WO2014065029A1 - Polishing solution for chemical mechanical polishing (cmp), stock solution, and polishing method - Google Patents

Polishing solution for chemical mechanical polishing (cmp), stock solution, and polishing method Download PDF

Info

Publication number
WO2014065029A1
WO2014065029A1 PCT/JP2013/074132 JP2013074132W WO2014065029A1 WO 2014065029 A1 WO2014065029 A1 WO 2014065029A1 JP 2013074132 W JP2013074132 W JP 2013074132W WO 2014065029 A1 WO2014065029 A1 WO 2014065029A1
Authority
WO
WIPO (PCT)
Prior art keywords
polishing
cmp
liquid
aluminum
abrasive grains
Prior art date
Application number
PCT/JP2013/074132
Other languages
French (fr)
Japanese (ja)
Inventor
井上　恵介
小野　裕
大祐 保坂
Original Assignee
日立化成株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日立化成株式会社 filed Critical 日立化成株式会社
Publication of WO2014065029A1 publication Critical patent/WO2014065029A1/en

Links

Images

Classifications

    • 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
    • B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
    • B24B37/042—Lapping machines or devices; Accessories designed for working plane surfaces operating processes therefor
    • B24B37/044—Lapping machines or devices; Accessories designed for working plane surfaces operating processes therefor characterised by the composition of the lapping agent
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09G—POLISHING COMPOSITIONS; SKI WAXES
    • C09G1/00—Polishing compositions
    • C09G1/02—Polishing compositions containing abrasives or grinding agents
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/14—Anti-slip materials; Abrasives
    • C09K3/1436—Composite particles, e.g. coated particles
    • 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
    • C09K3/1454—Abrasive powders, suspensions and pastes for polishing
    • C09K3/1463—Aqueous liquid suspensions

