Pure water can be preferably used as a raw material of water. The liquid medium may be blended as the balance of each component described above.
＜水溶性高分子＞
　本実施形態に係る化学機械研磨用組成物は、水溶性高分子を含有してもよい。水溶性高分子は、被研磨面の表面に吸着して研磨摩擦を低減させ、被研磨面におけるディッシングの発生を低減できる場合がある。 <Water-soluble polymer>
The chemical mechanical polishing composition according to this embodiment may contain a water-soluble polymer. The water-soluble polymer may adsorb to the surface of the surface to be polished, reduce polishing friction, and reduce the occurrence of dishing on the surface to be polished.
　水溶性高分子の具体例としては、ポリカルボン酸、ポリスチレンスルホン酸、ポリアクリル酸、ポリメタクリル酸、ポリエーテル、ポリアクリルアミド、ポリビニルアルコール、ポリビニルピロリドン、ポリエチレンイミン、ポリアリルアミン、ヒドロキシエチルセルロース等が挙げられる。これらは、１種単独であるいは２種以上組み合わせて使用することができる。 Specific examples of water-soluble polymers include polycarboxylic acid, polystyrenesulfonic acid, polyacrylic acid, polymethacrylic acid, polyether, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine, polyallylamine, and hydroxyethylcellulose. . These can be used singly or in combination of two or more.
　水溶性高分子の重量平均分子量（Ｍｗ）は、好ましくは１万以上１５０万以下、より好ましくは４万以上１２０万以下である。ここで、「重量平均分子量」とは、ＧＰＣ（ゲルパーミエーションクロマトグラフィー）によって測定されたポリエチレングリコール換算の重量平均分子量のことを指す。 The weight average molecular weight (Mw) of the water-soluble polymer is preferably 10,000 or more and 1,500,000 or less, more preferably 40,000 or more and 1,200,000 or less. Here, "weight average molecular weight" refers to weight average molecular weight in terms of polyethylene glycol measured by GPC (gel permeation chromatography).
　本実施形態に係る化学機械研磨用組成物が水溶性高分子を含有する場合、水溶性高分子の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．００１質量％以上であり、より好ましくは０．００２質量％以上である。水溶性高分子の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．１質量％以下であり、より好ましくは０．０１質量％以下である。 When the chemical mechanical polishing composition according to the present embodiment contains a water-soluble polymer, the content of the water-soluble polymer is preferably It is 0.001% by mass or more, more preferably 0.002% by mass or more. The content of the water-soluble polymer is preferably 0.1% by mass or less, more preferably 0.01% by mass or less, when the total mass of the chemical mechanical polishing composition is 100% by mass.
＜含窒素複素環化合物＞
　含窒素複素環化合物は、少なくとも１個の窒素原子を有する、複素五員環および複素六員環から選択される少なくとも１種の複素環を含む有機化合物である。前記複素環の具体例としては、ピロール構造、イミダゾール構造、トリアゾール構造等の複素五員環；ピリジン構造、ピリミジン構造、ピリダジン構造、ピラジン構造等の複素六員環が挙げられる。該複素環は縮合環を形成していてもよい。具体的には、インドール構造、イソインドール構造、ベンゾイミダゾール構造、ベンゾトリアゾール構造、キノリン構造、イソキノリン構造、キナゾリン構造、シンノリン構造、フタラジン構造、キノキサリン構造、アクリジン構造等が挙げられる。このような構造を有する複素環化合物のうち、ピリジン構造、キノリン構造、ベンゾイミダゾール構造、ベンゾトリアゾール構造を有する複素環化合物が好ましい。 <Nitrogen-containing heterocyclic compound>
A nitrogen-containing heterocyclic compound is an organic compound containing at least one heterocyclic ring selected from five- and six-membered heterocyclic rings having at least one nitrogen atom. Specific examples of the heterocyclic ring include five-membered heterocyclic rings such as pyrrole structure, imidazole structure and triazole structure; six-membered heterocyclic rings such as pyridine structure, pyrimidine structure, pyridazine structure and pyrazine structure. The heterocycle may form a condensed ring. Specific examples include an indole structure, an isoindole structure, a benzimidazole structure, a benzotriazole structure, a quinoline structure, an isoquinoline structure, a quinazoline structure, a cinnoline structure, a phthalazine structure, a quinoxaline structure, and an acridine structure. Among heterocyclic compounds having such structures, heterocyclic compounds having a pyridine structure, a quinoline structure, a benzimidazole structure, and a benzotriazole structure are preferred.
　含窒素複素環化合物の具体例としては、アジリジン、ピリジン、ピリミジン、ピロリジン、ピペリジン、ピラジン、トリアジン、ピロール、イミダゾール、インドール、キノリン、イソキノリン、ベンゾイソキノリン、プリン、プテリジン、トリアゾール、トリアゾリジン、ベンゾトリアゾール、カルボキシベンゾトリアゾール、およびこれらの骨格を有する誘導体が挙げられる。これらの中でも、ベンゾトリアゾールおよびトリアゾールからなる群より選択される少なくとも１種であることが好ましい。これらの含窒素複素環化合物は、１種単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 Specific examples of nitrogen-containing heterocyclic compounds include aziridine, pyridine, pyrimidine, pyrrolidine, piperidine, pyrazine, triazine, pyrrole, imidazole, indole, quinoline, isoquinoline, benzoisoquinoline, purine, pteridine, triazole, triazolidine, benzotriazole, carboxy Benzotriazoles and derivatives having these skeletons are included. Among these, at least one selected from the group consisting of benzotriazole and triazole is preferred. These nitrogen-containing heterocyclic compounds may be used singly or in combination of two or more.
＜界面活性剤＞
　界面活性剤としては、特に制限されず、アニオン性界面活性剤、カチオン性界面活性剤、非イオン性界面活性剤等を使用することができる。アニオン性界面活性剤としては、例えば、アルキルエーテル硫酸塩、ポリオキシエチレンアルキルフェニルエーテル硫酸塩等の硫酸塩；パーフルオロアルキル化合物等の含フッ素系界面活性剤等が挙げられる。カチオン性界面活性剤としては、例えば、脂肪族アミン塩、脂肪族アンモニウム塩等が挙げられる。非イオン性界面活性剤としては、例えば、アセチレングリコール、アセチレングリコールエチレンオキサイド付加物、アセチレンアルコール等の三重結合を有する非イオン性界面活性剤；ポリエチレングリコール型界面活性剤等が挙げられる。これらの界面活性剤は、１種単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 <Surfactant>
The surfactant is not particularly limited, and anionic surfactants, cationic surfactants, nonionic surfactants and the like can be used. Examples of anionic surfactants include sulfates such as alkyl ether sulfates and polyoxyethylene alkylphenyl ether sulfates; and fluorine-containing surfactants such as perfluoroalkyl compounds. Examples of cationic surfactants include aliphatic amine salts and aliphatic ammonium salts. Nonionic surfactants include, for example, nonionic surfactants having a triple bond such as acetylene glycol, acetylene glycol ethylene oxide adducts, and acetylene alcohol; polyethylene glycol type surfactants and the like. These surfactants may be used singly or in combination of two or more.
