WO2016098817A1 - Cmp polishing liquid and polishing method using same - Google Patents

Cmp polishing liquid and polishing method using same Download PDF

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Publication number
WO2016098817A1
WO2016098817A1 PCT/JP2015/085246 JP2015085246W WO2016098817A1 WO 2016098817 A1 WO2016098817 A1 WO 2016098817A1 JP 2015085246 W JP2015085246 W JP 2015085246W WO 2016098817 A1 WO2016098817 A1 WO 2016098817A1
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Prior art keywords
polishing
cobalt
metal
cmp
barrier metal
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PCT/JP2015/085246
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French (fr)
Japanese (ja)
Inventor
雅弘 坂下
祐哉 大塚
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日立化成株式会社
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Publication of WO2016098817A1 publication Critical patent/WO2016098817A1/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
    • 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 polishing slurry for CMP and a polishing method using the same.
  • CMP Chemical Mechanical Polishing
  • a conductive material portion is deposited on an insulating material portion having a concave portion (for example, a groove portion) and a convex portion (for example, a raised portion) formed in advance on the surface, and the conductive material is embedded in the concave portion.
  • the conductive material deposited on the convex portion is removed by CMP to form a buried wiring.
  • a polishing pad is attached on a circular polishing platen (platen), and the surface of the polishing pad is immersed in a CMP polishing liquid.
  • a predetermined pressure hereinafter referred to as “polishing pressure”
  • polishing pressure a predetermined pressure
  • a barrier metal portion 2 is usually between the insulating material portion 1 having irregularities and the conductive material portion 3 provided on the insulating material portion 1. It is formed.
  • the purpose of providing the barrier metal portion 2 is to prevent the conductive material from diffusing into the insulating material portion 1 and to improve the adhesion between the insulating material portion 1 and the conductive material portion 3.
  • the barrier metal portion 2 is formed of a barrier metal (hereinafter sometimes referred to as “barrier metal”). Since the barrier metal is a conductor, it is necessary to remove the barrier metal in the same manner as the conductive material except for the concave portion (that is, the wiring portion) in which the conductive material is embedded.
  • removals include a “first polishing step” in which the conductive material portion 3 is polished from the state shown in FIG. 3A to the state shown in FIG. 3B, and the state shown in FIG.
  • a two-stage polishing method in which polishing is performed with different polishing liquids for CMP is applied to the “second polishing step” in which the barrier metal portion 2 is polished from the state shown in FIG. 3C to the state shown in FIG. Yes.
  • the thickness of each part tends to become thinner.
  • the barrier metal part 2 is reduced in thickness, thereby reducing the effect of preventing the diffusion of the conductive substance.
  • the adhesion between the barrier metal part 2 and the conductive substance part 3 tends to decrease.
  • the wiring width becomes narrower, it becomes difficult to embed the conductive material in the recess (that is, the embedding property is lowered), and voids called voids are easily generated in the conductive material part 3. Challenges arise.
  • cobalt Co
  • diffusion of the conductive material can be suppressed.
  • cobalt has a high affinity with a conductive material (for example, a copper-based metal such as copper or a copper alloy)
  • the embedding property of the conductive material is improved.
  • cobalt can supplement the adhesion between the insulating material and the conductive material.
  • cobalt is more corrosive than metals such as copper-based metals that have been used as conductive materials. Cobalt is excessively etched or slits are formed in the wiring pattern. As a result, there is a concern that metal ions may diffuse into the insulating material portion without fulfilling the function as the barrier metal portion. When metal ions diffuse into the insulating material portion, there is a high possibility that a short circuit occurs in the semiconductor device. On the other hand, in order to prevent this, if a metal anticorrosive having a strong anticorrosive action is added to the CMP polishing liquid or the amount of the metal anticorrosive added is increased, the polishing rate of cobalt is lowered.
  • the present invention is intended to solve the above-described problems, and provides a polishing slurry for CMP that can suppress the etching rate of cobalt while maintaining a good polishing rate of cobalt, and a polishing slurry for CMP.
  • An object is to provide a polishing method used.
  • one embodiment of the present invention is a polishing slurry for CMP used for polishing a surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt.
  • a polishing slurry for CMP which contains water and has a pH of 4.0 or less, and both of the two types of metal corrosion inhibitors are azoles (excluding salts of inorganic acids).
  • the etching rate of cobalt (eg, cobalt layer) can be suppressed while maintaining a good polishing rate of cobalt (eg, cobalt layer).
  • cobalt can be protected by effectively suppressing the etching rate of cobalt.
  • the etching rate of cobalt can be suppressed to 10 nm / min or less.
  • the polishing rate of cobalt and a metal material (a material constituting a metal-containing portion, excluding cobalt) is excellent.
  • One embodiment of the CMP polishing liquid may further contain a water-soluble polymer. This makes it possible to easily suppress galvanic corrosion of the cobalt-containing portion, protect the surface to be polished, reduce the occurrence of defects, and the like.
  • the abrasive particles may include at least one selected from the group consisting of silica particles, alumina particles, ceria particles, titania particles, zirconia particles, germania particles, and modified products thereof. Good. Thereby, there exists a tendency for the grinding
  • an embodiment of the polishing slurry for CMP further contains a metal oxidizing agent.
  • rate of a metal material can be improved more.
  • One embodiment of the polishing slurry for CMP may further contain an organic solvent.
  • At least a part of the cobalt-containing portion of the surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt, using the CMP polishing liquid. It is related with the grinding
  • an insulating material portion having a concave portion and a convex portion on a surface thereof, a barrier metal portion covering the insulating material portion along the concave portion and the convex portion, and filling the concave portion are described above.
  • the material part has a metal-containing part containing a metal other than cobalt.
  • the insulating material portion may be at least one selected from the group consisting of a silicon-based insulator and an organic polymer-based insulator.
  • the conductive material portion may contain copper as a main component.
  • the barrier metal part includes the cobalt-containing part and at least one selected from the group consisting of a tantalum-containing part, a titanium-containing part, a tungsten-containing part, and a ruthenium-containing part. Also good.
  • the embodiment of the present invention it is possible to provide a CMP polishing liquid capable of suppressing the cobalt etching rate while maintaining a good cobalt polishing rate, and a polishing method using the CMP polishing liquid.
  • cobalt can be protected by effectively suppressing the etching rate of cobalt.
  • the etching rate of cobalt can be suppressed to 10 nm / min or less.
  • the “polishing rate” means a rate at which the material A to be CMP is removed by polishing (for example, a reduction amount of the thickness of the material A per time. Removable Rate).
  • Process is not only an independent process, but even if it cannot be clearly distinguished from other processes, it cannot be clearly distinguished from other processes as long as the operations specified in the “process” are performed. A process is also included.
  • the numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
  • the content of each component in the CMP polishing liquid is the sum of the plurality of substances present in the CMP polishing liquid, unless otherwise specified, when a plurality of substances corresponding to each component are present in the CMP polishing liquid. Means quantity.
  • the CMP polishing liquid according to this embodiment is a CMP polishing liquid used for polishing a surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt.
  • the polishing slurry for CMP according to this embodiment contains abrasive particles (hereinafter sometimes referred to as “abrasive grains”), two types of metal anticorrosives, and water, and has a pH of 4.0 or less.
  • the polishing liquid for CMP contains abrasive grains.
  • the inclusion of abrasive grains tends to improve the polishing rate of a metal material (for example, a metal material of a metal-containing portion provided in the vicinity of the cobalt-containing portion).
  • An abrasive grain can be used individually by 1 type or in mixture of 2 or more types.
  • inorganic abrasive particles such as silica particles, alumina particles, ceria particles, titania particles, zirconia particles, germania particles and silicon carbide particles; organic abrasive particles such as polystyrene particles, polyacrylic acid particles and polyvinyl chloride particles;
  • the abrasive grains are preferably at least one selected from the group consisting of silica particles, alumina particles, ceria particles, titania particles, zirconia particles, germania particles, and modified products thereof.
  • At least selected from the group consisting of silica particles and alumina particles from the viewpoint of good dispersion stability in the CMP polishing liquid and a small number of polishing scratches (sometimes referred to as “scratches”) generated by CMP.
  • One type is preferable, at least one selected from the group consisting of colloidal silica and colloidal alumina is more preferable, and colloidal silica is more preferable.
  • the content of the abrasive grains is preferably 1.0% by mass or more, more preferably 1.2% by mass or more, and still more preferably from the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt. It is 1.5% by mass or more, particularly preferably 2.0% by mass or more.
  • the content of the abrasive grains is preferably 5.0% by mass or less, more preferably 5.0% by mass or less, based on the total mass of the polishing slurry for CMP, from the viewpoint of maintaining good dispersion stability of the abrasive grains and suppressing the occurrence of polishing flaws. Is 4.5% by mass or less, more preferably 4.0% by mass or less, and particularly preferably 3.0% by mass or less.
  • the average particle size (average secondary particle size) of the abrasive grains is preferably 40 nm or more, more preferably 45 nm or more, still more preferably 50 nm or more, and particularly preferably 60 nm or more, from the viewpoint of obtaining a better polishing rate of cobalt. is there.
  • the average grain size of the abrasive grains is preferably 90 nm or less, more preferably 85 nm or less, still more preferably 80 nm or less, and particularly preferably 70 nm or less from the viewpoint of suppressing polishing flaws.
  • the particle diameter of the abrasive grains can be measured with a light diffraction scattering type particle size distribution meter (for example, “COULTER N4SD” manufactured by COULTER Electronics) using a water dispersion obtained by appropriately diluting a CMP polishing liquid with water as a sample.
  • a light diffraction / scattering particle size distribution meter for example, “COULTER N4SD” manufactured by COULTER Electronics
  • the measurement conditions of a light diffraction / scattering particle size distribution meter are: measurement temperature 20 ° C., solvent refractive index 1.333 (corresponding to the refractive index of water), particle refractive index Unknown (setting), solvent viscosity 1.005 mPa ⁇ s ( Equivalent to the viscosity of water), Run Time 200 sec, and laser incident angle 90 °.
  • the CMP polishing liquid contains two types of metal anticorrosives. By containing two types of metal anticorrosive agents, the etching rate of cobalt can be suppressed to 10 nm / min or less while maintaining a good polishing rate of cobalt.
  • Two types of metal anticorrosives are selected from azoles (compounds having an azole skeleton, excluding inorganic salts of azoles) from the viewpoint of suppressing etching of the cobalt-containing portion while maintaining a good polishing rate of cobalt.
  • the CMP polishing liquid may contain three or more types of azoles.
  • the CMP polishing liquid may contain a metal anticorrosive other than azoles.
  • the polishing liquid for CMP contains at least two kinds of azoles that do not correspond to inorganic acid salts of azoles.
  • azoles include pyrazoles (compounds having a pyrazole skeleton), imidazoles (compounds having an imidazole skeleton), thiazoles (compounds having a thiazole skeleton, excluding compounds corresponding to benzothiazoles), Benzothiazoles (compounds having a benzothiazole skeleton), tetrazoles (compounds having a tetrazole skeleton), triazoles (compounds having a triazole skeleton, excluding compounds corresponding to benzotriazoles), and benzotriazoles (benzotriazole skeletons) At least one selected from the group consisting of:
  • Pyrazoles include pyrazole, 1H-pyrazole-3,5-dicarboxylic acid, 1-allyl-3,5-dimethylpyrazole, 3,5-di (2-pyridyl) pyrazole, 3,5-diisopropylpyrazole, 3, 5-dimethyl-1-hydroxymethylpyrazole, 3,5-dimethyl-1-phenylpyrazole, 3,5-dimethylpyrazole, 3-amino-5-hydroxypyrazole, 4-methylpyrazole, N-methylpyrazole, 3-amino Examples include pyrazole and 3-amino-5-methylpyrazole.
  • imidazoles examples include 1,1′-carbonylbis-1H-imidazole, 1,1′-oxalyldiimidazole, 1,2,4,5-tetramethylimidazole, 1,2-dimethyl-5-nitroimidazole, 1,2-dimethylimidazole, 1- (3-aminopropyl) imidazole, 1-butylimidazole, 1-ethylimidazole, 1-methylimidazole, 1H-1,2,3-triazolo [4,5-b] pyridine, etc. Can be mentioned.
  • thiazoles examples include 2,4-dimethylthiazole.
  • benzothiazoles examples include 2-mercaptobenzothiazole.
  • tetrazoles examples include tetrazole, 5-methyltetrazole, 5-aminotetrazole, 5-amino-1-hydroxytetrazole, 1,5-pentamethylenetetrazole, 1- (2-dimethylaminoethyl) -5-mercaptotetrazole and the like.
  • triazoles examples include 1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole and the like.
  • Benzotriazoles include benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole 4-carboxybenzotriazole, 5-methylbenzotriazole, 1- (formamidomethyl) -1H-benzotriazole and the like.
  • the metal anticorrosive agent is selected from the group consisting of pyrazoles, imidazoles, thiazoles, benzothiazoles and tetrazoles from the viewpoint of further effectively suppressing the etching of the cobalt-containing portion while maintaining a good polishing rate of cobalt. At least one kind is preferred, and benzotriazoles are more preferred.
  • the content (total content) of the metal anticorrosive is preferably 0.001% by mass or more, more preferably 0.01% in the total mass of the polishing slurry for CMP, from the viewpoint of further suppressing galvanic corrosion of the cobalt-containing part. % By mass or more, more preferably 0.02% by mass or more, particularly preferably 0.05% by mass or more, very preferably 0.1% by mass or more, and very preferably 0.2% by mass or more.
  • the content of the metal anticorrosive is preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 1% in the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt. It is not more than mass%, particularly preferably not more than 0.5 mass%.
  • the CMP polishing liquid may further contain organic acids.
  • Organic acids have the effect of further improving the polishing rate of cobalt and metal materials.
  • the organic acids may be at least one selected from the group consisting of organic acids, organic acid salts, organic acid anhydrides, and organic acid esters.
  • phthalic acids are preferable from the viewpoint of further suppressing corrosion of the cobalt-containing part. By using phthalic acids, a better polishing rate of cobalt can be obtained, and corrosion can be further suppressed.
  • the phthalic acids may be at least one selected from the group consisting of phthalic acid, phthalic acid salts, phthalic anhydrides and phthalic acid esters.
  • Organic acids (phthalic acid etc.) may have a substituent and may not have a substituent.
  • the organic acids can be used singly or in combination of two or more.
  • phthalic acids include: phthalic acid; alkylphthalic acid such as 3-methylphthalic acid and 4-methylphthalic acid; aminophthalic acid such as 3-aminophthalic acid and 4-aminophthalic acid; nitrophthalic acid such as 3-nitrophthalic acid and 4-nitrophthalic acid
  • phthalic acid having a methyl group as a substituent is preferable, at least one selected from the group consisting of 3-methylphthalic acid and 4-methylphthalic acid is more preferable, and 4-methylphthalic acid is still more preferable.
  • the salt include salts with alkali metals such as sodium and potassium; salts with alkaline earth metals such as magnesium and calcium; ammonium salts and the like.
  • the content of the organic acids is from the viewpoint of further suppressing the galvanic corrosion of the cobalt-containing part, preferably 0.001% by mass or more in the total mass of the CMP polishing liquid. More preferably, it is 0.01 mass% or more, More preferably, it is 0.02 mass% or more.
  • the content of the organic acid is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 1% by mass in the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt. % Or less.
  • the CMP polishing liquid preferably contains a metal oxidizing agent.
  • the metal oxidizing agent is not particularly limited, and examples thereof include hydrogen peroxide, peroxosulfate, nitric acid, potassium periodate, hypochlorous acid, and ozone. From the viewpoint of further improving the polishing rate of cobalt and metal materials, hydrogen peroxide is particularly preferable.
  • a metal oxidizing agent can be used individually by 1 type or in mixture of 2 or more types.
  • the content of the metal oxidizer is 0.01% by mass in the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt and the metal material.
  • the above is preferable, 0.02% by mass or more is preferable, and 0.05% by mass or more is more preferable.
  • the content of the metal oxidant is preferably 30% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, and particularly preferably 5% by mass or less, from the viewpoint of preventing roughness of the surface to be polished. 1 mass% or less is very preferable, 0.5 mass% or less is very preferable, and 0.1 mass% or less is still more preferable.
  • the CMP polishing liquid may further contain an organic solvent.
  • an organic solvent By including the organic solvent, the wettability of the polishing slurry for CMP with respect to the metal-containing part (for example, the metal-containing part provided in the vicinity of the cobalt-containing part) can be improved.
  • an organic solvent The solvent which can be mixed with water is preferable, and the solvent which melt
  • An organic solvent can be used individually by 1 type or in mixture of 2 or more types.
  • Organic solvents include carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate; lactones such as butyl lactone and propyl lactone; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene Glycols such as glycol and tripropylene glycol; derivatives of glycols; ethers such as tetrahydrofuran, dioxane, dimethoxyethane, polyethylene oxide, ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (glycols) Excluding derivatives); methanol, ethanol Alcohols (monoalcohols) such as propanol, n-butanol, n-pentanol, n-hexanol, isopropanol, 3-methoxy-3-methyl
  • the organic solvent may be a derivative of glycols.
  • glycol derivatives include ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether.
  • the organic solvent is preferably at least one selected from the group consisting of glycols, glycol derivatives, alcohols and carbonates, and more preferably alcohols.