Definitions

  • the present invention relates to a CMP polishing liquid for use in chemical mechanical polishing (CMP), a storage liquid for obtaining the polishing liquid, and a polishing method using these.
  • CMP chemical mechanical polishing
  • Stainless steel which is an alloy of iron and other metals (chromium, nickel, etc.), is used as the material for the chassis of railway vehicles, aircraft parts, automobile parts, electronic equipment, etc., because of its excellent corrosion resistance or strength. It is often done. However, the density of stainless steel is about 7.64 to 8.06 g / cm 3 , and stainless steel has a limit to meet the recent demand for weight reduction of materials.
  • Aluminum-based materials having a density of about 2.64 to 2.82 g / cm 3 (about 1/3 of stainless steel) are attracting attention.
  • Aluminum materials include pure aluminum (1000 series), Al—Cu (2000 series), Al—Mn (3000 series), Al—Si (4000 series), Al—Mg (5000 series), Al—Mg—Si. (6000 series), Al—Zn—Mg (7000 series) and the like are known.
  • the strength of pure aluminum (1000-based) is slightly low, but the aluminum alloy is excellent in workability and the like in addition to being excellent in corrosion resistance and strength like stainless steel.
  • most materials using stainless steel have a slightly blackish silver color derived from chrome, whereas materials using aluminum alloys can be white silvery in appearance. Can be bright and beautiful.
  • the method for polishing an aluminum-based material include mechanical polishing and chemical polishing.
  • the surface of aluminum-based materials finished by mechanical polishing often has a metallic luster that has disappeared (for example, a pattern with no directionality or a pattern with directionality). Further, even when buffing that can be relatively smoothed is used, it cannot be said that a sufficiently smooth surface is obtained.
  • There is a method for obtaining a certain level of metallic luster in mechanical polishing but there is a limit to the gloss that can be obtained by mechanical polishing. As described above, when a sufficiently smooth surface is required in the polishing of an aluminum-based material, it is difficult to satisfy the requirement by the conventional mechanical polishing.
  • chemical polishing may be used to obtain a smooth aluminum-based material surface. Since the smoothing process using only chemical polishing takes time, the surface subjected to the mechanical polishing process may be subjected to a chemical polishing process.
  • CMP is polishing using both mechanical action and chemical action. Specifically, while softening or dissolving the aluminum-based material by a chemical action, at the same time, the surface of the aluminum-based material is removed by a mechanical action due to friction between the aluminum-based material and abrasive grains to smooth the surface. There is a case.
  • a method of adding acetic acid to improve the gloss of the surface to be polished is also known.
  • a method using a liquid containing 50 to 80% by mass of phosphoric acid, 5 to 20% by mass of nitric acid, and 3 to 20% by mass of acetic acid is known (see, for example, Patent Document 1 below).
  • organic substances such as oxalic acid and citric acid are also known as substances added to improve the gloss of the surface to be polished (for example, see Non-Patent Document 1 below).
  • polishing of an aluminum-based material by CMP has also been studied.
  • polishing liquids for CMP for polishing aluminum-based materials are known (for example, see Patent Document 3 below), but the types are not abundant.
  • Patent Document 3 describes a CMP polishing liquid containing alumina particles as abrasive grains.
  • the aluminum-based material is soft, the surface roughness tends to increase when CMP is performed using a CMP polishing liquid containing alumina particles. This increase in surface roughness significantly reduces the yield.
  • softer colloidal silica is effective for surface roughness as abrasive grains (see, for example, Patent Documents 4 and 5 below).
  • the present invention has been made in view of the above problems, and provides a polishing liquid for CMP capable of smoothly polishing a substrate containing an aluminum-based material, a storage liquid for obtaining the polishing liquid, and a polishing method using these.
  • the purpose is to provide.
  • the present inventor has found that the surface roughness is reduced when the circularity value obtained by analyzing the particle shape of the abrasive grains obtained by observation with a scanning electron microscope (SEM) is below a specific value.
  • SEM scanning electron microscope
  • the CMP polishing liquid according to the present invention is a CMP polishing liquid for polishing a substrate containing an aluminum-based material, and contains abrasive grains, an oxidizing agent, and a liquid medium, and the circularity of the abrasive grains is 0. 90 or less, and the pH of the polishing slurry for CMP is 11.5 or less.
  • a substrate containing an aluminum-based material can be polished smoothly.
  • the aluminum alloy surface can be equally flatly polished on the aluminum alloy surface and the portion containing different elements in addition to aluminum.
  • the substrate can be polished smoothly.
  • the present inventors have found that a higher polishing rate is better in order to reduce the surface roughness in the shortest possible time.
  • the high polishing rate also has the effect of shortening the overall work time (improving throughput).
  • the present inventors are able to increase the polishing rate while having a good surface roughness, that is, to achieve both the surface roughness and the polishing rate, regardless of the conventional abrasive grains. I found it difficult to trade off.
  • the inventors have a tendency that the surface roughness tends to deteriorate when the grain size of the abrasive grains is increased in order to increase the polishing rate. It has been found that when the grain size of the abrasive grains is reduced, the polishing rate tends to decrease although the surface roughness is improved.
  • the present inventors It has been found that the polishing rate increases remarkably as the surface roughness decreases.
  • a substrate containing an aluminum-based material can be polished at high speed and smoothly.
  • a substrate containing an aluminum alloy can be polished at high speed and smoothly.
  • a substrate containing an aluminum-based material such as an aluminum alloy can be polished at high speed, and a substrate having a smooth surface can be obtained simply and efficiently.
  • the sphericity of the abrasive grains is preferably 0.30 or more and 0.80 or less. Thereby, it becomes easy to polish the substrate containing the aluminum-based material at high speed and smoothly.
  • the pH of the CMP polishing liquid is preferably 7.0 or more. Thereby, it becomes easy to polish the substrate containing the aluminum-based material at high speed and smoothly.
  • the storage liquid according to the present invention is a storage liquid for obtaining the CMP polishing liquid, and the CMP polishing liquid can be obtained by diluting with a liquid medium. According to such a storage liquid, the cost related to storage, transportation, storage, etc. of the polishing liquid for CMP can be reduced.
  • An embodiment of the polishing method according to the present invention includes a step of polishing a substrate containing an aluminum-based material using the CMP polishing liquid. According to such a polishing method, a substrate containing an aluminum-based material can be polished smoothly at high speed, and a substrate containing an aluminum-based material can be polished easily and efficiently.
  • Another aspect of the polishing method according to the present invention includes a step of polishing a substrate containing an aluminum-based material using a CMP polishing liquid obtained by diluting the storage liquid with a liquid medium.
  • a polishing method the cost for storing, transporting, storing, etc. of the polishing liquid for CMP can be suppressed, so that the overall manufacturing cost can be reduced and the substrate containing the aluminum-based material can be polished smoothly at high speed.
  • the present invention it is possible to provide a CMP polishing liquid capable of smoothly polishing a substrate containing an aluminum-based material, a storage liquid for obtaining the polishing liquid, and a polishing method using these. Further, according to the present invention, it is possible to provide a polishing liquid for CMP capable of polishing a substrate containing an aluminum-based material smoothly and at high speed, a storage liquid for obtaining the polishing liquid, and a polishing method using these. Furthermore, according to this invention, the selection method of the abrasive grain which can perform the grinding
  • a substrate containing an aluminum alloy can be polished at high speed and smoothly.
  • a substrate containing an aluminum-based material such as an aluminum alloy can be polished at high speed, and a substrate having a smooth surface can be obtained simply and efficiently.
  • a polishing liquid for CMP and a storage liquid to polishing a substrate containing an aluminum-based material is provided.
  • application of a polishing liquid for CMP and a storage liquid to polishing a substrate containing an aluminum alloy is provided.
  • Applications for polishing liquids and storage liquids are provided.
  • the CMP polishing liquid (aluminum polishing liquid) according to this embodiment is a polishing liquid for polishing a substrate containing an aluminum-based material.
  • the CMP polishing liquid according to the present embodiment includes abrasive grains, an oxidizing agent, and a liquid medium (for example, water), the circularity of the abrasive grains is 0.90 or less, and the pH of the CMP polishing liquid is 11.5. It is characterized by the following.
  • the CMP polishing liquid according to the present embodiment includes abrasive grains.
  • abrasive grains silica (silicon oxide) such as fumed silica and colloidal silica, alumina (aluminum oxide) such as fumed alumina and colloidal alumina, ceria (cerium oxide) such as calcined ceria and colloidal ceria, zirconia (zirconium oxide) ) And the like.
  • silica is preferable and colloidal silica is more preferable from the viewpoint of easily achieving both a high polishing rate for an aluminum-based material and smoothing of the surface.
  • the CMP polishing liquid may contain one kind or two or more kinds of abrasive grains.
  • silica is preferably an essential component
  • colloidal silica is more preferably an essential component.
  • the circularity of the abrasive grains is 0.90 or less.
  • the circularity is preferably less than 0.90, more preferably 0.87 or less, and still more preferably 0.85 or less.
  • the circularity is preferably 0.83 or less, and more preferably 0.80 or less.
  • the circularity of at least one abrasive grain may be 0.90 or less.
  • abrasive grains having a circularity of 0.90 or less may be used, and abrasive grains having a circularity of 0.90 or less and a circularity of 0.90. More abrasive grains may be used in combination.
  • the content of abrasive grains having a circularity of 0.90 or less is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and 90% by mass based on the total mass of the abrasive grains. % Or more is particularly preferable, 95% by mass or more is very preferable, and 98% by mass or more is very preferable.
  • the circularity of the abrasive grains is an index reflecting the particle shape (that is, the uneven state of the particle surface). The closer the circularity is to 1.00, the closer the particle projection diagram is to a perfect circle without irregularities. When the circularity exceeds 0.90, the abrasive has a state close to a true sphere.
  • the circularity of the abrasive grains can be determined, for example, by the following procedure.
  • a photograph projection view (particle projection view) containing a plurality of particles is obtained by photographing with a scanning electron microscope. Select any 80 particles in the photographic projection.
  • the ratio (L ′ / L) of the circumference (outer circumference) L ′ of a perfect circle having an area equal to the area of the particles in the photographic projection to the circumference L of the photographic projection is obtained for each particle (for example, Ratio (L '/ L) of the circumference L' of the perfect circle 1a (Fig. 1 (b)) having an area equal to the area S of the measurement particle 1 to the circumference L of the measurement particle 1 shown in Fig. 1 (a) Seeking).
  • Ratio (L '/ L) of the circumference L' of the perfect circle 1a Fig. 1 (b)
  • the sphericity of the abrasive grains is preferably 0.30 or more, more preferably 0.35 or more, from the viewpoint of easily increasing the polishing rate for the aluminum-based material and easily obtaining a smooth aluminum-based material surface. .40 or more is more preferable, 0.45 or more is particularly preferable, and 0.50 or more is very preferable.
  • the sphericity of the abrasive grains is preferably 0.80 or less, and more preferably 0.77 or less, from the viewpoint of increasing the polishing rate for the aluminum-based material and easily obtaining a smooth aluminum-based material surface.
  • the sphericity is preferably 0.75 or less, and more preferably 0.70 or less, from the viewpoint of further improving the polishing rate.
  • the abrasive grains When the sphericity is less than 0.30, the abrasive grains have an elongated shape. When the sphericity exceeds 0.80, the abrasive has a state close to a sphere. In the CMP polishing liquid according to this embodiment, it is preferable that at least one type of abrasive grains having a circularity of 0.90 or less has the sphericity.
  • the sphericity of the abrasive grains is the length of the minor axis perpendicular to the major axis with respect to the maximum diameter of the major axis having the maximum diameter of the particles in the photographic projection drawing obtained by photographing with a scanning electron microscope. Mean ratio (length of minor axis / maximum diameter).
  • the sphericity of the abrasive grains can be determined, for example, by the following procedure.
  • a photograph projection view (particle projection view) containing a plurality of particles is obtained by photographing with a scanning electron microscope. Select any 80 particles in the photographic projection. When the selected particle has a shape as shown in FIG.
  • the rectangle (circumscribed rectangle) 2 circumscribing the measurement particle 1 is guided so that the length DL of the major axis of the rectangle 2 becomes the longest.
  • the ratio of the length DS to the length DL is determined for each particle. Calculate the average of the ratio DS / DL of 80 particles as “sphericity”.
  • the present inventor considers as follows. That is, when the sphericity of the abrasive grains is 0.30 or more and 0.80 or less, it is considered that the contact area between the surface to be polished and the abrasive grains is increased, friction is easily generated, and the polishing rate is improved. On the other hand, when the sphericity exceeds 0.80, the contact area between the surface to be polished and the abrasive grains decreases, and it is assumed that the polishing rate decreases.
  • the particle shape is close to a rod shape, and the direction of movement of the abrasive grains is greatly limited as compared with the case where the sphericity is 0.30 or more. It is assumed that the speed will decrease.
  • the primary particle size of the abrasive grains is preferably 5.0 nm or more, more preferably 10.0 nm or more, from the viewpoint of easily increasing the polishing rate for the aluminum material and obtaining a smooth surface of the aluminum material. More preferably, it is 0.0 nm or more.
  • the primary particle size of the abrasive grains is preferably 150.0 nm or less, more preferably 120.0 nm or less, still more preferably 100.0 nm or less, and particularly preferably 70.0 nm or less, from the viewpoint of improving the surface smoothness more efficiently. 50.0 nm or less is very preferable.
  • the primary particle size of the abrasive grains is the maximum diameter of the major axis having the maximum diameter of the particle and the length of the minor axis perpendicular to the major axis of the particle in the photographic projection obtained by photographing with a scanning electron microscope. It means the average value of the square root of the product (biaxial average particle diameter).
  • the primary particle size of the abrasive grains can be determined, for example, by the following procedure.
  • a photograph projection view (particle projection view) containing a plurality of particles is obtained by photographing with a scanning electron microscope. Select any 80 particles in the photographic projection. When the selected particle has a shape as shown in FIG.
  • the rectangle (circumscribed rectangle) 2 circumscribing the measurement particle 1 is guided so that the length DL of the major axis of the rectangle 2 becomes the longest.
  • the biaxial average particle diameter ( ⁇ (DL ⁇ DS)) is determined for each particle based on the length DL of the major axis of the rectangle 2 and the length DS of the minor axis orthogonal to the major axis.
  • the average of the biaxial average particle diameters of 80 particles is calculated as “primary particle diameter”.
  • the content of abrasive grains in the polishing liquid for CMP is the total mass of the polishing liquid for CMP from the viewpoint of easily achieving a polishing speed that is sufficiently different from the polishing speed when the polishing liquid does not contain abrasive grains.
  • it is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 3% by mass or more, particularly preferably 4% by mass or more, and extremely preferably 5% by mass or more.
  • the content of the abrasive grains in the CMP polishing liquid is preferably 30% by mass or less, preferably 25% by mass, based on the total mass of the CMP polishing liquid, from the viewpoint of easily obtaining an effect of improving the polishing rate according to the content. The following is more preferable, 20% by mass or less is further preferable, 17.5% by mass or less is particularly preferable, and 15% by mass or less is extremely preferable. From the above viewpoint, the content of abrasive grains is preferably 1 to 30% by mass.
  • the polishing slurry for CMP contains an oxidizing agent.
  • a polishing liquid that does not contain an oxidizing agent for example, when an A6063 alloy, which is a kind of Al—Mg—Si alloy (6000 alloy), is polished, relatively large irregularities are generated. This unevenness is caused by the polishing rate of the portion (impurity precipitated phase) containing more elements such as Mg, Si, Fe, etc. on the alloy surface than the surrounding aluminum portion (solid solution phase). It is thought that it is caused by being slower than On the other hand, in the polishing liquid using an oxidizing agent, a polished surface with small irregularities is obtained, and the polishing rate of the alloy is improved. The reason for this is not clear, but it is thought that the oxidizing agent acts to the same extent on both the solid solution phase and the impurity precipitation phase on the alloy surface.
  • oxidizing agents include hydrogen peroxide, persulfates (eg, ammonium persulfate, sodium persulfate, potassium persulfate), nitric acid, periodate (eg, ammonium periodate, sodium periodate, potassium periodate) ), Hypochlorous acid, ozone water, etc., among which hydrogen peroxide is preferred.
  • persulfates eg, ammonium persulfate, sodium persulfate, potassium persulfate
  • nitric acid eg, ammonium periodate, sodium periodate, potassium periodate
  • Periodate eg, ammonium periodate, sodium periodate, potassium periodate
  • Hypochlorous acid ozone water, etc.
  • the content of the oxidizing agent is effective in eliminating unevenness on the surface of the aluminum-based material (for example, aluminum alloy), and the polishing rate is lowered due to insufficient oxidation of the aluminum-based material (for example, aluminum alloy). From the viewpoint of preventing this, it is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and still more preferably 0.05% by mass or more, based on the total mass of the polishing slurry for CMP.
  • the content of the oxidizing agent is preferably 0.10% by mass or more, more preferably 0.20% by mass or more, and 0.30% by mass based on the total mass of the polishing slurry for CMP from the viewpoint of further improving the polishing rate. The above is more preferable.
  • the content of the oxidizing agent is preferably 50% by mass or less, more preferably 30% by mass or less, still more preferably 10% by mass or less, and further preferably 5% by mass or less, from the viewpoint of preventing the surface to be polished from being rough or causing scratches. Is particularly preferable, and 3% by mass or less is very preferable.
  • the CMP polishing liquid according to this embodiment includes a liquid medium for dispersing abrasive grains.
  • a liquid medium for dispersing abrasive grains.
  • the liquid medium is not particularly limited as long as it can disperse the abrasive grains.
  • the liquid medium preferably contains water as a main component.
  • deionized water, ion exchange water, ultrapure water, or the like is preferable.
  • the organic solvent that can be used as the liquid medium is not particularly limited, but a solvent that can be arbitrarily mixed with water is preferable.
  • organic solvents include acetic acid, glycols, glycol monoethers, glycol diethers, alcohols, carbonates, lactones, ethers, ketones, phenol, dimethylformamide, n-methylpyrrolidone, acetic acid Examples include ethyl, ethyl lactate, and sulfolane.
  • a liquid medium may be used individually by 1 type, and 2 or more types may be mixed and used for it.
  • the polishing slurry for CMP according to this embodiment has a pH of 11.5 or less.
  • the pH is defined as the pH at a liquid temperature of 25 ° C.
  • the pH is preferably 11.0 or less, more preferably 10.5 or less, and even more preferably 10.3 or less, from the viewpoint of easily suppressing an increase in surface roughness.
  • the pH of the polishing slurry for CMP according to this embodiment is preferably 7.0 or more, more preferably 7.5 or more, still more preferably 8.0 or more, from the viewpoint of easily improving the polishing rate of the aluminum-based material. .5 or more is particularly preferable, and 9.0 or more is extremely preferable.
  • the pH of the polishing slurry for CMP can be adjusted by acid components such as sulfuric acid, hydrochloric acid, and phosphoric acid; alkaline components such as ammonia, sodium hydroxide, potassium hydroxide, TMAH (tetramethylammonium hydroxide), and imidazole.
  • acid components such as sulfuric acid, hydrochloric acid, and phosphoric acid
  • alkaline components such as ammonia, sodium hydroxide, potassium hydroxide, TMAH (tetramethylammonium hydroxide), and imidazole.
  • a buffer solution may be added to the CMP polishing solution. Examples of such a buffer include an acetate buffer and a phthalate buffer.
  • the pH of the polishing slurry for CMP can be measured with a pH meter (for example, model number: PHL-40, manufactured by Electrochemical Instrument Co., Ltd.).
  • a pH meter for example, model number: PHL-40, manufactured by Electrochemical Instrument Co., Ltd.
  • standard buffer solution phthalate pH buffer solution pH: 4.01 (25 ° C), neutral phosphate pH buffer solution pH: 6.86 (25 ° C), borate pH buffer solution After calibrating three points using the solution pH: 9.18 (25 ° C.), the value after the electrode has been put into the CMP polishing solution and stabilized for 2 minutes or more can be adopted.
  • the CMP polishing liquid according to this embodiment can contain a surfactant or the like.
  • the CMP polishing liquid according to the present embodiment can be stored as a storage liquid used by being diluted with a liquid medium such as water at the time of use from the viewpoint of suppressing costs related to storage, transportation, storage and the like.
  • the storage liquid according to the present embodiment is a storage liquid for obtaining a CMP polishing liquid, and the CMP polishing liquid is obtained by diluting with a liquid medium (for example, diluting twice or more on a mass basis).
  • a CMP polishing liquid may be prepared by diluting a storage liquid with a liquid medium immediately before polishing.
  • a storage liquid and a liquid medium may be supplied on a platen (polishing surface plate) to prepare a CMP polishing liquid on the platen. Moreover, you may add these at the time of use, without mix
  • the lower limit of the dilution ratio (mass basis) of the stock solution is preferably 2 times or more and more preferably 3 times or more from the viewpoint that the higher the magnification is, the higher the effect of suppressing costs related to storage, transportation, storage and the like.
  • an upper limit of a dilution rate 10 times or less are preferable, 7 times or less are more preferable, and 5 times or less are still more preferable.
  • the upper limit of the dilution ratio is such that the content of components (chemical components such as acids and oxidizing agents, abrasive grains, etc.) contained in the stock solution is prevented from becoming too high, There is a tendency to maintain stability.
  • the dilution rate is d times, the content of the components contained in the storage liquid is d times the content of the components contained in the CMP polishing liquid.
  • the polishing slurry for CMP according to this embodiment is suitable for CMP of a substrate containing at least an aluminum-based material.
  • aluminum materials pure aluminum (1000 series); Al—Cu (2000 series), Al—Mn (3000 series), Al—Si (4000 series), Al—Mg (5000 series), Al—Mg—Si (6000 series), Al-Zn-Mg (7000 series) and other aluminum alloys.
  • Pure aluminum refers to aluminum to which a different element is not intentionally added.
  • the names of these aluminum-based materials conform to Japanese Industrial Standards (JIS) or international aluminum alloy names.
  • the CMP polishing liquid according to the present embodiment is suitable for polishing an aluminum alloy having a harder portion than pure aluminum.
  • aluminum alloys having parts harder than pure aluminum include Al—Cu (2000 series), Al—Mn (3000 series), Al—Si (4000 series), Al—Mg (5000 series), Al— Mg-Si (6000 series), Al-Zn-Mg (7000 series) and the like can be mentioned.
  • Al—Mg—Si (A6063 series) or Al—Mg (A5052) is preferable from the viewpoint of easily utilizing the characteristics of the polishing slurry for CMP according to the present embodiment.
  • the substrate containing an aluminum-based material is not particularly limited, but may be a substrate such as a semiconductor substrate, a part such as an aircraft part or an automobile part, a vehicle such as a railway vehicle, a case of an electronic device (such as a portable electronic device). Can be mentioned.
  • the surface of the substrate containing the aluminum-based material (for example, an aluminum alloy) can be polished sufficiently smoothly.
  • the CMP polishing liquid according to this embodiment is particularly suitable for polishing a substrate (for example, a casing) that requires a beautiful appearance.
  • a substrate having a surface roughness (Ra) before polishing of 5.0 nm or more and a surface roughness (Ra) after polishing of 4.0 nm or less are used. It may be used for polishing.
  • the surface roughness (Ra) of the substrate is preferably less than 20.0 nm, more preferably less than 15.0 nm, and even more preferably less than 10.0 nm before polishing from the viewpoint of easily obtaining a smooth surface.
  • the surface roughness (Ra) of the substrate is preferably 5.0 nm or more, more preferably 6.0 nm or more, and even more preferably 7.0 nm or more before polishing.
  • the polishing method according to the present embodiment may include a polishing step of polishing a substrate containing an aluminum-based material using a CMP polishing liquid, and dilute the storage liquid with a liquid medium (for example, twice on a mass basis).
  • a polishing step for polishing a substrate containing an aluminum-based material using a polishing slurry for CMP obtained by diluting as described above may be provided.
  • the surface roughness (Ra) before polishing of the substrate is, for example, 5.0 nm or more
  • the surface roughness (Ra) after polishing of the substrate is, for example, 4.0 nm or less. That is, in the polishing step, for example, a substrate having a surface roughness (Ra) of 5.0 nm or more is polished by using a CMP polishing liquid to obtain a substrate having a surface roughness (Ra) of 4.0 nm or less. It may be a step of obtaining.
  • the surface roughness (Ra) of the substrate is preferably less than 20.0 nm, more preferably less than 15.0 nm, and even more preferably less than 10.0 nm before polishing from the viewpoint of easily obtaining a smooth surface.
  • the surface roughness (Ra) of the substrate is preferably 5.0 nm or more, more preferably 6.0 nm or more, and even more preferably 7.0 nm or more before polishing.
  • a known polishing apparatus can be widely used.
  • a polishing apparatus a general polishing apparatus having a holder for holding a substrate and a platen on which a polishing pad (polishing cloth) is attached can be mentioned.
  • a motor or the like for changing the rotation speed of the platen may be attached to the platen.
  • polishing pad A general nonwoven fabric, a polyurethane foam, a porous fluororesin, etc. are mentioned. It is preferable that a groove is formed on the surface of these polishing pads so that the polishing liquid for CMP is accumulated.
  • the polishing conditions for the substrate are not limited, but from the viewpoint of easily preventing the substrate from popping out, the platen rotation speed is preferably 200 min ⁇ 1 or less.
  • the polishing load is preferably 34.5 kPa (5 psi) or less from the viewpoint of easily suppressing the occurrence of scratches on the substrate surface after polishing.
  • a CMP polishing liquid is supplied between the substrate and the polishing pad by a pump or the like in a state where the substrate including the aluminum-based material is pressed against the polishing pad attached to the platen. Then, the base and the platen are moved relative to each other. By these operations, chemical mechanical polishing can be performed on the substrate surface.
  • the method for supplying the CMP polishing liquid to the polishing apparatus is not particularly limited as long as the CMP polishing liquid can be continuously supplied to the polishing pad during polishing.
  • the supply amount of the polishing liquid for CMP is not limited, but it is preferable that the surface of the polishing pad is always covered with the polishing liquid for CMP. Polishing may be performed while supplying a storage liquid and a liquid medium such as water between the substrate and the polishing pad, and diluting the storage liquid on the platen (for example, diluting it twice or more on a mass basis).
  • the substrate after polishing is preferably washed with water, ethanol, isopropyl alcohol, or the like, and then dried after removing droplets (for example, water droplets) adhering to the substrate with a spin dryer or the like.
  • the pH was measured using a model number: PHL-40, manufactured by Electrochemical Instrument Co., Ltd.
  • an appropriate amount of liquid containing abrasive grains to be measured was measured in a container.
  • the chip obtained by cutting the wafer with pattern wiring into 2 cm square was immersed in the liquid in the container for about 30 seconds.
  • the chip was transferred to a container containing deionized water, rinsed for about 30 seconds, and the chip was blown with nitrogen. Thereafter, the chip was placed on a sample stage for scanning electron microscope observation, and particles were observed at an appropriate magnification (for example, 200,000 times) with an acceleration voltage of 10 kV, and a projected image was taken.
  • Arbitrary 80 particles were selected from the obtained projection image.
  • the rectangle (circumscribed rectangle) 2 circumscribing the measurement particle 1 is guided so that the length DL of the major axis of the rectangle 2 becomes the longest.
  • the biaxial average particle diameter ( ⁇ (DL ⁇ DS)) was calculated for each particle on the basis of the length DL of the major axis of the rectangle 2 and the length DS of the minor axis orthogonal to the major axis. This operation was performed on arbitrary 80 particles, and the obtained values were averaged to obtain a primary particle size.
  • the area S and the perimeter L of the particle in the projection image were obtained.
  • the ratio of the peripheral length L ′ to the peripheral length L (L '/ L) was calculated. This operation was performed on arbitrary 80 particles, and the obtained values were averaged to obtain the circularity.
  • the ratio of the length DS of the short diameter to the length DL of the long diameter was obtained for any 80 particles, and the values were averaged to obtain the sphericity.
  • the area S and the perimeter L of the particles in the projected image were measured using image analysis software (ImageJ, manufactured by National Institutes of Health).
  • Table 1 shows the measurement results of primary particle size, circularity and sphericity.
  • Example 1 Effect of circularity of colloidal silica> (Example 1) After adding colloidal silica A to deionized water, 30 mass% hydrogen peroxide water was added to prepare a stock solution 1 corresponding to the polishing slurry 1 for CMP of Example 1. In the process of preparing the stock solution 1, the content of colloidal silica A is 30% by mass based on the total mass of the stock solution 1, and the content of hydrogen peroxide is 0 based on the total mass of the stock solution 1. Colloidal silica A and hydrogen peroxide solution were added to prepare storage solution 1 so as to be .60% by mass (2.00% by mass in terms of 30% by mass hydrogen peroxide solution).
  • Polishing liquid 1 was prepared by diluting the storage liquid 1 with water twice (mixing the storage liquid with deionized water having the same mass as the storage liquid). That is, in the polishing liquid 1, the content of colloidal silica A is 15% by mass based on the total mass of the polishing liquid 1, and the hydrogen peroxide content is 0.30% by mass based on the total mass of the polishing liquid 1. Met.
  • the pH of the polishing liquid 1 was adjusted to 10.0 with potassium hydroxide.
  • Example 2 In Example 2, an experiment was performed in the same manner as in Example 1 except that colloidal silica B was added as abrasive grains, and a stock solution 2 and a polishing solution 2 were produced. The pH of the polishing liquid 2 was adjusted to 10.0 with potassium hydroxide.
  • Example 3 In Example 3, an experiment was performed in the same manner as in Example 1 except that equal amounts of colloidal silica A and colloidal silica G were added as abrasive grains. That is, after adding colloidal silica A and colloidal silica G to deionized water, 30 mass% hydrogen peroxide water was added to prepare a stock solution 3 corresponding to the polishing slurry 3 for CMP. In the process of preparing the stock solution 3, the content of colloidal silica A is 15% by mass based on the total mass of the stock solution 3, and the content of colloidal silica G is 15 based on the total mass of the stock solution 3.
  • Comparative Example 1 In Comparative Example 1, an experiment was performed in the same manner as in Example 1 except that colloidal silica C was added as abrasive grains, and a storage liquid 1X and a polishing liquid 1X were produced. The pH of the polishing liquid 1X was adjusted to 10.0 with potassium hydroxide.
  • Comparative Example 2 In Comparative Example 2, an experiment was performed in the same manner as in Example 1 except that colloidal silica D was added as abrasive grains, and a stock solution 2X and a polishing solution 2X were produced. The pH of the polishing liquid 2X was adjusted to 10.0 with potassium hydroxide.
  • Comparative Example 3 In Comparative Example 3, an experiment was performed in the same manner as in Example 1 except that colloidal silica E was added as abrasive grains, and a stock solution 3X and a polishing solution 3X were produced. The pH of the polishing liquid 3X was adjusted to 10.0 with potassium hydroxide.
  • Comparative Example 4 In Comparative Example 4, an experiment was performed in the same manner as in Example 1 except that colloidal silica F was added as abrasive grains, and a storage liquid 4X and a polishing liquid 4X were produced. The pH of the polishing liquid 4X was adjusted to 10.0 with potassium hydroxide.
  • Comparative Example 5 In Comparative Example 5, an experiment was performed in the same manner as in Example 1 except that colloidal silica G was added as abrasive grains, and a stock solution 5X and a polishing solution 5X were produced. The pH of the polishing liquid 5X was adjusted to 10.0 with potassium hydroxide.
  • Comparative Example 6 In Comparative Example 6, an experiment was performed in the same manner as in Example 1 except that colloidal silica H was added as abrasive grains, and a storage liquid 6X and a polishing liquid 6X were produced. The pH of the polishing liquid 6X was adjusted to 10.0 with potassium hydroxide.
  • polishing liquids 1 to 3 and polishing liquids 1X to 6X containing 15% by mass of abrasive grains and 0.30% by mass of an oxidizing agent were prepared based on the total mass of the polishing liquid.
  • polishing characteristic evaluation method The substrate was subjected to chemical mechanical polishing with a polishing liquid for CMP using the polishing apparatus in the following procedure.
  • the platen was rotated while supplying the CMP polishing liquid between the substrate and the polishing pad with a pump while pressing the following substrate on the polishing pad attached to the platen. By these operations, chemical mechanical polishing of the substrate surface was performed.
  • A6063 which is an Al—Mg—Si alloy plate, was used as the substrate to be polished.
  • the size of the substrate was 30 mm wide ⁇ 30 mm long ⁇ 5 mm thick.
  • polishing apparatus As a polishing apparatus, model FACT-200 manufactured by Nano Factor Co., Ltd. was used. A foamed polyurethane resin having closed cells was used as a polishing pad.
  • the polishing conditions were as follows.
  • Polishing load 9.0 kPa (1.3 psi) Platen rotation speed: 150 min -1 (rpm) Flow rate (supply amount) of polishing liquid for CMP: 3 mL / min Polishing time: 10 min
  • the polished mass was determined by measuring the mass of the substrate before and after CMP using each polishing liquid. Using the surface area and density values of the substrate to be polished (assuming the substrate is pure aluminum and using a density of 2.70 g / cm 3 ), the polished mass is converted into a film thickness and the polishing rate is calculated. did.
  • the evaluation results for Examples 1 to 3 and Comparative Examples 1 to 6 are shown in Table 2.
  • Example 4 Effect of pH> Example 4
  • the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 7.0 with sulfuric acid to prepare the polishing solution 4.
  • Example 5 In Example 5, the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 8.0 with sulfuric acid to prepare the polishing solution 5.
  • Example 6 In Example 6, the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 9.0 with sulfuric acid to prepare the polishing solution 6.
  • Example 7 the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 11.0 with potassium hydroxide to prepare the polishing solution 7.
  • Comparative Example 7 (Comparative Example 7)
  • the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 12.0 with potassium hydroxide to prepare a polishing solution 7X.
  • Example 8 Effect of oxidizing agent>
  • the content of hydrogen peroxide contained in the stock solution was adjusted to 0.10% by mass (0.33% by mass in terms of 30% by mass hydrogen peroxide solution), and the stock solution was doubled with water.
  • a storage solution 8 and a polishing solution 8 were prepared by the same procedure as in Example 1 except that the content of hydrogen peroxide in the polishing solution obtained by dilution was adjusted to 0.05 mass%.
  • the resulting polishing liquid 8 had a pH of 10.0.
  • Example 9 In Example 9, the content of hydrogen peroxide contained in the stock solution is adjusted to 1.50% by mass (5.00% by mass in terms of 30% by mass hydrogen peroxide solution), and the stock solution is doubled with water.
  • a storage solution 9 and a polishing solution 9 were prepared in the same manner as in Example 1 except that the content of hydrogen peroxide in the polishing solution obtained by dilution was adjusted to 0.75% by mass.
  • the resulting polishing liquid 9 had a pH of 10.0.
  • Comparative Example 8 In Comparative Example 8, a storage solution 8X and a polishing solution 8X were prepared by the same procedure as in Example 1 except that no hydrogen peroxide solution was added. The resulting polishing liquid 8X had a pH of 10.0.
  • a polishing liquid for CMP, a storage liquid and a polishing method using these according to the present invention include a substrate such as a semiconductor substrate, an aircraft part, a part such as an automobile part, a vehicle such as a railway vehicle, an electronic device (portable electronic device, etc.) It is suitable for CMP of the housing of the above.
  • Measurement particle 1 ... Measurement particle, 1a ... A perfect circle of the same area as the measurement particle, 2 ... A circumscribed rectangle.