＜有機酸およびその塩＞
　本実施形態に係る化学機械研磨用組成物は、有機酸およびその塩（前記成分（Ｄ）を除く）からなる群より選択される少なくとも１種を含有してもよい。有機酸およびその塩は、成分（Ａ）との相乗効果により、ルテニウムを含有する半導体基板の研磨速度を向上させることができる場合がある。 <Organic acid and its salt>
The chemical mechanical polishing composition according to this embodiment may contain at least one selected from the group consisting of organic acids and salts thereof (excluding component (D)). The organic acid and its salt may be able to improve the polishing rate of the semiconductor substrate containing ruthenium due to the synergistic effect with the component (A).
　有機酸およびその塩としては、カルボキシ基を有する化合物、スルホ基を有する化合物であることが好ましい。カルボキシ基を有する化合物としては、例えば、ステアリン酸、ラウリン酸、オレイン酸、ミリスチン酸、アルケニルコハク酸、乳酸、酒石酸、フマル酸、グリコール酸、フタル酸、マレイン酸、ギ酸、酢酸、シュウ酸、クエン酸、リンゴ酸、マロン酸、グルタル酸、コハク酸、安息香酸、キノリン酸、キナルジン酸、アミド硫酸、プロピオン酸、トリフルオロ酢酸；グリシン、アラニン、アスパラギン酸、グルタミン酸、リシン、アルギニン、トリプトファン、ドデシルアミノエチルアミノエチルグリシン、芳香族アミノ酸、複素環型アミノ酸等のアミノ酸；アルキルイミノジカルボン酸等のイミノ酸；およびこれらの塩が挙げられる。スルホ基を有する化合物としては、例えば、ドデシルベンゼンスルホン酸、ｐ－トルエンスルホン酸等のアルキルベンゼンスルホン酸；ブチルナフタレンスルホン酸等のアルキルナフタレンスルホン酸；テトラデセンスルホン酸等のα－オレフィンスルホン酸；およびこれらの塩が挙げられる。これらの化合物は、１種単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 The organic acid and its salt are preferably compounds having a carboxy group and compounds having a sulfo group. Examples of compounds having a carboxy group include stearic acid, lauric acid, oleic acid, myristic acid, alkenylsuccinic acid, lactic acid, tartaric acid, fumaric acid, glycolic acid, phthalic acid, maleic acid, formic acid, acetic acid, oxalic acid, citric acid, acid, malic acid, malonic acid, glutaric acid, succinic acid, benzoic acid, quinolinic acid, quinaldic acid, amidosulfuric acid, propionic acid, trifluoroacetic acid; glycine, alanine, aspartic acid, glutamic acid, lysine, arginine, tryptophan, dodecylamino amino acids such as ethylaminoethylglycine, aromatic amino acids and heterocyclic amino acids; imino acids such as alkyliminodicarboxylic acids; and salts thereof. Examples of compounds having a sulfo group include alkylbenzenesulfonic acids such as dodecylbenzenesulfonic acid and p-toluenesulfonic acid; alkylnaphthalenesulfonic acids such as butylnaphthalenesulfonic acid; α-olefinsulfonic acids such as tetradecenesulfonic acid; These salts are mentioned. These compounds may be used individually by 1 type, and may be used in combination of 2 or more type.
　本実施形態に係る化学機械研磨用組成物が有機酸（塩）を含有する場合、有機酸（塩）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは０．００１質量％以上であり、より好ましくは０．０１質量％以上である。有機酸（塩）の含有量は、化学機械研磨用組成物の全質量を１００質量％としたときに、好ましくは５質量％以下であり、より好ましくは１質量％以下である。 When the chemical mechanical polishing composition according to the present embodiment contains an organic acid (salt), the content of the organic acid (salt) is It is preferably 0.001% by mass or more, more preferably 0.01% by mass or more. The content of the organic acid (salt) is preferably 5% by mass or less, more preferably 1% by mass or less, when the total mass of the chemical mechanical polishing composition is 100% by mass.
＜無機酸およびその塩＞
　無機酸としては、塩酸、硝酸、硫酸、リン酸、およびこれらの塩からなる群より選択される少なくとも１種であることが好ましい。なお、無機酸は、化学機械研磨用組成物中で別途添加した塩基と塩を形成してもよい。 <Inorganic acid and its salt>
The inorganic acid is preferably at least one selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and salts thereof. The inorganic acid may form a salt with a separately added base in the chemical mechanical polishing composition.
＜塩基性化合物＞
　塩基性化合物としては、有機塩基および無機塩基が挙げられる。有機塩基としては、アミンが好ましく、例えばトリエチルアミン、モノエタノールアミン、テトラメチルアンモニウムヒドロキシド、テトラエチルアンモニウムヒドロキシド、テトラブチルアンモニウムヒドロキシド、ベンジルアミン、メチルアミン、エチレンジアミン、ジグリコールアミン、イソプロピルアミン等が挙げられる。無機塩基としては、例えばアンモニア、水酸化カリウム、水酸化ナトリウム等が挙げられる。これらの塩基性化合物の中でも、アンモニア、水酸化カリウムが好ましい。これらの塩基性化合物は、１種単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 <Basic compound>
Basic compounds include organic bases and inorganic bases. Preferred organic bases are amines such as triethylamine, monoethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzylamine, methylamine, ethylenediamine, diglycolamine and isopropylamine. be done. Examples of inorganic bases include ammonia, potassium hydroxide, sodium hydroxide and the like. Among these basic compounds, ammonia and potassium hydroxide are preferred. These basic compounds may be used individually by 1 type, and may be used in combination of 2 or more type.
　１．６．ｐＨ
　本実施形態に係る化学機械研磨用組成物のｐＨは、好ましくは６．０以上であり、より好ましくは６．５以上であり、特に好ましくは７．０以上である。本実施形態に係る化学機械研磨用組成物のｐＨは、好ましくは１２．０以下であり、より好ましくは１１．０以下であり、特に好ましくは１０．０以下である。ｐＨが前記範囲であると、四酸化ルテニウムガスの発生やルテニウムの腐食を効果的に抑制できる場合がある。 1.6. pH
The pH of the chemical mechanical polishing composition according to this embodiment is preferably 6.0 or higher, more preferably 6.5 or higher, and particularly preferably 7.0 or higher. The pH of the chemical mechanical polishing composition according to this embodiment is preferably 12.0 or less, more preferably 11.0 or less, and particularly preferably 10.0 or less. When the pH is within the above range, the generation of ruthenium tetroxide gas and the corrosion of ruthenium can be effectively suppressed in some cases.
　なお、化学機械研磨用組成物のｐＨは、例えば、前述の有機酸（塩）、無機酸（塩）、塩基性化合物等を添加することにより調整することができ、これらの１種以上を用いることができる。 The pH of the chemical mechanical polishing composition can be adjusted, for example, by adding the aforementioned organic acid (salt), inorganic acid (salt), basic compound, or the like, and one or more of these can be used. be able to.
　本発明において、ｐＨは、水素イオン指数のことを指し、その値は、市販のｐＨメーター（例えば、堀場製作所社製、卓上型ｐＨメーター）を用いて測定することができる。 In the present invention, pH refers to hydrogen ion exponent, and its value can be measured using a commercially available pH meter (for example, desktop pH meter manufactured by Horiba Ltd.).