  • the content of the organic solvent is 0.1% by mass or more in the total mass of the CMP polishing liquid from the viewpoint of obtaining good wettability with respect to the metal-containing portion. It is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and extremely preferably 1.2% by mass or more. Further, the content of the organic solvent is preferably 95% by mass or less and more preferably 50% by mass or less in the total mass of the polishing slurry for CMP from the viewpoint of preventing the possibility of ignition and safely implementing the manufacturing process. 10 mass% or less is further more preferable, 5 mass% or less is especially preferable, 3 mass% or less is very preferable, 2 mass% or less is very preferable, and 1.5 mass% or less is much more preferable.
  • the CMP polishing liquid may further contain a water-soluble polymer.
  • a water-soluble polymer By containing the water-soluble polymer, it is possible to easily suppress the galvanic corrosion of the cobalt-containing portion, protect the surface to be polished, reduce the occurrence of defects, and the like.
  • the water-soluble polymer is preferably a polymer that dissolves 0.1 g or more in 100 g of water at 25 ° C.
  • a water-soluble polymer can be used individually by 1 type or in mixture of 2 or more types.
  • the water-soluble polymer is preferably a water-soluble polymer having at least one selected from the group consisting of a carboxylic acid group and a carboxylic acid group.
  • the polycarboxylic acid and its salt means “polycarboxylic acid”). More preferably, it means “polymer in which part or all of the carboxylic acid groups of the acid are substituted with carboxylic acid groups”.
  • Examples of the carboxylate group include an ammonium carboxylate group and a sodium carboxylate group.
  • Polycarboxylic acids and salts thereof include homopolymers of monomers having a carboxylic acid group, such as acrylic acid, methacrylic acid, and maleic acid; some or all of the carboxylic acid groups of the homopolymer are substituted with carboxylic acid groups
  • Specific examples include polyacrylic acid; polyacrylic acid ammonium salt (meaning “a polymer in which part or all of the carboxylic acid group of polyacrylic acid is substituted with a carboxylic acid ammonium base”) and the like.
  • water-soluble polymers include polyaspartic acid, polyglutamic acid, polylysine, polymalic acid, polyamic acid, polyamic acid ammonium salt, polyamic acid sodium salt, polyglyoxylic acid and other polycarboxylic acids and salts thereof; alginic acid And polysaccharides such as pectinic acid, carboxymethylcellulose, agar, curdlan and pullulan; and vinyl polymers such as polyvinyl alcohol, polyvinylpyrrolidone and polyacrolein.
  • polycarboxylic acid or a salt thereof pectic acid; agar; polymalic acid; polyacrylamide; polyvinyl alcohol; polyvinyl pyrrolidone; an ester or ammonium salt thereof is preferable, and a polyacrylic acid ammonium salt is more preferable.
  • the weight average molecular weight of the water-soluble polymer is preferably 500 or more, more preferably 1,000 or more, still more preferably 2,000 or more, and particularly preferably 5,000 or more, from the viewpoint of obtaining a higher polishing rate of cobalt. . Further, the weight average molecular weight of the water-soluble polymer is preferably 1,000,000 or less, more preferably 500,000 or less, still more preferably 200,000 or less, and particularly preferably 100,000 or less, from the viewpoint of excellent solubility. Very preferably 20,000 or less.
  • weight average molecular weight a value measured by gel permeation chromatography (GPC) based on the following method and converted to standard polyacrylic acid can be used.
  • the content of the water-soluble polymer is preferably 0.001% by mass in the total mass of the polishing slurry for CMP from the viewpoint of further suppressing galvanic corrosion of the cobalt-containing portion. As mentioned above, More preferably, it is 0.005 mass% or more, More preferably, it is 0.01 mass% or more. Further, the content of the water-soluble polymer is preferably 10% by mass or less, more preferably 5.0% by mass or less, and still more preferably from the total mass of the polishing slurry for CMP, from the viewpoint of obtaining a better polishing rate of cobalt. Is 1.0% by mass or less, particularly preferably 0.5% by mass or less, very preferably 0.1% by mass or less, and very preferably 0.05% by mass or less.
  • the CMP polishing liquid contains water.
  • the water is not particularly limited, but pure water can be preferably used. There is no particular limitation on the water content as long as water is blended as the remainder of the other components.
  • the pH of the polishing liquid for CMP is 4.0 or less. When pH is 4.0 or less, it is excellent in the polishing rate of cobalt and a metal material.
  • the pH of the polishing slurry for CMP is preferably 3.8 or less, more preferably 3.6 or less, and even more preferably 3.5 or less.
  • the pH of the polishing slurry for CMP is preferably 2.0 or more from the viewpoint of further suppressing galvanic corrosion of the cobalt-containing part and the metal-containing part, and from the viewpoint of eliminating difficulty in handling due to strong acidity. 0.5 or more is more preferable, 2.8 or more is further preferable, and 3.0 or more is particularly preferable.
  • the pH of the CMP polishing liquid can be adjusted by the amount of acid component added.
  • the pH of the CMP polishing liquid can also be adjusted by adding an alkaline component such as ammonia, sodium hydroxide, tetramethylammonium hydroxide (TMAH), or the like.
  • an alkaline component such as ammonia, sodium hydroxide, tetramethylammonium hydroxide (TMAH), or the like.
  • the pH of the polishing slurry for CMP can be measured with a pH meter (for example, “PHL-40” manufactured by Electrochemical Instrument Co., Ltd.). After three-point calibration using standard buffer (phthalate pH buffer, pH: 4.01, neutral phosphate pH buffer, pH: 6.86, borate pH buffer, pH: 9.18) The value after the electrode is put into the CMP polishing liquid and stabilized for 3 minutes or longer can be measured as the pH of the CMP polishing liquid. At this time, the temperature of the standard buffer solution and the polishing solution for CMP are both 25 ° C.
  • the CMP polishing liquid can be applied to the formation of a wiring pattern in a semiconductor device, for example.
  • a metal containing part the electroconductive substance part mentioned later is mentioned, for example.
  • the surface to be polished may include an insulating material portion described later. The materials constituting the cobalt-containing part and the metal-containing part will be described later.
  • the polishing method according to the present embodiment uses a polishing liquid for CMP according to the present embodiment, and includes a cobalt-containing part (a part containing cobalt) and a metal-containing part containing a metal other than cobalt (a part not containing cobalt). ) At least a part of the cobalt-containing portion of the surface to be polished.
  • the polishing method according to the present embodiment is preferably a polishing method in which an excess portion of the cobalt-containing portion in the substrate having the cobalt-containing portion and the metal-containing portion formed on at least one surface is polished and removed.
  • the polishing method according to the present embodiment is for the CMP according to the present embodiment between the surface of the substrate on which the cobalt-containing portion and the metal-containing portion are formed and the polishing pad on the polishing surface plate.
  • a polishing method in which at least a part of the cobalt-containing portion is polished and removed by relatively moving the substrate and the polishing surface plate while the substrate is pressed against the polishing pad while supplying the polishing liquid may be used. .
  • the polishing method according to this embodiment can be applied to a series of steps for forming a wiring layer in a semiconductor device.
  • the polishing method according to the present embodiment includes, for example, an insulating material portion having a concave portion and a convex portion on the surface, a barrier metal portion that covers the insulating material portion along the concave portion and the convex portion, and the concave portion.
  • substrate may be the aspect in which the said barrier metal part has a cobalt containing part, and the said electroconductive substance part has a metal containing part containing metals other than cobalt.
  • the substrate shown in FIG. 1 has a cobalt-containing portion 2a as a barrier metal portion and a metal-containing portion 3a as a conductive material portion.
  • a substrate 10 before polishing is formed on a silicon substrate (not shown) along an insulating material part 1 having a predetermined pattern of concave parts and irregularities on the surface of the insulating material part 1.
  • a cobalt-containing part 2a that covers the insulating material part 1 and a metal-containing part 3a formed on the cobalt-containing part 2a.
  • the substrate shown in FIG. 2 has a cobalt-containing portion 2a and a barrier metal portion 2b as the barrier metal portion 2, and a metal-containing portion 3a as the conductive material portion.
  • the substrate 110 before polishing is formed on a silicon substrate (not shown) along an insulating material portion 1 having a predetermined pattern of concave portions and irregularities on the surface of the insulating material portion 1.
  • Examples of the material for forming the insulating material portion 1 include a silicon-based insulator and an organic polymer-based insulator.
  • silicon-based insulators include silicon dioxide, fluorosilicate glass, organosilicate glass (for example, organosilicate obtained from trimethylsilane, dimethoxydimethylsilane, etc.), silicon oxynitride, silsesquioxane hydride, etc. Examples thereof include silica-based insulators; silicon carbide; silicon nitride.
  • Examples of the organic polymer insulator include wholly aromatic low dielectric constant insulators. Among these, silicon dioxide is particularly preferable.
  • the insulating material portion 1 can be formed by, for example, a CVD (chemical vapor deposition) method, a spin coating method, a dip coating method, a spray method, or the like.
  • Specific examples of the insulating material part 1 include an interlayer insulating film in an LSI manufacturing process (particularly, a multilayer wiring forming process).
  • the barrier metal portion is formed to prevent the conductive material from diffusing into the insulating material portion 1 and to improve the adhesion between the insulating material portion 1 and the conductive material portion.
  • Examples of the material used for forming the cobalt-containing portion 2a include cobalt compounds such as cobalt, a cobalt alloy, a cobalt oxide, and a cobalt alloy oxide.
  • barrier metal used to form the barrier metal portion 2b examples include tantalum compounds such as tantalum, tantalum nitride, and tantalum alloys; titanium compounds such as titanium, titanium nitride, and titanium alloys; tungsten compounds such as tungsten, tungsten nitride, and tungsten alloys; Examples include ruthenium compounds such as ruthenium, ruthenium nitride, and ruthenium alloys.
  • the barrier metal part 2b may have, for example, a single layer structure made of one of these, or a laminated structure made of two or more kinds.
  • the barrier metal part 2b can have at least one selected from the group consisting of a tantalum-containing part, a titanium-containing part, a tungsten-containing part, and a ruthenium-containing part.
  • the barrier metal part can be formed by, for example, vapor deposition, CVD (chemical vapor deposition), sputtering, or the like.
  • the metal-containing portion 3a as the conductive material portion includes a copper-based metal such as copper, a copper alloy, a copper oxide, or a copper alloy oxide; a tungsten or a tungsten alloy as a main component.
  • Metals to be used Noble metals such as silver and gold can be used. Of these, metals mainly composed of copper, such as copper, copper alloys, copper oxides, and copper alloy oxides, are preferred.
  • a metal mainly composed of copper refers to a metal having the largest copper content (mass).
  • the metal containing part 3a is formed by, for example, a known sputtering method, plating method or the like.
  • the thickness of the insulating material part 1 is preferably about 0.01 to 2.0 ⁇ m.
  • the thickness of the cobalt-containing portion 2a is preferably about 0.01 to 2.5 ⁇ m.
  • the thickness of the barrier metal part 2b is preferably about 0.01 to 2.5 ⁇ m.
  • the thickness of the metal-containing portion 3a is preferably about 0.01 to 2.5 ⁇ m.
  • the metal-containing portion 3a (that is, the conductive material portion) is polished.
  • the material part is polished by CMP.
  • the polishing slurry for CMP for a conductive material having a sufficiently high polishing rate ratio of the conductive material portion / cobalt-containing portion 2a for example, the polishing slurry for CMP described in Japanese Patent No. 3337464 can be used.
  • a part of the cobalt-containing portion 2a on the convex portion may be polished together with the conductive substance portion.
  • the cobalt-containing portion 2a exposed by the first polishing step from the state shown in FIG. 1B to the state shown in FIG. 1C is used as the polishing slurry for CMP according to this embodiment. Is used to remove excess cobalt-containing parts.
  • the state shown in FIG. 2 when the barrier metal part 2 has a cobalt-containing part 2a and a barrier metal part 2b, in the second polishing step, the state shown in FIG.
  • the cobalt-containing part 2a and the barrier metal part 2b are polished to the state shown in (c), and the extra cobalt-containing part and the extra barrier metal part 2b are removed.
  • the cobalt-containing portion 2a is polished with the CMP polishing liquid according to the present embodiment.
  • the polishing is terminated, and separately, with the CMP polishing liquid for polishing the barrier metal portion 2b.
  • the barrier metal part 2b may be polished. Further, as a series of steps, the cobalt-containing portion 2a and the barrier metal portion 2b may be polished with the CMP polishing liquid according to the present embodiment.
  • the insulating material part 1 under the protruding barrier metal part (cobalt-containing part 2a or cobalt-containing part 2a and barrier metal part 2b) is completely exposed, leaving a conductive substance part that becomes a wiring pattern in the concave part,
  • the polishing is finished when the substrate 30 or 130 having a desired pattern in which the cross section of the barrier metal part is exposed at the boundary between the convex part and the concave part is obtained. Further, the conductive material portion embedded in the recess may be polished together with the barrier metal portion.
  • a CMP polishing liquid is supplied between the polishing pad and the substrate with the surface to be polished facing the polishing pad and the substrate 20 or 120 pressed against the polishing pad of the polishing surface plate.
  • the surface to be polished is polished by relatively moving the polishing platen and the substrate 20 or 120.
  • a general polishing apparatus having a holder for holding a substrate to be polished and a polishing platen connected to a motor capable of changing the number of rotations and attached with a polishing pad is used. It can.
  • a polishing pad a general nonwoven fabric, foamed polyurethane, porous fluororesin, or the like can be used, and there is no particular limitation.
  • the polishing conditions are not particularly limited, but the rotation speed of the polishing surface plate is preferably a low rotation speed of 200 min ⁇ 1 or less so that the substrate does not pop out.
  • the pressure for pressing the substrate against the polishing pad is preferably 1 to 100 kPa, and more preferably 5 to 50 kPa in order to satisfy the in-surface uniformity of the polishing rate and the flatness of the pattern.
  • the CMP polishing liquid according to this embodiment is continuously supplied between the polishing pad and the surface to be polished by a pump or the like.
  • the supply amount is not limited, it is preferable that the surface of the polishing pad is always covered with a CMP polishing liquid.
  • the substrate after polishing is preferably washed in running water and then dried after removing water droplets adhering to the substrate using spin drying or the like.
  • the polishing pad is conditioned with a liquid containing at least water. Subsequently, it is preferable to perform a substrate cleaning step after performing the polishing method according to the present embodiment.
  • the CMP polishing liquid according to this embodiment can be used not only for polishing a semiconductor substrate as described above but also for polishing a substrate such as a magnetic head.
  • the present invention will be described more specifically by way of examples.
  • the present invention is not limited to these examples unless departing from the technical idea of the present invention.
  • the type of the polishing slurry for CMP and the mixing ratio thereof may be other types and mixing ratios than the types and mixing ratios described in the present embodiment.
  • the composition and structure to be polished may also be a composition and structure other than the composition and structure described in this example.
  • Examples 1 to 6 and Comparative Examples 1 and 2 A metal anticorrosive of the type shown in Table 1, 3-methoxy-3-methyl-1-butanol (organic solvent), ammonium polyacrylate (water-soluble polymer, weight average molecular weight 8,000), colloidal silica ( Abrasive grains (abrasive particles) and an average secondary particle size of 60 nm were placed in a container. Furthermore, after pouring ultrapure water, it was mixed by stirring to dissolve all components except the abrasive grains. After adding hydrogen peroxide water (30% by mass aqueous solution) as an oxidizing agent, ultrapure water was added to make the whole 100 parts by mass, and a polishing liquid for CMP was obtained.
  • hydrogen peroxide water (30% by mass aqueous solution) as an oxidizing agent
  • the content of each component is as shown in Table 1.
  • the content of abrasive grains is shown as mass% of “silica particles”, and the content of oxidizing agent is shown as mass% of “hydrogen peroxide”.
  • the average particle diameter (average secondary particle diameter) of colloidal silica and the weight average molecular weight of polyacrylic acid ammonium salt were measured according to the above-mentioned method.
  • ⁇ Measurement method of pH> The pH of the CMP polishing liquid was measured according to the following. Measurement temperature: 25 ° C Measuring instrument: “PHL-40” manufactured by Electrochemical Instruments Co., Ltd. Measurement method: standard buffer (phthalate pH buffer solution pH: 4.01 (25 ° C.), neutral phosphate pH buffer solution pH: 6.86 (25 ° C.), borate pH buffer solution pH: 9 After calibrating three points using .18 (25 ° C.), the electrode was placed in a polishing slurry for CMP, and the value after 3 minutes had elapsed and stabilized was measured, and the results are shown in Table 1.
  • a blanket substrate (a) in which a cobalt layer having a thickness of 200 nm was formed on a 12-inch silicon substrate was prepared.
  • the blanket substrate (a) was cut into 20 mm square chips to prepare evaluation chips (b).
  • the evaluation chip (b) was put in a beaker containing 100 g of each polishing agent (CMP polishing liquid) and immersed in a thermostat at 60 ° C. for 1 minute.
  • the evaluation chip (b) after immersion was taken out and thoroughly washed with pure water, and then nitrogen gas was blown to dry the water on the chip.
  • the resistance of the evaluation chip (b) after drying was measured with a resistivity meter, and converted into the thickness of the cobalt layer after immersion by the following formula (1).
  • a calibration curve was obtained from information on resistance values corresponding to the thicknesses of the blanket substrate (a), and the thickness of the cobalt layer was determined from the following formula (1).