Abstract

This CMP polishing solution for polishing a substrate including an aluminium-based material includes abrasive grains, an oxidant, and a liquid medium. The circularity of the abrasive grains is not more than 0.90. The pH of the CMP polishing solution is not more than 11.5.

Description

ＣＭＰ用研磨液、貯蔵液及び研磨方法Polishing liquid for CMP, storage liquid and polishing method
　本発明は、化学機械研磨（ＣＭＰ：Ｃｈｅｍｉｃａｌ　Ｍｅｃｈａｎｉｃａｌ　Ｐｏｌｉｓｈｉｎｇ）に使用するためのＣＭＰ用研磨液、当該研磨液を得るための貯蔵液、及び、これらを使用した研磨方法に関する。 The present invention relates to a CMP polishing liquid for use in chemical mechanical polishing (CMP), a storage liquid for obtaining the polishing liquid, and a polishing method using these.
　鉄道車両、航空機部品、自動車部品、電子機器の筐体等の材質としては、耐食性又は強度等に優れるという理由から、鉄と他の金属（クロム、ニッケル等）との合金であるステンレス鋼が用いられることが多い。しかしながら、ステンレス鋼の密度は７．６４～８．０６ｇ／ｃｍ３程度であり、ステンレス鋼では、近年の材料の軽量化への要求に対応するには限界がある。 Stainless steel, which is an alloy of iron and other metals (chromium, nickel, etc.), is used as the material for the chassis of railway vehicles, aircraft parts, automobile parts, electronic equipment, etc., because of its excellent corrosion resistance or strength. It is often done. However, the density of stainless steel is about 7.64 to 8.06 g / cm 3 , and stainless steel has a limit to meet the recent demand for weight reduction of materials.
　そのため、密度が２．６４～２．８２ｇ／ｃｍ３程度（ステンレス鋼の約１／３）であるアルミニウム系材料が注目されている。アルミニウム系材料としては、純アルミニウム（１０００系）、Ａｌ－Ｃｕ（２０００系）、Ａｌ－Ｍｎ（３０００系）、Ａｌ－Ｓｉ（４０００系）、Ａｌ－Ｍｇ（５０００系）、Ａｌ－Ｍｇ－Ｓｉ（６０００系）、Ａｌ－Ｚｎ－Ｍｇ（７０００系）等が知られている。 Therefore, aluminum-based materials having a density of about 2.64 to 2.82 g / cm 3 (about 1/3 of stainless steel) are attracting attention. Aluminum materials include pure aluminum (1000 series), Al—Cu (2000 series), Al—Mn (3000 series), Al—Si (4000 series), Al—Mg (5000 series), Al—Mg—Si. (6000 series), Al—Zn—Mg (7000 series) and the like are known.
　前記アルミニウム系材料のうち、純アルミニウム（１０００系）の強度はやや低めであるが、アルミニウム合金は、ステンレス鋼と同様に耐食性、強度に優れることに加え、加工性等にも優れる。また、ステンレス鋼を用いた材料のほとんどが、クロムに由来するやや黒味がかった銀色を呈しているのに対し、アルミニウム合金を用いた材料は、白銀色とすることが可能であり、見た目にも明るく美しくできる。 Among the aluminum-based materials, the strength of pure aluminum (1000-based) is slightly low, but the aluminum alloy is excellent in workability and the like in addition to being excellent in corrosion resistance and strength like stainless steel. In addition, most materials using stainless steel have a slightly blackish silver color derived from chrome, whereas materials using aluminum alloys can be white silvery in appearance. Can be bright and beautiful.
　美しい白銀色を得るために、アルミニウム系材料の表面を充分に平滑化することが求められる場合がある。アルミニウム系材料の研磨方法としては、機械的研磨と化学的研磨が挙げられる。 In order to obtain a beautiful white silver color, it may be required to sufficiently smooth the surface of the aluminum-based material. Examples of the method for polishing an aluminum-based material include mechanical polishing and chemical polishing.
　機械的研磨によって仕上げたアルミニウム系材料の表面は、金属光沢が消失しているもの（例えば、方向性のない模様があるもの、方向性のある筋模様があるもの）が多い。また、比較的平滑化が可能なバフ研磨を用いた場合であっても、充分に平滑な表面が得られるとはいえない。機械的研磨の中には、ある程度の金属光沢が得られる方法があるが、機械的研磨で得られる光沢には限界がある。このように、アルミニウム系材料の研磨において充分に平滑な表面が求められる場合、従来の機械的研磨ではその要求を満たすことが難しい。 The surface of aluminum-based materials finished by mechanical polishing often has a metallic luster that has disappeared (for example, a pattern with no directionality or a pattern with directionality). Further, even when buffing that can be relatively smoothed is used, it cannot be said that a sufficiently smooth surface is obtained. There is a method for obtaining a certain level of metallic luster in mechanical polishing, but there is a limit to the gloss that can be obtained by mechanical polishing. As described above, when a sufficiently smooth surface is required in the polishing of an aluminum-based material, it is difficult to satisfy the requirement by the conventional mechanical polishing.
　一方、平滑なアルミニウム系材料の表面を得る場合には、化学的研磨が用いられることがある。化学的研磨のみによる平滑化処理は工程に時間がかかるため、前記機械的研磨による処理を施した表面に、化学的研磨による処理を施すことがある。 On the other hand, chemical polishing may be used to obtain a smooth aluminum-based material surface. Since the smoothing process using only chemical polishing takes time, the surface subjected to the mechanical polishing process may be subjected to a chemical polishing process.
　化学的研磨方法としては、リン酸と硝酸を主成分とした研磨液又は溶剤を１１０℃以下に加熱し、そこへアルミニウムを浸漬する方法が知られている（例えば、下記特許文献１参照）。また、高価なリン酸を節約するため、リン酸の一部の代替として硫酸を用いることが知られている（例えば、下記特許文献２参照）。これらの研磨は、単に、アルミニウム系材料の表面を溶解させ、化学的な作用のみで表面の凸部を除去して平滑化するものであり、ＣＭＰとは異なる。 As a chemical polishing method, there is known a method in which a polishing liquid or a solvent mainly composed of phosphoric acid and nitric acid is heated to 110 ° C. or lower and aluminum is immersed therein (for example, see Patent Document 1 below). In order to save expensive phosphoric acid, it is known to use sulfuric acid as a substitute for a part of phosphoric acid (see, for example, Patent Document 2 below). These polishings are different from CMP in that the surface of the aluminum-based material is simply dissolved and the convex portions on the surface are removed and smoothed only by chemical action.
　ここで、ＣＭＰとは、機械的な作用と化学的な作用の両方を利用した研磨のことである。具体的には、化学的な作用でアルミニウム系材料を軟化又は溶解させながら、同時に、アルミニウム系材料と砥粒との摩擦による機械的な作用でアルミニウム系材料の表面の凸部を除去して平滑化する場合がある。 Here, CMP is polishing using both mechanical action and chemical action. Specifically, while softening or dissolving the aluminum-based material by a chemical action, at the same time, the surface of the aluminum-based material is removed by a mechanical action due to friction between the aluminum-based material and abrasive grains to smooth the surface. There is a case.
　被研磨面の光沢を向上させるために酢酸を添加する方法も知られており、例えばリン酸５０～８０質量％、硝酸５～２０質量％、酢酸３～２０質量％を含有する液体を用いる手法が知られている（例えば、下記特許文献１参照）。被研磨面の光沢を向上させるために添加する物質としては、酢酸の他に、シュウ酸、クエン酸等の有機物質も知られている（例えば、下記非特許文献１参照）。 A method of adding acetic acid to improve the gloss of the surface to be polished is also known. For example, a method using a liquid containing 50 to 80% by mass of phosphoric acid, 5 to 20% by mass of nitric acid, and 3 to 20% by mass of acetic acid. Is known (see, for example, Patent Document 1 below). In addition to acetic acid, organic substances such as oxalic acid and citric acid are also known as substances added to improve the gloss of the surface to be polished (for example, see Non-Patent Document 1 below).
　このように、従来、充分に平滑なアルミニウム系材料の表面を得るためには、機械的研磨と化学的研磨の２ステップで研磨することが必要とされることからコストの増大が避けられず、また、高濃度の酸を高温で用いることが必要であるためプロセス管理が難しいという問題がある。 Thus, conventionally, in order to obtain a sufficiently smooth surface of an aluminum-based material, since it is necessary to polish in two steps of mechanical polishing and chemical polishing, an increase in cost is inevitable, Moreover, since it is necessary to use a high concentration acid at high temperature, there is a problem that process management is difficult.
　一方、アルミニウム系材料をＣＭＰにより研磨することも検討されている。アルミニウム系材料を研磨するためのＣＭＰ用研磨液はいくつか知られているが（例えば、下記特許文献３参照）、その種類は豊富とはいえない。 On the other hand, polishing of an aluminum-based material by CMP has also been studied. Several polishing liquids for CMP for polishing aluminum-based materials are known (for example, see Patent Document 3 below), but the types are not abundant.
　特許文献３では、砥粒としてアルミナ粒子を含むＣＭＰ用研磨液が記載されている。しかしながら、アルミニウム系材料は軟質であるために、アルミナ粒子を含有するＣＭＰ用研磨液を用いてＣＭＰを行うと、表面粗さが増大しやすい。この表面粗さの増大は、歩留まりを著しく低下させる。これに対し、砥粒として、より軟質なコロイダルシリカは、表面粗さに有効であることが知られている（例えば、下記特許文献４、５参照）。 Patent Document 3 describes a CMP polishing liquid containing alumina particles as abrasive grains. However, since the aluminum-based material is soft, the surface roughness tends to increase when CMP is performed using a CMP polishing liquid containing alumina particles. This increase in surface roughness significantly reduces the yield. On the other hand, it is known that softer colloidal silica is effective for surface roughness as abrasive grains (see, for example, Patent Documents 4 and 5 below).
特開昭５９－１１３１９９号公報JP 59-113199 A 特開２００２－２８５３６０号公報JP 2002-285360 A 特表２０１１－５１７５０７号公報Special table 2011-517507 gazette 特開昭５２－８１６９２号公報JP 52-81692 A 特表２００８－５４４８６８公報Special table 2008-544868
　しかしながら、表面粗さの低減は、未だ充分であるとはいえない。 However, the reduction in surface roughness is still not sufficient.
　本発明は、前記問題点に鑑みなされたものであり、アルミニウム系材料を含む基体を平滑に研磨できるＣＭＰ用研磨液、当該研磨液を得るための貯蔵液、及び、これらを使用した研磨方法を提供することを目的とする。 The present invention has been made in view of the above problems, and provides a polishing liquid for CMP capable of smoothly polishing a substrate containing an aluminum-based material, a storage liquid for obtaining the polishing liquid, and a polishing method using these. The purpose is to provide.
　本発明者は、走査型電子顕微鏡（ＳＥＭ）観察により得られる砥粒の粒子形状を解析して求められる円形度の値が特定値以下の場合に、表面粗さが小さくなることを見いだした。 The present inventor has found that the surface roughness is reduced when the circularity value obtained by analyzing the particle shape of the abrasive grains obtained by observation with a scanning electron microscope (SEM) is below a specific value.
　すなわち、本発明に係るＣＭＰ用研磨液は、アルミニウム系材料を含む基体を研磨するためのＣＭＰ用研磨液であって、砥粒、酸化剤及び液状媒体を含み、砥粒の円形度が０．９０以下であり、ＣＭＰ用研磨液のｐＨが１１．５以下である。 That is, the CMP polishing liquid according to the present invention is a CMP polishing liquid for polishing a substrate containing an aluminum-based material, and contains abrasive grains, an oxidizing agent, and a liquid medium, and the circularity of the abrasive grains is 0. 90 or less, and the pH of the polishing slurry for CMP is 11.5 or less.
　本発明に係るＣＭＰ用研磨液によれば、アルミニウム系材料を含む基体を平滑に研磨できる。また、本発明に係るＣＭＰ用研磨液によれば、アルミニウム合金の表面のうち、アルミニウムからなる部分と、アルミニウムに加えて異種元素を含む部分とを同等に平坦に研磨できるため、アルミニウム合金を含む基体を平滑に研磨できる。 According to the polishing slurry for CMP according to the present invention, a substrate containing an aluminum-based material can be polished smoothly. Further, according to the polishing slurry for CMP according to the present invention, the aluminum alloy surface can be equally flatly polished on the aluminum alloy surface and the portion containing different elements in addition to aluminum. The substrate can be polished smoothly.
　また、本発明者らは、できるだけ短時間に表面粗さを低減するためには、研磨速度が高い方がよいことを見いだした。研磨速度が高いことにより、全体の作業時間が短くなる（スループットが向上する）という効果もある。しかしながら、本発明者らは、従来のどのような砥粒を用いたとしても、良好な表面粗さを有しながら研磨速度を高くすること、すなわち、表面粗さと研磨速度とを両立することが難しいというトレードオフの問題があることを見いだした。本発明者らは、例えば、表面粗さと研磨速度とを両立する観点から、研磨速度を大きくするために砥粒の粒径を大きくすると、表面粗さが悪化してしまう傾向があり、逆に、砥粒の粒径を小さくすると、表面粗さが向上するものの研磨速度が低下してしまう傾向があることを見いだした。 In addition, the present inventors have found that a higher polishing rate is better in order to reduce the surface roughness in the shortest possible time. The high polishing rate also has the effect of shortening the overall work time (improving throughput). However, the present inventors are able to increase the polishing rate while having a good surface roughness, that is, to achieve both the surface roughness and the polishing rate, regardless of the conventional abrasive grains. I found it difficult to trade off. For example, from the viewpoint of achieving both a surface roughness and a polishing rate, the inventors have a tendency that the surface roughness tends to deteriorate when the grain size of the abrasive grains is increased in order to increase the polishing rate. It has been found that when the grain size of the abrasive grains is reduced, the polishing rate tends to decrease although the surface roughness is improved.
　これに対し、本発明者らは、走査型電子顕微鏡（ＳＥＭ）観察により得られる砥粒の粒子形状を解析して求められる円形度の値が特定値以下（０．９０以下）の場合に、表面粗さが小さくなると共に、研磨速度が著しく大きくなることを見いだした。本発明に係るＣＭＰ用研磨液によれば、アルミニウム系材料を含む基体を高速且つ平滑に研磨できる。また、本発明に係るＣＭＰ用研磨液によれば、アルミニウム合金を含む基体を高速且つ平滑に研磨できる。さらに、本発明によれば、アルミニウム合金等のアルミニウム系材料を含む基体を高速に研磨でき、平滑な表面を有する基体を簡便且つ効率的に得ることができる。 On the other hand, when the value of the circularity obtained by analyzing the particle shape of the abrasive grains obtained by observation with a scanning electron microscope (SEM) is a specific value or less (0.90 or less), the present inventors It has been found that the polishing rate increases remarkably as the surface roughness decreases. With the polishing slurry for CMP according to the present invention, a substrate containing an aluminum-based material can be polished at high speed and smoothly. In addition, according to the polishing slurry for CMP according to the present invention, a substrate containing an aluminum alloy can be polished at high speed and smoothly. Furthermore, according to the present invention, a substrate containing an aluminum-based material such as an aluminum alloy can be polished at high speed, and a substrate having a smooth surface can be obtained simply and efficiently.
　砥粒の真球度は、０．３０以上０．８０以下が好ましい。これにより、アルミニウム系材料を含む基体を高速且つ平滑に研磨しやすくなる。 The sphericity of the abrasive grains is preferably 0.30 or more and 0.80 or less. Thereby, it becomes easy to polish the substrate containing the aluminum-based material at high speed and smoothly.
　ＣＭＰ用研磨液のｐＨは、７．０以上であることが好ましい。これにより、アルミニウム系材料を含む基体を高速且つ平滑に研磨しやすくなる。 The pH of the CMP polishing liquid is preferably 7.0 or more. Thereby, it becomes easy to polish the substrate containing the aluminum-based material at high speed and smoothly.
　本発明に係る貯蔵液は、前記ＣＭＰ用研磨液を得るための貯蔵液であって、液状媒体で希釈することにより前記ＣＭＰ用研磨液が得られる。このような貯蔵液によれば、ＣＭＰ用研磨液の貯蔵、運搬、保管等に係るコストを低減できる。 The storage liquid according to the present invention is a storage liquid for obtaining the CMP polishing liquid, and the CMP polishing liquid can be obtained by diluting with a liquid medium. According to such a storage liquid, the cost related to storage, transportation, storage, etc. of the polishing liquid for CMP can be reduced.
　本発明に係る研磨方法の一態様は、前記ＣＭＰ用研磨液を用いて、アルミニウム系材料を含む基体を研磨する工程を備える。このような研磨方法によれば、アルミニウム系材料を含む基体を高速且つ平滑に研磨できると共に、アルミニウム系材料を含む基体を簡便且つ効率的に研磨できる。 An embodiment of the polishing method according to the present invention includes a step of polishing a substrate containing an aluminum-based material using the CMP polishing liquid. According to such a polishing method, a substrate containing an aluminum-based material can be polished smoothly at high speed, and a substrate containing an aluminum-based material can be polished easily and efficiently.
　本発明に係る研磨方法の他の一態様は、前記貯蔵液を液状媒体で希釈することにより得られるＣＭＰ用研磨液を用いて、アルミニウム系材料を含む基体を研磨する工程を備える。このような研磨方法によれば、ＣＭＰ用研磨液の貯蔵、運搬、保管等に係るコストを抑制できるため総合的な製造コストを低減できると共に、アルミニウム系材料を含む基体を高速且つ平滑に研磨できる。 Another aspect of the polishing method according to the present invention includes a step of polishing a substrate containing an aluminum-based material using a CMP polishing liquid obtained by diluting the storage liquid with a liquid medium. According to such a polishing method, the cost for storing, transporting, storing, etc. of the polishing liquid for CMP can be suppressed, so that the overall manufacturing cost can be reduced and the substrate containing the aluminum-based material can be polished smoothly at high speed. .
　本発明によれば、アルミニウム系材料を含む基体を平滑に研磨できるＣＭＰ用研磨液、当該研磨液を得るための貯蔵液、及び、これらを使用した研磨方法を提供できる。また、本発明によれば、アルミニウム系材料を含む基体を平滑且つ高速に研磨できるＣＭＰ用研磨液、当該研磨液を得るための貯蔵液、及び、これらを使用した研磨方法を提供できる。さらに、本発明によれば、アルミニウム系材料を含む基体の研磨を平滑且つ効率的に行うことのできる砥粒の選定方法を提供することもできる。 According to the present invention, it is possible to provide a CMP polishing liquid capable of smoothly polishing a substrate containing an aluminum-based material, a storage liquid for obtaining the polishing liquid, and a polishing method using these. Further, according to the present invention, it is possible to provide a polishing liquid for CMP capable of polishing a substrate containing an aluminum-based material smoothly and at high speed, a storage liquid for obtaining the polishing liquid, and a polishing method using these. Furthermore, according to this invention, the selection method of the abrasive grain which can perform the grinding | polishing of the base | substrate containing an aluminum-type material smoothly and efficiently can also be provided.
　従来のアルミニウム用研磨液は、純アルミニウムのみを研磨対象としたものであり、アルミニウム合金を研磨するためのものではなく、アルミニウム合金の研磨に適したＣＭＰ用研磨液は知られていない。これに対し、本発明によれば、アルミニウム合金を含む基体を高速且つ平滑に研磨できる。また、本発明によれば、アルミニウム合金等のアルミニウム系材料を含む基体を高速に研磨でき、平滑な表面を有する基体を簡便且つ効率的に得ることができる。 Conventional aluminum polishing liquids are intended for polishing pure aluminum only, and are not intended for polishing aluminum alloys, and CMP polishing liquids suitable for polishing aluminum alloys are not known. On the other hand, according to the present invention, a substrate containing an aluminum alloy can be polished at high speed and smoothly. Further, according to the present invention, a substrate containing an aluminum-based material such as an aluminum alloy can be polished at high speed, and a substrate having a smooth surface can be obtained simply and efficiently.
　本発明によれば、アルミニウム系材料を含む基体の研磨へのＣＭＰ用研磨液及び貯蔵液の応用が提供される。本発明によれば、アルミニウム合金を含む基体の研磨へのＣＭＰ用研磨液及び貯蔵液の応用が提供される。本発明によれば、研磨前における表面粗さ（Ｒａ）が５．０ｎｍ以上である基体を、研磨後における表面粗さ（Ｒａ）が４．０ｎｍ以下となるように研磨する研磨工程へのＣＭＰ用研磨液及び貯蔵液の応用が提供される。 According to the present invention, application of a polishing liquid for CMP and a storage liquid to polishing a substrate containing an aluminum-based material is provided. According to the present invention, application of a polishing liquid for CMP and a storage liquid to polishing a substrate containing an aluminum alloy is provided. According to the present invention, CMP to a polishing step of polishing a substrate having a surface roughness (Ra) before polishing of 5.0 nm or more so that the surface roughness (Ra) after polishing becomes 4.0 nm or less. Applications for polishing liquids and storage liquids are provided.
円形度の測定方法を説明するための図面である。It is drawing for demonstrating the measuring method of circularity. 一次粒径及び真球度の測定方法を説明するための図面である。It is drawing for demonstrating the measuring method of a primary particle size and a sphericity.
　以下、本発明の実施形態について説明する。但し、本発明は下記実施形態に何ら限定されるものではない。 Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiment.
［ＣＭＰ用研磨液］
　本実施形態に係るＣＭＰ用研磨液（アルミニウム用研磨液）は、アルミニウム系材料を含む基体を研磨するための研磨液である。本実施形態に係るＣＭＰ用研磨液は、砥粒、酸化剤及び液状媒体（例えば水）を含み、前記砥粒の円形度が０．９０以下であり、ＣＭＰ用研磨液のｐＨが１１．５以下であることを特徴とする。 [CMP polishing liquid]
The CMP polishing liquid (aluminum polishing liquid) according to this embodiment is a polishing liquid for polishing a substrate containing an aluminum-based material. The CMP polishing liquid according to the present embodiment includes abrasive grains, an oxidizing agent, and a liquid medium (for example, water), the circularity of the abrasive grains is 0.90 or less, and the pH of the CMP polishing liquid is 11.5. It is characterized by the following.