　１．７．化学機械研磨用組成物の調製方法
　本実施形態に係る化学機械研磨用組成物は、水等の液状媒体に前述した各成分を溶解または分散させることにより調製することができる。溶解または分散させる方法は、特に制限されず、均一に溶解または分散できればどのような方法を適用してもよい。また、前述した各成分の混合順序や混合方法についても特に制限されない。 1.7. Method for Preparing Chemical Mechanical Polishing Composition The chemical mechanical polishing composition according to the present embodiment can be prepared by dissolving or dispersing each component described above in a liquid medium such as water. The method of dissolving or dispersing is not particularly limited, and any method may be applied as long as it can dissolve or disperse uniformly. Also, the mixing order and mixing method of the components described above are not particularly limited.
　また、化学機械研磨用組成物は、濃縮タイプの原液として調製し、使用時に水等の液状媒体で希釈して使用することもできる。 The chemical mechanical polishing composition can also be prepared as a concentrated type stock solution and diluted with a liquid medium such as water at the time of use.
　２．研磨方法
　本発明の一実施形態に係る研磨方法は、前述の化学機械研磨用組成物を用いて半導体基板を研磨する工程を含む。該化学機械研磨用組成物は、ルテニウムの腐食を抑制しつつ、ルテニウムを含む半導体基板を安定した研磨速度を維持しながら化学機械研磨を行うことができる。そのため、被処理体たる半導体基板は、ルテニウムおよびルテニウム合金からなる群より選択される少なくとも１種により構成される部位を備えていることが好ましい。以下、図１～図４を参照しながら、本実施形態に係る研磨方法について詳細に説明する。 2. Polishing Method A polishing method according to an embodiment of the present invention includes a step of polishing a semiconductor substrate using the chemical mechanical polishing composition described above. The chemical mechanical polishing composition can chemically mechanically polish a semiconductor substrate containing ruthenium while maintaining a stable polishing rate while suppressing corrosion of ruthenium. Therefore, the semiconductor substrate, which is the object to be processed, preferably has a portion composed of at least one selected from the group consisting of ruthenium and ruthenium alloys. Hereinafter, the polishing method according to this embodiment will be described in detail with reference to FIGS. 1 to 4. FIG.
　ルテニウムおよびルテニウム合金からなる群より選択される少なくとも１種により構成される部位を備えた半導体基板としては、例えば図１に示すような被処理体１００が挙げられる。図１に、被処理体１００を模式的に示した断面図を示す。被処理体１００は、以下の工程（１）～（４）を経ることにより作製される。 An example of a semiconductor substrate having a portion composed of at least one selected from the group consisting of ruthenium and ruthenium alloys is an object 100 to be processed as shown in FIG. FIG. 1 shows a cross-sectional view schematically showing an object 100 to be processed. The object to be processed 100 is manufactured through the following steps (1) to (4).
　（１）まず、図１に示すように、基体１０を用意する。基体１０は、例えばシリコン基板とその上に形成された酸化シリコン膜とから構成されていてもよい。さらに、基体１０には、（図示しない）トランジスタ等の機能デバイスが形成されていてもよい。次に、基体１０の上に、熱酸化法を用いて絶縁膜である酸化シリコン膜１２を形成する。 (1) First, as shown in FIG. 1, a substrate 10 is prepared. The substrate 10 may be composed of, for example, a silicon substrate and a silicon oxide film formed thereon. Furthermore, functional devices such as transistors (not shown) may be formed on the substrate 10 . Next, a silicon oxide film 12, which is an insulating film, is formed on the substrate 10 by thermal oxidation.
　（２）次いで、酸化シリコン膜１２をパターニングする。得られたパターンをマスクとして、フォトリソグラフィー法により酸化シリコン膜１２に配線用溝１４を形成する。 (2) Next, the silicon oxide film 12 is patterned. Using the obtained pattern as a mask, a wiring trench 14 is formed in the silicon oxide film 12 by photolithography.
　（３）次いで、酸化シリコン膜１２の表面および配線用溝１４の内壁面にルテニウム含有膜１６を形成する。ルテニウム含有膜１６は、例えば、ルテニウムプレカーサを用いた化学気相成長法（ＣＶＤ）や原子層堆積法（ＡＬＤ）、またはスパッタリングなどの物理気相堆積法（ＰＶＤ）により形成することができる。 (3) Next, a ruthenium-containing film 16 is formed on the surface of the silicon oxide film 12 and the inner wall surface of the wiring trench 14 . The ruthenium-containing film 16 can be formed, for example, by chemical vapor deposition (CVD) using a ruthenium precursor, atomic layer deposition (ALD), or physical vapor deposition (PVD) such as sputtering.
　（４）次いで、化学蒸着法または電気めっき法により、膜厚１０，０００～１５，０００Å（ここで、「Å」とは０．１ｎｍのことを指す）の銅膜１８を堆積させる。銅膜１８の材料としては、純度の高い銅だけでなく、銅を含有する合金を使用することもできる。銅を含有する合金中の銅含有量としては、９５質量％以上であることが好ましい。 (4) Next, a copper film 18 having a film thickness of 10,000 to 15,000 Å ("Å" means 0.1 nm) is deposited by chemical vapor deposition or electroplating. As the material of the copper film 18, not only high-purity copper but also an alloy containing copper can be used. The copper content in the copper-containing alloy is preferably 95% by mass or more.
　続いて、被処理体１００の第１研磨工程を行う。図２は、第１研磨工程終了時での被処理体１００を模式的に示した断面図である。図２に示すように、第１研磨工程では、銅膜用の化学機械研磨用組成物を用いてルテニウム含有膜１６が露出するまで銅膜１８を研磨する。銅膜用の化学機械研磨用組成物としては、例えば特開２０１０－１５３７９０号公報に記載された化学機械研磨用水系分散体が挙げられる。 Then, the first polishing process for the object 100 to be processed is performed. FIG. 2 is a cross-sectional view schematically showing the object to be processed 100 at the end of the first polishing step. As shown in FIG. 2, in the first polishing step, the copper film 18 is polished using a chemical mechanical polishing composition for copper films until the ruthenium-containing film 16 is exposed. Examples of the chemical mechanical polishing composition for copper films include the chemical mechanical polishing aqueous dispersion described in JP-A-2010-153790.
　続いて、被処理体１００の第２研磨工程を行う。図３は、第２研磨工程終了時での被処理体１００を模式的に示した断面図である。図３に示すように、第２研磨工程では、本発明の化学機械研磨用組成物を用いてルテニウム含有膜１６、銅膜１８、および酸化シリコン膜１２の一部を研磨する。 Then, the second polishing process for the object 100 to be processed is performed. FIG. 3 is a cross-sectional view schematically showing the object to be processed 100 at the end of the second polishing step. As shown in FIG. 3, in the second polishing step, the chemical mechanical polishing composition of the present invention is used to polish part of the ruthenium-containing film 16, the copper film 18, and the silicon oxide film 12. As shown in FIG.