  • Thickness [nm] of cobalt layer after immersion 104.5 ⁇ (resistance value [m ⁇ ] / 1000 for evaluation chip (b)) ⁇ 0.893 (1)
  • etching rate of the cobalt layer was calculated
  • Etching rate of cobalt layer (Co-ER) [nm / min] (thickness of cobalt layer before immersion [nm] ⁇ thickness of cobalt layer after immersion [nm]) / 1 minute (2)
  • Polishing device Polishing machine for single-sided metal film ("Reflexion LK" manufactured by Applied Materials) Polishing pad: Polishing pad made of polyurethane foam resin Platen rotation speed: 93 min ⁇ 1 Polishing head rotation speed: 87 min ⁇ 1 Polishing pressure: 10.3 kPa (1.5 psi) Supply amount of polishing liquid for CMP: 300 mL / min Polishing time: 0.5 min
  • the CMP polishing liquid and the polishing method according to the embodiment of the present invention it is possible to suppress the etching of cobalt while maintaining the polishing rate of the cobalt-containing portion as compared with the case of using the conventional CMP polishing liquid. .
  • SYMBOLS 1 Insulating material part, 2 ... Barrier metal part, 2a ... Cobalt containing part, 2b ... Barrier metal part, 3 ... Conductive substance part, 3a ... Metal containing part containing metals other than cobalt 10, 110, 210 ... Substrate before polishing, 20, 120, 220... Substrate after first polishing step, 30, 130, 230... Substrate after second polishing step.

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Abstract

A CMP polishing liquid that is used to polish a surface to be polished that has at least a cobalt-containing section and a metal-containing section that contains a metal that is not cobalt. The CMP polishing liquid contains polishing particles, two types of metal corrosion inhibitors, and water, and has a pH of 4.0 or less. The two types of metal corrosion inhibitors are both azoles (excluding salts of inorganic acids).

Description

ＣＭＰ用研磨液及びそれを用いた研磨方法Polishing liquid for CMP and polishing method using the same
　本発明は、ＣＭＰ用研磨液及びそれを用いた研磨方法に関する。 The present invention relates to a polishing slurry for CMP and a polishing method using the same.
　近年、半導体大規模集積回路（Ｌａｒｇｅ－Ｓｃａｌｅ　Ｉｎｔｅｇｒａｔｉｏｎ。以下、「ＬＳＩ」という。）の高集積化及び高性能化に伴って、新たな微細加工技術が開発されている。化学機械研磨（Ｃｈｅｍｉｃａｌ　Ｍｅｃｈａｎｉｃａｌ　Ｐｏｌｉｓｈｉｎｇ。以下、「ＣＭＰ」という。）法もその一つである。ＣＭＰ法は、ＬＳＩ製造工程（特に多層配線形成工程）における絶縁材料部の平坦化、金属プラグの形成、埋め込み配線の形成等において頻繁に利用される技術である。 In recent years, new microfabrication technology has been developed along with higher integration and higher performance of semiconductor large-scale integrated circuits (Large-Scale Integration; hereinafter referred to as “LSI”). Chemical mechanical polishing (Chemical Mechanical Polishing; hereinafter referred to as “CMP”) is one of them. The CMP method is a technique frequently used in planarization of an insulating material portion, formation of a metal plug, formation of a buried wiring, and the like in an LSI manufacturing process (particularly, a multilayer wiring forming process).
　近年、埋め込み配線の形成には、いわゆるダマシン法が採用されている。ダマシン法では、あらかじめ表面に凹部（例えば、溝部）及び凸部（例えば、隆起部）が形成された絶縁材料部上に導電性物質部を堆積して、凹部に導電性物質を埋め込む。次いで、凸部上に堆積した導電性物質（すなわち、凹部内以外の導電性物質）をＣＭＰ法により除去して埋め込み配線を形成する。 In recent years, the so-called damascene method has been adopted for the formation of embedded wiring. In the damascene method, a conductive material portion is deposited on an insulating material portion having a concave portion (for example, a groove portion) and a convex portion (for example, a raised portion) formed in advance on the surface, and the conductive material is embedded in the concave portion. Next, the conductive material deposited on the convex portion (that is, the conductive material other than in the concave portion) is removed by CMP to form a buried wiring.
　導電性物質部のＣＭＰでは、例えば、まず、円形の研磨定盤（プラテン）上に研磨パッドを貼り付け、研磨パッドの表面をＣＭＰ用研磨液で浸す。次に、基板の導電性物質部を形成した面を研磨パッドに押し付けて、基板の裏面から所定の圧力（以下、「研磨圧力」という。）を加える。その後、この状態で研磨定盤を回転させ、ＣＭＰ用研磨液と導電性物質部との機械的摩擦によって凸部上の導電性物質を除去する。 In the CMP of the conductive material portion, for example, first, a polishing pad is attached on a circular polishing platen (platen), and the surface of the polishing pad is immersed in a CMP polishing liquid. Next, the surface of the substrate on which the conductive material portion is formed is pressed against the polishing pad, and a predetermined pressure (hereinafter referred to as “polishing pressure”) is applied from the back surface of the substrate. Thereafter, the polishing surface plate is rotated in this state, and the conductive material on the convex portion is removed by mechanical friction between the CMP polishing liquid and the conductive material portion.
　一方、図３（ａ）に示すように、凹凸を有する絶縁材料部１と、当該絶縁材料部１の上部に設けられた導電性物質部３との間には、通常、バリア金属部２が形成される。バリア金属部２を設ける目的は、絶縁材料部１に導電性物質が拡散するのを防止すること、絶縁材料部１と導電性物質部３との密着性を向上させること等である。バリア金属部２は、バリア用の金属（以下、「バリア金属」という場合がある。）により形成される。バリア金属は導体であるため、導電性物質を埋め込む凹部（すなわち、配線部）以外では、導電性物質と同様にバリア金属を取り除く必要がある。 On the other hand, as shown in FIG. 3A, a barrier metal portion 2 is usually between the insulating material portion 1 having irregularities and the conductive material portion 3 provided on the insulating material portion 1. It is formed. The purpose of providing the barrier metal portion 2 is to prevent the conductive material from diffusing into the insulating material portion 1 and to improve the adhesion between the insulating material portion 1 and the conductive material portion 3. The barrier metal portion 2 is formed of a barrier metal (hereinafter sometimes referred to as “barrier metal”). Since the barrier metal is a conductor, it is necessary to remove the barrier metal in the same manner as the conductive material except for the concave portion (that is, the wiring portion) in which the conductive material is embedded.
　これらの除去には、図３（ａ）に示される状態から図３（ｂ）に示される状態まで導電性物質部３を研磨する「第一の研磨工程」と、図３（ｂ）に示される状態から図３（ｃ）に示される状態までバリア金属部２を研磨する「第二の研磨工程」とに分け、それぞれ異なるＣＭＰ用研磨液で研磨を行う二段研磨方法が一般に適用されている。 These removals include a “first polishing step” in which the conductive material portion 3 is polished from the state shown in FIG. 3A to the state shown in FIG. 3B, and the state shown in FIG. In general, a two-stage polishing method in which polishing is performed with different polishing liquids for CMP is applied to the “second polishing step” in which the barrier metal portion 2 is polished from the state shown in FIG. 3C to the state shown in FIG. Yes.
　ところで、デザインルールの微細化とともに、前記各部の厚さも薄くなる傾向がある。しかしながら、バリア金属部２は、薄くなることにより、導電性物質の拡散を防止する効果が低下する。また、バリア金属部２と導電性物質部３との密着性も低下する傾向がある。さらに、配線幅が狭くなることで、導電性物質を凹部に埋め込むのが難しくなり（すなわち、埋め込み性が低下し）、ボイドと呼ばれる空孔が導電性物質部３に発生し易くなるという、新たな課題が生じる。 By the way, as the design rules become finer, the thickness of each part tends to become thinner. However, the barrier metal part 2 is reduced in thickness, thereby reducing the effect of preventing the diffusion of the conductive substance. In addition, the adhesion between the barrier metal part 2 and the conductive substance part 3 tends to decrease. Furthermore, since the wiring width becomes narrower, it becomes difficult to embed the conductive material in the recess (that is, the embedding property is lowered), and voids called voids are easily generated in the conductive material part 3. Challenges arise.
　このため、バリア金属として、コバルト（Ｃｏ）の使用が検討されている。コバルトを用いることで、導電性物質の拡散が抑えられる。また、コバルトは、導電性物質（例えば、銅、銅合金等の銅系金属）との親和性が高いため、導電性物質の埋め込み性が向上する。さらに、コバルトは、絶縁材料と導電性物質との密着性を補うこともできる。 For this reason, the use of cobalt (Co) as a barrier metal has been studied. By using cobalt, diffusion of the conductive material can be suppressed. In addition, since cobalt has a high affinity with a conductive material (for example, a copper-based metal such as copper or a copper alloy), the embedding property of the conductive material is improved. Further, cobalt can supplement the adhesion between the insulating material and the conductive material.
　バリア金属部２にコバルトを用いる場合、コバルトを除去できるＣＭＰ用研磨液を用いる必要がある。金属用のＣＭＰ用研磨液としては種々のものが知られている。一方で、あるＣＭＰ用研磨液があったときに、そのＣＭＰ用研磨液がどのような金属も除去できるとは限らない。従来の金属用のＣＭＰ用研磨液としては、研磨によって除去する対象が、銅、タンタル、チタン、タングステン、アルミニウム等の金属である研磨液が知られている。しかしながら、コバルトを研磨対象とするＣＭＰ用研磨液は、下記特許文献１～３のように数例報告があるものの、あまり知られていない。 When using cobalt for the barrier metal part 2, it is necessary to use a polishing slurry for CMP that can remove cobalt. Various types of CMP polishing liquids for metals are known. On the other hand, when there is a CMP polishing liquid, the CMP polishing liquid cannot always remove any metal. As a conventional CMP polishing liquid for metal, a polishing liquid whose object to be removed by polishing is a metal such as copper, tantalum, titanium, tungsten, or aluminum is known. However, there are few known polishing liquids for CMP that use cobalt as an object of polishing, although several examples have been reported as in Patent Documents 1 to 3 below.
特開２０１１－９１２４８号公報JP 2011-91248 A 特開２０１２－１８２１５８号公報JP 2012-182158 A 特開２０１３－４２１２３号公報JP2013-42123A
　本発明者らの知見によれば、コバルトは、導電性物質として使用されてきた銅系金属等の金属と比較して腐食性が強いため、従来の金属用のＣＭＰ用研磨液をそのまま使用すると、コバルトが過度にエッチングされたり、配線パターンにスリットが生じたりする。その結果、バリア金属部としての機能を果たさずに、絶縁材料部に金属イオンが拡散する懸念がある。絶縁材料部に金属イオンが拡散した場合、半導体デバイスにショートが発生する可能性が高くなる。一方で、これを防ぐために、防食作用の強い金属防食剤をＣＭＰ用研磨液に添加したり、金属防食剤の添加量を増やしたりすると、コバルトの研磨速度が低下してしまう。 According to the knowledge of the present inventors, cobalt is more corrosive than metals such as copper-based metals that have been used as conductive materials. Cobalt is excessively etched or slits are formed in the wiring pattern. As a result, there is a concern that metal ions may diffuse into the insulating material portion without fulfilling the function as the barrier metal portion. When metal ions diffuse into the insulating material portion, there is a high possibility that a short circuit occurs in the semiconductor device. On the other hand, in order to prevent this, if a metal anticorrosive having a strong anticorrosive action is added to the CMP polishing liquid or the amount of the metal anticorrosive added is increased, the polishing rate of cobalt is lowered.
　本発明は、前記の課題を解決しようとするものであって、コバルトの良好な研磨速度を保ちながら、コバルトのエッチング速度を抑制することができるＣＭＰ用研磨液、及び、このＣＭＰ用研磨液を用いた研磨方法を提供することを目的とする。 The present invention is intended to solve the above-described problems, and provides a polishing slurry for CMP that can suppress the etching rate of cobalt while maintaining a good polishing rate of cobalt, and a polishing slurry for CMP. An object is to provide a polishing method used.
　このような従来の問題点を解決するために鋭意検討した結果、本発明者らは、特定の防食剤を使用することによって、コバルトの良好な研磨速度を保ちながら、コバルトのエッチング速度を効果的に抑制してコバルトを保護できることを見いだした。 As a result of intensive studies to solve such conventional problems, the present inventors have effectively increased the etching rate of cobalt while maintaining a good polishing rate of cobalt by using a specific anticorrosive. It was found that cobalt can be protected by suppressing it.
　すなわち、本発明の一実施形態は、コバルト含有部と、コバルト以外の金属を含有する金属含有部とを少なくとも有する被研磨面の研磨に用いられるＣＭＰ用研磨液であって、研磨粒子、２種類の金属防食剤、及び、水を含有し、ｐＨが４．０以下であり、前記２種類の金属防食剤がともにアゾール類（無機酸の塩を除く）である、ＣＭＰ用研磨液に関する。 That is, one embodiment of the present invention is a polishing slurry for CMP used for polishing a surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt. And a polishing slurry for CMP, which contains water and has a pH of 4.0 or less, and both of the two types of metal corrosion inhibitors are azoles (excluding salts of inorganic acids).
　本発明の一実施形態によれば、コバルト（例えばコバルト層）の良好な研磨速度を保ちながら、コバルト（例えばコバルト層）のエッチング速度を抑制することができる。本発明の一実施形態によれば、コバルトのエッチング速度を効果的に抑制してコバルトを保護できる。本発明の一実施形態によれば、例えば、コバルトのエッチング速度を１０ｎｍ／ｍｉｎ以下に抑制することができる。本発明の一実施形態によれば、コバルト、及び、金属材料（金属含有部を構成する材料。コバルトを除く）の研磨速度に優れる。 According to one embodiment of the present invention, the etching rate of cobalt (eg, cobalt layer) can be suppressed while maintaining a good polishing rate of cobalt (eg, cobalt layer). According to one embodiment of the present invention, cobalt can be protected by effectively suppressing the etching rate of cobalt. According to one embodiment of the present invention, for example, the etching rate of cobalt can be suppressed to 10 nm / min or less. According to one embodiment of the present invention, the polishing rate of cobalt and a metal material (a material constituting a metal-containing portion, excluding cobalt) is excellent.
　前記ＣＭＰ用研磨液の一実施形態は、水溶性ポリマを更に含有してもよい。これにより、コバルト含有部のガルバニック腐食の抑制、被研磨面の保護、欠陥（ディフェクト）発生の低減等が容易に可能である。 One embodiment of the CMP polishing liquid may further contain a water-soluble polymer. This makes it possible to easily suppress galvanic corrosion of the cobalt-containing portion, protect the surface to be polished, reduce the occurrence of defects, and the like.
　前記ＣＭＰ用研磨液の一実施形態において、前記研磨粒子は、シリカ粒子、アルミナ粒子、セリア粒子、チタニア粒子、ジルコニア粒子、ゲルマニア粒子及びこれらの変性物からなる群から選択される少なくとも一種を含んでもよい。これにより、金属材料（例えば、コバルト含有部の近傍に設けられた金属含有部の金属材料）の研磨速度が更に向上する傾向がある。 In one embodiment of the polishing slurry for CMP, the abrasive particles may include at least one selected from the group consisting of silica particles, alumina particles, ceria particles, titania particles, zirconia particles, germania particles, and modified products thereof. Good. Thereby, there exists a tendency for the grinding | polishing speed | rate of a metal material (For example, the metal material of the metal containing part provided in the vicinity of a cobalt containing part) to improve further.
　前記ＣＭＰ用研磨液の一実施形態は、金属酸化剤を更に含有することが好ましい。これにより、金属材料の研磨速度をより向上できる。 It is preferable that an embodiment of the polishing slurry for CMP further contains a metal oxidizing agent. Thereby, the grinding | polishing speed | rate of a metal material can be improved more.
　前記ＣＭＰ用研磨液の一実施形態は、有機溶媒を更に含有してもよい。これにより、金属含有部（例えば、コバルト含有部の近傍に設けられた金属含有部）の濡れ性を向上させることができ、金属材料の研磨速度をより向上できる。 One embodiment of the polishing slurry for CMP may further contain an organic solvent. Thereby, the wettability of a metal containing part (for example, the metal containing part provided in the vicinity of a cobalt containing part) can be improved, and the polishing rate of a metal material can be improved more.
　本発明の他の実施形態は、前記ＣＭＰ用研磨液を用いて、コバルト含有部と、コバルト以外の金属を含有する金属含有部とを少なくとも有する被研磨面の、前記コバルト含有部の少なくとも一部を研磨して除去する、研磨方法に関する。 In another embodiment of the present invention, at least a part of the cobalt-containing portion of the surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt, using the CMP polishing liquid. It is related with the grinding | polishing method which grind | polishes and removes.