（砥粒）
　本実施形態に係るＣＭＰ用研磨液は、砥粒を含む。砥粒としては、フュームドシリカ、コロイダルシリカ等のシリカ（酸化珪素）、フュームドアルミナ、コロイダルアルミナ等のアルミナ（酸化アルミニウム）、焼成セリア、コロイダルセリア等のセリア（酸化セリウム）、ジルコニア（酸化ジルコニウム）などが挙げられる。中でも、アルミニウム系材料に対する高い研磨速度と、表面の平滑化の両立を図りやすい観点から、シリカが好ましく、コロイダルシリカがより好ましい。また、ＣＭＰ用研磨液は、一種又は二種以上の砥粒を含むことができる。二種以上の砥粒を用いる場合は、シリカを必須成分とすることが好ましく、コロイダルシリカを必須成分とすることがより好ましい。 (Abrasive grains)
The CMP polishing liquid according to the present embodiment includes abrasive grains. As abrasive grains, silica (silicon oxide) such as fumed silica and colloidal silica, alumina (aluminum oxide) such as fumed alumina and colloidal alumina, ceria (cerium oxide) such as calcined ceria and colloidal ceria, zirconia (zirconium oxide) ) And the like. Among these, silica is preferable and colloidal silica is more preferable from the viewpoint of easily achieving both a high polishing rate for an aluminum-based material and smoothing of the surface. In addition, the CMP polishing liquid may contain one kind or two or more kinds of abrasive grains. When two or more kinds of abrasive grains are used, silica is preferably an essential component, and colloidal silica is more preferably an essential component.
｛円形度｝
　砥粒の円形度は、０．９０以下である。円形度が０．９０以下であることにより、アルミニウム系材料を含む基体を高速且つ平滑に研磨することが可能であり、充分に平滑な被研磨面を短時間で効率よく得ることができる。同様の観点で、前記円形度は０．９０未満が好ましく、０．８７以下がより好ましく、０．８５以下が更に好ましい。また、研磨速度に更に優れる観点から、前記円形度は、０．８３以下が好ましく、０．８０以下がより好ましい。 {Circularity}
The circularity of the abrasive grains is 0.90 or less. When the circularity is 0.90 or less, a substrate containing an aluminum-based material can be polished smoothly at high speed, and a sufficiently smooth polished surface can be efficiently obtained in a short time. From the same viewpoint, the circularity is preferably less than 0.90, more preferably 0.87 or less, and still more preferably 0.85 or less. Further, from the viewpoint of further improving the polishing rate, the circularity is preferably 0.83 or less, and more preferably 0.80 or less.
　本実施形態に係るＣＭＰ用研磨液では、少なくとも一種の砥粒の円形度が０．９０以下であればよい。本実施形態に係るＣＭＰ用研磨液では、円形度が０．９０以下である砥粒のみが用いられてもよく、円形度が０．９０以下である砥粒と、円形度が０．９０を超える砥粒とが併用されていてもよい。円形度が０．９０以下である砥粒の含有量は、砥粒の全質量を基準として、３０質量％以上が好ましく、５０質量％以上がより好ましく、７５質量％以上が更に好ましく、９０質量％以上が特に好ましく、９５質量％以上が極めて好ましく、９８質量％以上が非常に好ましい。 In the CMP polishing liquid according to the present embodiment, the circularity of at least one abrasive grain may be 0.90 or less. In the polishing slurry for CMP according to this embodiment, only abrasive grains having a circularity of 0.90 or less may be used, and abrasive grains having a circularity of 0.90 or less and a circularity of 0.90. More abrasive grains may be used in combination. The content of abrasive grains having a circularity of 0.90 or less is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and 90% by mass based on the total mass of the abrasive grains. % Or more is particularly preferable, 95% by mass or more is very preferable, and 98% by mass or more is very preferable.
　砥粒の円形度は、粒子形状（すなわち、粒子表面の凹凸状態）を反映する指標である。円形度が１．００に近いほど、粒子投影図が、凹凸のない真円に近いことを意味する。円形度が０．９０を超える場合は、砥粒が真球に近い状態を有している。 The circularity of the abrasive grains is an index reflecting the particle shape (that is, the uneven state of the particle surface). The closer the circularity is to 1.00, the closer the particle projection diagram is to a perfect circle without irregularities. When the circularity exceeds 0.90, the abrasive has a state close to a true sphere.
　砥粒の円形度は、例えば、下記の手順により求めることができる。
　・複数の粒子が含まれる写真投影図（粒子投影図）を走査型電子顕微鏡により写真撮影して得る。
　・写真投影図における任意の８０個の粒子を選択する。
　・写真投影図における粒子の周囲長Ｌに対する、写真投影図における粒子の面積に等しい面積を有する真円の周囲長（外周）Ｌ’の比（Ｌ’／Ｌ）を各粒子について求める（例えば、図１（ａ）に示す測定粒子１の周囲長Ｌに対する、測定粒子１の面積Ｓに等しい面積を有する真円１ａ（図１（ｂ））の周囲長Ｌ’の比（Ｌ’／Ｌ）を求める）。
　・８０個の粒子の比Ｌ’／Ｌの平均を「円形度」として算出する。 The circularity of the abrasive grains can be determined, for example, by the following procedure.
A photograph projection view (particle projection view) containing a plurality of particles is obtained by photographing with a scanning electron microscope.
Select any 80 particles in the photographic projection.
The ratio (L ′ / L) of the circumference (outer circumference) L ′ of a perfect circle having an area equal to the area of the particles in the photographic projection to the circumference L of the photographic projection is obtained for each particle (for example, Ratio (L '/ L) of the circumference L' of the perfect circle 1a (Fig. 1 (b)) having an area equal to the area S of the measurement particle 1 to the circumference L of the measurement particle 1 shown in Fig. 1 (a) Seeking).
Calculate the average of the ratio L ′ / L of 80 particles as “circularity”.
　砥粒の円形度が０．９０以下であることにより、アルミニウム系材料に対する研磨速度が著しく向上し且つ平滑な被研磨面が得られる理由は定かではないが、本発明者は以下のように考えている。すなわち、砥粒の円形度が０．９０以下であると、粒子表面に凹凸が存在するようになり、表面が滑らかな真球状の砥粒と比較して、表面積が大きくなって、砥粒とアルミニウム系材料との接触面積が大きくなると推察される。これにより、大きな摩擦が生じやすくなるため研磨速度が大きくなると推察される。一方で、アルミニウム系材料と砥粒との接触面積が大きくなると、真球状の砥粒と比較して、被研磨面の深さ方向ではなく、水平方向の研磨の進行が速くなると推察される。これにより、被研磨面の凹凸のうち、上部に位置する凸部の研磨速度が選択的に速くなるため、平滑性が向上すると推察される。 The reason why the circularity of the abrasive grains is 0.90 or less can significantly improve the polishing rate for an aluminum-based material and obtain a smooth polished surface, but the present inventor thinks as follows. ing. That is, when the circularity of the abrasive grains is 0.90 or less, irregularities are present on the surface of the grains, and the surface area is increased compared to the spherical grains having a smooth surface. It is assumed that the contact area with the aluminum-based material increases. As a result, large friction is likely to occur, and it is assumed that the polishing rate increases. On the other hand, when the contact area between the aluminum-based material and the abrasive grains is increased, it is presumed that the progress of polishing in the horizontal direction rather than in the depth direction of the surface to be polished is accelerated as compared to the spherical abrasive grains. Thereby, since the polishing speed of the convex part located in the upper part among the unevenness | corrugations of a to-be-polished surface selectively becomes high, it is guessed that smoothness improves.
｛真球度｝
　砥粒の真球度は、アルミニウム系材料に対する研磨速度を高め且つ平滑なアルミニウム系材料の表面を得ることが容易である観点から、０．３０以上が好ましく、０．３５以上がより好ましく、０．４０以上が更に好ましく、０．４５以上が特に好ましく、０．５０以上が極めて好ましい。砥粒の真球度は、アルミニウム系材料に対する研磨速度を高め且つ平滑なアルミニウム系材料の表面を得ることが容易である観点から、０．８０以下が好ましく、０．７７以下がより好ましい。前記真球度は、研磨速度に更に優れる観点から、０．７５以下が好ましく、０．７０以下がより好ましい。真球度が０．３０未満である場合は、砥粒が細長い形状を有している。真球度が０．８０を超える場合は、砥粒が真球に近い状態を有している。なお、本実施形態に係るＣＭＰ用研磨液では、円形度が０．９０以下である少なくとも一種の砥粒が、前記真球度を有することが好ましい。 {Sphericity}
The sphericity of the abrasive grains is preferably 0.30 or more, more preferably 0.35 or more, from the viewpoint of easily increasing the polishing rate for the aluminum-based material and easily obtaining a smooth aluminum-based material surface. .40 or more is more preferable, 0.45 or more is particularly preferable, and 0.50 or more is very preferable. The sphericity of the abrasive grains is preferably 0.80 or less, and more preferably 0.77 or less, from the viewpoint of increasing the polishing rate for the aluminum-based material and easily obtaining a smooth aluminum-based material surface. The sphericity is preferably 0.75 or less, and more preferably 0.70 or less, from the viewpoint of further improving the polishing rate. When the sphericity is less than 0.30, the abrasive grains have an elongated shape. When the sphericity exceeds 0.80, the abrasive has a state close to a sphere. In the CMP polishing liquid according to this embodiment, it is preferable that at least one type of abrasive grains having a circularity of 0.90 or less has the sphericity.
　砥粒の真球度は、走査型電子顕微鏡により写真撮影して得られる写真投影図における粒子について、粒子の最大径を有する長径の当該最大径に対する、当該長径に直交する短径の長さの比（短径の長さ／最大径）の平均値を意味する。砥粒の真球度は、例えば、下記の手順により求めることができる。
　・複数の粒子が含まれる写真投影図（粒子投影図）を走査型電子顕微鏡により写真撮影して得る。
　・写真投影図における任意の８０個の粒子を選択する。
　・選択した粒子が例えば図２に示すような形状であった場合、測定粒子１に外接する長方形（外接長方形）２を、当該長方形２の長径の長さＤＬが最も長くなるように導く。
　・長方形２の長径の長さＤＬ、及び、長径に直交する短径の長さＤＳに基づき、長さＤＬに対する長さＤＳの比（ＤＳ／ＤＬ）を各粒子について求める。
　・８０個の粒子の比ＤＳ／ＤＬの平均を「真球度」として算出する。 The sphericity of the abrasive grains is the length of the minor axis perpendicular to the major axis with respect to the maximum diameter of the major axis having the maximum diameter of the particles in the photographic projection drawing obtained by photographing with a scanning electron microscope. Mean ratio (length of minor axis / maximum diameter). The sphericity of the abrasive grains can be determined, for example, by the following procedure.
A photograph projection view (particle projection view) containing a plurality of particles is obtained by photographing with a scanning electron microscope.
Select any 80 particles in the photographic projection.
When the selected particle has a shape as shown in FIG. 2, for example, the rectangle (circumscribed rectangle) 2 circumscribing the measurement particle 1 is guided so that the length DL of the major axis of the rectangle 2 becomes the longest.
Based on the length DL of the major axis of the rectangle 2 and the length DS of the minor axis orthogonal to the major axis, the ratio of the length DS to the length DL (DS / DL) is determined for each particle.
Calculate the average of the ratio DS / DL of 80 particles as “sphericity”.
　砥粒の真球度が０．３０以上０．８０以下であることにより、アルミニウム系材料に対する研磨速度を高め且つ平滑なアルミニウム系材料の表面を得ることが容易である理由は定かではないが、本発明者は以下のように考えている。すなわち、砥粒の真球度が０．３０以上０．８０以下であると、被研磨面と砥粒との接触面積が大きくなり、摩擦が生じやすくなって研磨速度が向上すると考えられる。一方、真球度が０．８０を超えると、被研磨面と砥粒との接触面積が低下するため、研磨速度が低くなると推察される。また、真球度が０．３０未満であると、粒子形状が棒状に近くなり、真球度が０．３０以上である場合と比較して、砥粒の運動方向が大きく制限されるため研磨速度が低下すると推察される。 Although the sphericity of the abrasive grains is 0.30 or more and 0.80 or less, the reason why it is easy to increase the polishing rate for the aluminum-based material and to obtain a smooth surface of the aluminum-based material is not clear, The present inventor considers as follows. That is, when the sphericity of the abrasive grains is 0.30 or more and 0.80 or less, it is considered that the contact area between the surface to be polished and the abrasive grains is increased, friction is easily generated, and the polishing rate is improved. On the other hand, when the sphericity exceeds 0.80, the contact area between the surface to be polished and the abrasive grains decreases, and it is assumed that the polishing rate decreases. Further, when the sphericity is less than 0.30, the particle shape is close to a rod shape, and the direction of movement of the abrasive grains is greatly limited as compared with the case where the sphericity is 0.30 or more. It is assumed that the speed will decrease.
｛一次粒径｝
　砥粒の一次粒径は、アルミニウム系材料に対する研磨速度を高め且つ平滑なアルミニウム系材料の表面を得ることが容易である観点から、５．０ｎｍ以上が好ましく、１０．０ｎｍ以上がより好ましく、１５．０ｎｍ以上が更に好ましい。砥粒の一次粒径は、表面平滑性が更に効率よく向上する観点から、１５０．０ｎｍ以下が好ましく、１２０．０ｎｍ以下がより好ましく、１００．０ｎｍ以下が更に好ましく、７０．０ｎｍ以下が特に好ましく、５０．０ｎｍ以下が極めて好ましい。 {Primary particle size}
The primary particle size of the abrasive grains is preferably 5.0 nm or more, more preferably 10.0 nm or more, from the viewpoint of easily increasing the polishing rate for the aluminum material and obtaining a smooth surface of the aluminum material. More preferably, it is 0.0 nm or more. The primary particle size of the abrasive grains is preferably 150.0 nm or less, more preferably 120.0 nm or less, still more preferably 100.0 nm or less, and particularly preferably 70.0 nm or less, from the viewpoint of improving the surface smoothness more efficiently. 50.0 nm or less is very preferable.
　砥粒の一次粒径は、走査型電子顕微鏡により写真撮影して得られる写真投影図における粒子について、粒子の最大径を有する長径の当該最大径と、当該長径に直交する短径の長さとの積の平方根（二軸平均粒径）の平均値を意味する。砥粒の一次粒径は、例えば、下記の手順により求めることができる。
　・複数の粒子が含まれる写真投影図（粒子投影図）を走査型電子顕微鏡により写真撮影して得る。
　・写真投影図における任意の８０個の粒子を選択する。
　・選択した粒子が例えば図２に示すような形状であった場合、測定粒子１に外接する長方形（外接長方形）２を、当該長方形２の長径の長さＤＬが最も長くなるように導く。
　・長方形２の長径の長さＤＬ、及び、長径に直交する短径の長さＤＳに基づき、二軸平均粒径（√（ＤＬ×ＤＳ））を各粒子について求める。
　・８０個の粒子の二軸平均粒径の平均を「一次粒径」として算出する。 The primary particle size of the abrasive grains is the maximum diameter of the major axis having the maximum diameter of the particle and the length of the minor axis perpendicular to the major axis of the particle in the photographic projection obtained by photographing with a scanning electron microscope. It means the average value of the square root of the product (biaxial average particle diameter). The primary particle size of the abrasive grains can be determined, for example, by the following procedure.
A photograph projection view (particle projection view) containing a plurality of particles is obtained by photographing with a scanning electron microscope.
Select any 80 particles in the photographic projection.
When the selected particle has a shape as shown in FIG. 2, for example, the rectangle (circumscribed rectangle) 2 circumscribing the measurement particle 1 is guided so that the length DL of the major axis of the rectangle 2 becomes the longest.
The biaxial average particle diameter (√ (DL × DS)) is determined for each particle based on the length DL of the major axis of the rectangle 2 and the length DS of the minor axis orthogonal to the major axis.
The average of the biaxial average particle diameters of 80 particles is calculated as “primary particle diameter”.
　ＣＭＰ用研磨液における砥粒の含有量は、研磨液が砥粒を含まない場合の研磨速度に対して充分に有意差がある研磨速度を達成しやすい観点から、ＣＭＰ用研磨液の全質量を基準として、１質量％以上が好ましく、２質量％以上がより好ましく、３質量％以上が更に好ましく、４質量％以上が特に好ましく、５質量％以上が極めて好ましい。ＣＭＰ用研磨液における砥粒の含有量は、含有量に応じた研磨速度の向上効果が得られやすい観点から、ＣＭＰ用研磨液の全質量を基準として、３０質量％以下が好ましく、２５質量％以下がより好ましく、２０質量％以下が更に好ましく、１７．５質量％以下が特に好ましく、１５質量％以下が極めて好ましい。前記の観点から、砥粒の含有量は、１～３０質量％が好ましい。 The content of abrasive grains in the polishing liquid for CMP is the total mass of the polishing liquid for CMP from the viewpoint of easily achieving a polishing speed that is sufficiently different from the polishing speed when the polishing liquid does not contain abrasive grains. As a reference, it is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 3% by mass or more, particularly preferably 4% by mass or more, and extremely preferably 5% by mass or more. The content of the abrasive grains in the CMP polishing liquid is preferably 30% by mass or less, preferably 25% by mass, based on the total mass of the CMP polishing liquid, from the viewpoint of easily obtaining an effect of improving the polishing rate according to the content. The following is more preferable, 20% by mass or less is further preferable, 17.5% by mass or less is particularly preferable, and 15% by mass or less is extremely preferable. From the above viewpoint, the content of abrasive grains is preferably 1 to 30% by mass.
（酸化剤）
　本実施形態に係るＣＭＰ用研磨液は酸化剤を含む。酸化剤を含有しない研磨液を用いると、例えばＡｌ－Ｍｇ－Ｓｉ系合金（６０００系合金）の一種であるＡ６０６３合金を研磨した際、比較的大きな凹凸が生じる。この凹凸は、合金表面において、Ｍｇ、Ｓｉ、Ｆｅ等の元素が周辺のアルミニウム部分（固溶相）に比べて多く含まれた部分（不純物析出相）の研磨速度が、固溶相の研磨速度に比べ遅いことによって生じると考えられる。一方、酸化剤を用いた研磨液では、凹凸の小さな研磨後表面が得られ、合金の研磨速度が向上する。この原因は明確ではないが、合金表面における固溶相と不純物析出相の両方に酸化剤が同程度に作用するためと考えられる。 (Oxidant)
The polishing slurry for CMP according to this embodiment contains an oxidizing agent. When a polishing liquid that does not contain an oxidizing agent is used, for example, when an A6063 alloy, which is a kind of Al—Mg—Si alloy (6000 alloy), is polished, relatively large irregularities are generated. This unevenness is caused by the polishing rate of the portion (impurity precipitated phase) containing more elements such as Mg, Si, Fe, etc. on the alloy surface than the surrounding aluminum portion (solid solution phase). It is thought that it is caused by being slower than On the other hand, in the polishing liquid using an oxidizing agent, a polished surface with small irregularities is obtained, and the polishing rate of the alloy is improved. The reason for this is not clear, but it is thought that the oxidizing agent acts to the same extent on both the solid solution phase and the impurity precipitation phase on the alloy surface.
　酸化剤としては、過酸化水素、過硫酸塩（例えば、過硫酸アンモニウム、過硫酸ナトリウム、過硫酸カリウム）、硝酸、過ヨウ素酸塩（例えば、過ヨウ素酸アンモニウム、過ヨウ素酸ナトリウム、過ヨウ素酸カリウム）、次亜塩素酸、オゾン水等が挙げられ、中でも、過酸化水素が好ましい。酸化剤としては、一種を単独で用いてもよく、二種以上を混合して用いてもよい。過酸化水素は、通常、過酸化水素水として入手できるため、ＣＭＰ用研磨液の希釈液として使用できる。 Examples of oxidizing agents include hydrogen peroxide, persulfates (eg, ammonium persulfate, sodium persulfate, potassium persulfate), nitric acid, periodate (eg, ammonium periodate, sodium periodate, potassium periodate) ), Hypochlorous acid, ozone water, etc., among which hydrogen peroxide is preferred. As an oxidizing agent, 1 type may be used independently and 2 or more types may be mixed and used. Since hydrogen peroxide is usually available as hydrogen peroxide water, it can be used as a diluent for polishing liquid for CMP.
　酸化剤の含有量は、アルミニウム系材料（例えばアルミニウム合金）の表面の凹凸を更に効果的に解消する観点、及び、アルミニウム系材料（例えばアルミニウム合金）の酸化が不充分となって研磨速度が低下することを防ぐ観点から、ＣＭＰ用研磨液の全質量を基準として、０．０１質量％以上が好ましく、０．０２質量％以上がより好ましく、０．０５質量％以上が更に好ましい。酸化剤の含有量は、研磨速度に更に優れる観点から、ＣＭＰ用研磨液の全質量を基準として、０．１０質量％以上が好ましく、０．２０質量％以上がより好ましく、０．３０質量％以上が更に好ましい。酸化剤の含有量は、被研磨面に荒れ又は研磨傷が生じることを防ぐ観点から、５０質量％以下が好ましく、３０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い。なお、酸化剤として過酸化水素水を使用してもよい。この場合、過酸化水素が最終的に前記範囲になるように換算して過酸化水素水を配合する。 The content of the oxidizing agent is effective in eliminating unevenness on the surface of the aluminum-based material (for example, aluminum alloy), and the polishing rate is lowered due to insufficient oxidation of the aluminum-based material (for example, aluminum alloy). From the viewpoint of preventing this, it is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and still more preferably 0.05% by mass or more, based on the total mass of the polishing slurry for CMP. The content of the oxidizing agent is preferably 0.10% by mass or more, more preferably 0.20% by mass or more, and 0.30% by mass based on the total mass of the polishing slurry for CMP from the viewpoint of further improving the polishing rate. The above is more preferable. The content of the oxidizing agent is preferably 50% by mass or less, more preferably 30% by mass or less, still more preferably 10% by mass or less, and further preferably 5% by mass or less, from the viewpoint of preventing the surface to be polished from being rough or causing scratches. Is particularly preferable, and 3% by mass or less is very preferable. In addition, you may use hydrogen peroxide solution as an oxidizing agent. In this case, the hydrogen peroxide solution is blended so that the hydrogen peroxide finally becomes within the above range.