　第１研磨工程および第２研磨工程には、例えば図４に示すような研磨装置２００を用いることができる。図４は、研磨装置２００を模式的に示した斜視図である。第１研磨工程および第２研磨工程は、スラリー供給ノズル４２からスラリー（化学機械研磨用組成物）４４を供給し、かつ研磨用パッド４６が貼付されたターンテーブル４８を回転させながら、半導体基板５０を保持したキャリアーヘッド５２を当接させることにより行う。なお、図４には、水供給ノズル５４およびドレッサー５６も併せて示してある。 For the first polishing process and the second polishing process, for example, a polishing apparatus 200 as shown in FIG. 4 can be used. FIG. 4 is a perspective view schematically showing the polishing apparatus 200. As shown in FIG. In the first polishing process and the second polishing process, a slurry (chemical mechanical polishing composition) 44 is supplied from a slurry supply nozzle 42, and a semiconductor substrate 50 is polished while rotating a turntable 48 on which a polishing pad 46 is attached. is brought into contact with the carrier head 52 holding the . 4 also shows the water supply nozzle 54 and the dresser 56. As shown in FIG.
　研磨用パッド４６の材質は、発泡ポリウレタンタイプ、不織布タイプ、スウェードタイプの何れであってもよいが、発泡ポリウレタンタイプであることが好ましい。 The material of the polishing pad 46 may be any of foamed polyurethane type, non-woven fabric type, and suede type, but is preferably foamed polyurethane type.
　キャリアーヘッド５２の研磨荷重は、０．７～７０ｐｓｉの範囲内で選択することができ、好ましくは１．５～３５ｐｓｉである。また、ターンテーブル４８およびキャリアーヘッド５２の回転数は１０～４００ｒｐｍの範囲内で適宜選択することができ、好ましくは３０～１５０ｒｐｍである。スラリー供給ノズル４２から供給される化学機械研磨用組成物の流量の下限値は１５ｍＬ／分であり、好ましくは５０ｍＬ／分であり、その流量の上限値は４００ｍＬ／分であり、好ましくは３００ｍＬ／分である。 The polishing load of the carrier head 52 can be selected within the range of 0.7-70 psi, preferably 1.5-35 psi. Also, the rotation speed of the turntable 48 and the carrier head 52 can be appropriately selected within the range of 10 to 400 rpm, preferably 30 to 150 rpm. The lower limit of the flow rate of the chemical mechanical polishing composition supplied from the slurry supply nozzle 42 is 15 mL/min, preferably 50 mL/min, and the upper limit of the flow rate is 400 mL/min, preferably 300 mL/min. minutes.
　市販の研磨装置としては、例えば、荏原製作所製、型式「ＥＰＯ－１１２」、「Ｆ－ＲＥＸ３００ＳＩＩ」；ラップマスターＳＦＴ製、型式「ＬＧＰ－５１０」、「ＬＧＰ－５５２」；アプライドマテリアル製、型式「Ｍｉｒｒａ」、「Ｒｅｆｌｅｘｉｏｎ」；Ｇ＆Ｐ　ＴＥＣＨＮＯＬＯＧＹ製、型式「ＰＯＬＩ－４００Ｌ」；ＡＭＡＴ製、型式「Ｒｅｆｌｅｘｉｏｎ　ＬＫ」等が挙げられる。 Examples of commercially available polishing devices include models "EPO-112" and "F-REX300SII" manufactured by Ebara Corporation; models "LGP-510" and "LGP-552" manufactured by Lapmaster SFT; model "LGP-552" manufactured by Applied Materials; Mirra", "Reflexion"; Model "POLI-400L" manufactured by G&P TECHNOLOGY; Model "Reflexion LK" manufactured by AMAT.
　３．実施例
　以下、本発明を実施例により説明するが、本発明はこれらの実施例により何ら限定されるものではない。なお、本実施例における「部」および「％」は、特に断らない限り質量基準である。 3. Examples Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples. "Parts" and "%" in the examples are based on mass unless otherwise specified.
　３．１．シリカ粒子水分散体の調製
　３．１．１．水分散体Ａの調製
　ＰＬ－３（扶桑化学工業社製、１９．５％コロイダルシリカ分散液）２０００ｇに２５％アンモニア水（富士フイルム和光純薬社製）を添加し、ｐＨ９に調整した。その後、（３－トリエトキシシリル）メルカプト基含有シランカップリング剤（商品名「ＫＢＭ－８０３」、信越化学工業社製）３．９ｇを滴下し、６０℃で２時間撹拌した。その後、過酸化水素（富士フイルム和光純薬社製）５０ｇを添加し、常圧下で８時間還流し、平均粒子径５８ｎｍのスルホ基で表面修飾された繭型のシリカ粒子を含む水分散体Ａを得た。 3.1. Preparation of silica particle aqueous dispersion 3.1.1. Preparation of Aqueous Dispersion A To 2000 g of PL-3 (19.5% colloidal silica dispersion manufactured by Fuso Chemical Industry Co., Ltd.) was adjusted to pH 9 by adding 25% aqueous ammonia (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.). After that, 3.9 g of a (3-triethoxysilyl)mercapto group-containing silane coupling agent (trade name “KBM-803” manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise and stirred at 60° C. for 2 hours. Then, 50 g of hydrogen peroxide (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was added and refluxed for 8 hours under normal pressure. got
　３．１．２．水分散体Ｂの調製
　ＰＬ－３（扶桑化学工業社製、１９．５％コロイダルシリカ分散液）２０００ｇを６０℃に加熱した。その後、（３－トリエトキシシリル）プロピルコハク酸無水物（東京化成工業社製）１５．５ｇを加え、さらに６０℃で４時間撹拌し、平均粒子径６０ｎｍのカルボキシ基で表面修飾された繭型のシリカ粒子を含む水分散体Ｂを得た。 3.1.2. Preparation of Water Dispersion B 2000 g of PL-3 (19.5% colloidal silica dispersion manufactured by Fuso Chemical Industry Co., Ltd.) was heated to 60°C. After that, 15.5 g of (3-triethoxysilyl) propylsuccinic anhydride (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added, and the mixture was stirred at 60°C for 4 hours. to obtain a water dispersion B containing silica particles.
　３．１．３．水分散体Ｃの調製
　メタノール７０ｇと３－アミノプロピルトリエトキシシラン（東京化成工業社製）１１．３ｇの混合液を、ＰＬ－３（扶桑化学工業社製、１９．５％コロイダルシリカ分散液）２０００ｇへ滴下し、常圧下で２時間還流を行った。その後、容量を一定に保ちつつ純水を滴下し、塔頂温が１００℃に達した時点で純水の滴下を終了し、平均粒子径５６ｎｍのアミノ基で表面修飾された繭型のシリカ粒子を含む水分散体Ｃを得た。 3.1.3. Preparation of water dispersion C A mixture of 70 g of methanol and 11.3 g of 3-aminopropyltriethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to PL-3 (manufactured by Fuso Chemical Industry Co., Ltd., 19.5% colloidal silica dispersion). It was added dropwise to 2000 g and refluxed under normal pressure for 2 hours. After that, pure water is added dropwise while keeping the volume constant, and when the tower top temperature reaches 100 ° C., the drop of pure water is terminated, and cocoon-shaped silica particles surface-modified with amino groups having an average particle diameter of 56 nm. A water dispersion C containing was obtained.