　本発明の他の実施形態は、表面に凹部及び凸部を有する絶縁材料部と、前記凹部及び前記凸部に沿って前記絶縁材料部を被覆するバリア金属部と、前記凹部を充填して前記バリア金属部を被覆する導電性物質部とを有する基板を用意する工程、前記導電性物質部を研磨して前記凸部上の前記バリア金属部を露出させる第一の研磨工程、及び、前記ＣＭＰ用研磨液を用いて、前記第一の研磨工程で露出した前記バリア金属部を研磨して除去する第二の研磨工程を備え、前記バリア金属部が、コバルト含有部を有し、前記導電性物質部が、コバルト以外の金属を含有する金属含有部を有する、研磨方法に関する。 In another embodiment of the present invention, an insulating material portion having a concave portion and a convex portion on a surface thereof, a barrier metal portion covering the insulating material portion along the concave portion and the convex portion, and filling the concave portion are described above. Providing a substrate having a conductive material portion covering the barrier metal portion, a first polishing step of polishing the conductive material portion to expose the barrier metal portion on the convex portion, and the CMP A second polishing step of polishing and removing the barrier metal portion exposed in the first polishing step using a polishing slurry, wherein the barrier metal portion has a cobalt-containing portion, and the conductive property The material part has a metal-containing part containing a metal other than cobalt.
　前記研磨方法の一実施形態において、前記絶縁材料部は、シリコン系絶縁体及び有機ポリマ系絶縁体からなる群から選択される少なくとも一種であってもよい。 In one embodiment of the polishing method, the insulating material portion may be at least one selected from the group consisting of a silicon-based insulator and an organic polymer-based insulator.
　前記研磨方法の一実施形態において、前記導電性物質部は、銅を主成分としてもよい。 In one embodiment of the polishing method, the conductive material portion may contain copper as a main component.
　前記研磨方法の一実施形態において、前記バリア金属部は、前記コバルト含有部と、タンタル含有部、チタン含有部、タングステン含有部及びルテニウム含有部からなる群から選択される少なくとも一種とを有してもよい。 In one embodiment of the polishing method, the barrier metal part includes the cobalt-containing part and at least one selected from the group consisting of a tantalum-containing part, a titanium-containing part, a tungsten-containing part, and a ruthenium-containing part. Also good.
　本発明の実施形態によれば、コバルトの良好な研磨速度を保ちながら、コバルトのエッチング速度を抑制することができるＣＭＰ用研磨液と、このＣＭＰ用研磨液を用いた研磨方法とを提供できる。本発明の実施形態によれば、コバルトのエッチング速度を効果的に抑制してコバルトを保護できる。本発明の実施形態によれば、例えば、コバルトのエッチング速度を１０ｎｍ／ｍｉｎ以下に抑制することができる。本発明の実施形態によれば、コバルト含有部と、コバルト以外の金属を含有する金属含有部とを少なくとも有する被研磨面の研磨への研磨液の応用を提供することができる。 According to the embodiment of the present invention, it is possible to provide a CMP polishing liquid capable of suppressing the cobalt etching rate while maintaining a good cobalt polishing rate, and a polishing method using the CMP polishing liquid. According to the embodiment of the present invention, cobalt can be protected by effectively suppressing the etching rate of cobalt. According to the embodiment of the present invention, for example, the etching rate of cobalt can be suppressed to 10 nm / min or less. According to the embodiment of the present invention, it is possible to provide an application of a polishing liquid for polishing a surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt.
本発明の実施形態である研磨方法の一例を示す断面模式図である。It is a cross-sectional schematic diagram which shows an example of the grinding | polishing method which is embodiment of this invention. 本発明の実施形態である研磨方法の一例を示す断面模式図である。It is a cross-sectional schematic diagram which shows an example of the grinding | polishing method which is embodiment of this invention. 従来のダマシン法による埋め込み配線の形成工程を示す断面模式図である。It is a cross-sectional schematic diagram which shows the formation process of the embedded wiring by the conventional damascene method.
　本発明の実施形態において、「研磨速度」とは、ＣＭＰされる物質Ａが研磨により除去される速度（例えば、時間あたりの物質Ａの厚さの低減量。Ｒｅｍｏｖａｌ　Ｒａｔｅ。）を意味する。
　「工程」には、独立した工程だけではなく、他の工程と明確に区別できない場合であっても、当該「工程」において規定される操作が実施される限り、他の工程と明確に区別できない工程も含まれる。
　「～」を用いて示された数値範囲は、「～」の前後に記載される数値をそれぞれ最小値及び最大値として含む範囲を示す。
　ＣＭＰ用研磨液中の各成分の含有量は、各成分に該当する物質がＣＭＰ用研磨液中に複数存在する場合、特に断らない限り、ＣＭＰ用研磨液中に存在する当該複数の物質の合計量を意味する。 In the embodiment of the present invention, the “polishing rate” means a rate at which the material A to be CMP is removed by polishing (for example, a reduction amount of the thickness of the material A per time. Removable Rate).
“Process” is not only an independent process, but even if it cannot be clearly distinguished from other processes, it cannot be clearly distinguished from other processes as long as the operations specified in the “process” are performed. A process is also included.
The numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
The content of each component in the CMP polishing liquid is the sum of the plurality of substances present in the CMP polishing liquid, unless otherwise specified, when a plurality of substances corresponding to each component are present in the CMP polishing liquid. Means quantity.
　以下、本発明の実施形態について詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail.
＜ＣＭＰ用研磨液＞
　本実施形態に係るＣＭＰ用研磨液は、コバルト含有部と、コバルト以外の金属を含有する金属含有部とを少なくとも有する被研磨面の研磨に用いられるＣＭＰ用研磨液である。本実施形態に係るＣＭＰ用研磨液は、研磨粒子（以下、「砥粒」という場合がある。）、２種類の金属防食剤、及び、水を含有し、ｐＨが４．０以下である。 <CMP polishing liquid>
The CMP polishing liquid according to this embodiment is a CMP polishing liquid used for polishing a surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt. The polishing slurry for CMP according to this embodiment contains abrasive particles (hereinafter sometimes referred to as “abrasive grains”), two types of metal anticorrosives, and water, and has a pH of 4.0 or less.
（砥粒）
　ＣＭＰ用研磨液は、砥粒を含有する。砥粒の含有により、金属材料（例えば、コバルト含有部の近傍に設けられた金属含有部の金属材料）の研磨速度が向上する傾向がある。砥粒は、一種を単独で、又は、二種以上を混合して用いることができる。 (Abrasive grains)
The polishing liquid for CMP contains abrasive grains. The inclusion of abrasive grains tends to improve the polishing rate of a metal material (for example, a metal material of a metal-containing portion provided in the vicinity of the cobalt-containing portion). An abrasive grain can be used individually by 1 type or in mixture of 2 or more types.
　砥粒としては、シリカ粒子、アルミナ粒子、セリア粒子、チタニア粒子、ジルコニア粒子、ゲルマニア粒子、炭化ケイ素粒子等の無機物研磨粒子；ポリスチレン粒子、ポリアクリル酸粒子、ポリ塩化ビニル粒子等の有機物研磨粒子；これらの変性物（変性物粒子）などが挙げられる。 As abrasive grains, inorganic abrasive particles such as silica particles, alumina particles, ceria particles, titania particles, zirconia particles, germania particles and silicon carbide particles; organic abrasive particles such as polystyrene particles, polyacrylic acid particles and polyvinyl chloride particles; These modified products (modified product particles) are exemplified.
　砥粒としては、好ましくは、シリカ粒子、アルミナ粒子、セリア粒子、チタニア粒子、ジルコニア粒子、ゲルマニア粒子及びこれらの変性物からなる群から選択される少なくとも一種である。 The abrasive grains are preferably at least one selected from the group consisting of silica particles, alumina particles, ceria particles, titania particles, zirconia particles, germania particles, and modified products thereof.
　ＣＭＰ用研磨液中での分散安定性が良く、ＣＭＰにより発生する研磨傷（「スクラッチ」という場合がある。）の発生数が少ない観点から、シリカ粒子及びアルミナ粒子からなる群から選択される少なくとも一種が好ましく、コロイダルシリカ及びコロイダルアルミナからなる群から選択される少なくとも一種がより好ましく、コロイダルシリカが更に好ましい。 At least selected from the group consisting of silica particles and alumina particles from the viewpoint of good dispersion stability in the CMP polishing liquid and a small number of polishing scratches (sometimes referred to as “scratches”) generated by CMP. One type is preferable, at least one selected from the group consisting of colloidal silica and colloidal alumina is more preferable, and colloidal silica is more preferable.
　砥粒の含有量は、コバルトの更に良好な研磨速度を得る観点から、ＣＭＰ用研磨液の総質量中、好ましくは１．０質量％以上、より好ましくは１．２質量％以上、更に好ましくは１．５質量％以上、特に好ましくは２．０質量％以上である。また、砥粒の含有量は、砥粒の良好な分散安定性を維持し、研磨傷の発生を抑える観点から、ＣＭＰ用研磨液の総質量中、好ましくは５．０質量％以下、より好ましくは４．５質量％以下、更に好ましくは４．０質量％以下、特に好ましくは３．０質量％以下である。 The content of the abrasive grains is preferably 1.0% by mass or more, more preferably 1.2% by mass or more, and still more preferably from the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt. It is 1.5% by mass or more, particularly preferably 2.0% by mass or more. The content of the abrasive grains is preferably 5.0% by mass or less, more preferably 5.0% by mass or less, based on the total mass of the polishing slurry for CMP, from the viewpoint of maintaining good dispersion stability of the abrasive grains and suppressing the occurrence of polishing flaws. Is 4.5% by mass or less, more preferably 4.0% by mass or less, and particularly preferably 3.0% by mass or less.
　砥粒の平均粒径（平均二次粒径）は、コバルトの更に良好な研磨速度を得る観点から、好ましくは４０ｎｍ以上、より好ましくは４５ｎｍ以上、更に好ましくは５０ｎｍ以上、特に好ましくは６０ｎｍ以上である。また、砥粒の平均粒径は、研磨傷を抑える観点から、好ましくは９０ｎｍ以下、より好ましくは８５ｎｍ以下、更に好ましくは８０ｎｍ以下、特に好ましくは７０ｎｍ以下である。 The average particle size (average secondary particle size) of the abrasive grains is preferably 40 nm or more, more preferably 45 nm or more, still more preferably 50 nm or more, and particularly preferably 60 nm or more, from the viewpoint of obtaining a better polishing rate of cobalt. is there. The average grain size of the abrasive grains is preferably 90 nm or less, more preferably 85 nm or less, still more preferably 80 nm or less, and particularly preferably 70 nm or less from the viewpoint of suppressing polishing flaws.
　砥粒の粒径は、ＣＭＰ用研磨液を適宜水で希釈した水分散液をサンプルとして、光回折散乱式粒度分布計（例えば、ＣＯＵＬＴＥＲ　Ｅｌｅｃｔｒｏｎｉｃｓ社製「ＣＯＵＬＴＥＲ　Ｎ４ＳＤ」）で測定できる。例えば、光回折散乱式粒度分布計の測定条件は、測定温度２０℃、溶媒屈折率１．３３３（水の屈折率に相当）、粒子屈折率Ｕｎｋｎｏｗｎ（設定）、溶媒粘度１．００５ｍＰａ・ｓ（水の粘度に相当）、Ｒｕｎ　Ｔｉｍｅ２００ｓｅｃ、レーザ入射角９０°とすることができる。また、Ｉｎｔｅｎｓｉｔｙ（散乱強度、濁度に相当）が４×１０５よりも高い場合には、５×１０４～４×１０５の範囲に入るようにＣＭＰ用研磨液を水で希釈して水分散液を得た後、測定することができる。 The particle diameter of the abrasive grains can be measured with a light diffraction scattering type particle size distribution meter (for example, “COULTER N4SD” manufactured by COULTER Electronics) using a water dispersion obtained by appropriately diluting a CMP polishing liquid with water as a sample. For example, the measurement conditions of a light diffraction / scattering particle size distribution meter are: measurement temperature 20 ° C., solvent refractive index 1.333 (corresponding to the refractive index of water), particle refractive index Unknown (setting), solvent viscosity 1.005 mPa · s ( Equivalent to the viscosity of water), Run Time 200 sec, and laser incident angle 90 °. Further, Intensity if (scattering intensity, corresponds to turbidity) is higher than 4 × 10 5 is a CMP polishing liquid to fall in the range of 5 × 10 4 ~ 4 × 10 5 was diluted with water water After obtaining the dispersion, it can be measured.
（金属防食剤）
　ＣＭＰ用研磨液は、２種類の金属防食剤を含有する。２種類の金属防食剤の含有により、コバルトの良好な研磨速度を保ちながらコバルトのエッチング速度を１０ｎｍ／ｍｉｎ以下に抑制できる。 (Metal anticorrosive)
The CMP polishing liquid contains two types of metal anticorrosives. By containing two types of metal anticorrosive agents, the etching rate of cobalt can be suppressed to 10 nm / min or less while maintaining a good polishing rate of cobalt.
　２種類の金属防食剤は、コバルトの良好な研磨速度を保ちながら、コバルト含有部のエッチングを抑制する観点から、アゾール類（アゾール骨格を有する化合物。アゾール類の無機酸塩を除く）から選択される。ＣＭＰ用研磨液は、３種類以上のアゾール類を含有していてもよい。ＣＭＰ用研磨液は、アゾール類以外の金属防食剤を含有していてもよい。ＣＭＰ用研磨液は、アゾール類の無機酸塩に該当しない少なくとも２種類のアゾール類を含有する。 Two types of metal anticorrosives are selected from azoles (compounds having an azole skeleton, excluding inorganic salts of azoles) from the viewpoint of suppressing etching of the cobalt-containing portion while maintaining a good polishing rate of cobalt. The The CMP polishing liquid may contain three or more types of azoles. The CMP polishing liquid may contain a metal anticorrosive other than azoles. The polishing liquid for CMP contains at least two kinds of azoles that do not correspond to inorganic acid salts of azoles.
　アゾール類としては、具体的には、ピラゾール類（ピラゾール骨格を有する化合物）、イミダゾール類（イミダゾール骨格を有する化合物）、チアゾール類（チアゾール骨格を有する化合物。ベンゾチアゾール類に該当する化合物を除く）、ベンゾチアゾール類（ベンゾチアゾール骨格を有する化合物）、テトラゾール類（テトラゾール骨格を有する化合物）、トリアゾール類（トリアゾール骨格を有する化合物。ベンゾトリアゾール類に該当する化合物を除く）及びベンゾトリアゾール類（ベンゾトリアゾール骨格を有する化合物）からなる群から選択される少なくとも一種を用いることができる。 Specific examples of azoles include pyrazoles (compounds having a pyrazole skeleton), imidazoles (compounds having an imidazole skeleton), thiazoles (compounds having a thiazole skeleton, excluding compounds corresponding to benzothiazoles), Benzothiazoles (compounds having a benzothiazole skeleton), tetrazoles (compounds having a tetrazole skeleton), triazoles (compounds having a triazole skeleton, excluding compounds corresponding to benzotriazoles), and benzotriazoles (benzotriazole skeletons) At least one selected from the group consisting of:
　ピラゾール類としては、ピラゾール、１Ｈ－ピラゾール－３，５－ジカルボン酸、１－アリル－３，５－ジメチルピラゾール、３，５－ジ（２－ピリジル）ピラゾール、３，５－ジイソプロピルピラゾール、３，５－ジメチル－１－ヒドロキシメチルピラゾール、３，５－ジメチル－１－フェニルピラゾール、３，５－ジメチルピラゾール、３－アミノ－５－ヒドロキシピラゾール、４－メチルピラゾール、Ｎ－メチルピラゾール、３－アミノピラゾール、３－アミノ－５－メチルピラゾール等が挙げられる。イミダゾール類としては、１，１’－カルボニルビス－１Ｈ－イミダゾール、１，１’－オキサリルジイミダゾール、１，２，４，５－テトラメチルイミダゾール、１，２－ジメチル－５－ニトロイミダゾール、１，２－ジメチルイミダゾール、１－（３－アミノプロピル）イミダゾール、１－ブチルイミダゾール、１－エチルイミダゾール、１－メチルイミダゾール、１Ｈ－１，２，３－トリアゾロ［４，５－ｂ］ピリジン等が挙げられる。チアゾール類としては、２，４－ジメチルチアゾール等が挙げられる。ベンゾチアゾール類としては、２－メルカプトベンゾチアゾール等が挙げられる。テトラゾール類としては、テトラゾール、５－メチルテトラゾール、５－アミノテトラゾール、５－アミノ－１－ヒドロキシテトラゾール、１，５－ペンタメチレンテトラゾール、１－（２－ジメチルアミノエチル）－５－メルカプトテトラゾール等が挙げられる。トリアゾール類としては、１，２，３－トリアゾ－ル、１，２，４－トリアゾ－ル、３－アミノ－１，２，４－トリアゾ－ル等が挙げられる。ベンゾトリアゾール類としては、ベンゾトリアゾ－ル、１－ヒドロキシベンゾトリアゾ－ル、１－ジヒドロキシプロピルベンゾトリアゾ－ル、２，３－ジカルボキシプロピルベンゾトリアゾ－ル、４－ヒドロキシベンゾトリアゾ－ル、４－カルボキシベンゾトリアゾ－ル、５－メチルベンゾトリアゾール、１－（ホルムアミドメチル）－１Ｈ－ベンゾトリアゾール等が挙げられる。 Pyrazoles include pyrazole, 1H-pyrazole-3,5-dicarboxylic acid, 1-allyl-3,5-dimethylpyrazole, 3,5-di (2-pyridyl) pyrazole, 3,5-diisopropylpyrazole, 3, 5-dimethyl-1-hydroxymethylpyrazole, 3,5-dimethyl-1-phenylpyrazole, 3,5-dimethylpyrazole, 3-amino-5-hydroxypyrazole, 4-methylpyrazole, N-methylpyrazole, 3-amino Examples include pyrazole and 3-amino-5-methylpyrazole. Examples of imidazoles include 1,1′-carbonylbis-1H-imidazole, 1,1′-oxalyldiimidazole, 1,2,4,5-tetramethylimidazole, 1,2-dimethyl-5-nitroimidazole, 1,2-dimethylimidazole, 1- (3-aminopropyl) imidazole, 1-butylimidazole, 1-ethylimidazole, 1-methylimidazole, 1H-1,2,3-triazolo [4,5-b] pyridine, etc. Can be mentioned. Examples of thiazoles include 2,4-dimethylthiazole. Examples of benzothiazoles include 2-mercaptobenzothiazole. Examples of tetrazoles include tetrazole, 5-methyltetrazole, 5-aminotetrazole, 5-amino-1-hydroxytetrazole, 1,5-pentamethylenetetrazole, 1- (2-dimethylaminoethyl) -5-mercaptotetrazole and the like. Can be mentioned. Examples of triazoles include 1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole and the like. Benzotriazoles include benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole 4-carboxybenzotriazole, 5-methylbenzotriazole, 1- (formamidomethyl) -1H-benzotriazole and the like.