（液状媒体）
　本実施形態に係るＣＭＰ用研磨液は、砥粒を分散させるための液状媒体を含む。液状媒体としては、公知の液状媒体である水及び有機溶媒を広く使用できる。砥粒を分散できる液体であれば、液状媒体は特に制限されない。但し、ｐＨ調整の容易性、安全性、被研磨面との反応性等の観点から、液状媒体は水を主成分とすることが好ましい。液状媒体としては、脱イオン水、イオン交換水、超純水等が好ましい。液状媒体として用いることができる有機溶媒としては、特に制限はないが、水と任意に混合できる溶媒が好ましい。具体的な有機溶媒としては、酢酸、グリコール類、グリコールモノエーテル類、グリコールジエーテル類、アルコール類、炭酸エステル類、ラクトン類、エーテル類、ケトン類、フェノール、ジメチルホルムアミド、ｎ－メチルピロリドン、酢酸エチル、乳酸エチル、スルホラン等が挙げられる。液状媒体は、一種を単独で用いてもよく、二種以上を混合して用いてもよい。 (Liquid medium)
The CMP polishing liquid according to this embodiment includes a liquid medium for dispersing abrasive grains. As the liquid medium, water and organic solvents which are known liquid media can be widely used. The liquid medium is not particularly limited as long as it can disperse the abrasive grains. However, from the viewpoint of ease of pH adjustment, safety, reactivity with the surface to be polished, etc., the liquid medium preferably contains water as a main component. As the liquid medium, deionized water, ion exchange water, ultrapure water, or the like is preferable. The organic solvent that can be used as the liquid medium is not particularly limited, but a solvent that can be arbitrarily mixed with water is preferable. Specific organic solvents include acetic acid, glycols, glycol monoethers, glycol diethers, alcohols, carbonates, lactones, ethers, ketones, phenol, dimethylformamide, n-methylpyrrolidone, acetic acid Examples include ethyl, ethyl lactate, and sulfolane. A liquid medium may be used individually by 1 type, and 2 or more types may be mixed and used for it.
（ｐＨ）
　本実施形態に係るＣＭＰ用研磨液のｐＨは、１１．５以下である。なお、ｐＨは液温２５℃におけるｐＨと定義する。ｐＨが１１．５以下であると、アルミニウム系材料の基体の腐食と、それに起因する表面粗さの増大を抑制できる。ｐＨは、表面粗さが増大することが抑制されやすい観点から、１１．０以下が好ましく、１０．５以下がより好ましく、１０．３以下が更に好ましい。 (PH)
The polishing slurry for CMP according to this embodiment has a pH of 11.5 or less. The pH is defined as the pH at a liquid temperature of 25 ° C. When the pH is 11.5 or less, corrosion of the aluminum-based material substrate and increase in surface roughness due to the corrosion can be suppressed. The pH is preferably 11.0 or less, more preferably 10.5 or less, and even more preferably 10.3 or less, from the viewpoint of easily suppressing an increase in surface roughness.
　本実施形態に係るＣＭＰ用研磨液のｐＨは、アルミニウム系材料の研磨速度が向上しやすい観点から、７．０以上が好ましく、７．５以上がより好ましく、８．０以上が更に好ましく、８．５以上が特に好ましく、９．０以上が極めて好ましい。 The pH of the polishing slurry for CMP according to this embodiment is preferably 7.0 or more, more preferably 7.5 or more, still more preferably 8.0 or more, from the viewpoint of easily improving the polishing rate of the aluminum-based material. .5 or more is particularly preferable, and 9.0 or more is extremely preferable.
　ＣＭＰ用研磨液のｐＨは、硫酸、塩酸、リン酸等の酸成分；アンモニア、水酸化ナトリウム、水酸化カリウム、ＴＭＡＨ（水酸化テトラメチルアンモニウム）、イミダゾール等のアルカリ成分などによって調整可能である。また、ｐＨを安定化させるため、ＣＭＰ用研磨液に緩衝液を添加してもよい。このような緩衝液としては、例えば、酢酸塩緩衝液及びフタル酸塩緩衝液が挙げられる。 The pH of the polishing slurry for CMP can be adjusted by acid components such as sulfuric acid, hydrochloric acid, and phosphoric acid; alkaline components such as ammonia, sodium hydroxide, potassium hydroxide, TMAH (tetramethylammonium hydroxide), and imidazole. In order to stabilize the pH, a buffer solution may be added to the CMP polishing solution. Examples of such a buffer include an acetate buffer and a phthalate buffer.
　ＣＭＰ用研磨液のｐＨは、ｐＨメーター（例えば、電気化学計器株式会社製、型番：ＰＨＬ－４０）で測定できる。ｐＨの測定値としては、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、２分以上経過して安定した後の値を採用できる。 The pH of the polishing slurry for CMP can be measured with a pH meter (for example, model number: PHL-40, manufactured by Electrochemical Instrument Co., Ltd.). As the measured value of pH, standard buffer solution (phthalate pH buffer solution pH: 4.01 (25 ° C), neutral phosphate pH buffer solution pH: 6.86 (25 ° C), borate pH buffer solution After calibrating three points using the solution pH: 9.18 (25 ° C.), the value after the electrode has been put into the CMP polishing solution and stabilized for 2 minutes or more can be adopted.
　本実施形態に係るＣＭＰ用研磨液は、界面活性剤等を含有できる。 The CMP polishing liquid according to this embodiment can contain a surfactant or the like.
［貯蔵液］
　本実施形態に係るＣＭＰ用研磨液は、貯蔵、運搬、保管等に係るコストを抑制する観点から、使用時に水等の液状媒体で希釈されて使用される貯蔵液として保管できる。本実施形態に係る貯蔵液は、ＣＭＰ用研磨液を得るための貯蔵液であり、液状媒体で希釈する（例えば、質量基準で２倍以上に希釈する）ことによりＣＭＰ用研磨液が得られる。本実施形態では、研磨の直前に液状媒体で貯蔵液を希釈してＣＭＰ用研磨液を調製してもよい。また、プラテン（研磨定盤）上に貯蔵液と液状媒体を供給し、プラテン上でＣＭＰ用研磨液を調製してもよい。また、酸化剤を貯蔵液に配合せず、使用時にこれらを添加してもよい。 [Stock solution]
The CMP polishing liquid according to the present embodiment can be stored as a storage liquid used by being diluted with a liquid medium such as water at the time of use from the viewpoint of suppressing costs related to storage, transportation, storage and the like. The storage liquid according to the present embodiment is a storage liquid for obtaining a CMP polishing liquid, and the CMP polishing liquid is obtained by diluting with a liquid medium (for example, diluting twice or more on a mass basis). In the present embodiment, a CMP polishing liquid may be prepared by diluting a storage liquid with a liquid medium immediately before polishing. Further, a storage liquid and a liquid medium may be supplied on a platen (polishing surface plate) to prepare a CMP polishing liquid on the platen. Moreover, you may add these at the time of use, without mix | blending an oxidizing agent with a stock solution.
　貯蔵液の希釈倍率（質量基準）の下限としては、倍率が高いほど貯蔵、運搬、保管等に係るコストの抑制効果が高い観点から、２倍以上が好ましく、３倍以上がより好ましい。希釈倍率の上限としては、特に制限はないが、１０倍以下が好ましく、７倍以下がより好ましく、５倍以下が更に好ましい。このような希釈倍率の上限値である場合、貯蔵液に含まれる成分（酸及び酸化剤等の化学成分、砥粒など）の含有量が高くなり過ぎることが抑制され、保管中の貯蔵液の安定性を維持しやすい傾向がある。なお、希釈倍率がｄ倍であるとき、貯蔵液中に含まれる成分の含有量は、ＣＭＰ用研磨液中に含まれる成分の含有量のｄ倍である。 The lower limit of the dilution ratio (mass basis) of the stock solution is preferably 2 times or more and more preferably 3 times or more from the viewpoint that the higher the magnification is, the higher the effect of suppressing costs related to storage, transportation, storage and the like. Although there is no restriction | limiting in particular as an upper limit of a dilution rate, 10 times or less are preferable, 7 times or less are more preferable, and 5 times or less are still more preferable. When the upper limit of the dilution ratio is such that the content of components (chemical components such as acids and oxidizing agents, abrasive grains, etc.) contained in the stock solution is prevented from becoming too high, There is a tendency to maintain stability. When the dilution rate is d times, the content of the components contained in the storage liquid is d times the content of the components contained in the CMP polishing liquid.
［アルミニウム系材料を含む基体］
　本実施形態に係るＣＭＰ用研磨液は、アルミニウム系材料を少なくとも含む基体のＣＭＰに適している。アルミニウム系材料としては、純アルミニウム（１０００系）；Ａｌ－Ｃｕ（２０００系）、Ａｌ－Ｍｎ（３０００系）、Ａｌ－Ｓｉ（４０００系）、Ａｌ－Ｍｇ（５０００系）、Ａｌ－Ｍｇ－Ｓｉ（６０００系）、Ａｌ－Ｚｎ－Ｍｇ（７０００系）等のアルミニウム合金などが挙げられる。なお、純アルミニウムとは、意図的に異種元素を添加していないアルミニウムをいう。これらのアルミニウム系材料の名称は、日本工業規格（ＪＩＳ）又は国際アルミニウム合金名に準じるものである。 [Substrate containing aluminum-based material]
The polishing slurry for CMP according to this embodiment is suitable for CMP of a substrate containing at least an aluminum-based material. As aluminum materials, pure aluminum (1000 series); Al—Cu (2000 series), Al—Mn (3000 series), Al—Si (4000 series), Al—Mg (5000 series), Al—Mg—Si (6000 series), Al-Zn-Mg (7000 series) and other aluminum alloys. Pure aluminum refers to aluminum to which a different element is not intentionally added. The names of these aluminum-based materials conform to Japanese Industrial Standards (JIS) or international aluminum alloy names.
　また、本実施形態に係るＣＭＰ用研磨液は、純アルミニウムよりも硬い部分を有するアルミニウム合金の研磨に適している。純アルミニウムよりも硬い部分を有するアルミニウム合金の具体例としては、Ａｌ－Ｃｕ（２０００系）、Ａｌ－Ｍｎ（３０００系）、Ａｌ－Ｓｉ（４０００系）、Ａｌ－Ｍｇ（５０００系）、Ａｌ－Ｍｇ－Ｓｉ（６０００系）、Ａｌ－Ｚｎ－Ｍｇ（７０００系）等が挙げられる。これらの中でも、本実施形態に係るＣＭＰ用研磨液の特性を活かしやすい観点から、Ａｌ－Ｍｇ－Ｓｉ（Ａ６０６３系）又はＡｌ－Ｍｇ（Ａ５０５２）等が好ましい。 Further, the CMP polishing liquid according to the present embodiment is suitable for polishing an aluminum alloy having a harder portion than pure aluminum. Specific examples of aluminum alloys having parts harder than pure aluminum include Al—Cu (2000 series), Al—Mn (3000 series), Al—Si (4000 series), Al—Mg (5000 series), Al— Mg-Si (6000 series), Al-Zn-Mg (7000 series) and the like can be mentioned. Among these, Al—Mg—Si (A6063 series) or Al—Mg (A5052) is preferable from the viewpoint of easily utilizing the characteristics of the polishing slurry for CMP according to the present embodiment.
　アルミニウム系材料を含む基体としては、特に制限はないが、半導体基板等の基板、航空機部品、自動車部品等の部品、鉄道車両等の車両、電子機器（携帯型電子機器等）の筐体などが挙げられる。本実施形態に係るＣＭＰ用研磨液を用いた研磨によれば、前記アルミニウム系材料（例えばアルミニウム合金）を含む基体の表面を充分に平滑に研磨できる。このような研磨によって、美しい白銀色を呈する基体の表面が得られる。また、このような表面に塗装等の着色処理を行った場合においても、美しい外観が得られる。したがって、本実施形態に係るＣＭＰ用研磨液は、美しい外観が要求される基体（例えば筐体）の研磨に特に好適である。 The substrate containing an aluminum-based material is not particularly limited, but may be a substrate such as a semiconductor substrate, a part such as an aircraft part or an automobile part, a vehicle such as a railway vehicle, a case of an electronic device (such as a portable electronic device). Can be mentioned. According to the polishing using the CMP polishing liquid according to the present embodiment, the surface of the substrate containing the aluminum-based material (for example, an aluminum alloy) can be polished sufficiently smoothly. By such polishing, a surface of a substrate exhibiting a beautiful white silver color is obtained. Moreover, a beautiful appearance can be obtained even when such a surface is subjected to a coloring treatment such as painting. Therefore, the CMP polishing liquid according to this embodiment is particularly suitable for polishing a substrate (for example, a casing) that requires a beautiful appearance.
　本実施形態に係るＣＭＰ用研磨液は、例えば、研磨前における表面粗さ（Ｒａ）が５．０ｎｍ以上である基体を、研磨後における表面粗さ（Ｒａ）が４．０ｎｍ以下となるように研磨するために用いられてもよい。基体の表面粗さ（Ｒａ）は、平滑な表面が得られやすい観点から、研磨前において２０．０ｎｍ未満が好ましく、１５．０ｎｍ未満がより好ましく、１０．０ｎｍ未満が更に好ましい。また、基体の表面粗さ（Ｒａ）は、研磨前において５．０ｎｍ以上が好ましく、６．０ｎｍ以上がより好ましく、７．０ｎｍ以上が更に好ましい。 In the polishing slurry for CMP according to this embodiment, for example, a substrate having a surface roughness (Ra) before polishing of 5.0 nm or more and a surface roughness (Ra) after polishing of 4.0 nm or less are used. It may be used for polishing. The surface roughness (Ra) of the substrate is preferably less than 20.0 nm, more preferably less than 15.0 nm, and even more preferably less than 10.0 nm before polishing from the viewpoint of easily obtaining a smooth surface. In addition, the surface roughness (Ra) of the substrate is preferably 5.0 nm or more, more preferably 6.0 nm or more, and even more preferably 7.0 nm or more before polishing.
［研磨方法］
　本実施形態に係る研磨方法は、ＣＭＰ用研磨液を用いて、アルミニウム系材料を含む基体を研磨する研磨工程を備えていてもよく、貯蔵液を液状媒体で希釈する（例えば質量基準で２倍以上に希釈する）ことにより得られるＣＭＰ用研磨液を用いて、アルミニウム系材料を含む基体を研磨する研磨工程を備えていてもよい。 [Polishing method]
The polishing method according to the present embodiment may include a polishing step of polishing a substrate containing an aluminum-based material using a CMP polishing liquid, and dilute the storage liquid with a liquid medium (for example, twice on a mass basis). A polishing step for polishing a substrate containing an aluminum-based material using a polishing slurry for CMP obtained by diluting as described above may be provided.
　研磨工程において、基体の研磨前における表面粗さ（Ｒａ）は例えば５．０ｎｍ以上であり、基体の研磨後における表面粗さ（Ｒａ）は例えば４．０ｎｍ以下である。すなわち、研磨工程は、例えば、ＣＭＰ用研磨液を用いて、５．０ｎｍ以上の表面粗さ（Ｒａ）を有する基体を研磨して、４．０ｎｍ以下の表面粗さ（Ｒａ）を有する基体を得る工程であってもよい。基体の表面粗さ（Ｒａ）は、平滑な表面が得られやすい観点から、研磨前において２０．０ｎｍ未満が好ましく、１５．０ｎｍ未満がより好ましく、１０．０ｎｍ未満が更に好ましい。また、基体の表面粗さ（Ｒａ）は、研磨前において５．０ｎｍ以上が好ましく、６．０ｎｍ以上がより好ましく、７．０ｎｍ以上が更に好ましい。 In the polishing step, the surface roughness (Ra) before polishing of the substrate is, for example, 5.0 nm or more, and the surface roughness (Ra) after polishing of the substrate is, for example, 4.0 nm or less. That is, in the polishing step, for example, a substrate having a surface roughness (Ra) of 5.0 nm or more is polished by using a CMP polishing liquid to obtain a substrate having a surface roughness (Ra) of 4.0 nm or less. It may be a step of obtaining. The surface roughness (Ra) of the substrate is preferably less than 20.0 nm, more preferably less than 15.0 nm, and even more preferably less than 10.0 nm before polishing from the viewpoint of easily obtaining a smooth surface. In addition, the surface roughness (Ra) of the substrate is preferably 5.0 nm or more, more preferably 6.0 nm or more, and even more preferably 7.0 nm or more before polishing.
　本実施形態に係る研磨方法では、公知の研磨装置を広く用いることができる。例えば、研磨装置としては、基体を保持するホルダーと、研磨パッド（研磨布）を貼り付けたプラテンとを有する一般的な研磨装置が挙げられる。プラテンには、例えば、プラテンの回転数を変更するためのモータ等が取り付けられていてもよい。 In the polishing method according to this embodiment, a known polishing apparatus can be widely used. For example, as a polishing apparatus, a general polishing apparatus having a holder for holding a substrate and a platen on which a polishing pad (polishing cloth) is attached can be mentioned. For example, a motor or the like for changing the rotation speed of the platen may be attached to the platen.
　研磨パッドとしては、特に限定されないが、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挙げられる。これらの研磨パッドの表面には、ＣＭＰ用研磨液が溜まるような溝が形成されていることが好ましい。基体の研磨条件に制限はないが、基体の飛び出しを防止しやすい観点から、プラテンの回転数は２００ｍｉｎ－１以下であることが好ましい。研磨後の基体表面における傷の発生を抑制しやすい観点から、研磨荷重は３４．５ｋＰａ（５ｐｓｉ）以下であることが好ましい。 Although it does not specifically limit as a polishing pad, A general nonwoven fabric, a polyurethane foam, a porous fluororesin, etc. are mentioned. It is preferable that a groove is formed on the surface of these polishing pads so that the polishing liquid for CMP is accumulated. The polishing conditions for the substrate are not limited, but from the viewpoint of easily preventing the substrate from popping out, the platen rotation speed is preferably 200 min −1 or less. The polishing load is preferably 34.5 kPa (5 psi) or less from the viewpoint of easily suppressing the occurrence of scratches on the substrate surface after polishing.
　本実施形態に係る研磨方法では、例えば、プラテンに貼り付けられた研磨パッドに、アルミニウム系材料を含む基体を押圧した状態で、ＣＭＰ用研磨液を基体と研磨パッドとの間にポンプ等により供給し、基体とプラテンとを相対的に動かす。これらの操作により、基体表面に対する化学機械研磨を行うことができる。ＣＭＰ用研磨液を研磨装置に供給する方法は、研磨の間、ＣＭＰ用研磨液を研磨パッドに連続的に供給できるものであれば、特に限定されない。ＣＭＰ用研磨液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。貯蔵液と、水等の液状媒体とを基体と研磨パッドとの間に供給し、プラテン上で貯蔵液を希釈（例えば質量基準で２倍以上に希釈）しながら研磨を行ってもよい。 In the polishing method according to the present embodiment, for example, a CMP polishing liquid is supplied between the substrate and the polishing pad by a pump or the like in a state where the substrate including the aluminum-based material is pressed against the polishing pad attached to the platen. Then, the base and the platen are moved relative to each other. By these operations, chemical mechanical polishing can be performed on the substrate surface. The method for supplying the CMP polishing liquid to the polishing apparatus is not particularly limited as long as the CMP polishing liquid can be continuously supplied to the polishing pad during polishing. The supply amount of the polishing liquid for CMP is not limited, but it is preferable that the surface of the polishing pad is always covered with the polishing liquid for CMP. Polishing may be performed while supplying a storage liquid and a liquid medium such as water between the substrate and the polishing pad, and diluting the storage liquid on the platen (for example, diluting it twice or more on a mass basis).
　研磨終了後の基体は、水、エタノール、イソプロピルアルコール等で洗浄後、基体上に付着した液滴（例えば水滴）をスピンドライヤ等により払い落としてから乾燥させることが好ましい。 The substrate after polishing is preferably washed with water, ethanol, isopropyl alcohol, or the like, and then dried after removing droplets (for example, water droplets) adhering to the substrate with a spin dryer or the like.
　以下、実施例により本発明を更に詳しく説明するが、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制限されるものではない。なお、ｐＨの測定は、電気化学計器株式会社製、型番：ＰＨＬ－４０を用いて行った。 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples without departing from the technical idea of the present invention. The pH was measured using a model number: PHL-40, manufactured by Electrochemical Instrument Co., Ltd.
＜砥粒の一次粒径、円形度、真球度の測定＞
　以下の手順で、市販のコロイダルシリカＡ～Ｈ（砥粒）を走査型電子顕微鏡で観察し、一次粒径、円形度及び真球度を測定した。 <Measurement of primary particle size, circularity and sphericity of abrasive grains>
In the following procedure, commercially available colloidal silicas A to H (abrasive grains) were observed with a scanning electron microscope, and the primary particle size, circularity and sphericity were measured.
　まず、測定対象の砥粒を含む液体を適量容器に測り取った。次に、パターン配線付きウエハを２ｃｍ角に切って得られたチップを、容器中の液体に約３０秒浸した。そして、脱イオン水の入った容器にチップを移して、約３０秒間すすぎをし、チップを窒素ブロー乾燥した。その後、走査型電子顕微鏡観察用の試料台にチップを載せ、加速電圧１０ｋＶで適切な倍率（例えば２０万倍）にて粒子を観察すると共に、投影画像を撮影した。 First, an appropriate amount of liquid containing abrasive grains to be measured was measured in a container. Next, the chip obtained by cutting the wafer with pattern wiring into 2 cm square was immersed in the liquid in the container for about 30 seconds. Then, the chip was transferred to a container containing deionized water, rinsed for about 30 seconds, and the chip was blown with nitrogen. Thereafter, the chip was placed on a sample stage for scanning electron microscope observation, and particles were observed at an appropriate magnification (for example, 200,000 times) with an acceleration voltage of 10 kV, and a projected image was taken.
　得られた投影画像から任意の８０個の粒子を選択した。次に、選択した粒子が例えば図２に示すような形状であった場合、測定粒子１に外接する長方形（外接長方形）２を、長方形２の長径の長さＤＬが最も長くなるように導いた。そして、長方形２の長径の長さＤＬ、及び、長径に直交する短径の長さＤＳに基づき、二軸平均粒径（√（ＤＬ×ＤＳ））を各粒子について算出した。この作業を任意の８０個の粒子に対して実施し、得られた値を平均して一次粒径を得た。 Arbitrary 80 particles were selected from the obtained projection image. Next, when the selected particle has a shape as shown in FIG. 2, for example, the rectangle (circumscribed rectangle) 2 circumscribing the measurement particle 1 is guided so that the length DL of the major axis of the rectangle 2 becomes the longest. . The biaxial average particle diameter (√ (DL × DS)) was calculated for each particle on the basis of the length DL of the major axis of the rectangle 2 and the length DS of the minor axis orthogonal to the major axis. This operation was performed on arbitrary 80 particles, and the obtained values were averaged to obtain a primary particle size.