　３．１．４．水分散体Ｄの調製
　ＰＬ－２Ｌ（扶桑化学工業社製、２０％コロイダルシリカ分散液）１９５０ｇに２５％アンモニア水（富士フイルム和光純薬社製）を添加し、ｐＨ９に調整した。その後、（３－トリエトキシシリル）メルカプト基含有シランカップリング剤（商品名「ＫＢＭ－８０３」、信越化学工業社製）３．９ｇを滴下し、６０℃で２時間撹拌した。その後、過酸化水素（富士フイルム和光純薬社製）５０ｇを添加し、常圧下で８時間還流し、平均粒子径２３ｎｍのスルホ基で表面修飾された球型のシリカ粒子を含む水分散体Ｄを得た。 3.1.4. Preparation of Aqueous Dispersion D To 1950 g of PL-2L (manufactured by Fuso Chemical Industry Co., Ltd., 20% colloidal silica dispersion), 25% aqueous ammonia (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was added to adjust the pH to 9. After that, 3.9 g of a (3-triethoxysilyl)mercapto group-containing silane coupling agent (trade name “KBM-803” manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise and stirred at 60° C. for 2 hours. After that, 50 g of hydrogen peroxide (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was added and refluxed for 8 hours under normal pressure. got
　３．１．５．水分散体Ｅの調製
　ＰＬ－３（扶桑化学工業社製、１９．５％コロイダルシリカ分散液）をそのまま、平均粒子径６０ｎｍの表面修飾されていないシリカ粒子を含む水分散体Ｅとして使用した。 3.1.5. Preparation of Aqueous Dispersion E PL-3 (manufactured by Fuso Chemical Industries, Ltd., 19.5% colloidal silica dispersion) was used as it was as Aqueous Dispersion E containing unmodified silica particles with an average particle size of 60 nm.
　３．２．化学機械研磨用組成物の調製
　表１～表３に示す組成となるように各成分を混合し、さらに表１～表３に示すｐＨとなるように水酸化カリウム水溶液（関東化学社製、商品名「４８％水酸化カリウム水溶液」）とリン酸（富士フイルム和光純薬社製、商品名「りん酸」）を必要に応じて添加して調整し、全成分の合計量が１００質量％となるように純水を添加して、各実施例および各比較例の化学機械研磨用組成物を調製した。このようにして得られた各化学機械研磨用組成物について、ゼータ電位測定装置（Ｄｉｓｐｅｒｓｉｏｎ　Ｔｅｃｈｎｏｌｏｇｙ　Ｉｎｃ．製、型式「ＤＴ３００」）を用いて砥粒のゼータ電位を測定した結果を表１～表３に併せて示す。 3.2. Preparation of chemical mechanical polishing composition Each component was mixed so as to have the composition shown in Tables 1 to 3, and a potassium hydroxide aqueous solution (manufactured by Kanto Kagaku Co., Ltd., product Name "48% potassium hydroxide aqueous solution") and phosphoric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "phosphoric acid") are added and adjusted as necessary, and the total amount of all components is 100% by mass. Pure water was added so that the chemical mechanical polishing composition of each example and each comparative example was prepared. For each chemical mechanical polishing composition thus obtained, the zeta potential of abrasive grains was measured using a zeta potential measuring device (manufactured by Dispersion Technology Inc., model "DT300"). Tables 1 to 3 show the results. shown together.
　３．３．評価方法
　３．３．１．研磨速度評価
　上記で調製した化学機械研磨用組成物を用いて、直径１２インチのルテニウム膜１００ｎｍ付きウエハを被研磨体として、下記の条件で化学機械研磨試験を行った。
（研磨条件）
・研磨装置：荏原製作所社製、型式「Ｆ－ＲＥＸ３００ＳＩＩ」
・研磨パッド：デュポン社製、「多孔質ポリウレタン製パッド；Ｏｐｔｉｖｉｓｉоｎ９５００　ＣＭＰ　Ｐｏｌｉｓｈｉｎｇ　ｐａｄ」
・化学機械研磨用組成物供給速度：２５０ｍＬ／分
・定盤回転数：１００ｒｐｍ
・ヘッド回転数：９０ｒｐｍ
・ヘッド押し付け圧：２ｐｓｉ
・研磨時間：６０秒
・研磨速度（ｎｍ／分）＝（研磨前の膜の厚さ（ｎｍ）－研磨後の膜の厚さ（ｎｍ））／研磨時間（分） 3.3. Evaluation method 3.3.1. Evaluation of Polishing Rate Using the chemical mechanical polishing composition prepared above, a chemical mechanical polishing test was conducted under the following conditions using a wafer having a diameter of 12 inches and having a ruthenium film of 100 nm as an object to be polished.
(polishing conditions)
・Polishing device: Model “F-REX300SII” manufactured by Ebara Corporation
・Polishing pad: “Porous polyurethane pad; Optivision 9500 CMP Polishing pad” manufactured by DuPont
・Chemical mechanical polishing composition supply rate: 250 mL/min ・Surface plate rotation speed: 100 rpm
・Head rotation speed: 90 rpm
・Head pressing pressure: 2 psi
・Polishing time: 60 seconds ・Polishing rate (nm/min) = (thickness of film before polishing (nm) - thickness of film after polishing (nm))/polishing time (min)
　なお、ルテニウム膜の厚さは、抵抗率測定機（ケーエルエー・テンコール社製、型式「ＲＳ－１００」）により直流４探針法で抵抗を測定し、このシート抵抗値とルテニウムの体積抵抗率から下記式によって算出した。
　ルテニウム膜の厚さ（ｎｍ）＝［ルテニウム膜の体積抵抗率（Ω・ｍ）÷シート抵抗値（Ω／ｓｑ）］×１０９ The thickness of the ruthenium film is determined by measuring the resistance by the DC 4-probe method using a resistivity measuring device (manufactured by KLA-Tencor Co., Ltd., model "RS-100"). It was calculated by the following formula.
Thickness of ruthenium film (nm)=[volume resistivity of ruthenium film (Ω·m)÷sheet resistance value (Ω/sq)]×10 9
　ルテニウム膜の研磨速度の評価基準は下記の通りである。ルテニウム膜の研磨速度の評価結果を表１～表３に併せて示す。
（評価基準）
Ａ：研磨速度が１０００ｎｍ／分以上である場合、非常に良好と判断した。
Ｂ：研磨速度が５０ｎｍ／分以上１０００ｎｍ／分未満である場合、実用に供することができるので良好と判断した。
Ｃ：研磨速度が５０ｎｍ／分未満である場合、研磨速度が小さく実用困難であるため不良と判断した。 The evaluation criteria for the polishing rate of the ruthenium film are as follows. Tables 1 to 3 also show the evaluation results of the polishing rate of the ruthenium film.
(Evaluation criteria)
A: When the polishing rate was 1000 nm/min or more, it was judged to be very good.
B: When the polishing rate was 50 nm/min or more and less than 1000 nm/min, it was judged to be good because it could be put to practical use.
C: When the polishing rate was less than 50 nm/min, the polishing rate was so low that it was difficult to put into practical use, so it was judged to be unsatisfactory.