　コバルトの良好な研磨速度を保ちながらコバルト含有部のエッチングを更に効果的に抑制する観点から、金属防食剤は、ピラゾール類、イミダゾール類、チアゾール類、ベンゾチアゾール類及びテトラゾール類からなる群から選択される少なくとも一種であることが好ましく、ベンゾトリアゾール類であることがより好ましい。 The metal anticorrosive agent is selected from the group consisting of pyrazoles, imidazoles, thiazoles, benzothiazoles and tetrazoles from the viewpoint of further effectively suppressing the etching of the cobalt-containing portion while maintaining a good polishing rate of cobalt. At least one kind is preferred, and benzotriazoles are more preferred.
　金属防食剤の含有量（総含有量）は、コバルト含有部のガルバニック腐食を更に抑制する観点から、ＣＭＰ用研磨液の総質量中、好ましくは０．００１質量％以上、より好ましくは０．０１質量％以上、更に好ましくは０．０２質量％以上、特に好ましくは０．０５質量％以上、極めて好ましくは０．１質量％以上、非常に好ましくは０．２質量％以上である。また、金属防食剤の含有量は、コバルトの更に良好な研磨速度を得る観点から、ＣＭＰ用研磨液の総質量中、好ましくは５質量％以下、より好ましくは３質量％以下、更に好ましくは１質量％以下、特に好ましくは０．５質量％以下である。 The content (total content) of the metal anticorrosive is preferably 0.001% by mass or more, more preferably 0.01% in the total mass of the polishing slurry for CMP, from the viewpoint of further suppressing galvanic corrosion of the cobalt-containing part. % By mass or more, more preferably 0.02% by mass or more, particularly preferably 0.05% by mass or more, very preferably 0.1% by mass or more, and very preferably 0.2% by mass or more. In addition, the content of the metal anticorrosive is preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 1% in the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt. It is not more than mass%, particularly preferably not more than 0.5 mass%.
（有機酸類）
　ＣＭＰ用研磨液は、有機酸類を更に含有してもよい。有機酸類は、コバルト及び金属材料の研磨速度を更に向上させる効果を有する。有機酸類は、有機酸、有機酸の塩、有機酸の無水物及び有機酸のエステルからなる群から選択される少なくとも一種であってもよい。有機酸類の中でも、コバルト含有部の腐食を更に抑制する観点から、フタル酸類が好ましい。フタル酸類を用いることにより、コバルトの更に良好な研磨速度が得られるとともに、腐食を更に抑制できる。フタル酸類は、フタル酸、フタル酸の塩、フタル酸の無水物及びフタル酸のエステルからなる群から選択される少なくとも一種であってもよい。有機酸類（フタル酸類等）は、置換基を有してもよく、置換基を有しなくてもよい。有機酸類は、一種を単独で、又は、二種以上を混合して用いることができる。 (Organic acids)
The CMP polishing liquid may further contain organic acids. Organic acids have the effect of further improving the polishing rate of cobalt and metal materials. The organic acids may be at least one selected from the group consisting of organic acids, organic acid salts, organic acid anhydrides, and organic acid esters. Among organic acids, phthalic acids are preferable from the viewpoint of further suppressing corrosion of the cobalt-containing part. By using phthalic acids, a better polishing rate of cobalt can be obtained, and corrosion can be further suppressed. The phthalic acids may be at least one selected from the group consisting of phthalic acid, phthalic acid salts, phthalic anhydrides and phthalic acid esters. Organic acids (phthalic acid etc.) may have a substituent and may not have a substituent. The organic acids can be used singly or in combination of two or more.
　フタル酸類としては、フタル酸；３－メチルフタル酸、４－メチルフタル酸等のアルキルフタル酸；３－アミノフタル酸、４－アミノフタル酸等のアミノフタル酸；３－ニトロフタル酸、４－ニトロフタル酸等のニトロフタル酸；これらの塩；これらの無水物；これらのエステルなどが挙げられる。中でも、メチル基を置換基として有するフタル酸（メチルフタル酸）が好ましく、３－メチルフタル酸及び４－メチルフタル酸からなる群から選択される少なくとも一種がより好ましく、４－メチルフタル酸が更に好ましい。塩としては、ナトリウム、カリウム等のアルカリ金属との塩；マグネシウム、カルシウム等のアルカリ土類金属との塩；アンモニウム塩などが挙げられる。 Examples of phthalic acids include: phthalic acid; alkylphthalic acid such as 3-methylphthalic acid and 4-methylphthalic acid; aminophthalic acid such as 3-aminophthalic acid and 4-aminophthalic acid; nitrophthalic acid such as 3-nitrophthalic acid and 4-nitrophthalic acid These salts; their anhydrides; their esters and the like. Among these, phthalic acid having a methyl group as a substituent (methylphthalic acid) is preferable, at least one selected from the group consisting of 3-methylphthalic acid and 4-methylphthalic acid is more preferable, and 4-methylphthalic acid is still more preferable. Examples of the salt include salts with alkali metals such as sodium and potassium; salts with alkaline earth metals such as magnesium and calcium; ammonium salts and the like.
　ＣＭＰ用研磨液が有機酸類を含有する場合、有機酸類の含有量は、コバルト含有部のガルバニック腐食を更に抑制する観点から、ＣＭＰ用研磨液の総質量中、好ましくは０．００１質量％以上、より好ましくは０．０１質量％以上、更に好ましくは０．０２質量％以上である。また、有機酸類の含有量は、コバルトの更に良好な研磨速度を得る観点から、ＣＭＰ用研磨液の総質量中、好ましくは５質量％以下、より好ましくは３質量％以下、更に好ましくは１質量％以下である。 When the CMP polishing liquid contains organic acids, the content of the organic acids is from the viewpoint of further suppressing the galvanic corrosion of the cobalt-containing part, preferably 0.001% by mass or more in the total mass of the CMP polishing liquid. More preferably, it is 0.01 mass% or more, More preferably, it is 0.02 mass% or more. The content of the organic acid is preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 1% by mass in the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt. % Or less.
（金属酸化剤）
　ＣＭＰ用研磨液は、金属酸化剤を含有することが好ましい。金属酸化剤としては、特に制限はないが、過酸化水素、ペルオキソ硫酸塩、硝酸、過ヨウ素酸カリウム、次亜塩素酸、オゾン等が挙げられる。コバルト及び金属材料の研磨速度を更に向上させる観点から、過酸化水素が特に好ましい。金属酸化剤は、一種を単独で、又は、二種以上を混合して用いることができる。 (Metal oxidizer)
The CMP polishing liquid preferably contains a metal oxidizing agent. The metal oxidizing agent is not particularly limited, and examples thereof include hydrogen peroxide, peroxosulfate, nitric acid, potassium periodate, hypochlorous acid, and ozone. From the viewpoint of further improving the polishing rate of cobalt and metal materials, hydrogen peroxide is particularly preferable. A metal oxidizing agent can be used individually by 1 type or in mixture of 2 or more types.
　ＣＭＰ用研磨液が金属酸化剤を含有する場合、金属酸化剤の含有量は、コバルト及び金属材料の更に良好な研磨速度を得る観点から、ＣＭＰ用研磨液の総質量中、０．０１質量％以上が好ましく、０．０２質量％以上が好ましく、０．０５質量％以上が更に好ましい。また、金属酸化剤の含有量は、被研磨面の荒れを防ぐ観点から、３０質量％以下が好ましく、１５質量％以下がより好ましく、１０質量％以下が更に好ましく、５質量％以下が特に好ましく、１質量％以下が極めて好ましく、０．５質量％以下が非常に好ましく、０．１質量％以下がより一層好ましい。 When the polishing slurry for CMP contains a metal oxidizer, the content of the metal oxidizer is 0.01% by mass in the total mass of the polishing slurry for CMP from the viewpoint of obtaining a better polishing rate of cobalt and the metal material. The above is preferable, 0.02% by mass or more is preferable, and 0.05% by mass or more is more preferable. The content of the metal oxidant is preferably 30% by mass or less, more preferably 15% by mass or less, still more preferably 10% by mass or less, and particularly preferably 5% by mass or less, from the viewpoint of preventing roughness of the surface to be polished. 1 mass% or less is very preferable, 0.5 mass% or less is very preferable, and 0.1 mass% or less is still more preferable.
（有機溶媒）
　ＣＭＰ用研磨液は、有機溶媒を更に含有してもよい。有機溶媒の含有により、金属含有部（例えば、コバルト含有部の近傍に設けられた金属含有部）に対するＣＭＰ用研磨液の濡れ性を向上させることができる。有機溶媒としては、特に制限はないが、水と混合できる溶媒が好ましく、２５℃において水１００ｇに対して０．１ｇ以上溶解する溶媒がより好ましい。有機溶媒は、一種を単独で、又は、二種以上を混合して用いることができる。 (Organic solvent)
The CMP polishing liquid may further contain an organic solvent. By including the organic solvent, the wettability of the polishing slurry for CMP with respect to the metal-containing part (for example, the metal-containing part provided in the vicinity of the cobalt-containing part) can be improved. Although there is no restriction | limiting in particular as an organic solvent, The solvent which can be mixed with water is preferable, and the solvent which melt | dissolves 0.1g or more with respect to 100g of water at 25 degreeC is more preferable. An organic solvent can be used individually by 1 type or in mixture of 2 or more types.
　有機溶媒としては、エチレンカーボネート、プロピレンカーボネート、ジメチルカーボネート、ジエチルカーボネート、メチルエチルカーボネート等の炭酸エステル類；ブチルラクトン、プロピルラクトン等のラクトン類；エチレングリコール、プロピレングリコール、ジエチレングリコール、ジプロピレングリコール、トリエチレングリコール、トリプロピレングリコール等のグリコール類；グリコール類の誘導体；テトラヒドロフラン、ジオキサン、ジメトキシエタン、ポリエチレンオキサイド、エチレングリコールモノメチルエーテルアセテート、ジエチレングリコールモノエチルエーテルアセテート、プロピレングリコールモノメチルエーテルアセテート等のエーテル類（グリコール類の誘導体を除く）；メタノール、エタノール、プロパノール、ｎ－ブタノール、ｎ－ペンタノール、ｎ－ヘキサノール、イソプロパノール、３－メトキシ－３－メチル－１－ブタノール等のアルコール類（モノアルコール類）；アセトン、メチルエチルケトン等のケトン類；ジメチルホルムアミド、Ｎ－メチルピロリドン等のアミド類；酢酸エチル、乳酸エチル等のエステル類（炭酸エステル及びラクトン類を除く）；スルホラン等のスルホラン類などが挙げられる。 Organic solvents include carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate; lactones such as butyl lactone and propyl lactone; ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene Glycols such as glycol and tripropylene glycol; derivatives of glycols; ethers such as tetrahydrofuran, dioxane, dimethoxyethane, polyethylene oxide, ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (glycols) Excluding derivatives); methanol, ethanol Alcohols (monoalcohols) such as propanol, n-butanol, n-pentanol, n-hexanol, isopropanol, 3-methoxy-3-methyl-1-butanol; ketones such as acetone and methyl ethyl ketone; dimethylformamide, N -Amides such as methylpyrrolidone; Esters such as ethyl acetate and ethyl lactate (excluding carbonates and lactones); and sulfolanes such as sulfolane.
　有機溶媒は、グリコール類の誘導体であってもよい。グリコール類の誘導体としては、エチレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテル、ジエチレングリコールモノメチルエーテル、ジプロピレングリコールモノメチルエーテル、トリエチレングリコールモノメチルエーテル、トリプロピレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、プロピレングリコールモノエチルエーテル、ジエチレングリコールモノエチルエーテル、ジプロピレングリコールモノエチルエーテル、トリエチレングリコールモノエチルエーテル、トリプロピレングリコールモノエチルエーテル、エチレングリコールモノプロピルエーテル、プロピレングリコールモノプロピルエーテル、ジエチレングリコールモノプロピルエーテル、トリエチレングリコールモノプロピルエーテル、トリプロピレングリコールモノプロピルエーテル、エチレングリコールモノブチルエーテル、プロピレングリコールモノブチルエーテル、ジエチレングリコールモノブチルエーテル、トリプロピレングリコールモノブチルエーテル、トリエチレングリコールモノブチルエーテル、トリプロピレングリコールモノブチルエーテル等のグリコールモノエーテル類；エチレングリコールジメチルエーテル、プロピレングリコールジメチルエーテル、ジエチレングリコールジメチルエーテル、ジプロピレングリコールジメチルエーテル、トリエチレングリコールジメチルエチルエーテル、トリプロピレングリコールジメチルエーテル、エチレングリコールジエチルエーテル、プロピレングリコールジエチルエーテル、ジエチレングリコールジエチルエーテル、ジプロピレングリコールジエチルエーテル、トリエチレングリコールジエチルエーテル、トリプロピレングリコールジエチルエーテル、エチレングリコールジプロピルエーテル、プロピレングリコールジプロピルエーテル、ジエチレングリコールジプロピルエーテル、ジプロピレングリコールジプロピルエーテル、トリエチレングリコールジプロピルエーテル、トリプロピレングリコールジプロピルエーテル、エチレングリコールジブチルエーテル、プロピレングリコールジブチルエーテル、ジエチレングリコールジブチルエーテル、ジプロピレングリコールジブチルエーテル、トリエチレングリコールジブチルエーテル、トリプロピレングリコールジブチルエーテル等のグリコールエーテル類などが挙げられる。 The organic solvent may be a derivative of glycols. Examples of glycol derivatives include ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether. , Diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether, tripropylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol Glycol monoethers such as monopropyl ether, tripropylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, diethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether; ethylene Glycol dimethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, triethylene glycol dimethyl ethyl ether, tripropylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol diethyl ether, diethyl Glycol diethyl ether, dipropylene glycol diethyl ether, triethylene glycol diethyl ether, tripropylene glycol diethyl ether, ethylene glycol dipropyl ether, propylene glycol dipropyl ether, diethylene glycol dipropyl ether, dipropylene glycol dipropyl ether, triethylene glycol Examples include glycol ethers such as dipropyl ether, tripropylene glycol dipropyl ether, ethylene glycol dibutyl ether, propylene glycol dibutyl ether, diethylene glycol dibutyl ether, dipropylene glycol dibutyl ether, triethylene glycol dibutyl ether, and tripropylene glycol dibutyl ether. Et It is.
　有機溶媒としては、グリコール類、グリコール類の誘導体、アルコール類及び炭酸エステル類からなる群から選択される少なくとも一種が好ましく、アルコール類がより好ましい。 The organic solvent is preferably at least one selected from the group consisting of glycols, glycol derivatives, alcohols and carbonates, and more preferably alcohols.
　ＣＭＰ用研磨液が有機溶媒を含有する場合、有機溶媒の含有量は、金属含有部に対して良好な濡れ性を得る観点から、ＣＭＰ用研磨液の総質量中、０．１質量％以上が好ましく、０．２質量％以上がより好ましく、０．５質量％以上が更に好ましく、１質量％以上が特に好ましく、１．２質量％以上が極めて好ましい。また、有機溶媒の含有量は、引火の可能性を防止し、製造プロセスを安全に実施する観点から、ＣＭＰ用研磨液の総質量中、９５質量％以下が好ましく、５０質量％以下がより好ましく、１０質量％以下が更に好ましく、５質量％以下が特に好ましく、３質量％以下が極めて好ましく、２質量％以下が非常に好ましく、１．５質量％以下がより一層好ましい。 When the CMP polishing liquid contains an organic solvent, the content of the organic solvent is 0.1% by mass or more in the total mass of the CMP polishing liquid from the viewpoint of obtaining good wettability with respect to the metal-containing portion. It is preferably 0.2% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and extremely preferably 1.2% by mass or more. Further, the content of the organic solvent is preferably 95% by mass or less and more preferably 50% by mass or less in the total mass of the polishing slurry for CMP from the viewpoint of preventing the possibility of ignition and safely implementing the manufacturing process. 10 mass% or less is further more preferable, 5 mass% or less is especially preferable, 3 mass% or less is very preferable, 2 mass% or less is very preferable, and 1.5 mass% or less is much more preferable.