　また、投影画像における粒子の面積Ｓ及び周囲長Ｌを求めた。次に、投影画像における測定粒子１の面積Ｓと同一の面積を有する真円１ａ（図１）の周囲長（外周）Ｌ’を求めた後、周囲長Ｌに対する周囲長Ｌ’の比（Ｌ’／Ｌ）を算出した。この作業を任意の８０個の粒子に対して実施し、得られた値を平均して円形度を得た。 Further, the area S and the perimeter L of the particle in the projection image were obtained. Next, after obtaining the peripheral length (outer periphery) L ′ of the perfect circle 1a (FIG. 1) having the same area as the area S of the measurement particle 1 in the projection image, the ratio of the peripheral length L ′ to the peripheral length L (L '/ L) was calculated. This operation was performed on arbitrary 80 particles, and the obtained values were averaged to obtain the circularity.
　さらに、長径の長さＤＬに対する短径の長さＤＳの比（ＤＳ／ＤＬ）を任意の８０個の粒子について取得し、その値を平均して真球度を得た。 Furthermore, the ratio of the length DS of the short diameter to the length DL of the long diameter (DS / DL) was obtained for any 80 particles, and the values were averaged to obtain the sphericity.
　投影画像における粒子の前記面積Ｓ及び前記周囲長Ｌは、画像解析ソフト（アメリカ国立衛生研究所製、ＩｍａｇｅＪ）を用いて測定した。 The area S and the perimeter L of the particles in the projected image were measured using image analysis software (ImageJ, manufactured by National Institutes of Health).
　一次粒径、円形度及び真球度の測定結果を表１に示す。 Table 1 shows the measurement results of primary particle size, circularity and sphericity.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
＜実験１：コロイダルシリカの円形度の影響＞
（実施例１）
　脱イオン水にコロイダルシリカＡを添加した後、３０質量％過酸化水素水を添加し、実施例１のＣＭＰ用研磨液１に対応する貯蔵液１を作製した。この貯蔵液１の調製工程では、コロイダルシリカＡの含有量が貯蔵液１の全質量を基準として３０質量％であり、且つ、過酸化水素の含有量が貯蔵液１の全質量を基準として０．６０質量％（３０質量％過酸化水素水換算で２．００質量％）であるように、コロイダルシリカＡ及び過酸化水素水を添加して貯蔵液１を調製した。 <Experiment 1: Effect of circularity of colloidal silica>
(Example 1)
After adding colloidal silica A to deionized water, 30 mass% hydrogen peroxide water was added to prepare a stock solution 1 corresponding to the polishing slurry 1 for CMP of Example 1. In the process of preparing the stock solution 1, the content of colloidal silica A is 30% by mass based on the total mass of the stock solution 1, and the content of hydrogen peroxide is 0 based on the total mass of the stock solution 1. Colloidal silica A and hydrogen peroxide solution were added to prepare storage solution 1 so as to be .60% by mass (2.00% by mass in terms of 30% by mass hydrogen peroxide solution).
　貯蔵液１を水で２倍に希釈する（貯蔵液を、貯蔵液と同質量の脱イオン水と混合する）ことによって、研磨液１を調製した。すなわち、研磨液１において、コロイダルシリカＡの含有量は研磨液１の全質量を基準として１５質量％であり、過酸化水素の含有量は研磨液１の全質量を基準として０．３０質量％であった。研磨液１のｐＨは水酸化カリウムで１０．０に調整した。 Polishing liquid 1 was prepared by diluting the storage liquid 1 with water twice (mixing the storage liquid with deionized water having the same mass as the storage liquid). That is, in the polishing liquid 1, the content of colloidal silica A is 15% by mass based on the total mass of the polishing liquid 1, and the hydrogen peroxide content is 0.30% by mass based on the total mass of the polishing liquid 1. Met. The pH of the polishing liquid 1 was adjusted to 10.0 with potassium hydroxide.
（実施例２）
　実施例２では、砥粒としてコロイダルシリカＢを添加した以外は実施例１と同様に実験を行い、貯蔵液２及び研磨液２を作製した。研磨液２のｐＨは水酸化カリウムで１０．０に調整した。 (Example 2)
In Example 2, an experiment was performed in the same manner as in Example 1 except that colloidal silica B was added as abrasive grains, and a stock solution 2 and a polishing solution 2 were produced. The pH of the polishing liquid 2 was adjusted to 10.0 with potassium hydroxide.
（実施例３）
　実施例３では、砥粒としてコロイダルシリカＡ及びコロイダルシリカＧを等量ずつ添加した以外は実施例１と同様に実験を行った。すなわち、脱イオン水にコロイダルシリカＡとコロイダルシリカＧを添加した後、３０質量％過酸化水素水を添加し、ＣＭＰ用研磨液３に対応する貯蔵液３を作製した。この貯蔵液３の調製工程では、コロイダルシリカＡの含有量が貯蔵液３の全質量を基準として１５質量％であり、且つ、コロイダルシリカＧの含有量が貯蔵液３の全質量を基準として１５質量％であり、且つ、過酸化水素の含有量が貯蔵液３の全質量を基準として０．６０質量％（３０質量％過酸化水素水換算で２．００質量％）であるように、コロイダルシリカＡ、コロイダルシリカＧ及び過酸化水素水を添加して貯蔵液３を調製した。その後は、実施例１と同様の手順で研磨液３を調製した。すなわち、研磨液３において、コロイダルシリカＡ及びコロイダルシリカＧの含有量は研磨液３の全質量を基準としてそれぞれ７．５質量％であり、過酸化水素の含有量は研磨液３の全質量を基準として０．３０質量％であった。研磨液３のｐＨは水酸化カリウムで１０．０に調整した。 (Example 3)
In Example 3, an experiment was performed in the same manner as in Example 1 except that equal amounts of colloidal silica A and colloidal silica G were added as abrasive grains. That is, after adding colloidal silica A and colloidal silica G to deionized water, 30 mass% hydrogen peroxide water was added to prepare a stock solution 3 corresponding to the polishing slurry 3 for CMP. In the process of preparing the stock solution 3, the content of colloidal silica A is 15% by mass based on the total mass of the stock solution 3, and the content of colloidal silica G is 15 based on the total mass of the stock solution 3. Colloidal so that the content of hydrogen peroxide is 0.60% by mass (2.00% by mass in terms of 30% by mass hydrogen peroxide) based on the total mass of the storage liquid 3. Stock solution 3 was prepared by adding silica A, colloidal silica G and hydrogen peroxide. Thereafter, a polishing liquid 3 was prepared in the same procedure as in Example 1. That is, in the polishing liquid 3, the contents of the colloidal silica A and the colloidal silica G are each 7.5% by mass based on the total mass of the polishing liquid 3, and the content of hydrogen peroxide is the total mass of the polishing liquid 3. The standard was 0.30% by mass. The pH of the polishing liquid 3 was adjusted to 10.0 with potassium hydroxide.
（比較例１）
　比較例１では、砥粒としてコロイダルシリカＣを添加した以外は実施例１と同様に実験を行い、貯蔵液１Ｘ及び研磨液１Ｘを作製した。研磨液１ＸのｐＨは水酸化カリウムで１０．０に調整した。 (Comparative Example 1)
In Comparative Example 1, an experiment was performed in the same manner as in Example 1 except that colloidal silica C was added as abrasive grains, and a storage liquid 1X and a polishing liquid 1X were produced. The pH of the polishing liquid 1X was adjusted to 10.0 with potassium hydroxide.
（比較例２）
　比較例２では、砥粒としてコロイダルシリカＤを添加した以外は実施例１と同様に実験を行い、貯蔵液２Ｘ及び研磨液２Ｘを作製した。研磨液２ＸのｐＨは水酸化カリウムで１０．０に調整した。 (Comparative Example 2)
In Comparative Example 2, an experiment was performed in the same manner as in Example 1 except that colloidal silica D was added as abrasive grains, and a stock solution 2X and a polishing solution 2X were produced. The pH of the polishing liquid 2X was adjusted to 10.0 with potassium hydroxide.
（比較例３）
　比較例３では、砥粒としてコロイダルシリカＥを添加した以外は実施例１と同様に実験を行い、貯蔵液３Ｘ及び研磨液３Ｘを作製した。研磨液３ＸのｐＨは水酸化カリウムで１０．０に調整した。 (Comparative Example 3)
In Comparative Example 3, an experiment was performed in the same manner as in Example 1 except that colloidal silica E was added as abrasive grains, and a stock solution 3X and a polishing solution 3X were produced. The pH of the polishing liquid 3X was adjusted to 10.0 with potassium hydroxide.
（比較例４）
　比較例４では、砥粒としてコロイダルシリカＦを添加した以外は実施例１と同様に実験を行い、貯蔵液４Ｘ及び研磨液４Ｘを作製した。研磨液４ＸのｐＨは水酸化カリウムで１０．０に調整した。 (Comparative Example 4)
In Comparative Example 4, an experiment was performed in the same manner as in Example 1 except that colloidal silica F was added as abrasive grains, and a storage liquid 4X and a polishing liquid 4X were produced. The pH of the polishing liquid 4X was adjusted to 10.0 with potassium hydroxide.
（比較例５）
　比較例５では、砥粒としてコロイダルシリカＧを添加した以外は実施例１と同様に実験を行い、貯蔵液５Ｘ及び研磨液５Ｘを作製した。研磨液５ＸのｐＨは水酸化カリウムで１０．０に調整した。 (Comparative Example 5)
In Comparative Example 5, an experiment was performed in the same manner as in Example 1 except that colloidal silica G was added as abrasive grains, and a stock solution 5X and a polishing solution 5X were produced. The pH of the polishing liquid 5X was adjusted to 10.0 with potassium hydroxide.
（比較例６）
　比較例６では、砥粒としてコロイダルシリカＨを添加した以外は実施例１と同様に実験を行い、貯蔵液６Ｘ及び研磨液６Ｘを作製した。研磨液６ＸのｐＨは水酸化カリウムで１０．０に調整した。 (Comparative Example 6)
In Comparative Example 6, an experiment was performed in the same manner as in Example 1 except that colloidal silica H was added as abrasive grains, and a storage liquid 6X and a polishing liquid 6X were produced. The pH of the polishing liquid 6X was adjusted to 10.0 with potassium hydroxide.
　以上の手順で、研磨液の全質量を基準として、砥粒を１５質量％、酸化剤を０．３０質量％含む研磨液１～３及び研磨液１Ｘ～６Ｘを作製した。 By the above procedure, polishing liquids 1 to 3 and polishing liquids 1X to 6X containing 15% by mass of abrasive grains and 0.30% by mass of an oxidizing agent were prepared based on the total mass of the polishing liquid.
［ＣＭＰ方法及び研磨特性の評価方法］
　以下の手順で、研磨装置を用いてＣＭＰ用研磨液による基体の化学機械研磨を行った。 [CMP method and polishing characteristic evaluation method]
The substrate was subjected to chemical mechanical polishing with a polishing liquid for CMP using the polishing apparatus in the following procedure.
　プラテンに貼り付けられた研磨パッドに下記の基体を押圧した状態で、ＣＭＰ用研磨液を基体と研磨パッドとの間にポンプにより供給しながら、プラテンを回転させた。これらの操作により、基体表面の化学機械研磨を行った。 The platen was rotated while supplying the CMP polishing liquid between the substrate and the polishing pad with a pump while pressing the following substrate on the polishing pad attached to the platen. By these operations, chemical mechanical polishing of the substrate surface was performed.
　研磨する基体としては、Ａｌ－Ｍｇ－Ｓｉ系合金の板であるＡ６０６３を使用した。基体のサイズは横３０ｍｍ×縦３０ｍｍ×厚さ５ｍｍであった。ＣＭＰ前の板の表面には傷（初期凹凸）があった。この初期凹凸に起因して板の表面は完全に曇っており、充分に物体を映し出すことができない状態であった。 As the substrate to be polished, A6063, which is an Al—Mg—Si alloy plate, was used. The size of the substrate was 30 mm wide × 30 mm long × 5 mm thick. There were scratches (initial irregularities) on the surface of the plate before CMP. Due to the initial unevenness, the surface of the plate was completely cloudy, and the object could not be sufficiently projected.
　研磨装置として、株式会社ナノファクター製の型式ＦＡＣＴ―２００を用いた。研磨パッドとして、独立気泡を有する発泡ポリウレタン樹脂を用いた。研磨条件は以下の通りであった。 As a polishing apparatus, model FACT-200 manufactured by Nano Factor Co., Ltd. was used. A foamed polyurethane resin having closed cells was used as a polishing pad. The polishing conditions were as follows.
（研磨条件）
　研磨荷重：９．０ｋＰａ（１．３ｐｓｉ）
　プラテンの回転数：１５０ｍｉｎ－１（ｒｐｍ）
　ＣＭＰ用研磨液の流量（供給量）：３ｍＬ／ｍｉｎ
　研磨時間：１０ｍｉｎ (Polishing conditions)
Polishing load: 9.0 kPa (1.3 psi)
Platen rotation speed: 150 min -1 (rpm)
Flow rate (supply amount) of polishing liquid for CMP: 3 mL / min
Polishing time: 10 min
（研磨速度）
　各研磨液を用いたＣＭＰ前後の基体の質量を測定することにより、研磨された質量を求めた。基体の被研磨面の面積と密度の値（基体を純アルミニウムと仮定し密度２．７０ｇ／ｃｍ３の値を使用）を用いて、研磨された質量を膜厚に換算し、研磨速度を算出した。実施例１～３及び比較例１～６についての評価結果を表２に示す。 (Polishing speed)
The polished mass was determined by measuring the mass of the substrate before and after CMP using each polishing liquid. Using the surface area and density values of the substrate to be polished (assuming the substrate is pure aluminum and using a density of 2.70 g / cm 3 ), the polished mass is converted into a film thickness and the polishing rate is calculated. did. The evaluation results for Examples 1 to 3 and Comparative Examples 1 to 6 are shown in Table 2.
（ＣＭＰ後基体表面の平均表面粗さ）
　表面粗さをＪＩＳ　Ｂ　０６０１：２００１に準拠して評価した。各研磨液を用いたＣＭＰ後の各基体の平均表面粗さ（Ｒａ）を、非接触表面形状測定機を用いて測定した。非接触表面形状測定機として、走査型白色干渉法を利用したＺｙｇｏ社のＮｅｗＶｉｅｗ７２００を用い、対物レンズ×１０（１０倍）のモードで基体中央を３点測定し、得られた値の平均値をＲａとした。なお、測定範囲は０．７０ｍｍ×０．５３ｍｍ、光源は白色ＬＥＤであった。ＣＭＰ前の基体のＲａは９．４ｎｍであった。実施例１～３及び比較例１～６についての評価結果を表２に示す。 (Average surface roughness of substrate surface after CMP)
The surface roughness was evaluated according to JIS B 0601: 2001. The average surface roughness (Ra) of each substrate after CMP using each polishing liquid was measured using a non-contact surface shape measuring machine. Using Zygo's NewView 7200 using scanning white interferometry as a non-contact surface shape measuring machine, the center of the substrate is measured at three points in the objective lens × 10 (10 times) mode, and the average value of the obtained values is calculated. Ra. The measurement range was 0.70 mm × 0.53 mm, and the light source was a white LED. The Ra of the substrate before CMP was 9.4 nm. The evaluation results for Examples 1 to 3 and Comparative Examples 1 to 6 are shown in Table 2.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
［評価結果］
　表２から明らかなように、円形度が０．９０以下の砥粒を用いることで研磨後の基体の平均表面粗さ（Ｒａ）が良好であり、また、研磨速度も優れていた。一方、円形度が０．９０を超える砥粒のみを用いる場合には、平均表面粗さ（Ｒａ）が不良である結果が得られた。 [Evaluation results]
As is apparent from Table 2, the average surface roughness (Ra) of the substrate after polishing was good by using abrasive grains having a circularity of 0.90 or less, and the polishing rate was also excellent. On the other hand, when only the abrasive grains having a circularity exceeding 0.90 were used, the average surface roughness (Ra) was poor.
　以上の結果より、円形度が０．９０以下の砥粒を用いることで、アルミニウム系材料の表面を高速且つ平滑に研磨できることが確認された。 From the above results, it was confirmed that the surface of the aluminum-based material can be polished smoothly at high speed by using abrasive grains having a circularity of 0.90 or less.
＜実験２：ｐＨの影響＞
（実施例４）
　実施例４では、実施例１と同様に作製した貯蔵液１を水で２倍に希釈し、硫酸でｐＨを７．０に調整することにより研磨液４を作製した。 <Experiment 2: Effect of pH>
Example 4
In Example 4, the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 7.0 with sulfuric acid to prepare the polishing solution 4.
（実施例５）
　実施例５では、実施例１と同様に作製した貯蔵液１を水で２倍に希釈し、硫酸でｐＨを８．０に調整することにより研磨液５を作製した。 (Example 5)
In Example 5, the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 8.0 with sulfuric acid to prepare the polishing solution 5.
（実施例６）
　実施例６では、実施例１と同様に作製した貯蔵液１を水で２倍に希釈し、硫酸でｐＨを９．０に調整することにより研磨液６を作製した。 (Example 6)
In Example 6, the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 9.0 with sulfuric acid to prepare the polishing solution 6.
（実施例７）
　実施例７では、実施例１と同様に作製した貯蔵液１を水で２倍に希釈し、水酸化カリウムでｐＨを１１．０に調整することにより研磨液７を作製した。 (Example 7)
In Example 7, the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 11.0 with potassium hydroxide to prepare the polishing solution 7.
（比較例７）
　比較例７では、実施例１と同様に作製した貯蔵液１を水で２倍に希釈し、水酸化カリウムでｐＨを１２．０に調整することにより研磨液７Ｘを作製した。 (Comparative Example 7)
In Comparative Example 7, the stock solution 1 prepared in the same manner as in Example 1 was diluted twice with water, and the pH was adjusted to 12.0 with potassium hydroxide to prepare a polishing solution 7X.
　実施例４～７及び比較例７について、実施例１と同様に研磨速度及び平均表面粗さ（Ｒａ）を評価した。実施例１の結果と合わせて、評価結果を表３に示す。 For Examples 4 to 7 and Comparative Example 7, the polishing rate and average surface roughness (Ra) were evaluated in the same manner as in Example 1. Together with the results of Example 1, the evaluation results are shown in Table 3.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
［評価結果］
　表３から明らかなように、ｐＨが１１．５以下のＣＭＰ用研磨液を用いることで研磨後の基体の平均表面粗さ（Ｒａ）が良好であり、また、研磨速度も優れていた。一方、ｐＨが１１．５を超える場合には、平均表面粗さ（Ｒａ）が不良である結果が得られた。 [Evaluation results]
As is clear from Table 3, the average surface roughness (Ra) of the substrate after polishing was good and the polishing rate was excellent by using a CMP polishing liquid having a pH of 11.5 or less. On the other hand, when pH exceeded 11.5, the result that average surface roughness (Ra) was unsatisfactory was obtained.
　以上の結果より、ｐＨが１１．５以下のＣＭＰ用研磨液を用いることで、アルミニウム系材料の表面を高速且つ平滑に研磨できることが確認された。 From the above results, it was confirmed that the surface of the aluminum-based material could be polished smoothly at high speed by using a CMP polishing liquid having a pH of 11.5 or less.
＜実験３：酸化剤の影響＞
（実施例８）
　実施例８では、貯蔵液に含まれる過酸化水素の含有量を０．１０質量％（３０質量％過酸化水素水換算で０．３３質量％）に調整し、貯蔵液を水で２倍に希釈して得られる研磨液中の過酸化水素の含有量を０．０５質量％に調整した以外は、実施例１と同様の手順により貯蔵液８及び研磨液８を作製した。得られた研磨液８のｐＨは１０．０であった。 <Experiment 3: Effect of oxidizing agent>
(Example 8)
In Example 8, the content of hydrogen peroxide contained in the stock solution was adjusted to 0.10% by mass (0.33% by mass in terms of 30% by mass hydrogen peroxide solution), and the stock solution was doubled with water. A storage solution 8 and a polishing solution 8 were prepared by the same procedure as in Example 1 except that the content of hydrogen peroxide in the polishing solution obtained by dilution was adjusted to 0.05 mass%. The resulting polishing liquid 8 had a pH of 10.0.
（実施例９）
　実施例９では、貯蔵液に含まれる過酸化水素の含有量を１．５０質量％（３０質量％過酸化水素水換算で５．００質量％）に調整し、貯蔵液を水で２倍に希釈して得られる研磨液中の過酸化水素の含有量を０．７５質量％に調整した以外は、実施例１と同様の手順により貯蔵液９及び研磨液９を作製した。得られた研磨液９のｐＨは１０．０であった。 Example 9
In Example 9, the content of hydrogen peroxide contained in the stock solution is adjusted to 1.50% by mass (5.00% by mass in terms of 30% by mass hydrogen peroxide solution), and the stock solution is doubled with water. A storage solution 9 and a polishing solution 9 were prepared in the same manner as in Example 1 except that the content of hydrogen peroxide in the polishing solution obtained by dilution was adjusted to 0.75% by mass. The resulting polishing liquid 9 had a pH of 10.0.
（比較例８）
　比較例８では、過酸化水素水を添加しなかったこと以外は、実施例１と同様の手順により貯蔵液８Ｘ及び研磨液８Ｘを作製した。得られた研磨液８ＸのｐＨは１０．０であった。 (Comparative Example 8)
In Comparative Example 8, a storage solution 8X and a polishing solution 8X were prepared by the same procedure as in Example 1 except that no hydrogen peroxide solution was added. The resulting polishing liquid 8X had a pH of 10.0.
　実施例８～９及び比較例８について、実施例１と同様に研磨速度及び平均表面粗さ（Ｒａ）を評価した。実施例１の結果と合わせて、評価結果を表４に示す。 For Examples 8 to 9 and Comparative Example 8, the polishing rate and average surface roughness (Ra) were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4 together with the results of Example 1.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
［評価結果］
　表４から明らかなように、ＣＭＰ用研磨液が酸化剤を含有することで研磨後の基体の平均表面粗さ（Ｒａ）が良好であり、また、研磨速度も優れていた。一方、ＣＭＰ用研磨液が酸化剤を含有しない場合には、平均表面粗さ（Ｒａ）が不良である結果が得られた。 [Evaluation results]
As is apparent from Table 4, the CMP polishing liquid contained an oxidizing agent, whereby the average surface roughness (Ra) of the substrate after polishing was good and the polishing rate was also excellent. On the other hand, when the polishing liquid for CMP did not contain an oxidizer, the average surface roughness (Ra) was poor.
　以上の結果より、酸化剤を含有するＣＭＰ用研磨液を用いることで、アルミニウム系材料に異種元素が添加されている場合（本実施例ではＭｇ（０．４５～０．９質量％）、Ｓｉ（０．２～０．６質量％））であっても、アルミニウム系材料の表面を高速且つ平滑に研磨できることが確認された。 From the above results, by using a CMP polishing liquid containing an oxidizing agent, when a different element is added to the aluminum-based material (Mg (0.45 to 0.9% by mass in this example), Si (0.2 to 0.6% by mass)), it was confirmed that the surface of the aluminum-based material can be polished smoothly at high speed.
　本発明に係るＣＭＰ用研磨液、貯蔵液及びこれらを用いた研磨方法は、半導体基板等の基板、航空機部品、自動車部品等の部品、鉄道車両等の車両、電子機器（携帯型電子機器等）の筐体などのＣＭＰに好適である。 A polishing liquid for CMP, a storage liquid and a polishing method using these according to the present invention include a substrate such as a semiconductor substrate, an aircraft part, a part such as an automobile part, a vehicle such as a railway vehicle, an electronic device (portable electronic device, etc.) It is suitable for CMP of the housing of the above.
　１…測定粒子、１ａ…測定粒子と同面積の真円、２…外接長方形。 1 ... Measurement particle, 1a ... A perfect circle of the same area as the measurement particle, 2 ... A circumscribed rectangle.