　３．３．２．エッチング速度評価
　上記で調製した化学機械研磨用組成物を６０℃に昇温し、３０ｍｍ×１０ｍｍに裁断したルテニウム膜１００ｎｍ付きウエハ片を５分間浸漬した。その後、ウエハ片を取り出して流水で水洗し、上記「３．３．１．研磨速度評価」と同様の方法によりルテニウム膜の厚さを測定した。そして、浸漬前後のルテニウム膜の厚さの変化からエッチング速度を下記式により算出した。
　ルテニウム膜のエッチング速度（ｎｍ／分）＝（エッチング前のルテニウム膜の厚さ（ｎｍ）－エッチング後のルテニウム膜の厚さ（ｎｍ））／エッチング時間（分） 3.3.2. Etching Rate Evaluation The chemical mechanical polishing composition prepared above was heated to 60° C., and a wafer piece with a ruthenium film of 100 nm cut into a size of 30 mm×10 mm was immersed in the composition for 5 minutes. After that, the wafer piece was taken out and washed with running water, and the thickness of the ruthenium film was measured by the same method as in "3.3.1. Polishing rate evaluation". Then, the etching rate was calculated from the change in the thickness of the ruthenium film before and after the immersion by the following formula.
Etching rate of ruthenium film (nm/min)=(thickness of ruthenium film before etching (nm)−thickness of ruthenium film after etching (nm))/etching time (min)
　ルテニウム膜のエッチング速度の評価基準は下記の通りである。ルテニウム膜のエッチング速度の評価結果を表１～表３に併せて示す。
（評価基準）
Ａ：エッチング速度が１．５ｎｍ／分未満である場合、非常に良好と判断した。
Ｂ：エッチング速度が１．５ｎｍ／分以上３ｎｍ／分未満である場合、実用に供することができるので良好と判断した。
Ｃ：エッチング速度が３ｎｍ／分以上である場合、エッチング速度が大きく実用困難であるため不良と判断した。 The evaluation criteria for the etching rate of the ruthenium film are as follows. Tables 1 to 3 also show the evaluation results of the etching rate of the ruthenium film.
(Evaluation criteria)
A: When the etching rate was less than 1.5 nm/min, it was judged to be very good.
B: When the etching rate was 1.5 nm/min or more and less than 3 nm/min, it was judged to be good because it could be put to practical use.
C: When the etching rate was 3 nm/min or more, the etching rate was so high that it was difficult to put into practical use, so it was judged to be defective.
　３．３．３．貯蔵安定性評価
　上記で調製した化学機械研磨用組成物を２０℃の恒温保管庫にて３日間または７日間保管した後、直径１２インチのルテニウム膜１００ｎｍ付きウエハを被研磨体として、上記「３．３．１．研磨速度評価」と同じ研磨条件で化学機械研磨試験を行った。そして、保管前後のルテニウム膜の研磨速度の変動率を下記式により算出した。
　変動率（％）＝｜（（「３．３．１．研磨速度評価」の項で算出された研磨速度）－（保管後の化学機械研磨用組成物を用いた場合の研磨速度））／（「３．３．１．研磨速度評価」の項で算出された研磨速度）×１００｜ 3.3.3. Storage stability evaluation After storing the chemical mechanical polishing composition prepared above in a constant temperature storage at 20 ° C. for 3 days or 7 days, a wafer having a diameter of 12 inches with a ruthenium film of 100 nm was used as a polishing object, and the above "3 A chemical mechanical polishing test was conducted under the same polishing conditions as in 3.1. Then, the fluctuation rate of the polishing rate of the ruthenium film before and after storage was calculated by the following formula.
Variation rate (%) = | ((polishing rate calculated in the section “3.3.1. Polishing rate evaluation”) - (polishing rate when using chemical mechanical polishing composition after storage))/ (Polishing speed calculated in the section “3.3.1. Polishing speed evaluation”)×100|
　変動率の評価基準は下記の通りである。化学機械研磨用組成物の貯蔵安定性の評価結果を表１～表３に併せて示す。
（評価基準）
Ａ：貯蔵後７日経過時の研磨速度の変動率が１０％未満である場合、非常に良好と判断した。
Ｂ：貯蔵後３日経過時の研磨速度の変動率が１０％未満であるが、貯蔵後７日経過時の研磨速度の変動率が１０％以上である場合、実用に供することができるので良好と判断した。
Ｃ：貯蔵後３日経過時の研磨速度の変動率が１０％以上である場合、実用困難であるため不良と判断した。 The evaluation criteria for the volatility are as follows. Tables 1 to 3 also show the storage stability evaluation results of the chemical mechanical polishing composition.
(Evaluation criteria)
A: A polishing rate variation of less than 10% after 7 days of storage was judged to be very good.
B: The rate of change in polishing rate after 3 days of storage is less than 10%, but when the rate of change in polishing rate after 7 days of storage is 10% or more, it can be put to practical use, which is favorable. I decided.
C: If the fluctuation rate of the polishing rate after 3 days of storage was 10% or more, it was judged to be unsatisfactory because it was difficult to put into practical use.
　３．４．評価結果
　表１～表３に、各実施例および各比較例で使用した化学機械研磨用組成物の組成ならびに各評価結果を示す。 3.4. Evaluation Results Tables 1 to 3 show the composition of the chemical mechanical polishing composition used in each example and each comparative example and each evaluation result.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　上表１～上表３中の各成分は、それぞれ下記の商品または試薬を用いた。
＜成分（Ａ）＞
・水分散体Ａ～Ｅ：上記「３．１．シリカ粒子水分散体の調製」の項で調製した水分散体Ａ～Ｅ
＜成分（Ｂ）＞
・Ｈ５ＩＯ６（過ヨウ素酸）：富士フイルム和光純薬社製、商品名「オルト過よう素酸」
・ＫＣｌＯ（次亜塩素酸カリウム）：関東化学社製、商品名「次亜塩素酸カリウム溶液」