（水溶性ポリマ）
　ＣＭＰ用研磨液は、水溶性ポリマを更に含有してもよい。水溶性ポリマの含有により、コバルト含有部のガルバニック腐食の抑制、被研磨面の保護、欠陥（ディフェクト）発生の低減等が容易に可能である。水溶性ポリマは、２５℃において水１００ｇに対して０．１ｇ以上溶解するポリマが好ましい。水溶性ポリマは、一種を単独で、又は、二種以上を混合して用いることができる。 (Water-soluble polymer)
The CMP polishing liquid may further contain a water-soluble polymer. By containing the water-soluble polymer, it is possible to easily suppress the galvanic corrosion of the cobalt-containing portion, protect the surface to be polished, reduce the occurrence of defects, and the like. The water-soluble polymer is preferably a polymer that dissolves 0.1 g or more in 100 g of water at 25 ° C. A water-soluble polymer can be used individually by 1 type or in mixture of 2 or more types.
　水溶性ポリマとしては、カルボン酸基及びカルボン酸塩基からなる群から選択される少なくとも一種を有する水溶性ポリマが好ましく、ポリカルボン酸及びその塩（「ポリカルボン酸の塩」とは、「ポリカルボン酸のカルボン酸基の一部又は全部がカルボン酸塩基に置換されたポリマ」を意味する。）がより好ましい。カルボン酸塩基としては、カルボン酸アンモニウム基、カルボン酸ナトリウム基等が挙げられる。 The water-soluble polymer is preferably a water-soluble polymer having at least one selected from the group consisting of a carboxylic acid group and a carboxylic acid group. The polycarboxylic acid and its salt (“polycarboxylic acid salt” means “polycarboxylic acid”). More preferably, it means “polymer in which part or all of the carboxylic acid groups of the acid are substituted with carboxylic acid groups”. Examples of the carboxylate group include an ammonium carboxylate group and a sodium carboxylate group.
　ポリカルボン酸及びその塩としては、アクリル酸、メタクリル酸、マレイン酸等の、カルボン酸基を有するモノマーの単独重合体；前記単独重合体のカルボン酸基の一部又は全部がカルボン酸塩基に置換された重合体；アクリル酸、メタクリル酸、マレイン酸等の、カルボン酸基を有するモノマーと、カルボン酸のアルキルエステル等のカルボン酸誘導体との共重合体；前記共重合体のカルボン酸基の一部又は全部がカルボン酸塩基に置換された共重合体などが挙げられる。具体的には、ポリアクリル酸；ポリアクリル酸アンモニウム塩（「ポリアクリル酸のカルボン酸基の一部又は全部がカルボン酸アンモニウム塩基に置換されたポリマ」を意味する。）等が挙げられる。 Polycarboxylic acids and salts thereof include homopolymers of monomers having a carboxylic acid group, such as acrylic acid, methacrylic acid, and maleic acid; some or all of the carboxylic acid groups of the homopolymer are substituted with carboxylic acid groups A copolymer of a monomer having a carboxylic acid group such as acrylic acid, methacrylic acid or maleic acid and a carboxylic acid derivative such as an alkyl ester of carboxylic acid; one of the carboxylic acid groups of the copolymer Examples thereof include a copolymer in which part or all is substituted with a carboxylate group. Specific examples include polyacrylic acid; polyacrylic acid ammonium salt (meaning “a polymer in which part or all of the carboxylic acid group of polyacrylic acid is substituted with a carboxylic acid ammonium base”) and the like.
　その他の水溶性ポリマとしては、ポリアスパラギン酸、ポリグルタミン酸、ポリリシン、ポリリンゴ酸、ポリアミド酸、ポリアミド酸アンモニウム塩、ポリアミド酸ナトリウム塩、ポリグリオキシル酸等の、上記以外のポリカルボン酸及びその塩；アルギン酸、ペクチン酸、カルボキシメチルセルロース、寒天、カードラン、プルラン等の多糖類；ポリビニルアルコール、ポリビニルピロリドン、ポリアクロレイン等のビニル系ポリマなどが挙げられる。 Other water-soluble polymers include polyaspartic acid, polyglutamic acid, polylysine, polymalic acid, polyamic acid, polyamic acid ammonium salt, polyamic acid sodium salt, polyglyoxylic acid and other polycarboxylic acids and salts thereof; alginic acid And polysaccharides such as pectinic acid, carboxymethylcellulose, agar, curdlan and pullulan; and vinyl polymers such as polyvinyl alcohol, polyvinylpyrrolidone and polyacrolein.
　水溶性ポリマの中でも、ポリカルボン酸又はその塩；ペクチン酸；寒天；ポリリンゴ酸；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；これらのエステル又はアンモニウム塩等が好ましく、ポリアクリル酸アンモニウム塩がより好ましい。 Among water-soluble polymers, polycarboxylic acid or a salt thereof; pectic acid; agar; polymalic acid; polyacrylamide; polyvinyl alcohol; polyvinyl pyrrolidone; an ester or ammonium salt thereof is preferable, and a polyacrylic acid ammonium salt is more preferable.
　水溶性ポリマの重量平均分子量は、コバルトの更に高い研磨速度を得る観点から、好ましくは５００以上、より好ましくは１，０００以上、更に好ましくは２，０００以上、特に好ましくは５，０００以上である。また、水溶性ポリマの重量平均分子量は、溶解性に優れる観点から、好ましくは１，０００，０００以下、より好ましくは５００，０００以下、更に好ましくは２００，０００以下、特に好ましくは１００，０００以下、極めて好ましくは２０，０００以下である。 The weight average molecular weight of the water-soluble polymer is preferably 500 or more, more preferably 1,000 or more, still more preferably 2,000 or more, and particularly preferably 5,000 or more, from the viewpoint of obtaining a higher polishing rate of cobalt. . Further, the weight average molecular weight of the water-soluble polymer is preferably 1,000,000 or less, more preferably 500,000 or less, still more preferably 200,000 or less, and particularly preferably 100,000 or less, from the viewpoint of excellent solubility. Very preferably 20,000 or less.
　本実施形態において、重量平均分子量として、以下の方法に基づいて、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）により測定し、標準ポリアクリル酸換算した値を使用できる。 In the present embodiment, as the weight average molecular weight, a value measured by gel permeation chromatography (GPC) based on the following method and converted to standard polyacrylic acid can be used.
［条件］
　検出器：株式会社日立製作所製、ＲＩ－モニター「Ｌ－３０００」
　インテグレーター：株式会社日立製作所製、ＧＰＣインテグレーター「Ｄ－２２００」　ポンプ：株式会社日立製作所製「Ｌ－６０００」
　デガス装置：昭和電工株式会社製「Ｓｈｏｄｅｘ　ＤＥＧＡＳ」
　カラム：日立化成株式会社製「ＧＬ－Ｒ４４０」、「ＧＬ－Ｒ４３０」及び「ＧＬ－Ｒ４２０」をこの順番で連結して使用
　溶離液：テトラヒドロフラン（ＴＨＦ）
　測定温度：２３℃
　流速：１．７５ｍＬ／ｍｉｎ
　測定時間：４５ｍｉｎ
　注入量：１０μＬ
　標準ポリアクリル酸：日立化成テクノサービス株式会社製「ＰＭＡＡ－３２」 [conditions]
Detector: manufactured by Hitachi, Ltd., RI-monitor “L-3000”
Integrator: Hitachi, Ltd., GPC integrator “D-2200” Pump: Hitachi, Ltd. “L-6000”
Degassing device: “Shodex DEGAS” manufactured by Showa Denko KK
Column: “GL-R440”, “GL-R430” and “GL-R420” manufactured by Hitachi Chemical Co., Ltd. are connected in this order. Eluent: Tetrahydrofuran (THF)
Measurement temperature: 23 ° C
Flow rate: 1.75 mL / min
Measurement time: 45 min
Injection volume: 10 μL
Standard polyacrylic acid: “PMAA-32” manufactured by Hitachi Chemical Techno Service Co., Ltd.
　ＣＭＰ用研磨液が水溶性ポリマを含有する場合、水溶性ポリマの含有量は、コバルト含有部のガルバニック腐食を更に抑制する観点から、ＣＭＰ用研磨液の総質量中、好ましくは０．００１質量％以上、より好ましくは０．００５質量％以上、更に好ましくは０．０１質量％以上である。また、水溶性ポリマの含有量は、コバルトの更に良好な研磨速度を得る観点から、ＣＭＰ用研磨液の総質量中、好ましくは１０質量％以下、より好ましくは５．０質量％以下、更に好ましくは１．０質量％以下、特に好ましくは０．５質量％以下、極めて好ましくは０．１質量％以下、非常に好ましくは０．０５質量％以下である。 When the polishing slurry for CMP contains a water-soluble polymer, the content of the water-soluble polymer is preferably 0.001% by mass in the total mass of the polishing slurry for CMP from the viewpoint of further suppressing galvanic corrosion of the cobalt-containing portion. As mentioned above, More preferably, it is 0.005 mass% or more, More preferably, it is 0.01 mass% or more. Further, the content of the water-soluble polymer is preferably 10% by mass or less, more preferably 5.0% by mass or less, and still more preferably from the total mass of the polishing slurry for CMP, from the viewpoint of obtaining a better polishing rate of cobalt. Is 1.0% by mass or less, particularly preferably 0.5% by mass or less, very preferably 0.1% by mass or less, and very preferably 0.05% by mass or less.
（水）
　ＣＭＰ用研磨液は水を含有する。水としては、特に制限されるものではないが、純水を好ましく用いることができる。水は、他の成分の残部として配合されていればよく、水の含有量に特に制限はない。 (water)
The CMP polishing liquid contains water. The water is not particularly limited, but pure water can be preferably used. There is no particular limitation on the water content as long as water is blended as the remainder of the other components.
（ＣＭＰ用研磨液のｐＨ）
　ＣＭＰ用研磨液のｐＨは、４．０以下である。ｐＨが４．０以下である場合、コバルト及び金属材料の研磨速度に優れる。ＣＭＰ用研磨液のｐＨは、好ましくは３．８以下であり、より好ましくは３．６以下であり、更に好ましくは３．５以下である。また、ＣＭＰ用研磨液のｐＨは、コバルト含有部及び金属含有部のガルバニック腐食を更に抑制する観点、及び、酸性が強いことによる取扱い難さを解消する観点から、２．０以上が好ましく、２．５以上がより好ましく、２．８以上が更に好ましく、３．０以上が特に好ましい。 (PH of polishing liquid for CMP)
The pH of the polishing liquid for CMP is 4.0 or less. When pH is 4.0 or less, it is excellent in the polishing rate of cobalt and a metal material. The pH of the polishing slurry for CMP is preferably 3.8 or less, more preferably 3.6 or less, and even more preferably 3.5 or less. The pH of the polishing slurry for CMP is preferably 2.0 or more from the viewpoint of further suppressing galvanic corrosion of the cobalt-containing part and the metal-containing part, and from the viewpoint of eliminating difficulty in handling due to strong acidity. 0.5 or more is more preferable, 2.8 or more is further preferable, and 3.0 or more is particularly preferable.
　ＣＭＰ用研磨液のｐＨは、酸成分の添加量により調整できる。また、ＣＭＰ用研磨液のｐＨは、アンモニア、水酸化ナトリウム、テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）等のアルカリ成分の添加によっても調整可能である。 The pH of the CMP polishing liquid can be adjusted by the amount of acid component added. The pH of the CMP polishing liquid can also be adjusted by adding an alkaline component such as ammonia, sodium hydroxide, tetramethylammonium hydroxide (TMAH), or the like.
　ＣＭＰ用研磨液のｐＨは、ｐＨメータ（例えば、電気化学計器株式会社製「ＰＨＬ－４０」）で測定できる。標準緩衝液（フタル酸塩ｐＨ緩衝液　ｐＨ：４．０１、中性リン酸塩ｐＨ緩衝液　ｐＨ：６．８６、ホウ酸塩ｐＨ緩衝液　ｐＨ：９．１８）を用いて３点校正した後、電極をＣＭＰ用研磨液に入れて、３ｍｉｎ以上経過して安定した後の値をＣＭＰ用研磨液のｐＨとして測定することができる。このとき、標準緩衝液とＣＭＰ用研磨液の液温は共に２５℃とする。 The pH of the polishing slurry for CMP can be measured with a pH meter (for example, “PHL-40” manufactured by Electrochemical Instrument Co., Ltd.). After three-point calibration using standard buffer (phthalate pH buffer, pH: 4.01, neutral phosphate pH buffer, pH: 6.86, borate pH buffer, pH: 9.18) The value after the electrode is put into the CMP polishing liquid and stabilized for 3 minutes or longer can be measured as the pH of the CMP polishing liquid. At this time, the temperature of the standard buffer solution and the polishing solution for CMP are both 25 ° C.
　ＣＭＰ用研磨液は、例えば、半導体デバイスにおける配線パターンの形成に適用できる。金属含有部としては、例えば、後述する導電性物質部が挙げられる。被研磨面には、後述する絶縁材料部が含まれていてもよい。コバルト含有部及び金属含有部を構成する材料については、後述する。 The CMP polishing liquid can be applied to the formation of a wiring pattern in a semiconductor device, for example. As a metal containing part, the electroconductive substance part mentioned later is mentioned, for example. The surface to be polished may include an insulating material portion described later. The materials constituting the cobalt-containing part and the metal-containing part will be described later.
＜研磨方法＞
　本実施形態に係る研磨方法は、本実施形態に係るＣＭＰ用研磨液を用いて、コバルト含有部（コバルトを含有する部分）と、コバルト以外の金属を含有する金属含有部（コバルトを含有しない部分）とを少なくとも有する被研磨面の、コバルト含有部の少なくとも一部を研磨して除去する工程を備える研磨方法である。本実施形態に係る研磨方法は、好ましくは、少なくとも一方の面にコバルト含有部及び金属含有部が形成された基板における前記コバルト含有部の余分な部分を研磨して除去する研磨方法である。本実施形態に係る研磨方法は、より具体的には、基板のコバルト含有部及び金属含有部が形成された面と、研磨定盤上の研磨パッドとの間に、本実施形態に係るＣＭＰ用研磨液を供給しながら、基板を研磨パッドに押圧した状態で、基板と研磨定盤とを相対的に動かすことによってコバルト含有部の少なくとも一部を研磨して除去する研磨方法であってもよい。 <Polishing method>
The polishing method according to the present embodiment uses a polishing liquid for CMP according to the present embodiment, and includes a cobalt-containing part (a part containing cobalt) and a metal-containing part containing a metal other than cobalt (a part not containing cobalt). ) At least a part of the cobalt-containing portion of the surface to be polished. The polishing method according to the present embodiment is preferably a polishing method in which an excess portion of the cobalt-containing portion in the substrate having the cobalt-containing portion and the metal-containing portion formed on at least one surface is polished and removed. More specifically, the polishing method according to the present embodiment is for the CMP according to the present embodiment between the surface of the substrate on which the cobalt-containing portion and the metal-containing portion are formed and the polishing pad on the polishing surface plate. A polishing method in which at least a part of the cobalt-containing portion is polished and removed by relatively moving the substrate and the polishing surface plate while the substrate is pressed against the polishing pad while supplying the polishing liquid may be used. .
　本実施形態に係る研磨方法は、半導体デバイスにおける配線層形成の一連の工程に適用できる。この場合、本実施形態に係る研磨方法は、例えば、表面に凹部及び凸部を有する絶縁材料部と、前記凹部及び前記凸部に沿って前記絶縁材料部を被覆するバリア金属部と、前記凹部を充填して前記バリア金属部を被覆する導電性物質部とを有する基板を用意する工程、前記導電性物質部を研磨して前記凸部上の前記バリア金属部を露出させる第一の研磨工程、及び、本実施形態に係るＣＭＰ用研磨液を用いて、前記第一の研磨工程で露出した前記バリア金属部を研磨して除去する第二の研磨工程を備える。前記基板は、前記バリア金属部が、コバルト含有部を有し、且つ、前記導電性物質部が、コバルト以外の金属を含有する金属含有部を有する態様であってもよい。以下、研磨方法の一例を、図１及び図２を参照しながら説明する。但し、研磨方法の用途は、下記工程に限定されない。 The polishing method according to this embodiment can be applied to a series of steps for forming a wiring layer in a semiconductor device. In this case, the polishing method according to the present embodiment includes, for example, an insulating material portion having a concave portion and a convex portion on the surface, a barrier metal portion that covers the insulating material portion along the concave portion and the convex portion, and the concave portion. Preparing a substrate having a conductive material portion that covers the barrier metal portion by filling the conductive metal portion, and a first polishing step for polishing the conductive material portion to expose the barrier metal portion on the convex portion And the 2nd grinding | polishing process of grind | polishing and removing the said barrier metal part exposed by said 1st grinding | polishing process using the polishing liquid for CMP which concerns on this embodiment is provided. The board | substrate may be the aspect in which the said barrier metal part has a cobalt containing part, and the said electroconductive substance part has a metal containing part containing metals other than cobalt. Hereinafter, an example of the polishing method will be described with reference to FIGS. 1 and 2. However, the use of the polishing method is not limited to the following steps.