Claims (6)

  1. 　アルミニウム系材料を含む基体を研磨するためのＣＭＰ用研磨液であって、
    　砥粒、酸化剤及び液状媒体を含み、
    　前記砥粒の円形度が０．９０以下であり、
    　前記ＣＭＰ用研磨液のｐＨが１１．５以下である、ＣＭＰ用研磨液。     A CMP polishing liquid for polishing a substrate containing an aluminum-based material,
    Including abrasive grains, oxidant and liquid medium,
    The circularity of the abrasive grains is 0.90 or less,
    A CMP polishing liquid, wherein the CMP polishing liquid has a pH of 11.5 or less.
  2. 　前記砥粒の真球度が０．３０以上０．８０以下である、請求項１に記載のＣＭＰ用研磨液。 The polishing slurry for CMP according to claim 1, wherein the sphericity of the abrasive grains is 0.30 or more and 0.80 or less.
  3. 　前記ＣＭＰ用研磨液のｐＨが７．０以上である、請求項１又は２に記載のＣＭＰ用研磨液。 The CMP polishing liquid according to claim 1 or 2, wherein the CMP polishing liquid has a pH of 7.0 or more.
  4. 　請求項１～３のいずれか一項に記載のＣＭＰ用研磨液を得るための貯蔵液であって、
    　液状媒体で希釈することにより前記ＣＭＰ用研磨液が得られる、貯蔵液。     A storage liquid for obtaining the CMP polishing liquid according to any one of claims 1 to 3,
    A storage liquid in which the CMP polishing liquid is obtained by diluting with a liquid medium.
  5. 　請求項１～３のいずれか一項に記載のＣＭＰ用研磨液を用いて、アルミニウム系材料を含む基体を研磨する工程を備える、研磨方法。 A polishing method comprising a step of polishing a substrate containing an aluminum-based material using the CMP polishing liquid according to any one of claims 1 to 3.
  6. 　請求項４に記載の貯蔵液を液状媒体で希釈することにより得られるＣＭＰ用研磨液を用いて、アルミニウム系材料を含む基体を研磨する工程を備える、研磨方法。 A polishing method comprising a step of polishing a substrate containing an aluminum-based material using a polishing slurry for CMP obtained by diluting the stock solution according to claim 4 with a liquid medium.
PCT/JP2013/074132 2012-10-22 2013-09-06 Polishing solution for chemical mechanical polishing (cmp), stock solution, and polishing method WO2014065029A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2012-232759 2012-10-22
JP2012232759 2012-10-22
JP2013-094104 2013-04-26
JP2013094104 2013-04-26