・ＫＣｌＯ２（亜塩素酸カリウム）：Ａｎｇｅｎｅ社製、商品名「Ｐｏｔａｓｓｉｕｍ　Ｃｈｌｏｒｉｔｅ」
・ＮａＢｒＯ（次亜臭素酸ナトリウム）：関東化学社製、商品名「次亜臭素酸ナトリウム」
＜成分（Ｃ）＞
・過酸化水素：富士フイルム和光純薬社製、３０％水溶液
＜成分（Ｄ）＞
・Ｎ－（ホスホノメチル）イミノ二酢酸：シグマアルドリッチ社製、商品名「Ｎ－（ホスホノメチル）イミノ二酢酸　水和物」
・ヒドロキシエチルイミノ二酢酸：東京化成工業社製、商品名「Ｎ－（２－Ｈｙｄｒｏｘｙｅｔｈｙｌ）ｉｍｉｎｏｄｉａｃｅｔｉｃ　Ａｃｉｄ」
・Ｎ－（２－カルボキシエチル）イミノ二酢酸：東京化成工業社製、商品名「Ｎ－（２－Ｃａｒｂｏｘｙｅｔｈｙｌ）ｉｍｉｎｏｄｉａｃｅｔｉｃ　Ａｃｉｄ」
・ニトリロ三酢酸：東京化成工業社製、商品名「Ｎｉｔｒｉｌｏｔｒｉａｃｅｔｉｃ　Ａｃｉｄ」
・３，３’，３’’－ニトリロトリプロピオン酸：東京化成工業社製、商品名「３，３’，３’’－Ｎｉｔｒｉｌｏｐｒｏｐｉｏｎｉｃ　Ａｃｉｄ」
・エチレンジアミン四酢酸：東京化成工業社製、商品名「Ｅｔｈｙｌｅｎｅｄｉａｍｉｎｅｔｅｔｒａａｃｅｔｉｃ　Ａｃｉｄ」
・Ｌ－グルタミン酸二酢酸四ナトリウム：東京化成工業社製、商品名「Ｔｅｔｒａｓｏｄｉｕｍ　Ｎ，Ｎ－Ｂｉｓ（ｃａｒｂｏｘｙｍｅｔｈｙｌ）－Ｌ－ｇｌｕｔａｍａｔｅ　（ｃａ．　４０％　ｉｎ　Ｗａｔｅｒ）」
・グリシン－Ｎ，Ｎ－ビス（メチレンホスホン酸）：東京化成工業社製、商品名「Ｇｌｙｃｉｎｅ－Ｎ，Ｎ－ｂｉｓ（ｍｅｔｈｙｌｅｎｅｐｈｏｓｐｈｏｎｉｃ　Ａｃｉｄ）」
 
・グリコールエーテルジアミン四酢酸：東京化成工業社製、商品名「Ｅｔｈｙｌｅｎｅ　Ｇｌｙｃｏｌ　Ｂｉｓ（２－ａｍｉｎｏｅｔｈｙｌ　Ｅｔｈｅｒ）－Ｎ，Ｎ，Ｎ’，Ｎ’－ｔｅｔｒａａｃｅｔｉｃ　Ａｃｉｄ」
・ヒドロキシエチルエチレンジアミン三酢酸：東京化成工業社製、商品名「Ｎ－（２－Ｈｙｄｒｏｘｙｅｔｈｙｌ）ｅｔｈｙｌｅｎｅｄｉａｍｉｎｅ－Ｎ，Ｎ’，Ｎ’－ｔｒｉａｃｅｔｉｃ　Ａｃｉｄ」
＜その他の成分＞
・ＫＩＯ３（ヨウ素酸カリウム）：富士フイルム和光純薬社製、商品名「よう素酸カリウム」
・（ＮＨ４）２Ｓ２Ｏ８（ペルオキソ二硫酸アンモニウム）：富士フイルム和光純薬社製、商品名「ペルオキソ二硫酸アンモニウム」 The following products or reagents were used for each component in Tables 1 to 3 above.
<Component (A)>
Aqueous dispersions A to E: Aqueous dispersions A to E prepared in the above section "3.1. Preparation of silica particle aqueous dispersion"
<Component (B)>
・H 5 IO 6 (periodic acid): manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name “orthoperiodic acid”
・KClO (potassium hypochlorite): manufactured by Kanto Chemical Co., Ltd., trade name “potassium hypochlorite solution”
- KClO 2 (potassium chlorite): manufactured by Angene, trade name "Potassium Chlorite"
・ NaBrO (sodium hypobromite): manufactured by Kanto Chemical Co., Ltd., trade name “sodium hypobromite”
<Component (C)>
・ Hydrogen peroxide: Fujifilm Wako Pure Chemical Co., Ltd., 30% aqueous solution <Component (D)>
· N- (phosphonomethyl) iminodiacetic acid: manufactured by Sigma-Aldrich, trade name "N- (phosphonomethyl) iminodiacetic acid hydrate"
・ Hydroxyethyliminodiacetic acid: manufactured by Tokyo Chemical Industry Co., Ltd., trade name “N-(2-Hydroxyethyl) iminodiacetic Acid”
· N- (2-Carboxyethyl) iminodiacetic acid: manufactured by Tokyo Chemical Industry Co., Ltd., trade name "N- (2-Carboxyethyl) iminodiacetic Acid"
・ Nitrilotriacetic acid: manufactured by Tokyo Chemical Industry Co., Ltd., trade name "Nitrilotriacetic Acid"
3,3′,3″-nitrilotripropionic acid: manufactured by Tokyo Chemical Industry Co., Ltd., trade name “3,3′,3″-Nitrilopropionic Acid”
- Ethylenediaminetetraacetic acid: manufactured by Tokyo Chemical Industry Co., Ltd., trade name "Ethylenediaminetetraacetic Acid"
・ Tetrasodium L-glutamate diacetate: manufactured by Tokyo Chemical Industry Co., Ltd., trade name “Tetrasodium N,N-Bis (carboxymethyl)-L-glutamate (ca. 40% in Water)”
・ Glycine-N, N-bis (methylenephosphonic acid): manufactured by Tokyo Chemical Industry Co., Ltd., trade name “Glycine-N, N-bis (methylenephosphonic Acid)”

Glycol ether diamine tetraacetic acid: manufactured by Tokyo Chemical Industry Co., Ltd., trade name "Ethylene Glycol Bis (2-aminoethyl Ether)-N,N,N',N'-tetraacetic Acid"
Hydroxyethylethylenediamine triacetic acid: manufactured by Tokyo Chemical Industry Co., Ltd., trade name "N-(2-Hydroxyethyl)ethylenediamine-N,N',N'-triacetic Acid"
<Other ingredients>
・KIO 3 (potassium iodate): manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name “potassium iodate”
· (NH 4 ) 2 S 2 O 8 (ammonium peroxodisulfate): manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name “ammonium peroxodisulfate”
　実施例１～１８の化学機械研磨用組成物によれば、成分（Ｂ）がルテニウムを酸化してルテニウム膜の研磨速度を向上させることができると共に、ルテニウムと成分（Ｂ）に含まれる特定アニオン種との過剰な反応を防ぎ、ルテニウム膜の腐食を抑制できることがわかる。また、実施例１～１８の化学機械研磨用組成物に含有される成分（Ａ）のゼータ電位の絶対値が１０ｍＶ以上であることにより、貯蔵安定性が向上していることがわかる。 According to the chemical mechanical polishing compositions of Examples 1 to 18, the component (B) oxidizes ruthenium to improve the polishing rate of the ruthenium film, and ruthenium and the specific anions contained in the component (B) It can be seen that excessive reaction with seeds can be prevented and corrosion of the ruthenium film can be suppressed. Further, it can be seen that the absolute value of the zeta potential of the component (A) contained in the chemical mechanical polishing compositions of Examples 1 to 18 is 10 mV or more, thereby improving the storage stability.
　これに対し、特定アニオン種を含まない化合物を含有する比較例１～２の化学機械研磨用組成物によれば、ルテニウムを効果的に酸化させることができないためにルテニウム膜の研磨速度が小さくなることがわかる。ＭＡ／ＭＢが５０超の比較例３、５の化学機械研磨用組成物によれば、成分（Ｂ）の含有量に対する成分（Ａ）の含有量が多すぎるために、ルテニウムを効果的に酸化させることができず、ルテニウム膜の研磨速度が小さくなることがわかる。ＭＡ／ＭＢが０．２未満の比較例４の化学機械研磨用組成物によれば、成分（Ｂ）の含有量に対する成分（Ａ）の含有量が少なすぎるため過剰量の成分（Ｂ）によりルテニウム膜の腐食を誘発しており、成分（Ａ）のゼータ電位の絶対値が１０ｍＶ未満であるため貯蔵安定性が著しく損なわれていることがわかる。 On the other hand, according to the chemical mechanical polishing compositions of Comparative Examples 1 and 2, which contain compounds that do not contain the specific anion species, ruthenium cannot be effectively oxidized, and the ruthenium film polishing rate is low. I understand. According to the chemical mechanical polishing compositions of Comparative Examples 3 and 5, in which MA/MB exceeds 50, the content of component (A) is too large relative to the content of component (B), so ruthenium is effectively oxidized. It can be seen that the polishing rate of the ruthenium film is reduced. According to the chemical mechanical polishing composition of Comparative Example 4, in which the MA/MB ratio is less than 0.2, the content of component (A) relative to the content of component (B) is too small, resulting in an excessive amount of component (B). Corrosion of the ruthenium film is induced, and since the absolute value of the zeta potential of the component (A) is less than 10 mV, it can be seen that the storage stability is significantly impaired.
　本発明は、前述した実施形態に限定されるものではなく、種々の変形が可能である。例えば、本発明は、実施形態で説明した構成と実質的に同一の構成（例えば、機能、方法および結果が同一の構成、あるいは目的および効果が同一の構成）を含む。また、本発明は、実施形態で説明した構成の本質的でない部分を置き換えた構成を含む。また、本発明は、実施形態で説明した構成と同一の作用効果を奏する構成または同一の目的を達成することができる構成を含む。また、本発明は、実施形態で説明した構成に公知技術を付加した構成を含む。 The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same function, method, and result, or configurations that have the same purpose and effect). Moreover, the present invention includes configurations in which non-essential portions of the configurations described in the embodiments are replaced. Moreover, the present invention includes a configuration that achieves the same effects as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the present invention includes configurations obtained by adding known techniques to the configurations described in the embodiments.
１０…基体、１２…酸化シリコン膜、１４…配線用溝、１６…ルテニウム含有膜、１８…銅膜、４２…スラリー供給ノズル、４４…スラリー（化学機械研磨用組成物）、４６…研磨用パッド、４８…ターンテーブル、５０…半導体基板、５２…キャリアーヘッド、５４…水供給ノズル、５６…ドレッサー、１００…被処理体、２００…研磨装置 DESCRIPTION OF SYMBOLS 10... Substrate, 12... Silicon oxide film, 14... Wiring groove, 16... Ruthenium-containing film, 18... Copper film, 42... Slurry supply nozzle, 44... Slurry (chemical mechanical polishing composition), 46... Polishing pad , 48... Turntable, 50... Semiconductor substrate, 52... Carrier head, 54... Water supply nozzle, 56... Dresser, 100... Object to be processed, 200... Polishing apparatus

Claims (6)

  1. 　砥粒（Ａ）と、
    　過ヨウ素酸イオン（ＩＯ４ －）、次亜塩素酸イオン（ＣｌＯ－）、亜塩素酸イオン（ＣｌＯ２ －）および次亜臭素酸イオン（ＢｒＯ－）からなる群より選択される少なくとも１種のアニオンを含む酸またはその塩（Ｂ）と、
    　液状媒体と、
    を含有する化学機械研磨用組成物であって、
    　前記砥粒（Ａ）の含有量をＭＡ（質量％）、前記酸またはその塩（Ｂ）の含有量をＭＢ（質量％）とした場合、ＭＡ／ＭＢ＝０．２～５０であり、
    　前記化学機械研磨用組成物中の前記砥粒（Ａ）のゼータ電位の絶対値が１０ｍＶ以上である、化学機械研磨用組成物。     Abrasive grains (A);
    At least one selected from the group consisting of periodate ions (IO 4 − ), hypochlorite ions (ClO − ), chlorite ions (ClO 2 − ) and hypobromite ions (BrO − ) an acid containing an anion or a salt thereof (B);
    a liquid medium;
    A chemical mechanical polishing composition containing
    When the content of the abrasive grains (A) is MA (% by mass) and the content of the acid or salt thereof (B) is MB (% by mass), MA/MB = 0.2 to 50,
    The chemical mechanical polishing composition, wherein the absolute value of the zeta potential of the abrasive grains (A) in the chemical mechanical polishing composition is 10 mV or more.
  2. 　前記ＭＡ（質量％）が０．０１～１０質量％である、請求項１に記載の化学機械研磨用組成物。 The chemical mechanical polishing composition according to claim 1, wherein the MA (% by mass) is 0.01 to 10% by mass.
  3. 　前記ＭＢ（質量％）が０．０１～１０質量％である、請求項１または請求項２に記載の化学機械研磨用組成物。 The chemical mechanical polishing composition according to claim 1 or 2, wherein the MB (% by mass) is 0.01 to 10% by mass.
  4. 　ｐＨが６以上１２以下である、請求項１ないし請求項３のいずれか一項に記載の化学機械研磨用組成物。 The chemical mechanical polishing composition according to any one of claims 1 to 3, which has a pH of 6 or more and 12 or less.
  5. 　請求項１ないし請求項４のいずれか一項に記載の化学機械研磨用組成物を用いて半導体基板を研磨する工程を含む、研磨方法。 A polishing method, comprising the step of polishing a semiconductor substrate using the chemical mechanical polishing composition according to any one of claims 1 to 4.
  6. 　前記半導体基板が、ルテニウムおよびルテニウム合金からなる群より選択される少なくとも１種により構成される部位を備える、請求項５に記載の研磨方法。 The polishing method according to claim 5, wherein the semiconductor substrate has a portion composed of at least one selected from the group consisting of ruthenium and ruthenium alloys.
PCT/JP2022/029477 2021-08-24 2022-08-01 Composition for chemical mechanical polishing and polishing method WO2023026779A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013137192A1 (en) * 2012-03-16 2013-09-19 株式会社フジミインコーポレーテッド Polishing composition
JP2016032109A (en) * 2014-07-28 2016-03-07 ローム アンド ハース エレクトロニック マテリアルズ シーエムピー ホウルディングス インコーポレイテッド Method for chemical and mechanical polishing of substrate including ruthenium and copper
JP2020010029A (en) * 2018-07-03 2020-01-16 ローム アンド ハース エレクトロニック マテリアルズ シーエムピー ホウルディングス インコーポレイテッド Neutral to alkaline chemical mechanical polishing compositions and methods for tungsten
JP2020096190A (en) * 2015-03-04 2020-06-18 日立化成株式会社 Polishing liquid for CMP and polishing method using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013137192A1 (en) * 2012-03-16 2013-09-19 株式会社フジミインコーポレーテッド Polishing composition
JP2016032109A (en) * 2014-07-28 2016-03-07 ローム アンド ハース エレクトロニック マテリアルズ シーエムピー ホウルディングス インコーポレイテッド Method for chemical and mechanical polishing of substrate including ruthenium and copper
JP2020096190A (en) * 2015-03-04 2020-06-18 日立化成株式会社 Polishing liquid for CMP and polishing method using the same
JP2020010029A (en) * 2018-07-03 2020-01-16 ローム アンド ハース エレクトロニック マテリアルズ シーエムピー ホウルディングス インコーポレイテッド Neutral to alkaline chemical mechanical polishing compositions and methods for tungsten

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