　図１に示す基板は、バリア金属部としてコバルト含有部２ａを有し、導電性物質部として金属含有部３ａを有する。図１（ａ）に示すように、研磨前の基板１０は、シリコン基板（図示せず）の上に、所定パターンの凹部を有する絶縁材料部１と、絶縁材料部１の表面の凸凹に沿って絶縁材料部１を被覆するコバルト含有部２ａと、コバルト含有部２ａ上に形成された金属含有部３ａとを有する。 The substrate shown in FIG. 1 has a cobalt-containing portion 2a as a barrier metal portion and a metal-containing portion 3a as a conductive material portion. As shown in FIG. 1A, a substrate 10 before polishing is formed on a silicon substrate (not shown) along an insulating material part 1 having a predetermined pattern of concave parts and irregularities on the surface of the insulating material part 1. And a cobalt-containing part 2a that covers the insulating material part 1 and a metal-containing part 3a formed on the cobalt-containing part 2a.
　図２に示す基板は、バリア金属部２としてコバルト含有部２ａとバリア金属部２ｂとを有し、導電性物質部として金属含有部３ａを有する。図２（ａ）に示すように、研磨前の基板１１０は、シリコン基板（図示せず）の上に、所定パターンの凹部を有する絶縁材料部１と、絶縁材料部１の表面の凸凹に沿って絶縁材料部１を被覆するバリア金属部２ｂと、バリア金属部２ｂを被覆するコバルト含有部２ａと、コバルト含有部２ａ上に形成された金属含有部３ａとを有する。 The substrate shown in FIG. 2 has a cobalt-containing portion 2a and a barrier metal portion 2b as the barrier metal portion 2, and a metal-containing portion 3a as the conductive material portion. As shown in FIG. 2A, the substrate 110 before polishing is formed on a silicon substrate (not shown) along an insulating material portion 1 having a predetermined pattern of concave portions and irregularities on the surface of the insulating material portion 1. A barrier metal part 2b covering the insulating material part 1, a cobalt-containing part 2a covering the barrier metal part 2b, and a metal-containing part 3a formed on the cobalt-containing part 2a.
　絶縁材料部１を形成する材料としては、シリコン系絶縁体、有機ポリマ系絶縁体等が挙げられる。シリコン系絶縁体としては、二酸化ケイ素、フルオロシリケートグラス、オルガノシリケートグラス（例えば、トリメチルシラン、ジメトキシジメチルシラン等を出発原料として得られるオルガノシリケート）、シリコンオキシナイトライド、水素化シルセスキオキサン等のシリカ系絶縁体；シリコンカーバイド；シリコンナイトライドなどが挙げられる。また、有機ポリマ系絶縁体としては、全芳香族系低誘電率絶縁体等が挙げられる。これらの中でも、特に、二酸化ケイ素が好ましい。 Examples of the material for forming the insulating material portion 1 include a silicon-based insulator and an organic polymer-based insulator. Examples of silicon-based insulators include silicon dioxide, fluorosilicate glass, organosilicate glass (for example, organosilicate obtained from trimethylsilane, dimethoxydimethylsilane, etc.), silicon oxynitride, silsesquioxane hydride, etc. Examples thereof include silica-based insulators; silicon carbide; silicon nitride. Examples of the organic polymer insulator include wholly aromatic low dielectric constant insulators. Among these, silicon dioxide is particularly preferable.
　絶縁材料部１は、例えば、ＣＶＤ（化学気相成長）法、スピンコート法、ディップコート法、スプレー法等によって形成することができる。絶縁材料部１の具体例としては、ＬＳＩ製造工程（特に、多層配線形成工程）における層間絶縁膜等が挙げられる。 The insulating material portion 1 can be formed by, for example, a CVD (chemical vapor deposition) method, a spin coating method, a dip coating method, a spray method, or the like. Specific examples of the insulating material part 1 include an interlayer insulating film in an LSI manufacturing process (particularly, a multilayer wiring forming process).
　バリア金属部は、絶縁材料部１中へ導電性物質が拡散することを防止するため、及び、絶縁材料部１と導電性物質部との密着性向上のために形成される。コバルト含有部２ａの形成に用いられる材料としては、コバルト、コバルト合金、コバルトの酸化物、コバルト合金の酸化物等のコバルト化合物などが挙げられる。バリア金属部２ｂの形成に用いられるバリア金属としては、タンタル、窒化タンタル、タンタル合金等のタンタル化合物；チタン、窒化チタン、チタン合金等のチタン化合物；タングステン、窒化タングステン、タングステン合金等のタングステン化合物；ルテニウム、窒化ルテニウム、ルテニウム合金等のルテニウム化合物などが挙げられる。バリア金属部２ｂは、例えば、これらの一種からなる単層構造であってもよく、二種以上からなる積層構造であってもよい。すなわち、バリア金属部２ｂは、タンタル含有部、チタン含有部、タングステン含有部及びルテニウム含有部からなる群から選択される少なくとも一種を有することができる。バリア金属部は、例えば、蒸着、ＣＶＤ（化学気相成長）、スパッタ法等によって形成することができる。 The barrier metal portion is formed to prevent the conductive material from diffusing into the insulating material portion 1 and to improve the adhesion between the insulating material portion 1 and the conductive material portion. Examples of the material used for forming the cobalt-containing portion 2a include cobalt compounds such as cobalt, a cobalt alloy, a cobalt oxide, and a cobalt alloy oxide. Examples of the barrier metal used to form the barrier metal portion 2b include tantalum compounds such as tantalum, tantalum nitride, and tantalum alloys; titanium compounds such as titanium, titanium nitride, and titanium alloys; tungsten compounds such as tungsten, tungsten nitride, and tungsten alloys; Examples include ruthenium compounds such as ruthenium, ruthenium nitride, and ruthenium alloys. The barrier metal part 2b may have, for example, a single layer structure made of one of these, or a laminated structure made of two or more kinds. That is, the barrier metal part 2b can have at least one selected from the group consisting of a tantalum-containing part, a titanium-containing part, a tungsten-containing part, and a ruthenium-containing part. The barrier metal part can be formed by, for example, vapor deposition, CVD (chemical vapor deposition), sputtering, or the like.
　導電性物質部としての金属含有部３ａには、銅、銅合金、銅の酸化物、銅合金の酸化物等の、銅を主成分とする金属；タングステン、タングステン合金等の、タングステンを主成分とする金属；銀、金等の貴金属などを使用できる。中でも、銅、銅合金、銅の酸化物、銅合金の酸化物等の、銅を主成分とする金属が好ましい。「銅を主成分とする金属」とは、銅の含有量（質量）が最も大きい金属をいう。金属含有部３ａは、例えば、公知のスパッタ法、メッキ法等によって形成される。 The metal-containing portion 3a as the conductive material portion includes a copper-based metal such as copper, a copper alloy, a copper oxide, or a copper alloy oxide; a tungsten or a tungsten alloy as a main component. Metals to be used: Noble metals such as silver and gold can be used. Of these, metals mainly composed of copper, such as copper, copper alloys, copper oxides, and copper alloy oxides, are preferred. “A metal mainly composed of copper” refers to a metal having the largest copper content (mass). The metal containing part 3a is formed by, for example, a known sputtering method, plating method or the like.
　絶縁材料部１の厚さは、０．０１～２．０μｍ程度であることが好ましい。コバルト含有部２ａの厚さは、０．０１～２．５μｍ程度であることが好ましい。バリア金属部２ｂの厚さは、０．０１～２．５μｍ程度であることが好ましい。金属含有部３ａの厚さは、０．０１～２．５μｍ程度であることが好ましい。 The thickness of the insulating material part 1 is preferably about 0.01 to 2.0 μm. The thickness of the cobalt-containing portion 2a is preferably about 0.01 to 2.5 μm. The thickness of the barrier metal part 2b is preferably about 0.01 to 2.5 μm. The thickness of the metal-containing portion 3a is preferably about 0.01 to 2.5 μm.
　第一の研磨工程では、図１（ａ）に示される状態から図１（ｂ）に示される状態まで、又は、図２（ａ）に示される状態から図２（ｂ）に示される状態まで、金属含有部３ａ（すなわち、導電性物質部）を研磨する。第一の研磨工程では、例えば、導電性物質部／コバルト含有部２ａの研磨速度比が充分大きい導電性物質用のＣＭＰ用研磨液を用いて、研磨前の基板１０又は１１０の表面の導電性物質部をＣＭＰにより研磨する。これにより、凸部上の導電性物質部が除去されてコバルト含有部２ａが表面に露出し、凹部に導電性物質が残された導体パターン（すなわち、配線パターン）を有する基板２０又は１２０が得られる。導電性物質部／コバルト含有部２ａの研磨速度比が充分大きい前記導電性物質用のＣＭＰ用研磨液としては、例えば、特許第３３３７４６４号明細書に記載のＣＭＰ用研磨液を用いることができる。第一の研磨工程では、導電性物質部とともに凸部上のコバルト含有部２ａの一部が研磨されてもよい。 In the first polishing step, from the state shown in FIG. 1 (a) to the state shown in FIG. 1 (b), or from the state shown in FIG. 2 (a) to the state shown in FIG. 2 (b). Then, the metal-containing portion 3a (that is, the conductive material portion) is polished. In the first polishing step, for example, the conductivity of the surface of the substrate 10 or 110 before polishing using a polishing slurry for CMP having a sufficiently high polishing rate ratio of the conductive material part / cobalt-containing part 2a. The material part is polished by CMP. As a result, the substrate 20 or 120 having a conductor pattern (that is, a wiring pattern) in which the conductive material portion on the convex portion is removed, the cobalt-containing portion 2a is exposed on the surface, and the conductive material is left in the concave portion is obtained. It is done. As the polishing slurry for CMP for a conductive material having a sufficiently high polishing rate ratio of the conductive material portion / cobalt-containing portion 2a, for example, the polishing slurry for CMP described in Japanese Patent No. 3337464 can be used. In the first polishing step, a part of the cobalt-containing portion 2a on the convex portion may be polished together with the conductive substance portion.
　第二の研磨工程では、図１（ｂ）に示される状態から図１（ｃ）に示される状態まで、第一の研磨工程により露出したコバルト含有部２ａを本実施形態に係るＣＭＰ用研磨液を用いて研磨し、余分なコバルト含有部を除去する。 In the second polishing step, the cobalt-containing portion 2a exposed by the first polishing step from the state shown in FIG. 1B to the state shown in FIG. 1C is used as the polishing slurry for CMP according to this embodiment. Is used to remove excess cobalt-containing parts.
　また、図２に示されるように、バリア金属部２がコバルト含有部２ａとバリア金属部２ｂとを有する場合には、第二の研磨工程では、図２（ｂ）に示される状態から図２（ｃ）に示される状態まで、コバルト含有部２ａ及びバリア金属部２ｂを研磨し、余分なコバルト含有部及び余分なバリア金属部２ｂを除去する。この際、コバルト含有部２ａを本実施形態に係るＣＭＰ用研磨液により研磨して、バリア金属部２ｂが露出したら研磨を終了し、別途、バリア金属部２ｂを研磨するためのＣＭＰ用研磨液によりバリア金属部２ｂを研磨してもよい。また、一連の工程として、コバルト含有部２ａとバリア金属部２ｂとを本実施形態に係るＣＭＰ用研磨液により研磨してもよい。 As shown in FIG. 2, when the barrier metal part 2 has a cobalt-containing part 2a and a barrier metal part 2b, in the second polishing step, the state shown in FIG. The cobalt-containing part 2a and the barrier metal part 2b are polished to the state shown in (c), and the extra cobalt-containing part and the extra barrier metal part 2b are removed. At this time, the cobalt-containing portion 2a is polished with the CMP polishing liquid according to the present embodiment. When the barrier metal portion 2b is exposed, the polishing is terminated, and separately, with the CMP polishing liquid for polishing the barrier metal portion 2b. The barrier metal part 2b may be polished. Further, as a series of steps, the cobalt-containing portion 2a and the barrier metal portion 2b may be polished with the CMP polishing liquid according to the present embodiment.
　凸部のバリア金属部（コバルト含有部２ａ、又は、コバルト含有部２ａとバリア金属部２ｂ）の下の絶縁材料部１が全て露出し、凹部に配線パターンとなる導電性物質部が残され、凸部と凹部との境界にバリア金属部の断面が露出した所望のパターンを有する基板３０又は１３０が得られた時点で研磨を終了する。さらに、凹部に埋め込まれた導電性物質部がバリア金属部とともに研磨されてもよい。 The insulating material part 1 under the protruding barrier metal part (cobalt-containing part 2a or cobalt-containing part 2a and barrier metal part 2b) is completely exposed, leaving a conductive substance part that becomes a wiring pattern in the concave part, The polishing is finished when the substrate 30 or 130 having a desired pattern in which the cross section of the barrier metal part is exposed at the boundary between the convex part and the concave part is obtained. Further, the conductive material portion embedded in the recess may be polished together with the barrier metal portion.
　第二の研磨工程では、例えば、被研磨面を研磨パッド側にして基板２０又は１２０を研磨定盤の研磨パッドに押圧した状態で、研磨パッドと基板との間にＣＭＰ用研磨液を供給しながら、研磨定盤と基板２０又は１２０とを相対的に動かすことにより、被研磨面を研磨する。 In the second polishing step, for example, a CMP polishing liquid is supplied between the polishing pad and the substrate with the surface to be polished facing the polishing pad and the substrate 20 or 120 pressed against the polishing pad of the polishing surface plate. However, the surface to be polished is polished by relatively moving the polishing platen and the substrate 20 or 120.
　研磨に用いる装置としては、研磨される基板を保持するホルダと、回転数が変更可能なモータ等に接続され、且つ、研磨パッドを貼り付けた研磨定盤とを有する一般的な研磨装置を使用できる。研磨パッドとしては、一般的な不織布、発泡ポリウレタン、多孔質フッ素樹脂等が使用でき、特に制限はない。 As an apparatus used for polishing, a general polishing apparatus having a holder for holding a substrate to be polished and a polishing platen connected to a motor capable of changing the number of rotations and attached with a polishing pad is used. it can. As the polishing pad, a general nonwoven fabric, foamed polyurethane, porous fluororesin, or the like can be used, and there is no particular limitation.
　研磨条件に特に制限はないが、研磨定盤の回転速度は基板が飛び出さないように、回転数２００ｍｉｎ－１以下の低回転が好ましい。基板の研磨パッドへの押し付け圧力は、１～１００ｋＰａが好ましく、研磨速度の被研磨面内均一性及びパターンの平坦性を満足するためには、５～５０ｋＰａがより好ましい。 The polishing conditions are not particularly limited, but the rotation speed of the polishing surface plate is preferably a low rotation speed of 200 min −1 or less so that the substrate does not pop out. The pressure for pressing the substrate against the polishing pad is preferably 1 to 100 kPa, and more preferably 5 to 50 kPa in order to satisfy the in-surface uniformity of the polishing rate and the flatness of the pattern.
　研磨している間、研磨パッドと被研磨面との間には、本実施形態に係るＣＭＰ用研磨液をポンプ等で連続的に供給する。この供給量に制限はないが、研磨パッドの表面が常にＣＭＰ用研磨液で覆われていることが好ましい。研磨終了後の基板は、流水中でよく洗浄後、スピンドライ等を用いて、基板上に付着した水滴を払い落としてから乾燥させることが好ましい。 During polishing, the CMP polishing liquid according to this embodiment is continuously supplied between the polishing pad and the surface to be polished by a pump or the like. Although the supply amount is not limited, it is preferable that the surface of the polishing pad is always covered with a CMP polishing liquid. The substrate after polishing is preferably washed in running water and then dried after removing water droplets adhering to the substrate using spin drying or the like.
　研磨パッドの表面状態を常に同一にしてＣＭＰを行うために、研磨の前に研磨パッドのコンディショニング工程を入れることが好ましい。例えば、ダイヤモンド粒子のついたドレッサを用いて、少なくとも水を含む液で研磨パッドのコンディショニングを行う。続いて本実施形態に係る研磨方法を実施した後、基板洗浄工程を行うことが好ましい。 In order to perform CMP with the surface state of the polishing pad always the same, it is preferable to perform a conditioning step of the polishing pad before polishing. For example, using a dresser with diamond particles, the polishing pad is conditioned with a liquid containing at least water. Subsequently, it is preferable to perform a substrate cleaning step after performing the polishing method according to the present embodiment.
　このようにして形成された配線パターンの上に、第二層目の絶縁材料部、バリア金属部及び導電性物質部を更に形成した後、研磨して半導体基板全面に亘って平滑な面とすることができる。この工程を所定数繰り返すことにより、所望の配線層数を有する半導体デバイスを製造できる。 On the wiring pattern thus formed, after further forming an insulating material part, a barrier metal part and a conductive substance part of the second layer, it is polished to make a smooth surface over the entire surface of the semiconductor substrate. be able to. By repeating this step a predetermined number, a semiconductor device having a desired number of wiring layers can be manufactured.
　本実施形態に係るＣＭＰ用研磨液は、上記のような半導体基板の研磨だけでなく、磁気ヘッド等の基板を研磨するためにも使用できる。 The CMP polishing liquid according to this embodiment can be used not only for polishing a semiconductor substrate as described above but also for polishing a substrate such as a magnetic head.
　以下、実施例により本発明を更に具体的に説明するが、本発明の技術思想を逸脱しない限り、本発明はこれらの実施例に限定されるものではない。例えば、ＣＭＰ用研磨液の材料の種類及びその配合比率は、本実施例に記載の種類及び配合比率以外の種類及び配合比率でも構わない。また、研磨対象の組成及び構造も、本実施例に記載の組成及び構造以外の組成及び構造でも構わない。 Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples unless departing from the technical idea of the present invention. For example, the type of the polishing slurry for CMP and the mixing ratio thereof may be other types and mixing ratios than the types and mixing ratios described in the present embodiment. The composition and structure to be polished may also be a composition and structure other than the composition and structure described in this example.
＜ＣＭＰ用研磨液の作製方法＞
　表１に示す各成分を用いてＣＭＰ用研磨液を下記の方法で作製した。 <Preparation method of polishing liquid for CMP>
Using the components shown in Table 1, a CMP polishing liquid was prepared by the following method.
（実施例１～６及び比較例１～２）
　表１に示す種類の金属防食剤と、３－メトキシ－３－メチル－１－ブタノール（有機溶媒）と、ポリアクリル酸アンモニウム塩（水溶性ポリマ、重量平均分子量８，０００）と、コロイダルシリカ（砥粒（研磨粒子）、平均二次粒径６０ｎｍ）とを容器に入れた。さらに、超純水を注いだ後、撹拌により混合して、砥粒を除く全成分を溶解させた。酸化剤として過酸化水素水（３０質量％水溶液）を添加した後、超純水を加えて全体を１００質量部とし、ＣＭＰ用研磨液を得た。 (Examples 1 to 6 and Comparative Examples 1 and 2)
A metal anticorrosive of the type shown in Table 1, 3-methoxy-3-methyl-1-butanol (organic solvent), ammonium polyacrylate (water-soluble polymer, weight average molecular weight 8,000), colloidal silica ( Abrasive grains (abrasive particles) and an average secondary particle size of 60 nm were placed in a container. Furthermore, after pouring ultrapure water, it was mixed by stirring to dissolve all components except the abrasive grains. After adding hydrogen peroxide water (30% by mass aqueous solution) as an oxidizing agent, ultrapure water was added to make the whole 100 parts by mass, and a polishing liquid for CMP was obtained.
　各成分の含有量は表１に示したとおりである。なお、砥粒の含有量は「シリカ粒子」の質量％として示し、酸化剤の含有量は「過酸化水素」の質量％として示した。コロイダルシリカの平均粒径（平均二次粒径）と、ポリアクリル酸アンモニウム塩の重量平均分子量は、上述の方法に従って測定した。 The content of each component is as shown in Table 1. The content of abrasive grains is shown as mass% of “silica particles”, and the content of oxidizing agent is shown as mass% of “hydrogen peroxide”. The average particle diameter (average secondary particle diameter) of colloidal silica and the weight average molecular weight of polyacrylic acid ammonium salt were measured according to the above-mentioned method.
＜ｐＨの測定方法＞
　ＣＭＰ用研磨液のｐＨを下記に従って測定した。
　測定温度：２５℃
　測定器：電気化学計器株式会社製「ＰＨＬ－４０」
　測定方法：標準緩衝液（フタル酸塩ｐＨ緩衝液　ｐＨ：４．０１（２５℃）、中性リン酸塩ｐＨ緩衝液　ｐＨ：６．８６（２５℃）、ホウ酸塩ｐＨ緩衝液　ｐＨ：９．１８（２５℃）を用いて３点校正した後、電極をＣＭＰ用研磨液に入れて、３ｍｉｎ以上経過して安定した後の値を測定した。結果を表１に示した。 <Measurement method of pH>
The pH of the CMP polishing liquid was measured according to the following.
Measurement temperature: 25 ° C
Measuring instrument: “PHL-40” manufactured by Electrochemical Instruments Co., Ltd.
Measurement method: standard buffer (phthalate pH buffer solution pH: 4.01 (25 ° C.), neutral phosphate pH buffer solution pH: 6.86 (25 ° C.), borate pH buffer solution pH: 9 After calibrating three points using .18 (25 ° C.), the electrode was placed in a polishing slurry for CMP, and the value after 3 minutes had elapsed and stabilized was measured, and the results are shown in Table 1.
＜コバルトに対するエッチング量評価＞
　１２インチのシリコン基板上に厚さ２００ｎｍのコバルト層を形成したブランケット基板（ａ）を用意した。上記ブランケット基板（ａ）を２０ｍｍ角のチップに切り出して評価用チップ（ｂ）を用意した。 <Etching amount evaluation for cobalt>
A blanket substrate (a) in which a cobalt layer having a thickness of 200 nm was formed on a 12-inch silicon substrate was prepared. The blanket substrate (a) was cut into 20 mm square chips to prepare evaluation chips (b).
　前記各研磨剤（ＣＭＰ用研磨液）１００ｇを入れたビーカの中に前記評価用チップ（ｂ）をそれぞれ入れ、６０℃の恒温槽に１分間浸漬した。浸漬後の評価チップ（ｂ）を取り出し、純水で充分に洗浄した後、窒素ガスを吹きかけてチップ上の水分を乾燥させた。乾燥後の評価用チップ（ｂ）の抵抗を抵抗率計にて測定し、下記式（１）にて浸漬後のコバルト層の厚さに換算した。 The evaluation chip (b) was put in a beaker containing 100 g of each polishing agent (CMP polishing liquid) and immersed in a thermostat at 60 ° C. for 1 minute. The evaluation chip (b) after immersion was taken out and thoroughly washed with pure water, and then nitrogen gas was blown to dry the water on the chip. The resistance of the evaluation chip (b) after drying was measured with a resistivity meter, and converted into the thickness of the cobalt layer after immersion by the following formula (1).
　ブランケット基板（ａ）の各厚さにそれぞれ対応する抵抗値の情報から検量線を得て、下記式（１）より、コバルト層の厚さを求めた。
　浸漬後のコバルト層の厚さ［ｎｍ］＝１０４．５×（評価用チップ（ｂ）の抵抗値［ｍΩ］／１０００）－０．８９３　・・・（１） A calibration curve was obtained from information on resistance values corresponding to the thicknesses of the blanket substrate (a), and the thickness of the cobalt layer was determined from the following formula (1).
Thickness [nm] of cobalt layer after immersion = 104.5 × (resistance value [mΩ] / 1000 for evaluation chip (b)) − 0.893 (1)
　そして、得られた浸漬後のコバルト層の厚さと、浸漬前のコバルト層の厚さとから、下記式（２）より、コバルト層のエッチング速度を求めた。
　コバルト層のエッチング速度（Ｃｏ－ＥＲ）［ｎｍ／ｍｉｎ］＝（浸漬前のコバルト層の厚さ［ｎｍ］－浸漬後のコバルト層の厚さ［ｎｍ］）／１分　・・・（２） And the etching rate of the cobalt layer was calculated | required from following formula (2) from the thickness of the obtained cobalt layer after immersion, and the thickness of the cobalt layer before immersion.
Etching rate of cobalt layer (Co-ER) [nm / min] = (thickness of cobalt layer before immersion [nm] −thickness of cobalt layer after immersion [nm]) / 1 minute (2)
　上記で得られた各研磨剤について、コバルトのエッチング速度を求めた。この結果を表１に示した。 The etching rate of cobalt was determined for each abrasive obtained above. The results are shown in Table 1.
＜コバルトに対する研磨速度評価＞
　上記で得られた各研磨剤（ＣＭＰ用研磨液）を用いて下記条件で上記ブランケット基板（ａ）を研磨及び洗浄したときの研磨速度（Ｃｏ－ＲＲ）［ｎｍ／ｍｉｎ］を求めた。研磨速度は、研磨時間と、コバルト層の研磨前後の厚さの差とに基づき求めた。この結果を表１に併せて示した。 <Polishing rate evaluation for cobalt>
The polishing rate (Co-RR) [nm / min] when the blanket substrate (a) was polished and washed under the following conditions using the respective abrasives (CMP polishing liquid) obtained above was determined. The polishing rate was determined based on the polishing time and the difference in thickness before and after the polishing of the cobalt layer. The results are also shown in Table 1.
（研磨条件）
　研磨装置：片面金属膜用研磨機（アプライドマテリアルズ社製「Ｒｅｆｌｅｘｉｏｎ　ＬＫ」）
　研磨パッド：発泡ポリウレタン樹脂製の研磨パッド
　定盤回転数：９３ｍｉｎ－１
　研磨ヘッド回転数：８７ｍｉｎ－１
　研磨圧力：１０．３ｋＰａ（１．５ｐｓｉ）
　ＣＭＰ用研磨液の供給量：３００ｍＬ／ｍｉｎ
　研磨時間：０．５ｍｉｎ (Polishing conditions)
Polishing device: Polishing machine for single-sided metal film ("Reflexion LK" manufactured by Applied Materials)
Polishing pad: Polishing pad made of polyurethane foam resin Platen rotation speed: 93 min −1
Polishing head rotation speed: 87 min −1
Polishing pressure: 10.3 kPa (1.5 psi)
Supply amount of polishing liquid for CMP: 300 mL / min
Polishing time: 0.5 min
（洗浄条件（被研磨基板の洗浄））
　前記で研磨した被研磨基板の被研磨面にスポンジブラシ（ポリビニルアルコール系樹脂製）を押し付けた後、蒸留水を被研磨基板に供給しながら被研磨基板とスポンジブラシとを回転させ、１ｍｉｎ洗浄した。次に、スポンジブラシを取り除いた後、被研磨基板の被研磨面に蒸留水を１分間供給した。最後に、被研磨基板を高速で回転させて蒸留水を弾き飛ばして被研磨基板を乾燥した。 (Cleaning conditions (cleaning of the substrate to be polished))
After pressing a sponge brush (made of polyvinyl alcohol resin) onto the surface to be polished of the substrate polished above, the substrate to be polished and the sponge brush were rotated while supplying distilled water to the substrate to be cleaned, and washed for 1 min. . Next, after removing the sponge brush, distilled water was supplied to the surface to be polished of the substrate to be polished for 1 minute. Finally, the substrate to be polished was rotated at a high speed to blow off distilled water and dry the substrate to be polished.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１から明らかであるように、比較例１のように金属防食剤を用いない場合、コバルト研磨速度は大きいが、エッチング速度も大きくなる。また、比較例２のようにアゾール類の無機酸塩が用いられる場合には、コバルト研磨速度及びエッチング速度ともに大きくなる。
　これに対し、実施例１～６では、特定の２種類の金属防食剤を用いることで、６０℃の条件下でもコバルトのエッチング速度が顕著に抑制されつつ、コバルトを適度な研磨速度で研磨できることがわかった。 As apparent from Table 1, when no metal anticorrosive is used as in Comparative Example 1, the cobalt polishing rate is high, but the etching rate is also high. Further, when an azole inorganic salt is used as in Comparative Example 2, both the cobalt polishing rate and the etching rate are increased.
On the other hand, in Examples 1 to 6, by using two specific types of metal anticorrosives, cobalt can be polished at an appropriate polishing rate while the cobalt etching rate is remarkably suppressed even at 60 ° C. I understood.
　本発明の実施形態であるＣＭＰ用研磨液及び研磨方法によれば、従来のＣＭＰ用研磨液を用いた場合と比較して、コバルト含有部の研磨速度を維持しつつ、コバルトのエッチングを抑制できる。 According to the CMP polishing liquid and the polishing method according to the embodiment of the present invention, it is possible to suppress the etching of cobalt while maintaining the polishing rate of the cobalt-containing portion as compared with the case of using the conventional CMP polishing liquid. .
　１…絶縁材料部、２…バリア金属部、２ａ…コバルト含有部、２ｂ…バリア金属部、３…導電性物質部、３ａ…コバルト以外の金属を含有する金属含有部、１０，１１０，２１０…研磨前の基板、２０，１２０，２２０…第一の研磨工程後の基板、３０，１３０，２３０…第二の研磨工程後の基板。 DESCRIPTION OF SYMBOLS 1 ... Insulating material part, 2 ... Barrier metal part, 2a ... Cobalt containing part, 2b ... Barrier metal part, 3 ... Conductive substance part, 3a ... Metal containing part containing metals other than cobalt 10, 110, 210 ... Substrate before polishing, 20, 120, 220... Substrate after first polishing step, 30, 130, 230... Substrate after second polishing step.

Claims (10)

  1. 　コバルト含有部と、コバルト以外の金属を含有する金属含有部とを少なくとも有する被研磨面の研磨に用いられるＣＭＰ用研磨液であって、
    　研磨粒子、２種類の金属防食剤、及び、水を含有し、
    　ｐＨが４．０以下であり、
    　前記２種類の金属防食剤がともにアゾール類（無機酸の塩を除く）である、ＣＭＰ用研磨液。     A polishing slurry for CMP used for polishing a surface to be polished having at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt,
    Containing abrasive particles, two metal anticorrosives, and water,
    pH is 4.0 or less,
    A polishing liquid for CMP, wherein both of the two types of metal anticorrosives are azoles (excluding inorganic acid salts).
  2. 　水溶性ポリマを更に含有する、請求項１に記載のＣＭＰ用研磨液。 The polishing slurry for CMP according to claim 1, further comprising a water-soluble polymer.
  3. 　前記研磨粒子が、シリカ粒子、アルミナ粒子、セリア粒子、チタニア粒子、ジルコニア粒子、ゲルマニア粒子及びこれらの変性物からなる群から選択される少なくとも一種を含む、請求項１又は２に記載のＣＭＰ用研磨液。 The polishing for CMP according to claim 1 or 2, wherein the abrasive particles include at least one selected from the group consisting of silica particles, alumina particles, ceria particles, titania particles, zirconia particles, germania particles, and modified products thereof. liquid.
  4. 　金属酸化剤を更に含有する、請求項１～３のいずれか一項に記載のＣＭＰ用研磨液。 The polishing slurry for CMP according to any one of claims 1 to 3, further comprising a metal oxidizing agent.
  5. 　有機溶媒を更に含有する、請求項１～４のいずれか一項に記載のＣＭＰ用研磨液。 The polishing slurry for CMP according to any one of claims 1 to 4, further comprising an organic solvent.
  6. 　請求項１～５のいずれか一項に記載のＣＭＰ用研磨液を用いて、コバルト含有部と、コバルト以外の金属を含有する金属含有部とを少なくとも有する被研磨面の、前記コバルト含有部の少なくとも一部を研磨して除去する、研磨方法。 The polishing liquid for CMP according to any one of claims 1 to 5, wherein the cobalt-containing portion of the surface to be polished has at least a cobalt-containing portion and a metal-containing portion containing a metal other than cobalt. A polishing method in which at least a portion is polished and removed.
  7. 　表面に凹部及び凸部を有する絶縁材料部と、前記凹部及び前記凸部に沿って前記絶縁材料部を被覆するバリア金属部と、前記凹部を充填して前記バリア金属部を被覆する導電性物質部とを有する基板を用意する工程、
    　前記導電性物質部を研磨して前記凸部上の前記バリア金属部を露出させる第一の研磨工程、及び、
    　請求項１～５のいずれか一項に記載のＣＭＰ用研磨液を用いて、前記第一の研磨工程で露出した前記バリア金属部を研磨して除去する第二の研磨工程を備え、
    　前記バリア金属部が、コバルト含有部を有し、
    　前記導電性物質部が、コバルト以外の金属を含有する金属含有部を有する、研磨方法。     An insulating material part having a concave part and a convex part on the surface, a barrier metal part covering the insulating material part along the concave part and the convex part, and a conductive substance filling the concave part and covering the barrier metal part Preparing a substrate having a portion,
    A first polishing step of polishing the conductive material portion to expose the barrier metal portion on the convex portion; and
    A second polishing step for polishing and removing the barrier metal portion exposed in the first polishing step using the CMP polishing liquid according to any one of claims 1 to 5,
    The barrier metal part has a cobalt-containing part;
    The grinding | polishing method in which the said electroconductive substance part has a metal containing part containing metals other than cobalt.
  8. 　前記絶縁材料部がシリコン系絶縁体及び有機ポリマ系絶縁体からなる群から選択される少なくとも一種を含有する、請求項７に記載の研磨方法。 The polishing method according to claim 7, wherein the insulating material portion contains at least one selected from the group consisting of a silicon-based insulator and an organic polymer-based insulator.
  9. 　前記導電性物質部が銅を主成分とする、請求項７又は８に記載の研磨方法。 The polishing method according to claim 7 or 8, wherein the conductive material portion contains copper as a main component.
  10. 　前記バリア金属部が、前記コバルト含有部と、タンタル含有部、チタン含有部、タングステン含有部及びルテニウム含有部からなる群から選択される少なくとも一種とを有する、請求項７～９のいずれか一項に記載の研磨方法。 The barrier metal part has the cobalt-containing part and at least one selected from the group consisting of a tantalum-containing part, a titanium-containing part, a tungsten-containing part, and a ruthenium-containing part. The polishing method according to 1.
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JP2011091248A (en) * 2009-10-23 2011-05-06 Hitachi Chem Co Ltd Polishing liquid for cobalt, and substrate polishing method using the same
JP2012182158A (en) * 2011-02-08 2012-09-20 Hitachi Chem Co Ltd Polishing liquid and method for polishing substrate using polishing liquid
JP2013042123A (en) * 2011-07-20 2013-02-28 Hitachi Chemical Co Ltd Abrasive and method for polishing substrate

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011091248A (en) * 2009-10-23 2011-05-06 Hitachi Chem Co Ltd Polishing liquid for cobalt, and substrate polishing method using the same
JP2012182158A (en) * 2011-02-08 2012-09-20 Hitachi Chem Co Ltd Polishing liquid and method for polishing substrate using polishing liquid
JP2013042123A (en) * 2011-07-20 2013-02-28 Hitachi Chemical Co Ltd Abrasive and method for polishing substrate

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