Publications (1)

Publication Number Publication Date
WO2014065029A1 true WO2014065029A1 (en) 2014-05-01

Family

ID=50544410

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/074132 WO2014065029A1 (en) 2012-10-22 2013-09-06 Polishing solution for chemical mechanical polishing (cmp), stock solution, and polishing method

Country Status (2)

Country Link
TW (1) TW201422796A (en)
WO (1) WO2014065029A1 (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008093819A (en) * 2006-04-28 2008-04-24 Kao Corp Polishing liquid composition for magnetic disk substrate
JP2008169102A (en) * 2006-10-12 2008-07-24 Catalysts & Chem Ind Co Ltd Confetti-like silica-based sol and method for producing the same
JP2009091197A (en) * 2007-10-09 2009-04-30 Jgc Catalysts & Chemicals Ltd Warty-surfaced sphere-form inorganic oxide sol, method for producing same, and abrasive containing the sol
JP2009144080A (en) * 2007-12-14 2009-07-02 Kao Corp Polishing liquid composition
JP2010170649A (en) * 2008-12-26 2010-08-05 Kao Corp Polishing liquid composition for magnetic-disk substrate
JP2011131346A (en) * 2009-12-25 2011-07-07 Kao Corp Polishing liquid composition
JP2012104800A (en) * 2010-10-12 2012-05-31 Fujimi Inc Polishing composition
WO2012102187A1 (en) * 2011-01-25 2012-08-02 日立化成工業株式会社 Cmp polishing fluid, method for manufacturing same, method for manufacturing composite particle, and method for polishing base material

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008093819A (en) * 2006-04-28 2008-04-24 Kao Corp Polishing liquid composition for magnetic disk substrate
JP2008169102A (en) * 2006-10-12 2008-07-24 Catalysts & Chem Ind Co Ltd Confetti-like silica-based sol and method for producing the same
JP2009091197A (en) * 2007-10-09 2009-04-30 Jgc Catalysts & Chemicals Ltd Warty-surfaced sphere-form inorganic oxide sol, method for producing same, and abrasive containing the sol
JP2009144080A (en) * 2007-12-14 2009-07-02 Kao Corp Polishing liquid composition
JP2010170649A (en) * 2008-12-26 2010-08-05 Kao Corp Polishing liquid composition for magnetic-disk substrate
JP2011131346A (en) * 2009-12-25 2011-07-07 Kao Corp Polishing liquid composition
JP2012104800A (en) * 2010-10-12 2012-05-31 Fujimi Inc Polishing composition
WO2012102187A1 (en) * 2011-01-25 2012-08-02 日立化成工業株式会社 Cmp polishing fluid, method for manufacturing same, method for manufacturing composite particle, and method for polishing base material

Also Published As

Publication number Publication date
TW201422796A (en) 2014-06-16

Similar Documents

Publication Publication Date Title
TWI307712B (en) Polishing composition
CN1180043C (en) Polishing composition
TWI308588B (en) Method for manufacturing substrate
TW201422798A (en) Polishing composition
JP2006519499A (en) Modular barrier removal polishing slurry
TW201629181A (en) Chemical mechanical polishing slurry
CN107109134A (en) Chemically-mechanicapolish polish purposes of (CMP) composition in base material of the polishing comprising cobalt and/or cobalt alloy
JP2003529663A (en) Polishing method of memory or hard disk surface with amino acid-containing composition
JPWO2016208301A1 (en) Polishing composition
US20050045852A1 (en) Particle-free polishing fluid for nickel-based coating planarization
CN106336812A (en) Slurry composition for polishing tungsten
US7887609B2 (en) Polishing slurry for polishing aluminum film and polishing method for polishing aluminum film using the same
TW201425557A (en) Polishing solution for cmp, stock solution, and polishing method
WO2014065029A1 (en) Polishing solution for chemical mechanical polishing (cmp), stock solution, and polishing method
JP6670715B2 (en) Polishing composition used for polishing a polishing object having a layer containing metal
JP2014018923A (en) Cmp polishing fluid, cmp slurry, and polishing method
JP2015021092A (en) Polishing liquid for cmp, storage liquid and polishing method
JP2014208390A (en) Cmp polishing liquid, storage liquid and polishing method
JP2005223260A (en) Metal abrasive water-based dispersing element containing abrasive grains
JP4955253B2 (en) Polishing composition for polishing device wafer edge, method for producing the same, and polishing method
JP2000269170A (en) Chemical mechanical polishing water system dispersion body for use in manufacturing semiconductor devices
JP2013158860A (en) Polishing fluid for cmp, storage fluid, and polishing method
JP2015153820A (en) Polishing liquid for cmp, stock solution and polishing method
JP2009181690A (en) Method of manufacturing substrate
JP2008288240A (en) SiC CRYSTAL POLISHING METHOD

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13849205

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13849205

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP